A new hybrid nanostructure of porous cobalt monoxide nanowire @ ultrathin nickel hydroxidenitrate nanoflake is directly synthesized on a 3D nickel foam by a facile two-step hydrothermal route, which demonstrates a specific capacitance of ∼798.3 F g−1 at the current density of ∼1.67 A g−1 and good rate performance when used as electrode material for supercapacitors. The capacitance loss is less than 5% after 2000 charge–discharge cycles.
