A high-performance air-rechargeable aqueous Zn/organic battery with Zn2+ and H+ storage

Abstract

Air-rechargeable aqueous zinc-ion batteries (AZIBs) as a self-powered system can solve a pressing need when there is no external power supply. To meet the demands of such harsh environments, it is necessary to develop high-performance air-rechargeable AZIBs. Herein, we constructed coin-type and flexible AZIBs using tris(1H-1,2,4-triazolyl)hexaazatriphenylenehexacarboxy triimide (TTA-HATTI) as the cathode material, where the cathode reaction involves uptake/remove of Zn2+ and H+ ions. The coin-type and flexible Zn//TTA-HATTI AZIBs exhibit a higher energy density (102.3 Wh kg−1) and a high volume energy density (8.5 mWh cm−3), respectively, and high-rate performance. Interestingly, the discharged TTA-HATTI cathode of flexible Zn//TTA-HATTI battery can be oxidized by O2 from air, due to the potential difference between them, resulting in the discharged flexible Zn//TTA-HATTI battery can be air-recharged without an external power supply. After being left in the air for 23 h, such flexible Zn//TTA-HATTI battery can exhibit a high discharge capacity (420 mA h g−1 at 0.5 A/g), a high rate-performance (178 mA h g−1 at 20 A/g), a better air-charging cycle stability (10 cycles) and operate well at chemical or/and galvanostatic charging mixed modes, showing superior reusability. This work provides guidance for developing high-performance air-rechargeable flexible AZIBs.