Metallic separator for fuel cells and method of manufacturing the metallic separator
AssigneeUniversity of Yamanashi
InventorsMasahiro Watanabe, Hiroyuki Uchida, Hisao Yamashita, Kenji Miyatake
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Abstract
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.
Claims13
A metallic separator for fuel cells comprising:
- 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, containing one or more porous carbon-based electroconductive materials selected from the group consisting of carbon particle sintered materials, carbon fiber sintered materials, carbon fiber woven fabrics, and carbon fiber nonwoven fabrics, and forming a channel for the raw material and/or the reaction product and/or a channel for a cooling medium for cooling, wherein the channel is formed by combining one or more of channel-forming members having a porosity of 50% or more, channel-forming members having a porosity of 10 to 50%, and channel-forming members having a porosity of 10% or less, and wherein a surface layer on the metal plate has a tensile residual stress within such a range that no stress-corrosion cracking occurs,
- wherein the electroconductive coating layer includes a thermocompressed polymer resin, and
- an amount of the polymer resin in the electroconductive coating layer is in a range from 40 to 60 mass %.
A method of manufacturing a metallic separator for fuel cells comprising:
- forming an electroconductive coating layer at least on a surface in front and back surfaces of the metal plate which contacts a raw material and/or a reaction product;
- and
- joining to a surface of the coating layer an electroconductive channel-forming member containing one or more porous carbon-based electroconductive materials selected from the group consisting of carbon particle sintered materials, carbon fiber sintered materials, carbon fiber woven fabrics, and carbon fiber nonwoven fabrics, and forming a channel for the raw material and/or the reaction product and/or a channel for a cooling medium for cooling, wherein the channel is formed by combining one or more of channel-forming members having a porosity of 50% or more, channel-forming members having a porosity of 10 to 50%, and channel-forming members having a porosity of 10% or less, and wherein a surface layer on the metal plate has a tensile residual stress within such a range that no stress-corrosion cracking occurs,
- 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,
- wherein a density of the coating layer is increased by the thermocompression.
Dependencies are inferred from the claim text.