Ultrafast Self‐Charging in Acid–Base Free Aqueous Rechargeable Zinc–Quinhydrone Batteries

Abstract In the field of energy technologies, self‐charging batteries are receiving extensive attention. However, the existing technologies are highly dependent on the available sources of O 2 , have long self‐charging duration, and have complex architectures. Herein, a novel ultrafast chemical self‐charging Zn‐quinhydrone polymer gel (QPG) battery, composed of acid/base free quinhydrone as a cathode material is reported. The prepared Zn–QPG battery exhibits a specific capacity of 209.7 mAh g −1 at 10C rate and maintains 86.4% of the initial discharge capacity even after 3000 cycles with a high coulombic efficiency of 99.4%. The aqueous amphiphilic block co‐polymer‐driven selective oxidation of hydroquinone (HQ) to benzoquinone (BQ) compels the chemical self‐charging feature wherein the device attains ≈1.1 V within ten minutes of complete discharge. The chemical self‐charging generated a high specific capacity of 197.8 mAh g −1 at 10C rate with a capacity retention of 91.2% after 100 cycles. Moreover, a flexible Zn–QPG battery also demonstrates excellent rechargeability and power‐delivering ability even in a wrist‐bend geometry. This work paves the way to develop ultrafast energy storage systems, which are not dependent on an external power supply and broaden the horizon of aqueous zinc–organic batteries.