A graphene/nano-sulfur (RGO/nano-S) cathode composites was prepared by chemical precipitation of nano-sulfur onto graphene sheets

which were synthesized by pyrolyzing reduction of graphene oxide from Hummers method. The microscopic structure and morphology of the composites were characterized by FT-IR

XRD

SEM

TEM and Raman

while the electrochemical properties were studied by galvanostatic charge-discharge measurements

cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that wrinkled surface on the thermally reduced graphene created a space to accommodate sulfur and polysulfur ions

which helped to hinder dissolving of active cathode materials and suppress migration of polysulfide ions. A homogeneous distribution of nano-sulfur in the graphene conductive network significantly enhanced the effective contact with electrolyte and increased electrochemical reaction area

so that improved discharge capacity and cycle-life performance of the lithium-sulfur batteries.