Three-Dimensional Co3 O4 @NiCo2 S4 Core/Shell Nanoflower Array with Enhanced Electrochemical Performance

In this paper, we fabricated a unique three-dimensional Co3O4@NiCo2S4 core-shell nanoflower array supported on Ni foam. The Co3O4@NiCo2S4 core-shell structure shows remarkable electrochemical property. The as-prepared electrode exhibits 1234 F g−1 of specific capacitance at a current density of 1 A g−1 with a maximum energy density up to 168 W h kg−1. Besides, there is only about 11% lose of initial specific capacitance after 5000 cycles. Such excellent electrochemical performance of the hybrid Co3O4@NiCo2S4 core-shell nanoflower array is attributed to the unique configuration and the strong synergistic effect of the porous Co3O4 core and the ultrathin NiCo2S4 shell. The materials were used as the electrodes of symmetric supercapacitor, presenting many excellent properties. Above all, it owns high energy density of 40.25 W h kg−1 even at a power density of 6300 W kg−1.