An asymmetric supercapacitor was fabricated using VS2 nanosheets as the positive electrode and activated carbon (AC) as the negative electrode, with a 6 M KOH solution as electrolyte. These materials were combined to maximize the specific capacitance and 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 W h 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 good stability, with ∼99% capacitance retention and no capacitance loss after 5000 cycles at a current density of 2 A g−1.
