Nanocomposite of (α-Mn3O4/MnO)@rGO as a high performance electrode material for supercapacitors

It is demonstrated for the first time, strongly coupled reduced graphene oxide with alpha-Mn3O4/MnO nanocomposite acts as an electrode material for supercapacitors. The material has displayed an optimum specific energy of 21 and 10.8 Wh/kg, and a power density of 206 and 3979 W/kg at the constant current values of 1 and 20 mA respectively. Furthermore, capacity retention of similar to 92.7 % was observed after 3000 cycles at a scan rate of 100 mV/s. This material was synthesized via a single step sol-gel route and subsequently calcined at 700 degrees C in an inert atmosphere (N-2). The obtained (alpha-Mn3O4/MnO)@rGO nanomaterial was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscope (HR-TEM), scanning tunneling electron microscope-energy dispersive x-ray spectroscopy (STEM-EDS) to investigate the phase and structural morphology. Furthermore, electrochemical studies such as cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy for the nanocomposite were performed with three electrode systems in an aqueous electrolyte of 1 M KOH. (C) 2021 Elsevier Ltd. All rights reserved.