Polymer Electrolyte Membrane Fuel Cells (PEMFCs) recently received a relevant interest as an electric power generation technology in Fuel Cells Electric Vehicles (FCEVs) to decarbonize hard-to-abate sectors as a complement to Battery Electric Vehicles (BEVs). However, the massive requirements of power and durability indicate the urgent need to develop higher-than-ever power density designs with minimum internal gradients to mitigate degradation, discarding sub-optimal designs since the early design stage.
Starting from the outcomes of a first study, confirming that for industry-relevant PEMFCs the parallel channel flow field was the only archetype able to minimize jointly pressure losses and limiting super-saturation at high current density, still several degrees of freedom exist for the cell designer. In this study, the research of the optimal PEMFC design is fine-tuned using a CAE-guided design process. Candidate solutions are explored using an optimization software and solving for the coupled mass/heat/charges transport processes in PEMFCs. The study aims at identifying the designs maximizing the current density and/or the membrane water content. The investigated input variables are the width of the bipolar plate ribs and the thickness of the gas diffusion layers, evaluated independently at cathodic and anodic side. The methodology shown in this paper leverages the versatility of parametrized 3D-CAD models and of multi-dimensional 3D-CFD simulation and it is applied to an elementary cell unit, albeit being easily scalable to more complex geometries. Starting from a conventional baseline design, two optimized configurations are identified that maximize the current density under the same voltage (+10%) and the uniformity of the membrane water content (+13%), respectively, showing the entity of performance gain made possible by the wise use of optimization methods in the field of PEMFC engineering.