Cyclic voltammetric studies of the relaxation processes during the oxidation of poly(3,4-ethylenedioxythiophene) in propylene carbonate solution

The redox switching of poly(3,4-ethylenedioxythiophene) (PEDOT) electrodeposited on a platinum electrode surface was analysed during cyclic voltammetry experiments in propylene carbonate solution. The effects of the holding potential Ew, and the waiting time tw were studied during the oxidation. For a fixed value of Ew, an increase of the anodic peak current and the peak potential as a function of tw was observed. On the other hand, for a fixed value of tw, a linear relationship between the anodic peak potential and Ew was found. In order to quantify the electro-mechanical stress during the waiting time, an anodic over-tension in relation to the conformational relaxation was determined. Finally, a dimensionless parameter was introduced to characterize the interdependence of the anodic peak current and the plateau current.