Graphene-Wrapped Sulfur Particles as a Rechargeable Lithium-Sulfur-Battery Cathode Material with High Capacity and Cycling Stability

摘要

We report the synthesis of a graphene-sulfur composite material by wrappingpolyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidizedgraphene oxide sheets decorated by carbon black nanoparticles. The PEG andgraphene coating layers are important to accommodating volume expansion of thecoated sulfur particles during discharge, trapping soluble polysulfideintermediates and rendering the sulfur particles electrically conducting. Theresulting graphene-sulfur composite showed high and stable specific capacitiesup to ~600mAh/g over more than 100 cycles, representing a promising cathodematerial for rechargeable lithium batteries with high energy density.