CoNiFe‐layered double hydroxide decorated Co‐N‐C network as a robust bi‐functional oxygen electrocatalyst for zinc‐air batteries

Abstract

AbstractRechargeable zinc‐air batteries (ZABs) are cost‐effective energy storage devices and display high‐energy density. To realize high round‐trip energy efficiency, it is critical to develop durable bi‐functional air electrodes, presenting high catalytic activity towards oxygen evolution/reduction reactions together. Herein, we report a nanocomposite based on ternary CoNiFe‐layered double hydroxides (LDH) and cobalt coordinated and N‐doped porous carbon (Co‐N‐C) network, obtained by the in‐situ growth of LDH over the surface of ZIF‐67‐derived 3D porous network. Co‐N‐C network contributes to the oxygen reduction reaction activity, while CoNiFe‐LDH imparts to the oxygen evolution reaction activity. The rich active sites and enhanced electronic and mass transport properties stemmed from their unique architecture, culminated into outstanding bi‐functional catalytic activity towards oxygen evolution/reduction in alkaline media. In ZABs, it displays a high peak power density of 228 mW cm−2 and a low voltage gap of 0.77 V over an ultra‐long lifespan of 950 h.image