Abstract: The contact resistance between bipolar plate (BPP) and gas diffusion layer (GDL) has a significant effect on the electric-chemical performance of the proton exchange membrane (PEM) fuel cell. The applied force on each of bolts in PEM fuel cell assembly is critical to the contact resistance between BPP and GDL for the PEM fuel cell. So the contact resistance between the BPP and the GDL is studied by using both experimental and finite element methods. The test results show that the contact resistance decreases with the increase of the clamping force quickly at first , and then gently. Based on the code ABAQUS, a coupled mechanical-electric procedure is developed. And then, the finite element method (FEM) is used to predict the contact resistance between the BPP and GDL under various clamping forces. The FEM results are in good agreement with the experimental results. In addition, the effect of the clamping force on the porosity of the GDL is analyzed by using FEM. The results indicate that the porosity decreases with the increase of the clamping force, especially at the round corner area of the BPP contacted with GDL.

Key words: Bipolar plate, Clamping force, Contact resistance, Gas diffusion layer, Porosity, Proton exchange membrane fuel cell