Atomic Engineering of Bifunctional Core–Shell Catalysts with Dual Single‐Atom and Cobalt Nanoparticles for Boosting ORR and OER Kinetics in Zn–Air Batteries

Abstract The development of a bifunctional catalyst with superior oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) capabilities is an important key for rechargeable zinc–air batteries (RZABs). In this study, the core–shell synthesis and ammonia treatment strategy are utilized to fabricate novel bifunctional catalysts comprising Fe single atoms, Co single atoms, and Co nanoparticles (Co NP ) in a 3D hierarchical porous nitrogen‐carbon framework (NCF), addressed as A‐Co‐Fe/NCF‐Co NP . The catalyst demonstrates an outstanding ORR and OER activity with a narrow gap of 0.69 V. The ZAB with the novel catalyst and innovatively designed cathode exhibits a maximum power of 294 mW cm −2 and can be operated for 1129 h (3340 cycles) at 10 mA cm −2 . In the case of the rechargeable flexible zinc‐air battery, the ZAB is operated for 210 h (620 cycles) at 2 mA cm −2 . These results show that the ZAB with A‐Co‐Fe/NCF‐Co NP possesses outstanding stability and durability, which has high potential for ZAB applications.