Synthesis of PEDOT: PPy/AC composite as an electrode for supercapacitor

Abstract

The electrochemical deposition of composite poly(3,4-ethylenedioxythiophene) (PEDOT):polypyrrole (PPy)/activated carbon (AC) film is fabricated in a solution composed of 10 mM concentrations of each monomer (3, 4-Ethylenedioxythiophene (EDOT) and Pyrrole (Py) in (1:1)) and 0.1 M lithium perchlorate (LiClO4) aqueous solution as a supporting electrolyte at a potential 1.1 V which is found by obtaining Linear Sweep Voltammetry intercept point of the two monomers. AC particles (50 gL−1) are dispersed in this solution. The prepared composite films are analyzed by the scanning electron microscope (SEM) for surface morphology and polymer functional groups are analyzed by the Fourier transform infrared (FTIR) analysis. The SEM results have shown that PEDOT:PPy/AC composite film is porous structure which proved the deposition of AC and also, BET analysis was performed for surface area and pore size measurement. The FTIR spectra confirmed the functional group of conductive polymers (PEDOT and PPy) present in the composite film deposited on ITO (1 cm2) glass. The electrochemical measurements of the prepared samples are evaluated by using galvanostatic charge/discharge (GCD) and cyclic voltammetry in 2 M KCl aqueous solution in three electrodes set up. Also, electrochemical impedance spectroscopy is analyzed by using 5 mM aqueous solution of K3[Fe (CN)6] including 0.1 M KCl (supporting electrolyte) aqueous solution within three-electrode cell system. The value of specific capacitance of synthesized composite is evaluated from GCD and its value found to be 622 Fg−1 by applying current density value of 1 Acm−2. Moreover, energy density value along with power density value of the composite PEDOT: PPy/AC are calculated and found to be 47 Whkg−1 and 2223 Wkg−1, respectively. It has also been analyzed that this composite retained 87.5% cyclic stability. So, all of the above mentioned analysis reflect that PEDOT:PPy/AC composite is a potential electrode material employed in supercapacitors. It is worth mentioning that PEDOT:PPy/AC composite electrode has improved the storage capacity of the prepared device.