Fabrication of hierarchical core/shell MgCo₂O₄@MnO₂ nanowall arrays on Ni-foam as high-rate electrodes for asymmetric supercapacitors.

ABSTRACT: Design and fabrication of a hierarchical core/shell MgCo₂O₄@MnO₂ nanowall arrays on Ni-foam by a facile two-step hydrothermal method. The electrochemical measurements prove these composites with MnO₂ definitely offer better supercapacitive performance of the MgCo₂O₄ electrode material. The nanowall structure provides more active sites and charge transfer during the Faradic reaction. The MgCo₂O₄@MnO₂ nanowall shows an excellent electrochemical performance (852.5?F?g^-1 at 1?A?g^-1). The asymmetric supercapacitor is composed of the MgCo₂O₄@MnO₂ nanowall and the activated carbon (AC). The energy densities of the asymmetric supercapacitor device can keep up 67.2?Wh·kg^-1 at 5760.0?W·kg^-1. The MgCo₂O₄@MnO₂ nanowall shows excellent supercapacitive performance and has a great potential for more research and application in the asymmetric supercapacitor devices field.

SUBMITTER: Xu J 

PROVIDER: S-EPMC6715631 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature