Magnesium Cobaltate Nanowires@magnanese Dioxide Nanoflakes Core-Shell Arrays on Graphene-Decorated Nickel Foam for High-Performance Supercapacitors

In this work, MgCo2O4 nanowires@MnO2 nanoflakes core-shell arrays structure on graphene-decorated nickel foam were successfully prepared, which were featured by porous MnO2 nanoflakes shell and one-dimensional MgCo2O4 nanowires core directly grown on the graphene. The morphologies of MgCo2O4 nanowires@MnO2 nanoflakes core-shell arrays can be tuned by changing the hydrothermal reaction times. Due to the synergistic effect of graphene, MgCo2O4 nanowires, and MnO2 nanoflakes, the optimized MgCo2O4 nanowires@MnO2 nanoflakes core-shell arrays electrode materials exhibited excellent electrochemical performance such as high specific capacitances of 887.3 F g(-1) at a current density of 1 A g(-1) and good long-term cycling stability over 3000 cycles at a high current density of 10 A g(-1). The findings reported here clearly demonstrated that the core-shell arrays structure may be a promising candidate of high-performance electrode materials for supercapacitor.