Constructing high-capacitance electrochemical capacitors through the introduction of V ions into MoS2/Ni3S2 nanosheets

Designing the electrode materials with high energy density is crucial to improve the total performance of supercapacitors. In this work, we report V-doped MoS2/Ni3S2 nanosheets grown on nickel foam by a convenient hydrothermal route. Due to the large specific surface area and rapid ion migration rate, the obtained 0.07V–MoS2/Ni3S2 composites deliver a specific capacitance of 960C/g at 1 A/g. After cycling 10,000 times, they still remain at 71.65% of the initial capacity. Several asymmetric supercapacitors are assembled using the above samples as cathode materials. They achieve an energy density of 75 Wh/kg at a power density of 2700 W/kg. This work provides a feasible strategy to construct high-performance transition metal compound electrode materials in future flexible energy storage electronics.