Designing Gel Polymer Electrolyte with Synergetic Properties for Rechargeable Magnesium Batteries

Magnesium (Mg) batteries represent a promising candidate for energy-dense, sustainable and safe energy storage. However, the realization of practical Mg batteries remains challenging and advanced material design strategies are imperatively necessary. Herein, a novel magnesium tetrakis(hexafluoroisopropyloxy)borate-based non-corrosive gel polymer electrolyte has been synthesized by an in-situ polymerization. This gel polymer electrolyte exhibits unprecedented electrolytic properties in terms of high ionic conductivity (10 −3 S cm −1 ), reversible Mg plating/stripping capability (Coulombic efficiency ∼99%, 1000 cycles) and low voltage polarization. Simultaneously, the polymeric matrix can prevent dissolution and diffusion of soluble electrode materials. For the first time, the employment of a gel polymer electrolyte to suppress the polysulfide shuttle in Mg−S batteries has been demonstrated. Moreover, it can be extended to other polymer backbones and incorporated with other cathodes for improving battery performance.