Asymmetric supercapacitor based on VS2 nanosheets and activated carbon materials

Abstract

VS2 nanosheets as the positive electrode and the activated carbon (AC) as the negative electrode with a 6 M KOH solution as electrolyte were fabricated as an asymmetric supercapacitor. These materials were combined to maximize the specific capacitance and to enlarge the potential window, therefore improving the energy density of the device. A specific capacitance of 155 F g-1 at 1 A g-1 with a maximum energy density as high as 42 Wh kg-1 and a power density of 700 W kg-1 was obtained for the asymmetric supercapacitor within the voltage range of 0 – 1.4 V. The supercapacitor also exhibited a good stability with ∼ 99% capacitance retention and no capacitance loss after 5000 cycles at a current density of 2 Ag-1.