Fabrication of an Advanced Asymmetric Supercapacitor Based on Three-Dimensional Copper-Nickel-Cerium-Cobalt Quaternary Oxide and GNP for Energy Storage Application

We demonstrate a cost-effective synthesis of 3D quaternary copper nickel cerium cobalt oxide (Cu-Ni-Ce-Co oxide) through a one-step hydrothermal protocol followed by a heat treatment process. The mesoporous Cu-Ni-Ce-Co oxide (with pore diameter 4.34 nm) shows a higher specific surface area (86.9 m(2) g(-1)). The as-synthesized quaternary oxide provides an ultrahigh specific capacitance of 2696 F g(-1) at 1 A g(-1) along with a moderate cycle stability of 86.5% after 3000 charge discharge cycles. Furthermore, an asymmetric supercapacitor (ASC) was established by assembling Cu-Ni-Ce-Co oxide and graphene nanoplatelets (GNP) as positive and negative electrode materials, respectively, and the supercapacitor performances were executed thoroughly. The ASC delivers a remarkable energy density of approximate to 51 Wh kg(-1) at a power density of 581.9 W kg(-1) together with long-term cyclic stability (92% specific capacitance retention after 3000 cycles). The compositional and morphological features together with superior electrochemical properties can make it advantageous for practical use in energy and power applications.