Synthesis and characterizations of MnO2/CNT nanocomposite for usage as electrodes in high-performance supercapacitor

Abstract

Taking into account the unique characteristics of MnO₂ (manganese oxide) nanoparticles and their exceptional physicochemical properties, which make them useful in energy storage devices like supercapacitors, this article has focused the synthesis and characterizations of MWCNT/MnO₂ nanocomposites with different wt. % of MWCNTs. In the present article, the hydrothermal method was used to create MWCNT/MnO₂ nanocomposites. The information regarding structure, Raman bands, functional groups, optical bandgap, and surface characteristics was obtained using an XRD tool, a Raman spectrometer, an FTIR spectrometer, a UV–Vis-NIR spectrometer, and a FE-SEM with EDX, in that order. Moreover, the electrochemical characteristics have been examined using galvanic charge-discharge (GCD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Using XRD, the structural characteristics were retrieved and rejected the possibility of any secondary phases with the determined crystallite size of 22 nm for 1wt.% MWCNT/MnO₂ nanocomposite. Additionally, the material underwent Raman tests indicating all the vibrational modes of MWCNT/MnO₂ nanocomposite including -COOH, -OH, -C-O, -C=C and Mn-O respectively. From CV, the specific capacitance was found highest for 1wt.% MWCNT/MnO₂ nanocomposite ∼729.8F/g at 5mV/s scan rate and from GCD graph it was ∼ 405.5 F/g. EIS spectra confirmed R_s and R_ct values for 1wt.% MWCNT/MnO₂ nanocomposite ∼ 5.57Ω and 15.60Ω, respectively. Thus, keeping in view the above results, the MnO₂/CNT nanocomposites can be utilized as an anode material for energy storage applications.