Self-Supported Co₃O₄@Mo-Co₃O₄ Needle-like Nanosheet Heterostructured Architectures of Battery-Type Electrodes for High-Performance Asymmetric Supercapacitors

Herein, this report uses Co₃O₄ nanoneedles to decorate Mo-Co₃O₄ 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 Co₃O₄@Mo-Co₃O₄ nanosheets and Co₃O₄ nano-needles were calculated to be 814, and 615 C g^-1 at a current density of 1 A g^-1, respectively. The electrode of the composite Co₃O₄@Mo-Co₃O₄ nanosheets displayed superior stability during 4000 cycles, with a capacity of around 90%. The asymmetric Co₃O₄@Mo-Co₃O₄//AC device achieved a maximum specific energy of 51.35 Wh Kg^-1 and power density of 790 W kg^-1. The Co₃O₄@Mo-Co₃O₄//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 Co₃O₄@Mo-Co₃O₄ nanocomposite is a very promising electrode material and a stabled supercapacitor.