A macrohomogeneous model is presented for a porous electrode that includes coupled potential and concentration gradients with linear kinetics. The equations are solved to obtain an analytical expression for the impedance of a porous electrode. Complex plane plots are presented that illustrate two well-defined arcs: a kinetic arc and a diffusion arc with their time constants far apart. The effects of parameters such as exchange current density, porosity, diffusion coefficient, thickness, and interfacial area on the impedance spectra are presented. The usefulness of the analytical solution in investigating the effect of solution phase diffusion is also presented.
Published in Journal of the Electrochemical Society, Volume 151, Issue 6, 2004, pages A905-A913.
© The Electrochemical Society, Inc. 2004. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in
Devan, S., Subramanian, V.R., & White, R.E. (2004). Analytical Solution for the Impedance of a Porous Electrode. Journal of the Electrochemical Society, 151(6): A905-A913.
Publisher’s Version: http://dx.doi.org/10.1149/1.1739218