High-voltage operation of a V2O5 cathode in a concentrated gel polymer electrolyte for high-energy aqueous zinc batteries

Gel-type polymer electrolytes are very promising to replace liquid electrolytes, addressing the leakage concerns in batteries. In this work, we report a concentrated gel polymer electrolyte for aqueous zinc-metal batteries, which manifests superior Zn stripping/plating reversibility and electrolyte stability, combined with a promising electrochemical stability window and robust water-retention ability. Quasi-solid-state Zn/V2O5 batteries employing such an electrolyte reach a specific energy of 326 W h kg(-1) at 20 mA g(-1) based on the cathode mass and a capacity retention of 93% over 600 cycles at 500 mA g(-1). Moreover, the cell performs well in the 0-40 degrees C temperature range without significant capacity loss. These results represent important steps toward the development of high-energy aqueous zinc batteries.