Dual‐Sites Coordination Engineering of Single Atom Catalysts for Full‐Temperature Adaptive Flexible Ultralong‐Life Solid‐State Zn−Air Batteries

Abstract High‐performance rechargeable Zn‐air batteries with long‐life stability are desirable for power applications in electric vehicles. The key component of the Zn‐air batteries is the bifunctional oxygen electrocatalyst, however, designing a bifunctional oxygen electrocatalyst with high intrinsic reversibility and durability is a challenge. Through density functional theory calculations, it is found that the catalytic activity originated from the electronic and geometric coordination structures synergistic effect of the Fe and Co dual‐sites with metal‐N 4 coordination environment, assisting the stronger hybridization of electronic orbitals between Co ( dxz, dz 2 ) and OO* ( px, pz ), thus making the stronger O 2 active ability of Co active site. These findings enable to development of a fancy dual single‐atom catalyst comprising adjacent FeN 4 and CoN 4 sites on N‐doped carbon matrix (FeCo‐NC). FeCo‐NC exhibits extraordinary bifunctional activities for oxygen reduction and evolution reaction (ORR/OER), which displays high half‐wave potential (0.893 V) for the ORR, and low overpotential (343 mV) at 10 mA cm −2 for the OER. The assembled FeCo‐NC air‐electrode works well in the flexible solid‐state Zn‐air battery with a high specific capacity of 747.0 mAh g −1 , a long‐time stability of more than 400 h (30 °C), and also a superior performance at extreme temperatures (−30 °C–60 °C).