We report a direct growth of a polyhedral CuO core covered with the double shells, consisting of an ultrathin carbon layer as an interfacial bridge and MnO2 nanoflakes as an external surface (abbr.CuO@C@MnO2) on Ni foam skeleton to assemble an all-solid-state supercapacitor with a large specific capacitance and long-term stability. The hierarchical design can utilize the intrinsic characteristics and space structure features of each component to expose the highly active facets of CuO polyhedrons, enhance the interface interaction between CuO core and MnO2 shell using the ultrathin carbon layer, and improve the surface area by the fluffy MnO2 nanoflakes. The all-solid-state supercapacitor based on the optimized CuO@C@MnO2-coated Ni foam electrode shows a high energy density of 81 Wh kg(-1) at a power density of 3326 W kg(-1). The specific capacitance of the device still kept at about 98.6 F g(-1) after 5000 charge/discharge cycles at a current density of 2.7 A g(-1), revealing an excellent reversibility with only about 1% loss. The core/double-shell supercapacitors are expected to be a high capacitance, excellent reversible and quite stable for a long-lived cycling. (C) 2017 Elsevier Ltd. All rights reserved.