A Function‐Separated Design of Electrode for Realizing High‐Performance Hybrid Zinc Battery

Abstract

AbstractA rechargeable hybrid zinc battery is developed for reaching high power density and high energy density simultaneously by introducing an alkaline Zn–transition metal compound (Zn–MX) battery function into a Zn–air battery. However, the conventional single‐layer electrode design cannot satisfy the requirements of both a hydrophilic interface for facilitating ionic transfer to maximize the Zn–MX battery function and a hydrophobic interface for promoting gas diffusion to maximize the Zn–air battery function. Here, a function‐separated design is proposed, which allocates the two battery functions to the two faces of the cathode. The electrode is composed of a hydrophobic MnS layer decorated with Ni–Co–S nanoclusters that allows for smooth gas diffusion and efficient oxygen electrocatalysis and a hydrophilic NixCo1−xS2 layer that favors fast ionic transfer and superior performance for energy storage. The battery with the function‐separated electrode shows a high short‐term discharge voltage of ≈1.7 V, an excellent high‐rate galvanostatic discharge–charge with a power density up to 153 mW cm−2 at 100 mA cm−2, a good round‐trip efficiency of 75% at 5 mA cm−2, and a robust cycling stability for 330 h with an excellent voltage gap of ≈0.7 V at 5 mA cm−2.