Semi-Analytical Methodology to Correct Polarization Curve to Measure Tafel Slope for an Electronic Resistance Laden Catalyst Layer

The polarization curve of a fuel cell shows the relationship between operating current and cell voltage. The cell voltage is lower than the equilibrium voltage due to several losses within the system. For a proton exchange membrane fuel cell (PEMFC), such losses typically arise from proton transport losses in the membrane, transport and kinetic losses in the catalyst layers, electronic transport losses in the cell components like flow-fields and the gas diffusion layers, and mass transport losses. For a mass-transport-free PEMFC operation, a previously established method corrects the polarization curve to obtain the Tafel slope of the oxygen reduction reaction for a catalyst layer without electronic transport resistance (e.g., Pt/C catalyst layer). This work builds upon that approach, extending the Tafel slope estimation to systems where both protonic and electronic transport resistances of the cathode catalyst layer are significant (e.g., platinum-group-metal-free catalysts).