The Metamorphosis of Mg(SO₃CF₃)₂‐based Electrolytes for Rechargeable Magnesium Batteries

Abstract

Cost‐effective, non‐corrosive and non‐nucleophilic Mg(SO3CF3)‐based electrolytes with high anodization stability are promising candidates for realizing high‐performance rechargeable magnesium batteries (RMBs). Since the 1990s, the community has developed polymer‐based, room‐temperature molten salt‐based, chlorine‐containing and chlorine‐free electrolyte systems using Mg(SO3CF3)2 as the simple magnesium salt. However, there is currently a lack of overall understanding of the metamorphosis of Mg(SO3CF3)2‐based electrolytes. This survey reviews the development of various branches of Mg(SO3CF3)2‐based electrolytes, with a special focus on strategies to improve electrolyte performance. First, the utilization of various polymer matrices, room‐temperature molten salts, inorganic/organic chlorine salts and chelating ligands to promote the performance of Mg(SO3CF3)2‐based (quasi‐)solid and liquid electrolytes is outlined. Subsequently, combining the passivation nature of Mg(SO3CF3)2 and polar aprotic solvents toward the Mg anode and the current improvement strategies, the future challenges and opportunities of Mg(SO3CF3)2‐based electrolytes in various branches are discussed. These summaries and discussions will provide guidelines for the development of Mg(SO3CF3)2‐based electrolytes with desirable properties for RMBs.