Substituting copolymeric poly(alkylenetetrasulfide) for elemental sulfur to diminish the shuttling effect of modified intermediate polysulfides for high-performance lithium–sulfur batteries

Abstract

Poly(alkylenetetrasulfide) can be synthesized to replace sulfur in a chitosan-derived porous carbon (CPC) based composite cathode of lithium–sulfur batteries. Introducing a –CH₂– or –CH₂CH₂– unit in-between the S–S bond of a polysulfide (e.g., Li₂S₄ → Li–S₂–CH₂–S–Li or Li–S–CH₂CH₂–S–Li) diminishes the adverse shuttling effect, proved by experimental tests and first-principle calculations.