High-Performance and Chemically Self-Charging Flexible Aqueous Zinc-Ion Batteries Based on Organic Cathodes with Zn2+ and H+ Storage

Chemically self-charging aqueous zinc-ion batteries (AZIBs) via air oxidation will provide new opportunities for future wearable electronic devices. Herein, we display two high-performance flexible AZIBs based on a trifluorohexaazatrinaphthylene (TFHATN)/trichlorohexaazatrinaphthylene (TCLHATN) cathode, which can be recharged via air without using an external power supply. The flexible Zn//TFHATN/Zn//TCLHATN battery presents good mechanical flexibility and high volumetric energy density of 9.2/10.7 mWh cm–3. The air-recharging capability originates from a spontaneous redox reaction between the discharged TFHATN/TCLHATN cathode and O2 from air. After exposure to air for 15 h, the discharged Zn//TFHATN/Zn//TCLHATN battery can be recharged to around 1.2 V, exhibits high discharge capacity, high rate performance, and higher self-charging cycle stability (8 cycles), and works well in chemical and/or galvanostatic charging mixed modes, displaying good reusability. This work provides a strategy for developing high-performance, flexible air-rechargeable AZIBs.