Fuel cell stack having a displacement absorbing member disposed in a cooling fluid channel

Patent metadata

Field	Value
Publication number	US-10644329-B2
Application number	US-201314654987-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Dec 26, 2012
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

A fuel cell stack has a stacked plurality of single cells. Each of the single cells has a membrane electrode assembly, and a pair of separators sandwiching the membrane electrode assembly therebetween. A cooling fluid channel where a cooling fluid flows is formed between adjacent single cells. The fuel cell stack further comprises a displacement absorbing member disposed in the cooling fluid channel to absorb a displacement between the single cells. The displacement absorbing member comprises a channel flow resistance reduction structure that reduces a channel flow resistance of the cooling fluid channel against the cooling fluid.

First claim

The invention claimed is:

1. A fuel cell stack, comprising:
a stacked plurality of single cells, each of the single cells comprising a membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly therebetween; and
a displacement absorbing member comprising a base plate and a plurality of spring functional parts, the base plate comprising two opposite plane surfaces,
wherein the spring functional parts have a cantilever structure comprising a fixed proximal end fixed on the base plate and a free tip end,
wherein a cooling fluid channel where a cooling fluid flows in a flow direction is formed between adjacent single cells,
wherein the displacement absorbing member is disposed in the cooling fluid channel to absorb a displacement between the single cells, and comprises a cutout formed in an area from the free tip end to the fixed proximal end, forming a channel flow resistance reduction structure that reduces a channel flow resistance of the cooling fluid channel against the cooling fluid by preventing vortex flow of the cooling fluid,
wherein the spring functional parts arranged on one of the two opposite plane surfaces have different shapes according to a location in the cooling fluid channel, and
wherein the spring functional parts comprise the cutouts,
wherein the cutouts are smaller in size as the spring functional parts are positioned farther away from a center of the cooling fluid channel in a direction perpendicular to the flow direction and closer to outer sides of the cooling fluid channel in the direction perpendicular to the flow direction, and
wherein channel sizes of outer side areas of the cooling fluid channel in the direction perpendicular to the flow direction are smaller than central areas thereof.

2. The fuel cell stack according to claim 1 ,
wherein a projected area of the displacement absorbing member projected in the flow direction of the cooling fluid are reduced by the channel flow resistance reduction structure in an arbitrary location in the flow direction.

3. The fuel cell stack according to claim 1 ,
wherein a surface of the separator facing the cooling fluid channel has an uneven cross-sectional shape that extends in the flow direction of the cooling fluid, and
wherein the displacement absorbing member is configured such that a contacting part in contact with the separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

4. The fuel cell stack according to claim 2 ,
wherein a surface of the separator facing the cooling fluid channel has an uneven cross-sectional shape that continues in the flow direction of the cooling fluid, and
wherein the displacement absorbing member is configured such that a contacting part in contact with the separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

5. The fuel cell stack according to claim 1 ,
wherein the spring functional parts are formed by lancing the base plate.

6. The fuel cell stack according to claim 5 ,
wherein blank areas are formed on the base plate along a periphery of the spring functional parts.

7. The fuel cell stack according to claim 1 ,
wherein the channel flow resistance reduction structure is formed between the free tip end and the fixed proximal end of the spring functional parts.

8. The fuel cell stack according to claim 1 ,
wherein the spring functional parts have a width that decreases from the fixed proximal end to the free tip end.

9. The fuel cell stack according to claim 1 ,
wherein the free tip end of the spring functional parts faces toward a downstream of the flow direction of the cooling fluid.

10. The fuel cell stack according to claim 1 ,
wherein the spring functional parts are disposed at different intervals between adjacent spring functional parts according to a location in the cooling fluid channel.

11. The fuel cell stack according to claim 9 ,
wherein the channel flow resistance reduction structure comprises a pathway formed between the spring functional parts of the displacement absorbing member.

Assignees

• Nissan Motor
• Nhk Spring Co Ltd

Inventors

• Fukuyama Yosuke
• Iritsuki Keita
• Terada Yusuke
• Tajima Norihiro

Classifications

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• F28F2265/26

  for allowing differential expansion between elements · CPC title

• H01M8/2483

  characterised by internal manifolds · CPC title

• H01M8/0265

  the reactant or coolant channels having varying cross sections · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title