A Model for the Concentration Admittance of a Polymer Electrolyte Fuel Cell

Abstract

A dynamic model for the concentration admittance of a polymer electrolyte fuel cell is presented. The model takes into account oxygen transport in the cathode channel, the gas diffusion layer, and the cathode catalyst layer. An analytical solution for the concentration admittance is derived. We observe that the admittance at the air channel outlet is not affected by faradaic reactions, and it contains information on the oxygen transport coefficients in the cell. The admittance measured at the air channel outlet can be fitted using the formula obtained in this work to extract the oxygen transport coefficients. Practical methods for measuring the concentration admittance are proposed.