Capacitive behaviour of polypyrrole films prepared on stainless steel substrates by electropolymerization

Polypyrrole (PPy) films were deposited on stainless steel substrates by electropolymerization from pyrrole solutions containing 5-sulfosalicylic acid (SSA) as an anionic additive. The deposition yield was studied at galvanostatic and pulse deposition conditions. The films were investigated using scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The films prepared by pulse deposition method showed finer particle size, lower resistance and higher capacitance compared to the films deposited galvanostatically. The highest specific capacitance (SC) of 545Fg−1 was obtained at a scan rate of 2mVs−1. The films prepared by the pulse deposition method on stainless steel substrates are promising electrode materials for application in electrochemical supercapacitors (ES).