Fabrication of CuO@NiMoO4 core-shell nanowire arrays on copper foam and their application in high-performance all-solid-state asymmetric supercapacitors

Hierarchical CuO@NiMoO4 core-shell nanowire arrays were directly fabricated on three-dimensional (3D) copper foam (CF) with a facile two-step route coupled with a post-thermal treatment. The optimized CuO@NiMoO4 composite electrode achieved a high capacitance of 2600.0 F g−1 (3.9 F cm−2) at a current density of 3 mA cm−2. Besides, an all-solid-state asymmetric supercapacitor (ASC) was assembled using the CuO@NiMoO4 electrode as positive electrode and activated carbon (AC) as the negative electrode, which exhibited a high energy density of 42.28 W h kg−1 at a power density of 631.57 W kg−1 and retained 24.8 W h kg−1 even at a high power density of 12763.4 W kg−1. Furthermore, the ASC device showed a high cycling performance with 90.4% retention of its initial capacitance after 5,000 constant charge-discharge process at a high current density of 10 mA cm−2. Two ASC devices were further employed as the energy source for a 5 mm light emitting diode (LED) that was lightened for more than 5 min, demonstrating its great potential in next-generation energy storage device applications. [Display omitted] •Hierarchical CuO@NiMoO4 core-shell nanowire arrays on copper foam was obtained.•The copper foam served as both current collector and reactant.•The core-shell nanostructure provided an intricate transportation network.•The ASC device achieved a high energy density of 42.28 W h kg−1.