Fuel cell unit

Patent metadata

Field	Value
Publication number	US-12255361-B2
Application number	US-202017616261-A
Country	US
Kind code	B2
Filing date	May 7, 2020
Priority date	Jun 5, 2019
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

Fuel cell unit in the form of a fuel cell stack for producing electrical energy in an electrochemical manner, comprising fuel cells, the fuel cells each comprising a proton exchange membrane, an anode, a cathode, a gas diffusion layer, a bipolar plate, at least one fluid channel for the passage of a fluid, at least one seal ( 11 ) composed of a sealing material ( 42 ) for sealing off the at least one fluid channel ( 37 ), wherein particles ( 41 ) composed of a particle material ( 43 ) are arranged in the sealing material ( 42 ) of the at least one seal ( 11 ), for the purpose of extending the diffusion path ( 38 ) of the fluid which is sealed off by the at least one seal ( 11 ).

First claim

What is claimed is:

1. A fuel cell unit ( 1 ) as fuel cell stack ( 1 ) for electrochemically generating electric energy, the fuel cell unit comprising
fuel cells ( 2 ) each comprising a proton exchange membrane ( 5 ), an anode ( 7 ), a cathode ( 8 ), a gas diffusion layer ( 9 ), a bipolar plate ( 10 ),
at least one fluid channel ( 37 ) for passage of a fluid, and
at least one seal ( 11 ) composed of a sealing material ( 42 ) for sealing the at least one fluid channel ( 37 ),
wherein
particles ( 41 ) composed of a particle material ( 43 ) are arranged in the sealing material ( 42 ) of the at least one seal ( 11 ) in order to lengthen a diffusion path ( 38 ) of the fluid sealed off by the at least one seal ( 11 ),
wherein imaginary planes ( 54 ) spanned by the particles ( 41 ) are oriented within 5 degrees of perpendicular to an ideal direction of diffusion ( 53 ) in the at least one seal ( 11 ).

2. The fuel cell unit as claimed in claim 1 ,
wherein
a coefficient of diffusion of the particle material ( 43 ) of the particles ( 41 ) in the at least one seal ( 11 ) is smaller than a coefficient of diffusion of the sealing material ( 42 ).

3. The fuel cell unit as claimed in claim 1 ,
wherein
an aspect ratio of the particles ( 41 ) is greater than 1.

4. The fuel cell unit as claimed in claim 1 ,
wherein
the particles ( 41 ) have a platelet shape or needle shape.

5. The fuel cell unit as claimed in claim 1 ,
wherein
the particles ( 41 ) are anisotropic.

6. The fuel cell unit as claimed in claim 1 ,
wherein
the particle material ( 43 ) comprises a polarizable material and/or a material having a dipole nature so that the particles ( 41 ) overall have a dipole nature for orientation of the particles ( 41 ) in an electric field.

7. The fuel cell unit as claimed in claim 1 ,
wherein
the particle material ( 43 ) comprises a ferromagnetic material for orientation of the particles in a magnetic field.

8. The fuel cell unit as claimed in claim 1 ,
wherein
a maximum diameter ( 46 ) of the particles ( 41 ) is less than 1000 μm.

9. The fuel cell unit as claimed in claim 1 ,
wherein
a maximum diameter ( 46 ) of the particles ( 41 ) is greater than 5 μm.

10. The fuel cell unit as claimed in claim 1 ,
wherein
a ratio of a proportion by volume and/or a proportion by mass between the particle material ( 43 ) and the sealing material ( 42 ) is in a range from 1% to 95%.

11. The fuel cell unit as claimed in claim 1 ,
wherein
an aspect ratio of the particles ( 41 ) is greater than 2.

12. The fuel cell unit as claimed in claim 1 ,
wherein
a maximum diameter ( 46 ) of the particles ( 41 ) is less than 700 μm.

13. The fuel cell unit as claimed in claim 1 ,
wherein
a maximum diameter ( 46 ) of the particles ( 41 ) is greater than 10 μm.

14. The fuel cell unit as claimed in claim 1 ,
wherein
a ratio of a proportion by volume and/or a proportion by mass between the particle material ( 43 ) and the sealing material ( 42 ) is in a range from 3% to 80%.

15. A process for producing a fuel cell unit ( 1 ), comprising the steps:
provision of components ( 5 , 6 , 7 , 8 , 9 , 10 ) for fuel cells ( 2 ),
provision of at least one seal ( 11 ) composed of a sealing material ( 42 ),
assembly of the components of the fuel cells ( 2 ) so that at least one fluid channel ( 37 ) is sealed by the at least one seal ( 11 ),
assembly of the fuel cells ( 2 ) to give the fuel cell unit ( 1 ), and
providing the at least one seal ( 11 ) with particles ( 41 ) composed of a particle material ( 43 ) being arranged in the sealing material ( 42 ) of the at least one seal ( 11 ) in order to lengthen a diffusion path ( 38 ) of the fluid sealed off by the at least one seal ( 11 ),
wherein imaginary planes ( 54 ) spanned by the particles ( 41 ) are oriented within 5 degrees of perpendicular to an ideal direction of diffusion ( 53 ) in the at least one seal ( 11 ).

16. The process as claimed in claim 15 ,
wherein
the particles ( 41 ) have a maximum diameter ( 46 ) in a first direction ( 44 ) and have a minimum diameter ( 47 ) in a second direction ( 45 ) and the first and second directions ( 44 , 45 ) are oriented perpendicular to one another.

17. The process as claimed in claim 13 ,
wherein
the at least one seal ( 11 ) is arranged in the electric and/or magnetic field and the particles ( 41 ) perform movements in the sealing material ( 42 ) during arrangement of the at least one seal ( 11 ) in the electric and/or magnetic field.

18. The process as claimed in claim 16 ,
wherein
the sealing material ( 42 ) of the at least one seal ( 11 ) is cured after orientation of the particles ( 41 ) in the at least one seal ( 11 ).

19. A fuel cell unit ( 1 ) as fuel cell stack ( 1 ) for electrochemically generating electric energy, the fuel cell unit comprising
fuel cells ( 2 ) each comprising a proton exchange membrane ( 5 ), an anode ( 7 ), a cathode ( 8 ), a gas diffusion layer ( 9 ), a bipolar plate ( 10 ),
at least one fluid channel ( 37 ) for passage of a fluid, and
at least one seal ( 11 ) composed of a sealing material ( 42 ) for sealing the at least one fluid channel ( 37 ),
wherein particles ( 41 ) composed of a particle material ( 43 ) are arranged in the sealing material ( 42 ) of the at least one seal ( 11 ) in order to lengthen a diffusion path ( 38 ) of the fluid sealed off by the at least one seal ( 11 ),
wherein a coefficient of diffusion of the particle material ( 43 ) of the particles ( 41 ) in the at least one seal ( 11 ) is smaller than a coefficient of diffusion of the sealing material ( 42 ).

20. The fuel cell unit as claimed in claim 19 , wherein the particle material ( 43 ) comprises a ferromagnetic material for orientation of the particles in a magnetic field.

Assignees

• Bosch Gmbh Robert

Inventors

• Ringk Andreas
• Ringel Anton

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/1004

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

• H01M8/0286

  Processes for forming seals · CPC title

• H01M8/0284

  Organic resins; Organic polymers · CPC title

• Y02E60/50

  Fuel cells · CPC title