A high performance PEDOT/PPy composite electrode enabled by regulating molecular growing orientation

The conductive polymer is a promising candidate for energy storage devices due to its flexibility, light weight, and low cost. Polypyrrole (PPy) has been widely investigated as active material in supercapacitors. Here, conductive Poly (3,4-ethyldioxythiophene) (PEDOT) is used as a substrate for electropolymerization of PPy. The counterion CF3SO3- of PEDOT can adjust the electropolymerization rate and molecular growing orientation of PPy. Therefore, the mass capacitance of the composite electrode (PEDOT/PPy) reaches a top value of 551 F/g, at 2 A/g in 1 M H2SO4 electrolyte. This value outperforms the PPy electrode on the ITO substrate by around 53.9%. Moreover, the composite electrode (PEDOT/PPy) shows better stability compared to the PPy on the ITO substrate. This study provides a new route for the preparation of high electrochemical performance conductive polymer composite electrodes.