Effective Ways to Stabilize Polysulfide Ions for High‐Capacity Li−S Batteries Based on Organic Chalcogenide Catholytes

Abstract

AbstractGiven the great promise of lithium‐sulfur (Li−S) batteries as next‐generation high‐capacity energy storage devices, this feature article investigated critical parameters of the cathode, such as pretreatment of elemental sulfur (sublimed, polymerized, and crystallized), size of sulfur particles (19 vs. 35 μm) and aptness of current collector (aluminium vs. carbon paper). At the same time it also demonstrated the applicability of polychalcogenide‐based catholytes (e. g., diphenyl disulfide and diselenide) that exhibited a record specific capacity (3000 mAh g−1 at a C/5 rate) and an energy density of 1853 Wh Kg−1. From tweaking the sulfur nature in the cathode, where small‐sized polymerized sulfur was found to promote the carbon‐sulfur bond on the surface of carbon nanotubes, to trapping the polysulfide ions to formulate organochalcogenide‐based catholytes, our study provided fundamental insights into key battery performance parameters as well as sulfur‐polysulfide electrochemistry, inspiring future designs of such battery systems and more.