Encapsulation of hollow Cu2O nanocubes with Co3O4 on porous carbon for energy-storage devices

Abstract Co3O4 is one of the most studied transition-metal oxides for use in energy-storage devices. However, its poor conductivity and stability limit its application. In this study, a facile method for anchoring Co3O4-encapsulated Cu2O nanocubes on porous carbon (PC) to form Cu2O@Co3O4/PC was developed. The Cu2O@Co3O4/PC composite exhibited superior electrochemical performance as a supercapacitor electrode material. The resultant supercapacitor delivered high specific capacitance (1096 F g−1 at 1 A g−1), high rate capability (83 % retention at 10 A g−1), and excellent cycling stability (95 % retention of initial capacitance after 3000 cycles). Moreover, an asymmetric supercapacitor fabricated by coupling a Cu2O@Co3O4/PC positive electrode with a reduced graphene oxide negative electrode exhibited high energy density (32.1 W h kg−1 at 700 W kg−1). Thus, our results demonstrate that Cu2O@Co3O4/PC is a promising electrode material for energy-storage devices.