Robust channel structures of proton exchange membrane fuel cells for uniform clamping pressure to gas diffusion layers

Proton exchange membrane fuel cells (PEMFCs) not only provide rapid dynamic response but also operate at low temperatures, which are desirable characteristics for transportation applications. However, metal bipolar plates in PEMFCs often deform under excessive clamping pressure, resulting in uneven pressure distribution. Rib-stiffened channels have been proposed to increase the structural stiffness of the bipolar plates, promoting durability. Parametric studies reveal that the supporting walls formed by the rib structure and a reduced top surface area contribute to better resistance against clamping force. Structural analysis and experimental assessments have confirmed the effectiveness of rib-stiffened channels in mitigating deformation. To ensure uniform compression of the gas diffusion layer during bolt assembly, a combined straight and rib-stiffened flow field has been designed and validated through structural simulations. Rib structures do not compromise fuel cell performance, as proved by computational fluid dynamics simulation with electrochemical reaction.