Synthesis and characterization of Mn2O3-Mn3O4 nanoparticles and activated charcoal based nanocomposite for supercapacitor electrode application

In the present article, manganese oxide (Mn2O3-Mn3O4) nanoparticles (NPs) have been synthesized at room temperature using co-precipitation method for the use as an electrode material by forming a composite with activated charcoal (AC) powder for its application in electrochemical supercapacitor. The synthesis temperature of 600 degrees C and 2 h of calcination time have been observed to be sufficient for the phase formation. The nanoparticles have been characterized by Synchrotron X-ray diffraction (SXRD), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The Mn2O3-Mn3O4 based nanocomposite (Mn2O3-Mn3O4-AC) has also been investigated by synchrotron radiation based X-ray photoelectron spectroscopy (XPES) to confirm the composite formation and to examine the electronic property of Mn2O3-Mn3O4 on composite formation. Supercapacitor cells (symmetrical) have been fabricated by making use of different composition of manganese oxide (Mn2O3-Mn3O4) nanoparticles-activated carbon (AC). Electrochemical properties of the prepared nanocomposite electrodes and fabricated supercapacitor cells have been characterized using a.c. impedance, cyclic voltammetry (CV) and charge discharge (CD) techniques by using 1 M H2SO4 and 6 M KOH as an the electrolytes. The optimized composition is 1:1 (mass ratio) of Mn2O3-Mn3O4 and activated charcoal and 600 degrees C for 2 h is an optimized temperature for synthesis of nanoparticles. The specific capacitance of the supercapacitor cells is stable up to 2000 cycles at 100 mV cm(-2), which show that the device has good electrochemical reversibility and cycle life with 1 M H2SO4 and 6 M KOH electrolyte.