In this paper, hierarchical Co3O4-SnO@SnO2 nanostructures flexible supercapacitor electrodes were fabricated by hydrothermal routine. Owing to the introduction of Co3O4 as well as a cleverly PN junction hierarchically skeleton, the Co3O4-SnO@SnO2 electrode presents a structure of nanospheres covered by nanoparticles, offering a low internal resistance (0.6 Omega) and high electrical conductivity. Without the use of a binder and complicated manufacturing process, the hierarchical nanostructures can be directly used as the working electrode in the three-electrode system. In addition, the electrode demonstrates a high specific capacitance (1.056 F cm(-2) at 1 mA cm(-2)) and excellent stability (only 8.5% was lost in initial specific capacitance at 1 mA cm(-2) after 2000 cycles). Therefore, the hierarchical Co3O4-SnO@SnO2 nanostructures provide an opportunity for the coordinated development of novel energy density and power density of supercapacitor. (C) 2019 Elsevier Ltd. All rights reserved.