Asymmetric supercapacitor based on VS2 nanosheets and activated carbon materials

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 similar to 99% capacitance retention and no capacitance loss after 5000 cycles at a current density of 2 A g(-1).