The ultralong cycle life of solid flexible asymmetric supercapacitors based on nickel vanadium sulfide nanospheres

The nickel vanadium sulfide electrodes shows an capacitance of 697.4 C g⁻¹ at current density of 1A g⁻¹. The flexible ACS Ni–V–S–2//rGO gives rise to a remarkable cyclic stability with 100% capacitance retention over 7000 charge–discharge cycles.