Hierarchical NiCo sub(2)O sub(4)nickel-sulfid e nanoplate arrays for high-performance supercapacitors

Electrodeposition of nickel sulfide (Ni-S) on NiCo sub(2)O sub(4) (NiCo sub(2)O sub(4)Ni-S) nanoplate arrays produces a new hierarchical core-shell functional-material. Weak crystalline Ni-S nanosheets have been uniformly coated on the NiCo sub(2)O sub(4) nanoplate array obtained by hydrothermal growth. When tested as an electrode for supercapacitors, the NiCo sub(2)O sub(4)Ni-S nanoplate arrays have been found to exhibit a significantly improved areal capacitance of 1.85 F cm super(-2) at a current density of 8 mA cm super(-2), good rate capability and cycling stability. In addition, the capacitance fading of the NiCo sub(2)O sub(4)Ni-S arrays are attributed to the surface coarsening of the Ni-S nanosheets.