Eco-Friendly Lignocellulosic Gel Polymer Electrolyte for Aqueous Zinc Energy Storage Devices

Uncontrolled dendrite growth and worse side reactions shorten the life span of aqueous zinc energy storage devices and limit their practical application. Herein, we report for the first time a high-performance lignocellulosic gel polymer aqueous electrolyte (LC-GPAE) with abundant polar functional groups. The strong interaction between Zn2+ and polar functional groups inside LC-GPAE can weaken the solvation of Zn2+ with water, thus reducing the desolvation activation energy of [Zn(H2O)6]2+ and improving the kinetics of Zn2+ in the stripping/plating process. It is mainly reflected in the high ion conductivity (6.3 mS cm–1 at 30 °C), high Zn2+ transference number (tZn2+ = 0.44), and lower nucleation overpotential (58 mV). Under the action of LC-GPAE, the growth direction of Zn dendrites tends to be gentle and smooth, avoiding the penetration effect. Impressively, a Zn//Zn symmetric battery with LC-GPAE maintains stable operation over 2000 h at 1 mA cm–2 with a capacity of 1 mAh cm–2, and a Zn//AC hybrid supercapacitor with LC-GPAE continuously runs over 12,500 cycles at 1 A g–1 (retention rate 84.4%).