Simulation of Electrochemical Impedance Spectroscopy
Model ID: 218
A fuel cell unit cell is modeled using the full Butler-Volmer expression for the anodic and cathodic charge transfer reactions. The anodic and cathodic overpotentials depend on the local ionic and electronic potentials, which are obtained from the charge balance equations for ionic and electronic current. A small sinusoidal perturbation of the potential around a given cell voltage is applied and the frequency of this perturbation is varied from fractions of a Hertz to several hundred thousands Hertz. The phase shift at the different frequencies is studied.
|Nyquist plot of the cathode impedance from the one-dimensional model at a lowered effective electronic conductivity of the cathode.|