Progress on high-energy density lithium-sulfur batteries

Recently, lithium-sulfur batteries as high energy-density energy storage system have attracted more and more attention. In this article, we first introduce lithium-sulfur batteries and then review recent progress in carbon-sulfur cathodes and electrolytes for lithium-sulfur batteries. Furthermore, we analyze and summarize the reported strategies to inhibit "lithium polysulfide dissolution". Particularly, we propose a new class of bi-functional "Solvent-in-Salt" (SIS) electrolyte with high lithium salt concentration for solving the problems resulting from both sulfur and lithium metal electrodes. Finally, we present the outlook for future lithium-sulfur batteries.