Author(s)

Punya A. Basnayaka, Manoj K. Ram, Lee Stefanakos, Ashok Kumar

Clean Energy Research Center, University of South Florida, Tampa, USA; Department of Electrical Engineering, University of South Florida, Tampa, USA.
Clean Energy Research Center, University of South Florida, Tampa, USA; Nanotechnology Research and Education Center, University of South Florida, Tampa, USA.
Department of Mechanical Engineering, University of South Florida, Tampa, USA; Clean Energy Research Center, University of South Florida, Tampa, USA.

Graphene-Polypyrrole (G/PPy) was synthesized by chemical oxidative polymerization method, and electrochemical impedance spectroscopy (EIS) analysis was employed to study the frequency response characteristics of supercapacitors based on G/PPy conducting polymer nanocomposite. It is found that a uniform G/PPy nanocomposite is formed with polypyrrole (PPy) being homogeneously surrounded by graphene nanosheets. The porous structure allowed electrolyte and ions diffusion in synthesized G/PPy nanocomposite. The metallic conductivity of Graphene-polypyrrole exhibited higher knee frequency at 125 Hz than the knee frequency of pristine PPy at 36 Hz. The high knee frequency of G/PPy supercapacitor is indicative of high power application and long cycle life. The G/PPy nanocomposite based supercapacitor with 1MH2SO4 as the electrolyte showed specific capacitances of 270 F/g at 0.1 Hz and112 F/g at 125 Hz.

Capacitance; Graphene; Conducting Polymers; Equivalent Circuit; Time Constant

P. A. Basnayaka, M. K. Ram, L. Stefanakos and A. Kumar, "Graphene/Polypyrrole Nanocomposite as Electrochemical Supercapacitor Electrode: Electrochemical Impedance Studies," Graphene, Vol. 2 No. 2, 2013, pp. 81-87. doi: 10.4236/graphene.2013.22012.