Stretched catalyst layer having porous ionomer film and method of producing same

Patent metadata

Field	Value
Publication number	US-10734657-B2
Application number	US-201715445194-A
Country	US
Kind code	B2
Filing date	Feb 28, 2017
Priority date	Feb 28, 2017
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A membrane electrode assembly is provided that includes a polymer electrolyte membrane and a catalyst layer provided on a surface of the polymer electrolyte membrane. The catalyst layer comprises catalyst particles and an ionomer film surrounding each of the catalyst particles. The ionomer film has an oxygen permeability of approximately 6.0×10 12 mol/cm/s to 15.0×10 12 mol/cm/s at 80° C. and a relative humidity of approximately 30% to 100%.

First claim

What is claimed is:

1. A membrane electrode assembly comprising:
a polymer electrolyte membrane; and
a catalyst layer provided on a surface of the polymer electrolyte membrane,
the catalyst layer comprising catalyst particles and a porous ionomer film surrounding the catalyst particles, and
the catalyst layer having a plurality of spaces formed within the catalyst layer such that the porous ionomer film has an oxygen permeability of 6.0×10 12 mol/cm/s to 15.0×10 12 mol/cm/s at 80° C. and a relative humidity of 30% to 100% when measured using chronoamperometric analysis of the catalyst layer,
the catalyst particles comprising carbon support particles and at least one noble metal particle provided on a surface of the carbon support particles.

2. The membrane electrode assembly according to claim 1 , wherein
the noble metal particle comprises at least one selected from the group consisting of: ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold and alloys thereof.

3. The membrane electrode assembly according to claim 2 , wherein
the noble metal particle is a platinum particle.

4. The membrane electrode assembly according to claim 1 , wherein
the porous ionomer film comprises a fluoropolymer.

5. The membrane electrode assembly according to claim 4 , wherein
the fluoropolymer is perfluorosulfonic acid.

6. The membrane electrode assembly according to claim 1 , wherein
the catalyst layer has a porosity of 30 volume % to 40 volume % with respect to a total volume of the catalyst layer.

7. The membrane electrode assembly according to claim 1 , further comprising
a gas diffusion layer provided on a surface of the catalyst layer that is opposite the polymer electrolyte membrane.

8. The membrane electrode assembly according to claim 1 , wherein
the catalyst layer is a cathode side catalyst layer.

9. A fuel cell comprising:
the membrane electrode assembly according to claim 1 ,
an anode on a first side of the membrane electrode assembly;
a cathode on a second side of the membrane electrode assembly;
an anode gas diffusion layer on a side of the anode that is opposite the membrane electrode assembly; and
a cathode gas diffusion layer on a side of the cathode that is opposite the membrane electrode assembly.

10. The fuel cell according to claim 9 , wherein
the catalyst layer is a cathode side catalyst layer.

11. The membrane electrode assembly according to claim 1 , wherein
the porous ionomer film consists essentially of a single fluoropolymer-containing compound.

12. The membrane electrode assembly according to claim 1 , wherein
the porous ionomer film has a thickness of 1 nm to 10 nm.

13. The membrane electrode assembly according to claim 1 , wherein
the porous ionomer film is gapped such that its oxygen permeability is greater than that of an ungapped ionomer film having a same composition as that of the porous ionomer film.

Assignees

• Nissan North America Inc

Inventors

• Yadav Rameshwar

Classifications

• Y02E60/50

  Fuel cells · CPC title

• B32B2038/0028

  Stretching, elongating · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• B32B2313/04

  Carbon · CPC title

• B32B37/025

  Transfer laminating · CPC title