Metal bipolar plate for proton exchange membrane fuel cell and preparation method thereof

The invention discloses a metal bipolar plate for a proton exchange membrane fuel cell. A modifying layer is arranged on the surface of the metal bipolar plate and comprises a metallic titanium intermediate layer contiguous to a metal substrate and a carbon-based film composite layer on the metallic titanium intermediate layer. The carbon-based film composite layer on the metallic titanium intermediate layer is a carbon-based film composite layer which is formed by mixing carbon, titanium carbide and metallic titanium. The invention has the advantages that a metal bipolar plate matrix is provided with multilayer protection; protective layers can be mutually compensated, so that the bipolar plate has extremely-strong corrosion resistant performance and thereby remarkably prolongs the service life of the bipolar plate; meanwhile, the bipolar plate has excellent conductive performance, can remarkably reduce the internal resistance of the proton exchange membrane fuel cell and improve the output performance of the cell; and the modifying layer has low cost, which is beneficial to reduce the cost of the whole fuel cell system, thereby improving the overall competitiveness.