Geometric and Electronic Engineering of Atomically Dispersed Copper-Cobalt Diatomic Sites for Synergistic Promoting Bifunctional Oxygen Electrocatalysis in Zinc-Air Batteries.
Zhijun LiSiqi JiChun WangHongxue LiuLeipeng LengLei DuJincheng GaoMan QiaoJ Hugh HortonYu WangPublished in: Advanced materials (Deerfield Beach, Fla.) (2023)
The development of rechargeable zinc-air batteries is heavily dependent on bifunctional oxygen electrocatalysts to offer exceptional oxygen reduction/evolution reaction (ORR/OER) activities. However, the design of such electrocatalysts with high activity and durability is challenging. Herein, we propose a strategy to create an electrocatalyst comprised of copper-cobalt diatomic sites on a highly porous nitrogen-doped carbon matrix (Cu-Co/NC) with abundantly accessible metal sites and optimal geometric and electronic structures. Experimental findings and theoretical calculations demonstrate that the synergistic effect of Cu-Co dual-metal sites with metal-N 4 coordination induce asymmetric charge distributions with moderate adsorption/desorption behavior with oxygen intermediates. This electrocatalyst exhibited extraordinary bifunctional oxygen electrocatalytic activities in alkaline media, with a half-wave potential of 0.92 V for ORR and a low overpotential of 335 mV at 10 mA cm -2 for OER. In addition, it demonstrated exceptional ORR activity in acidic (0.85 V) and neutral (0.74 V) media. When applied in zinc-air battery, it achieved extraordinary operational performance and outstanding durability (510 h), ranking it as one of the most efficient bifunctional electrocatalysts reported to date. This work demonstrates the importance of geometric and electronic engineering of isolated dual-metal sites for boosting bifunctional electrocatalytic activity in electrochemical energy devices. This article is protected by copyright. All rights reserved.