N-Doped C Concatenates FeCo Alloys and Co Nanoparticles as a Dual-Functional Oxygen Catalyst for Long-Lasting Zinc–Air Batteries

Abstract

Cathode electrocatalysts with rich active sites are indispensable for achieving the superior performance of zinc−air batteries (ZABs). However, the integration of both oxygen reduction reaction and oxygen evolution reaction (ORR and OER) catalytic active sites poses challenges due to their opposite catalytic mechanisms. Besides, a mass of highly oxidizing intermediates generated by the OER site would attack the adjacent ORR active sites. Herein, a bottom-up strategy is developed to catenate the Co and FeCo beads onto the needle carbon connexons, wherein the FeCo alloys undergo self-reconstruction into FeOOH and Co(OH) 2 to facilitate the OER, while the separated Co nanoparticles play a crucial role in promoting the ORR. The FeCo AL &Co NP /NC Janus material exhibits significant potential in stabilizing its bifunctional oxygen electrocatalytic properties, bestowing rechargeable ZABs with long cycling stability (752 h) as the air−cathode catalyst. This study paves a pathway for the precise manipulation of the distribution of distinct active sites and selective control over oxygen electrocatalysts.