NiCo2S4@Ni3S2 hybrid nanoarray on Ni foam for high-performance supercapacitors
Integrated hybrid nanoarrays with hierarchical porous structures have attracted much attention as energy materials for their excellent synergistic effects. Herein, we provide a facile strategy for integrating a NiCo2S4@Ni3S2 hybrid nanoneedle array on nickel foam derived from metal–organic framework (MOF) precursors and a Ni/Co-precursor by sulfurization. When directly used as the free-standing electrode for a supercapacitor, the NiCo2S4@Ni3S2 electrode exhibited a high specific capacitance of 1536.8 F g−1 at 1 A g−1. Furthermore, the assembled NiCo2S4@Ni3S2//AC asymmetric supercapacitor (ASC) exhibited a high energy density of 35.26 W h kg−1 at a power density of 724.93 W kg−1. The capacitance retention of NiCo2S4@Ni3S2 was up to 97.4% after 10 000 cycles.