Electroactivation-induced hydrated zinc vanadate as cathode for high-performance aqueous zinc-ion batteries

Abstract Aqueous zinc-ion batteries have great potential applications in the field of energy storage; however, their development is limited by the low availability of high-performance cathode materials. In this study, the phase transformation of Yolk-shell V2O5 (YS-V2O5) to hydrated zinc vanadate (Zn0.34V2O5•0.37H2O; HZVO) was driven by water molecules via electrochemical activation. The resulting HZVO was used as the host material for the insertion/extraction of zinc ions. The HZVO material exhibited a specific capacity of 85.2% (113.3 mA h g−1) after 1000 cycles at a current density of 8.0 A g−1. Moreover, the diffusion coefficient of zinc ions was larger than that of conventional cathode materials, ranging from 10−9 to 10−8 cm2 s−1. We believe that our approach can contribute to the development of advanced cathode materials for application in zinc-ion batteries.