V4+-V2O5 nano-plate material for effectively improving lithium storage performance of lithium-ion batteries

摘要

With the rapid development of high-power appliances, the demand for higher power density lithium-ion batteries has soared. Benefitting from its large theoretical capacity and high working voltage, vanadium oxide is considered to be a promising candidate for the next generation of cathode materials for lithium-ion batteries. Among them, orthorhombic V2O5, with characteristics of easy synthesis and high safety, is prominent and gaining much attention. However, the cycling performance of V2O5, affected by low electrical conductivity and easy solubility in the electrolyte, is not satisfactory and this has become a stumbling block on the way to its development. This work reports the V4+ doped V2O5 nanoplate material prepared by the hydrothermal method that has excellent electrochemical properties giving the credit to the increased conductivity and expanded interlayer spacing caused by V4+. After doping with V4+, the specific capacity of the V-V2O5 electrode is as high as 301.1 mAh g(-1) at a current density of 100 mA g(-1), and even more surprisingly, the capacity of the V-V2O5 electrode is still as high as 158.9 mAh g(-1) at an ultra-high current density of 4 A g(-1), showing excellent rate performance. This study provides sufficient theoretical support and reference for further exploration of self-doped materials in lithium-ion battery field.

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