BIPOLAR PLATES, METHOD AND USE OF THESE PLATES IN POLYMER ELECTROLYTE MEMBRANE (PEM) FUEL CELLS OR OTHER ELECTROCHEMICAL CELLS

摘要

The present invention relates to a bipolar plate (BPP) with gas diffusion layer (GDL) for use in PEM fuel cells or other electrochemical cells. Parts of the bipolar plate are in direct contact with the gas diffusion layer, and parts of the bipolar plate are coated with a protective layer in areas where the bipolar plate is not in contact with the gas diffusion layer. The method of producing the combined BPP/GDL involves applying of a protective layer on the bipolar plate and subsequently hot-pressing of the gas diffusion layer onto the coated bipolar plate at elevated temperature and compaction pressure before and during curing of the protective layer. The coated bipolar plate and the gas diffusion layer are glued together, and direct contact between the GDL and the BPP is obtained. Another aspect of the invention is a bipolar plate prepared by applying a protective layer comprising an electrical conductive material on a conductive plate, and subjecting the coated plate to an elevated compaction pressure at elevated temperature before and during curing of the protective layer.