中文摘要：

利用石墨烯作为新型的阻挡层，设计并制备出具有核壳结构的石墨烯包覆多孔炭／硫复合材料，抑制锂硫电池中的“穿梭效应”，以提高正极材料的循环性能。该结构利用多孔炭材料作为储存硫的载体．而石墨烯作为阻挡层可以限制充放电过程中形成的多硫化物向体相电解液中的扩散，从而实现对正极材料的容量和循环性能的提高。此外，提出一种简便的组装方法来实现石墨烯在多孔炭／硫复合材料表面的包覆。利用氧化石墨烯在液相还原过程中官能团的去除来降低亲水性，从而使其自发地包覆在不亲水的多孔炭／硫复合材料表面，形成石墨烯包覆的核壳结构。

英文摘要：

Graphene is used as a barrier film to suppress the ＂shuttle effect＂ and to improve the performance of activated carbonsulphur 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.