Optimal Sulfur Content Study on Electrochemical Properties of Graphene Nanosheets/Single-Walled Carbon Nanotube Composite Electrodes

Graphene nanosheets (GNS)/sulfur were synthesized by heating a mixture of GNS and elemental sulfur. Single-walled carbon nanotubes (SWCNTs) were added into the composites as a modifier on GNS layers. The embedment of SWCNTs into composites can inhibit agglomeration of GNS and increase an effective surface area of the structural electroactive sites. The electrochemical property of the composites was investigated using cyclic voltammetry (CV), charge-discharge curves and cycle performance. The micro-structure and morphology of the composites were examined by scanning electron microscopy (SEM), transition electron microscopy (TEM). The GNS/SWCNT/sulfur composites exhibited the improved current density of redox reaction and the cycle stability for an application of rechargeable lithium-sulfur cells.