Synthesis of Co3O4/SnO2@MnO2 core-shell nanostructures for high-performance supercapacitors

Here, we develop a novel and cost-effective design of hierarchical Co3O4/SnO2@MnO2 core-shell nanostructures to serve as high-performance electrodes for supercapacitors. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) measurements indicate that ultrathin MnO2 nanosheets uniformly deposit on the surface of the Co3O4/SnO2 nanobox, as a result, forming a core-shell structure. These unique well-designed electrodes exhibit a high specific capacitance (225 F g(-1) at a current density of 0.5 A g(-1)), a good rate capability (62.2% capacitance retention), and an excellent cycling stability (90.7% retention after 6000 cycles). We believe that this facile strategy to fabricate the core-shell structure with significantly improved electrochemical properties opens up new opportunities to design a high-performance MnO2-based nanocomposite for constructing next-generation supercapacitors.