Synergistic Bimetallic CoCu‐Codecorated Carbon Nanosheet Arrays as Integrated Bifunctional Cathodes for High‐Performance Rechargeable/Flexible Zinc‐Air Batteries
Jiaqi Kuang, Yirun Shen, Yang Zhang, Jun Yao, Jiajun Du, Siyuan Yang, Shengsen Zhang, Yueping Fang, Xin Cai
Abstract
Abstract The unremitting exploration of well‐architectured and high‐efficiency oxygen electrocatalysts is promising to speed up the surface‐mediated oxygen reduction/evolution reaction (ORR/OER) kinetics of rechargeable zinc–air batteries (ZABs). Herein, bimetallic CoCu‐codecorated carbon nanosheet arrays (CoCu/N‐CNS) are proposed as self‐supported bifunctional oxygen catalysts. The integrated catalysts are in situ constructed via a simple sacrificial‐templated strategy, imparting CoCu/N‐CNS with 3D interconnected conductive pathways, abundant mesopores for electrolyte penetration and ion diffusion, as well as Cu‐synergized Co – N x /O reactive sites for improved catalytic activities. By incorporating a moderate amount of Cu into CoCu/N‐CNS, the bifunctional activities can be further increased due to synergistic oxygen electrocatalysis. Consequently, the optimized CoCu/N‐CNS realizes a low overall overpotential of 0.64 V for OER and ORR and leads to high‐performance liquid ZABs with high gravimetric energy (879.7 Wh kg −1 ), high peak power density (104.3 mW cm −2 ), and remarkable cyclic stability upon 400 h/1000 cycles at 10 mA cm −2 . More impressively, all‐solid‐state flexible ZABs assembled with the CoCu/N‐CNS cathode exhibit superior rate performance and exceptional mechanical flexibility under arbitrary bending conditions. This CoCu/N‐CNS monolith holds significant potential in advancing cation‐modulated multimetallic electrocatalysts and multifunctional nanocatalysts.