Fuel cell limiting the phenomenon of corrosion

摘要

A fuel cell stack includes first and second membrane electrode assemblies and a metal bipolar plate interposed between the first and second membrane electrode assemblies. The bipolar plate comprises first and second metal sheets facing the first and second membrane electrode assemblies and is securely fastened by welds. There is a gas diffusion layer interposed and compressed between the first membrane electrode assembly and the bipolar plate. In the absence of compression on the gas diffusion layer, regions of the gas diffusion layer surrounding the welds have a thickness smaller by at least 5 μm relative to the average thickness of the gas diffusion layer. This is done so that the contact pressure of the gas diffusion layer with the bipolar plate in the area of the welds is lower than its average contact pressure with the bipolar plate.

主权项

1. A fuel cell stack, comprising:
first and second membrane electrode assemblies; a metal bipolar plate interposed between the first and second membrane electrode assemblies, this bipolar plate comprising first and second metal sheets facing the first and second membrane electrode assemblies and securely fastened by welds; and a gas diffusion layer interposed and compressed between the first membrane electrode assembly and the bipolar plate;wherein prior to being compressed, regions of the gas diffusion layer surrounding the welds have a thickness smaller by at least 5 μm relative to the average thickness of the gas diffusion layer prior to being compressed, so that after compression of the gas diffusion layer the contact pressure of the gas diffusion layer with the bipolar plate in the area of the welds is lower than its average contact pressure with the bipolar plate.