The cave-embedded porous Mn2O3 hollow microsphere is synthesized from aqueous manganese chloride by a facile one-step spray pyrolysis. When evaluated as anode materials for LIBs, the as-obtained Mn2O3 microsphere easily allows the electrolyte to penetrate into the hollow interior through the cave, providing more active sites and a shortened Li+ diffusion pathway. As a result, the enhanced charge transfer and lithium ion diffusion kinetics is achieved. Furthermore, the special structure is able to mitigate the stress led by enormous volume variation and maintain the structural integrity during conversion reaction process. Benefiting from the special structural features, the Mn2O3 microspheres with such smart architecture delivers a reversible capacity of ∼1000 mAh g−1 at 300 mA g−1 after 100th cycle, and maintains a high reversible capacity of 639 mAh g−1 at 1600 mA g−1, showing better electrochemical performance than the conventional Mn2O3 microspheres.

Nanoparticles-assembled Co3O4 microspheres with different primary particle size are synthesized via a facile one-step ultrasonic spray pyrolysis process, using CoCl2·6H2O as precursor. The as-synthesized Co3O4 powders are directly used as anode material for Li-ion batteries without further calcinations. The primary particle size is tuned by controlling the spray pyrolysis temperature and its effects on the electrochemical performance of the prepared samples are systemically investigated. The results reveal that primary particles size exerts significant effect on the initial coulombic efficiency, specific capacity and rate performance. In addition, we find that the temperature of powder collector strongly influences the chlorine content in the products, which is resulted from the chloridization of Co3O4 by gaseous HCl from the off-gas. A simple and effective strategy is proposed to prevent the chloridization reaction. The sample with the smallest primary particle size and low Cl content shows the highest initial coulombic efficiency of 73% and a high reversible capacity of 1340 mA h g−1 after 50 cycles at a current density of 200 mA g−1.

Hierarchical mesoporous hybrid NiO–MnCo2O4 microspheres are synthesized by a robust one-pot spray pyrolysis process. The mesoporous hybrid NiO–MnCo2O4 microspheres are comprised of homogeneously dispersed nanoscaled NiO and MnCo2O4 subunits. Specific surface area of the mesoporous hybrid NiO–MnCo2O4 microspheres is determined to be 10.2 m2 g−1 with dominant pore size of 25.8 nm. The as-obtained material is evaluated as anode material for LIBs. The as-prepared hybrid NiO–MnCo2O4 sample demonstrate better electrochemical performances, including higher reversible capacity and superior rate capability, compared with the single-phase NiO and MnCo2O4 samples. These superior electrochemical performances should be mainly attributed to its porous microstructure characteristics and the synergistic effects between the well-dispersed NiO and MnCo2O4 nanophases. The strategy is simple and flexible, so it could be readily generalized to construct other hybrid metal oxides materials.

•1-Propylphosphonic acid cyclic anhydride (PACA) is investigated as an additive.•Self-discharge of LiNi0.5Mn1.5O4 is effectively suppressed by adding PACA into electrolyte.•Enhanced cycling performance of LiNi0.5Mn1.5O4 at elevated temperatures is achieved.•Reduced transition metal dissolution of LiNi0.5Mn1.5O4 by using PACA.Self-discharge and transition metal dissolution weaknesses bother the application of LiNi0.5Mn1.5O4 cathode material due to the severe oxidation of electrolyte at the high voltage state. A novel additive, 1-propylphosphonic acid cyclic anhydride (PACA), is desirable to prevent this oxidation. CV and charge–discharge results reveal that adding 0.5% PACA can relieve the oxidation of electrolyte. Consequently, the self-discharge and transition metal dissolution are both suppressed effectively, which is validated by self-discharge tests, XPS, and EDX analyses. Moreover, using PACA as an additive enhances the capacity retention capability of LiNi0.5Mn1.5O4 at elevated temperatures significantly.

The compatibility of graphite with 1,3-(1,1,2,2-tetrafluoroethoxy)propane (HFE) and fluoroethylene carbonate (FEC) as cosolvents is investigated with Li/graphite cells. Having lower surface tension, HFE can act as a “surfactant” to reduce the surface tension of the electrolyte, while FEC increases it. Charge–discharge tests validate that the Li/graphite cells show a superior cycling performance and rate ability in 1 M (M = mol L–1) LiPF6-ethylene carbonate (EC)/ethyl methyl carbonate (EMC)/HFE (mixing ratio: 1/1/1 in weight). Cyclic voltammetry, electrochemical impedance spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy results reveal the mechanism that HFE is reduced with EC together in an EC-based electrolyte, forming a compact surface film at the graphite surface with lower interface resistance compared with FEC. In addition, we proposed that HFE will produce fluoroalkyl lithium compounds (LiOCF2CF2CF2CF2OLi) through radical termination reaction in the reduction process.