Metallic flow field plates, also called bipolar plates, are an important component of fuel cell stacks, electrolyzers, hydrogen purification and compression stacks. The manufacturing of these plates by means of stamping or hydroforming is highly suitable for mass production. In this work, a toolbox is created that is suitable for a screening process of different flow field design variants. For this purpose, the geometry and computational mesh are generated in an automated manner. Basic building blocks are combined using the open source software SALOME, and these allow for the construction of a large variant of serpentine-like flow field structures. These geometric variants are evaluated through computational fluid dynamics (CFD) simulations with the open source software OpenFOAM. The overall procedure allows for the screening of more than 100 variants within one week using a standard desktop computer. The performance of the flow fields is evaluated on the basis of two parameters: the overall pressure difference across the plate and the relative difference of the hydrogen concentration at the outlet of the channels. The results of such a screening first provide information about optimum channel geometry and the best choice of the general flow field layout. Such results are important at the beginning of the design process, as the channel geometry has an influence on the selection of the metal for deep drawing or hydroforming processes.

Formed and welded metal PEM fuel cell bipolar plates are the most prominent strategy to reach low cost and high performance in a high-volume production environment. Using the proprietary coilbased Hydrogate process, Borit is able to achieve world class thin sheet metal forming with excellent repeatability and reproducibility. An overview of the typical process flow for metal bipolar plate production, process capabilities and yields will be shown. Implementing the appropriate process controls overcomes the challenges related to laser welding of thin metal foils with constraints regarding plate flatness, leak tightness and weld strength. An update on the latest developments will be presented, together with the related QC and traceability efforts.