Topology optimization in modelling and design of the endplates of Proton Exchange Membrane Fuel cells

When individual proton exchange membrane fuel cells (PEMFCs) are assembled together to form a stack and provide energy for practical applications, an appropriate clamping load is usually required for better efficiency, high reliability, and excellent durability. Smaller clamping force increase ohmic resistance. In terms of the losses within proton exchange membrane fuel cells, the ohmic loss alone carries a significant portion. The ohmic loss occurs due to mainly the contact resistance between the GDL and the bipolar plate (BPP). On the other hand, excessive clamping force breaks the carbon fibers of the GDL results lifetime reduction and ultimately efficiency drop. That’s why the Endplates of the proton exchange membrane fuel cell (PEMFC) need to be well designed as their strength and rigidity directly affect the uniform clamping pressure distribution and thus affect the performance and lifetime of fuel cell stacks. This paper presents a methodology to design, analyze, and improve the mechanical responses of a practical proton exchange membrane fuel cell (PEMFC) stack. A practical assembly is analyzed with finite element analysis (FEA) to study the stress distribution and clamping pressure loss. To minimize the clamping pressure loss, the design criteria are proposed. And finally, topology optimization is carried out and the endplate is redesigned to obtain a lightweight optimized structural design.