Journal of Engineering Research and Reports

Bipolar plates are pivotal components in proton exchange membrane fuel cells (PEMFCs), performing current collection, reactant distribution, heat management, and stack structural support. Their material choice and ma nufacturing route strongly influence cell efficiency, durability, and cost. Traditional stamping of metallic plat es has dominated high-volume production due to speed and low unit cost but struggles with complex microch annel geometries, springback, and surface integrity. Emerging techniques—hydroforming, incremental and ho t forming, and additive manufacturing—promise improved geometric freedom, reduced tooling needs, and int egration of functions, yet each introduces trade-offs in material thinning, electrical and corrosion performanc e, cycle time, and scalability. Coating and surface treatments further complicate process chains but are essenti al to meet conductivity and corrosion resistance targets. As PEMFCs transition from niche applications to aut omotive and stationary power markets, optimizing forming methods to balance manufacturability, performance, and lifecycle cost is critical. This study situates comparative analysis of forming methods within that imper ative, aiming to guide material-process selections that advance commercial viability and long-term durability of PEMFC bipolar plates.

Proton Exchange Membrane Fuel Cells (PEMFCs) rely critically on the performance and manufacturability of bipolar plates, which serve multiple functions including current collection, gas distribution, thermal manage ment, and mechanical support. Each method is examined through the lenses of formability, dimensional acc uracy, surface quality, mechanical robustness, electrical conductivity, corrosion resistance, and production cos t. Stamping remains the industrial benchmark due to its high throughput and established toolsets; however, it f aces limitations in achieving complex three-dimensional flow field geometries without compromising precisio n or inducing springback. Hydroforming offers superior capability for producing intricate, smooth internal channels and reducing tooling complexity for certain geometries, but it introduces challenges in process control, material thinning, and cycle time that affect scalability. Additive manufacturing enables unprecedented geometric freedom and rapid design iteration, facilitating integrated features and lightweighting, yet it presently encounters hurdles in achieving the electrical and surface properties required for long-term PEMFC operation and in meeting mass-production speed and cost targets. Hybrid strategies—combining forming, machining, and surface-treatment steps—emerge as promising compromises that leverage the strengths of each approach to tailor bipolar plates for specific application regimes, from automotive-scale high-volume production to bespoke research devices.

The comparative assessment integrates technical performance metrics with economic and environmental considerations, highlighting trade-offs between manufacturing complexity, material utilization, and lifecycle impacts. Critical factors such as material selection (graphite, coated metals, composite materials), coating strategies to mitigate corrosion and contact resistance, and post-processing treatments (e.g., plating, heat treatment, machining) are woven into the evaluation of forming routes. The analysis identifies gaps in current knowledge—most notably the need for standardized test protocols to evaluate formed plate performance under realistic operating conditions, and further development of surface treatments compatible with additive and hydroformed substrates.