ORR/OER activity and zinc-air battery performance of various kinds of graphene-based air catalysts

The strategies used to achieve much high capacity, cycling performance, and energy density for zinc-air batteries with graphene-based air catalysts have been reviewed. This review concluded that zinc-air batteries with graphene-based air catalysts afford conceivable development for practical application in terms of high capacity, cycling performance, and energy density. [Display omitted] •Potential graphene-based air catalysts for zinc-air batteries are reviewed.•Zinc-air batteries with graphene-based air catalysts afford high capacity.•Zinc-air batteries with graphene-based air catalysts afford high cycling performance.•Zinc-air batteries with graphene-based air catalysts afford high energy density. The development of cheap and efficient oxygen reduction and evolution reaction catalysts are important, which not only push the electrochemical energy systems including water electrolyzers, metal-air batteries, and fuel cells nearer to their theoretical limits but also become the substitute for the expensive noble metal catalysts (Pt/C, IrO2 or RuO2 and Pt-Ru/C). In this review, the recently reported potential graphene-based air catalysts such as graphene with non-metals, non-noble metals, metal oxides, nitrides, sulfides, carbides, and other carbon composites are identified in-light-of-their high oxygen reduction reaction/oxygen evolution reaction activity and zinc-air battery performance for the development of high energy density metal-air batteries. Further, the recent progress on the zinc-air batteries including the strategies used to improve the high cycling-performance (stable even up-to 394 cycles), capacity (even up-to 873 mAh g−1), power density (even up-to 350 mW cm−2), and energy density (even up-to 904 W h kg−1) are reviewed. The scientific and engineering knowledge acquired on zinc-air batteries provide conceivable development for practical application in near future.