Chemically embedding Co nanospheres in N-doped carbon nanosheets for enhanced zinc-air batteries

The next-generation oxygen electrochemical catalysts based on non-precious metals have been extensively studied for zinc-air batteries (ZABs). Among them, Co–N–C catalysts have attracted considerable attention due to their excellent oxygen catalytic performance. However, the synthesis of Co nanoparticles with uniform structure and distribution on conductive and stable substrates remains challenging. Herein, we have prepared cobalt nanoparticles chemically embedded in N-doped carbon nanosheets (Co@NCS) by a simple organic-inorganic hybrid molten salts method. Due to the multifunctional environment provided by the mixed salts, the Co@NCS can exhibit efficient oxygen reduction and evolution reaction (ORR/OER) performance, enabling them to be suitable in ZABs. The resulting ZABs has a considerable open-circuit voltage of 1.40 V, a good peak power density of 130.4 mW cm⁻² and long cycle stability for 100 h at 10 mA cm⁻².