Synthesis and Characterization of Manganese (IV) and Cobalt (II/III) Oxides Based on Graphene for Supercapacitors Application

Abstract

As an ideal electrochemical energy storage candidate, supercapacitors have gained increasing attention due to high power density, long cycle life and fast charge/discharge rate, which is more suitable for large power components. Conventional lithium-ion batteries are widely used in portable electronic equipment such as laptop computers, cell phones and electric vehicles. In this study, the graphene supported manganese (IV) oxide (MnO2/GR), cobalt (II/III) oxide (Co3O4/GR) and manganese-cobalt oxide (MnO2-Co3O4/GR) nanocomposites were synthesized using the microwave irradiation method. The synthesized composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical performance of the graphene supported MnO2, Co3O4 and MnO2-Co3O4 nanocomposites was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge. The graphene supported MnO2-Co3O4 nanocomposites have significant influence on the electrochemical performance as compared with that of the MnO2/GR and Co3O4/GR. The maximum specific capacitance of 152 F g-1 was achieved at the MnO2-Co3O4/GR in the 1 M Na2SO4 aqueous solution at the scan rate of 10 mV s-1. Acknowledgement This research is funded by the European Social Fund under the No. 09.3.3-LMT-K-712-02-0142 “Development of Competences of Scientists, other Researchers and Students through Practical Research Activities” measure.