Co-reporter:Jiashen Meng, Chaojiang Niu, Linhan Xu, Jiantao Li, Xiong Liu, Xuanpeng Wang, Yuzhu Wu, Xiaoming Xu, Wenyi Chen, Qi Li, Zizhong Zhu, Dongyuan Zhao, and Liqiang Mai
Journal of the American Chemical Society June 21, 2017 Volume 139(Issue 24) pp:8212-8212
Publication Date(Web):May 25, 2017
DOI:10.1021/jacs.7b01942
Carbon nanotubes (CNTs) are of great interest for many potential applications because of their extraordinary electronic, mechanical and structural properties. However, issues of chaotic staking, high cost and high energy dissipation in the synthesis of CNTs remain to be resolved. Here we develop a facile, general and high-yield strategy for the oriented formation of CNTs from metal–organic frameworks (MOFs) through a low-temperature (as low as 430 °C) pyrolysis process. The selected MOF crystals act as a single precursor for both nanocatalysts and carbon sources. The key to the formation of CNTs is obtaining small nanocatalysts with high activity during the pyrolysis process. This method is successfully extended to obtain various oriented CNT-assembled architectures by modulating the corresponding MOFs, which further homogeneously incorporate heteroatoms into the CNTs. Specifically, nitrogen-doped CNT-assembled hollow structures exhibit excellent performances in both energy conversion and storage. On the basis of experimental analyses and density functional theory simulations, these superior performances are attributed to synergistic effects between ideal components and multilevel structures. Additionally, the appropriate graphitic N doping and the confined metal nanoparticles in CNTs both increase the densities of states near the Fermi level and reduce the work function, hence efficiently enhancing its oxygen reduction activity. The viable synthetic strategy and proposed mechanism will stimulate the rapid development of CNTs in frontier fields.
Co-reporter:Mengyu Yan, Xuelei Pan, Peiyao Wang, Fei Chen, Liang He, Gengping Jiang, Junhui Wang, Jefferson Z. Liu, Xu Xu, Xiaobin Liao, Jihui Yang, and Liqiang Mai
Nano Letters July 12, 2017 Volume 17(Issue 7) pp:4109-4109
Publication Date(Web):June 6, 2017
DOI:10.1021/acs.nanolett.7b00855
Transition metal dichalcogenides, such as MoS2 and VSe2 have emerged as promising catalysts for the hydrogen evolution reaction (HER). Substantial work has been devoted to optimizing the catalytic performance by constructing materials with specific phases and morphologies. However, the optimization of adsorption/desorption process in HER is rare. Herein, we concentrate on tuning the dynamics of the adsorption process in HER by applying a back gate voltage to the pristine VSe2 nanosheet. The back gate voltage induces the redistribution of the ions at the electrolyte–VSe2 nanosheet interface, which realizes the enhanced electron transport process and facilitates the rate-limiting step (discharge process) under HER conditions. A considerable low onset overpotential of 70 mV is achieved in VSe2 nanosheets without any chemical treatment. Such unexpected improvement is attributed to the field tuned adsorption-dynamics of VSe2 nanosheet, which is demonstrated by the greatly optimized charge transfer resistance (from 1.03 to 0.15 MΩ) and time constant of the adsorption process (from 2.5 × 10–3 to 5.0 × 10–4 s). Our results demonstrate enhanced catalysis performance in the VSe2 nanosheet by tuning the adsorption dynamics with a back gate, which provides new directions for improving the catalytic activity of non-noble materials.Keywords: adsorption dynamics; Electrochemical catalysis; field effect; hydrogen evolution reaction; VSe2;
Co-reporter:Xiaodan Li, Gaoxiang Wu, Jiewei Chen, Meicheng Li, Wei Li, Tianyue Wang, Bing Jiang, Yue He, Liqiang Mai
Applied Surface Science 2017 Volume 392() pp:297-304
Publication Date(Web):15 January 2017
DOI:10.1016/j.apsusc.2016.09.055
Highlights
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Low-crystallinity molybdenum sulfide coated on carbon nanotubes were synthesized.
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This anode material has unusual electrochemical behaviors compared to typical MoS2.
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It exhibits noticable ascending trends in capacity and superior rate performance.
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The ascending performance can effectively extend the circulation life of batteries.
Co-reporter:Meng Huang, Caiyi Zhang, Chunhua Han, Xiaoming Xu, Xiong Liu, Kang Han, Qi Li, Liqiang Mai
Electrochimica Acta 2017 Volume 254(Volume 254) pp:
Publication Date(Web):10 November 2017
DOI:10.1016/j.electacta.2017.09.077
•V2O5@MV6O15 (M = Na, K) NPs are successfully constructed through a facile “semi-solid” synthetic method.•The V2O5@MV6O15 NPs show much enhanced electrochemical performance as compared to V2O5.•The enhanced performances are attributed to the synergistic effects from the outer MV6O15 layers.•The synergistic effects are confirmed by the in-situ XRD testing results.Synergistic effects of heterostructures can improve electrochemical properties of electrode materials. Herein, core-shell heterogeneous structures of V2O5@MV6O15 (M = Na, K) nanoparticles were designed and successfully synthesized through a facile “semi-solid” method. V2O5@NaV6O15 nanoparticles showed a high discharge capacity of 140 mAh g−1 at 200 mA g−1 which retained 94.9% after 200 cycles, higher than those of V2O5 nanoparticles (116.1 mAh g−1 and 58%). Moreover, through an advanced in-situ XRD technology, the synergistic effect of buffering and smoothing Li+ diffusion from MV6O15 outer layer was revealed. This facile strategy could be widely applied to improve the electrochemical performances of other electrode materials.Download high-res image (123KB)Download full-size image
Co-reporter:Wen Luo;Jean-Jacques Gaumet;Li-Qiang Mai
Rare Metals 2017 Volume 36( Issue 5) pp:321-338
Publication Date(Web):04 May 2017
DOI:10.1007/s12598-017-0899-4
The development of alternative electrode materials with high energy densities and power densities for batteries has been actively pursued to satisfy the power demands for electronic devices and hybrid electric vehicles. Recently, antimony (Sb)-based intermetallic compounds have attracted considerable research interests as new candidate anode materials for high-performance lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to their high theoretical capacity and suitable operating voltage. However, these intermetallic systems undergo large volume change during charge and discharge processes, which prohibits them from practical application. The rational construction of advanced anode with unique structures has been proved to be an effective approach to enhance its electrochemical performance. This review highlights the recent progress in improving and understanding the electrochemical performances of various Sb-based intermetallic compound anodes. The developments of synthesis and construction of Sb-based intermetallic compounds are systematically summarized. The electrochemical performances of various Sb-based intermetallic compound anodes are compared in its typical applications (LIBs or SIBs).
Co-reporter:Chunyu Cui, Qiulong Wei, Liang Zhou, Liqiang Mai, Jianmin Ma
Materials Research Bulletin 2017 Volume 94(Volume 94) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.materresbull.2017.05.046
•MoO2@C nanoflowers are synthesized.•Irregular MoO2@C nanoparticles are synthesized.•MoO2@C nanoflowers deliver a reversible capacity of 172 mAh g−1 at 0.1 A g−1.Sodium-ion batteries (NIBs) have been considered to be the promising alternative to lithium-ion batteries (LIBs) due to the limited availability and uneven distribution of lithium resources. The exploration of anode materials for SIBs was still limited, and transition metal oxides (TMOs) have been widely studied for a long time. MoO2@C nanoflowers were synthesized through a grinding method, followed by an annealing process. In addition, irregular MoO2@C nanoparticles could be synthesized, when the amount of ammonium molybdate was increased by twice while other condition kept the same. With excellent dispersity and structural integrity, the as-obtained MoO2@C nanoflowers deliver a reversible capacity of 172 mAh g−1 at 0.1 A g−1 and a capacity of 166 mA h g−1 after 1000 cycles at 1.0 A g−1.The as-obtained MoO2@C nanoflowers deliver a reversible capacity of 172 mAh g−1 at 0.1 A g−1 and a capacity of 166 mA h g−1 after 1000 cycles at 1.0 A g−1.Download high-res image (179KB)Download full-size image
Co-reporter:Yameng Yin, Fangyu Xiong, Cunyuan Pei, Yanan Xu, Qinyou An, Shuangshuang Tan, Zechao Zhuang, Jinzhi Sheng, Qidong Li, Liqiang Mai
Nano Energy 2017 Volume 41(Volume 41) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.nanoen.2017.09.056
•3D graphene skeleton supported Na3V2O2(PO4)2F microsphere was synthesized by a spray-drying method.•The rGO skeleton can improve the conductivity and buffer volume change during cycling.•The Na3V2O2(PO4)2F/rGO microsphere shows outstanding rate capability and excellent cycling stability.•The Na+ insertion/extraction mechanism is investigated by in-situ XRD and ex-situ HRTEM.Na3V2O2(PO4)2F (NVOPF) is a promising cathode material for sodium-ion batteries (SIBs) due to its high working voltage and theoretical capacity. However, the electrochemical performance is strongly impeded by its poor intrinsic electronic conductivity. Herein, we integrated the high flexible graphene sheets with NVOPF through a spray-drying method to re-construct its structure. The NVOPF nanocrystalline particles are homogeneously embedded in the high electronic conductive graphene framework. As a cathode of SIBs, the robust NVOPF/rGO microsphere composite exhibits excellent electrochemical performance: high specific capacity (127.2 mA h g−1), long-term cycling stability (83.4% capacity retention at 30 C after 2000 cycles) and superior high rate performance (70.3 mA h g−1 at 100 C). Furthermore, the Na+ insertion/extraction mechanism is also investigated by in-situ XRD and ex-situ HRTEM monitor technologies. This work demonstrates that the constructed 3D graphene skeleton serves as a high-efficient electronic conduction matrix and improves the electrochemical properties of electrode materials for advanced energy storage applications.A robust three-dimensional graphene skeleton supported Na3V2O2(PO4)2F microsphere composite was firstly synthesized. The Na3V2O2(PO4)2F/rGO composite exhibits outstanding high-rate capability and excellent long-term cyclical stability as a cathode material for sodium-ion batteries.Download high-res image (235KB)Download full-size image
Co-reporter:Qidong Li, Li Li, Kwadwo Asare Owusu, Wen Luo, Qinyou An, Qiulong Wei, Qingjie Zhang, Liqiang Mai
Nano Energy 2017 Volume 41(Volume 41) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.nanoen.2017.09.022
•Developing a self-sacrificing generated void space method to synthesize a unique yolk-shell mesoporous-CoS@C microsphere.•Mesoporous-CoS@C contains mesoporous CoS yolk and alveolus-like carbon shell.•Mesoporous-CoS@C electrode shows impressive cycling stability and excellent rate capability for both Li+ and Na+ storage.To address the severe volume changes of transition metal chalcogenides that results in inferior cycling performance, herein, a unique yolk-shell microsphere composed of mesoporous cobalt sulfide yolk and alveolus-like carbon shell (M-CoS@C) is constructed. The mesoporous CoS yolks possess large surface area (46.3 m2 g−1) accompanied with the interconnected mesoporous structure, which provide a large contact area to facilitate the permeation of the electrolyte and shorten the ion diffusion path. The alveolus-like carbon shells provide enough void spaces and highly self-adaptive structure to ensure the high stability of the electrode. Owing to the multifunctionality of this unique structure, the M-CoS@C electrode shows impressive cycling stability (790 mA h g−1 after 500 cycles at 1 A g−1 for Li-storage, 532 mA h g−1 after 100 cycles at 0.2 A g−1 for Na-storage) and excellent rate capability (330 mA h g−1 at 20 A g−1 for Li-storage, 190 mA h g−1 at 20 A g−1 for Na-storage). This unique mesoporous yolks@alveolus-like carbon shell structure and the self-sacrificing synthesis method present the effective strategies to promote the utilization of transition metal chalcogenides for practical applications.Download high-res image (185KB)Download full-size image
Co-reporter:Yuhang Dai, Qidong Li, Shuangshuang Tan, Qiulong Wei, Yexin Pan, Xiaocong Tian, Kangning Zhao, Xu Xu, Qinyou An, Liqiang Mai, Qingjie Zhang
Nano Energy 2017 Volume 40(Volume 40) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.nanoen.2017.08.011
•3D vanadium oxide hydrogel is synthesized by a universal liquid exfoliation method.•The vanadium oxide hydrogel cathode displays enhanced electrochemical performance.•The hydrogels/CNTs film delivers remarkable performance at high mass loading.•This work provides a promising route toward flexible electrodes at high mass loading.Ultrathin layered nanomaterials show promising advantages to promote the Li+ diffusion kinetics, however, the self-aggregation/stacking of nanomaterials lead to large capacity loss and limited rate capability, which urgently needs to be addressed. Herein, we report a three-dimensional (3D) novel vanadium oxide (H2V3O8) hydrogel nanostructure composed of intertwined ultrathin nanoribbons and self-coiled nanoscrolls, synthesized by a universal modified liquid exfoliation method. The hydrogels display largely enhanced rate capability and cycling stability, compared to those of the pure nanowires and nanoribbons. Based on the geometrical features of hydrogels, the intertwined hydrogels/carbon nanotubes (CNTs) flexible film is fabricated and delivers remarkable lithium storage performance: a high capacity of 310 mA h g−1 at 0.1 A g−1, excellent rate capability (145 mA h g−1 at 12 A g−1) and stable cycling performance. Moreover, at a high mass loading up to 13 mg cm−2, the hydrogels/CNTs film delivers an area capacity ~ 2.7 mA h cm−2 (at 0.91 mA cm−2), high rate capability (an area capacity of 1.16 mA h cm−2 at 18.2 mA cm−2). The scalable hydrogels/CNTs films provide a promising route towards high performance flexible electrodes at high mass loading.Download high-res image (348KB)Download full-size image
Co-reporter:Xiaoxu Liu, Dongliang Chao, Dapeng Su, Shikun Liu, Liang Chen, Caixia Chi, Jianyi Lin, Ze Xiang Shen, Jiupeng Zhao, Liqiang Mai, Yao Li
Nano Energy 2017 Volume 37(Volume 37) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.nanoen.2017.04.051
•The novel graphene nanowires anchored to 3D graphene foam were synthesized via a template strategy.•The all graphene anode exhibits relatively low discharge plateau, excellent rate capability, and durable tolerance.•The assembling of reduced graphene to graphene nanowire offers new opportunities for energy storage application.Graphene has been extensively investigated as anode material for Li and Na ion batteries due to its excellent physical and chemical performance. Herein, we report a new member of ‘graphene family’, a reduced graphene nanowire on three-dimensional graphene foam (3DGNW). The novel graphene nanowires were synthesized via a template strategy involving reduction and assembly process of nanosized graphene oxides (nGO), pyrolysis of polystyrene spheres (PS) template and catalytic reaction between GO and PS decomposition products. When evaluated as anodes material for Li and Na ion batteries, the 3DGNW exhibits relatively low discharge-voltage plateau, excellent reversible capacity, rate capability, and durable tolerance. For anode of Na ion batteries, a reversible capacity of more than 301 mAh g−1 without capacity fading after 1000 cycles at rate of 1 C were achieved. Even at rate of 20 C, a high reversible capacity of 200 mAh g−1 can be retained. The superior electrochemical performance is ascribed to hierarchical multidimensional graphene architecture, high graphene crystallinity, expansile graphene interlayer distance, and extensively lateral exposed edges/pores, which can promote the electron and ion transport. The realization of assembling reduced graphene sheets to graphene nanowire offers new opportunities for energy storage application of graphene based assembly in future.Download high-res image (197KB)Download full-size image
Co-reporter:Ruimin Sun, Qiulong Wei, Jinzhi Sheng, Changwei Shi, Qinyou An, Sijie Liu, Liqiang Mai
Nano Energy 2017 Volume 35(Volume 35) pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.nanoen.2017.03.036
•We firstly report a novel layer-by-layer stacked VS2 nanosheets as the anode for sodium ion batteries (SIBs). The material is successfully synthesized through a facile one-step polyvinylpyrrolidone assisted assembly method, this method is simple and mass-produced.•The electrode exhibits high initial coulombic efficiency of 85%, superior rate capability (150 mA h g−1 even at 20 A g−1) and long-term cyclability, which stands out among the other layered intercalation SIBs.•A reversible intercalation-type electrochemical reaction during the Na+ insertion/extraction process of VS2 is firstly proved by crystal structure analysis, electrochemical tests, in-situ XRD detections and ex-situ TEM.•The excellent electrochemical performance of the VS2 materials can be attributed to stable framework for the volume swelling/shrink during Na ions insertion/extraction and intercalation pseudocapacitive mechanism, which facilitates the high-rate capability.Sodium ion batteries (SIBs) have been considered as a promising candidate for large scale energy storage systems due to their low cost and reasonable performance. However, developing desirable anode materials with high capacity, excellent cycling stability and high rate capability remains great challenges. Herein, novel layer-by-layer VS2 stacked nanosheets (VS2-SNSs) are synthesized using a facile one-step polyvinylpyrrolidone (PVP) assisted assembly method. With a highly stable orderly stacked layer structure, the VS2 delivers excellent electrochemical performance in SIBs. A reversible discharge capacity of 250 mA h g−1 is obtained at 0.2 A g−1. A high specific capacity of 150 mA h g−1 even at 20 A g−1 is reached (discharged/charged in 27 s). Furthermore, the VS2-SNSs deliver long cycling life with almost no capacity fading even after 600 cycles at 5 A g−1. In-situ XRD and ex-situ TEM characterization reveal that VS2 undertakes a reversible intercalation reaction mechanism. A detailed electrochemical kinetic analysis reveals that the sodium ion charge storage depends on intercalation pseudocapacitive behavior with a high capacitive contribution up to 69% for the total capacity at 1 mV s−1. The impressive electrochemical performance reveals that the VS2 has great potential for the next generation large scale energy storage.Download high-res image (467KB)Download full-size image
Co-reporter:Xuanpeng Wang, Ping Hu, Chaojiang Niu, Jiashen Meng, Xiaoming Xu, Xiujuan Wei, Chunjuan Tang, Wen Luo, Liang Zhou, Qinyou An, Liqiang Mai
Nano Energy 2017 Volume 35(Volume 35) pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.nanoen.2017.03.026
•K0.7Fe0.5Mn0.5O2 is synthesized for the first time through a facile and simply organic-acid-assisted method.•K0.7Fe0.5Mn0.5O2 provides highly reversible layer spacing variations and an ultra-stable skeleton structure during the charge-discharge processes.•K0.7Fe0.5Mn0.5O2 displays both a high capacity (181 mAh g-1) and superior cycling stability (capacity retention of 85% after 1000 cycles).The delivery of cathodes with both high capacity and excellent cycling stability is a great challenge in the development of sodium-ion batteries (SIBs) for energy storage systems. Here, we exploited a novel potassium-ion-intercalated layered iron/manganese-based material (K0.7Fe0.5Mn0.5O2). On the basis of advanced in situ and ex situ X-ray diffraction analysis, we confirm that K0.7Fe0.5Mn0.5O2 can provide highly reversible layer spacing variations and an ultra-stable skeleton structure during the sodiation/desodiation processes. As a result, K0.7Fe0.5Mn0.5O2 displays superior performance, with both high capacity and superior cycling stability, as a cathode for SIBs. A high discharge capacity of 181 mAh g−1 is achieved at 100 mA g−1. Remarkably, even when cycled at high rate of 1000 mA g−1, 85% of the initial discharge capacity is maintained after 1000 cycles. These results indicate that K0.7Fe0.5Mn0.5O2 is a promising candidate for high-capacity and long-life SIBs. Additionally, this work will provide a unique insight into the development of high-performance cathodes for energy storages.Download high-res image (374KB)Download full-size image
Co-reporter:Doudou Guan;Qiang Yu;Chang Xu;Chunjuan Tang;Liang Zhou;Dongyuan Zhao
Nano Research 2017 Volume 10( Issue 12) pp:4351-4359
Publication Date(Web):17 August 2017
DOI:10.1007/s12274-017-1675-3
Trivalent titanium doped titania/carbon (TiO2–x/C) composite microspheres have been prepared by a facile aerosol method (ultrasonic spray pyrolysis) using titanium (IV) bis(ammonium lactato)dihydroxide (TiBALDH) as the sole precursor. The obtained TiO2–x/C microspheres have particle sizes in the range of 400–1,000 nm. When evaluated as anode material for sodium-ion batteries (SIBs), they provide a high reversible capacity of 286 mA·h·g−1 with good cycling performance. A capacity of 249 mA·h·g−1 can be achieved after 180 cycles at 50 mA·g−1, which is more than three times higher than that of white TiO2 microspheres (77 mA·h·g−1). The superior sodium storage performance of these TiO2–x/C composite microspheres can be attributed to the simultaneous introduction of Ti3+ and oxygen vacancies, ultrafine grain size, as well as the conductive carbon matrix. This study provides a facile and effective approach for the production of TiO2–x/C nanocomposites with superior sodium storage performance.
Co-reporter:Zehua Liu;Xiaocong Tian;Xu Xu;Liang He;Mengyu Yan;Chunhua Han;Yan Li
Nano Research 2017 Volume 10( Issue 7) pp:2471-2481
Publication Date(Web):27 March 2017
DOI:10.1007/s12274-017-1451-4
Planar micro-supercapacitors show great potential as the energy storage unit in miniaturized electronic devices. Asymmetric structures have been widely investigated in micro-supercapacitors, and carbon-based materials are commonly applied in the electrodes. To integrate different metal oxides in both electrodes in micro-supercapacitors, the critical challenge is the pairing of different faradic metal oxides. Herein, we propose a strategy of matching the voltage and capacitance of two faradic materials that are fully integrated into one high-performance asymmetric micro-supercapacitor by a facile and controllable fabrication process. The fabricated micro-supercapacitors employ MnO2 as the positive active material and Fe2O3 as the negative active material, respectively. The planar asymmetric micro-supercapacitors possess a high capacitance of 60 F·cm–3, a high energy density of 12 mW·h·cm–3, and a broad operation voltage range up to 1.2 V.
Co-reporter:Jinzhi Sheng;Chen Peng;Yanan Xu;Haoying Lyu;Xu Xu;Qinyou An
Advanced Energy Materials 2017 Volume 7(Issue 17) pp:
Publication Date(Web):2017/09/01
DOI:10.1002/aenm.201700247
To accommodate the decreasing lithium resource and ensure continuous development of energy storage industry, sodium-based batteries are widely studied to inherit the next generation of energy storage devices. In this work, a novel Na super ionic conductor type KTi2(PO4)3/carbon nanocomposite is designed and fabricated as sodium storage electrode materials, which exhibits considerable reversible capacity (104 mAh g−1 under the rate of 1 C with flat voltage plateaus at ≈2.1 V), high-rate cycling stability (74.2% capacity retention after 5000 cycles at 20 C), and ultrahigh rate capability (76 mAh g−1 at 100 C) in sodium ion batteries. Besides, the maximum ability for sodium storage is deeply excavated by further investigations about different voltage windows in half and full sodium ion cells. Meanwhile, as cathode material in sodium-magnesium hybrid batteries, the KTi2(PO4)3/carbon nanocomposite also displays good electrochemical performances (63 mAh g−1 at the 230th cycle under the voltage window of 1.0–1.9 V). The results demonstrate that the KTi2(PO4)3/carbon nanocomposite is a promising electrode material for sodium ion storage, and lay theoretical foundations for the development of new type of batteries.
Co-reporter:Pan He;Mengyu Yan;Guobin Zhang;Ruimin Sun;Lineng Chen;Qinyou An
Advanced Energy Materials 2017 Volume 7(Issue 11) pp:
Publication Date(Web):2017/06/01
DOI:10.1002/aenm.201601920
An aqueous Zn/VS2 battery is designed, which consists of a VS2 cathode, a zinc anode, and a mild ZnSO4 aqueous electrolyte. The battery delivers a high capacity, and exhibits long-term cyclic stability due to the large layer spacing and high conductivity of VS2. A reversible insertion/extraction of Zn2+ is observed during the discharge/charge process.
Co-reporter:Liqiang Mai;Qingjie Zhang;Ce-Wen Nan
Advanced Materials 2017 Volume 29(Issue 20) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201701082
First page of article
Co-reporter:Qiulong Wei;Fangyu Xiong;Shuangshuang Tan;Lei Huang;Esther H. Lan;Bruce Dunn
Advanced Materials 2017 Volume 29(Issue 20) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201602300
Electrochemical energy storage technology is of critical importance for portable electronics, transportation and large-scale energy storage systems. There is a growing demand for energy storage devices with high energy and high power densities, long-term stability, safety and low cost. To achieve these requirements, novel design structures and high performance electrode materials are needed. Porous 1D nanomaterials which combine the advantages of 1D nanoarchitectures and porous structures have had a significant impact in the field of electrochemical energy storage. This review presents an overview of porous 1D nanostructure research, from the synthesis by bottom-up and top-down approaches with rational and controllable structures, to several important electrochemical energy storage applications including lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, lithium-oxygen batteries and supercapacitors. Highlights of porous 1D nanostructures are described throughout the review and directions for future research in the field are discussed at the end.
Co-reporter:Xue Liu;Jia-Qi Huang;Qiang Zhang
Advanced Materials 2017 Volume 29(Issue 20) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201601759
Lithium–sulfur (Li–S) batteries with high energy density and long cycle life are considered to be one of the most promising next-generation energy-storage systems beyond routine lithium-ion batteries. Various approaches have been proposed to break down technical barriers in Li–S battery systems. The use of nanostructured metal oxides and sulfides for high sulfur utilization and long life span of Li–S batteries is reviewed here. The relationships between the intrinsic properties of metal oxide/sulfide hosts and electrochemical performances of Li–S batteries are discussed. Nanostructured metal oxides/sulfides hosts used in solid sulfur cathodes, separators/interlayers, lithium-metal-anode protection, and lithium polysulfides batteries are discussed respectively. Prospects for the future developments of Li–S batteries with nanostructured metal oxides/sulfides are also discussed.
Co-reporter:Liang Zhou;Zechao Zhuang;Huihui Zhao;Mengting Lin;Dongyuan Zhao
Advanced Materials 2017 Volume 29(Issue 20) pp:
Publication Date(Web):2017/05/01
DOI:10.1002/adma.201602914
Intricate hollow structures garner tremendous interest due to their aesthetic beauty, unique structural features, fascinating physicochemical properties, and widespread applications. Here, the recent advances in the controlled synthesis are discussed, as well as applications of intricate hollow structures with regard to energy storage and conversion. The synthetic strategies toward complex multishelled hollow structures are classified into six categories, including well-established hard- and soft-templating methods, as well as newly emerging approaches based on selective etching of “soft@hard” particles, Ostwald ripening, ion exchange, and thermally induced mass relocation. Strategies for constructing structures beyond multishelled hollow structures, such as bubble-within-bubble, tube-in-tube, and wire-in-tube structures, are also covered. Niche applications of intricate hollow structures in lithium-ion batteries, Li–S batteries, supercapacitors, Li–O2 batteries, dye-sensitized solar cells, photocatalysis, and fuel cells are discussed in detail. Some perspectives on the future research and development of intricate hollow structures are also provided.
Co-reporter:Jian Tan;Yulai Han;Liang He;Yixiao Dong;Xu Xu;Dongna Liu;Haowu Yan;Qiang Yu;Congyun Huang
Journal of Materials Chemistry A 2017 vol. 5(Issue 45) pp:23620-23627
Publication Date(Web):2017/11/21
DOI:10.1039/C7TA07024A
Herein we propose a low-cost, one-step synthesis of magnesium hydroxide (Mg(OH)2) that is deposited on polyacrylonitrile (PAN) nanofibers by electrospinning. Following carbonization and etching, an in situ N-doped mesoporous carbon nanofiber (N-MCNF) network is synthesized. The synthesized flexible network is employed as a freestanding electrode for supercapacitors. The as-constructed supercapacitor based on the N-MCNFs prepared at 900 °C (N-MCNFs-900) can deliver excellent performance with an ultrahigh specific capacitance of 327.3 F g−1 at a current density of 1.0 A g−1, and remarkable cycling stability, e.g., only about 7% loss after 10 000 cycles at a constant high charging–discharging current of 20 A g−1 in 6 M KOH aqueous electrolyte. The flexible network consisting of N-MCNFs-900 as the electrode material with long cycling stability is highly promising for next-generation high-performance supercapacitors.
Co-reporter:Jun Dong;Yalong Jiang;Qidong Li;Qiulong Wei;Wei Yang;Shuangshuang Tan;Xu Xu;Qinyou An
Journal of Materials Chemistry A 2017 vol. 5(Issue 22) pp:10827-10835
Publication Date(Web):2017/06/06
DOI:10.1039/C7TA00463J
Titanium oxynitride mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized, based on an anion exchange process. By investigating the electrochemical performance, it is found to exhibit high pseudocapacitive sodium storage performance, demonstrated by kinetic analysis and experimental characterizations. Subsequently, the assembled asymmetric hybrid sodium ion capacitor (AC//Ti(O,N)) exhibits high energy and power densities. Our work proposes the high pseudocapacitance in non-aqueous sodium ion system is very promising for high-power and low-cost energy storage applications.
Co-reporter:Jian Tan;Dongna Liu;Xu Xu
Nanoscale (2009-Present) 2017 vol. 9(Issue 48) pp:19001-19016
Publication Date(Web):2017/12/14
DOI:10.1039/C7NR06819K
Rechargeable lithium–sulfur (Li–S) batteries have recently attracted global research interest due to their high theoretical specific capacity and energy density. To improve the performance and cycling stability of Li–S batteries, a clear understanding of the electrochemical reaction process and the degradation mechanisms of the sulfur redox chemistry are extremely important. In the past few decades, various advanced in situ/operando characterization tools have emerged, which have facilitated the understanding of the degradation mechanisms and the further development of high-performance Li–S batteries. In this review, we have summarized recent significant advances in in situ/operando characterization techniques for Li–S batteries. In particular, because of the existence of the soluble polysulfide species during the charge/discharge process, many creative ideas have been introduced into in situ/operando characterization of the electrochemical process in Li–S batteries.
Co-reporter:Xinyu Ma;Shuxuan Feng;Liang He;Mengyu Yan;Xiaocong Tian;Yanxi Li;Chunjuan Tang;Xufeng Hong
Nanoscale (2009-Present) 2017 vol. 9(Issue 32) pp:11765-11772
Publication Date(Web):2017/08/17
DOI:10.1039/C7NR01789H
On-chip electrochemical energy storage devices have attracted growing attention due to the decreasing size of electronic devices. Various approaches have been applied for constructing the microsupercapacitors. However, the microfabrication of high-performance microsupercapacitors by conventional and fully compatible semiconductor microfabrication technologies is still a critical challenge. Herein, unique three-dimensional (3D) Co3O4 nanonetwork microelectrodes formed by the interconnection of Co3O4 nanosheets are constructed by controllable physical vapor deposition combined with rapid thermal annealing. This construction process is an all dry and rapid (≤5 minutes) procedure. Afterward, by sputtering highly electrically conductive Pt nanoparticles on the microelectrodes, the 3D Co3O4/Pt nanonetworks based microsupercapacitor is fabricated, showing a high volume capacitance (35.7 F cm−3) at a scan rate of 20 mV s−1 due to the unique interconnected structures, high electrical conductivity and high surface area of the microelectrodes. This microfabrication process is also used to construct high-performance flexible microsupercapacitors, and it can be applied in the construction of wearable devices. The proposed strategy is completely compatible with the current semiconductor microfabrication and shows great potential in the applications of the large-scale integration of micro/nano and wearable devices.
Co-reporter:Zhaohuai Li;Qiu He;Liang He;Ping Hu;Wei Li;Haowu Yan;Xianzhou Peng;Congyun Huang
Journal of Materials Chemistry A 2017 vol. 5(Issue 8) pp:4183-4189
Publication Date(Web):2017/02/21
DOI:10.1039/C6TA10583A
Silicon oxide (SiOx) shows great potential for lithium ion battery (LIB) anodes due to its high capacity, environmental friendliness, low cost and high abundance. Herein, we used low-cost mesoporous silica spheres to synthesize core–shell structured porous carbon-coated SiOx nanowires (pC–SiOx NWs) as a new LIB anode through a novel self-sacrificed method. The one-dimensional structure can accommodate large volume expansion without breaking. The porous carbon coating hinders the penetration of the electrolyte into pC–SiOx NWs and formation of a stable solid-electrolyte interphase (SEI) film on the external surface of pC–SiOx NWs. As a result, the composite shows excellent cycling stability with high reversible specific capacities of 1060 mA h g−1 (100 cycles) and 623 mA h g−1 (150 cycles) at current densities of 100 mA g−1 and 500 mA g−1, respectively. The proposed facile and scalable synthesis is highly competitive for large-scale applications in lithium storage devices/systems.
Co-reporter:Guobin Zhang;Tengfei Xiong;Liang He;Mengyu Yan
Journal of Materials Science 2017 Volume 52( Issue 7) pp:3697-3718
Publication Date(Web):2017 April
DOI:10.1007/s10853-016-0732-8
In situ X-ray diffraction (XRD), as a widely used tool in probing the structure evolution in electrochemical process as well as the energy storage and capacity fading mechanism, has shown great effects with optimizing and building better batteries. Based on the research progresses of in situ XRD in recent years, we give a review of the development and the utilization of this powerful tool in understanding the complex electrochemical mechanisms. The studies on in situ XRD are divided into three sections based on the reaction mechanisms: alloying, conversion, and intercalation reactions in lithium-ion batteries. The alloying reaction, in which lithium ions insert into Si, Sb, and Ge is firstly reviewed, followed by a discussion about the recent development of in situ XRD on conversion reaction materials (including metal oxides and metal sulfides) and intercalation reaction materials (including cathode materials and some structure-stable anode materials). As for sodium-ion batteries, we divide these researches on structure evolution into two categories: cathode and anode materials. Finally, the future development of in situ XRD is discussed.
Co-reporter:Shaohua Zhu, Qidong Li, Qiulong Wei, Ruimin Sun, Xiaoqing Liu, Qinyou An, and Liqiang Mai
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 1) pp:
Publication Date(Web):December 12, 2016
DOI:10.1021/acsami.6b10143
In this article, we report NiSe2 nanooctahedra as a promising anode material for sodium-ion batteries (SIBs). They exhibit outstanding long-term cyclic stability (313 mAh/g after 4000 cycles at 5 A/g) and excellent high-rate capability (175 mAh/g at 20 A/g). Besides, the initial Coulombic efficiency of NiSe2 is also very impressive (over 90%). Such remarkable performances are attributed to good conductivity, structural stability, and the pseudocapacitive behavior of the NiSe2. Furthermore, the sodium ion storage mechanism of NiSe2 is first investigated by in situ XRD and ex situ XRD. These highlights give NiSe2 a competitive strength for rechargeable SIBs.Keywords: anode; high-rate; long-term cycle life; NiSe2 nanooctahedra; sodium-ion batteries;
Co-reporter:Xiujuan Wei;Chunjuan Tang;Qinyou An;Mengyu Yan;Xuanpeng Wang;Ping Hu
Nano Research 2017 Volume 10( Issue 9) pp:3202-3211
Publication Date(Web):25 May 2017
DOI:10.1007/s12274-017-1537-z
Sodium-ion batteries (SIBs) have great promise for sustainable and economical energy-storage applications. Nevertheless, it is a major challenge to develop anode materials with high capacity, high rate capability, and excellent cycling stability for them. In this study, FeSe2 clusters consisting of nanorods were synthesized by a facile hydrothermal method, and their sodium-storage properties were investigated with different electrolytes. The FeSe2 clusters delivered high electrochemical performance with an ether-based electrolyte in a voltage range of 0.5–2.9 V. A high discharge capacity of 515 mAh·g–1 was obtained after 400 cycles at 1 A·g–1, with a high initial columbic efficiency of 97.4%. Even at an ultrahigh rate of 35 A·g–1, a specific capacity of 128 mAh·g–1 was achieved. Using calculations, we revealed that the pseudocapacitance significantly contributed to the sodium-ion storage, especially at high current rates, leading to a high rate capability. The high comprehensive performance of the FeSe2 clusters makes them a promising anode material for SIBs.
Co-reporter:Limin Zhou, Kai Zhang, Jinzhi Sheng, Qinyou An, Zhanliang Tao, Yong-Mook Kang, Jun Chen, Liqiang Mai
Nano Energy 2017 Volume 35(Volume 35) pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.nanoen.2017.03.052
•The embedded hybrid architecture of the 7-CoS/C is favorable for relieving volume expansion and immobilizing the CoS nanoparticles sites.•The effect of different electrolyte on the 7-CoS/C/Na system was investigated.•The variation of structure and valence in Na+ insertion/extraction process of the 7-CoS/C is presented by ex situ XANES.•The unique structural feature of the 7-CoS/C reveals obvious advantages at more than 1 A g−1 compared with other anode materials.Considering inherent large structural deterioration of conversion-type anode materials during repeated sodiation/desodiation process, the ingenious integration of both nanostructure engineering and chemical hybridization is highly desirable and challenging. Here, ultrafine CoS nanoparticles embedded in porous carbon nanorods (denoted as 7-CoS/C) were facilely fabricated via simultaneous in-situ carbonization and sulfidation of Co-metal organic frameworks (Co-MOF) and have been applied as anode materials for sodium-ion batteries (SIBs). Benefiting from the advantageous embedding architecture between the nanoparticles and porous nanorods, the 7-CoS/C delivers long-term cycling stability (542 mAh g−1 after 2000 cycles with a capacity retention of 91.4% at 1 A g−1) and excellent rate performance (discharge capacities of 510 mAh g−1 at 5 A g−1 and 356 mAh g−1 even at 40 A g−1), which is proved to be characterized of partial pseudocapacitive behaviors during the sodiation/desodiation process. In addition, Na3V2(PO4)3/7-CoS/C full cell with excessive amount of Na3V2(PO4)3 has been assembled and exhibits a capacity of 352 mAh g−1 at 0.5 A g−1. This meaningful approach can be extended to build embedded porous structure of other hybrid composites for next-generation energy-storage technology.Download high-res image (337KB)Download full-size image
Co-reporter:Min Ling, Liang Zhang, Tianyue Zheng, Jun Feng, Jinghua Guo, Liqiang Mai, Gao Liu
Nano Energy 2017 Volume 38(Volume 38) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.nanoen.2017.05.020
•The nucleophilic substitution reaction of polysulfide on the binders is verified by in situ UV-vis spectroscopy.•The immobilization of polysulfide in the electrode is verified by in situ synchrotron based sulfur K-edge X-ray absorption spectroscopy.•Industrial grade sulfur is used without additional processing, and the stable cycling loading is above 6 mAh/cm2.•The polymeric binder is a biodegradable natural material, and can be used directly in commercial battery.Polysulfide shuttling has been the primary cause of failure in lithium-sulfur (Li-S) battery cycling. Here, we demonstrate an nucleophilic substitution reaction between polysulfides and binder functional groups can unexpectedly immobilizes the polysulfides. The substitution reaction is verified by UV–visible spectra and X-ray photoelectron spectra. The immobilization of polysulfide is in situ monitored by synchrotron based sulfur K-edge X-ray absorption spectra. The resulting electrodes exhibit initial capacity up to 20.4 mAh/cm2, corresponding to 1199.1 mAh/g based on a micron-sulfur mass loading of 17.0 mg/cm2. The micron size sulfur transformed into nano layer coating on the cathode binder during cycling. Directly usage of nano-size sulfur promotes higher capacity of 33.7 mAh/cm2, which is the highest areal capacity reported in Li-S battery. This enhance performance is due to the reduced shuttle effect by covalently binding of the polysulfide with the polymer binder.Nature polymer carrageenan from sea weeds is widely used thickening agent for shaping forming in food industry. Carrageenan can form covalent bonding with polysulfide to prevent excessive polysulfide dissolution and migration into the electrolyte. When carrageenan is used in composite electrode as polymer binder to shape the composite electrode, the dissolution of sulfur into polysulfide is immediately capture by carrageenan to prevent further migration of polysulfide beyond the cathode location.Download high-res image (205KB)Download full-size image
Co-reporter:Chunhua Han;Baoxuan Zhang;Kangning Zhao;Jiashen Meng;Qiu He;Pan He;Wei Yang;Qi Li
Chemical Communications 2017 vol. 53(Issue 69) pp:9542-9545
Publication Date(Web):2017/08/24
DOI:10.1039/C7CC05406H
SnO2 nanotubes are synthesized via an oxalate-assisted “redox etching and precipitating” route between MnOOH nanowires and Sn2+ ions. The addition of oxalate is found to be crucial to guide the formation of uniform SnO2 nanotubes. To further improve the conductivity and stability, the as-obtained SnO2 nanotubes are coated with a thin carbon layer. The resulting carbon-confined SnO2 nanotubes possess superior rate performance as an anode material for lithium-ion batteries.
Co-reporter:Xiangyu Jiang;Jiangang Feng;Lei Huang;Yuchen Wu;Bin Su;Wensheng Yang;Lei Jiang
Advanced Materials 2016 Volume 28( Issue 32) pp:6952-6958
Publication Date(Web):
DOI:10.1002/adma.201601609
Co-reporter:Yanan Xu;Qiulong Wei;Chang Xu;Qidong Li;Qinyou An;Pengfei Zhang;Jinzhi Sheng;Liang Zhou
Advanced Energy Materials 2016 Volume 6( Issue 14) pp:
Publication Date(Web):
DOI:10.1002/aenm.201600389
Na3V2(PO4)3 (NVP) is regarded as a promising cathode for advanced sodium-ion batteries (SIBs) due to its high theoretical capacity and stable sodium (Na) super ion conductor (NASICON) structure. However, strongly impeded by its low electronic conductivity, the general NVP delivers undesirable rate capacity and fails to meet the demands for quick charge. Herein, a novel and facile synthesis of layer-by-layer NVP@reduced graphene oxide (rGO) nanocomposite is presented through modifying the surface charge of NVP gel precursor. The well-designed layered NVP@rGO with confined NVP nanocrystal in between rGO layers offers high electronic and ionic conductivity as well as stable structure. The NVP@rGO nanocomposite with merely ≈3.0 wt% rGO and 0.5 wt% amorphous carbon, yet exhibits extraordinary electrochemical performance: a high capacity (118 mA h g−1 at 0.5 C attaining the theoretical value), a superior rate capability (73 mA h g−1 at 100 C and even up to 41 mA h g−1 at 200 C), ultralong cyclability (70.0% capacity retention after 15 000 cycles at 50 C), and stable cycling performance and excellent rate capability at both low and high operating temperatures. The proposed method and designed layer-by-layer active nanocrystal@rGO strategy provide a new avenue to create nanostructures for advanced energy storage applications.
Co-reporter:Ping Hu, Mengyu Yan, Xuanpeng Wang, Chunhua Han, Liang He, Xiujuan Wei, Chaojiang Niu, Kangning Zhao, Xiaocong Tian, Qiulong Wei, Zijia Li, and Liqiang Mai
Nano Letters 2016 Volume 16(Issue 3) pp:1523-1529
Publication Date(Web):February 16, 2016
DOI:10.1021/acs.nanolett.5b03576
Graphene has been widely used to enhance the performance of energy storage devices due to its high conductivity, large surface area, and excellent mechanical flexibility. However, it is still unclear how graphene influences the electrochemical performance and reaction mechanisms of electrode materials. The single-nanowire electrochemical probe is an effective tool to explore the intrinsic mechanisms of the electrochemical reactions in situ. Here, pure MnO2 nanowires, reduced graphene oxide/MnO2 wire-in-scroll nanowires, and porous graphene oxide/MnO2 wire-in-scroll nanowires are employed to investigate the capacitance, ion diffusion coefficient, and charge storage mechanisms in single-nanowire electrochemical devices. The porous graphene oxide/MnO2 wire-in-scroll nanowire delivers an areal capacitance of 104 nF/μm2, which is 4.0 and 2.8 times as high as those of reduced graphene oxide/MnO2 wire-in-scroll nanowire and MnO2 nanowire, respectively, at a scan rate of 20 mV/s. It is demonstrated that the reduced graphene oxide wrapping around the MnO2 nanowire greatly increases the electronic conductivity of the active materials, but decreases the ion diffusion coefficient because of the shielding effect of graphene. By creating pores in the graphene, the ion diffusion coefficient is recovered without degradation of the electron transport rate, which significantly improves the capacitance. Such single-nanowire electrochemical probes, which can detect electrochemical processes and behavior in situ, can also be fabricated with other active materials for energy storage and other applications in related fields.
Co-reporter:Yanzhu Luo, Xu Xu, Xiaocong Tian, Qiulong Wei, Mengyu Yan, Kangning Zhao, Xiaoming Xu and Liqiang Mai
Journal of Materials Chemistry A 2016 vol. 4(Issue 14) pp:5075-5080
Publication Date(Web):02 Mar 2016
DOI:10.1039/C6TA01339B
Hollow microspheres with a high surface area, sufficient void space, and short ion/electron transport distance have attracted much attention as a superior electrode structure for high-rate lithium-ion batteries. In this work, a facile and low-cost hydrothermal approach followed by annealing is developed to synthesize Co3V2O8 interconnected hollow microspheres, which are able to endure an extremely high current density of 20 A g−1 and achieve a reversible discharge capacity of 320 mA h g−1. Furthermore, a stable capacity of 424 mA h g−1 can be obtained after 300 cycles at 10 A g−1. Such remarkable rate capability and cycling performance make the Co3V2O8 interconnected hollow microspheres a promising anode material for lithium-ion batteries.
Co-reporter:Jiashen Meng, Ziang Liu, Chaojiang Niu, Xiaoming Xu, Xiong Liu, Guobin Zhang, Xuanpeng Wang, Meng Huang, Yang Yu and Liqiang Mai
Journal of Materials Chemistry A 2016 vol. 4(Issue 13) pp:4893-4899
Publication Date(Web):02 Mar 2016
DOI:10.1039/C6TA00556J
Layered metal vanadates, especially alkali metal vanadates, have been extensively studied in energy storage. Generally, vanadates exhibit more stable electrochemical performance than pristine vanadium oxides, and different vanadates also vary in the performance. However, the detailed mechanisms of the variation in the performance of vanadates and vanadium oxides are poorly explored. Here we choose and construct three typical layered vanadium-based nanowires (V2O5, KV3O8 and K0.25V2O5), and investigate the origin of the enhanced electrochemical performance of the potassium vanadates compared to V2O5, based on crystal structure analysis, electrochemical tests, ex situ ICP measurements and in situ XRD detections. We demonstrate a synergistic effect between layer surface configurations and K ions of potassium vanadate nanowires, which leads to the great improvement in electrochemical stability of K0.25V2O5. The layer surface configuration of K0.25V2O5 only consists of single-connected oxygen atoms, which provides strong interaction with the K ions. And the stabilized K ions act as “pillars” between interlayers to protect the layered structures from collapse in the charge/discharge process. This work provides a further insight into alkali metal vanadates, and benefits the design of ideal electrode materials in the energy storage field.
Co-reporter:Youyu Jiang, Shengqiang Xiao, Biao Xu, Chun Zhan, Liqiang Mai, Xinhui Lu, and Wei You
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 18) pp:11658
Publication Date(Web):April 22, 2016
DOI:10.1021/acsami.6b02824
Herein, a successful application of V2O5·nH2O film as hole transporting layer (HTL) instead of PEDOT:PSS in polymer solar cells is demonstrated. The V2O5·nH2O layer was spin-coated from V2O5·nH2O sol made from melting-quenching sol–gel method by directly using vanadium oxide powder, which is readily accessible and cost-effective. V2O5·nH2O (n ≈ 1) HTL is found to have comparable work function and smooth surface to that of PEDOT:PSS. For the solar cell containing V2O5·nH2O HTL and the active layer of the blend of a novel polymer donor (PBDSe-DT2PyT) and the acceptor of PC71BM, the PCE was significantly improved to 5.87% with a 30% increase over 4.55% attained with PEDOT:PSS HTL. Incorporation of V2O5·nH2O as HTL in the polymer solar cell was found to enhance the crystallinity of the active layer, electron-blocking at the anode and the light-harvest in the wavelength range of 400–550 nm in the cell. V2O5·nH2O HTL improves the charge generation and collection and suppress the charge recombination within the PBDSe-DT2PyT:PC71BM solar cell, leading to a simultaneous enhancement in Voc, Jsc, and FF. The V2O5·nH2O HTL proposed in this work is envisioned to be of great potential to fabricate highly efficient PSCs with low-cost and massive production.Keywords: hole transporting layer; melting-quenching sol−gel method; PEDOT:PSS; polymer solar cell; vanadium(V) oxide hydrate
Co-reporter:Yanzhu Luo, Xu Xu, Yuxiang Zhang, Chih-Yen Chen, Liang Zhou, Mengyu Yan, Qiulong Wei, Xiaocong Tian, and Liqiang Mai
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 4) pp:2812
Publication Date(Web):January 11, 2016
DOI:10.1021/acsami.5b11510
Hierarchical Co2V2O7 nanosheets consisted of interconnected nanoparticles are synthesized by a facile method using graphene oxide as the template. The electrochemical reaction mechanism of the Co2V2O7 nanosheets is thoroughly investigated by in situ XRD and ex situ TEM. The initial Co2V2O7 transforms into CoO nanoparticles and vanadium oxides in the first cycle, and the following reversible conversion reaction mainly occurs between CoO and Co and lithiation/delithiation of the vanadium oxides. The Co2V2O7 nanosheet displays a high reversible capacity (962 mAh/g at 0.5 A/g) and remarkable high rate capability. When cycled at 5.0 A/g, a reversible capacity of 441 mAh/g can be retained after 900 cycles. The stable high capacity and excellent rate capability make the hierarchical Co2V2O7 nanosheets a promising anode material for lithium-ion batteries.Keywords: cobalt vanadium oxide; graphene oxide; hierarchical structure; lithium storage mechanism; lithium-ion battery
Co-reporter:Qiulong Wei, Yanan Xu, Qidong Li, Shuangshuang Tan, Wenhao Ren, Qinyou An and Liqiang Mai
Chemical Communications 2016 vol. 52(Issue 56) pp:8730-8732
Publication Date(Web):08 Jun 2016
DOI:10.1039/C6CC03629E
Novel layered Li3V2(PO4)3/rGO&C sheets are synthesized by novel interfacial modified assembly, freeze-drying and confined annealing processes. The uniform LVP layers are alternated with rGO&C layers to form the composite layered structure, providing effective electron and ion transport. As a lithium-ion battery cathode, the composite displays excellent electrochemical performance.
Co-reporter:Lei Zhang, Kangning Zhao, Yanzhu Luo, Yifan Dong, Wangwang Xu, Mengyu Yan, Wenhao Ren, Liang Zhou, Longbing Qu, and Liqiang Mai
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 11) pp:7139
Publication Date(Web):March 3, 2016
DOI:10.1021/acsami.6b00596
Metal vanadates suffer from fast capacity fading in lithium-ion batteries especially at a high rate. Pseudocapacitance, which is associated with surface or near-surface redox reactions, can provide fast charge/discharge capacity free from diffusion-controlled intercalation processes and is able to address the above issue. In this work, we report the synthesis of macroporous CoV2O6 nanosheets through a facile one-pot method via acetylene black induced heterogeneous growth. When applied as lithium-ion battery anode, the macroporous CoV2O6 nanosheets show typical features of pseudocapacitive behavior: (1) currents that are mostly linearly dependent on sweep rate and (2) redox peaks whose potentials do not shift significantly with sweep rate. The macroporous CoV2O6 nanosheets display a high reversible capacity of 702 mAh g–1 at 200 mA g–1, excellent cyclability with a capacity retention of 89% (against the second cycle) after 500 cycles at 500 mA g–1, and high rate capability of 453 mAh g–1 at 5000 mA g–1. We believe that the introduction of pseudocapacitive properties in lithium battery is a promising direction for developing electrode materials with high-rate capability.Keywords: CoV2O6; heterogeneous growth; lithium-ion battery; macroporous nanosheet; pseudocapacitance
Co-reporter:Zhaoyang Wang, Jiantao Li, Xiaocong Tian, Xuanpeng Wang, Yang Yu, Kwadwo Asare Owusu, Liang He, and Liqiang Mai
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 30) pp:19386
Publication Date(Web):July 12, 2016
DOI:10.1021/acsami.6b03392
Exploring non-noble and high-efficiency electrocatalysts is critical to large-scale industrial applications of electrochemical water splitting. Currently, nickel-based selenide materials are promising candidates for oxygen evolution reaction due to their low cost and excellent performance. In this work, we report the porous nickel–iron bimetallic selenide nanosheets ((Ni0.75Fe0.25)Se2) on carbon fiber cloth (CFC) by selenization of the ultrathin NiFe-based nanosheet precursor. The as-prepared three-dimensional oxygen evolution electrode exhibits a small overpotential of 255 mV at 35 mA cm–2 and a low Tafel slope of 47.2 mV dec–1 and keeps high stability during a 28 h measurement in alkaline solution. The outstanding catalytic performance and strong durability, in comparison to the advanced non-noble metal catalysts, are derived from the porous nanostructure fabrication, Fe incorporation, and selenization, which result in fast charge transportation and large electrochemically active surface area and enhance the release of oxygen bubbles from the electrode surface.Keywords: carbon fiber cloth (CFC); electrochemical catalyst; nickel−iron bimetallic selenide; oxygen evolution; porous nanosheets
Co-reporter:Wen Luo, Pengfei Zhang, Xuanpeng Wang, Qidong Li, Yifan Dong, Jingchen Hua, Liang Zhou, Liqiang Mai
Journal of Power Sources 2016 Volume 304() pp:340-345
Publication Date(Web):1 February 2016
DOI:10.1016/j.jpowsour.2015.11.047
•SbNPs@3D-C was achieved by template-assisted freeze-drying and carbonization.•SbNPs@3D-C showed nano-sized Sb particles anchored in 3D carbon network structure.•Long-life performance (500 cycles) and superior rate ability were demonstrated.•NaCl template-assisted strategy combined with freeze-drying can be widely extended.A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g−1 at 100 mA g−1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g−1) as well as superior rate capability (270 mAh g−1 at 2000 mA g−1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next “beyond lithium” battery generation.
Co-reporter:Di Wang, Qiulong Wei, Jinzhi Sheng, Ping Hu, Mengyu Yan, Ruimin Sun, Xiaoming Xu, Qinyou An and Liqiang Mai
Physical Chemistry Chemical Physics 2016 vol. 18(Issue 17) pp:12074-12079
Publication Date(Web):29 Mar 2016
DOI:10.1039/C6CP00745G
Sodium ion batteries (SIBs) have emerged as a potential candidate to succeed lithium ion batteries (LIBs), because of the abundant sodium resources on earth. Layered vanadium oxides are regarded as the promising candidates for SIBs because of their large interlayer spacing, high theoretical specific capacity, abundant sources and low cost. In this paper, a vanadium oxide hydrate (H2V3O8) nanowire membrane is presented as a flexible cathode for SIBs without addition of any other additives (binders or conductive compounds). Such a freestanding flexible membrane exhibits a high specific capacity of 168 mA h g−1 at 10 mA g−1, and its high capacity is maintained well after 100 cycles. It is found that the capacitive charge storage accounts for a relatively large proportion of the total capacity, whereas the crystal structure of H2V3O8 is highly reversible during the sodiation/desodiation processes. This research demonstrates that the H2V3O8 nanowire is an exceptional candidate for SIBs.
Co-reporter:Chao Lin, Chaojiang Niu, Xu Xu, Ke Li, Zhengyang Cai, Yonglai Zhang, Xuanpeng Wang, Longbing Qu, Yuxi Xu and Liqiang Mai
Physical Chemistry Chemical Physics 2016 vol. 18(Issue 32) pp:22146-22153
Publication Date(Web):05 Jul 2016
DOI:10.1039/C6CP03624D
Compared with a two dimensional graphene sheet, a three dimensional (3D) graphene sponge has a continuous conductive structure and numerous pores, which are beneficial for sulfur utilization and anchoring. However, strategies for the construction of 3D graphene sponges composited with sulfur nanoparticles (3DGS) are either energy consuming or involve toxic reagents. Herein, a 3DGS is fabricated via a reduction induced self-assembly method, which is simple but facile and scalable. The structural design of this 3DGS promises fast Li+ transport, superior electrolyte absorbability and effective electrochemical redox reactions of sulfur. As a result, this 3DGS achieves a stable capacity of 580 mA h g−1 after 500 cycles at a high rate of 1.5 A g−1, which corresponds to a low fading rate of 0.043% per cycle. The present study effectively demonstrates that the 3D construction strategy is propitious for obtaining flexible high performance Li–S batteries.
Co-reporter:Cong Yin, Liang He, Yunfei Wang, Zehua Liu, Guobin Zhang, Kangning Zhao, Chunjuan Tang, Mengyu Yan, Yulai Han and Liqiang Mai
RSC Advances 2016 vol. 6(Issue 49) pp:43436-43441
Publication Date(Web):25 Apr 2016
DOI:10.1039/C6RA06864B
Photoresist, a frequently used material in existing microfabrication processes, can be utilized in carbon micro electro mechanical system (C-MEMS) since the patterned carbon micro/nano structures can be formed by pyrolysis of a patterned photoresist. These pyrolyzed carbon microstructures have been used as functional and structural units in carbon-MEMS. Compositing and integration with high performance nanostructures is one important strategy for carbon microstructures with applications in microdevices. Herein, we report a patterned microelectrode of pyrolyzed carbon with embedded NiO/Ni nanospheres (carbon/NiO/Ni) fabricated by a novel microfabrication process combing optimized photolithography with pyrolysis. The microsupercapacitors with interdigital carbon/NiO/Ni (C/NiO/Ni) microelectrodes show a high capacitance of 2.75 mF cm−2. In this microsupercapacitor, the C/NiO/Ni is utilized as the active electrode material and current collector, which makes the microfabrication facile and compatible with micromachining technologies. In addition, the C/NiO/Ni microelectrode pyrolyzed at 900 °C shows a higher capacitance than that of pyrolyzed carbon microelectrodes. The optimized microfabrication process with effectiveness and repeatability shows great potential for fine micropatterning of carbon and electrochemically active materials on a large scale, especially for the microstructuring of a carbon-based composite.
Co-reporter:Yang Yu, Chaojiang Niu, Chunhua Han, Kangning Zhao, Jiashen Meng, Xiaoming Xu, Pengfei Zhang, Lei Wang, Yuzhu Wu, and Liqiang Mai
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 11) pp:2992-2999
Publication Date(Web):March 3, 2016
DOI:10.1021/acs.iecr.5b04811
Transition metal vanadates have gradually caputured reseachers’ attention as anode materials for lithium ion batteries, because of their high specific capacity and relatively high chemical stability. However, they suffer from low rate performance and short cycling performance because of the intrinsic low electronic conductivity and large volume variation during lithiation and delithiation. Here we report a design of zinc pyrovanadate nanoplates embedded in graphene networks through a facile one-pot hydrothermal method. Benefiting from graphene and zinc pyrovanadate nanoplates, this nanocomposite possesses high specific capacity, excellent rate capability, and superior cycling stability. Particularly, it exhibits a high reversible capacity of 902 mA h g–1 at 500 mA g–1, maintaining 854 mA h g–1 after 400 cycles. The impressive electrochemical performance makes it a promising anode material for lithium ion batteries.
Co-reporter:Mengyu Yan, Guobin Zhang, Qiulong Wei, Xiaocong Tian, Kangning Zhao, Qinyou An, Liang Zhou, Yunlong Zhao, Chaojiang Niu, Wenhao Ren, Liang He, Liqiang Mai
Nano Energy 2016 Volume 22() pp:406-413
Publication Date(Web):April 2016
DOI:10.1016/j.nanoen.2016.01.031
•Laboratory X-ray source is employed to probe the electrochemical reaction with high time resolution.•For the first time, we demonstrate the existence of intermediate phases during the lithiation/delithiation processes at low temperature.•Such intermediate phases between LiFePO4/FePO4 can efficiently inhibit the degradation of ion diffusion coefficient with decreasing of reaction temperature.LiFePO4 is one of the most outstanding cathodes for the high performance lithium-ion battery, while it is restricted by its unsatisfactory low temperature performance. Here we detect the structural dynamics and reaction routes of LiFePO4 via operando condition with high rates, well reproducibility over cycles and low temperature in common laboratory X-ray without the synchrotron light source. The intermediate phases between LiFePO4 and FePO4, driven by the overpotential and limited ion transfer rate along the b direction at low temperature, are captured. Our results demonstrate that the existence of intermediate can greatly improve the diffusion kinetics of LiFePO4. The deep understanding of reaction routes of LiFePO4 at low temperature will guide the further material optimization design. Besides LiFePO4, such high time resolution in-situ X-ray diffraction testing method with laboratory source is available to understand the reaction mechanisms of other electrochemical reaction system.
Co-reporter:Jinzhi Sheng, Han Zang, Chunjuan Tang, Qinyou An, Qiulong Wei, Guobin Zhang, Lineng Chen, Chen Peng, Liqiang Mai
Nano Energy 2016 Volume 24() pp:130-138
Publication Date(Web):June 2016
DOI:10.1016/j.nanoen.2016.04.021
•The Fe2(MoO4)3 nanoparticles are synthesized by micro-emulsion for the first time.•The Fe2(MoO4)3/graphene composite shows a high capacity of 64.1 mA h g−1 at 100 C.•A solid solution reaction mechanism of Fe2(MoO4)3 is firstly proved by in-situ XRD.Na+ superionic conductor (NASICON) type Fe2(MoO4)3 with capacious ion diffusion tunnels and a flat discharge plateau, is a promising cathode material for sodium ion batteries. However, the sluggish electrochemical kinetics limits its further development due to the poor electron conductivity and long Na+ diffusion path. In this work, a graphene wrapped Fe2(MoO4)3 nanoparticle composite was synthesized via a micro-emulsion method followed by annealing. The composite exhibits ultra-high rate capability (64.1 mA h g−1 at 100 C, better than all the reported works) and good high-rate cycling stability (76% capacity retention after 100 cycles at 10 C). The enhanced electrochemical performances are attributed to the unique composite structure with shortened ion diffusion distance and high electron conductivity. Furthermore, the Na+ insertion/extraction mechanism of the composite is systematically investigated, based on in-situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Our work demonstrates that the graphene wrapped Fe2(MoO4)3 nanoparticle composite has great potential for high-rate sodium ion batteries.
Co-reporter:Muhammad-Sadeeq Balogun, Weitao Qiu, Feiyi Lyu, Yang Luo, Hui Meng, Jiantao Li, Wenjie Mai, Liqiang Mai, Yexiang Tong
Nano Energy 2016 Volume 26() pp:446-455
Publication Date(Web):August 2016
DOI:10.1016/j.nanoen.2016.05.017
•The first time Carbon cloth (CC) will be directly used as anode for flexible LIBs.•An impressive approach was proposed to improve CC surface area from 7 to 97 m2/g.•The porous CC displayed excellent lithium storage capacity over the commercial CC.•All-flexible lithium ion batteries based on the porous CC were assembled.•The device could power different portable devices at the flat and bending positions.Flexible electrode material with high mechanical strength and excellent electrical stability is still a great challenge for the fabrication of highly flexible energy storage devices. Commercial carbon cloth has been long reported as flexible substrate for many electrode materials due to their high mechanical strength and flexibility. However, their application directly as electrode material for flexible lithium ion batteries is yet to be reported. In this paper, commercial carbon cloth was thermally etched and used directly as electrode material in the half-cell and all-flexible full lithium ion batteries. Upon the mass weight and the large diameter of the carbon fiber, the as-prepared free-standing N-doped Porous carbon cloth delivered an initial capacity of 1.75 mA h/cm2 (190 mA h/g) and capacity up to 1.65 mA h/cm2 (168 mA h/g) after long electrochemical cycles in the half-cell. The all-flexible device exhibits a high working potential of 3.4 V, remarkable lithium storage performance and excellent flexibility. It also achieves a maximum volumetric energy density of 43 W h/cm3 at 0.125 mA/cm2 and power density 800 W/cm3 at 5.0 mA/cm2. The excellent performance can be attributed to N-doped porous surfaces, which provide large surface area for more lithium storage.
Co-reporter:Jing Wang, Xiang Zhang, Qiulong Wei, Haiming Lv, Yanlong Tian, Zhongqiu Tong, Xusong Liu, Jian Hao, Huiying Qu, Jiupeng Zhao, Yao Li, Liqiang Mai
Nano Energy 2016 Volume 19() pp:222-233
Publication Date(Web):January 2016
DOI:10.1016/j.nanoen.2015.10.036
•Co3O4@CoMoO4 nanopine forest electrode has been successfully synthesized.•The electrodes are fabricated by a facile hydrothermal method.•The architecture and synergetic effect contribute to excellent capacitive performance.Solid state device shows outstanding properties for supercapacitors.Herein, we develop a supercapacitor electrode composed of 3D self-supported Co3O4@CoMoO4 core–shell architectures directly grown on nickel foam. Co3O4 nanocones are grown vertically on the nickel foam as the core and CoMoO4 nanosheets are further engineered to immobilized on the surface of the nanocones as the shell. The unique architecture take advantage of a large interfacial area, numerous channels for rapid diffusion of electrolyte ions, fast electron transport and the high electrochemical activity from both the Co3O4 and CoMoO4. The electrode exhibits high specific capacitance of 1902 F g−1 at current density of 1 A g−1, good rate capability, and cycling stability with 99% capacitance retention after 5000 cycles. Solid-state asymmetric supercapacitor (Co3O4@CoMoO4//CNTs) and symmetric supercapacitor (Co3O4@CoMoO4//Co3O4@CoMoO4) are fabricated with excellent electrochemical performance. The asymmetric supercapacitor with a maximum voltage of 1.6 V has demonstrated a high energy density of 45.2 W h kg−1, a high power density of 6400 W kg−1 at 37.0 W h kg−1, and outstanding cyclic stability with the capacitance retention of 98.5% after 3000 cycles.A supercapacitor electrode composed of 3D self-supported Co3O4@CoMoO4 core–shell architectures directly grown on nickel foam. The unique architecture take advantage of a large interfacial area, numerous channels for rapid diffusion of electrolyte ions, fast electron transport and the high electrochemical activity. The electrode exhibits high specific capacitance, good rate capability, and cycling stability. Solid-state asymmetric supercapacitor (Co3O4@CoMoO4//CNTs) with a maximum voltage of 1.6 V delivers outstanding cyclic stability, a high energy density of 45.2 W h kg−1 at a power density of 400 W kg−1, and even at a high power density of 6400 W kg−1, the device still has an energy density of 37.0 W h kg−1.
Co-reporter:Luoluo Wang 王洛洛;Zhengyao Hu 胡正耀;Kangning Zhao 赵康宁
Science China Materials 2016 Volume 59( Issue 2) pp:95-103
Publication Date(Web):2016 February
DOI:10.1007/s40843-016-0120-3
Lithium nickel manganese oxide spinel (LiNi0.5Mn1.5O4, LNMO) has attracted much attention as the cathode material for rechargeable lithium-ion batteries due to its high energy density and low cost. However, the short cycle life and poor high-rate capability hinder its commercialization. In this study, we synthesized hollow spherical LNMO built from polyhedral particles. The LNMO hollow structure guarantees sufficient contact with electrolyte and rapid diffusion of lithium ions. To enhance the conductivity, we use carbon nanotubes (CNTs) to modify the surface of the cathode. After CNT modification, the LNMO hollow structure manifests outstanding cycling stability and high-rate capability. It delivers a discharge capacity of 127 mA h g−1 at 5 C, maintaining 104 mA h g−1 after 500 cycles. Even at a high rate of 20 C, a capacity of 121 mA h g−1 can be obtained. The excellent electrochemical performance is ascribed to the unique structure and the enhanced conductivity through CNT modification. It is demonstrated that the CNT-modified hollow spherical LNMO is a promising cathode for lithium ion batteries.本文通过调节烧结温度设计构筑了一种纳米多面体颗粒堆积的中空球状LiNi0.5Mn1.5O4材料, 并进一步通过碳纳米管(CNT)的改性来提高材料的循环性能和高倍率性能. 纳米中空结构不仅减少了锂离子的扩散路径, 也保证了电解液和正极材料的充分接触, 三维网状CNT的 改性提高了材料的电子导电率, 从而明显改善了材料的循环和高倍率性能. 最终得到的LNMO-850/CNT材料在5 C的电流密度下初始容量为 127 mA h g−1, 500次循环后容量保持在104 mA h g−1. 而在20 C的高电流密度下容量仍达到121 mA h g−1, 体现了材料优异的循环和高倍率性能.
Co-reporter:Chaojiang Niu, Xiong Liu, Jiashen Meng, Lin Xu, Mengyu Yan, Xuanpeng Wang, Guobin Zhang, Ziang Liu, Xiaoming Xu, Liqiang Mai
Nano Energy 2016 Volume 27() pp:147-156
Publication Date(Web):September 2016
DOI:10.1016/j.nanoen.2016.06.057
•A series of 3D hierarchical heterogeneous nanostructures are obtained by one-step gradient hydrothermal method.•The synergistic effect between the branched and backbone structure is revealed with time-resolved in situ XRD.•When tested at 5 A g−1, 92% of the initial capacity is maintained after 1000 cycles.Three-dimensional (3D) hierarchical heterostructures have been widely studied for energy storage because of their amazing synergistic effect. However, a detailed characterization how the branched structure affects the backbone structure during electrochemical cycling, and the specific relationship between the backbone and the branched heterogeneous structure (namely synergistic effect) have been rarely revealed. In addition, the controllable synthesis of this system still remains a great challenge. Herein, we developed a one-step gradient hydrothermal method to obtain a series of 3D hierarchical heterogeneous nanostructures, including V2O5/NaV6O15, V2O5/ZnV2O6 and V2O5/CoV2O6, through controlling the sequence of nucleation and growth processes of different structural units in the same precursor. On the basis of time-resolved in situ X-ray diffraction (XRD) characterizations, we clearly elucidated the synergistic effect between the branched and backbone structure. During the synergistic effect, the branched NaV6O15 helps to reduce the potential barrier during lithium-ion insertion/extraction, buffers the impact of crystal-system transformations during the charge/discharge process; the backbone V2O5 is beneficial to increase the charge/discharge capacity, inhibits the self-aggregation of branched NaV6O15 and maintains the stability of 3D structure. Consequently, 3D V2O5/NaV6O15 hierarchical heterogeneous microspheres exhibit the best electrochemical performance than pure V2O5 and V2O5/NaV6O15 physical mixture in lithium-ion batteries (LIBs). When tested at a high rate of 5 A g−1, 92% of the initial capacity can be maintained after 1000 cycles. We believe this method will be in favor of the construction of 3D hierarchical heterostructures and this specific synergistic effect investigated by in situ XRD will be significant for the design of better electrodes.
Co-reporter:Xinyu Ma, Wen Luo, Mengyu Yan, Liang He, Liqiang Mai
Nano Energy 2016 Volume 24() pp:165-188
Publication Date(Web):June 2016
DOI:10.1016/j.nanoen.2016.03.023
•Recent advances of in situ characterization of 1D nanomaterials are summarized.•Various energy storage devices based on 1D nanomaterials are involved.•Significances of developing in situ characterization technologies are discussed.•Development trend of in situ characterization in 1D nanomaterials are presented.One dimensional (1D) nanomaterials, which show tremendous potential in constructing high performance energy storage device, have gained considerable research interests. However the electrochemical reaction mechanism is still elusive. The most challenging issue in energy storage is developing insightful operando probes for the electrochemical processes. Notably, the in situ characterization of 1D nanomaterials is crucial to investigate the structural changes and uncover the intrinsic reasons for the capacity fading. Therefore numerous in situ characterization methods have been developed, such as in situ electron microscopy, X-ray detection techniques, spectroscopic techniques, nuclear magnetic resonance techniques, etc. Recent developments on in situ characterization technologies are summarized in this review. Different energy storage devices are involved, including Li-ion batteries, Na-ion batteries, supercapacitors, Li–air batteries and Li–S batteries. A new type of energy storage device, single nanowire device, has been also emphasized in this article. The reported highlights and developments are further discussed in details according to their reaction mechanisms. Through in situ characterization, no completely reversible volume expansion and phase transformation were observed during the lithiation and delithiation process. More structural/morphological damage and different electrochemical mechanisms were caused by the replace of lithium ions with sodium ions. The electron/hole doping of electric double layer capacitive materials and oxidation state of pseudocapacitive materials were focused. The growth and decomposition process of Li2O2 and polysulfide were also observed. The optimization mechanisms, including coating and doping of high conductivity materials, were proved to increase the electric/ion conductivity and reduce the cracks. The above mentioned results indicated that 1D nanomaterials with continuous ion/electron channels and short diffusion distance for electrolyte ions showed superior structural stability. Finally, the challenges and perspectives of the in situ characterization of 1D nanomaterials during electrochemical processes are emphasized as the conclusion.
Co-reporter:Chang Xu, Yanan Xu, Chunjuan Tang, Qiulong Wei, Jiashen Meng, Lei Huang, Liang Zhou, Guobin Zhang, Liang He, Liqiang Mai
Nano Energy 2016 Volume 28() pp:224-231
Publication Date(Web):October 2016
DOI:10.1016/j.nanoen.2016.08.026
•Carbon-coated NTP mesoporous microflowers are firstly fabricated via a facile method.•The NTP/C-F shows excellent structural stability and fast charge transfer kinetics.•The NTP/C-F manifests outstanding rate capability and cycling stability.NASICON structured NaTi2(PO4)3 with stable and open framework has become a promising electrode material for sodium-ion batteries. However, the intrinsic low electronic conductivity of NaTi2(PO4)3 leads to inferior rate capability and poor active material utilization. Herein, we first report the synthesis of carbon-coated hierarchical NaTi2(PO4)3 mesoporous microflowers (NTP/C-F), via a facile and controllable solvothermal method and subsequent annealing treatment. The unique structural features endow the NTP/C-F with excellent structural stability, enhanced charge transfer kinetics, and suppressed polarization. This architecture exhibits superior sodium storage performance: high initial capacity (125 mA h g−1 at 1 C), outstanding rate capability (95 mA h g−1 at 100 C), and ultra-long cycling stability (capacity retention of 77.3% after 10,000 cycles at 20 C). Time-resolved in-situ X-ray diffraction study reveals a typical two-phase electrochemical reaction with reversible structure change. This work suggests the integration of hierarchical structure and carbon coating provides a promising approach for boosting the electrochemical performances of battery electrode materials.
Co-reporter:Xiaocong Tian;Bei Xiao;Xu Xu;Lin Xu;Zehua Liu;Zhaoyang Wang
Nano Research 2016 Volume 9( Issue 4) pp:1012-1021
Publication Date(Web):2016 April
DOI:10.1007/s12274-016-0989-x
Planar micro-supercapacitors (MSCs) have drawn extensive research attention owing to their unique structural design and size compatibility for microelectronic devices. Graphene has been widely used to improve the performance of microscale electrochemical capacitors. However, investigations of an intrinsic electrochemical mechanism for graphene-based microscale devices are still not sufficient. Here, micro-supercapacitors with various typical architectures are fabricated as models to study the graphene effect, and their electrochemical performance is also evaluated. The results show that ionic accessibility and adsorption are greatly improved after the introduction of the holey graphene intermediate layer. This study provides a new route to understand intrinsic electrochemical behaviors and possesses exciting potential for highly efficient on-chip micro-energy storage.
Co-reporter:Chaojiang Niu;Meng Huang;Peiyao Wang;Jiashen Meng;Xiong Liu
Nano Research 2016 Volume 9( Issue 1) pp:128-138
Publication Date(Web):2016 January
DOI:10.1007/s12274-015-0896-6
Naturally abundant transition metal oxides with high theoretical capacity have attracted more attention than commercial graphite for use as anodes in lithium-ion batteries. Lithium-ion battery electrodes that exhibit excellent electrochemical performance can be efficiently achieved via three-dimensional (3D) architectures decorated with conductive polymers and carbon. As such, we developed 3D carbon-supported amorphous vanadium oxide microspheres and crystalline V2O3 microspheres via a facile solvothermal method. Both samples were assembled with ultrathin nanosheets, which consisted of uniformly distributed vanadium oxides and carbon. The formation processes were clearly revealed through a series of time-dependent experiments. These microspheres have numerous active reaction sites, high electronic conductivity, and excellent structural stability, which are all far superior to those of other lithium-ion battery anodes. More importantly, 95% of the second-cycle discharge capacity was retained after the amorphous microspheres were subjected to 7,000 cycles at a high rate of 2,000 mA/g. The crystalline microspheres also exhibited a high-rate and long-life performance, as evidenced by a 98% retention of the second-cycle discharge capacity after 9,000 cycles at a rate of 2,000 mA/g. Therefore, this facile solvothermal method as well as unique carbon-supported and nanosheet-assembled microspheres have significant potential for the synthesis of and use in, respectively, lithium-ion batteries.
Co-reporter:Wen Luo, Armand Calas, Chunjuan Tang, Feng Li, Liang Zhou, and Liqiang Mai
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 51) pp:
Publication Date(Web):December 1, 2016
DOI:10.1021/acsami.6b11544
Metal chalcogenides have emerged as promising anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Herein, a free-standing membrane based on ultralong Sb2Se3 nanowires has been successfully fabricated via a facile hydrothermal synthesis combined with a subsequent vacuum filtration treatment. The as-achieved free-standing membrane constructed by pure Sb2Se3 nanowires exhibits good flexibility and integrity. Meanwhile, we investigate the lithium and sodium storage behavior of the Sb2Se3 nanowire-based free-standing membrane. When applied as the anode for LIBs, it delivers a reversible capacity of 614 mA h g–1 at 100 mA g–1, maintaining 584 mA h g–1 after 50 cycles. When applied as the anode for SIBs, it delivers a reversible capacity of 360 mA h g–1 at 100 mA g–1, retaining 289 mA h g–1 after 50 cycles. Such difference in electrochemical performance can be attributed to the more complex sodiation process relative to the corresponding lithiation process. This work may provide insight on developing Sb2Se3-based anode materials for high-performance LIBs or SIBs.Keywords: anode; antimony triselenide (Sb2Se3); free-standing membrane; lithium ion battery; nanowire; sodium ion battery;
Co-reporter:Wenhao Ren, Xuhui Yao, Chaojiang Niu, Zhiping Zheng, Kangning Zhao, Qinyou An, Qiulong Wei, Mengyu Yan, Lei Zhang, Liqiang Mai
Nano Energy 2016 Volume 28() pp:216-223
Publication Date(Web):October 2016
DOI:10.1016/j.nanoen.2016.08.010
•Na3V2(PO4)3 and hard carbon have been synthesized by an easily scalable approach and a biomass method , respectively.•Na3V2(PO4)3 cathode exhibits excellent rate and cycling performance for sodium half cells.•Na3V2(PO4)3//hard carbon full cell with suppressed polarization has been successfully fabricated.•The promoted electrical transport behaviors and carrier transmission dynamics lead to the improved performance.The application of sodium-ion batteries (SIBs) is largely depended on the high energy density electrode system since it suffers from intrinsic high voltage of Na (0.33 V vs. Li). To overcome these limitations, we propose a high-voltage sodium-ion full cell via cathodic polarization suppression. NASICON structured Na3V2(PO4)3 (NVP) cathode and poorly-graphitized hard carbon (HC) anode are synthesized as the targeted materials through an easily scalable coprecipitation method and a simple biomass-directed technique, respectively. Through morphologic optimization and carbon decoration, the NVP half cell demonstrates a high output voltage of 3.4 V, ultralong cyclability (over 4000 cycles) and distinguished rate capability (77 mA h g−1 at 150 C), which is attributed to the enhanced electrical transport behaviors and carrier transmission dynamics. When extended to NVP//HC, the overpotential has been successfully restrained, and the full cell exhibits a theoretical average voltage of 3.3 V, which shows substantial increases in the energy density (>20%) compared to bulk and bare NVP based full cell. The prototype design of high-energy and low-cost sodium-ion full cell in this work opens the door for accelerating the development and application of SIBs.The Na3V2(PO4)3//hard carbon sodium-ion full cell with suppressed polarization has been successfully fabricated. The average voltage of full cell reaches up to 3.3 V with enhanced energy density, which is attributed to the promoted electrical transport behaviors and enhanced carrier transmission dynamics.
Co-reporter:Wenhao Ren, Zhiping Zheng, Chang Xu, Chaojiang Niu, Qiulong Wei, Qinyou An, Kangning Zhao, Mengyu Yan, Mingsheng Qin, Liqiang Mai
Nano Energy 2016 Volume 25() pp:145-153
Publication Date(Web):July 2016
DOI:10.1016/j.nanoen.2016.03.018
•3D Na3V2(PO4)3 nanofiber network is prepared by a facile self-sacrificed route.•We propose the self-sacrificed morphological evolution mechanism.•The 3D nanofiber network structure provides enhanced electrical transport behaviors.•Na3V2(PO4)3 exhibits excellent rate and cycling performance for sodium–ion batteries.The morphological optimization of Na3V2(PO4)3 (NVP) material has a great significance for improving the electrochemical performance since NVP suffers from intrinsic low electronic conductivity. For this purpose, a novel 3D NVP nanofiber network is controllably constructed via a facile self-sacrificed template method. Based on time-dependent experiments, an outside-in morphological evolution mechanism from microsphere to 3D nanofiber network is proposed. The as-synthesized material exhibits excellent cyclability (95.9% capacity retention over 1000 cycles at 10 C) and enhanced high-rate performance (94 mA h g−1 at 100 C) for sodium half cell. Notably, when evaluated as full battery (NaTi2(PO4)3 as anode) cathode, it also shows outstanding cycling stability (96.9% capacity retention over 300 cycles at 5 C) and superior rate capability (80 mA h g−1 at 50 C). Such remarkable performance is attributed to the 3D nanofiber network structure, which provides multi-channel ionic diffusion pathway, continuous electronic conduction, and improved structural integrity. This self-sacrificed template strategy presented here can inspire new thought in constructing novel nanofiber/nanowire structures and accelerate the development of high-power sodium–ion batteries.The self-sacrificed morphological evolution process of Na3V2(PO4)3 from microsphere to 3D nanofiber network is systematically investigated. The Na3V2(PO4)3 cathode exhibits superior rate and cycling performance for sodium storage through providing multi-channel diffusion pathways, continuous electron conduction, and improved structural integrity.
Co-reporter:Liang He 何亮;Biao Xiong;Peng Zhou;Wen Luo
Journal of Wuhan University of Technology-Mater. Sci. Ed. 2016 Volume 31( Issue 1) pp:52-57
Publication Date(Web):2016 February
DOI:10.1007/s11595-016-1329-4
The optimized growth conditions for high density germanium (Ge) nanowires and P-doped Ge nanowires on Si (111) substrate were investigated, the phosphorus (P)-doping in Ge nanowires was also characterized. Vapor liquid solid-low pressure chemical vapor deposition (VLS-LPCVD) of Ge nanowires was conducted with different thicknesses of Au film as catalyst, different flow rates of GeH4 as precursor and PH3/Ar as co-flow. The morphologies of the Ge nanowires were characterized by scanning electron microscopy (SEM), the P-doping was verified by micro Raman spectroscopy via measuring the P local vibrational peak (342-345 cm-1) and asymmetric broadening of Ge-Ge vibrational peak (about 300 cm-1), respectively. The characterization results show that 1 nm thickness of Au catalyst is the most suitable condition among thicknesses of 0.1, 1, 5, and 10 nm for the growth of high density Ge nanowires at 300 and 350 °C, and 0.5 sccm is the best flow rate of PH3/Ar to grow high density and large scale P-doped Ge nanowires among flow rates of 0.5, 1 and 2 sccm. The P impurity can be doped into Ge nanowires effectively during LPCVD process at 350 °C.
Co-reporter:Yifan Dong, Shuo Li, Kangning Zhao, Chunhua Han, Wei Chen, Bingliang Wang, Lei Wang, Boan Xu, Qiulong Wei, Lei Zhang, Xu Xu and Liqiang Mai
Energy & Environmental Science 2015 vol. 8(Issue 4) pp:1267-1275
Publication Date(Web):19 Feb 2015
DOI:10.1039/C5EE00036J
We report a facile method to topotactically synthesize Na1.25V3O8 nanowires with a novel hierarchical zigzag structure. The unique morphology can provide an increased electrode–electrolyte contact area and better strain accommodation; also the topotactic intercalation method can improve structure integrity and robustness. The as-synthesized material delivers a capacity of 172.5 mA h g−1 at 100 mA g−1, shows excellent cyclability with a capacity fading of only 0.0138% per cycle at 1 A g−1 for 1000 cycles, and high rate capability as a sodium-ion battery cathode. We propose that the novel morphology as well as intrinsically advantageous structural features can synergistically facilitate the kinetics and stability, resulting in superior electrochemical performance.
Co-reporter:Xiaocong Tian;Mengzhu Shi;Xu Xu;Mengyu Yan;Lin Xu;Aamir Minhas-Khan;Chunhua Han;Liang He
Advanced Materials 2015 Volume 27( Issue 45) pp:7476-7482
Publication Date(Web):
DOI:10.1002/adma.201503567
Co-reporter:Kalele Mulonda Hercule;Qiulong Wei;Owusu Kwadwo Asare;Longbing Qu;Aamir Minhas Khan;Mengyu Yan;Chunhui Du;Wei Chen
Advanced Energy Materials 2015 Volume 5( Issue 10) pp:
Publication Date(Web):
DOI:10.1002/aenm.201500060
Co-reporter:Xuanpeng Wang;Chaojiang Niu;Jiashen Meng;Ping Hu;Xiaoming Xu;Xiujuan Wei;Liang Zhou;Kangning Zhao;Wen Luo;Mengyu Yan
Advanced Energy Materials 2015 Volume 5( Issue 17) pp:
Publication Date(Web):
DOI:10.1002/aenm.201500716
Sodium-ion battery has captured much attention due to the abundant sodium resources and potentially low cost. However, it suffers from poor cycling stability and low diffusion coefficient, which seriously limit its widespread application. Here, K3V2(PO4)3/C bundled nanowires are fabricated usinga facile organic acid-assisted method. With a highly stable framework, nanoporous structure, and conductive carbon coating, the K3V2(PO4)3/C bundled nanowires manifest excellent electrochemical performances in sodium-ion battery. A stable capacity of 119 mAh g−1 can be achieved at 100 mA g−1. Even at a high current density of 2000 mA g−1, 96.0% of the capacity can be retained after 2000 charge–discharge cycles. Comparing with K3V2(PO4)3/C blocks, the K3V2(PO4)3/C bundled nanowires show significantly improved cycling stability. This work provides a facile and effective approach to enhance the electrochemical performance of sodium-ion batteries.
Co-reporter:Qinyou An;Fangyu Xiong;Qiulong Wei;Jinzhi Sheng;Liang He;Dongling Ma;Yan Yao
Advanced Energy Materials 2015 Volume 5( Issue 10) pp:
Publication Date(Web):
DOI:10.1002/aenm.201401963
Na3V2(PO4)3 (NVP) has excellent electrochemical stability and fast ion diffusion coefficient due to the 3D Na+ ion superionic conductor framework, which make it an attractive cathode material for lithium ion batteries (LIBs). However, the electrochemical performance of NVP needs to be further improved for applications in electric vehicles and hybrid electric vehicles. Here, nanoflake-assembled hierarchical NVP/C microflowers are synthesized using a facile method. The structure of as-synthesized materials enhances the electrochemical performance by improving the electron conductivity, increasing electrode–electrolyte contact area, and shortening the diffusion distance. The as-synthesized material exhibits a high capacity (230 mAh g−1), excellent cycling stability (83.6% of the initial capacity is retained after 5000 cycles), and remarkable rate performance (91 C) in hybrid LIBs. Meanwhile, the hybrid LIBs with the structure of NVP || 1 m LiPF6/EC (ethylene carbonate) + DMC (dimethyl carbonate) || NVP and Li4Ti5O12 || 1 m LiPF6/EC + DMC || NVP are assembled and display capacities of 79 and 73 mAh g−1, respectively. The insertion/extraction mechanism of NVP is systematically investigated, based on in situ X-ray diffraction. The superior electrochemical performance, the design of hybrid LIBs, and the insertion/extraction mechanism investigation will have profound implications for developing safe and stable, high-energy, and high-power LIBs.
Co-reporter:Xu Xu, Mengyu Yan, Xiaocong Tian, Chuchu Yang, Mengzhu Shi, Qiulong Wei, Lin Xu, and Liqiang Mai
Nano Letters 2015 Volume 15(Issue 6) pp:3879-3884
Publication Date(Web):May 19, 2015
DOI:10.1021/acs.nanolett.5b00705
In the past decades, Li ion batteries are widely considered to be the most promising rechargeable batteries for the rapid development of mobile devices and electric vehicles. There arouses great interest in Na ion batteries, especially in the field of static grid storage due to their much lower production cost compared with Li ion batteries. However, the fundamental mechanism of Li and Na ion transport in nanoscale electrodes of batteries has been rarely experimentally explored. This insight can guide the development and optimization of high-performance electrode materials. In this work, single nanowire devices with multicontacts are designed to obtain detailed information during the electrochemical reactions. This unique platform is employed to in situ investigate and compare the transport properties of Li and Na ions at a single nanowire level. To give different confinement for ions and electrons during the electrochemical processes, two different configurations of nanowire electrode are proposed; one is to fully immerse the nanowire in the electrolyte, and the other is by using photoresist to cover the nanowire with only one end exposed. For both configurations, the conductivity of nanowire decreases after intercalation/deintercalation for both Li and Na ions, indicating that they share the similar electrochemical reaction mechanisms in layered electrodes. However, the conductivity degradation and structure destruction for Na ions is more severe than those of Li ions during the electrochemical processes, which mainly results from the much larger volume of Na ions and greater energy barrier encountered by the limited layered spaces. Moreover, the battery performances of coin cells are compared to further confirm this conclusion. The present work provides a unique platform for in situ electrochemical and electrical probing, which will push the fundamental and practical research of nanowire electrode materials for energy storage applications.
Co-reporter:Zhengyang Cai, Lin Xu, Mengyu Yan, Chunhua Han, Liang He, Kalele Mulonda Hercule, Chaojiang Niu, Zefan Yuan, Wangwang Xu, Longbing Qu, Kangning Zhao, and Liqiang Mai
Nano Letters 2015 Volume 15(Issue 1) pp:738-744
Publication Date(Web):December 9, 2014
DOI:10.1021/nl504427d
Transition metal oxides have attracted much interest for their high energy density in lithium batteries. However, the fast capacity fading and the low power density still limit their practical implementation. In order to overcome these challenges, one-dimensional yolk–shell nanorods have been successfully constructed using manganese oxide as an example through a facile two-step sol–gel coating method. Dopamine and tetraethoxysilane are used as precursors to obtain uniform polymer coating and silica layer followed by converting into carbon shell and hollow space, respectively. As anode material for lithium batteries, the manganese oxide/carbon yolk–shell nanorod electrode has a reversible capacity of 660 mAh/g for initial cycle at 100 mA/g and exhibits excellent cyclability with a capacity of 634 mAh/g after 900 cycles at a current density of 500 mA/g. An enhanced capacity is observed during the long-term cycling process, which may be attributed to the structural integrity, the stability of solid electrolyte interphase layer, and the electrochemical actuation of the yolk–shell nanorod structure. The results demonstrate that the manganese oxide is well utilized with the one-dimensional yolk–shell structure, which represents an efficient way to realize excellent performance for practical applications.
Co-reporter:Yunlong Zhao, Chunhua Han, Junwei Yang, Jie Su, Xiaoming Xu, Shuo Li, Lin Xu, Ruopian Fang, Hong Jiang, Xiaodong Zou, Bo Song, Liqiang Mai, and Qingjie Zhang
Nano Letters 2015 Volume 15(Issue 3) pp:2180-2185
Publication Date(Web):February 5, 2015
DOI:10.1021/acs.nanolett.5b00284
Intercalation of ions in electrode materials has been explored to improve the rate capability in lithium batteries and supercapacitors, due to the enhanced diffusion of Li+ or electrolyte cations. Here, we describe a synergistic effect between crystal structure and intercalated ion by experimental characterization and ab initio calculations, based on more than 20 nanomaterials: five typical cathode materials together with their alkali metal ion intercalation compounds A–M–O (A = Li, Na, K, Rb; M = V, Mo, Co, Mn, Fe–P). Our focus on nanowires is motivated by general enhancements afforded by nanoscale structures that better sustain lattice distortions associated with charge/discharge cycles. We show that preintercalation of alkali metal ions in V–O and Mo–O yields substantial improvement in the Li ion charge/discharge cycling and rate, compared to A–Co–O, A–Mn–O, and A–Fe–P–O. Diffraction and modeling studies reveal that preintercalation with K and Rb ions yields a more stable interlayer expansion, which prevents destructive collapse of layers and allow Li ions to diffuse more freely. This study demonstrates that appropriate alkali metal ion intercalation in admissible structure can overcome the limitation of cyclability as well as rate capability of cathode materials, besides, the preintercalation strategy provides an effective method to enlarge diffusion channel at the technical level, and more generally, it suggests that the optimized design of stable intercalation compounds could lead to substantial improvements for applications in energy storage.
Co-reporter:Longbing Qu, Yunlong Zhao, Aamir Minhas Khan, Chunhua Han, Kalele Mulonda Hercule, Mengyu Yan, Xingyu Liu, Wei Chen, Dandan Wang, Zhengyang Cai, Wangwang Xu, Kangning Zhao, Xiaolin Zheng, and Liqiang Mai
Nano Letters 2015 Volume 15(Issue 3) pp:2037-2044
Publication Date(Web):February 24, 2015
DOI:10.1021/nl504901p
Development of pseudocapacitor electrode materials with high comprehensive electrochemical performance, such as high capacitance, superior reversibility, excellent stability, and good rate capability at the high mass loading level, still is a tremendous challenge. To our knowledge, few works could successfully achieve the above comprehensive electrochemical performance simultaneously. Here we design and synthesize one interwoven three-dimensional (3D) architecture of cobalt oxide nanobrush-graphene@NixCo2x(OH)6x (CNG@NCH) electrode with high comprehensive electrochemical performance: high specific capacitance (2550 F g–1 and 5.1 F cm–2), good rate capability (82.98% capacitance retention at 20 A g–1 vs 1 A g–1), superior reversibility, and cycling stability (92.70% capacitance retention after 5000 cycles at 20 A g–1), which successfully overcomes the tremendous challenge for pseudocapacitor electrode materials. The asymmetric supercapacitor of CNG@NCH//reduced-graphene-oxide-film exhibits good rate capability (74.85% capacitance retention at 10 A g–1 vs 0.5 A g–1) and high energy density (78.75 Wh kg–1 at a power density of 473 W kg–1). The design of this interwoven 3D frame architecture can offer a new and appropriate idea for obtaining high comprehensive performance electrode materials in the energy storage field.
Co-reporter:Qiulong Wei;Shuangshuang Tan;Xiaoyi Liu;Mengyu Yan;Fengchao Wang;Qidong Li;Qinyou An;Ruimin Sun;Kangning Zhao;Hengan Wu
Advanced Functional Materials 2015 Volume 25( Issue 12) pp:1773-1779
Publication Date(Web):
DOI:10.1002/adfm.201404311
Scroll-shape structures with adjustable space provide interlayer sliding to accommodate the volume changes, which are promising candidates for increasing the stability of lithium batteries (LBs). In this work, for the first time, novel vanadium oxide polygonal nanoscrolls (PNSs) are synthesized in solution through self-rolling, Ostwald ripening, and scroll-by-scroll processes. The PNSs are of various shapes (including triangle, quadrangle, pentagon, and so forth) and spiral-wrapped multiwall. When evaluated as cathode for LB, the vanadium oxide PNSs cathode exhibits largely enhanced cycling stability (capacity retention of 91.7% after 150 cycles at 0.1 A g–1 in 2.0–4.0 V) compared with those of nonscrolled nanobelts (40.0%) and nanowires (35.8%). Even at 1.0 A g–1, the PNSs cathode delivers high-rate long-life performance with capacity retention of 80.6% after 500 cycles. The unique polygonal nanoscroll structure is favorable for improving the cyclability and rate capability in energy storage applications as demonstrated here, and it will be interesting and has great potential for other related applications.
Co-reporter:Chunjuan Tang, Jinzhi Sheng, Chang Xu, S. M. B. Khajehbashi, Xuanpeng Wang, Ping Hu, Xiujuan Wei, Qiulong Wei, Liang Zhou and Liqiang Mai
Journal of Materials Chemistry A 2015 vol. 3(Issue 38) pp:19427-19432
Publication Date(Web):10 Aug 2015
DOI:10.1039/C5TA04680G
Layered silicate is a new type of electrode material with high reversible capacity. However, its poor electrical conductivity leads to rapid capacity decay. To solve this problem, reduced graphene oxide (RGO) wrapped nickel silicate (NiSiO) hollow spheres are successfully synthesized. The hollow structure provides sufficient free space to accommodate the volume variation during lithiation/de-lithiation and the RGO improves the electrical conductivity. The resulting NiSiO/RGO delivers a capacity of 400 mA h g−1 at 500 mA g−1 after 1000 cycles, making the NiSiO/RGO composite a promising anode material for lithium-ion batteries.
Co-reporter:Wenhao Ren, Zhiping Zheng, Yanzhu Luo, Wei Chen, Chaojiang Niu, Kangning Zhao, Mengyu Yan, Lei Zhang, Jiashen Meng and Liqiang Mai
Journal of Materials Chemistry A 2015 vol. 3(Issue 39) pp:19850-19856
Publication Date(Web):17 Aug 2015
DOI:10.1039/C5TA04643B
Structural and morphological control of the LiV3O8 material has a significant impact on its electrochemical performance. In order to obtain a favorable structure, a hierarchical LiV3O8 nanowire-in-network is designed and constructed by electrospinning through a polymer crosslinking strategy. The crosslinking effect between poly(vinyl alcohol) (PVA) and poly(ethylene oxide) (PEO) not only benefits electrospinning, but also realizes a mild multi-step degradation process during calcination. Based on temperature-dependent experiments and thermogravimetric (TG) analysis, the function of polymer blends and the formation mechanism of the structure are discussed in detail. As a cathode for lithium batteries, LiV3O8 exhibits a high initial capacity of 320.6 mA h g−1 at 100 mA g−1 and a high-rate capacity of 202.8 mA h g−1 at 2000 mA g−1. This remarkable performance is attributed to its unique structure, which provides a large effective contact area, low charge transfer resistance, and improved structural stability. Our work indicates that the hierarchical LiV3O8 nanowire-in-network material is a promising cathode for use in high-rate and long-life rechargeable lithium batteries.
Co-reporter:Qiulong Wei, Jin Liu, Wei Feng, Jinzhi Sheng, Xiaocong Tian, Liang He, Qinyou An and Liqiang Mai
Journal of Materials Chemistry A 2015 vol. 3(Issue 15) pp:8070-8075
Publication Date(Web):02 Mar 2015
DOI:10.1039/C5TA00502G
Sodium ion batteries (SIBs), as potential candidates for large-scale energy storage systems, have attracted great attention from researchers. Herein, a V2O5·nH2O xerogel composed of thin acicular interconnected nanowire networks has been synthesized via a facile freeze-drying process. The interlayer spacing of V2O5·nH2O is larger than that of orthorhombic V2O5 due to the intercalation of water molecules into the layer structure. As the cathode of a SIB, V2O5·nH2O exhibits a high initial capacity of 338 mA h g−1 at 0.05 A g−1 and a high-rate capacity of 96 mA h g−1 at 1.0 A g−1. On the basis of combining ex-situ XRD and FTIR spectroscopy, the Na+ ion intercalation storage reactions are discussed in detail. By modeling calculations, the pseudocapacitive behavior makes a great contribution to the high capacities. Our work demonstrates that V2O5·nH2O with large interlayer spacing is a promising candidate for high capacity sodium-based energy storage.
Co-reporter:Qidong Li, Qiulong Wei, Qinqin Wang, Wen Luo, Qinyou An, Yanan Xu, Chaojiang Niu, Chunjuan Tang and Liqiang Mai
Journal of Materials Chemistry A 2015 vol. 3(Issue 37) pp:18839-18842
Publication Date(Web):2015/08/18
DOI:10.1039/C5TA05594F
A hollow shell-controlled Li3VO4 is fabricated via a facile self-template method, which has a controllable shell thickness in the range of 10–300 nm. This hollow shell-controlled Li3VO4 composited with reduced graphene oxide exhibits excellent rate capability (201 mA h g−1 at 125 C) and superior high-temperature stability (364.2 mA h g−1 after 1000 cycles at 10 C, 60 °C).
Co-reporter:Xiujuan Wei, Chunjuan Tang, Xuanpeng Wang, Liang Zhou, Qiulong Wei, Mengyu Yan, Jinzhi Sheng, Ping Hu, Bolun Wang, and Liqiang Mai
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 48) pp:26572
Publication Date(Web):November 13, 2015
DOI:10.1021/acsami.5b07863
Hierarchical copper silicate hydrate hollow spheres-reduced graphene oxide (RGO) composite is successfully fabricated by a facile hydrothermal method using silica as in situ sacrificing template. The electrochemical performance of the composite as lithium-ion battery anode was studied for the first time. Benefiting from the synergistic effect of the hierarchical hollow structure and conductive RGO matrix, the composite exhibits excellent long-life performance and rate capability. A capacity of 890 mAh/g is achieved after 200 cycles at 200 mA/g and a capacity of 429 mAh/g is retained after 800 cycles at 1000 mA/g. The results indicate that the strategy of combining hierarchical hollow structures with conductive RGO holds the potential in addressing the volume expansion issue of high capacity anode materials.Keywords: copper silicate hydrate; hierarchical hollow spheres; lithium-ion battery; long cycling performance; reduced graphene oxide
Co-reporter:Fangyu Xiong, Zhengyang Cai, Longbing Qu, Pengfei Zhang, Zefang Yuan, Owusu Kwadwo Asare, Wangwang Xu, Chao Lin, and Liqiang Mai
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 23) pp:12625
Publication Date(Web):June 3, 2015
DOI:10.1021/acsami.5b02978
Recently, layered transition-metal dichalcogenides (TMDs) have gained great attention for their analogous graphite structure and high theoretical capacity. However, it has suffered from rapid capacity fading. Herein, we present the crumpled reduced graphene oxide (RGO) decorated MoS2 nanoflowers on carbon fiber cloth. The three-dimensional framework of interconnected crumpled RGO and carbon fibers provides good electronic conductivity and facile strain release during electrochemical reaction, which is in favor of the cycling stability of MoS2. The crumpled RGO decorated MoS2 nanoflowers anode exhibits high specific capacity (1225 mAh/g) and excellent cycling performance (680 mAh/g after 250 cycles). Our results demonstrate that the three-dimensional crumpled RGO/MoS2 nanoflowers anode is one of the attractive anodes for lithium-ion batteries.Keywords: crumpled reduced graphene oxide; lithium-ion battery; MoS2; nanoflower; stable anode;
Co-reporter:Yanzhu Luo, Xu Xu, Yuxiang Zhang, Yuqiang Pi, Mengyu Yan, Qiulong Wei, Xiaocong Tian, and Liqiang Mai
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 31) pp:17527
Publication Date(Web):July 21, 2015
DOI:10.1021/acsami.5b05451
Olivine-type LiMnPO4 has been extensively studied as a high-energy density cathode material for lithium-ion batteries. To improve both the ionic and electronic conductivities of LiMnPO4, a series of carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposites are synthesized by a facile sol–gel method combined with the conventional solid-state method. The optimized composite presents a three-dimensional hierarchical structure with active nanoparticles well-embedded in a conductive carbon matrix. The combination of the nanoscale carbon coating and the microscale carbon network could provide a more active site for electrochemical reaction, as well as a highly conductive network for both electron and lithium-ion transportation. When cycled at 20 C, an initial specific capacity of 103 mA h g–1 can be obtained and the capacity retention reaches 68% after 3000 cycles, corresponding to a capacity fading of 0.013% per cycle. The stable capacity and excellent rate capability make this carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposite a promising cathode for lithium-ion batteries.Keywords: high rate; lithium-ion diffusion; lithium−manganese phosphate; lithium−vanadium phosphate; long life
Co-reporter:Qiulong Wei, Zhouyang Jiang, Shuangshuang Tan, Qidong Li, Lei Huang, Mengyu Yan, Liang Zhou, Qinyou An, and Liqiang Mai
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 33) pp:18211
Publication Date(Web):August 10, 2015
DOI:10.1021/acsami.5b06154
Operating as the “rocking-chair” battery, sodium ion battery (SIB) with acceptable high capacity is a very promising energy storage technology. Layered vanadium oxide xerogel exhibits high sodium storage capacity. But it undergoes large lattice breathing during sodiation/desodiation, resulting in fast capacity fading. Herein, we develop a facile hydrothermal method to synthesize iron preintercalated vanadium oxide ultrathin nanobelts (Fe-VOx) with constricted interlayer spacing. Using the Fe-VOx as cathode for SIB, the lattice breathing during sodiation/desodiation is largely inhibited and the interlayer spacing is stabilized for reversible and rapid Na+ insertion/extraction, displaying enhanced cycling and rate performance. This work presents a new strategy to reduce the lattice breathing of layered materials for enhanced sodium storage through interlayer spacing engineering.Keywords: lattice breathing; layered structure; nanobelt; sodium ion battery; vanadium oxide
Co-reporter:Ruimin Sun, Qiulong Wei, Qidong Li, Wen Luo, Qinyou An, Jinzhi Sheng, Di Wang, Wei Chen, and Liqiang Mai
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 37) pp:20902
Publication Date(Web):September 2, 2015
DOI:10.1021/acsami.5b06385
As an alternative system of rechargeable lithium ion batteries, sodium ion batteries revitalize researchers’ interest due to the low cost, abundant sodium resources, and similar storage mechanism to lithium ion batteries. VS4 has emerged as a promising anode material for SIBs due to low cost and its unique linear chains structure that can offer potential sites for sodium storage. Herein, we present the growth of VS4 on reduced graphene oxide (rGO) as SIBs anode for the first time. The VS4/rGO anode exhibits promising performance in SIBs. It delivers a reversible capacity of 362 mAh g–1 at 100 mA g–1 and a good rate performance. We also investigate the sodium storage behavior of the VS4/rGO. Different than most transition metal sulfides, the VS4/rGO composite experiences a three-step separation mechanism during the sodiation process (VS4 to metallic V and Na2S, then the electrochemical mechanism is akin to Na–S). The VS4/rGO composite proves to be a promising material for rechargeable SIBs.Keywords: anode; energy storage; reduced graphene oxide; sodium ion battery; VS4
Co-reporter:Kangning Zhao;Fengning Liu;Chaojiang Niu;Wangwang Xu;Yifan Dong;Lei Zhang;Shaomei Xie;Mengyu Yan;Qiulong Wei;Dongyuan Zhao
Advanced Science 2015 Volume 2( Issue 12) pp:
Publication Date(Web):
DOI:10.1002/advs.201500154
Co-reporter:Qidong Li;Qiulong Wei;Jinzhi Sheng;Mengyu Yan;Liang Zhou;Wen Luo;Ruimin Sun
Advanced Science 2015 Volume 2( Issue 12) pp:
Publication Date(Web):
DOI:10.1002/advs.201500284
Despite the enormous efforts devoted to high-performance lithium-ion batteries (LIBs), the present state-of-the-art LIBs cannot meet the ever-increasing demands. With high theoretical capacity, fast ionic conductivity, and suitable charge/discharge plateaus, Li3VO4 shows great potential as the anode material for LIBs. However, it suffers from poor electronic conductivity. In this work, we present a novel composite material with mesoporous Li3VO4/C submicron-ellipsoids supported on rGO (LVO/C/rGO). The synthesized LVO/C/rGO exhibits a high reversible capacity (410 mAh g−1 at 0.25 C), excellent rate capability (230 mAh g−1 at 125 C), and outstanding long-cycle performance (82.5% capacity retention for 5000 cycles at 10 C). The impressive electrochemical performance reveals the great potential of the mesoporous LVO/C/rGO as a practical anode for high-power LIBs.
Co-reporter:Lei Zhang, Kangning Zhao, Wangwang Xu, Yifan Dong, Rui Xia, Fengning Liu, Liang He, Qiulong Wei, Mengyu Yan and Liqiang Mai
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 12) pp:7619-7623
Publication Date(Web):10 Feb 2015
DOI:10.1039/C5CP00150A
Conversion/alloying reactions, in which more lithium ions are involved, are severely handicapped by the dramatic volume changes. A facile and versatile strategy has been developed for integrating the SnO2 nanorod array in the PPy nanofilm for providing a flexible confinement for anchoring each nanorod and maintaining the entire structural integrity and providing sustainable contact; therefore, exhibiting much more stable cycling stability (701 mA h g−1 after 300 cycles) and better high-rate capability (512 mA h g−1 at 3 A g−1) when compared with the core–shell SnO2–PPy NA.
Co-reporter:Jiangfeng Ni, Yang Zhao, Liang Li, Liqiang Mai
Nano Energy 2015 Volume 11() pp:129-135
Publication Date(Web):January 2015
DOI:10.1016/j.nanoen.2014.10.027
•Ultrathin MoO2/C nanosheets were fabricated through a two-step process involving interfacial self-assembly and thermal reduction.•The MoO2 nanosheets consist of 3–10 layers with thickness of only 2–7 nm.•The MoO2/C nanosheets retain 1051 mAh g−1 over 100 cycles at a rate of 0.5 A g−1.•The MoO2/C nanosheets also exhibit robust rate capability, thereby suggesting their great potential for high power battery applications.Ultrathin MoO2 nanosheets encapsulated in carbon matrix were fabricated through a facile interfacial self-assembly of laminar MoO3 nanosheets, followed by thermal reduction to MoO2 mediated by glucose. The resulting MoO2/C nanosheets exhibited a superior Li-storage capacity, retaining 1051 mAh g−1 over 100 cycles at a rate of 0.5 A g−1, and 719 mAh g−1 over another 100 cycles at a high rate of 5 A g−1 (based on the total mass of MoO2 and carbon). More importantly, the MoO2/C nanosheets exhibit robust rate capability, affording a stable capacity of 544 mAh g−1 at an extremely high rate of 10 A g−1, thereby suggesting their great potential as promising electrode materials for high power battery applications such as electric automobiles and power tools.Carbon encapsulated ultrathin MoO2 nanosheets exhibited a superior Li-storage capability, thereby suggesting their great potential as promising electrode materials for high power battery applications.
Co-reporter:Liyuan Chai, Jiexi Wang, Haiying Wang, Liyuan Zhang, Wanting Yu, Liqiang Mai
Nano Energy 2015 Volume 17() pp:224-232
Publication Date(Web):October 2015
DOI:10.1016/j.nanoen.2015.09.001
•Filamentous fungus is a carbonizable binder to build a graphene-embedded carbon film.•Carbon film is porous and doped by N and O element with conductivity 0.71 S/cm.•With inserting carbon film, Li–S batteries deliver capacity of ~700 mAh g−1 at 5 C.Graphene-embedded carbon fiber (GFC) film has been fabricated by using filamentous fungus (Aspergillus niger) as carbonizable fibers to drive the graphene nanosheets to embed in the hyphae network system and then carbonizing at 700 °C. The molecular structure of the GFC film is primarily composed of aromatic components, and the film is doped by N (8.62%) and O (8.12%) elements. The conductivity of the final product reaches as high as 0.71 S cm−1. The GFC film serves as the conductive interlayer to greatly improve the performance of Li–S batteries including capacity retention and rate capability. By inserting the GFC film, the battery can deliver a capacity of ~700 mAh g−1 after 300 cycles at 1 C. Even performed at 5 C, it is able to deliver a reversible capacity of more than 650 mAh g−1. This research presents a facile and effective method for the fabrication of superior macroscopic carbon monolith, which holds great potential in other forms of electrochemical energy storage.
Co-reporter:Yifan Dong, Xiaoming Xu, Shuo Li, Chunhua Han, Kangning Zhao, Lei Zhang, Chaojiang Niu, Zhe Huang, Liqiang Mai
Nano Energy 2015 Volume 15() pp:145-152
Publication Date(Web):July 2015
DOI:10.1016/j.nanoen.2015.04.015
•The Na+ pre-intercalated MoO3 nanobelts were designed and successfully prepared via a facile method, and the Na+ intercalation amount can be well controlled.•Compared to pristine MoO3, the Na+ pre-intercalated nanobelts exhibit significant improvement in cycling stability as well as rate capability.•Through in-situ XRD analyses combined with the electrochemical tests, it is demonstrated that Na+ pre-intercalation can effectively inhibit the irreversible structure change of the MoO3 nanobelts.Layered molybdenum trioxide (α-MoO3) has been widely investigated as a promising Li battery cathode material. However, its low conductivity and irreversible structure change during charge–discharge process leads to its poor electrochemical performance. Although several methods have been reported to increase its conductivity, the issue of structure degradation still hinders its practical application. Here, a Na+ pre-intercalation strategy was proposed. The Na ions were successfully pre-intercalated into MoO3 nanobelts via a facile method, and the intercalation amount can be well controlled. Compared to pristine MoO3, the Na+ pre-intercalated nanobelts exhibit significant improvement in cycling stability as well as rate capability. Through in-situ XRD analyses combined with the electrochemical tests, it is demonstrated that the Na ions between the Mo–O interlayers effectively inhibit the irreversible phase transition and stabilize the layered structure. The inhibiting effect and the proposed Na+ pre-intercalation strategy are fundamentally important to further promote the development of molybdenum based or other layered electrode materials.
Co-reporter:Qinyou An, Yifei Li, Hyun Deog Yoo, Shuo Chen, Qiang Ru, Liqiang Mai, Yan Yao
Nano Energy 2015 Volume 18() pp:265-272
Publication Date(Web):November 2015
DOI:10.1016/j.nanoen.2015.10.029
•Graphene decorated hydrated vanadium oxide as a high capacity Mg2+ cathode.•Broad temperature window from −30 °C to 55 °C.•Charge shielding effect of crystal water enhances the Mg2+ insertion kinetics.We report graphene decorated hydrated vanadium oxide nanocomposite as an effective cathode material for long cycle-life Mg storage. Excellent electrochemical performance with specific capacity of 330 mAh g−1 at low rate and stable cycling of 200 cycles with 81% capacity retention at 1 A g−1 was reported. Furthermore, the nanocomposite cathode shows a broad working temperature window from −30 °C to 55 °C with over 200 mAh g−1 capacity at 55 °C (1.0 A g−1). The charge shielding effect of crystal water in the aerogel enhances the Mg2+ insertion kinetics and the porous structure of aerogel allows easy access of electrolyte into the active material. The cycling performance, rate performance and broad temperature adaptability demonstrate that the graphene decorated vanadium oxide nanowire aerogel is a promising and attractive cathode material for practical Mg batteries.
Co-reporter:Qinyou An;Pengfei Zhang;Fangyu Xiong;Qiulong Wei;Jinzhi Sheng
Nano Research 2015 Volume 8( Issue 2) pp:481-490
Publication Date(Web):2015 February
DOI:10.1007/s12274-014-0638-1
Three-dimensional (3D) porous V2O5 octahedrons have been successfully fabricated via a solid-state conversion process of freshly prepared ammonium vanadium oxide (AVO) octahedrons. The formation of AVO octahedrons is a result of the selective adsorption of capping reagents and the favourable supersaturation of growth species. Subsequently, 3D porous V2O5 octahedrons were obtained by simple thermolysis of the AVO octahedrons via a calcination treatment. As cathode material for lithium batteries, the porous V2O5 octahedron cathode exhibits a capacity of 96 mA·g−1 at high rate up to 2 A·g−1 in the rang of 2.4–4 V and excellent cyclability with little capacity loss after 500 cycles, which can be ascribed to its high specific surface area and tunable pore architecture. Importantly, this facile solid-state thermal conversion strategy can be easily extended to controllably fabricate other porous metal oxide micro/nano materials with specific surface textures and morphologies.
Co-reporter:Jiexi Wang, Qiaobao Zhang, Xinhai Li, Bao Zhang, Liqiang Mai, Kaili Zhang
Nano Energy 2015 Volume 12() pp:437-446
Publication Date(Web):March 2015
DOI:10.1016/j.nanoen.2015.01.003
•A series of 3D hierarchical tubular transition metal oxides (TMOs) core/shell heterostructure is successfully constructed.•They are demonstrated as binder- and conductive agent-free anode for high-performance lithium ion batteries (LIBs).•For tubular CuO/CoO core/shell arrays anode, a remarkable capacity of 1364 mAh g−1 after 50 cycles and 1140 mAh g−1 even after 1000 cycles at 0.1 A g−1 and 1 A g−1 is achieved, respectively.•Stable structure, good mechanical integrity and 3D ionic and electronic conductive passways all together contribute to their superior electrochemical performance.In order to realize new high performance electrodes for lithium-ion batteries (LIBs), the careful design of nanoarchitectures and effective hybridization of active materials are research areas of great interest. Here, we present a simple and highly controllable two-step fabrication technique, followed by a heat treatment process, for the large-scale in situ growth of 3D hierarchical tubular CuO/other metal oxides core/shell heterostructure arrays that are directly grown on Cu foam. As a proof-of-concept demonstration of the application of such 3D hierarchical tubular heterostructure arrays, the prepared tubular CuO/CoO core/shell arrays are investigated as binder- and conductive agent-free anodes for LIBs, exhibiting an impressive capacity of 1364 mAh g−1 at a current density of 100 mA g−1 after 50 cycles and maintaining 1140 mAh g−1 after 1000 cycles at 1.0 A g−1. This excellent electrochemical performance can be attributed to the unique hollow porous architecture consisting of 3D hierarchical tubular core/shell architectures, and the effective hybridization of two electrochemically cohesive active materials. Our work shows that this material has great potential for high-energy and high-power energy storage applications.
Co-reporter:Liqiang Mai, Xiaocong Tian, Xu Xu, Liang Chang, and Lin Xu
Chemical Reviews 2014 Volume 114(Issue 23) pp:11828
Publication Date(Web):October 7, 2014
DOI:10.1021/cr500177a
Co-reporter:Shuo Li;Yifan Dong;Lin Xu;Xu Xu;Liang He
Advanced Materials 2014 Volume 26( Issue 21) pp:3545-3553
Publication Date(Web):
DOI:10.1002/adma.201305522
Co-reporter:Yanzhu Luo;Xu Xu;Yuxiang Zhang;Yuqiang Pi;Yunlong Zhao;Xiaocong Tian;Qinyou An;Qiulong Wei
Advanced Energy Materials 2014 Volume 4( Issue 16) pp:
Publication Date(Web):
DOI:10.1002/aenm.201400107
Developing rechargeable lithium ion batteries with fast charge/discharge rate, high capacity and power, long lifespan, and broad temperature adaptability is still a significant challenge. In order to realize the fast and efficient transport of ions and electrons during the charging/discharging process, a 3D hierarchical carbon-decorated Li3V2(PO4)3 is designed and synthesized with a nanoscale amorphous carbon coating and a microscale carbon network. The Brunauer–Emmett–Teller (BET) surface area is 65.4 m2 g−1 and the porosity allows for easy access of the electrolyte to the active material. A specific capacity of 121 mAh g−1 (91% of the theoretical capacity) can be obtained at a rate up to 30 C. When cycled at a rate of 20 C, the capacity retention is 77% after 4000 cycles, corresponding to a capacity fading of 0.0065% per cycle. More importantly, the composite cathode shows excellent temperature adaptability. The specific discharge capacities can reach 130 mAh g−1 at 20 C and 60 °C, and 106 mAh g−1 at 5 C and –20 °C. The rate performance and broad temperature adaptability demonstrate that this hierarchical carbon-decorated Li3V2(PO4)3 is one of the most attractive cathodes for practical applications.
Co-reporter:Qinyou An, Fan Lv, Qiuqi Liu, Chunhua Han, Kangning Zhao, Jinzhi Sheng, Qiulong Wei, Mengyu Yan, and Liqiang Mai
Nano Letters 2014 Volume 14(Issue 11) pp:6250-6256
Publication Date(Web):October 14, 2014
DOI:10.1021/nl5025694
Developing electrode materials with both high energy and power densities holds the key for satisfying the urgent demand of energy storage worldwide. In order to realize the fast and efficient transport of ions/electrons and the stable structure during the charge/discharge process, hierarchical porous Fe3O4/graphene nanowires supported by amorphous vanadium oxide matrixes have been rationally synthesized through a facile phase separation process. The porous structure is directly in situ constructed from the FeVO4·1.1H2O@graphene nanowires along with the crystallization of Fe3O4 and the amorphization of vanadium oxide without using any hard templates. The hierarchical porous Fe3O4/VOx/graphene nanowires exhibit a high Coulombic efficiency and outstanding reversible specific capacity (1146 mAh g–1). Even at the high current density of 5 A g–1, the porous nanowires maintain a reversible capacity of ∼500 mAh g–1. Moreover, the amorphization and conversion reactions between Fe and Fe3O4 of the hierarchical porous Fe3O4/VOx/graphene nanowires were also investigated by in situ X-ray diffraction and X-ray photoelectron spectroscopy. Our work demonstrates that the amorphous vanadium oxides matrixes supporting hierarchical porous Fe3O4/graphene nanowires are one of the most attractive anodes in energy storage applications.
Co-reporter:Qiulong Wei, Qinyou An, Dandan Chen, Liqiang Mai, Shiyu Chen, Yunlong Zhao, Kalele Mulonda Hercule, Lin Xu, Aamir Minhas-Khan, and Qingjie Zhang
Nano Letters 2014 Volume 14(Issue 2) pp:1042-1048
Publication Date(Web):January 17, 2014
DOI:10.1021/nl404709b
Lithium-ion batteries have attracted enormous attention for large-scale and sustainable energy storage applications. Here we present a design of hierarchical Li3V2(PO4)3/C mesoporous nanowires via one-pot synthesis process. The mesoporous structure is directly in situ carbonized from the surfactants (CTAB and oxalic acid) along with the crystallization of Li3V2(PO4)3 without using any hard templates. As a cathode for lithium-ion battery, the Li3V2(PO4)3/C mesoporous nanowires exhibit outstanding high-rate and ultralong-life performance with capacity retention of 80.0% after 3000 cycles at 5 C in 3–4.3 V. Even at 10 C, it still delivers 88.0% of its theoretical capacity. The ability to provide this level of performance is attributed to the hierarchical mesoporous nanowires with bicontinuous electron/ion pathways, large electrode–electrolyte contact area, low charge transfer resistance, and robust structure stability upon prolonged cycling. Our work demonstrates that the unique mesoporous nanowires structure is favorable for improving the cyclability and rate capability in energy storage applications.
Co-reporter:Qidong Li, Jinzhi Sheng, Qiulong Wei, Qinyou An, Xiujuan Wei, Pengfei Zhang and Liqiang Mai
Nanoscale 2014 vol. 6(Issue 19) pp:11072-11077
Publication Date(Web):05 Aug 2014
DOI:10.1039/C4NR03119A
A unique hollow Li3VO4/CNT composite is synthesized via a facile method as an anode material in lithium batteries. Our work opens up the way for a promising material with high rate capability and good cycling stability due to its efficient Li+ diffusion and relatively high structure stability.
Co-reporter:Dandan Wang, Yunlong Zhao, Xu Xu, Kalele Mulonda Hercule, Mengyu Yan, Qinyou An, Xiaocong Tian, Jiaming Xu, Longbing Qu and Liqiang Mai
Nanoscale 2014 vol. 6(Issue 14) pp:8124-8129
Publication Date(Web):22 May 2014
DOI:10.1039/C4NR01941E
Anode materials which undergo a conversion reaction can achieve larger specific capacities than conventional carbon-based materials. They can even achieve higher energy densities when used at low voltages. However, the large amounts of Li2O generated in the interior of these structures when Li ions are inserted can cause volume expansion and mechanical fracturing from the inside out. This leads to a poor cycling performance and limits their commercial application. To overcome this limitation, we introduced Li ions into the interior of the cells of manganese oxide materials and successfully synthesized a novel Li-rich anode material (Li2MnO3). The reversible capacity reached 1279 mA h g−1 after 500 cycles, much higher than that of pure MnO2 or other commercial anodes. This optimization of the internal Li-enrichment and its application in Li2MnO3 nanowires used as low voltage anodes in Li-ion batteries have rarely been reported. Further investigations by X-ray diffraction and photoelectron spectroscopy suggested that the strategy of optimizing the internal Li-enrichment of this novel Li2MnO3 anode is a promising development for Li-ion batteries.
Co-reporter:Qinyou An, Pengfei Zhang, Qiulong Wei, Liang He, Fangyu Xiong, Jinzhi Sheng, Qinqin Wang and Liqiang Mai
Journal of Materials Chemistry A 2014 vol. 2(Issue 10) pp:3297-3302
Publication Date(Web):12 Dec 2013
DOI:10.1039/C3TA14818A
Three-dimensional porous V2O5 hierarchical microplates have been fabricated by a one-step top-down strategy, and display an excellent rate capability and stable capacity of 110 mA h g−1 at 2000 mA g−1 after 100 cycles. We have demonstrated that the facile approach of a solid-phase conversion is promising for large-scale fabrication of highly porous micro/nano materials.
Co-reporter:Xiaocong Tian, Xu Xu, Liang He, Qiulong Wei, Mengyu Yan, Lin Xu, Yunlong Zhao, Chuchu Yang, Liqiang Mai
Journal of Power Sources 2014 Volume 255() pp:235-241
Publication Date(Web):1 June 2014
DOI:10.1016/j.jpowsour.2014.01.017
•The ultrathin pre-lithiated V6O13 nanosheets with 4 nm thickness are prepared.•The smallest electrochemical devices based on nanosheet cathodes are fabricated.•Intrinsic electrical conductivity change is in situ investigated at single nanosheet level.•The as-synthesized material delivers a high initial discharge capacity of 331 mAh g−1.•The high capacity retention of 98% is achieved after 150 cycles.The novel ultrathin pre-lithiated V6O13 nanosheets are prepared through a low-temperature exfoliation in argon followed by a secondary hydrothermal lithiation. The smallest electrochemical devices based on nanosheet cathodes are fabricated to in situ probe the intrinsic advantages of pre-lithiated nanosheets. Pre-lithiated nanosheets show one order of magnitude higher in electrical conductivity compared with non-lithiated nanosheets. The conductance of ultrathin pre-lithiated V6O13 nanosheets still remains at the same level after discharge process while that of ultrathin non-lithiated nanosheets decreases over two orders of magnitude. The electrochemical performances of nanosheet cathodes before and after pre-lithiation are compared to further demonstrate the enhancement of the pre-lithiation. Ultrathin pre-lithiated V6O13 nanosheet cathodes exhibit a high discharge capacity of 301 mAh g−1 at the current density of 100 mA g−1. At a higher current density of 1000 mA g−1, the capacity retention after 150 cycles of ultrathin V6O13 nanosheet cathodes is greatly improved from 46% to 98% after pre-lithiation. The enhanced electrical conductance, excellent discharge capacities and cycling performance demonstrate the great potential of ultrathin pre-lithiated V6O13 nanosheets in next-generation high-performance energy storage applications.
Co-reporter:Xiujuan Wei, Qinyou An, Qiulong Wei, Mengyu Yan, Xuanpeng Wang, Qidong Li, Pengfei Zhang, Bolun Wang and Liqiang Mai
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 35) pp:18680-18685
Publication Date(Web):24 Jul 2014
DOI:10.1039/C4CP02762K
Bowknot-like RuO2 quantum dots@V2O5 nanomaterials have been synthesized by a facile hydrothermal method followed by annealing treatment, which exhibit largely enhanced electrochemical performance. Especially, the RuO2 quantum dots@V2O5 cathode delivers 160 mA h g−1 at 1000 mA g−1 after 100 cycles, which is much higher than 86 mA h g−1 of the pure V2O5 cathode.
Co-reporter:Qinyou An, Jinzhi Sheng, Xu Xu, Qiulong Wei, Yaqin Zhu, Chunhua Han, Chaojiang Niu and Liqiang Mai
New Journal of Chemistry 2014 vol. 38(Issue 5) pp:2075-2080
Publication Date(Web):05 Dec 2013
DOI:10.1039/C3NJ01134H
Ultralong H2V3O8 nanowire bundles with length up to hundreds of micrometers were successfully synthesized by a facile hydrothermal approach. The nanowire bundles exhibit a high specific discharge capacity of 325.7 mA h g−1 at 50 mA g−1. While the current density is up to 2000 mA g−1, the initial specific discharge capacities of a H2V3O8 nanowires cathode can reach 121.1 mA h g−1 with a capacity fading of only 0.0425% per cycle for 300 cycles. Electrical transport of a single nanowire is also recorded in situ to detect the evolution of the nanowire during annealing. The conductivity of H2V3O8 nanowire has an increase of three orders of magnitude compared to that of the dehydrated nanowire. The excellent electrochemical performance of H2V3O8 nanowire bundles results from high conductivity and good structural stability. This work demonstrates that H2V3O8 nanowire bundles are a promising cathode material for lithium batteries.
Co-reporter:Lei Zhang, Kangning Zhao, Wangwang Xu, Jiashen Meng, Liang He, Qinyou An, Xu Xu, Yanzhu Luo, Tingwei Zhao and Liqiang Mai
RSC Advances 2014 vol. 4(Issue 63) pp:33332-33337
Publication Date(Web):17 Jul 2014
DOI:10.1039/C4RA06304J
To combine the merits of the one-dimensional structure and the porous structure, mesoporous VO2 nanowires have been designed and reported for the first time. Excellent cycling stability and enhanced rate performance are obtained and may be attributed to the mesoporous nanowires, realizing both high surface area for more active sites and facile stress relaxation resulting in excellent structure stability. Our results demonstrate that the mesoporous nanowires are favourable for high-rate and long-life lithium batteries.
Co-reporter:Wangwang Xu, Kangning Zhao, Chaojiang Niu, Lei Zhang, Zhengyang Cai, Chunhua Han, Liang He, Teng Shen, Mengyu Yan, Longbing Qu, Liqiang Mai
Nano Energy 2014 Volume 8() pp:196-204
Publication Date(Web):September 2014
DOI:10.1016/j.nanoen.2014.06.006
•Heterogeneous branched core–shell SnO2–PANI nanorod arrays have been developed.•The PANI shell releases the stress of volume expansion during cycling.•The SnO2 nanorod arrays maintain mechanical integrity due to the PANI shell.•The PANI shell and the nickel foam realize three dimensional electron transports.•Cycling stability and rate capability are greatly enhanced.SnO2 with high theoretical capacity has long suffered from its instinct large volume variation and low electrical transport linked to poor cycling stability and rate performance. Here we present the heterogeneous branched core–shell SnO2–PANI nanorod arrays which have been successfully designed and fabricated by an efficient and facile hydrothermal treatment followed by electrodeposition. The heterogeneous core–shell SnO2–PANI nanorod arrays exhibit a high reversible capacity of 506 mAh/g after 100 cycles, resulting the capacity fading of 0.579% per cycle between 20 and 100 cycles, much lower than that of nanosheet-assembled hierarchal SnO2–PANI nanorod arrays (1.150%) and bare SnO2 nanorod arrays (1.151%). At high current density of 3000 mA/g, heterogeneous core–shell SnO2–PANI nanorod arrays maintain a capacity of 660 mAh/g after the current density returns to 100 mA/g, 3 times as high as that of nanosheet-assembled hierarchal SnO2–PANI nanorod arrays (206 mAh/g) and 6 times as high as that of bare SnO2 nanorod (124 mAh/g). The enhanced electrochemical performance can be attributed to the branched conductive PANI shells, which not only release the stress of volume expansion and maintain mechanical integrity during cycling, but also realize three dimensional transport for electrons. Our work demonstrates a great potential for the application of heterogeneous branched core–shell PANI–SnO2 nanorod arrays for lithium batteries.
Co-reporter:Jinzhi Sheng;Qidong Li;Qiulong Wei;Pengfei Zhang;Qinqin Wang;Fan Lv
Nano Research 2014 Volume 7( Issue 11) pp:1604-1612
Publication Date(Web):2014 November
DOI:10.1007/s12274-014-0520-1
Co-reporter:Liqiang Mai;Qiulong Wei;Qinyou An;Xiaocong Tian;Yunlong Zhao;Xu Xu;Lin Xu;Liang Chang ;Qingjie Zhang
Advanced Materials 2013 Volume 25( Issue 21) pp:2969-2973
Publication Date(Web):
DOI:10.1002/adma.201205185
Co-reporter:Liqiang Mai;Qiulong Wei;Qinyou An;Xiaocong Tian;Yunlong Zhao;Xu Xu;Lin Xu;Liang Chang ;Qingjie Zhang
Advanced Materials 2013 Volume 25( Issue 21) pp:
Publication Date(Web):
DOI:10.1002/adma.201370140
Co-reporter:Liqiang Mai, Fei Dong, Xu Xu, Yanzhu Luo, Qinyou An, Yunlong Zhao, Jie Pan, and Jingnan Yang
Nano Letters 2013 Volume 13(Issue 2) pp:740-745
Publication Date(Web):January 11, 2013
DOI:10.1021/nl304434v
Inspired by the cucumber-like structure, by combining the in situ chemical oxidative polymerization with facile soaking process, we designed the heterostructured nanomaterial with PEDOT as the shell and MnO2 nanoparticles as the protuberance and synthesized the novel cucumber-like MnO2 nanoparticles enriched vanadium pentoxide/poly(3,4-ethylenedioxythiophene) (PEDOT) coaxial nanowires. This heterostructured nanomaterial exhibits enhanced electrochemical cycling performance with the decreases of capacity fading during 200 cycles from 0.557 to 0.173% over V2O5 nanowires at the current density of 100 mA/g. This method is proven to be an effective technique for improving the electrochemical cycling performance and stability of nanowire electrodes especially at low rate for application in rechargeable lithium batteries.
Co-reporter:Kalele Mulonda Hercule, Qiulong Wei, Aamir Minhas Khan, Yunlong Zhao, Xiaocong Tian, and Liqiang Mai
Nano Letters 2013 Volume 13(Issue 11) pp:5685-5691
Publication Date(Web):October 22, 2013
DOI:10.1021/nl403372n
Pseudocapacitors have demonstrated an ability to deliver high energy and power densities. The main limitation is their poor cyclability and for this reason the architectural design of electrode materials has attracted considerable attention. Here we report the synthesis of hierarchical nanostructured material by growing Co(OH)2 nanoflakes onto MoO2 thin film. The electrode material exhibits a high capacitance of 800 F g–1 at 20 A g–1 with only 3% capacitance loss after 5000 cycles and high rate capability with increasing current density from 2 to 40 A g–1, which are better than those of individual component. The enhanced pseudocapacitor performances benefit from the synergistic effect of the hierarchical nanostructure: (1) faster ion diffusion and electron transport at electrode/electrolyte interface, and (2) mitigation of the electrode destruction caused by ion insertion/deinsertion during charge-storage process. This facile design and rational synthesis offers an effective strategy to enhance the electrochemical performance of pseudocapacitors and shows promising potential for large-scale application in energy storage.
Co-reporter:Mengyu Yan ; Fengchao Wang ; Chunhua Han ; Xinyu Ma ; Xu Xu ; Qinyou An ; Lin Xu ; Chaojiang Niu ; Yunlong Zhao ; Xiaocong Tian ; Ping Hu ; Hengan Wu
Journal of the American Chemical Society 2013 Volume 135(Issue 48) pp:18176-18182
Publication Date(Web):November 12, 2013
DOI:10.1021/ja409027s
Graphene scrolls have been widely investigated for applications in electronics, sensors, energy storage, etc. However, graphene scrolls with tens of micrometers in length and with other materials in their cavities have not been obtained. Here nanowire templated semihollow bicontinuous graphene scroll architecture is designed and constructed through “oriented assembly” and “self-scroll” strategy. These obtained nanowire templated graphene scrolls can achieve over 30 μm in length with interior cavities between the nanowire and scroll. It is demonstrated through experiments and molecular dynamic simulations that the semihollow bicontinuous structure construction processes depend on the systemic energy, the curvature of nanowires, and the reaction time. Lithium batteries based on V3O7 nanowire templated graphene scrolls (VGSs) exhibit an optimal performance with specific capacity of 321 mAh/g at 100 mA/g and 87.3% capacity retention after 400 cycles at 2000 mA/g. The VGS also shows a high conductivity of 1056 S/m and high capacity of 162 mAh/g at a large density of 3000 mA/g with only 5 wt % graphene added which are 27 and 4.5 times as high as those of V3O7 nanowires, respectively. A supercapacitor made of MnO2 nanowire templated graphene scrolls (MGSs) also shows a high capacity of 317 F/g at 1A/g, which is over 1.5 times than that of MnO2 nanowires without graphene scrolls. These excellent energy storage capacities and cycling performance are attributed to the unique structure of the nanowire templated graphene scroll, which provides continuous electron and ion transfer channels and space for free volume expansion of nanowires during cycling. This strategy and understanding can be used to synthesize other nanowire templated graphene scroll architectures, which can be extended to other fabrication processes and fields.
Co-reporter:Liqiang Mai, Shuo Li, Yifan Dong, Yunlong Zhao, Yanzhu Luo and Hongmei Xu
Nanoscale 2013 vol. 5(Issue 11) pp:4864-4869
Publication Date(Web):25 Apr 2013
DOI:10.1039/C3NR01490H
Lithium-ion batteries (LIBs) are receiving considerable attention as storage devices in the renewable and sustainable energy developments. However, facile fabrication of long-life and high-rate cathode materials for LIBs is required to facilitate practical application. Here we report a favourable way to synthesize a Li3V2(PO4)3/C nanosphere cathode with three-dimensional (3D) continuous electron pathways by synergistically utilizing polyethyleneglycol (PEG) and acetylene black for carbon coating and conductive network construction. The as-prepared cathode material has a discharge capacity of 142 mA h g−1 at 1 C rate, approaching its theoretical value (150 mA h g−1), and can even be cycled at a rate as high as 30 C without capacity fading. After 1000 cycles at a rate of 5 C, the as-prepared material has a capacity retention of up to 83%, and can also tolerate 5000 cycles with a considerable capacity, demonstrating excellent cycling stability. Our work shows that this material has great potential for high-energy and high-power energy storage applications, and this rational method can be applied to synthesize high-performance cathode materials on a large scale.
Co-reporter:Yifan Dong, Shuo Li, Hongmei Xu, Mengyu Yan, Xiaoming Xu, Xiaocong Tian, Qing Liu and Liqiang Mai
Physical Chemistry Chemical Physics 2013 vol. 15(Issue 40) pp:17165-17170
Publication Date(Web):14 Aug 2013
DOI:10.1039/C3CP53267D
MoO3 has long suffered from poor conductivity and cyclability, which limit its high rate performance and ultralong cycling ability. Increasing the electronic conductivity with electron pathways of cathode materials can effectively enhance the lithium storage properties with stable cyclability and rate capability theoretically. Here the MoO3–reduced graphene oxide (rGO) hybrid nanobelts were designed and prepared and were tested as cathode materials for lithium batteries. It is demonstrated that the rGO is wrinkled and twisted around MoO3 nanobelts after reacting under high temperature and pressure conditions. The unique morphology of rGO, which has continuous electron pathways and stress buffering effects, endows the MoO3–rGO hybrid nanobelts with significantly increased rate capability and cycling ability. Meanwhile, it is demonstrated that MoO3–rGO hybrid nanobelts are promising cathode materials for use in rechargeable lithium batteries and our synthesis strategy is also versatile for exploiting advanced materials for Li-ion batteries.
Co-reporter:Qinyou An, Qiulong Wei, Liqiang Mai, Jiayang Fei, Xu Xu, Yunlong Zhao, Mengyu Yan, Pengfei Zhang and Shizhe Huang
Physical Chemistry Chemical Physics 2013 vol. 15(Issue 39) pp:16828-16833
Publication Date(Web):31 Jul 2013
DOI:10.1039/C3CP52624K
Ultrathin V2O5 nanosheets were successfully prepared through supercritical solvothermal reaction followed by annealing treatment. The formation of ultrathin nanosheets is owing to Ostwald ripening and the effect of supercritical fluids. As cathode material for lithium batteries, the ultrathin V2O5 nanosheets exhibit a capacity of 108 mA h g−1 at a high rate of up to 10 C at 2.4–4 V and excellent cyclability with little capacity loss after 200 cycles. The enhanced rate performance is attributed to the shortened diffusion distance and the increased electrode–electrolyte contact area of the ultrathin nanosheet structure. It is also demonstrated that the supercritical solvothermal method is effective and facile to scalably synthesize ultrathin nanomaterials for lithium batteries.
Co-reporter:Liang Chang, Liqiang Mai, Xu Xu, Qinyou An, Yunlong Zhao, Dandan Wang and Xi Feng
RSC Advances 2013 vol. 3(Issue 6) pp:1947-1952
Publication Date(Web):27 Nov 2012
DOI:10.1039/C2RA22735E
Mesoporous structures have attracted increasing interest in improving the cycling life and specific capacity of electrode materials. Mn2O3 microspheres with controlled pore size were successfully synthesized by morphology-conserved transformation at 500, 700 and 900 °C. Among them, mesoporous Mn2O3 microspheres annealed at 500 °C show the highest discharge capacity, the minor capacity fading per cycle and ultralong cycling life. It can realize 1000 stable charge/discharge processes with 125 mAh g−1 reversible capacity at current density of 1000 mA g−1. Meanwhile, at relatively low current density (200 mA g−1), it can deliver capacity of 524 mAh g−1 after 200 cycles. The remarkable electrochemical performance can result from the relatively high surface area and abundant surface active sites of mesoporous structure, which can enhance the continuous charge transfer kinetics, ion diffusion and capacity. The high cycling stability and long life span make mesoporous Mn2O3 microspheres promising electrode materials for electrochemical energy storage.
Co-reporter:Chunhua Han, Mengyu Yan, Liqiang Mai, Xiaocong Tian, Lin Xu, Xu Xu, Qinyou An, Yunlong Zhao, Xinyu Ma, Junlin Xie
Nano Energy 2013 Volume 2(Issue 5) pp:916-922
Publication Date(Web):September 2013
DOI:10.1016/j.nanoen.2013.03.012
•V2O5 Quantum dots/graphene hybrid nanocomposite was constructed and the V2O5 quantum dots held an average size of 2–3 nm.•The specific capacity can achieve 212 mA h g−1 at 100 mA g−1 after 100 cycles which is twice than that of V2O5 nanowires.•V2O5 quantum dots/graphene shows a stable cycling performance with 89% capacity retention after 300 cycles.•The improvement in electrochemical properties attribute to the short Li ion transfer distance, two-dimensional electron channels, homogeneous dispersion and immobilization of V2O5 quantum dots.High-speed electron transfer channels and short Li ion transport distance are beneficial to improvement of Li ion battery properties. Here, a two-step solution phase synthesis method is developed to construct the V2O5 quantum dots/graphene hybrid nanocomposite by controlling nucleation and growth processes. It is demonstrated that the V2O5 quantum dots with an average size of 2-3 nm are uniformly anchored on the graphene sheets. The specific capacity can achieve 212 mA h g−1 at 100 mA g−1 after 100 cycles. Significantly, the novel V2O5 quantum dots/graphene shows a stable cycling performance with 89% capacity retention after 300 cycles. The improvement in electrochemical properties could be attributed to the short Li ion transfer distance, two-dimensional electron channels, homogeneous dispersion and immobilization of V2O5 quantum dots. Meanwhile, it indicates that V2O5 quantum dots/graphene is promising cathode material for use in long-life rechargeable lithium batteries. This design conception and synthesis strategy for V2O5 could also be extended to other electrode material systems.Graphical abstract
Co-reporter:Chunhua Han, Yuqiang Pi, Qinyou An, Liqiang Mai, Junlin Xie, Xu Xu, Lin Xu, Yunlong Zhao, Chaojiang Niu, Aamir Minhas Khan, and Xiaoyun He
Nano Letters 2012 Volume 12(Issue 9) pp:4668-4673
Publication Date(Web):August 3, 2012
DOI:10.1021/nl301993v
Rational assembly of unique complex nanostructures is one of the facile techniques to improve the electrochemical performance of electrode materials. Here, a substrate-assisted hydrothermal method was designed and applied in synthesizing moundlily like radial β-AgVO3 nanowire clusters. Gravitation and F– ions have been demonstrated to play important roles in the growth of β-AgVO3 nanowires (NWs) on substrates. The results of cyclic voltammetry (CV) measurement and X-ray diffraction (XRD) characterization proved the phase transformation from β-AgVO3 to Ag1.92V4O11 during the redox reaction. Further electrochemical investigation showed that the moundlily like β-AgVO3 nanowire cathode has a high discharge capacity and excellent cycling performance, mainly due to the reduced self-aggregation. The capacity fading per cycle from 3rd to 51st is 0.17% under the current density of 500 mA/g, which is much better than 1.46% under that of 20 mA/g. This phenomenon may be related to the Li+ diffusion and related kinetics of the electrode. This method is shown to be an effective and facile technique for improving the electrochemical performance for applications in rechargeable Li batteries or Li ion batteries.
Co-reporter:Xu Xu, Yan-Zhu Luo, Li-Qiang Mai, Yun-Long Zhao, Qin-You An, Lin Xu, Fan Hu, Lei Zhang and Qing-Jie Zhang
NPG Asia Materials 2012 4(6) pp:e20
Publication Date(Web):2012-06-01
DOI:10.1038/am.2012.36
High-power applications at fast charge and discharge rates are still significant challenges in the development of rechargeable lithium (Li) batteries. Here, we demonstrate that ultralong LiV3O8 nanowire cathode materials synthesized by topotactic Li intercalation are capable of excellent high-rate performance with minimal capacity loss. A specific discharge capacity of 176 mAh g−1 can be obtained at the current density of 1500 mA g−1, and the capacity is able to stabilize at 160 mAh g−1 after 400 cycles, corresponding to 0.025% capacity fading per cycle. For current density up to 2000, mA g−1, the initial and the six-hundredth cycle capacities can reach 137 and 120 mAh g−1, respectively, corresponding to a capacity fading of only 0.022% per cycle. The ability to provide this level of performance is attributed to a low-charge-transfer resistance, good structural stability, large surface area and suitable degree of crystallinity, and it indicates that LiV3O8 nanowires are promising cathode materials for use in high-rate and long-life rechargeable Li batteries.
Co-reporter:Fangyu Xiong, Shuangshuang Tan, Qiulong Wei, Guobin Zhang, Jinzhi Sheng, Qinyou An, Liqiang Mai
Nano Energy (February 2017) Volume 32() pp:
Publication Date(Web):February 2017
DOI:10.1016/j.nanoen.2016.12.050
•The reversible sodium-ion storage of Li3V2(PO4)3 is investigated for the first time.•The modified Li3V2(PO4)3 achieved a high energy density of 501.3 Wh kg−1.•The sodium-ion storage mechanism of Li3V2(PO4)3 is topotactic reaction.Li3V2(PO4)3 (LVP) was evaluated as a promising cathode material for sodium-ion batteries (SIBs). The three-dimensional graphene frameworks wrapped LVP (LVP-G-FD) exhibited high energy density of 501.3 Wh kg−1, which is almost the highest energy density among the known polyanionic cathodes for SIBs. The enhanced electrochemical performance of LVP-G-FD is attributed to the graphene framework which provides the fast electronic transport network and buffering space. Besides, the sodium-ion storage mechanism of LVP was investigated via in-situ XRD and so on. The sodium-ion storage process is composed of the electrochemical topotactic replacement and the subsequent topotactic reaction.
Co-reporter:Chunjuan Tang, Jiexin Zhu, Xiujuan Wei, Liang He, Kangning Zhao, Chang Xu, Liang Zhou, Bo Wang, Jinzhi Sheng, Liqiang Mai
Energy Storage Materials (April 2017) Volume 7() pp:152-156
Publication Date(Web):1 April 2017
DOI:10.1016/j.ensm.2017.01.008
Copper silicate (CSO) is a promising anode material for lithium-ion batteries (LIBs). It delivers high specific capacity; however, the capacity fades quickly because of its intrinsic poor electric conductivity and large volume variation during lithium ion insertion/extraction. Herein, a sandwich-like structure with CSO nanotubes grown on both sides of reduced graphene oxide (RGO) is designed to solve the capacity fading issue. The RGO not only serves as a soft and robust matrix to mitigate the large volume change during cycling but also acts as the electron highway. When applied as the anode material for LIBs, the as-obtained CSO/RGO sandwich-like structure exhibits high reversible capacity, good rate capability, and excellent cycling stability. A reversible capacity of 516 mA h g−1 can be achieved after 1000 cycles at 500 mA g−1.
Co-reporter:Chaojiang Niu ; Jiashen Meng ; Chunhua Han ; Kangning Zhao ; Mengyu Yan
Nano Letter () pp:
Publication Date(Web):April 17, 2014
DOI:10.1021/nl500915b
Development of three-dimensional nanostructures with high surface area and excellent structural stability is an important approach for realizing high-rate and long-life battery electrodes. Here, we report VO2 hollow microspheres showing empty spherical core with radially protruding nanowires, synthesized through a facile and controllable ion-modulating approach. In addition, by controlling the self-assembly of negatively charged C12H25SO4– spherical micelles and positively charged VO2+ ions, six-armed microspindles and random nanowires are also prepared. Compared with them, VO2 hollow microspheres show better electrochemical performance. At high current density of 2 A/g, VO2 hollow microspheres exhibit 3 times higher capacity than that of random nanowires, and 80% of the original capacity is retained after 1000 cycles. The superior performance of VO2 hollow microspheres is because they exhibit high surface area about twice higher than that of random nanowires and also provide an efficient self-expansion and self-shrinkage buffering during lithiation/delithiation, which effectively inhibits the self-aggregation of nanowires. This research indicates that VO2 hollow microspheres have great potential for high-rate and long-life lithium batteries.
Co-reporter:Jiashen Meng, Ziang Liu, Chaojiang Niu, Xiaoming Xu, Xiong Liu, Guobin Zhang, Xuanpeng Wang, Meng Huang, Yang Yu and Liqiang Mai
Journal of Materials Chemistry A 2016 - vol. 4(Issue 13) pp:NaN4899-4899
Publication Date(Web):2016/03/02
DOI:10.1039/C6TA00556J
Layered metal vanadates, especially alkali metal vanadates, have been extensively studied in energy storage. Generally, vanadates exhibit more stable electrochemical performance than pristine vanadium oxides, and different vanadates also vary in the performance. However, the detailed mechanisms of the variation in the performance of vanadates and vanadium oxides are poorly explored. Here we choose and construct three typical layered vanadium-based nanowires (V2O5, KV3O8 and K0.25V2O5), and investigate the origin of the enhanced electrochemical performance of the potassium vanadates compared to V2O5, based on crystal structure analysis, electrochemical tests, ex situ ICP measurements and in situ XRD detections. We demonstrate a synergistic effect between layer surface configurations and K ions of potassium vanadate nanowires, which leads to the great improvement in electrochemical stability of K0.25V2O5. The layer surface configuration of K0.25V2O5 only consists of single-connected oxygen atoms, which provides strong interaction with the K ions. And the stabilized K ions act as “pillars” between interlayers to protect the layered structures from collapse in the charge/discharge process. This work provides a further insight into alkali metal vanadates, and benefits the design of ideal electrode materials in the energy storage field.
Co-reporter:Yifan Dong, Shuo Li, Hongmei Xu, Mengyu Yan, Xiaoming Xu, Xiaocong Tian, Qing Liu and Liqiang Mai
Physical Chemistry Chemical Physics 2013 - vol. 15(Issue 40) pp:NaN17170-17170
Publication Date(Web):2013/08/14
DOI:10.1039/C3CP53267D
MoO3 has long suffered from poor conductivity and cyclability, which limit its high rate performance and ultralong cycling ability. Increasing the electronic conductivity with electron pathways of cathode materials can effectively enhance the lithium storage properties with stable cyclability and rate capability theoretically. Here the MoO3–reduced graphene oxide (rGO) hybrid nanobelts were designed and prepared and were tested as cathode materials for lithium batteries. It is demonstrated that the rGO is wrinkled and twisted around MoO3 nanobelts after reacting under high temperature and pressure conditions. The unique morphology of rGO, which has continuous electron pathways and stress buffering effects, endows the MoO3–rGO hybrid nanobelts with significantly increased rate capability and cycling ability. Meanwhile, it is demonstrated that MoO3–rGO hybrid nanobelts are promising cathode materials for use in rechargeable lithium batteries and our synthesis strategy is also versatile for exploiting advanced materials for Li-ion batteries.
Co-reporter:Wenhao Ren, Zhiping Zheng, Yanzhu Luo, Wei Chen, Chaojiang Niu, Kangning Zhao, Mengyu Yan, Lei Zhang, Jiashen Meng and Liqiang Mai
Journal of Materials Chemistry A 2015 - vol. 3(Issue 39) pp:NaN19856-19856
Publication Date(Web):2015/08/17
DOI:10.1039/C5TA04643B
Structural and morphological control of the LiV3O8 material has a significant impact on its electrochemical performance. In order to obtain a favorable structure, a hierarchical LiV3O8 nanowire-in-network is designed and constructed by electrospinning through a polymer crosslinking strategy. The crosslinking effect between poly(vinyl alcohol) (PVA) and poly(ethylene oxide) (PEO) not only benefits electrospinning, but also realizes a mild multi-step degradation process during calcination. Based on temperature-dependent experiments and thermogravimetric (TG) analysis, the function of polymer blends and the formation mechanism of the structure are discussed in detail. As a cathode for lithium batteries, LiV3O8 exhibits a high initial capacity of 320.6 mA h g−1 at 100 mA g−1 and a high-rate capacity of 202.8 mA h g−1 at 2000 mA g−1. This remarkable performance is attributed to its unique structure, which provides a large effective contact area, low charge transfer resistance, and improved structural stability. Our work indicates that the hierarchical LiV3O8 nanowire-in-network material is a promising cathode for use in high-rate and long-life rechargeable lithium batteries.
Co-reporter:Qinyou An, Qiulong Wei, Liqiang Mai, Jiayang Fei, Xu Xu, Yunlong Zhao, Mengyu Yan, Pengfei Zhang and Shizhe Huang
Physical Chemistry Chemical Physics 2013 - vol. 15(Issue 39) pp:NaN16833-16833
Publication Date(Web):2013/07/31
DOI:10.1039/C3CP52624K
Ultrathin V2O5 nanosheets were successfully prepared through supercritical solvothermal reaction followed by annealing treatment. The formation of ultrathin nanosheets is owing to Ostwald ripening and the effect of supercritical fluids. As cathode material for lithium batteries, the ultrathin V2O5 nanosheets exhibit a capacity of 108 mA h g−1 at a high rate of up to 10 C at 2.4–4 V and excellent cyclability with little capacity loss after 200 cycles. The enhanced rate performance is attributed to the shortened diffusion distance and the increased electrode–electrolyte contact area of the ultrathin nanosheet structure. It is also demonstrated that the supercritical solvothermal method is effective and facile to scalably synthesize ultrathin nanomaterials for lithium batteries.
Co-reporter:Chunjuan Tang, Jinzhi Sheng, Chang Xu, S. M. B. Khajehbashi, Xuanpeng Wang, Ping Hu, Xiujuan Wei, Qiulong Wei, Liang Zhou and Liqiang Mai
Journal of Materials Chemistry A 2015 - vol. 3(Issue 38) pp:NaN19432-19432
Publication Date(Web):2015/08/10
DOI:10.1039/C5TA04680G
Layered silicate is a new type of electrode material with high reversible capacity. However, its poor electrical conductivity leads to rapid capacity decay. To solve this problem, reduced graphene oxide (RGO) wrapped nickel silicate (NiSiO) hollow spheres are successfully synthesized. The hollow structure provides sufficient free space to accommodate the volume variation during lithiation/de-lithiation and the RGO improves the electrical conductivity. The resulting NiSiO/RGO delivers a capacity of 400 mA h g−1 at 500 mA g−1 after 1000 cycles, making the NiSiO/RGO composite a promising anode material for lithium-ion batteries.
Co-reporter:Lei Zhang, Kangning Zhao, Wangwang Xu, Yifan Dong, Rui Xia, Fengning Liu, Liang He, Qiulong Wei, Mengyu Yan and Liqiang Mai
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 12) pp:NaN7623-7623
Publication Date(Web):2015/02/10
DOI:10.1039/C5CP00150A
Conversion/alloying reactions, in which more lithium ions are involved, are severely handicapped by the dramatic volume changes. A facile and versatile strategy has been developed for integrating the SnO2 nanorod array in the PPy nanofilm for providing a flexible confinement for anchoring each nanorod and maintaining the entire structural integrity and providing sustainable contact; therefore, exhibiting much more stable cycling stability (701 mA h g−1 after 300 cycles) and better high-rate capability (512 mA h g−1 at 3 A g−1) when compared with the core–shell SnO2–PPy NA.
Co-reporter:Qiulong Wei, Jin Liu, Wei Feng, Jinzhi Sheng, Xiaocong Tian, Liang He, Qinyou An and Liqiang Mai
Journal of Materials Chemistry A 2015 - vol. 3(Issue 15) pp:NaN8075-8075
Publication Date(Web):2015/03/02
DOI:10.1039/C5TA00502G
Sodium ion batteries (SIBs), as potential candidates for large-scale energy storage systems, have attracted great attention from researchers. Herein, a V2O5·nH2O xerogel composed of thin acicular interconnected nanowire networks has been synthesized via a facile freeze-drying process. The interlayer spacing of V2O5·nH2O is larger than that of orthorhombic V2O5 due to the intercalation of water molecules into the layer structure. As the cathode of a SIB, V2O5·nH2O exhibits a high initial capacity of 338 mA h g−1 at 0.05 A g−1 and a high-rate capacity of 96 mA h g−1 at 1.0 A g−1. On the basis of combining ex-situ XRD and FTIR spectroscopy, the Na+ ion intercalation storage reactions are discussed in detail. By modeling calculations, the pseudocapacitive behavior makes a great contribution to the high capacities. Our work demonstrates that V2O5·nH2O with large interlayer spacing is a promising candidate for high capacity sodium-based energy storage.
Co-reporter:Yanzhu Luo, Xu Xu, Xiaocong Tian, Qiulong Wei, Mengyu Yan, Kangning Zhao, Xiaoming Xu and Liqiang Mai
Journal of Materials Chemistry A 2016 - vol. 4(Issue 14) pp:NaN5080-5080
Publication Date(Web):2016/03/02
DOI:10.1039/C6TA01339B
Hollow microspheres with a high surface area, sufficient void space, and short ion/electron transport distance have attracted much attention as a superior electrode structure for high-rate lithium-ion batteries. In this work, a facile and low-cost hydrothermal approach followed by annealing is developed to synthesize Co3V2O8 interconnected hollow microspheres, which are able to endure an extremely high current density of 20 A g−1 and achieve a reversible discharge capacity of 320 mA h g−1. Furthermore, a stable capacity of 424 mA h g−1 can be obtained after 300 cycles at 10 A g−1. Such remarkable rate capability and cycling performance make the Co3V2O8 interconnected hollow microspheres a promising anode material for lithium-ion batteries.
Co-reporter:Chao Lin, Chaojiang Niu, Xu Xu, Ke Li, Zhengyang Cai, Yonglai Zhang, Xuanpeng Wang, Longbing Qu, Yuxi Xu and Liqiang Mai
Physical Chemistry Chemical Physics 2016 - vol. 18(Issue 32) pp:NaN22153-22153
Publication Date(Web):2016/07/05
DOI:10.1039/C6CP03624D
Compared with a two dimensional graphene sheet, a three dimensional (3D) graphene sponge has a continuous conductive structure and numerous pores, which are beneficial for sulfur utilization and anchoring. However, strategies for the construction of 3D graphene sponges composited with sulfur nanoparticles (3DGS) are either energy consuming or involve toxic reagents. Herein, a 3DGS is fabricated via a reduction induced self-assembly method, which is simple but facile and scalable. The structural design of this 3DGS promises fast Li+ transport, superior electrolyte absorbability and effective electrochemical redox reactions of sulfur. As a result, this 3DGS achieves a stable capacity of 580 mA h g−1 after 500 cycles at a high rate of 1.5 A g−1, which corresponds to a low fading rate of 0.043% per cycle. The present study effectively demonstrates that the 3D construction strategy is propitious for obtaining flexible high performance Li–S batteries.
Co-reporter:Zhaohuai Li, Qiu He, Liang He, Ping Hu, Wei Li, Haowu Yan, Xianzhou Peng, Congyun Huang and Liqiang Mai
Journal of Materials Chemistry A 2017 - vol. 5(Issue 8) pp:NaN4189-4189
Publication Date(Web):2017/01/23
DOI:10.1039/C6TA10583A
Silicon oxide (SiOx) shows great potential for lithium ion battery (LIB) anodes due to its high capacity, environmental friendliness, low cost and high abundance. Herein, we used low-cost mesoporous silica spheres to synthesize core–shell structured porous carbon-coated SiOx nanowires (pC–SiOx NWs) as a new LIB anode through a novel self-sacrificed method. The one-dimensional structure can accommodate large volume expansion without breaking. The porous carbon coating hinders the penetration of the electrolyte into pC–SiOx NWs and formation of a stable solid-electrolyte interphase (SEI) film on the external surface of pC–SiOx NWs. As a result, the composite shows excellent cycling stability with high reversible specific capacities of 1060 mA h g−1 (100 cycles) and 623 mA h g−1 (150 cycles) at current densities of 100 mA g−1 and 500 mA g−1, respectively. The proposed facile and scalable synthesis is highly competitive for large-scale applications in lithium storage devices/systems.
Co-reporter:Qidong Li, Qiulong Wei, Qinqin Wang, Wen Luo, Qinyou An, Yanan Xu, Chaojiang Niu, Chunjuan Tang and Liqiang Mai
Journal of Materials Chemistry A 2015 - vol. 3(Issue 37) pp:NaN18842-18842
Publication Date(Web):2015/08/18
DOI:10.1039/C5TA05594F
A hollow shell-controlled Li3VO4 is fabricated via a facile self-template method, which has a controllable shell thickness in the range of 10–300 nm. This hollow shell-controlled Li3VO4 composited with reduced graphene oxide exhibits excellent rate capability (201 mA h g−1 at 125 C) and superior high-temperature stability (364.2 mA h g−1 after 1000 cycles at 10 C, 60 °C).
Co-reporter:Qinyou An, Pengfei Zhang, Qiulong Wei, Liang He, Fangyu Xiong, Jinzhi Sheng, Qinqin Wang and Liqiang Mai
Journal of Materials Chemistry A 2014 - vol. 2(Issue 10) pp:NaN3302-3302
Publication Date(Web):2013/12/12
DOI:10.1039/C3TA14818A
Three-dimensional porous V2O5 hierarchical microplates have been fabricated by a one-step top-down strategy, and display an excellent rate capability and stable capacity of 110 mA h g−1 at 2000 mA g−1 after 100 cycles. We have demonstrated that the facile approach of a solid-phase conversion is promising for large-scale fabrication of highly porous micro/nano materials.
Co-reporter:Qiulong Wei, Yanan Xu, Qidong Li, Shuangshuang Tan, Wenhao Ren, Qinyou An and Liqiang Mai
Chemical Communications 2016 - vol. 52(Issue 56) pp:NaN8732-8732
Publication Date(Web):2016/06/08
DOI:10.1039/C6CC03629E
Novel layered Li3V2(PO4)3/rGO&C sheets are synthesized by novel interfacial modified assembly, freeze-drying and confined annealing processes. The uniform LVP layers are alternated with rGO&C layers to form the composite layered structure, providing effective electron and ion transport. As a lithium-ion battery cathode, the composite displays excellent electrochemical performance.
Co-reporter:Jun Dong, Yalong Jiang, Qidong Li, Qiulong Wei, Wei Yang, Shuangshuang Tan, Xu Xu, Qinyou An and Liqiang Mai
Journal of Materials Chemistry A 2017 - vol. 5(Issue 22) pp:NaN10835-10835
Publication Date(Web):2017/05/03
DOI:10.1039/C7TA00463J
Titanium oxynitride mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized, based on an anion exchange process. By investigating the electrochemical performance, it is found to exhibit high pseudocapacitive sodium storage performance, demonstrated by kinetic analysis and experimental characterizations. Subsequently, the assembled asymmetric hybrid sodium ion capacitor (AC//Ti(O,N)) exhibits high energy and power densities. Our work proposes the high pseudocapacitance in non-aqueous sodium ion system is very promising for high-power and low-cost energy storage applications.
Co-reporter:Di Wang, Qiulong Wei, Jinzhi Sheng, Ping Hu, Mengyu Yan, Ruimin Sun, Xiaoming Xu, Qinyou An and Liqiang Mai
Physical Chemistry Chemical Physics 2016 - vol. 18(Issue 17) pp:NaN12079-12079
Publication Date(Web):2016/03/29
DOI:10.1039/C6CP00745G
Sodium ion batteries (SIBs) have emerged as a potential candidate to succeed lithium ion batteries (LIBs), because of the abundant sodium resources on earth. Layered vanadium oxides are regarded as the promising candidates for SIBs because of their large interlayer spacing, high theoretical specific capacity, abundant sources and low cost. In this paper, a vanadium oxide hydrate (H2V3O8) nanowire membrane is presented as a flexible cathode for SIBs without addition of any other additives (binders or conductive compounds). Such a freestanding flexible membrane exhibits a high specific capacity of 168 mA h g−1 at 10 mA g−1, and its high capacity is maintained well after 100 cycles. It is found that the capacitive charge storage accounts for a relatively large proportion of the total capacity, whereas the crystal structure of H2V3O8 is highly reversible during the sodiation/desodiation processes. This research demonstrates that the H2V3O8 nanowire is an exceptional candidate for SIBs.
Co-reporter:Xiong Liu, Chaojiang Niu, Jiashen Meng, Xiaoming Xu, Xuanpeng Wang, Bo Wen, Ruiting Guo and Liqiang Mai
Journal of Materials Chemistry A 2016 - vol. 4(Issue 37) pp:NaN14100-14100
Publication Date(Web):2016/08/17
DOI:10.1039/C6TA06016A
We develop a facile gradient-temperature hydrothermal method to synthesize hierarchical Zn2SnO4 hollow boxes based on phase transformation between metastable ZnSnO3 and stable Zn2SnO4. This strategy is widely extended to ZnSnO3 microspheres, ZnSn(OH)6 nanocubes and Co-ZIF-67 polyhedrons. When employed as a LIB anode, Zn2SnO4 hollow boxes exhibit apparently enhanced electrochemical performance.
Co-reporter:Xiujuan Wei, Qinyou An, Qiulong Wei, Mengyu Yan, Xuanpeng Wang, Qidong Li, Pengfei Zhang, Bolun Wang and Liqiang Mai
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 35) pp:NaN18685-18685
Publication Date(Web):2014/07/24
DOI:10.1039/C4CP02762K
Bowknot-like RuO2 quantum dots@V2O5 nanomaterials have been synthesized by a facile hydrothermal method followed by annealing treatment, which exhibit largely enhanced electrochemical performance. Especially, the RuO2 quantum dots@V2O5 cathode delivers 160 mA h g−1 at 1000 mA g−1 after 100 cycles, which is much higher than 86 mA h g−1 of the pure V2O5 cathode.
