Synergistic Bimetallic CoCu‐Codecorated Carbon Nanosheet Arrays as Integrated Bifunctional Cathodes for High‐Performance Rechargeable/Flexible Zinc‐Air Batteries

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.