Proton Chemistry Induced Long‐Cycle Air Self‐Charging Aqueous Batteries

Air self‐charging aqueous metal‐ion batteries usually suffer from capacity loss after self‐charging cycles due to the formation of basic salts on cathodes in the near‐neutral electrolytes. Here, air self‐charging Pb/pyrene‐4,5,9,10‐tetraone (PTO) batteries based on proton chemistry are developed in acidic electrolyte. The fast kinetics of H+ uptake/removal endows the battery with enhanced electrochemical performance. Owing to the high standard electrode potential of oxygen in acid electrolyte, the discharged cathodes are spontaneously oxidized by oxygen in air along with H+ extraction and thus achieve self‐charging without external power supply. Notably, the air self‐charging mechanism involved H+‐based redox can effectively avoid the generation of basic salts on self‐charging electrodes and thus guarantee long‐term self‐charging/galvanostatic discharging cycles of Pb/PTO batteries. This work provides a promising strategy for designing long‐cycle air self‐charging systems. An air self‐charging Pb/pyrene‐4,5,9,10‐tetraone (PTO) battery was developed in acidic electrolyte. The Pb/PTO batteries display excellent cycle stability during repeated self‐charging/galvanostatic discharging process because the self‐charging behavior in acidic medium can effectively avoid the formation of basic salts on self‐charging electrode.