Study on Solution Combustion Synthesis and Electrochemical Performance of V2O5-Cu as Cathode Materials for Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) are considered to be one of the most promising alternative energy sources due to their safety. Vanadium-based compounds, especially V2O5 cathode materials, have been widely studied due to the advantages of suitable working voltage windows and highly reversible redox reactions. However, the poor conductivity of V2O5 and its structural instability limit its application in AZIBs. In this paper, copper ions doped V2O5 was synthesized by a simple one-step solution combustion synthesis method to improve its structural stability and electrochemical performance. The modified material expanded the interlayer spacing and increased the ionic diffusion rate, and increased the concentration of low valence vanadium and oxygen vacancy, thereby increasing the electron mobility and promoting the electrochemical reaction, resulting in an enhanced discharge specific capacity of the material. Zinc-ion batteries assembled with V2O5-Cu as the cathode material can provide a high discharge specific capacity of 300 mAh g− 1 at 4 A g− 1, and have good cycling stability, with a capacity retention of 95% over 500 cycles.