Short-Chain Polyselenosulfide Copolymers as Cathode Materials for Lithium–Sulfur Batteries

Copolymerization of sulfur, which forms sulfur-rich polymers, has recently opened a new era in the lithium–sulfur (Li–S) battery research as improved battery performances could be achieved compared to pure sulfur (S 8 ). By means of organic chemistry, sulfur copolymers with desired features and chemical structures could be rationally designed and synthesized. In this study, sulfur-rich polymers consisting of short-chain tetrasulfide (R-S 4 -R) (PTS) and selenotrisulfide (R-SeS 3 -R) (PTSeS) bonds are suggested as cathode materials for Li–S batteries. Intrinsically short poly(seleno)sulfide bonds along with covalent anchoring effect effectively suppress the parasitic shuttle effect originating from soluble long-chain lithium polysulfides formed from pure S 8 . Furthermore, a comparative study demonstrates the indisputable advantage of the selenium doping, which enhances the electrical con…