Preparation and electrochemical performance of a graphene-wrapped carbon/sulphur composite cathode

Graphene is used as a barrier film to suppress the “shuttle effect” and to improve the performance of activated carbon–sulphur hybrid cathode materials in a lithium-sulphur battery by forming a core–shell structure. Graphene wraps around the activated carbon–sulphur hybrid to form a core–shell structure, in which the porous carbon framework stores most of the sulphur and the graphene layer suppresses the movement of the soluble polysulfide in the electrolyte during charge–discharge, resulting in an improvement of capacity and cyclic stability during long-term cycling. Such a core–shell structure is formed by changing the hydrophilicity of graphene oxide during reduction, in which the hydrophobic graphene closely wraps around the hydrophobic carbon surface. arbon Materials 2014, 29(4): 309–315]