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/Co9S8@N, S-PC.•Co/Co9S8@N, S-PC-N exhibits a unique porous morphology and optimized structure and composition.•Co/Co9S8@N, S-PC-N possesses outstanding exhibits the performance of double-effect oxygen catalysis.