A facile one-pot hydrothermal synthesis of Co₉S₈/Ni₃S₂ nanoflakes for supercapacitor application

Co₉S₈/Ni₃S₂ nanoflakes have been successfully designed and constructed on a nickel foam substrate via a simple one-pot hydrothermal synthesis. The as-prepared Co₉S₈/Ni₃S₂ active electrode exhibited superior supercapacitor performance with an area capacitance of 8.95 F cm⁻² at a current density of 6 mA cm⁻², and 7.80 F cm⁻² even at a high power density of 12 mA cm⁻². By applying Co₉S₈/Ni₃S₂ as the positive electrode and porous carbon as the negative electrode, an asymmetric supercapacitor device was fabricated and has shown promising energy densities of 81.7 W h kg⁻¹ at a power density of 0.35 kW kg⁻¹. The stupendous specific capacitance, enhanced cycle stability, elevated energy density and power density as an asymmetric supercapacitor device of these electrode materials indicate that they could be a potential candidate in the field of supercapacitors.