A Review of Advanced Energy Materials for Magnesium–Sulfur Batteries

Magnesium–sulfur batteries promise high volumetric energy density, enhanced safety, and low cost for electrochemical energy storage. The current obstacles to practical applications of reliable magnesium–sulfur batteries are finding electrolytes that can meet a multitude of rigorous requirements along with efficient sulfur cathodes and magnesium anodes. This review highlights recent advances in designing better electrolytes, cathodes, and anodes. A suitable electrolyte for magnesium–sulfur batteries should allow to reversibly electroplate/strip divalent magnesium ions and should be compatible with the sulfur cathode and the other cell's components. Another challenge to be addressed is the careful engineering of the interface and microstructure in the sulfur scaffold to effectively mitigate the soluble magnesium polysulfide shuttle and to enhance the reaction kinetics. We highlight that the ongoing research in this field encourages the fundamental understanding of the reaction mechanisms and the interplay among the different components by diverse characterization techniques.