Synthesis of polypyrrole film by pulse galvanostatic method and its application as supercapacitor electrode materials

Polypyrrole (PPy) film-coated stainless steel electrodes were prepared from aqueous solution containing 0.5 M p-toluene sulphonic acid and 0.1 M pyrrole using pulse galvanostatic method (PGM) and galvanostatic method (GM). The morphology was characterized by scanning electron microscopy. The electrochemical properties of PPy films were investigated with cyclic voltammetry, charge-discharge tests, and ac impedance spectroscopy. The results showed that the PGM-PPy films exhibited higher specific capacitance, better high-rate discharge ability and lower resistance, and were more promising for applications in supercapacitor than GM-PPy films. The specific capacitance (SC) of PGM-PPy films was 403 F g(-1) in 1 M H2SO4 electrolyte and 281 F g(-1) in 1 M NaNO3 electrolyte.