Co-reporter:Can Cao;Shichao Zhang;Bin Pan;Gaoshao Cao;Xinbing Zhao
Journal of Materials Chemistry A 2017 vol. 5(Issue 14) pp:6747-6755
Publication Date(Web):2017/04/04
DOI:10.1039/C7TA00416H
Lithium–oxygen (Li–O2) cells are receiving intense interest because of their extremely high energy density. A highly efficient catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key factor influencing the performance of lithium–oxygen cells. In this work, we prepared a highly efficient CeO2-decorated δ-MnO2 (CeO2/δ-MnO2) catalyst which is composed of graphene-like δ-MnO2 with ultrafine CeO2 nanocrystals decorated on it. Li–O2 cells with the CeO2/δ-MnO2 catalyst exhibit superior electrochemical performance, including high discharge specific capacity (8260 mA h g−1 at 100 mA g−1), good rate capability (735 mA h g−1 at 1600 mA g−1), and excellent cycling stability (296 cycles at a limited capacity of 500 mA h g−1), which is much better than that with a bare δ-MnO2 catalyst. The achievement of excellent electrochemical performance is attributed to the highly efficient co-catalytic ability of δ-MnO2 and CeO2 and the desirable graphene-like architecture of the CeO2/δ-MnO2 catalyst, as well as the formation of the thin-layered discharge product Li2O2.
Co-reporter:Xueke Xia, Jian Xie, Shichao Zhang, Bin Pan, ... Xinbing Zhao
Journal of Materials Science & Technology 2017 Volume 33, Issue 8(Volume 33, Issue 8) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.jmst.2016.09.017
Sodium-ion batteries (SIBs) recently have received a worldwide attention due to the resource abundance of sodium and similar battery chemistry with lithium-ion batteries (LIBs). However, search for suitable anodes for SIBs still remains a challenge since graphitized carbon, the anode for commercial LIBs, usually exhibits low electrochemical Na-storage activity. In this work, a unique graphene-reinforced Ni3S2 thin film (Ni3S2/G) has been constructed and investigated as a promising anode for SIBs. The Ni3S2 thin film has a thickness of 200–300 nm and is composed of small sized crystals of around 100 nm. The graphene has a wrinkled surface profile which offers three-dimensional networks for electron conductivity and structural reinforcement. The Ni3S2/G thin film exhibits high capacity, excellent cycling stability and good rate capability due to the introduction of wrinkled graphene. Ni3S2/G can deliver a high initial capacity of 791 mAh g−1 at 50 mA g−1. The capacity can be maintained at 563 mAh g−1 after 110 cycles. This work provides a unique design for high-performance SIBs anodes.Download high-res image (192KB)Download full-size image
Co-reporter:Cong Tang, Pengcheng Sun, Jian Xie, Zhichu Tang, Zixu Yang, Zexi Dong, Gaoshao Cao, Shichao Zhang, Paul V. Braun, Xinbing Zhao
Energy Storage Materials 2017 Volume 9(Volume 9) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.ensm.2017.07.016
Li–O2 cells have attracted a worldwide attention due to their extremely high energy density compared with current Li-ion batteries. However, great challenges must to be overcome to realize full charge and discharge of Li–O2 cells at high rates over a wide electrochemical window. Herein, we propose a unique design of binder-free catalytic cathode composed of two-dimensional (2D), few-layered δ-MnO2 (5–10 nm) decorated with small-sized IrO2 (around 5 nm). The superior catalytic activity of IrO2/MnO2 enables conformal growth of amorphous Li2O2 on the 2D IrO2/MnO2 nanosheets at high current density, leading to significantly enhanced Li2O2 formation/decomposition kinetics. As a result, Li–O2 cells with the IrO2/MnO2 catalyst exhibit high capacity (16370 mAh g−1 at 200 mA g−1), superior rate capability (2315 mAh g−1 at 1600 mA g−1) and high-rate cycling stability (312 cycles at 1600 mA g−1) between 2.2 and 4.3 V. Even over a wider voltage window of 2–4.4 V, the cell can sustain 247 cycles at 1600 mA g−1 in a full charge/discharge mode. The superior catalytic activity of IrO2/MnO2 makes it a promising catalyst for high-performance Li–O2 cells.Download high-res image (345KB)Download full-size image
Co-reporter:Xueke Xia, Qiannan Wang, Qi Zhu, Jian Xie, Jiangwei Wang, Dagao Zhuang, Shichao Zhang, Gaoshao Cao, Xinbing Zhao
Materials Today Energy 2017 Volume 5(Volume 5) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.mtener.2017.05.003
•Array-type Ni3S2/ACS is grown directly on Ni substrate as Na storage anode.•Ni3S2 exhibits a thin-layered structure and is sheathed by amorphous carbon.•The volume expansion of Ni3S2 upon sodiation is confined inside ACS.•Sodiation/desodiation process is real time monitored by in situ TEM technique.The past few years have witnessed increasing attention of sodium ion batteries due to the concerns on the shortage of lithium resources. Great challenge, however, remains to develop anode materials with high capacity and long cycle life. In this work, a binder-free array-type electrode, constructed of nickel sulfide (Ni3S2) nanoparticles encapsulated in amorphous carbon sheath (ACS), was fabricated by a facile templating method. This array-type Ni3S2/ACS electrode can yield a high initial reversible capacity of 772 mAh g−1 and a long cycle life with a reversible capacity of 440 mAh g−1 retained after 100 cycles. Both ex situ and in situ characterizations reveal that the excellent electrochemical performance of Ni3S2/ACS electrode originates from the unique array-type structure, in which high activity of Ni3S2 can be obtained by the thin-layered structure and the sodiation-induced volume expansion of Ni3S2 can be effectively accommodated by the carbon sheath and inner space, resulting in a high mechanical stability of the Ni3S2/ACS rods during cycling. Our results reveal the electrochemical performance and fundamental reaction mechanism of Ni3S2/ACS during sodiation-desodiation cycles, shedding lights onto the design of novel sulfide-based anodes for sodium ion batteries.Download high-res image (228KB)Download full-size image
Co-reporter:Xueke Xia;Shichao Zhang;Bin Pan;Gaoshao Cao;Xinbing Zhao
Inorganic Chemistry Frontiers 2017 vol. 4(Issue 1) pp:131-138
Publication Date(Web):2017/01/13
DOI:10.1039/C6QI00286B
Owing to the increasing concerns regarding limited lithium reserves, sodium-ion batteries (SIBs) have attained worldwide attention in recent years. However, there is still a challenge to find suitable anodes for SIBs with high capacity and a long cycle life. In this work, we propose a unique feather-like array-type anode composed of thin Ni3S2 nanosheets anchored on cracked carbon submicron tubes (CSTs) on a porous Ni foam substrate. The porous structure of the Ni foam facilitates electrode wetting by the electrolyte. The voids in between the Ni3S2/CST arrays provide free space for buffering volume changes upon sodiation/desodiation. The CSTs not only act as the support for Ni3S2 growth but also uniformly disperse the Ni3S2 nanosheets, leading to high capacity and good capacity retention. The Ni-supported Ni3S2/CSTs can deliver a high initial reversible capacity of 887 mA h g−1 at 50 mA g−1. The reversible capacity can be kept at 212 mA h g−1 after 260 cycles. This work will shed light on the design of high-performance SIB anodes.
Co-reporter:Can Cao, Yucong Yan, Hui Zhang, Jian Xie, Shichao Zhang, Bin Pan, Gaoshao Cao, and Xinbing Zhao
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 46) pp:31653
Publication Date(Web):November 1, 2016
DOI:10.1021/acsami.6b10716
For Li–O2 batteries, a challenge still remains to achieve high discharge capacity and easy decomposition of the discharge product (Li2O2) simultaneously. In this work, conformal growth of thin-layered Li2O2 on Co3O4 nanowire arrays (Co3O4 NAs) during discharge is realized through the cocatalytic effect of solid/immobile Co3O4 NAs and mobile Pd nanocrystals (Pd NCs), rendering easy decomposition of Li2O2 during recharge. Meanwhile, high discharge capacity is also ensured with unique array-type design of the catalytic cathode despite the surface growth mode of Li2O2. The Li–O2 cells can deliver a high discharge capacity of 5337 mAh g–1 and keep a stable cycling of 258 cycles at a limited capacity of 500 mAh g–1. The achievement of excellent electrochemical performance is attributed to the highly efficient cocatalytic ability of Co3O4 NAs and Pd NCs as well as the desirable array-type architecture of the catalytic electrode free of carbon and binder. The cocatalytic mechanism of Co3O4 NAs and Pd NCs is clarified by systematic electrochemical tests, microstructural analyses, and ζ-potential measurements.Keywords: binder/carbon free; cobalt oxide arrays; cocatalysis; controlled Li2O2 growth; lithium−oxygen batteries; palladium nanocrystals
Co-reporter:Liliang Huang, Yangjun Mao, Guoqing Wang, Xueke Xia, Jian Xie, Shichao Zhang, Gaohui Du, Gaoshao Cao and Xinbing Zhao
New Journal of Chemistry 2016 vol. 40(Issue 8) pp:6812-6818
Publication Date(Web):01 Jun 2016
DOI:10.1039/C6NJ01364C
The working principle of Li–air (Li–O2) batteries is based on the formation/decomposition of Li2O2 on the catalytic electrode, which is basically different from the shuttle mechanism of Li-ion batteries. The successful operation of Li–O2 batteries requires an optimized cathode that is electrochemically/chemically stable, mechanically robust, and catalytically active. In this work, we proposed a unique design of a binder/carbon-free catalytic cathode consisting of knitted Co3O4 nanowires and decorated Ru nanoparticles. It was found that the Co3O4/Ru-catalyzed Li–O2 batteries exhibit considerably higher capacity and much improved cycling performance than the Co3O4-catalyzed ones. When the capacity is limited at 500 mA h g−1, the Co3O4/Ru-catalyzed battery can sustain a stable cycling of 29 times. The stable cycling can last 122 times at a limited capacity of 300 mA h g−1. This result indicates that the catalytic performance and structural stability of the cathodes are equally important to achieve a high performance of Li–O2 batteries.
Co-reporter:Yong Zhang;Peiyi Zhu;Liliang Huang;Shichao Zhang;Gaoshao Cao;Xinbing Zhao
Advanced Functional Materials 2015 Volume 25( Issue 3) pp:481-489
Publication Date(Web):
DOI:10.1002/adfm.201402833
Na-ion Batteries have been considered as promising alternatives to Li-ion batteries due to the natural abundance of sodium resources. Searching for high-performance anode materials currently becomes a hot topic and also a great challenge for developing Na-ion batteries. In this work, a novel hybrid anode is synthesized consisting of ultrafine, few-layered SnS2 anchored on few-layered reduced graphene oxide (rGO) by a facile solvothermal route. The SnS2/rGO hybrid exhibits a high capacity, ultralong cycle life, and superior rate capability. The hybrid can deliver a high charge capacity of 649 mAh g−1 at 100 mA g−1. At 800 mA g−1 (1.8 C), it can yield an initial charge capacity of 469 mAh g−1, which can be maintained at 89% and 61%, respectively, after 400 and 1000 cycles. The hybrid can also sustain a current density up to 12.8 A g−1 (≈28 C) where the charge process can be completed in only 1.3 min while still delivering a charge capacity of 337 mAh g−1. The fast and stable Na-storage ability of SnS2/rGO makes it a promising anode for Na-ion batteries.
Co-reporter:Jingyi Cao, Shuangyu Liu, Jian Xie, Shichao Zhang, Gaoshao Cao, and Xinbing Zhao
ACS Catalysis 2015 Volume 5(Issue 1) pp:241
Publication Date(Web):December 2, 2014
DOI:10.1021/cs501392p
We propose a new design of a binder/carbon-free air electrode with tips-bundled Pt/Co3O4 nanowires grown directly on Ni foam substrate. In this design, the side reactions related to binder/carbon are excluded. The presence of Pt not only promotes the formation of the tips-bundled structure of Co3O4 nanowires but also directs the uniform deposition of a fluffy, thin Li2O2 layer only on the periphery of Pt/Co3O4 nanowires. This crystallization habit of Li2O2 makes it easy to decompose upon recharge with reduced side reactions. As a result, Li–O2 batteries with this cathode show low polarization.Keywords: binder/carbon free; cobalt oxide; directed Li2O2 growth; lithium−oxygen batteries; platinum; tips-bundled nanowires
Co-reporter:Guoqing Wang, Liliang Huang, Wei Huang, Jian Xie, Gaohui Du, Shichao Zhang, Peiyi Zhu, Gaoshao Cao and Xinbing Zhao
Nanoscale 2015 vol. 7(Issue 48) pp:20614-20624
Publication Date(Web):12 Nov 2015
DOI:10.1039/C5NR07486J
Despite the recent advancements in Li–O2 (or Li–air) batteries, great challenges still remain to realize high-rate, long-term cycling. In this work, a binder-free, nanostructured RuO2/MnO2 catalytic cathode was designed to realize the operation of Li–O2 batteries at high rates. At a current density as high as 3200 mA g−1 (or ∼1.3 mA cm−2), the RuO2/MnO2 catalyzed Li–O2 batteries with LiI can sustain stable cycling of 170 and 800 times at limited capacities of 1000 and 500 mA h g−1, respectively, with low charge cutoff potentials of ∼4.0 and <3.8 V, respectively. The underlying mechanism of the high catalytic performance of MnO2/RuO2 was also clarified in this work. It was found that with the catalytic effect of RuO2, Li2O2 can crystallize into a thin-sheet form and realize a conformal growth on sheet-like δ-MnO2 at a current density up to 3200 mA g−1, constructing a sheet-on-sheet structure. This crystallization behavior of Li2O2 not only defers the electrode passivation upon discharge but also renders easy decomposition of Li2O2 upon charge, leading to low polarizations and reduced side reactions. This work provides a unique design of catalytic cathodes capable of controlling Li2O2 growth and sheds light on the design of high-rate, long-life Li–O2 batteries with potential applications in electric vehicles.
Co-reporter:Shuangyu Liu, Guoqing Wang, Fangfang Tu, Jian Xie, Hui Ying Yang, Shichao Zhang, Tiejun Zhu, Gaoshao Cao and Xinbing Zhao
Nanoscale 2015 vol. 7(Issue 21) pp:9589-9596
Publication Date(Web):20 Apr 2015
DOI:10.1039/C5NR01344E
A Li–O2 battery works based on the reversible formation and decomposition of Li2O2, which is insulating and highly reactive. Designing a catalytic cathode capable of controlling Li2O2 growth recently became a challenge to overcome this barrier. In this work, we present a new design of catalytic cathode by growing porous Au/δ-MnO2 electrocatalyst directly on a conductive substrate. We found that Au/δ-MnO2 can catalyze the directed growth of Li2O2 into a thin/small form, only inside porous δ-MnO2, and along the surface of δ-MnO2 sheets. We proposed the catalytic mechanism of Au/δ-MnO2, where Au plays a critical role in catalyzing the nucleation, crystallization and conformal growth of Li2O2 on δ-MnO2 sheets. Li–O2 batteries with an Au/δ-MnO2 catalytic cathode showed excellent electrochemical performance due to this favorable Li2O2 growth habit. The battery yielded a high capacity of 10600 mA h g−1 with a low polarization of 0.91 V at 100 mA g−1. Superior cycling stability could be achieved in both capacity-limited (500 mA h g−1, 165 times at 400 mA g−1) and unlimited (ca. 3000 mA h g−1, 50 cycles at 800 mA g−1) modes.
Co-reporter:Longhuan Liao, Hongtao Wang, Hui Guo, Peiyi Zhu, Jian Xie, Chuanhong Jin, Shichao Zhang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2015 vol. 3(Issue 38) pp:19368-19375
Publication Date(Web):14 Aug 2015
DOI:10.1039/C5TA05358G
Fe doping is widely used to improve the electrochemical performance of LiMnPO4 by “implanting” the merits of high rate capability and long cycle life of LiFePO4 into LiMnPO4. Nevertheless, great challenges still remain to obtain high-performance LiFexMn1−xPO4 at a low x value. In this work, we synthesized ultrathin LiFexMn1−xPO4 (x ≤ 0.15) nanoplates by a facile, controllable method. The plate-like LiFexMn1−xPO4 with a small lateral size (40–100 nm) and thickness (10–20 nm) exhibits high electrochemical activity, excellent rate capability and superior cycling stability after carbon coating. At a rate as high as 50C (8.5 A g−1), the LiFe0.15Mn0.85PO4/C composite can still yield a high discharge capacity of 96.2 mA h g−1 where the discharge process can be completed in only 40 s. LiFe0.15Mn0.85PO4/C can sustain a long-term cycling up to 1000 cycles at 10C with a capacity retention close to 70%. The fast and stable cycling ability of LiFexMn1−xPO4 makes it promising for applications in electric vehicles and hybrid electric vehicles.
Co-reporter:Fangfang Tu, Jian Xie, Shichao Zhang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2015 vol. 3(Issue 10) pp:5714-5721
Publication Date(Web):05 Feb 2015
DOI:10.1039/C4TA06850E
Li–O2 (or Li–air) batteries currently represent a hot topic in the field of energy storage and conversion. The electrochemical performance of the Li–O2 battery depends largely on the material and architecture of the catalytic cathode. In this work, we propose a unique design of a binder-free catalytic cathode for Li–O2 batteries. The electrode consists of a novel mushroom-like Au/NiCo2O4 nanohybrid on three-dimensional graphene (3D-G) grown directly on the skeleton of Ni foam. The Au/NiCo2O4/3D-G catalyst exhibits a good catalytic effect for Li–O2 batteries, where Au directs the growth of Li2O2 mainly on the top of mushroom-like Au/NiCo2O4, and induces the crystallization of Li2O2 into the thin-flake or thin-film form that is found to decompose relatively easily compared with the large-particle form upon charging. Mushroom-like NiCo2O4 provides additional catalytic sites and acts as the support for both Au and Li2O2. A Li–O2 battery with the Au/NiCo2O4/3D-G catalyst can deliver a capacity of around 1275 mA h g−1 at 42.5 mA g−1. When the capacity is limited at 510 mA h g−1, the Li–O2 battery can sustain stable cycling up to 40 times.
Co-reporter:Guoqing Wang, Liliang Huang, Shuangyu Liu, Jian Xie, Shichao Zhang, Peiyi Zhu, Gaoshao Cao, and Xinbing Zhao
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 43) pp:23876
Publication Date(Web):October 14, 2015
DOI:10.1021/acsami.5b05250
Lithium–air (Li–air) battery works essentially based on the interfacial reaction of 2Li + O2 ↔ Li2O2 on the catalyst/oxygen-gas/electrolyte triphase interface. Operation of Li–air batteries in ambient air still remains a great challenge despite the recent development, because some side reactions related to moisture (H2O) and carbon dioxide (CO2) will occur on the interface with the formation of some inert byproducts on the surface of the catalyst. In this work, we investigated the effect of H2O and CO2 on the electrochemical performance of Li–air batteries to evaluate the practical operation of the batteries in ambient air. The use of a highly efficient gold/δ-manganese-dioxide (Au/δ-MnO2) catalyst helps to understand the intrinsic mechanism of the effect. We found that H2O has a more detrimental influence than CO2 on the battery performance when operated in ambient air. The battery operated in simulated dry air can sustain a stable cycling up to 200 cycles at 400 mA g–1 with a relatively low polarization, which is comparable with that operated in pure O2. This work provides a possible method to operate Li–air batteries in ambient air by using optimized catalytic electrodes with a protective layer, for example a hydrophobic membrane.Keywords: ambient operation; carbon dioxide; gold/manganese-dioxide; interfacial reactions; lithium−air batteries; moisture
Co-reporter:Hui Guo, Chunyang Wu, Longhuan Liao, Jian Xie, Shichao Zhang, Peiyi Zhu, Gaoshao Cao, and Xinbing Zhao
Inorganic Chemistry 2015 Volume 54(Issue 2) pp:667-674
Publication Date(Web):January 5, 2015
DOI:10.1021/ic5026075
Olivine-type lithium manganese phosphate (LiMnPO4) has been considered as a promising cathode for next-generation Li-ion batteries. Preparation of high-performance LiMnPO4 still remains a great challenge because of its intrinsically low Li-ion/electronic conductivity. In this work, significant performance enhancement of LiMnPO4 has been realized by a controllable acid-engaged morphology tailoring from large spindles into small plates. We find that acidity plays a critical role in altering the morphology of the LiMnPO4 crystals. We also find that size decrease and plate-like morphology are beneficial for the performance improvement of LiMnPO4. Among the plate-like samples, the one with the smallest size shows the best electrochemical performance. After carbon coating, it can deliver high discharge capacities of 104.0 mAh g–1 at 10 C and 85.0 mAh g–1 at 20 C. After 200 cycles at 1 C, it can still maintain a high discharge capacity of 106.4 mAh g–1, showing attractive applications in high-power and high-energy Li-ion batteries.
Co-reporter:Yandong Zhang, Jian Xie, Shichao Zhang, Peiyi Zhu, Gaoshao Cao, Xinbing Zhao
Electrochimica Acta 2015 Volume 151() pp:8-15
Publication Date(Web):1 January 2015
DOI:10.1016/j.electacta.2014.11.009
•A nanohybrid based on ultrafine SnO2 and few-layered rGO has been prepared.•The nanohybrid exhibits excellent electrochemical Na-storage properties.•The rGO supplies combined conducting, buffering and dispersing effects.Na-ion Battery is attractive alternative to Li-ion battery due to the natural abundance of sodium resource. Searching for suitable anode materials is one of the critical issues for Na-ion battery due to the low Na-storage activity of carbon materials. In this work, we synthesized a nanohybrid anode consisting of ultrafine SnO2 anchored on few-layered reduced graphene oxide (rGO) by a facile hydrothermal route. The SnO2/rGO hybrid exhibits a high capacity, long cycle life and good rate capability. The hybrid can deliver a high charge capacity of 324 mAh gSnO2−1 at 50 mA g−1. At 1600 mA g−1 (2.4C), it can still yield a charge capacity of 200 mAh gSnO2−1. After 100 cycles at 100 mA g−1, the hybrid can retain a high charge capacity of 369 mAh gSnO2−1. X-ray photoelectron spectroscopy, ex situ transmission electron microscopy and electrochemical impedance spectroscopy were used to investigate the origin of the excellent electrochemical Na-storage properties of SnO2/rGO.
Co-reporter:Longhuan Liao, Jian Xie, Shichao Zhang, Gaoshao Cao and Xinbing Zhao
RSC Advances 2015 vol. 5(Issue 121) pp:99632-99639
Publication Date(Web):10 Nov 2015
DOI:10.1039/C5RA21264B
Lithium manganese phosphate (LiMnPO4) has been considered as an alternative to lithium iron phosphate (LiFePO4) for next-generation Li-ion battery cathodes because of its higher working voltage. However, facile preparation methods for high-performance LiMnPO4 are still lacking. In this work, we propose a facile route to prepare nano-LiMnPO4 (30–50 nm) by using citric acid (CA) as a surfactant. The addition of a small amount of CA in the precursor leads to an obvious size reduction of LiMnPO4. After carbon-coating, nano-LiMnPO4 exhibits excellent rate capability and long cycle life at high rates because of the small size and uniform/thin carbon coating. At a high rate of up to 20C (3.4 A g−1), LiMnPO4/C can still deliver a high discharge capacity of 96.6 mA h g−1. LiMnPO4/C also exhibits long cycle life with ∼70% capacity retained after 500 cycles at 10C. The excellent electrochemical performance of LiMnPO4/C makes it an attractive cathode in high-power and high-energy Li-ion batteries.
Co-reporter:Shuangyu Liu;Yunguang Zhu;Ying Huo;Hui Ying Yang;Tiejun Zhu;Gaoshao Cao;Xinbing Zhao;Shichao Zhang
Advanced Energy Materials 2014 Volume 4( Issue 9) pp:
Publication Date(Web):
DOI:10.1002/aenm.201301960
A challenge still remains to develop high-performance and cost-effective air electrode for Li-O2 batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) despite recent advances in this field. In this work, a new design of binder-free air electrode composed of three-dimensional (3D) graphene (G) and flower-like δ-MnO2 (3D-G-MnO2) has been proposed. In this design, graphene and δ-MnO2 grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li-O2 batteries with 3D-G-MnO2 electrode can yield a high discharge capacity of 3660 mAh g−1 at 0.083 mA cm−2. The battery can sustain 132 cycles at a capacity of 492 mAh g−1 (1000 mAh gcarbon −1) with low overpotentials under a high current density of 0.333 mA cm−2. A high average energy density of 1350 Wh Kg−1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D-G-MnO2 makes it an attractive air electrode for high-performance Li-O2 batteries.
Co-reporter:Shuangyu Liu, Jian Xie, Haibo Li, Ye Wang, Hui Ying Yang, Tiejun Zhu, Shichao Zhang, Gaoshao Cao and Xinbing Zhao
Journal of Materials Chemistry A 2014 vol. 2(Issue 42) pp:18125-18131
Publication Date(Web):02 Sep 2014
DOI:10.1039/C4TA03192J
The rapid development of microelectronic devices has stimulated an increasing demand for micro-energy storage devices, typically, micro-supercapacitors (MSCs). Despite recent advances, the fabrication of MSCs using a facile, scalable and inexpensive method still remains challenging. In this work, we use a facile screen printing technique to fabricate flexible all-solid-state MSCs using N-doped reduced graphene oxide (rGO) as the electrode material. The effective area of MSCs and the thickness of the active material are only 0.396 cm2 and 10 μm, respectively. The MSCs can deliver a high specific areal capacitance of 3.4 mF cm−2, which is among the high values of graphene-based materials for all-solid-state MSCs reported so far. Easy fabrication and good performance make MSCs promising on-chip energy storage devices.
Co-reporter:Yandong Zhang, Jian Xie, Tiejun Zhu, Gaoshao Cao, Xinbing Zhao, Shichao Zhang
Journal of Power Sources 2014 Volume 247() pp:204-212
Publication Date(Web):1 February 2014
DOI:10.1016/j.jpowsour.2013.08.096
•We synthesize Sb/graphene nanohybrid by an in situ one-pot solvothermal route.•The nanohybrid exhibits improved Li and Na-storage properties than bare Sb.•The graphene offers buffering, conducting, and immobilizing effects for Sb.A Sb/graphene nanohybrid has been synthesized by a facile in situ solvothermal route using SbCl3 and graphite oxide as the precursors and NaBH4 as the reducing agent. Microstructural observation reveals the sheet-like nanostructure consisting of Sb nanocrystals (50–100 nm) attached on few-layer graphene nanosheets. The in situ introduced graphene uniformly disperses the Sb nanocrystals, while the attached Sb nanocrystals hinder the restacking of the graphene nanosheets. The introduction of graphene remarkably improves the electrochemical Li and Na-storage properties of Sb due to the combined buffering, confining and conducting effects of graphene. The underlying mechanism for the enhanced Li and Na-storage properties has been investigated by chemical diffusion coefficient and electrochemical impedance spectroscopy measurement.
Co-reporter:Guoqing Wang, Jian Xie, Chunyang Wu, Shichao Zhang, Gaoshao Cao, Xinbing Zhao
Journal of Power Sources 2014 Volume 265() pp:118-124
Publication Date(Web):1 November 2014
DOI:10.1016/j.jpowsour.2014.04.125
•We synthesize submicron LiNi0.5Mn1.5O4 by a facile route.•LiNi0.5Mn1.5O4 shows excellent rate performance and cycling stability.•LiNi0.5Mn1.5O4–MCMB cells show promising high-energy-density applications.Lithium nickel manganese oxide (LiNi0.5Mn1.5O4) shows promising applications in next-generation Li-ion batteries due to its high working voltage. In this work, submicron LiNi0.5Mn1.5O4 has been synthesized by a facile solid-phase route and its electrochemical performance has been investigated in both half cells and full cells using mesocarbon microbeads as anodes. In LiNi0.5Mn1.5O4–Li cells, LiNi0.5Mn1.5O4 shows excellent rate performance and high-rate cycling stability. At 20 C, LiNi0.5Mn1.5O4 can yield a discharge capacity of 105.8 mAh g−1. After 1400 cycles at 1 C, a discharge capacity of around 80 mAh g−1 can be still delivered. The LiNi0.5Mn1.5O4-limited full cells exhibit a working voltage of around 4.5 V and a discharge capacity of 90.0 mAh g−1 after 120 cycles at 1 C. The excellent electrochemical performance of LiNi0.5Mn1.5O4 can be attributed to a combination of submicron size, durability of Mn3+ at high rates and small-size induced protective film.
Co-reporter:Qin Pan, Jian Xie, Tiejun Zhu, Gaoshao Cao, Xinbing Zhao, and Shichao Zhang
Inorganic Chemistry 2014 Volume 53(Issue 7) pp:3511-3518
Publication Date(Web):March 19, 2014
DOI:10.1021/ic402948s
Preparation of two-dimensional (2D) graphene-like materials is currently an emerging field in materials science since the discovery of single-atom-thick graphene prepared by mechanical cleavage. In this work, we proposed a new method to prepare 2D NiS, where reduced graphene oxide (rGO) was found to induce the recrystallization of NiS from nanorods to nanosheets in a hydrothermal process. The process and mechanism of recrystallization have been clarified by various characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) mapping, and X-ray photoelectron spectroscopy (XPS). The characterization of ex situ NiS/rGO products by SEM and EDS mapping indicates that the recrystallization of NiS from nanorods to nanosheets is realized actually through an exfoliation process, while the characterization of in situ NiS/rGO products by SEM, TEM, and EDS mapping reveals the exfoliation process. The XPS result demonstrates that hydrothermally assisted chemical bonding occurs between NiS and rGO, which induces the exfoliation of NiS nanorods into nanosheets. The obtained NiS/rGO composite shows promising Na-storage properties.
Co-reporter:Jian Xie, Guoqing Wang, Ying Huo, Shichao Zhang, Gaoshao Cao, Xinbing Zhao
Electrochimica Acta 2014 Volume 135() pp:94-100
Publication Date(Web):20 July 2014
DOI:10.1016/j.electacta.2014.05.012
•We synthesize nanostructured Si spheres by controllable magnesiothermic reduction.•Shape-preserving conversion from monodisperse spheric SiO2 to Si has been realized. Nanostructured Si/C composites exhibit a promising electrochemical performance.In this work, nanostructured, monodisperse Si spheres have been prepared by a facile, controllable magnesiothermic reduction method using monodisperse SiO2 spheres as the precursor. The reaction conditions for magnesiothermic reduction have been optimized, yielding desired product and byproduct. Carbon coating on Si nanocrystals is performed by an easy chemical vapor deposition (CVD) method. The effect of carbon coating on electrochemical performance of Si is investigated. The results show that the original monodisperse spheric morphology of SiO2 can be preserved during magnesiothermic reduction and the cycling stability of Si can be enhanced by carbon coating. This work provides a facile, scalable method to synthesize nanostructured Si and Si/C composites.
Co-reporter:Jian Xie, Guoqing Wang, Ying Huo, Shichao Zhang, Gaoshao Cao and Xinbing Zhao
New Journal of Chemistry 2014 vol. 38(Issue 9) pp:4177-4181
Publication Date(Web):13 Jun 2014
DOI:10.1039/C4NJ00752B
In this work, nanostructured, hollow Si has been prepared by a combined template direction and magnesiothermic reduction reaction. Fe2O3 nanorings are used as templates to synthesize hollow SiO2 nanorings, the precursor for hollow Si. After carbon coating by chemical vapor deposition, the hollow Si–C composite shows high capacity and stable cycling due to its unique hollow structure and nanoscale size that endow Si–C with enhanced electrode kinetics. This work provides a controllable method to synthesize hollow nano Si and Si–C nanocomposites as high-performance anodes for Li-ion batteries.
Co-reporter:Bin Feng, Jian Xie, Chen Dong, Shichao Zhang, Gaoshao Cao and Xinbing Zhao
RSC Advances 2014 vol. 4(Issue 34) pp:17902-17907
Publication Date(Web):07 Apr 2014
DOI:10.1039/C4RA01985G
In this work, we developed a green and facile approach to prepare graphene by the reduction of graphite oxide (GO) using two Chinese medicinal herbs: inulin and Chinese wolfberry. The reduced products were systematically characterized by UV-visible absorption spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. These results provided convincing evidence of the removal of oxygen-containing groups from GO to form few-layered graphene after the reduction reaction. Simultaneously, nitrogen and sulfur co-doping were achieved under a relatively low temperature (90 °C). The reduction mechanism of GO and N, S bonding configurations in graphene were also proposed.
Co-reporter:Jian Xie, Wentao Song, Gaoshao Cao, Tiejun Zhu, Xinbing Zhao and Shichao Zhang
RSC Advances 2014 vol. 4(Issue 15) pp:7703-7709
Publication Date(Web):09 Jan 2014
DOI:10.1039/C3RA46904B
A ZnFe2O4-nanocrystals/graphene-nanosheets (ZnFe2O4/G) nanohybrid has been prepared by a facile in situ hydrothermal route using Zn(NO3)2·6H2O, Fe(NO3)3·6H2O and graphite oxide (GO) as the precursors. Ultrafine ZnFe2O4 nanocrystals (below 10 nm) are confined by the few-layer graphene sheets reduced from GO, forming a unique sheet-like hybrid. In this structure, the direct restacking of the hydrophobic graphene sheets is refrained by loading ZnFe2O4 nanocrystals as the spacers and the aggregation of ZnFe2O4 nanocrystals is inhibited by the dispersing and confining effects of the graphene sheets. ZnFe2O4/G shows excellent rate capability and high-rate cycling stability for lithium storage. It also shows a high capacity when used as an anode for a ZnFe2O4/G–LiFePO4/C full cell.
Co-reporter:Peiyi Zhu, Shuangyu Liu, Jian Xie, Shichao Zhang, Gaoshao Cao, Xinbing Zhao
Journal of Materials Science & Technology 2014 Volume 30(Issue 11) pp:1078-1083
Publication Date(Web):November 2014
DOI:10.1016/j.jmst.2014.08.009
•We synthesized NiFe2O4/rGO nanohybrid by a facile one-pot hydrothermal route.•NiFe2O4/rGO shows improved rate performance and cycling stability than NiFe2O4.•The improved performance is due to the two-dimensional rGO and hybrid structure.In this work, a facile, one-pot route has been applied to synthesize nanohybrids based on mixed oxide NiFe2O4 and reduced graphene oxide (rGO). The hybrid is constructed by nanosized NiFe2O4 crystals confined by few-layered rGO sheets. The formation mechanism and microstructure of the hybrids have been clarified by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical tests show that the performance of NiFe2O4 can be considerably improved by rGO incorporation. The performance improvement can be attributed to the two-dimensional conductive channels and the unique hybrid structure rGO constructed. The easy synthesis and good electrochemical performance of NiFe2O4/rGO hybrid make it a promising anode material for Li-ion batteries.
Co-reporter:Shuangyu Liu, Jian Xie, Qingmei Su, Gaohui Du, Shichao Zhang, Gaoshao Cao, Tiejun Zhu, Xinbing Zhao
Nano Energy 2014 Volume 8() pp:84-94
Publication Date(Web):September 2014
DOI:10.1016/j.nanoen.2014.06.001
•We fabricated an all-solid-state nano lithium battery MnFe2O4/GNS–Li2O–Li.•In situ TEM was used to investigate the electrochemical reaction of MnFe2O4 with Li.•Macroscopic electrochemical property was correlated to microscopic characterization.In this work, we fabricated an all-solid-state nano lithium battery MnFe2O4/graphene–Li2O–Li to understand the electrochemical Li-storage mechanism and performance of MnFe2O4 using in situ transmission electron microscopy (TEM) technique. We found that single-crystalline MnFe2O4 is converted into polycrystalline Li2O/Mn/Fe with large volume expansion upon discharge and subsequently into polycrystalline MnO/Fe3O4 with volume shrinkage upon charge. Reversible conversion between MnO/Fe3O4 and Li2O/Mn/Fe occurs during the following cycles with small volume changes. We also found that both MnO/Fe3O4 and Li2O/Mn/Fe can be tightly confined by graphene despite the volume change and particle pulverization, and that free space that buffers the volume changes still exists even at deep lithiation state. In situ TEM characterization also indicates that graphene is a good conductor for both Li ion and electrons. The combined conducting, buffering and confining effects of graphene revealed by in situ TEM characterization can well explain the role it plays in improving the electrochemical properties of MnFe2O4.
Co-reporter:Bin Feng, Jian Xie, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2013 vol. 1(Issue 42) pp:13111-13119
Publication Date(Web):06 Sep 2013
DOI:10.1039/C3TA13202A
Nanostructuring and second phase incorporation are considered to be promising ways of enhancing the thermoelectric performance of bulk materials. Here, a design principle is proposed which combines these two methods for improving the thermoelectric performance of p-type CoSb3 by fabricating a CoSb3/graphene (CoSb3/G) nanocomposite, where a second phase, graphene, is introduced in the nanostructured CoSb3 matrix via an in situ one-pot solvothermal route. In addition, CoSb3/G bulk materials were prepared by hot pressing the solvothermally synthesized CoSb3/G powder. It was found that addition of a small amount of graphene can drastically enhance the electrical conductivity due to the increase in both carrier concentration and mobility. In addition, the well dispersed graphene in the nanostructured CoSb3 matrix also contributes to the low lattice thermal conductivity. A dimensionless figure of merit ZT = 0.61 at 800 K has been obtained for the CoSb3/G nanocomposite, which is about a 130% improvement over that of graphene-free CoSb3 (∼0.26).
Co-reporter:Shuangyu Liu, Xiang Lu, Jian Xie, Gaoshao Cao, Tiejun Zhu, and Xinbing Zhao
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 5) pp:1588
Publication Date(Web):February 19, 2013
DOI:10.1021/am302124f
A SnS2/graphene (SnS2/G) hybrid was synthesized by a facile one-step solvothermal route using graphite oxide, sodium sulfide, and SnCl4·5H2O as the starting materials. The formation of SnS2 and the reduction of graphite oxide occur simultaneously. Ultrathin SnS2 nanoplates with a lateral size of 5–10 nm are anchored on graphene nanosheets with a preferential (001) orientation, forming a unique plate-on-sheet structure. The electrochemical tests showed that the nanohybrid exhibits a remarkably enhanced cycling stability and rate capability compared with bare SnS2. The excellent electrochemical properties of SnS2/G could be ascribed to the in situ introduced graphene matrix which offers two-dimensional conductive networks, disperses and immobilizes SnS2 nanoplates, buffers the volume changes during cycling, and directs the growth of SnS2 nanoplates with a favorable orientation.Keywords: anode; c-axis orientation; graphene; Li-ion batteries; plate-on-sheet; tin sulfide;
Co-reporter:Wentao Song, Jian Xie, Wenyue Hu, Shuangyu Liu, Gaoshao Cao, Tiejun Zhu, Xinbing Zhao
Journal of Power Sources 2013 Volume 229() pp:6-11
Publication Date(Web):1 May 2013
DOI:10.1016/j.jpowsour.2012.11.090
A Zn2SnO4-nanocrystals/graphene-nanosheets (Zn2SnO4/G) nanohybrid has been prepared by a facile in situ hydrothermal route using SnCl4⋅5H2O, ZnCl2 and graphite oxide (GO) as the precursors and N2H4⋅H2O as the mineralizer and reducing agent. The formation of Zn2SnO4 and the reduction GO occur simultaneously during the hydrothermal process. The Zn2SnO4 nanocrystals are uniformly dispersed and immobilized by the graphene nanosheets reduced from GO. The direct restacking of the hydrophobic graphene sheets is inhibited by loading Zn2SnO4 nanocrystals as the spacers. Zn2SnO4/G shows an improved electrochemical performance than bare Zn2SnO4 due to the conducting, dispersing and immobilizing effects of graphene.Highlights► We synthesize Zn2SnO4-nanocrystal/graphene-nanosheet hybrid by an in situ route. ► The hybrid exhibits an improved electrochemical performance than bare Zn2SnO4. ► The graphene offers buffering, conducting, and immobilizing effects for Zn2SnO4.
Co-reporter:Qin Pan, Jian Xie, Shuangyu Liu, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
RSC Advances 2013 vol. 3(Issue 12) pp:3899-3906
Publication Date(Web):06 Dec 2012
DOI:10.1039/C2RA22410K
A NiS/graphene (NiS/G) nanohybrid has been synthesized by a facile in situ one-pot hydrothermal route using graphite oxide, thiourea, NiCl2·4H2O and sodium citrate as the raw materials. The growth of NiS nanosheets and the reduction of graphite oxide occur simultaneously during the hydrothermal reactions. The hybrid exhibits a unique sheet-on-sheet structure, where ultrathin NiS sheets (below 5 nm) are anchoring on few-layer (below 8 layers) graphene sheets. The electrochemical measurements indicate that the NiS/G hybrid exhibits remarkably improved Li-storage properties compared with bare NiS, due to the ultrathin feature of the NiS sheets, unique sheet-on-sheet structure of the hybrid, and the combined conducting, buffering and confining effects of the in situ introduced graphene nanosheets.
Co-reporter:Bin Feng, Jian Xie, Gao-Shao Cao, Tie-Jun Zhu and Xin-Bing Zhao
New Journal of Chemistry 2013 vol. 37(Issue 2) pp:474-480
Publication Date(Web):13 Nov 2012
DOI:10.1039/C2NJ40894E
In this work, we succeeded in the synthesis of a CoSn2-nanocrystals/graphene-nanosheets (CoSn2/G) hybrid by a facile in situ one-pot solvothermal route. X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectra results revealed the formation of CoSn2 and the reduction of graphite oxide (GO) to graphene during the one-pot process. Transmission electron microscopy observation indicated that the spherical CoSn2 nanocrystals, with a uniform size of 2–4 nm, are anchored on graphene. The electrochemical tests showed that the CoSn2/G hybrid exhibits obviously improved electrochemical properties compared to the bare Co–Sn alloy prepared by a similar route in the absence of GO, even though the content of graphene is only 7.2 wt%. The enhancement in the electrochemical properties could be attributed to the introduction of graphene that not only constructs two-dimensional conductive networks but also disperses and confines the CoSn2 nanocrystals, in addition to the buffering effect for the large volume changes.
Co-reporter:Jian Xie;Cheng-Yue Sun;Tie-Jun Zhu
Journal of Solid State Electrochemistry 2013 Volume 17( Issue 10) pp:2589-2594
Publication Date(Web):2013 October
DOI:10.1007/s10008-013-2153-9
LiMn2O4 microcubes with a size of 10–15 μm have been synthesized by a facile self-templating route starting from cubic MnCO3. The LiMn2O4 microcubes exhibit a hierarchical structure, where the cubes are stacked from parallel plates with a thickness of 200 nm, where each plate is composed of interconnected nanoparticles with a size of around 200 nm. The cubic LiMn2O4 shows excellent rate capability and high-rate cycling stability. At 10 C, it can yield a discharge capacity of 108 mAh g−1. A discharge capacity of 88 mAh g−1 can be retained after 100 cycles at 10 C. The excellent electrochemical performance makes it a promising cathode for high-power Li-ion batteries.
Co-reporter:Shuangyu Liu, Jian Xie, Chengcheng Fang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2012 vol. 22(Issue 37) pp:19738-19743
Publication Date(Web):07 Aug 2012
DOI:10.1039/C2JM34019D
A CoFe2O4-nanocrystal/graphene-nanosheet (CFO/GS) nanohybrid has been synthesized by a facile in situ solvothermal route and has been investigated as a promising high-performance anode material for Li-ion batteries. The crystal size of CoFe2O4 can be controlled to 10–20 nm by pre-treating the precursors before the solvothermal reactions. The method for synthesizing the CFO/GS hybrid can be extended to synthesize MFe2O4/graphene (MFe2O4/G, M = Mn and Ni) hybrids. The CFO/GS hybrid exhibits superior cycling stability and rate capability compared to bare CoFe2O4. The improved electrochemical performance can be attributed to a combination of the conducting, confining and dispersing effects of graphene.
Co-reporter:Yunxiao Zheng, Jian Xie, Shuangyu Liu, Wentao Song, Gaoshao Cao, Tiejun Zhu, Xinbing Zhao
Journal of Power Sources 2012 Volume 202() pp:276-283
Publication Date(Web):15 March 2012
DOI:10.1016/j.jpowsour.2011.11.049
In this work, a CoSb-nanocrystal/graphene hybrid nanostructure has been synthesized by a facile one-pot in situ solvothermal route. X-ray diffraction and X-ray photoelectron spectroscopy analyses show that the formation of CoSb alloy (CoSb or CoSb2) and the reduction of graphite oxide occur simultaneously during the one-pot solvothermal process. Scanning electron microscopy and transmission electron microscopy observations indicate that quasi-spheric CoSb (or CoSb2) nanoparticles with a size of 10–30 nm are uniformly anchored on graphene, forming a unique layered structure. The presence of graphene prevents the nanoparticles from aggregating. The attached alloy nanoparticles also hinder the restacking of the graphene sheets. The electrochemical measurements have shown that CoSb-nanocrystal/graphene nanocomposites exhibit improved electrochemical Li-storage properties compared with bare CoSb alloy, due to the combined buffering, confining and conducting effects of the in situ introduced graphene.Highlights► We synthesize CoSb-nanocrystal/graphene composites by an in situ one-pot route. ► The composite can assemble into a novel layered hybrid nanostructure. ► The hybrid exhibits improved electrochemical properties than bare alloys. ► The graphene offers combined buffering, conducting, and confining effects.
Co-reporter:Wentao Song, Jian Xie, Shuangyu Liu, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
New Journal of Chemistry 2012 vol. 36(Issue 11) pp:2236-2241
Publication Date(Web):02 Aug 2012
DOI:10.1039/C2NJ40534B
A nanohybrid based on ZnFe2O4 nanospheres and graphene nanosheets (ZnFe2O4/G) has been synthesized by a facile one-pot in situ solvothermal route. The results show that the formation of ZnFe2O4 and the reduction of graphite oxide take place simultaneously during the solvothermal reactions. Spheric ZnFe2O4 nanoparticles with a size of 100–200 nm are confined in between the graphene sheets, forming a unique hybrid nanostructure. The electrochemical measurements have shown that the ZnFe2O4/G hybrid exhibits improved electrochemical Li-storage properties compared with bare ZnFe2O4, due to the combined buffering, confining and conducting effects of the in situ introduced graphene nanosheets.
Co-reporter:J. Xie, Yunxiao Zheng, Shuangyu Liu, Gaoshao Cao, Xinbing Zhao
Journal of Materials Science & Technology 2012 Volume 28(Issue 3) pp:275-279
Publication Date(Web):March 2012
DOI:10.1016/S1005-0302(12)60053-X
Co-reporter:Jian Xie;Wen-tao Song;Gao-shao Cao
International Journal of Minerals, Metallurgy, and Materials 2012 Volume 19( Issue 6) pp:542-548
Publication Date(Web):2012 June
DOI:10.1007/s12613-012-0593-3
A Sb-Fe-carbon-fiber (CF) composite was prepared by a chemical vapor deposition (CVD) method with in situ growth of CFs using Sb2O3/Fe2O3 as the precursor and acetylene (C2H2) as the carbon source. The Sb-Fe-CF composite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), and its electrochemical performance was investigated by galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The Sb-Fe-CF composite shows a better cycling stability than the Sb-amorphous-carbon composite prepared by the same CVD method but using Sb2O3 as the precursor. Improvements in cycling stability of the Sb-Fe-CF composite can be attributed to the formation of three-dimensional network structure by CFs, which can connect Sb particles firmly. In addition, the CF layer can buffer the volume change effectively.
Co-reporter:Yuan-Li Ding, Xin-Bing Zhao, Jian Xie, Gao-Shao Cao, Tie-Jun Zhu, Hong-Ming Yu and Cheng-Yue Sun
Journal of Materials Chemistry A 2011 vol. 21(Issue 26) pp:9475-9479
Publication Date(Web):23 May 2011
DOI:10.1039/C1JM10924C
Double-shelled hollow microspheres of LiMn2O4 were prepared by a facile self-template method. The inner and outer shells of the obtained microspheres are composed of nanoparticles with diameters ranging between 200–400 nm. Galvanostatic charge/discharge cycling shows that this material delivers a discharge capacity of 127 mAh g−1 at C/10 rate and a capacity retainability of 80% after 800 cycles at 5 C rate, revealing a high reversible capacity, superior rate capability and excellent cycling stability under high rates. The improved performance is attributed to the short Li+ ion diffusion lengths in the nanobuilding blocks and the void core and space between the inner and outer shells to accommodate the volume expansion/contraction during Li+ ions insertion/extraction processes.
Co-reporter:J. Xie, N. Imanishi, A. Hirano, Y. Takeda, O. Yamamoto, X.B. Zhao, G.S. Cao
Thin Solid Films 2011 Volume 519(Issue 10) pp:3373-3377
Publication Date(Web):1 March 2011
DOI:10.1016/j.tsf.2010.12.092
Amorphous Zn and ZnO thin films have been prepared by radio frequency magnetron sputtering on Cu substrates and have been characterized by X-ray diffraction, scanning electron microscope, and Raman spectroscopy. The electrochemical performance of the thin films has been studied by galvanostatic cycling and cyclic voltammetry. The voltage dependence of Li-ion chemical diffusion coefficients, D˜Li, of the films has been determined by galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). It is found that the amorphous Zn and ZnO films exhibit almost the same D˜Li values ranging from 10− 14 to 10−12 cm2 s− 1 and similar Li-ion transport characteristics determined both by GITT and by EIS methods.
Co-reporter:J. Xie, N. Imanishi, T. Zhang, A. Hirano, Y. Takeda, O. Yamamoto
Journal of Power Sources 2010 Volume 195(Issue 17) pp:5780-5783
Publication Date(Web):1 September 2010
DOI:10.1016/j.jpowsour.2010.03.040
Amorphous LiCo1/3Mn1/3Ni1/3O2 thin films were deposited on the NASICON-type Li-ion conducting glass ceramics, Li1+x+yAlxTi2−xSiyP3−yO12 (LATSP), by radio frequency (RF) magnetron sputtering below 130 °C. The amorphous films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Li/PEO18–Li(CF3SO2)2N/LATSP/LiCo1/3Mn1/3Ni1/3O2/Au all-solid-state cells were fabricated to investigate the electrochemical performance of the amorphous films. It was found that the low-temperature deposited amorphous cathode film shows a high discharge voltage and a high discharge capacity of around 130 mAh g−1.
Co-reporter:J. Xie, N. Imanishi, T. Zhang, A. Hirano, Y. Takeda, O. Yamamoto, X.B. Zhao, G.S. Cao
Journal of Power Sources 2010 Volume 195(Issue 24) pp:8341-8346
Publication Date(Web):15 December 2010
DOI:10.1016/j.jpowsour.2010.06.066
LiNi0.5Mn0.5O2 thin films have been deposited on the NASICON-type glass ceramics, Li1+x+yAlxTi2−xSiyP3−yO12 (LATSP), by radio frequency (RF) magnetron sputtering followed by annealing. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. All-solid-state Li/PEO18-Li(CF3SO2)2N/LATSP/LiNi0.5Mn0.5O2/Au cells are fabricated using the LiNi0.5Mn0.5O2 thin films and the LATSP electrolyte. The electrochemical performance of the cells is investigated by galvanostatic cycling, cyclic voltammetry (CV), potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectroscopy (EIS). Interfacial reactions between LiNi0.5Mn0.5O2 and LATSP occur at a temperature as low as 300 °C with the formation of Mn3O4, resulting in an increased obstacle for Li-ion diffusion across the LiNi0.5Mn0.5O2/LATSP interface. The electrochemical performance of the cells is limited by the interfacial resistance between LATSP and LiNi0.5Mn0.5O2 as well as the Li-ion diffusion kinetics in LiNi0.5Mn0.5O2 bulk.
Co-reporter:J. Xie, N. Imanishi, T. Zhang, A. Hirano, Y. Takeda, O. Yamamoto, G.S. Cao, X.B. Zhao
Electrochimica Acta 2010 Volume 55(Issue 19) pp:5440-5445
Publication Date(Web):30 July 2010
DOI:10.1016/j.electacta.2010.04.095
Amorphous LiCoO2 thin films were deposited on the NASICON-type glass ceramics, Li1+x+yAlxTi2−xSiyP3−yO12 (LATSP), by radio frequency (RF) magnetron sputtering below 180 °C. The as-deposited LiCoO2 thin films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscope. All-solid-state Li/PEO18–Li (CF3SO2)2N/LATSP/LiCoO2/Au cells were fabricated using the amorphous film. The electrochemical performance of the cells was investigated by galvanostatic cycling, cyclic voltammetry, potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. It was found that the amorphous LiCoO2 thin film shows a promising electrochemical performance, making it a potential application in microbatteries for microelectronic devices.
Co-reporter:J. Xie, N. Imanishi, A. Hirano, Y. Takeda, O. Yamamoto, X.B. Zhao, G.S. Cao
Solid State Ionics 2010 Volume 181(35–36) pp:1611-1615
Publication Date(Web):9 November 2010
DOI:10.1016/j.ssi.2010.09.006
Poorly crystallized Sn, SnO and amorphous SnO2 thin films have been prepared by radio frequency magnetron sputtering on Cu substrates and have been characterized by X-ray diffraction, scanning electron microscope and Raman spectra. The electrochemical performance of the thin films has been studied by galvanostatic cycling and cyclic voltammetry. The apparent Li-ion chemical diffusion coefficients, D̃Li, of the films have been determined by galvanostatic intermittent titration technique (GITT). It is found that the D̃Li values by GITT are in the range of 10− 16 to 10− 14 cm2 s− 1 for the metallic Sn film and 10− 15 to 10− 13 cm2 s− 1 for the tin oxide films. The improved Li-ion diffusion rate in the oxide films than in the metal film is due to its unique microstructure formed during the first cycle, namely, a uniform dispersion of LiδSn (0 ≤ δ ≤ 4.4) in the Li2O matrix.
Co-reporter:J. Xie, X.B. Zhao, G.S. Cao, J.P. Tu
Journal of Power Sources 2007 Volume 164(Issue 1) pp:386-389
Publication Date(Web):10 January 2007
DOI:10.1016/j.jpowsour.2006.09.094
A nanostructured amorphous Co3Sn2 intermetallic compound was prepared by a solvothermal route. The microstructure and the electrochemical performance were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), galvanostatic cycling, and ex situ XRD. It was found that the as-prepared material is in nanoscale and is amorphous. The amorphous Co3Sn2 shows a first specific capacity of 363 mA h g−1 compared to 92 mA h g−1 for the crystalline one prepared by annealing the amorphous material. Ex situ XRD investigation shows that the amorphous Co3Sn2 undergoes a crystallization process during cycling, which leads to the capacity fade.
Co-reporter:Fangfang Tu, Qiannan Wang, Jian Xie, Gaoshao Cao, Shichao Zhang, Jiangwei Wang, Scott X. Mao, Xinbing Zhao, Hui Ying Yang
Energy Storage Materials (January 2017) Volume 6() pp:164-170
Publication Date(Web):1 January 2017
DOI:10.1016/j.ensm.2016.11.003
Li–O2 batteries recently have attracted intensive research interest because of the rather high energy density. The electrochemical performance of Li–O2 batteries, however, is largely limited by the insulating and reactive Li2O2, which necessitates a renovation on the design of catalytic cathodes. In this work, we propose a unique MnO2/carbon submicron tube (MnO2/CST) array-type catalytic cathode capable of controlling Li2O2 growth spatially and structurally. The high catalytic activity of ultrathin MnO2 nanosheets enables conformal growth of thin-layered Li2O2 on the MnO2 sheets, which relieves or defers electrode deactivation upon discharge and renders easy catalytic decomposition of Li2O2 upon charge. In situ transmission electron microscopy characterization confirms the presence of Li2O2 on discharged MnO2/CST and reveals the phase transition and morphology changes upon charge. The array-type architecture of the catalytic cathode facilitates barrier-free transportation of oxygen gas and Li ions. The absence of polymer binder and the reduced carbon exposure to Li2O2 (or LiO2) exclude or minimize the parasitic reactions related to binder and carbon. As a result, Li–O2 cells with MnO2/CST catalytic cathode exhibit superior cycling stability and low polarization. At 800 mA g–1, the cell can sustain a stable cycling of over 300 cycles at a limited capacity of 1000 mAh g–1.Download high-res image (219KB)Download full-size image
Co-reporter:Fangfang Tu, Jian Xie, Shichao Zhang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 10) pp:NaN5721-5721
Publication Date(Web):2015/02/05
DOI:10.1039/C4TA06850E
Li–O2 (or Li–air) batteries currently represent a hot topic in the field of energy storage and conversion. The electrochemical performance of the Li–O2 battery depends largely on the material and architecture of the catalytic cathode. In this work, we propose a unique design of a binder-free catalytic cathode for Li–O2 batteries. The electrode consists of a novel mushroom-like Au/NiCo2O4 nanohybrid on three-dimensional graphene (3D-G) grown directly on the skeleton of Ni foam. The Au/NiCo2O4/3D-G catalyst exhibits a good catalytic effect for Li–O2 batteries, where Au directs the growth of Li2O2 mainly on the top of mushroom-like Au/NiCo2O4, and induces the crystallization of Li2O2 into the thin-flake or thin-film form that is found to decompose relatively easily compared with the large-particle form upon charging. Mushroom-like NiCo2O4 provides additional catalytic sites and acts as the support for both Au and Li2O2. A Li–O2 battery with the Au/NiCo2O4/3D-G catalyst can deliver a capacity of around 1275 mA h g−1 at 42.5 mA g−1. When the capacity is limited at 510 mA h g−1, the Li–O2 battery can sustain stable cycling up to 40 times.
Co-reporter:Yuan-Li Ding, Xin-Bing Zhao, Jian Xie, Gao-Shao Cao, Tie-Jun Zhu, Hong-Ming Yu and Cheng-Yue Sun
Journal of Materials Chemistry A 2011 - vol. 21(Issue 26) pp:NaN9479-9479
Publication Date(Web):2011/05/23
DOI:10.1039/C1JM10924C
Double-shelled hollow microspheres of LiMn2O4 were prepared by a facile self-template method. The inner and outer shells of the obtained microspheres are composed of nanoparticles with diameters ranging between 200–400 nm. Galvanostatic charge/discharge cycling shows that this material delivers a discharge capacity of 127 mAh g−1 at C/10 rate and a capacity retainability of 80% after 800 cycles at 5 C rate, revealing a high reversible capacity, superior rate capability and excellent cycling stability under high rates. The improved performance is attributed to the short Li+ ion diffusion lengths in the nanobuilding blocks and the void core and space between the inner and outer shells to accommodate the volume expansion/contraction during Li+ ions insertion/extraction processes.
Co-reporter:Shuangyu Liu, Jian Xie, Chengcheng Fang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2012 - vol. 22(Issue 37) pp:NaN19743-19743
Publication Date(Web):2012/08/07
DOI:10.1039/C2JM34019D
A CoFe2O4-nanocrystal/graphene-nanosheet (CFO/GS) nanohybrid has been synthesized by a facile in situ solvothermal route and has been investigated as a promising high-performance anode material for Li-ion batteries. The crystal size of CoFe2O4 can be controlled to 10–20 nm by pre-treating the precursors before the solvothermal reactions. The method for synthesizing the CFO/GS hybrid can be extended to synthesize MFe2O4/graphene (MFe2O4/G, M = Mn and Ni) hybrids. The CFO/GS hybrid exhibits superior cycling stability and rate capability compared to bare CoFe2O4. The improved electrochemical performance can be attributed to a combination of the conducting, confining and dispersing effects of graphene.
Co-reporter:Bin Feng, Jian Xie, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2013 - vol. 1(Issue 42) pp:NaN13119-13119
Publication Date(Web):2013/09/06
DOI:10.1039/C3TA13202A
Nanostructuring and second phase incorporation are considered to be promising ways of enhancing the thermoelectric performance of bulk materials. Here, a design principle is proposed which combines these two methods for improving the thermoelectric performance of p-type CoSb3 by fabricating a CoSb3/graphene (CoSb3/G) nanocomposite, where a second phase, graphene, is introduced in the nanostructured CoSb3 matrix via an in situ one-pot solvothermal route. In addition, CoSb3/G bulk materials were prepared by hot pressing the solvothermally synthesized CoSb3/G powder. It was found that addition of a small amount of graphene can drastically enhance the electrical conductivity due to the increase in both carrier concentration and mobility. In addition, the well dispersed graphene in the nanostructured CoSb3 matrix also contributes to the low lattice thermal conductivity. A dimensionless figure of merit ZT = 0.61 at 800 K has been obtained for the CoSb3/G nanocomposite, which is about a 130% improvement over that of graphene-free CoSb3 (∼0.26).
Co-reporter:Shuangyu Liu, Jian Xie, Haibo Li, Ye Wang, Hui Ying Yang, Tiejun Zhu, Shichao Zhang, Gaoshao Cao and Xinbing Zhao
Journal of Materials Chemistry A 2014 - vol. 2(Issue 42) pp:NaN18131-18131
Publication Date(Web):2014/09/02
DOI:10.1039/C4TA03192J
The rapid development of microelectronic devices has stimulated an increasing demand for micro-energy storage devices, typically, micro-supercapacitors (MSCs). Despite recent advances, the fabrication of MSCs using a facile, scalable and inexpensive method still remains challenging. In this work, we use a facile screen printing technique to fabricate flexible all-solid-state MSCs using N-doped reduced graphene oxide (rGO) as the electrode material. The effective area of MSCs and the thickness of the active material are only 0.396 cm2 and 10 μm, respectively. The MSCs can deliver a high specific areal capacitance of 3.4 mF cm−2, which is among the high values of graphene-based materials for all-solid-state MSCs reported so far. Easy fabrication and good performance make MSCs promising on-chip energy storage devices.
Co-reporter:Longhuan Liao, Hongtao Wang, Hui Guo, Peiyi Zhu, Jian Xie, Chuanhong Jin, Shichao Zhang, Gaoshao Cao, Tiejun Zhu and Xinbing Zhao
Journal of Materials Chemistry A 2015 - vol. 3(Issue 38) pp:NaN19375-19375
Publication Date(Web):2015/08/14
DOI:10.1039/C5TA05358G
Fe doping is widely used to improve the electrochemical performance of LiMnPO4 by “implanting” the merits of high rate capability and long cycle life of LiFePO4 into LiMnPO4. Nevertheless, great challenges still remain to obtain high-performance LiFexMn1−xPO4 at a low x value. In this work, we synthesized ultrathin LiFexMn1−xPO4 (x ≤ 0.15) nanoplates by a facile, controllable method. The plate-like LiFexMn1−xPO4 with a small lateral size (40–100 nm) and thickness (10–20 nm) exhibits high electrochemical activity, excellent rate capability and superior cycling stability after carbon coating. At a rate as high as 50C (8.5 A g−1), the LiFe0.15Mn0.85PO4/C composite can still yield a high discharge capacity of 96.2 mA h g−1 where the discharge process can be completed in only 40 s. LiFe0.15Mn0.85PO4/C can sustain a long-term cycling up to 1000 cycles at 10C with a capacity retention close to 70%. The fast and stable cycling ability of LiFexMn1−xPO4 makes it promising for applications in electric vehicles and hybrid electric vehicles.
Co-reporter:Xueke Xia, Jian Xie, Shichao Zhang, Bin Pan, Gaoshao Cao and Xinbing Zhao
Inorganic Chemistry Frontiers 2017 - vol. 4(Issue 1) pp:NaN138-138
Publication Date(Web):2016/11/23
DOI:10.1039/C6QI00286B
Owing to the increasing concerns regarding limited lithium reserves, sodium-ion batteries (SIBs) have attained worldwide attention in recent years. However, there is still a challenge to find suitable anodes for SIBs with high capacity and a long cycle life. In this work, we propose a unique feather-like array-type anode composed of thin Ni3S2 nanosheets anchored on cracked carbon submicron tubes (CSTs) on a porous Ni foam substrate. The porous structure of the Ni foam facilitates electrode wetting by the electrolyte. The voids in between the Ni3S2/CST arrays provide free space for buffering volume changes upon sodiation/desodiation. The CSTs not only act as the support for Ni3S2 growth but also uniformly disperse the Ni3S2 nanosheets, leading to high capacity and good capacity retention. The Ni-supported Ni3S2/CSTs can deliver a high initial reversible capacity of 887 mA h g−1 at 50 mA g−1. The reversible capacity can be kept at 212 mA h g−1 after 260 cycles. This work will shed light on the design of high-performance SIB anodes.
Co-reporter:Can Cao, Jian Xie, Shichao Zhang, Bin Pan, Gaoshao Cao and Xinbing Zhao
Journal of Materials Chemistry A 2017 - vol. 5(Issue 14) pp:NaN6755-6755
Publication Date(Web):2017/03/09
DOI:10.1039/C7TA00416H
Lithium–oxygen (Li–O2) cells are receiving intense interest because of their extremely high energy density. A highly efficient catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key factor influencing the performance of lithium–oxygen cells. In this work, we prepared a highly efficient CeO2-decorated δ-MnO2 (CeO2/δ-MnO2) catalyst which is composed of graphene-like δ-MnO2 with ultrafine CeO2 nanocrystals decorated on it. Li–O2 cells with the CeO2/δ-MnO2 catalyst exhibit superior electrochemical performance, including high discharge specific capacity (8260 mA h g−1 at 100 mA g−1), good rate capability (735 mA h g−1 at 1600 mA g−1), and excellent cycling stability (296 cycles at a limited capacity of 500 mA h g−1), which is much better than that with a bare δ-MnO2 catalyst. The achievement of excellent electrochemical performance is attributed to the highly efficient co-catalytic ability of δ-MnO2 and CeO2 and the desirable graphene-like architecture of the CeO2/δ-MnO2 catalyst, as well as the formation of the thin-layered discharge product Li2O2.
