Electrolyte Issues in Lithium–Sulfur Batteries: Development, Prospect, and Challenges

Lithium–sulfur (Li–S) batteries have attracted great attention in the past two decades, because of their high theoretical energy density of 2600 Wh kg –1 and the cost-effective sulfur cathode. However, it is still far from commercialization, unlike that of lithium-ion batteries. Although numerous research has been presented on the sulfur cathode, lithium metal anode, separator modification, intercalated layer within the cell configuration, electrolyte design, the problematic issues of the polysulfide shuttling effect cannot be solved effectively. In this Review, we summarize that most challenges in the Li–S battery have involved the electrolyte. The development of Li–S battery electrolytes was discussed from the components of salt, solvent, additives, then the current idea of electrolyte designs including the solid electrolytes was also summarized. This Review aims to give a comprehensive and depth viewpoint on the development, prospect, and challenges of Li–S battery electrolytes.