Facile synthesis of Co3O4@MnO2 core-shell nanocomposites for high-performance supercapacitor

Co3O4@MnO2 core-shell arrays hybrid electrode directly grown on Ni foam for supercapacitor was obtained by two-step hydrothermal processes. Co3O4@MnO2 core-shell arrays hybrid electrode exhibited a high specific capacitance of 1920 F g−1 at current density of 1 A g−1. This was attributed to relative high conductivity of the Co3O4 nanowire arrays and the large surface area provided by the ultrathin MnO2 nanosheets. The porous MnO2 nanosheets stack provided numerous channels for rapid diffusion of electrolyte ions and fast electron transport, which enhanced the electrochemical reactions. The synergetic effect between Co3O4 nanowire and MnO2 nanosheets also improved the supercapacitor performance. In addition, the Co3O4@MnO2 core-shell arrangement also exhibited excellent cyclic stability.