Bipolar plates in a fuel cell membrane: the effect on the design performance and metallic material adapted to search

This work is a contribution to the study of the role of bipolar plates on the operation of fuel cell membrane, in particular the effect of the design of these plates as a distributor of reactive gases, and the search for metallic materials that can replace conventional carbon materials. The performance of fuel cells are limited by, among other problems related to thermal hydraulics: dewatering membranes and waterlogging distribution channels gas. This performance is also limited by the type of membrane and bipolar plates used. This thesis deal primarily a comparison between membranes and bipolar plates. We also investigated problems related to moisture, especially the water flooding in the channels of a fuel cell by visualization tests: the evacuation of liquid water is highly dependent on the etching plates In addition, we have searched for metallic materials candidates embodiment to replace the bipolar plates of graphite, cumbersome and costly. Two materials have been studied: 316L stainless steel and the nickel - tungsten deposited on a copper plate. The 316 L stainless steel, used as material for bipolar plates, shows good resistance to aggressive conditions within the fuel cell membrane, as shown by tests carried out over nearly 1000 hours. (author)