Doping engineering: modulating the intrinsic activity of bifunctional carbon-based oxygen electrocatalysts for high-performance zinc-air batteries

Zinc-air batteries (ZABs) have been considered a promising alternative for next-generation sustainable electrical energy storage devices, owing to their low cost, safety, eco-friendliness, and high theoretical specific energy density, whereas the sluggish reaction kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) involved in the charge and discharge process of ZABs hold back the large polarization effect of ZABs. In this regard, developing electrocatalysts with considerable oxygen reaction activity (ORR/OER) is urgently needed. By virtue of the high specific surface area and enhanced electrical conductivity, carbon-based candidates have garnered considerable research attention. In this regard, the development of effective strategies to enhance the intrinsic site activity is the mainstream direction and has made great progress. Recently, doping engineering has been demonstrated as an effective strategy to promote the catalytic performance. In this review, we focus on the recent progress in developing carbon-based oxygen electrocatalysts for ZABs. And the relationship between doping engineering and the intrinsic activity of oxygen electrocatalysis is particularly outlined. This review will provide guidance for designing high-efficiency oxygen electrocatalysts, thereby further improving the energy conversion efficiency of ZABs and realizing industrialization.