An Ultrafast Air Self‐Charging Zinc Battery

Abstract Air self‐charging power systems possess the capability of energy harvesting, conversion, and storage simultaneously. However, in general, their self‐charging rate is slow and the batteries cannot be oxidized to the fully charged state due to the weak oxidizability of O₂. Herein, an ultrafast air self‐charging aqueous zinc battery is designed by constructing a polyaniline@Pt/C (PANI@Pt/C) composite cathode. The introduction of Pt/C catalyst endows the redox reaction between PANI and O₂ with fast reaction kinetics and extended redox potential difference. Therefore, the self‐charging rate of the Zn/PANI@Pt/C batteries is effectively accelerated and they can be self‐charged to fully charged state. Furthermore, the PANI can be recharged by O₂ simultaneously during discharging process to compensate the consumed electrical energy, achieving prolonged energy supply. In addition, the PANI@Pt/C cathodes can be directly used as the cathodes of flexible self‐charging zinc batteries due to their excellent mechanical properties. As a proof of concept, flexible soft‐packaged Zn/PANI@Pt/C batteries are fabricated and displayed stable electrochemical performance and self‐rechargeability even at different bending states. A route is provided here to design ultrafast chemical self‐charging energy storage devices and the horizons of flexible energy storage devices are broadened.