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

Abstract

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.