Kinetic parameters diffusion coefficient, double-layer

As expected, the impedance responses obtained in practice do not fully match that of the model of Fig. 9.13. However, as shown by the typical case of Fig. 9.14 which illustrates the response obtained for a 5 mol% ClO -doped polypyrrole electrode in contact with a LiC104-propylene carbonate solution (Panero et al, 1989), the trend is still reasonably close enough to the idealised one to allow (possibly with the help of fitting programmes) the determination of the relevant kinetics parameters, such as the charge transfer resistance, the double-layer capacitance and the diffusion coefficient. 

Conducting polymers have been studied using the whole arsenal of methods available to chemists and physieists. Eleetrochemical teelmiques, mostly transient methods such as cychc voltarmnetiy (CV), chronoamperometry (CA) and chronocoulom-etry (CC), are the primary tools used to follow the formation and deposition of polymers, as well as the kineties of their charge transport processes. Electrochemical impedance speetroseopy (EIS) has become the most powerful technique used to obtain kinetic parameters sueh as the rate of charge transfer, diffusion coefficients (and their dependenee on potential), the double layer capacity, the pseudocapacitance of the polymer film, and the resistance of the film... 

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