Hierarchical CuCo2O4@nickel-cobalt hydroxides core/shell nanoarchitectures for high-performance hybrid supercapacitors

Ni0.5Co0.5(OH)2 nanosheets coated CuCo2O4 nanoneedles arrays were successfully designed and synthesized on carbon fabric. The core/shell nanoarchitectures directly served as the binder-free electrode with a superior capacity of 295.6 mAh g−1 at 1 A g−1, which still maintained 220 mAh g−1 even at the high current density of 40 A g−1, manifesting their enormous potential in hybrid supercapacitor devices. The as-assembled CuCo2O4@Ni0.5Co0.5(OH)2//AC hybrid supercapacitor device exhibited favorable properties with the specific capacitance as high as 90 F g−1 at 1 A g−1 and the high energy density of 32 Wh kg−1 at the power density of 800 W kg−1. Furthermore, the as-assembled device also delivered excellent cycling performance (retaining 91.9% of the initial capacitance after 12,000 cycles at 8 A g−1) and robust mechanical stability and flexibility, implying the huge potential of present hierarchical electrodes in energy storage devices.