Structure and reactions mechanism of sulfurized polyacrylonitrile as cathodes for rechargeable Li-S batteries

Sulfurized polyacrylonitrile (S@pPAN) composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batteries because of its outstanding electrochemical performances via novel solid–solid conversion mechanism. Although there are a great number of researches on the S@pPAN composite material, the accurate structure of S@pPAN and its redox reaction mechanism during the charge–discharge process still have not been determined. The previous research and inferences about the structure of S@pPAN and its electrochemical reaction mechanism were summarized in this review, providing a reference for the future study of lithium-sulfur batteries.