▎ 摘　　要

An effective method was used to produce stable and homogeneous colloidal suspensions of highly reduced graphene oxide (RGO) in N, N-dimethylformamide (DMF) without the assistance of dispersing agents. According to the results of general characterization, relatively pure graphene sheets with the morphology of single layer or few-layer structure were obtained. Then nanocomposite powders of RGO and poly (vinylidene fluoride) (PVDF) were prepared by vacuum filtration of the mixed dispersions of both components. The nanocomposites exhibit a high-frequency capacitative response with small equivalent series resistance (ESR) at 0.4 Omega, a nearly rectangular cyclic voltammogram and possess a rapid current response as electrodes for super-capacitor in 5 mol/L KOH electrolyte. Furthermore, after 600 galvanostatic charge/discharge cycles, the supercapacitor still performs a very high stability and efficiency of capacitance.