Application of Co/Co9S8@N, S doped porous carbon composites prepared by ball milling for zinc-air battery

• Metal sulfides were prepared by a unique strategy to achieve sulfidation and double doping with ammonium bisulfate. • The amount of ammonium bisulfate has a great effect on the synthesis of Co/Co 9 S 8 @N, S-PC. • Co/Co 9 S 8 @N, S-PC-N exhibits a unique porous morphology and optimized structure and composition. • Co/Co 9 S 8 @N, S-PC-N possesses outstanding exhibits the performance of double-effect oxygen catalysis. With the advantage of high electrocatalytic activity, cobalt sulfides has become an efficient electrocatalyst for oxygen evolution and oxygen reduction reaction (OER/ORR). Selecting an appropriate strategy to construct a optimal structure for cobalt sulfides to explore the potential of their application in zinc-air battery is one of the meaningful topics. Here we propose a facile strategy to synthesize Co/Co 9 S 8 @N, S doped porous carbon composite material with mesoporous structure by ball milling. The Co/Co 9 S 8 @N, S doped porous carbon composite material exhibits excellent dual function catalytic activity for OER and ORR. Also, the material exhibits excellent power density and cycle stability when applied to the electrode catalytic material of normal zinc-air battery. Among them, the optimal sample present better power density than Pt-Ru-C mixed catalyst used in the normal zinc-air battery, and the limit value is 202.5 mW cm -2 . Connecting two solid-state zinc-air batteries in series can meet the normal operation of 53 LED light-emitting diodes. This work can provide a powerful reference for the further development of cobalt sulfides in oxygen electrocatalysis and zinc-air battery.