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A high performance supercapacitor based on graphene/polypyrrole/Cu2O-Cu(OH)2 ternary nanocomposite coated on nickel foam

Asen, P ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1021/acs.jpcc.7b00534
  3. Abstract:
  4. A simple and low-cost electrochemical deposition method is used to prepare reduced graphene oxide/polypyrrole/Cu2O-Cu(OH)2 (RGO/PPy/Cu2O-Cu(OH)2) ternary nanocomposites as the electrode material for supercapacitor application. First, graphene oxide-polypyrrole (GO/PPy) nanocomposite is electrochemically synthesized on Ni foam by electro-oxidation of pyrrole monomer in an aqueous solution containing GO and Tiron. Subsequently, the GO/PPy film is converted to the corresponding reduced form (RGO/PPy) by an effective and eco-friendly electrochemical reduction method. Then, a thin layer of Cu2O-Cu(OH)2 is formed on RGO/PPy film by chronoamperometry. The RGO/PPy/Cu2O-Cu(OH)2 nanocomposite is characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectra (FT-IR). SEM images show that Cu2O-Cu(OH)2 nanoparticles are dispersed on the surface of RGO/PPy film with an average particle size of 50-70 nm. The electrochemical performance of the as-prepared electrode is evaluated by various electrochemical methods using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) in 0.5 M Na2SO4 solution. In the three-electrode system, RGO/PPy/Cu2O-Cu(OH)2 exhibits an excellent gravimetric specific capacitance of 997 F g-1 at a current density of 10 A g-1, which is far better than GO/PPy (500 F g-1), RGO/PPy (685.5 F g-1), and GO/PPy/Cu2O-Cu(OH)2 (750F g-1). The utilization of the electrical double layer capacitance (EDLC) of graphene together with the pseudocapacitive behavior of PPy and Cu2O-Cu(OH)2 leads to a maximum energy density of 20 Wh kg-1 at power density of 8000 W kg-1 and a maximum power density of 19 1998.5 W kg-1 at an energy density of 5.8 Wh kg-1 for symmetric RGO/PPy/Cu2O-Cu(OH)2 supercapacitor. Furthermore, RGO/PPy/Cu2O-Cu(OH)2 nanocomposite maintains about 90% of the initial capacitance value after 2000 cycles. (Graph Presented). © 2017 American Chemical Society
  5. Keywords:
  6. Atomic force microscopy ; Capacitance ; Chronoamperometry ; Cyclic voltammetry ; Electric discharges ; Electrochemical electrodes ; Electrochemical impedance spectroscopy ; Electrodes ; Electrolytic reduction ; Electrooxidation ; Foams ; Graphene ; Nanocomposites ; Nickel ; Particle size ; Polypyrroles ; Reduction ; Scanning electron microscopy ; Solutions ; Spectroscopy ; Supercapacitor ; X ray diffraction ; Electrical double-layer capacitances ; Electrochemical deposition methods ; Electrochemical performance ; Electrochemical reductions ; Energy dispersive X-ray spectrometry ; Fourier transform infrared spectra ; Galvanostatic charge discharges ; Supercapacitor application ; Copper
  7. Source: Journal of Physical Chemistry C ; Volume 121, Issue 12 , 2017 , Pages 6508-6519 ; 19327447 (ISSN)
  8. URL: https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b00534