Asymmetric supercapacitor based on VS2 nanosheets and activated carbon materials

Abstract

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.