Highly‐Exposed Co‐CoO Derived from Nanosized ZIF‐67 on N‐Doped Porous Carbon Foam as Efficient Electrocatalyst for Zinc‐Air Battery

Abstract Non‐precious‐metal based electrocatalysts with highly‐exposed and well‐dispersed active sites are crucially needed to achieve superior electrocatalytic performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) toward zinc‐air battery (ZAB). Herein, Co‐CoO heterostructures derived from nanosized ZIF‐67 are densely‐exposed and strongly‐immobilized onto N‐doped porous carbon foam (NPCF) through a self‐sacrificial pyrolysis strategy. Benefited from the high exposure of Co‐CoO heterostructures and the favorable mass and electron transfer ability of NPCF, the Co‐CoO/NPCF electrocatalyst exhibits remarkable performance for both ORR ( E 1/2 = 0.843 V vs RHE) and OER ( E j = 10 mA cm‐2 = 1.586 V vs RHE). Further application of Co‐CoO/NPCF as the air‐cathode in rechargeable ZAB achieves superior performance for liquid‐state ZAB (214.1 mW cm −2 and 600 cycles) and flexible all‐solid‐state ZAB (93.1 mW cm −2 and 140 cycles). Results from DFT calculations demonstrate that the electronic metal‐support interactions between Co‐CoO and NPCF via abundant C‐N x sites is favorable for electronic structure modulation, accounting for the remarkable performance.