Method for producing fuel cell separator, and separator material

Patent metadata

Field	Value
Publication number	US-2019190036-A1
Application number	US-201816211357-A
Country	US
Kind code	A1
Filing date	Dec 6, 2018
Priority date	Dec 20, 2017
Publication date	Jun 20, 2019
Grant date	—

Abstract

Provided are a method for producing a fuel cell separator, and a separator material that can prevent carbon in a carbon layer formed on the surface of a metal substrate from being detached during press forming, and thus can suppress failures in the press forming. The method is a method for producing a fuel cell separator having formed thereon gas flow channels through which fuel gas or oxidant gas to be supplied to a fuel cell stack flows, the method including preparing a plate-shaped separator material including a titanium substrate, a carbon layer covering the titanium substrate, and a resin layer covering the carbon layer; press-forming the prepared separator material into the shape of the separator such that the separator has the gas flow channels formed thereon; and removing the resin layer from the press-formed separator.

First claim

What is claimed is:

1 . A method for producing a fuel cell separator, the fuel cell separator having formed thereon a gas flow channel through which one of fuel gas or oxidant gas to be supplied to a fuel cell flows, the method comprising:
preparing a plate-shaped separator material including a metal substrate, a carbon layer covering the metal substrate, and a resin layer covering the carbon layer; press-forming the prepared separator material into a shape of the separator such that the separator has the gas flow channel formed thereon; and removing the resin layer from the press-formed separator.

2 . The method for producing the fuel cell separator according to claim 1 ,
wherein the preparing includes
preparing as the metal substrate a titanium substrate containing one of titanium or titanium alloy, and applying carbon black to the titanium substrate, thereby forming a carbon black layer, and
performing heat treatment on the titanium substrate having the carbon black layer formed thereon, thereby diffusing titanium atoms from a surface of the titanium substrate into the carbon black layer, and thus forming a mixture layer as a part of the carbon layer on the surface of the titanium substrate, the mixture layer containing the carbon black of the carbon black layer and titanium oxide holding the carbon black.

3 . The method for producing the fuel cell separator according to claim 1 ,
wherein the preparing includes applying a suspension to a surface of the carbon layer, the suspension being obtained by dispersing in a liquid medium resin particles of thermoplastic resin as a base material of the resin layer, and heating the resin particles to a temperature of greater than or equal to a softening point of the resin particles and drying the liquid medium, thereby forming the resin layer on the surface of the carbon layer.

4 . The method for producing the fuel cell separator according to claim 3 ,
wherein: the resin particles include resin particles of acrylic resin, and the suspension further contains a dispersant made of a fatty acid adapted to disperse the resin particles in the liquid medium.

5 . A fuel cell separator material in a plate shape, the fuel cell separator material being a material for a fuel cell separator having formed thereon a gas flow channel through which one of fuel gas or oxidant gas to be supplied to a fuel cell flows, the fuel cell separator material comprising:
a metal substrate; a carbon layer covering the metal substrate; and a resin layer covering the carbon layer.

6 . The fuel cell separator material according to claim 5 ,
wherein: the metal substrate is a titanium substrate containing one of titanium or titanium alloy, and the carbon layer includes a mixture layer containing carbon black and titanium oxide holding the carbon black.

7 . The fuel cell separator material according to claim 5 ,
wherein: the resin layer contains thermoplastic resin as a base material of the resin layer, and a lubricant dispersed in the resin layer, the thermoplastic resin includes acrylic resin, and the lubricant is a fatty acid.

Assignees

• Toyota Motor Co Ltd

Inventors

• Sanada Yoshiyuki

Classifications

• H01M8/0221

  Organic resins; Organic polymers · CPC title

• C01B2204/32

  Size or surface area · CPC title

• H01M8/0228 Primary

  in the form of layered or coated products · CPC title

• H01M8/0206

  Metals or alloys · CPC title

• H01M8/0213

  Gas-impermeable carbon-containing materials · CPC title