Enhancing Rechargeable Zinc-Air Batteries with Atomically Dispersed Zinc Iron Cobalt Planar Sites on Porous Nitrogen-Doped Carbon.

Abstract

Rechargeable zinc-air batteries (ZABs) face significant challenges in achieving both high power density and long-term stability, primarily due to limitations in catalytic materials for oxygen electrodes. Here, we present a trimetal planar heterogeneous metal catalyst featuring atomically dispersed ZnN4, FeN4, and CoN4 sites supported on a porous nitrogen-doped carbon substrate (ZnFeCo-NC) through a templating approach. By fine-tuning the content of each metal, the optimized ZnFeCo-NC-based ZAB achieves a high peak power density of 244 mW cm-2 and maintains durable performance for 500 h at 10 mA cm-2. Ab initio molecular dynamics simulations reveal that the ZnFeCo-NC catalyst configuration remains stable at 300 K during the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) process. Further theoretical calculations demonstrate that the introduction of adsorbed OH groups effectively tunes the electronic structure redistribution of metal active sites, particularly improving the catalytic performance at the Fe site for ORR and the Co site for the OER. These findings provide insights into the rational design of high-performance electrocatalysts in energy storage technologies.