Porous Co3S4@Ni3S4 heterostructure arrays electrode with vertical electrons and ions channels for efficient hybrid supercapacitor

Abstract Faradic electrodes with large specific surface areas, efficient electrons/ions migration channels and high redox activities are essential prerequisites for high performance supercapacitors. Herein, highly porous Co 3 S 4 @Ni 3 S 4 heterostructure arrays were prepared onto Ni foam substrate by a facile two-step hydrothermal route for application as supercapacitor electrode. Because of the novel core-sheath heterostructure with vertically aligned porous nanowires arrays and macroporous channels, the Co 3 S 4 @Ni 3 S 4 electrode can offer high electrons/ions mobilities and large specific surface area, therefore enables an areal capacitance ( C A ) of 3.6 F cm −1 at 0.8 mA cm −2 and 80% initial C A maintaining ratio undergoes 5000 consecutive charge-discharge cycles. When used as positive electrode of hybrid supercapacitor, the lightweight Co 3 S 4 @Ni 3 S 4 //porous carbon hybrid supercapacitor delivers an areal capacitance of 0.513 F cm −2 at 2 mA cm −2 and moderate rate capability, therefore can deliver areal energy densities of 0.19–0.021 mWh cm −2 within areal power density range of 1.72–38.4 mW cm −2 , good cycleability and slow self-discharge behavior. The current Co 3 S 4 @Ni 3 S 4 heterostructure arrays electrode paves a feasible avenue to improve the capacitive performances of supercapacitors through construction of hierarchically porous nanoarrays architectures.