Influence of TiO2 surface coating on the electrochemical properties of V2O5 micro-particles as a cathode material for lithium ion batteries

摘要

V2O5 micro-particles were obtained by the mechanical milling process combined with a simple sintering treatment using commercial V2O5 powder as a raw material. We successfully adopted the hydroxylation of tetrabutyl titanate (C16H36O4Ti) in air and a post-sintering procedure to synthesize the TiO2-coated V2O5 micro-particles. Afterwards, systematic electrochemical characterization was performed to evaluate the electrochemical performance of V2O5 micro-particles as a cathode material for lithium ion batteries (LIBs) with and without the TiO2 coating. As for the V2O5 micro-particles, the maximum discharge specific capacity reaches 247.8 mA h g(-1), which gradually decreases to 212.6 mA h g(-1) after 50 cycles at a current density of 100 mA g(-1) between 2 and 4 V (vs. Li/Li+). Under the same conditions, TiO2 coated V2O5 micro-particles deliver the highest capacity of 246.6 mA h g(-1) and keeps at 229.1 mA h g(-1) for the 50th cycle. The results indicated that the TiO2 coating could effectively suppress the electrochemical property degradation of V2O5 crystalline micro-particles, improving its cycling stability during long-term charge-discharge measurements through the protective role of the TiO2 layer.