Pore network modelling was applied to simulate the oxygen transport behavior within these stochastically generated materials. The liquid water saturation was calculated using an invasion percolation algorithm. Three distinct scenarios were studied: varied MPL intrusion depth, varied MPL outer layer thickness, and constant MPL thickness with varied intrusion depth. In controlling the MPL intrusion, it was found that ~50-60 µm is the critical MPL thickness beyond which the saturated oxygen effective diffusion coefficient rapidly increases and the substrate saturation rapidly decreases (Figure 1). This study suggests that when the GDL is invaded by liquid water through cracks in the MPL, preferential MPL configurations exist for improving oxygen transport and minimizing substrate saturation. The results of this study can be used to guide the continued improvement of MPL fabrication.
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