Review—The Importance of Chemical Interactions between Sulfur Host Materials and Lithium Polysulfides for Advanced Lithium-Sulfur Batteries

This overview details the recently recognized importance of strong chemical interactions between sulfur host materials and lithium polysulfides/sulfide to improve the performance of Li-S batteries, especially with respect to cycle life. Sulfur hosts consisting of: functionally modified surfaces, metal oxides and carbides that rely on either polar interactions or the thiosulfate mechanism for sulfide binding, metal-organic frameworks that exhibit Lewis-acid behavior, and functional polymers are reviewed. We summarize a variety of studies that explore the nature and strength of the interaction of these materials with polysulfides and its effect on cycle life, showing that capacity fading is reduced to as low as 0.03% per cycle with effective functional cathode host surfaces.