Self-Supported CoO@Mo-CoO Needle-like Nanosheet Heterostructured Architectures of Battery-Type Electrodes for High-Performance Asymmetric Supercapacitors.

Herein, this report uses CoO nanoneedles to decorate Mo-CoO nanosheets over Ni foam, which were fabricated by the hydrothermal route, in order to create a supercapacitor material which is compared with its counterparts. The surface morphology of the developed material was investigated through scanning electron microscopy and the structural properties were evaluated using XRD. The charging storage activities of the electrode materials were evaluated mainly by cyclic voltammetry and galvanostatic charge-discharge investigations. In comparison to binary metal oxides, the specific capacities for the composite CoO@Mo-CoO nanosheets and CoO nano-needles were calculated to be 814, and 615 C g at a current density of 1 A g, respectively. The electrode of the composite CoO@Mo-CoO nanosheets displayed superior stability during 4000 cycles, with a capacity of around 90%. The asymmetric CoO@Mo-CoO//AC device achieved a maximum specific energy of 51.35 Wh Kg and power density of 790 W kg. The CoO@Mo-CoO//AC device capacity decreased by only 12.1% after 4000 long GCD cycles, which is considerably higher than that of similar electrodes. All these results reveal that the CoO@Mo-CoO nanocomposite is a very promising electrode material and a stabled supercapacitor.