Frameless fuel cell stack having hollow fasteners

Patent metadata

Field	Value
Publication number	US-2023096918-A1
Application number	US-202117491434-A
Country	US
Kind code	A1
Filing date	Sep 30, 2021
Priority date	Sep 30, 2021
Publication date	Mar 30, 2023
Grant date	—

Abstract

A fuel cell stack is provided that includes a top end plate, a bottom end plate, a plurality of fuel cells provided between the top end plate and the bottom end plate, at least one bipolar plate, a plurality of hollow fasteners, and a plurality of sleeves. Each of the at least one bipolar plate is formed between two of the plurality of fuel cells. The plurality of hollow fasteners and the plurality of sleeves extend through holes in each of the top end plate, the bottom end plate, the plurality of fuel cells and the at least one bipolar plate. Each of the plurality of sleeves surrounds one of the plurality of hollow fasteners. Each of the plurality of hollow fasteners comprises a top surface, a hole in the top surface, a side surface, and a plurality of holes formed in the side surface.

First claim

What is claimed is:

1 . A fuel cell stack comprising:
a top end plate; a bottom end plate; a plurality of fuel cells provided between the top end plate and the bottom end plate; at least one bipolar plate, each of the at least one bipolar plate formed between two of the plurality of fuel cells; a plurality of hollow fasteners extending through holes in each of the top end plate, the bottom end plate, the plurality of fuel cells and the at least one bipolar plate; and a plurality of sleeves extending through the holes in each of the top end plate, the bottom end plate, the plurality of fuel cells and the at least one bipolar plate, each of the plurality of sleeves surrounding one of the plurality of hollow fasteners, each of the plurality of hollow fasteners comprising: a top surface, a hole in the top surface, a side surface, and a plurality of holes formed in the side surface.

2 . The fuel cell stack according to claim 1 , wherein
the top end plate and the bottom end plate are each covered by a first coating comprising a ceramic material.

3 . The fuel cell stack according to claim 2 , wherein
each of the plurality of hollow fasteners is covered by a second coating comprising a first insulating material.

4 . The fuel cell stack according to claim 3 , wherein
the first coating and the second coating are formed of a same material.

5 . The fuel cell stack according to claim 1 , wherein
each of the plurality of sleeves is formed of a second insulating material.

6 . The fuel cell stack according to claim 1 , further comprising
for each of the plurality of sleeves, a gap between the sleeve and the one of the plurality of hollow fasteners.

7 . The fuel cell stack according to claim 1 , further comprising
a sealing gasket between each of the plurality of sleeves and the plurality of fuel cells.

8 . The fuel cell stack according to claim 1 , wherein
each of the plurality of fuel cells includes an anode comprising: a metal substrate having at least one hole formed therein; and an anode material formed on a surface of the metal substrate and within each of the at least one hole, and each of the plurality of hollow fasteners penetrates the metal substrate of each of the plurality of fuel cells.

9 . The fuel cell stack according to claim 1 , wherein
each of the plurality of fuel cells includes a solid oxide electrolyte.

10 . The fuel cell stack according to claim 1 , wherein
the bipolar plate includes at least one channel formed in a first surface and a second surface of the bipolar plate, and each of the at least one channel has a semi-circular shape and extends along the first surface and the second surface of the bipolar plate.

11 . The fuel cell stack according to claim 10 , wherein
the bipolar plate includes a third coating that covers the first surface and the second surface of the bipolar plate.

12 . The fuel cell stack according to claim 1 , wherein
for each of the plurality of hollow fasteners, the hole in the top surface forms a gas flow channel along a center axis of the hollow fastener.

13 . The fuel cell stack according to claim 12 , wherein
for each of the plurality of hollow fasteners, the plurality of holes formed in the side surface connect the gas flow channel to an exterior of the hollow fastener.

14 . The fuel cell stack according to claim 1 , further comprising
a positive electrode terminal and a negative electrode terminal between the top end plate and the bottom end plate.

15 . The fuel cell stack according to claim 1 , further comprising
a metal mesh formed between one of the at least one bipolar plate and a first one of the plurality of fuel cells; and a second metal mesh formed between the one of the at least one bipolar plate and a second one of the plurality of fuel cells.

16 . The fuel cell stack according to claim 10 , wherein
each of the plurality of sleeves includes a first channel that aligns with the at least one channel on the first surface of the bipolar plate and a second channel that aligns with the at least one channel on the second surface of the bipolar plate.

17 . The fuel cell stack according to claim 17 , wherein
the first channel and the second channel are each aligned with one of the plurality of holes formed in one of the plurality of hollow fasteners.

18 . The fuel cell stack according to claim 18 , wherein
the first channel and the second channel each extend through an entire thickness of the sleeve, each of the plurality of sleeves includes grooves adjacent to the first channel and the second channel, and the grooves do not extend through the entire thickness of the sleeve.

19 . The fuel cell stack according to claim 1 , wherein
the hollow fastener is a metal screw.

20 . A screw for a fuel cell stack comprising:
a metal screw having an exterior surface; and an insulating coating formed on the exterior surface of the metal screw, the metal screw having a gas flow channel formed along a center axis of the metal screw, and the metal screw having plurality of holes formed in the exterior surface, the plurality of holes connecting the gas flow channel to an exterior of the metal screw.

Assignees

• Nissan North America Inc

Inventors

• Patil Sandeep
• Abdul Jabbar Mohammed Hussain

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/0282

  Inorganic material · CPC title

• H01M8/0245

  in the form of layered or coated products · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/026 Primary

  characterised by grooves, e.g. their pitch or depth · CPC title