Electrolyte Evolution Propelling the Development of Nonlithium Metal-Sulfur Batteries

Metal-sulfur batteries with sulfur cathodes and light-weight metal anodes are promising next-generation energy-storage systems for their high specific capacities, high energy densities, high abundance, and potentially low cost of the electroactive materials. In the development of various metal-sulfur batteries, the electrolyte plays a central role. The electrolyte significantly affects the capacity, cycling performance, safety, and rate capability. This article reviews the recent development of the electrolyte technology applied in nonlithium metal-sulfur batteries of Na-S, K-S, Mg-S, and Al-S, in comparison with the Li-S battery electrolytes. The evolution of the electrolyte technology and how it propels the advancement of the rechargeable metal-sulfur batteries are highlighted. Finally, several considerations are given for evaluating the nonlithium metal-sulfur battery electrolytes from a practical point of view.