Physical Modeling of Cathode Catalyst Layers in PEM Fuel Cells: The Role of Porous Structure and Water Accumulation
M. Eikerling (Simon Fraser University, Canada) and J. Liu (National Research Council, Canada)
My presentation focuses on cathode catalyst layers as the major competitive ground for transport and reaction in polymer electrolyte fuel cells. The overall objective of catalyst layer research is to maximize electrochemical rates at minimal catalyst loading. Our model accounts for the non-linear coupling of random porous morphology, liquid water accumulation, physico-chemical properties, and performance. This coupling triggers the transition between different wetting states and it can give rise to bistability in the transition region. Corresponding stability diagrams elucidate the effects of structural parameters and operating conditions on voltage efficiency, catalyst utilization, and water handling.