Electrochemical energy storage application of CuO/CuO@Ni–CoMoO4·0.75H2O nanobelt arrays grown directly on Cu foam

Supercapacitors are attracting huge research interest because they are expected to achieve battery-level energy density, and they have a longer calendar life and shorter charging time. However, due to the out shell materials without contact extra freeway for charge transports, the out shell materials have still limited contribution to high capacitance for array structure at high rates. Here, CO/CO@Ni-CMO NBs were designed and synthesized on Cu foam substrates with CuO NBs as cores or extra freeway and Ni–CoMoO4·0.75H2O nanobelt as shell by an easily synthetic method. CuO NBs will provide electron “superhighways” and extra outside freeway for charge storage and delivery. Besides, the Ni doped CoMoO4·0.75H2O NBs are conducive to the electrical conductivity, and open space among these nanosheets can act as an “ion reservoir”, the increment of active sites and the contribution of capacitive effects. Finally, the CO@Ni-CMO NBs directly grown on Cu foam could avoid the “dead” volume caused by the tedious process of mixing active materials with polymer binders/conductive additives. As expected, the CO/CO@Ni-CMO NBs exhibited the high specific capacitance, the good rate performance and the excellent electrochemical stability. We synthesized CuO/CuO@Ni–CoMoO4·0.75H2O nanobelt arrays with CuO nanobelt arrays inside Ni–CoMoO4·0.75H2O nanosheets and the parts of CuO nanobelt arrays without wrapped Ni–CoMoO4·0.75H2O nanosheet, which exhibited the high specific capacitance and the excellent electrochemical stability. [Display omitted] •CuO nanobelt arrays inside Ni–CoMoO4·0.75H2O nanosheets provide electron “superhighways”.•CuO nanobelt arrays without wrapped Ni–CoMoO4·0.75H2O nanosheets decrease electron aggregation.•The arrays structure and open space among these nanosheets avoid the “dead” volume and allows easy diffusion of the electrolyte.•The Ni doped is conducive to the electrical conductivity and the increment of active sites.