V2O5 nanocrystals: Chemical solution synthesis, hydrogen thermal treatment and enhanced rate capability as cathode materials for lithium-ion batteries

Vanadium pentoxide (V2O5) is regarded as a promising cathode material for high-performance lithium-ion batteries (LIBs). In this study, V2O5 nanocrystals with an elongated plate-like morphology are prepared via a chemical solution approach that involves the hydrolyzation of vanadyl sulfate in alkaline solution. Oxygen vacancies are intentionally created by thermal treating the V2O5 samples under hydrogen-containing gases at different temperatures. Although the annealing process does not change the shape, morphology and crystalline structure of V2O5 nanocrystals, it does bring about a small amount of oxygen vacancies, as evidently from the results of XRD patterns and Raman spectra. The presence of oxygen vacancies has positive effects on the electrochemical properties. A higher initial discharge capacity, and excellent rate capability and cycling stability are observed on the oxygen vacancy-containing V2O5 samples. Especially, the sample annealed at 350 degrees C is found to have an initial capacity of 284 mAh g(-1) and the capacity still maintains at about 153 mAh g(-1) even at 10 C. The combination of nanoscale dimension and oxygen vacancies in V2O5 nanocrystals presents a simple way to improve their rate capability and cycling stability for potential highperformance LIB applications. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The presence of oxygen vacancies has positive effects on the electrochemical properties of V2O5 nanocrystals, leading to higher initial discharge capacity, excellent rate capability, and cycling stability. A simple way to improve the rate capability and cycling stability of V2O5 nanocrystals for high-performance LIB applications is through the combination of nanoscale dimensions and oxygen vacancies.