Facile and Effective Strategy to Encapsulate Sulfur Particles for High-Performance Lithium–Sulfur Battery

A sulfur composite (poly@S) was prepared by in situ encapsulating the copolymer of 1,3-dioxolane (DOL) and trioxymethylene (TOM) (poly(DOL- co -TOM)) on the surface of S particles, which was used as cathode material for Li–S battery. The poly(DOL- co -TOM) copolymer has high ionic conductivity and excellent tensile properties, which can promote reaction kinetics and stabilize the cathode structure. The ultrathin encapsulation layer (∼40 nm) can effectively confine the polysulfides and alleviate the “shuttle effect”. The Li–S battery assembled with the poly@S composite cathode shows outstanding cycle stability (a low decay rate of about 0.079% per cycle at 0.5 C over 400 cycles) and excellent C -rate performance. Moreover, the self-discharge has been effectively restricted by inhibiting the shuttling of polysulfides. This work creatively proposes a facile and effective strategy to prepare a composite S cathode for high-performance Li–S batteries.