Abstract: A three-dimensional multi-flow channel proton exchange membrane fuel cell (PEMFC) model has been developed to investigate the deformation of gas diffusion layer (GDL) with different assembly force and different contact ratio of channel. The results indicate that the GDL under the land part changes significantly while the central region under the flow channel almost has no deformation with increasing assembly force. When the contact ratio of channel is not 100%, the deformation of GDL is not symmetrical due to the shear stress, and the thickness of GDL under the flow channel even exceeds its initial thickness, which produces the phenomenon of “embossment” in the flow channel. And with the increasing of assembly force, this phenomenon is more obviously. Finally, the porous structure of gas diffusion layer changes and thus the transport parameters such as porosity and permeability begin to change, which will bring new problems for water and thermal management of PEMFC.

Key words: proton exchange membrane fuel cell, gas diffusion layer, assembly force, contact ratio of flow channel