Catalyst layer with extended surface area and method of forming such catalyst layer for polymer electrolyte fuel cells

Patent metadata

Field	Value
Publication number	US-12170379-B2
Application number	US-201917296888-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Nov 26, 2018
Publication date	Dec 17, 2024
Grant date	Dec 17, 2024

Abstract

A manufacturing process includes: depositing a catalyst support on a gas diffusion layer to form a catalyst support-coated gas diffusion layer; depositing a catalyst on the catalyst support-coated gas diffusion layer to form a catalyst-coated gas diffusion layer; and depositing an ionomer on the catalyst-coated gas diffusion layer to form an ionomer-coated gas diffusion layer. A membrane electrode assembly for a fuel cell includes: a gas diffusion layer; a polymer electrolyte membrane; and a catalyst layer disposed between the gas diffusion layer and the polymer electrolyte membrane, wherein the catalyst layer includes an ionomer, and a concentration of the ionomer varies within the catalyst layer according to a concentration profile.

First claim

What is claimed is:

1. A manufacturing process comprising:
depositing a catalyst support on a gas diffusion layer to form a catalyst support-coated gas diffusion layer;
depositing, by atomic layer deposition, a catalyst layer on the catalyst support-coated gas diffusion layer to form a catalyst-coated gas diffusion layer; and
depositing an ionomer on the catalyst-coated gas diffusion layer to form an ionomer-coated gas diffusion layer;
wherein:
depositing the catalyst support is decoupled from depositing the catalyst layer;
depositing the ionomer is decoupled from depositing the catalyst layer;
depositing the ionomer comprises at least partially impregnating the ionomer into the catalyst layer, and the ionomer is deposited according to a concentration gradient wherein a concentration of the ionomer descends in a direction toward the gas diffusion layer; and
the catalyst layer is substantially alcohol-free.

2. The manufacturing process of claim 1 , wherein the catalyst support includes carbonaceous nanoparticles.

3. The manufacturing process of claim 1 , wherein depositing the catalyst support includes forming an ink composition including the catalyst support and a solvent, and applying the ink composition on the gas diffusion layer.

4. The manufacturing process of claim 3 , further comprising removing the solvent subsequent to applying the ink composition.

5. The manufacturing process of claim 1 , wherein the catalyst layer comprises a platinum group metal.

6. The manufacturing process of claim 1 , further comprising assembling the ionomer-coated gas diffusion layer with an anode-coated membrane to form an intermediate assembly, and laminating the intermediate assembly with another gas diffusion layer to form a membrane electrode assembly.

7. A membrane electrode assembly for a fuel cell, comprising:
a gas diffusion layer;
a polymer electrolyte membrane; and
a catalyst layer disposed between the gas diffusion layer and the polymer electrolyte membrane, wherein the catalyst layer comprises an ionomer, and a concentration of the ionomer varies within the catalyst layer according to a concentration profile, wherein a concentration of the ionomer descends in a direction from the polymer electrolyte membrane toward the gas diffusion layer;
wherein the catalyst layer is substantially alcohol-free,
wherein the membrane electrode assembly is produced by a manufacturing process comprising:
depositing a catalyst support on the gas diffusion layer to form a catalyst support-coated gas diffusion layer;
depositing, by atomic layer deposition, the catalyst layer on the catalyst support-coated gas diffusion layer to form a catalyst-coated gas diffusion layer;
depositing the ionomer on the catalyst-coated gas diffusion layer to form an ionomer-coated gas diffusion layer, and
contacting the catalyst layer with the polymer electrolyte membrane, wherein:
depositing the catalyst support is decoupled from depositing the catalyst layer:
depositing the ionomer is decoupled from depositing the catalyst layer;
depositing the ionomer comprises at least partially impregnating the ionomer into the catalyst layer.

8. A fuel cell comprising the membrane electrode assembly of claim 7 .

Assignees

• Univ Leland Stanford Junior
• Volkswagen Ag

Inventors

• Xu Shicheng
• Prinz Friedrich B
• Schladt Thomas
• Graf Tanja
• Mueller Jonathan Edward
• Kirsch Sebastian
• Huebner Gerold
• Glavas Vedran

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/1004

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

• H01M4/926 Primary

  on carbon or graphite · CPC title

• H01M4/8892

  Impregnation or coating of the catalyst layer, e.g. by an ionomer · CPC title

• H01M4/8867

  Vapour deposition · CPC title