Bipolar plate with titanium nitride coating

Abstract

According to a first aspect of the invention, a method for coating a bipolar plate is provided, comprising the steps of: - providing a bipolar plate wherein at least the outer layer of the bipolar plate comprises metallic titanium; - subjecting the bipolar plate to laser nitriding, thereby forming a titanium nitride coating on the outer surface of the bipolar plate. The inventors have found that laser nitriding of titanium bipolar plates results in bipolar plates comprising a highly stable TiN coating with good conformability, chemical stability, and / or high electrical conductivity. Furthermore, the application of a TiN coating by laser nitriding can be well integrated into the production of the bipolar plate, for example, in a roll-to-plate process involving laser welding, and is efficient and simple compared to deposition methods known in the art.The TiN coating on the bipolar plate can be used, for example, directly in an electrochemical reactor, or it can serve as a substrate for additional coatings.