Metal-organic framework assisted design of ZnVOx cathode for aqueous zinc batteries at extreme work condition

Abstract

Vanadium oxides with high Zn2+ storage capacity are desirable cathode materials for aqueous zinc-based batteries. However, their further application is hindered due to the slow electrochemical kinetics and low electronic conductivity. Herein, we design ZnVOx electrode materials with porous one-dimensional channels using ZIF-8 template as precursor. The unique structures provide sufficient reactive sites and spacious ion diffusion channels. The assembled Zn//2Zn-V2O5 batteries deliver a specific capacity of 526.6 mAh g-1 at 0.2 A g-1. They can charge/discharge stably for 7000 times and maintain a retention rate of 84 % at 10 A g-1. Moreover, they still work well within a wide temperature range from 30 to -40 oC. The flexible batteries also show excellent mechanical stability and durability.