Graphene-Wrapped Sulfur Particles as a Rechargeable   Lithium-Sulfur-Battery Cathode Material with High Capacity and Cycling   Stability
  We report the synthesis of a graphene-sulfur composite material by wrapping polyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidized graphene oxide sheets decorated by carbon black nanoparticles. The PEG and graphene coating layers are important to accommodating volume expansion of the coated sulfur particles during discharge, trapping soluble polysulfide intermediates and rendering the sulfur particles electrically conducting. The resulting graphene-sulfur composite showed high and stable specific capacities up to ~600mAh/g over more than 100 cycles, representing a promising cathode material for rechargeable lithium batteries with high energy density. 
Hailiang Wang, Yuan Yang, Yongye Liang, Joshua Tucker Robinson,   Yanguang Li, Ariel Jackson, Yi Cui and Hongjie Dai
cond-mat.mtrl-sci