Rechargeable aqueous Zn-air batteries: coupled interfacial chemistry from oxygen electrocatalysis to Zn-anode regulation

Rechargeable aqueous Zn-air batteries (ZABs) combine a high theoretical energy density with low material cost and intrinsic safety, yet their practical performance remains constrained by mutually coupled reactions at the air cathode, electrolyte, and Zn anode. At the cathode, sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), catalyst degradation, carbon corrosion, and unstable gas-liquid-solid interfaces increase polarization. At the anode, ZnO passivation, corrosion, hydrogen evolution, dendritic deposition, and shape change undermine Zn reversibility and utilization. The electrolyte links these processes by governing OH^- and zincate transport, water activity, solvation, interfacial adsorption, and discharge-product evolution. Rather than treating air-cathode catalysis, Zn-anode regulation, and electrolyte engineering as isolated topics, this review adopts coupled interfacial chemistry as a unifying framework to connect oxygen electrocatalysis, Zn dissolution/deposition, electrolyte-mediated transport, and discharge-product evolution. We critically assess bifunctional oxygen electrocatalysts, Zn-anode structural and interfacial regulation, electrolyte additives, alternative Zn-storage pathways, and machine-learning-assisted optimization. Particular emphasis is placed on regulating not only interfacial reaction kinetics but also the form, location, and conversion pathway of Zn-containing species. We further highlight a transition from isolated component optimization toward mechanism-informed, multi-objective full-cell design under application-relevant conditions.