Synthesis and Characterization of Supercapacitor Electrodes Based on Graphene and MnO2 Nanostructure

Mardi, Saeed | 2013

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45442 (04)
  4. University: Sharif University of Technology
  5. Department: Physics
  6. Advisor(s): Moshfegh, Alireza; Moradlou, Omran
  7. Abstract:
  8. Supercapacitors represent a new class of energy storage devices that have been attracted many researchers in last few years. Graphene with unique properties such as superior electrical conductivity and large specific surface area is one of the most suitable materials in supercapacitor applications. Besides, metal oxides are being used as active compounds in supercapacitors due to their role in redox reactions. In this research, synthesis and characterization of supercapacitor electrodes based on graphene and MnO2 nanostructured materials was studied under different conditions. For this purpose, Graphene oxide (GO) was synthesized by Hummers’ method and then, it was deposited on a nickel foam via electrophoretic process with applied potential of 2 V in solution containing MgSO4 and GO . Finally, MnO2 anodically electrodeposited on reduced GO/Ni-foam by using successive cyclic voltammetry (CV) at the scan rate of 0.1 Vs-1 in 5 cycles. Morphology and chemical composition of the prepared electrode were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrochemical and capacitive properties of the synthesized supercapacitor electrodes were studied in a three-electrodes system using various techniques including CV in the potential window of -0.2 to 0.8 V ,charge-discharge (CD) at a constant current , and the electrochemical impedance spectroscopy (EIS), all in 1.0 M Na2SO4 solution. The results showed that the synthesized MnO2/RGO supercapacitor electrode exhibited a capacitance of 226.5F/g
  9. Keywords:
  10. Supercapacitor ; Graphene ; Specific Capacitance ; Cyclic Voltammetry ; Electrochemical Impedance Spectroscopy ; Galvanostatic Discharge ; Manganese Oxide

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