Metallic separator for fuel cells and method of manufacturing the metallic separator

摘要

A metallic separator for fuel cells having a metal plate, an electroconductive coating layer covering at least a surface in front and back surfaces of the metal plate which contacts a raw material and/or a reaction product, and an electroconductive channel-forming member disposed on a surface of the coating layer and forming a channel for the raw material and/or the reaction product and/or a channel for a cooling medium for cooling. A surface layer on the metal plate has a tensile residual stress within such a range that no stress-corrosion cracking occurs.

主权项

1. A method of manufacturing a metallic separator for fuel cells, said method comprising, in the following order:
forming a channel for a raw material and/or a reaction product and/or a channel for a cooling medium for cooling by forming a corrosion-resistant coating layer having a matrix of a polymer resin in which a carbon-based conductive material is uniformly dispersed on at least one surface of front and back surfaces of an unpressed metal plate of austenitic stainless steel which contacts the raw material and/or the reaction product, and by thereafter disposing one or more electroconductive channel-forming members on a surface of the coating layer, wherein a surface layer of the metal plate has tensile residual stress within such a range that no stress-corrosion cracking occurs, wherein the electroconductive channel-forming members are formed directly on a surface of the coating layer opposite to a surface that contacts the metal plate, wherein the coating layer is formed by adhering a coating layer forming liquid, a coating layer forming powder or a coating layer forming sheet containing a carbon-based electroconductive material and a polymer resin to the surface of the metal plate by thermocompression including a hot press or a hot roller, and wherein a density of the coating layer is increased by the thermocompression.