High specific capacity composite cathode materials for lithium-sulfur batteries

Because the complete reaction product of lithium and sulfur is Li2 S, the theoretic capacity of elemental sulfur cathode in a lithium sulfur battery is 1675mA·h/g, which is much higher than other cathode materials of LiFePO4, LiCoO2, et al. And sulfur has low price and non-toxic, which is an ideal cathode material. However, its electrical conductivity is very low, and the capacity declines rapidly with cycling. So it is necessary to improve the conductive performance of sulfur cathode and enhance its electrochemical properties. In this paper, the preparation method, structure and morphology, electrochemical properties of sulfur-based composite cathode materials are reviewed. The combination of sulfur with mesoporous carbon, CNTs graphene and polypyrrole respectively is discussed, and the future prospect of sulfur-based cathode material is also represented.