Core-shell structured MnxCoyO4 @MoS2 composites for advanced electrodes in supercapacitors

Abstract

Supercapacitors are promising environmentally friendly energy storage devices owing to their high-power density, fast charge and discharge rates, long service life, wide applicable temperature range, and green environmental protection. Electrodes largely determine superconductor performance, so it is crucial to develop electrode materials with excellent performance. In this work, MnxCoyO4 @MoS2 composites were obtained by coating flake MoS2 arrays on spherical MnxCoyO4 using hydrothermal and heat treatment methods. At x/y = 1:2, the MnxCoyO4 @MoS2 electrode material exhibited a specific capacitance of 1422 F g−1 at 1 A g−1, which was higher than that at x/y = 1:1 and 2:1. When assembled into an aqueous asymmetric supercapacitor, the proposed electrode material provided a specific capacitance of 131 F g−1 at 1 A g−1. The promising cycle life of the electrode material was further illustrated by the fact that capacity retention of 85% was obtained after 5000 cycles, and the device retained a specific power of 794 W kg−1 with 46.58 Wh kg−1. The proposed electrode material design, therefore, provides new ideas to be used in the development of advanced electrodes.