An AC‐Impedance Study of Electrochemical Processes at Nafion‐Coated Electrodes

Publisher Website
Google Scholar
Abstract
The system was investigated by the ac‐impedance method, covering both the semi‐infinite and the finite (very low frequency) diffusion regimes. Upon decreasing the modulation frequency, a transition from semi‐infinite diffusion to finite diffusion is observed, with different apparent diffusion coefficients calculated for the two limiting cases. The results can be accounted for by a distribution of diffusion coefficients in the film and are quantitatively consistent with a model that assumes two parallel diffusion paths in the film. The values obtained by curve‐fitting to experimental results are , and , with comparable concentrations of reactive ions in the two forms. The two parallel paths are attributed to different domains of the polymer.

This publication has 0 references indexed in Scilit: