High-performance solid-state zinc-ion batteries enabled by flexible and highly Zn2+ conductive solid-polymer electrolyte

The utilization of solid-polymer electrolytes (SPEs) is of great interest to construct high-performance energy storage systems, owing to the high flexibility/elasticity, high thermal properties, reduced dendrite formation, suppression of cathode dissolution, and overcoming of leakage and safety issues associated with liquid electrolytes. Herein, we propose a flexible and highly Zn2+ conductive solid-polymer electrolyte (SPE) for solid-state zinc-ion batteries. The proposed PVA-inter-PEG(30%)/IL70% SPE exhibits high Zn2+ ionic conductivity (2.264 mS cm(-1)), low glass transition temperature (T-g = -10.2 degrees C), good thermal stability (>200 degrees C), and higher oxidation stability against zinc (similar to 2.8 V). Moreover, PVA-inter-PEG(30%)/IL70% SPE provides a stable interfacial contact to the zinc anode and enables dendrite-free zinc stripping/platting over 3000 h of cycling at 0.2 mA cm(-2). The solid-state Zn//V10O24 center dot nH(2)O cell fabricated with PVA-inter-PEG(30%)/IL70% SPE delivered a discharge capacity as high as 325 mA h g(-1) at 0.1 A g(-1) and demonstrates good rate performance (similar to 325/110 mA h g(-1) at 0.1/10 A g(-1), respectively) with reasonable cycling stability. Besides, the PVA-inter-PEG(30%)/IL70% SPE applied in the fabrication of a flexible pouch-cell prototype demonstrates safety performance and can serve as promising and reliable energy storage devices for flexible and wearable applications.