The graphene nanosheet(GNS)/CoS2 composite was prepared by the one-step hydrothermal method. The crystal structure and morphology were characterized by XRD and SEM. Electrochemical properties were determined by cyclic voltammetry and electrochemical impedance spectroscopy. Graphite oxide (GO) was gradually reduced to form graphene nanasheet during the hydrothermal process

which could provide abundant contact sites for the formation of CoS2 crystal nucleus

thus leading to uniform distribution of CoS2 particles on the surface of graphene. Such novel structure composite not only significantly enhanced the effective contact area between CoS2 and electrolyte

but also improved electrochemical utilization of CoS2 electrode materials. Meanwhile

it facilitated electrical conductivity of the material

resulting in increased specific capacitance.