Zn-doped V2O5 film electrodes as cathode materials for high-performance thin-film zinc-ion batteries

Abstract

Zn-doped V₂O₅ film electrodes were prepared by in-situ growth on indium‑tin oxide (ITO) conductive glass by a low-temperature liquid-phase deposition method and calcined by calcination treatment, and assembled into thin-film zinc-ion batteries (ZIBs). After galvanostatic charge/discharge (GCD) tests with 90 and 200 charge/discharge cycles, the ZIBs system provided specific capacities of 95.7 mAh m⁻² and 63.9 mAh m⁻² with capacity retention rates of 97.88% and 78.72%, respectively. The electrochemical reaction process of the Zn-doped V₂O₅ film electrode was analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to understand the insertion/extraction mechanism of Zn²⁺. The doping of appropriate amount of Zn²⁺ in the preparation plays the role of “pillar”, which helps to stabilize the structure of V₂O₅ and improve the cycling stability and lifetime. Therefore, the research may provide a new idea for the assembly and preparation of thin-film ZIBs with improved performance.