The introduction of gallium ions into V2O5 interlayers for highly reversible Zn ion batteries

Abstract

It is very important to construct energy storage systems with high safety and excellent electrochemical performance. In particular, aqueous Zn ion batteries (AZIBs) possess the characteristics of low-cost and environmental benignity. However, there are few cathode materials that match well with the zinc anode. Herein, Ga³⁺ pre-intercalation into V₂O₅ layers promotes the insertion/extraction kinetics of zinc ions. The assembled Zn/V₂O₅–0.1Ga battery with 3 M Zn(CF₃SO₃)₂ electrolyte shows a specific capacity of 512.07 mA h g⁻¹ at a current density of 0.1 A g⁻¹. It delivers an energy density of 281.64 W h kg⁻¹ at a power density of 55 W kg⁻¹. It can also provide a reversible capacity of 110 mA h g⁻¹ at 10 A g⁻¹ with a retention rate of 91.43% after 5000 cycles, revealing its potential applications in future energy storage devices.