Separator for fuel cells, fuel cell, fuel cell stack, and method of manufacturing separator for fuel cells

Patent metadata

Field	Value
Publication number	US-10629917-B2
Application number	US-201314650236-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Dec 7, 2012
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A separator for fuel cells is provided. The separator includes: a base material; an underlying plate layer formed on the base material; and a gold plate layer formed on the underlying plate layer by means of electroless plating. The separator is characterized in that a face of the underlying plate layer facing the gold plate layer has an arithmetic average roughness Ra of 80 nm or less. According to the present invention, there can be provided a separator for fuel cells in which the gold plate layer can be uniformly formed for irregular parts that constitute gas flow channels and the occurrence of unformed parts and pinholes in the gold plate layer is prevented without increasing the film thickness of the gold plate layer and which is excellent in the corrosion resistance and the conductivity.

First claim

What is claimed is:

1. A separator for fuel cells comprising:
a base material composed of Al or Al alloy, the base material having a modifying layer which contains Ni—P formed on a surface thereof;
an underlying plate layer which contains Ni—P and has a thickness of 0.01 to 2 μm formed on the base material via the modifying layer; and
a gold plate layer formed on the underlying plate layer by means of electroless substitution plating process,
wherein a weight content ratio of P in the modifying layer is higher than a weight content ratio of P in the underlying plate layer,
wherein a face of the underlying plate layer facing the gold plate layer has an arithmetic average roughness of 80 nm or less, and
wherein a thickness of the gold plate layer is 1 to 72 nm.

2. The separator for fuel cells according to claim 1 , wherein the underlying plate layer is formed on the base material of which a surface was preliminarily polished by using at least one method of mechanical polishing, chemical polishing, and chemical mechanical polishing.

3. The separator for fuel cells according to claim 1 , wherein the underlying plate layer is formed by using a plating bath that contains a brightening agent.

4. The separator for fuel cells according to claim 1 , wherein the underlying plate layer has a surface that is polished by using at least one method of mechanical polishing, chemical polishing, and chemical mechanical polishing after the underlying plate layer was formed on the base material.

5. A fuel cell configured using the separator for fuel cells according to claim 1 .

6. A fuel cell configured using the separator for fuel cells according to claim 2 .

7. A fuel cell configured using the separator for fuel cells according to claim 3 .

8. A fuel cell configured using the separator for fuel cells according to claim 4 .

9. A fuel cell stack configured such that a plurality of the fuel cells according to claim 5 are stacked together.

10. A fuel cell stack configured such that a plurality of the fuel cells according to claim 6 are stacked together.

11. A fuel cell stack configured such that a plurality of the fuel cells according to claim 7 are stacked together.

12. A fuel cell stack configured such that a plurality of the fuel cells according to claim 8 are stacked together.

13. A method of manufacturing a separator for fuel cells comprising:
preparing a base material composed of Al or Al alloy, the base material having a modifying layer which contains Ni—P formed on a surface thereof;
forming an underlying plate layer which contains Ni—P and has a thickness of 0.01 to 2 μm on a surface of a base material via the modifying layer, the underlying plate layer having a surface that has an arithmetic average roughness Ra of 80 nm or less; and
forming a gold plate layer with a thickness of 1 to 72 nm on the underlying plate layer by means of a substitution plating process,
wherein a weight content ratio of P in the modifying layer is higher than a weight content ratio of P in the underlying plate layer.

14. The method of manufacturing a separator for fuel cells according to claim 13 , further comprising preliminary polishing a surface of the base material by using at least one method of mechanical polishing, chemical polishing, and chemical mechanical polishing before the forming an underlying plate layer.

15. The method of manufacturing a separator for fuel cells according to claim 13 , wherein the underlying plate layer is formed by using a plating bath that contains a brightening agent.

16. The method of manufacturing a separator for fuel cells according to claim 13 , further comprising polishing a surface of the underlying plate layer by using at least one method of mechanical polishing, chemical polishing, and chemical mechanical polishing after the forming an underlying plate layer.

Assignees

• Toyo Kohan Co Ltd

Inventors

• Mukai Nobuaki

Classifications

• C23C18/36

  using hypophosphites · CPC title

• H01M8/0228 Primary

  in the form of layered or coated products · CPC title

• C23C18/54

  Contact plating, i.e. electroless electrochemical plating · CPC title

• H01M8/0206 Primary

  Metals or alloys · CPC title

• C23C18/165

  Multilayered product (layered product B32B) · CPC title