▎ 摘　　要

This study reports the direct preparation of graphene-based films using magnetron sputtering of graphite target. The nanomaterial was deposited at a low temperature of 620 degrees C on silicon wafers and on metallic foils including aluminum. The films were used in fabrication of supercapacitors with a planar geometry. Electrochemical characterizations demonstrated that the films produced showed nearly ideal electrical capacitive behavior. The maximum capacitance obtained from cyclic voltammetry analysis was 325 F/g for a scan rate of 1 mV/s. The device is capable of delivering an energy density of 13.9 Wh/kg at a very high power density of 50 000 W/kg for ultrafast scan rate of 1000 mV/s. The graphene nanomaterial electrode retains the electrochemical stability over a large number of charge-discharge cycles.