Synergy of Pyridinic‐N and Co Single Atom Sites for Enhanced Oxygen Redox Reactions in High‐Performance Zinc‐Air Batteries

Abstract Cobalt single‐atom catalysts (SACs) have the potential to act as bi‐functional electrocatalysts for the oxygen‐redox reactions in metal‐air batteries. However, achieving both high performance and stability in these SACs has been challenging. Here, a novel and facile synthesis method is used to create cobalt‐doped‐nitrogen‐carbon structures (Co‐N‐C) containing cobalt‐SACs by carbonizing a modified ZIF‐11. HAADF‐STEM images and EXAFS spectra confirmed that the structure with the lowest cobalt concentration contains single cobalt atoms coordinated with four nitrogen atoms (Co‐N₄). Electrochemical tests showed that this electrocatalyst performed exceptionally well in both oxygen reduction reaction (ORR) (E1/2 ≈ 0.859 V) and oxygen evolution reaction (OER) (Ej = 10: 1.544 V), with excellent stability. When used as a bi‐functional electrocatalyst in the air cathode of a rechargeable zinc‐air battery (ZAB), a peak power density of 178.6.1 mW cm −2 , a specific capacity of 799 mA h g Zn −1 and a cycle‐life of 1580 is achieved. Density functional theory (DFT) calculations revealed that the concentration and the position of the pyridinic nitrogen with Co play a critical role in determining the overpotential of this electrocatalyst for oxygen‐redox reactions. The unprecedented performance of this electrocatalyst can bring paradigm changes in the practical realization and application of metal‐air batteries.