Capacitive behaviour of polypyrrole, prepared by electrochemical and chemical methods

Polypyrrole (PPy) electrodes for electrochemical supercapacitors were prepared by galvanostatic electropolymerization, pulse electropolymerization and chemical polymerization methods using pyrocatecholsulfonphthalein as an anionic dopant. Pulse electropolymerization provided improved impregnation of Ni plaque current collectors and formation of nanostructured coatings on Ni particles. The electrodes prepared by pulse electropolymerization showed higher porosity, improved PPy contact with current collectors, higher capacitance, lower electrical resistance, improved capacitance retention at high charge–discharge rates and improved cycling stability. The use of Ni plaque current collectors allowed good electrochemical performance at high PPy mass loading. The highest capacitance of 320Fg−1 was achieved at a scan rate of 2mVs−1.