Safe and versatile single-ion conducting gel polymer electrolyte for lithium metal batteries

The increasing demand for electrified devices necessitates the exploration of alternative battery systems for highenergy applications. In this context, lithium-metal batteries (LMBs) have arisen as a promising solution. However, the development of LMBs faces important safety concerns due precisely to the utilization of lithium metal as the anode. To overcome these challenges, gel polymer electrolytes (GPEs) emerge as a promising solution, offering improved safety compared to liquid electrolytes, without compromising their excellent electrochemical properties. Herein, the development of a new GPE based on the incorporation of a single-ion conducting polymer in a poly(ethylene glycol) diacrylate matrix is reported. The polymer membranes show self-standing and flexible properties, suitable ionic conductivity of 2.5 x 10-5 S cm-1 at 40 degrees C combined with a high lithium transference number of 0.85, excellent compatibility with lithium metal anode and sufficient anodic stability. These properties enable the newly developed GPE to be used with various active materials spanning different voltage windows, showcasing its versatility and demonstrating stable cycling even under challenging cathode loadings above 1.5 mAh cm-2.