Polarization curve of a PEM fuel cell with poor oxygen or proton transport in the cathode catalyst layer

Simple analytical expressions for the polarization voltage of the cathode side of a PEM fuel cell for the cases of poor oxygen or proton transport in the cathode catalyst layer (CCL) are derived. In addition, the shapes of local current density and oxygen concentration along the channel are obtained. All the expressions take into account finite oxygen stoichiometry of the oxygen flow. The results can be used for in-situ analysis of the nature of transport problems in the catalyst layer.

► We study the effect of oxygen stoich λ on the cathode overpotential η in PEMFC. ► For the cases of poor oxygen or proton transport in the cathode catalyst layer. ► Exact expressions for η are derived. ► The functions η(j,λ) are different in the proton- and oxygen-limiting regimes.