Membrane electrode assembly for a fuel cell, and fuel cell

Patent metadata

Field	Value
Publication number	US-2018233758-A1
Application number	US-201615751373-A
Country	US
Kind code	A1
Filing date	Aug 10, 2016
Priority date	Aug 12, 2015
Publication date	Aug 16, 2018
Grant date	—

Abstract

The invention relates to a membrane electrode assembly ( 15 ) for a fuel cell ( 10 ), comprising a membrane ( 11 ) on each side of which is disposed a catalytic layer ( 12, 13 ), and on this a gas diffusion layer ( 30 ).
It is provided that the gas diffusion layer ( 30 ) comprises a layer with electrically conductive particles ( 35 ), and a portion of the particles ( 35 ) is arranged directly adjacent to the catalytic layer ( 12, 13 ).

First claim

1 . A membrane electrode assembly for a fuel cell, comprising:
a membrane; a first catalytic layer positioned on a first surface of the membrane and a second catalytic layer positioned on a second surface of the membrane opposite to the first surface of the membrane; and a first gas diffusion layer positioned on the first catalytic layer and a second gas diffusion layer positioned on the second catalytic layer, wherein each of the first and second gas diffusion layers include electrically conductive particles, a portion of the particles of each of the first and second gas diffusion layers positioned immediately adjacent to the respective catalytic layer.

2 . The membrane electrode assembly according to claim 1 , wherein the electrically conductive particles have an average particle size in the range of 10 to 1000 μm.

3 . The membrane electrode assembly according to claim 1 , wherein the particles have different particle sizes, in particular with a variance in the range of 100 to 500 μm over the entire particle range.

4 . The membrane electrode assembly according to claim 1 , wherein the particles comprise at least two batches of particles, each batch of particles having a respective average particle size, and the at least two average particle sizes differ from one another by at least one error width.

5 . The membrane electrode assembly according to claim 3 , wherein the particles are arranged to have a gradient of the particle sizes which runs perpendicular to the first and second surfaces of the membrane.

6 . The membrane electrode assembly according to claim 3 , wherein the average particle size changes incrementally in a direction towards the catalytic layer.

7 . The membrane electrode assembly according to claim 3 , wherein the average particle size of the particles decreases in the direction towards the catalytic layer.

8 . The membrane electrode assembly according to claim 1 , wherein the particles include a graphite powder.

9 . The membrane electrode assembly according to claim 1 , wherein the gas diffusion layer has a cover layer on a surface facing away from the membrane.

10 . A fuel cell comprising a membrane electrode assembly including:
a membrane; a first catalytic layer positioned on a first surface of the membrane and a second catalytic layer positioned on a second surface of the membrane opposite to the first surface of the membrane; and a first gas diffusion layer positioned on the first catalytic layer and a second gas diffusion layer positioned on the second catalytic layer, wherein each of the first and second gas diffusion layers include electrically conductive particles, a portion of the particles of each of the first and second gas diffusion layers positioned immediately adjacent to the respective catalytic layer.

11 . The fuel cell according to claim 10 , wherein the particles comprise at least two batches of particles, each batch of particles having a respective average particle size, and the at least two average particle sizes differ from one another by at least one error width.

12 . The fuel cell according to claim 10 , wherein the average particle size changes incrementally in a direction towards the catalytic layer.

13 . The fuel cell according to claim 10 , wherein the average particle size of the particles decreases in the direction towards the catalytic layer.

14 . The fuel cell according to claim 10 , wherein the particles include a graphite powder.

15 . The fuel cell according to claim 10 , wherein the gas diffusion layer has a cover layer on a surface facing away from the membrane.

16 . A method of fabricating a membrane electrode assembly for a fuel cell, comprising:
positioning a first catalytic layer on a first surface of a membrane and a second catalytic layer on a second surface of the membrane opposite to the first surface of the membrane; and positioning a first gas diffusion layer on the first catalytic layer and a second gas diffusion layer on the second catalytic layer, wherein each of the first and second gas diffusion layers include electrically conductive particles, a portion of the particles of each of the first and second gas diffusion layers positioned immediately adjacent to the respective catalytic layer.

17 . The method according to claim 16 wherein the particles have an average particle size between 10 and 1000 μm.

18 . The method according to claim 16 wherein the particles have particle sizes that differ from one another by up to between 100 and 500 μm.

19 . The method according to claim 16 wherein the particles of the first gas diffusion layer are positioned so that a gradient exists in the size of the particles in a direction extending perpendicular to the first surface of the membrane.

Assignees

• Volkswagen Ag
• Audi Ag

Inventors

• Schmidt Lasse
• Göbel Martin
• Stiefel Miriam
• Ronnenberg Julian

Classifications

• H01M4/8807

  Gas diffusion layers · CPC title

• H01M8/1004 Primary

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

• H01M8/0234

  Carbonaceous material · CPC title

• H01M8/241

  with solid or matrix-supported electrolytes · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title