Proton and Electron Transport Impedance of Inactive Catalyst Layer Embedded in PEM Fuel Cell

Placing a catalyst layer between two membranes in a PEM fuel cell one gets a membrane-electrode assembly with inactive catalyst layer (ICL). A model for ICL impedance is developed taking into account finite electron conductivity of the layer. Analytical expression for the ICL impedance is derived. Analysis of characteristic features of the ICL Nyquist spectrum leads to simple analytical expressions for the high-frequency and polarization resistivity, for the summit frequency and for the straight high-frequency part of the spectrum. The results allow to estimate the ICL proton and electron conductivities and double layer capacitance without complicated curve fitting.