Fuel cell membrane electrode assemblies

Patent metadata

Field	Value
Publication number	US-11670790-B2
Application number	US-201916694305-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Nov 25, 2019
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A fuel cell membrane electrode assembly including a polymer electrolyte membrane (PEM) and first and second electrodes. The PEM is situated between the first and second electrodes. The first electrode includes a first catalyst material layer including a first catalyst material and having first and second surfaces. The first electrode includes first and second material layers adjacent to the first and second surfaces, respectively, of the first catalyst material. The first material layer faces away from the PEM and the second material layer faces the PEM. The first material layer comprises a graphene-based material layer having a number of defects configured to mitigate dissolution of the first catalyst material through the first material layer.

First claim

What is claimed is:

1. A fuel cell membrane electrode assembly comprising:
a polymer electrolyte membrane; and
first and second electrodes, the polymer electrolyte membrane situated between the first and second electrodes, the first electrode including a first catalyst material layer including a first catalyst material and having first and second surfaces, the first electrode including first and second material layers adjacent to the first and second surfaces, respectively, of the first catalyst material layer, the first material layer facing away from the polymer electrolyte membrane and the second material layer facing the polymer electrolyte membrane, the first material layer comprised of a first graphene-based material layer having a first number of defects configured to mitigate dissolution of the first catalyst material through the first material layer, the first catalyst layer including a number of clusters of the first catalyst material, and the number of clusters defining a number of void spaces therebetween having a volume of 1 nm 3 to 1 μm 3 .

2. The fuel cell membrane electrode assembly of claim 1 , wherein the second material layer is comprised of a second graphene-based material layer having a second number of defects configured to mitigate dissolution of the first catalyst material through the second material layer.

3. The fuel cell membrane electrode assembly of claim 1 , wherein the first and/or second material layers are first and/or second thin films, respectively.

4. The fuel cell membrane electrode assembly of claim 1 , wherein the first catalyst material includes pure Pt; a Pt-M alloy where M is a metal other than Pt; a platinum group member metal; an alloy of a platinum group member metal and a metal other than Pt; an alloy of platinum, a platinum group member metal, and a metal other than Pt; or combinations thereof.

5. The fuel cell membrane electrode assembly of claim 1 , wherein the number of void spaces configured to change a shape of the first material layer comprised of the graphene-based material layer over a number of operating cycles of a fuel cell containing the fuel cell membrane electrode assembly.

6. The fuel cell membrane electrode assembly of claim 1 , wherein the graphene-based material layer includes graphene, graphene oxide, reduced graphene oxides or combinations thereof.

7. The fuel cell membrane electrode assembly of claim 1 , wherein the second material layer is a catalyst support layer configured to support the first catalyst material layer.

8. The fuel cell membrane electrode assembly of claim 1 , wherein the first number of defects per unit volume of the first graphene-based material layer is 0.5 to 13%.

9. A fuel cell membrane electrode assembly comprising:
a polymer electrolyte membrane; and
first and second electrodes, the polymer electrolyte membrane situated between the first and second electrodes, the first electrode including a first catalyst material layer including a first catalyst material and having first and second surfaces, the first electrode including first and second graphene-based material layers adjacent to the first and second surfaces, respectively, of the first catalyst material, the first graphene-based material layer facing away from the polymer electrolyte membrane and the second graphene-based material layer facing the polymer electrolyte membrane, the first catalyst layer including a number of clusters of the first catalyst material, and the number of clusters defining a number of void spaces therebetween having a volume of 1 nm 3 to 1 μm 3 .

10. The fuel cell membrane electrode assembly of claim 9 , wherein the first catalyst material includes pure Pt; a Pt-M alloy where M is a metal other than Pt; a platinum group member metal; an alloy of a platinum group member metal and a metal other than Pt; an alloy of platinum, a platinum group member metal, and a metal other than Pt; or combinations thereof.

11. The fuel cell membrane electrode assembly of claim 9 , wherein the number of void spaces form an interface between the first graphene-based material layer and the first catalyst material and between the second graphene-based material layer and the first catalyst material.

12. The fuel cell membrane electrode assembly of claim 11 , wherein the interface includes first wrinkled portions of the first graphene-based material layer and second wrinkled portions of the second graphene-based material layer.

13. The fuel cell membrane electrode assembly of claim 9 , wherein one or more of the number of void spaces are filled with one or more conducting agents other than the first catalyst material.

14. The fuel cell membrane electrode assembly of claim 9 , wherein a percentage of a void space of the number of void spaces to a volume occupied by the number of clusters of the first catalyst material is in a range of 25% to 60%.

15. The fuel cell membrane electrode assembly of claim 9 , wherein the first graphene-based material layer having a first number of defects per unit volume of the first graphene-based material layer of 7 to 13%, and the second graphene-based material layer having a second number of defects per unit volume of the second graphene-based material layer of 0.5 to 6%.

16. A fuel cell membrane electrode assembly comprising:
a polymer electrolyte membrane; and
first and second electrodes including first and second bulk materials, the polymer electrolyte membrane situated between the first and second electrodes, the first bulk material including a first number of catalyst units discretely dispersed therein, the catalyst units each comprised of a catalyst material layer including a catalyst material and having first and second surfaces and first and second material layers adjacent to the first and second surfaces, respectively, of the catalyst material layer, the first material layer of each catalyst unit comprised of a graphene-based material layer having a number of defects configured to mitigate dissolution of the catalyst material through the graphene-based material layer, the number of defects per unit volume of the graphene-based material layer is 0.5 to 13%, and a width of the first number of catalyst units is 10 nm to 100 μm, a length of the first number of catalyst units is 10 nm to 100 μm, and a thickness is 1 to 20 nm.

17. The fuel cell membrane electrode assembly of claim 16 , wherein the second bulk material includes a second number of catalyst units dispersed therein, the first electrode is a cathode and the second electrode is an anode, and the first number is greater than the second number.

18. The fuel cell membrane electrode assembly of claim 17 , wherein a ratio of the first number to the second number is in a range of 2:1 to 5:4.

19. The fuel cell membrane electrode assembly of claim 16 , wherein the first bulk material is an ionomer forming an ionomer network between the first number of catalyst units.

20. The fuel cell membrane electrode assembly of claim 19 , wherein the second material layer of each catalyst unit is a catalyst support layer of an amorphous carbon material, a metal oxide, or a combination thereof.

Assignees

• Bosch Gmbh Robert

Inventors

• Kim Soo
• Mailoa Jonathan
• Schultz Timothy
• Craig Nathan
• Krishnamoorthy Uma
• Christensen Jake

Classifications

• H01M4/8673

  Electrically conductive fillers · CPC title

• H01M8/1004 Primary

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

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/8825

  Methods for deposition of the catalytic active composition · CPC title

• H01M8/1039

  halogenated, e.g. sulfonated polyvinylidene fluorides · CPC title