Excellent Electrochemical Performance Hierarchical Co3O4@Ni3S2 core/shell nanowire arrays for Asymmetric Supercapacitors

• 3D hierarchical Co3O4@Ni3S2core(*)/shell nanowire arrays were designed and fabricated.
• A facile two-step route containing hydrothermal and electrodeposition method was applied.
• The Co3O4@Ni3S2//AC asymmetric supercapacitor was successfully assembled and the high energy and power density were achieved.

Three-dimensional hierarchical Co3O4@Ni3S2 core/shell nanowire arrays were designed and fabricated on nickel foam via a facile two-step route for supercapacitor applications. Compared with the pristine Co3O4 nanowire arrays and Ni3S2 nanosheets, the hierarchical nanostructure demonstrates much more excellent capacitive behaviors. The Co3O4@Ni3S2 electrode exhibited an ultrahigh specific capacitance of 1710 F g−1 at 1 A g−1 and 1474 F g−1 at 10 A g−1. An asymmetric supercapacitor based on Co3O4@Ni3S2 core/shell nanowire arrays on nickel foam as the positive electrode and activated carbon (AC) as negative electrode was successfully assembled. A specific capacitance of 126.6 F g−1 at 1 A g−1 (retaining 83.5% capacity after 5000 cycles at a current density of 2 A g−1) and an outstanding energy density of 44.9 Wh kg−1 was achieved. The remarkable electrochemical properties could be attributed to the unique hierarchical architectures of Co3O4@Ni3S2 core–shell nanowire arrays on 3D on nickel foam and a rational combination of two electrochemical pseudocapacitor materials. The results indicate that our asymmetric supercapacitors have great potential in energy storage device applications.