Fuel cell, fuel cell stack and method of operating a fuel cell stack

Patent metadata

Field	Value
Publication number	US-11721817-B2
Application number	US-202017781752-A
Country	US
Kind code	B2
Filing date	Nov 5, 2020
Priority date	Dec 4, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

The invention relates to a fuel cell ( 1 ) for a fuel cell stack ( 11 ), comprising a polymer membrane ( 2 ) which serves as an electrolyte and has respectively on both sides a catalyst layer ( 3, 4 ) for forming an anode ( 3 ) on the one side and a cathode ( 4 ) on the other side, a gas diffusion layer ( 5 ) and a bipolar plate ( 6 ) being applied to each of the two analyst layers ( 3, 4 ). According to the invention, a short-circuit element ( 7 ) is applied, preferably printed, to at least one bipolar plate ( 6 ), namely on the side facing away from the gas diffusion layer ( 5 ). The invention also relates to a fuel cell stack ( 11 ) and to a method for operating a fuel cell stack ( 11 ).

First claim

The invention claimed is:

1. A fuel cell ( 1 ) for a fuel cell stack ( 11 ), comprising a polymer membrane ( 2 ) which serves as an electrolyte and which comprises on either side a catalyst layer ( 3 , 4 ) for forming an anode ( 3 ) on one side and a cathode ( 4 ) on the other, the two catalyst layers ( 3 , 4 ) each bearing an applied gas diffusion layer ( 5 ) and also an applied bipolar plate ( 6 ), wherein at least one bipolar plate ( 6 ) bears an applied, short-circuit element ( 7 ) on a side facing away from the gas diffusion layer ( 5 ) of a respective catalyst layer ( 3 , 4 ).

2. The fuel cell ( 1 ) as claimed in claim 1 , wherein the short-circuit element ( 7 ) is an elastically deformable element.

3. The fuel cell ( 1 ) as claimed in claim 1 , wherein the short-circuit element ( 7 ) bounds a pressurizable pressure compartment ( 8 ).

4. The fuel cell ( 1 ) as claimed in claim 3 , wherein the pressure compartment ( 8 ) is pressurizable via a side channel ( 9 ).

5. The fuel cell ( 1 ) as claimed in claim 1 , wherein the bipolar plate ( 6 ) and the short-circuit element ( 7 ) bear at least regionally an applied seal ( 10 ).

6. The fuel cell ( 1 ) as claimed in claim 1 , wherein the short-circuit element ( 7 ) comprises different zones (A, B, C) which differ in terms of their electrical resistance.

7. The fuel cell ( 1 ) as claimed in claim 1 , wherein the short-circuit element ( 7 ) is a printed short-circuit element.

8. The fuel cell ( 1 ) as claimed in claim 2 , wherein the elastically deformable short-circuit element ( 7 ) is a plate or a membrane.

9. The fuel cell ( 1 ) as claimed in claim 3 , wherein the short-circuit element ( 7 ), together with the bipolar plate ( 6 ), bounds the pressurizable pressure compartment ( 8 ).

10. The fuel cell ( 1 ) as claimed in claim 4 , wherein the side channel ( 9 ) is formed in the bipolar plate ( 6 ) and/or traverses the bipolar plate ( 6 ).

11. The fuel cell ( 1 ) as claimed in claim 5 , wherein the seal ( 10 ) is printed.

12. The fuel cell ( 1 ) as claimed in claim 5 , wherein the seal ( 10 ) circumferentially surrounds and/or completely covers the short-circuit element ( 7 ).

13. A fuel cell stack ( 11 ) comprising at least two fuel cells ( 1 ) as claimed in claim 1 , the fuel cells ( 1 ) being stacked such that the respective short-circuit elements ( 7 ) are disposed one above another in a mirrored disposition and in the event of a short circuit make contact with one another in a region of a common short-circuit face ( 12 ).

14. A method for operating the fuel cell stack ( 11 ) as claimed in claim 13 , wherein the short-circuit elements ( 7 ) are selectively engaged and disengaged via a central pressure supply.

15. The method as claimed in claim 14 , wherein the short-circuit elements ( 7 ) are pressurized via the central pressure supply and elastically deformed.

16. The method as claimed in claim 15 , wherein the pressurization is carried out using a gas or a liquid.

17. The method as claimed in claim 16 , wherein the gas is hydrogen or air.

18. The method as claimed in claim 16 , wherein the liquid is a coolant.

Assignees

• Bosch Gmbh Robert

Inventors

• Kemmer Helerson
• Weeber Kai

Classifications

• H01M8/04246 Primary

  Short circuiting means for defective fuel cells (detection of defective fuel cells H01M8/04664, methods for shunting fuel cells H01M8/04955) · CPC title

• H01M8/0247

  characterised by the form (characterised by a channel configuration H01M8/0258) · CPC title

• H01M8/1004

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

• H01M8/1065

  characterised by the form, e.g. perforated or wave-shaped · CPC title

• H01M8/2457

  with both reactants being gaseous or vaporised · CPC title