Fuel cell stack

Patent metadata

Field	Value
Publication number	US-9929426-B2
Application number	US-201214394365-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Apr 25, 2012
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A fuel cell stack is formed by stacking unit cells and each unit cell is formed by sandwiching a membrane electrode assembly between a pair of separators having depression parts and protrusion parts. A cooling liquid flow space is formed between the unit cells, and a displacement absorption member which absorbs displacement between the unit cells C is disposed in the flow space. The displacement absorption member includes a spring function part having a free end and a fixed end, and an intrusion prevention means which prevents the free end of the spring function part from intruding into the depression part. A displacement absorption function between the unit cells is well maintained, while size reduction of the fuel cell stack is achieved.

First claim

The invention claimed is:

1. A fuel cell stack formed by stacking unit cells, each unit cell comprising:
a membrane electrode assembly sandwiched between a pair of separators, each separator having a depression part and a protrusion part;
a cooling liquid flow space formed between separators of adjacent stacked unit cells; and
a displacement absorption member that absorbs displacement between the unit cells disposed in the cooling liquid flow space, the displacement absorption member including a spring part having a free end and a fixed end,
wherein a separator facing the spring part has an intrusion prevention part formed by the protrusion part that prevents the free end of the spring part from intruding into the depression part of the separator, and
wherein a width of the free end of the spring part is larger than a width of the depression part of the separator with which the spring part contacts.

2. A fuel cell stack according to claim 1 , wherein the displacement absorption member is disposed such that a movement direction of the free end of the spring part matches to a continuous direction of the depression part of the separator, and the free end contacts with the protrusion part of the separator.

3. A fuel cell stack according to claim 1 , wherein an upper surface of the protrusion part of the separator is planar.

4. A fuel cell stack according to claim 1 , wherein the displacement absorption member has a structure, in which a plurality of spring parts are arranged on one side of a substrate, said spring parts contacting the separator facing the spring part, the substrate contacting an opposing separator opposite the cooling liquid flow space from the separator facing the spring part,
the spring part has a cantilever structure in which a bottom end is the fixed end fixed to the substrate and a top end is the free end, and
the width of the free end of the spring part is larger than a width of the protrusion part of the separator with which the spring part contacts.

5. A fuel cell stack according to claim 4 , wherein the free ends of the spring parts make contact with a plurality of protrusion parts of the separator with which the spring parts contact.

6. A fuel cell stack according to claim 4 , wherein the substrate of the displacement absorption member has an opening on a lower side of each of the spring parts, and the depression part of the separator, with which the substrate contacts, communicates with the opening.

7. A fuel cell stack according to claim 4 , wherein the displacement absorption member has the spring parts arranged on the substrate in a continuous direction of the protrusion part and the depression part of the separator, and in a width direction that intersects the continuous direction, and the spring parts that are adjacent in the width direction are shifted in the continuous direction of the protrusion part and the depression part.

8. A fuel cell stack according to claim 4 , wherein at least one of the spring parts of the displacement absorption member is disposed in a state where the free end is directed to a downstream side of a cooling liquid flow direction.

9. A fuel cell stack according to claim 1 , wherein a cooling liquid flow direction in the cooling liquid flow space and a gas flow direction in a gas passage formed between the membrane electrode assembly and one of the pair of separators are the same.

10. A fuel cell stack according to claim 9 , wherein a gas in the gas passage is an anode gas.

11. A fuel cell stack according to claim 1 , wherein each separator has a front/back reversible shape.

12. A fuel cell stack formed by stacking unit cells, each unit cell comprising:
a membrane electrode assembly sandwiched between a pair of separators, each separator having a depression part and a protrusion part;
a cooling liquid flow space formed between separators of adjacent stacked unit cells; and
a displacement absorption member that absorbs displacement between the unit cells disposed in the cooling liquid flow space, the displacement absorption member including a spring part having a free end and a fixed end,
wherein a separator facing the spring part has an intrusion prevention part formed in the depression part on a flow space side of the separator that prevents of the free end of the spring part from intruding into the depression part of a spring facing separator, and
wherein the intrusion prevention part is a retaining portion that protrudes on the flow space side to prevent the displacement absorption member from falling.

13. A fuel cell stack according to claim 12 , wherein the displacement absorption member is disposed such that a movement direction of the free end of the spring part matches to a direction orthogonal to a continuous direction of the depression part of the separator, and the free end contacts with the protrusion part of the separator.

14. A fuel cell stack according to claim 12 , wherein the displacement absorption member has a structure in which a plurality of the spring parts are disposed on one side of a substrate, the spring part has a cantilever structure in which a bottom end is the fixed end to the substrate, and a top end is the free end, and the retaining portion is provided in the depression part of the separator disposed on a free end side of the spring parts.

15. A fuel cell stack according to claim 14 , wherein the separator provided with the retaining portion is the separator on an anode side of the membrane electrode assembly.

16. A fuel cell stack according to claim 12 , wherein the retaining portion has a same protrusion height as the protrusion part on the flow space side of the separator.

17. A fuel cell stack according to claim 12 , wherein the retaining portion has a smaller width than the width of the depression part of the separator.

18. A fuel cell stack according to claim 12 , comprising a plurality of retaining portions regularly disposed in the depression part of the separator, with each retaining portion having the same shape.

19. A fuel cell stack according to claim 12 , comprising a plurality of retaining portions disposed in a laterally alternating fashion at a predetermined interval along a continuous direction of the depression part of the separator.

20. A fuel cell stack according to claim 14 , comprising a plurality of retaining portions respectively provided in a continuous direction of the depression part of the separator at positions corresponding to both sides of the spring part of the displacement absorption member in a width direction of the spring part.

21. A fuel cell stack according to claim 14 , wherein the retaining portion is larger than a width of the spring part of the displacement absorption member in a continuous direction of the depression part of the separator.

22. A fuel cell stack according to claim 14 , comprising a plurality of retaining portions, wherein a pitch of the retaining portions disposed at a predetermined interval and a pitch of the spring parts disposed at a predetermined interval are equivalent in a continuous direction of the depression part of the separator.

23. A fuel cell stack according to claim 14 , comprising a plurality of retaining portions, wherein a pitch of the retaining portions disposed at a predetermined interval and a pitch of the spring parts disposed at a predetermined interval are equivalent in a direction of arrangement of the protrusions and depressions of the separator.

Assignees

• Nissan Motor

Inventors

• Fukuyama Yosuke
• Iritsuki Keita

Classifications

• H01M8/006 Primary

  Flat · CPC title

• H01M8/0267

  having heating or cooling means, e.g. heaters or coolant flow channels · CPC title

• H01M8/04029

  Heat exchange using liquids · CPC title

• H01M8/241 Primary

  with solid or matrix-supported electrolytes · CPC title

• H01M8/248

  Means for compression of the fuel cell stacks · CPC title