Ionic Liquid‐Incorporated Metal‐Organic Framework with High Magnesium Ion Conductivity for Quasi‐Solid‐State Magnesium Batteries

Abstract

Abstract Magnesium batteries are promising candidates for post‐lithium energy storage systems due to their low cost, high volumetric energy density, and low risk of dendrite formation. This study reports a new magnesium ion conducting ionogel electrolyte based on a Metal‐Organic Framework (MOF) structure (UiO‐66) impregnated with an ionic liquid, magnesium bis[(trifluoromethyl)sulfonyl]imide in 1‐ethyl‐3‐methylimidazolium bis[(trifluoromethyl)sulfonyl]imide. Comparably high conductivity of 5.7×10 −5 S cm −1 can be achieved at room temperature. By employing the prepared MOF‐ionogel electrolyte, a reversible quasi‐solid‐state magnesium battery (QSSMB) is reported. Surface analysis unveils the possible origin of the large overpotential of magnesium plating and stripping. The findings suggest that MOF‐based materials are a promising class of ionogel electrolyte templates for QSSMBs. The results on the magnesium anode will be useful to define optimization strategies for magnesium metal anodes in SSMBs.