Ternary MnCo2O4/MWCNT/rGO nanocomposites as high-performance supercapacitor electrode materials

Abstract

In this research, MnCo2O4 nanoparticles and their composites with reduced graphene oxide (rGO), multi-wall carbon nanotube (MWCNT), and MWCNT/rGO were synthesized by a simple hydrothermal method to investigate their performance as supercapacitor electrodes. The crystal structure and morphology of the fabricated materials were studied through X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. Moreover, electrodes of the samples were prepared by the hydrothermal method to investigate electrochemical properties. Cyclic voltammetry, galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy, and cyclic stability showed that the MnCo2O4/MWCNT/rGO composite with a high specific capacitance of 3346.6 F g−1 at the current density of 1 A g−1 had the highest capacitance and stability among all samples. The MnCo2O4/MWCNT/rGO electrode remained stable and preserved 91.18% of initial capacitance at the end of 10,000 cycles at the current density of 20 A g−1. This electrode, with a specific surface area of 45.9 m2 g−1 and suitable electrochemistry, has promise as an excellent electrode material for storing energy.