Browsing by Author "Peninah Nzangi"

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    Ternary Composite Materials Based on Manganese Dioxide Doped Reduced Graphene Oxide and Conducting Polymer Electrode Material for Supercapacitors
    (Addis Ababa University, 2024-03) Peninah Nzangi; Girum Ayalneh
    Ideal energy storage devices should have both high energy and power density. Electrodes having high specific surface area and thinner dielectrics are used in supercapacitors. Because of these characteristics, they have power and energy densities that are higher than those of batteries and traditional capacitors, respectively. In this work, a ternary composite comprising reduced graphene oxide, Manganese dioxide, and poly-2,5-dimethylaniline (rGO/MnO2/PDMA) was synthesized via in-situ polymerization. To investigate the effect of manganese dioxide on the composite material, different ratios of MnO2 (80%,60%, and 30%) were synthesized. The characterization techniques employed are Fourier-Transform Infrared (FTIR), X-ray Diffraction (XRD), Brunner Emmet Teller (BET), and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Cyclic Voltammetry (CV), Galvanostatic Charge/Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS) techniques in 1MNa2SO4. A maximum specific capacitance of 176.4F/g for rGO/MnO2/PDMA in a three-electrode system was attained at a current density of 0.0016A/cm^2. 80%MnO2 had the best electrochemical performance and the performance dwindled as the ratio of MnO2 decreased. Asymmetric electrodes performed better than symmetric electrodes in a two-electrode system with maximum specific capacitance values registered at 0.0016A/cm^2 current density for ternary composites as 86 F/g respectively. The ternary composite performed better than the binary composite and the conducting polymer. Despite excellent performance by rGO, it is very expensive and therefore uneconomical for commercial applications. This opens possible research opportunities that aim to use it in small quantities to increase the conductivity and specific capacitance of other cheaper materials, to lower production cost.