Relating Anode Gaps to the Positioning of the Reference Electrode in PEM Fuel Cells

We present analytical solutions for the potential and current density distributions in the vicinity of inactive (“dead”) regions inside a PEM fuel cell anode. For simplicity, the dead region is modeled as a step function for the anode exchange current density, representing membrane gaps or delamination. The solutions exhibit a large peak of the anode current density just outside the dead region. This overshoot can substantially exceed the average current density, thereby accelerating membrane degradation. In the limit of large gap sizes, we demonstrate how these findings relate to the positioning of a reference electrode which can independently measure the anode and cathode overpotential, respectively.   

[1] A. A. Kulikovsky and P. Berg, Analytical description of a dead spot in a PEM fuel cell anode, ECS Electrochem. Lett., 2, pp. F64-F67 (2013)

[2] P. Berg and A. A. Kulikovsky, A model for a crack or a delaminated region in a PEM fuel cell anode: Analytical solutions, Electrochim. Acta, submitted.