1. Example: Simulation of Electrochemical Impedance Spectroscopy

2. Introduction
This model treats a 1D investigation of a fuel cell cathode using Electrochemical Impedance Spectroscopy, or AC impedance.
The effect of frequency and electrolyte conductivity is investigated.
Firstly, the stationary problem is solved, and then for the frequency sweep, using the parametric solver.

3. Geometry

4. Domain equations, anode
Electronic balance
Ionic balance

5. Domain equations, cathode
Electronic balance
Ionic balance

6. Boundary conditions, anode
at current feeder-
anode interface
at electrolyte-
anode interface
Boundary conditions, cathode
at current collector-
cathode interface
at electrolyte-
cathode interface

7. Domain equations, free electrolyte
Boundary conditions, free electrolyte
at electrolyte-
anode interface
at electrolyte-
cathode interface

8. Nyquist Plot

9. Nyquist plot with changed conditions

10. Concluding remarks
You have to firstly solve the stationary problem and then solve as many frequency sweeps as you like using the parametric solver.
The fact that complex numbers can be entered into COMSOL Multiphysics makes this type of modeling unique to the FEA world.