A high-performance chemically self-charging aqueous zinc battery using a porous organic polymer cathode
Xiaojuan Chen, Yanwei Ma, Yiwen Lu, Huimin Zhang, Baozhu Yang, Qi Liu
Abstract
In order to cope with harsh situations without an external power supply, developing high-performance aqueous zinc batteries (AZBs) with chemically self-charging as a self-powered system is of great practical significance. Herein, we present the synthesis of a new porous organic polymer with hexaazatriphenylene hexacarboxylic acid trianhydride (HHAT) and 2,6-diaminoanthraquinone (DAAQ) units (HTAQ). Due to its π -conjugated aromatic structure with abundant redox-active centers and limited solubility in electrolytes, the constructed flexible and coin-type AZBs based on HTAQ cathodes display a superior volume energy density (8.7 mWh/cm 3 ) and a higher energy density (104 Wh/kg), respectively, and excellent cycle life, where both Zn 2+ and H + ions participate in the cathode reaction. Impressively, the electric energy exhausted flexible Zn//HTAQ AZB can be chemically self-recharged by exposing the discharged HTAQ cathode to air, ascribing to the spontaneous redox reaction between O 2 and the discharged HTAQ cathode. The exhausted flexible Zn//HTAQ AZB after air-charging for 30 h, can present a high discharge capacity of 294 mAh/g at 0.5 A/g, a higher self-charging cycle stability (15 cycles), a high-rate capability, and work well at hybrid modes (chemical or/and galvanostatic charging). Our work opens a new route to construct high-performance self-powered systems based on AZBs.