Highly Stable Zinc Anodes Achieved by Regulating Zinc Ions Deposition Through Polyimide Glue Functionalized Composite Separators

Aqueous zinc ion batteries have attracted much attention due to their abundant resources, high safety and low cost. However, the problems of uncontrolled dendrites growth, corrosion, and hydrogen evolution of zinc anodes seriously restrict the cycling life of batteries, limiting the large-scale applications. Herein, a simple drop-coating method is applied to prepare polyimide (PI) glue functionalized glass fiber separators (PI-GF). The carbonyl group in imide (–CO–N–CO–) group of polyimide has a strong adsorption effect on Zn, which helps accelerate the conduction of Zn2+, reduce the nucleation overpotential, and realize fast reaction kinetics. The composite separators reduce the concentration polarization, promote the uniform deposition of Zn2+ to inhibit the growth of dendrites, and thus significantly improving the stability of zinc anodes. Most anticipatedly, the Zn//Zn symmetric battery using the PI-GF separator exhibits a highly reversible plating/stripping behavior and can be stably cycled for 1280 h at 1 mA cm−2 and 1 mAh cm−2. The Zn//V2O5 full battery also delivers an excellent cycling stability with a high capacity of up to 235.5 mAh g−1 after 1000 cycles at a current density of 1 A g−1. This work provides a simple and effective method to improve the electrochemical performance of zinc anodes.