Gas diffusion electrode substrate, and membrane electrode assembly and fuel cell equipped with same

Patent metadata

Field	Value
Publication number	US-2017012297-A1
Application number	US-201515119163-A
Country	US
Kind code	A1
Filing date	Feb 17, 2015
Priority date	Feb 24, 2014
Publication date	Jan 12, 2017
Grant date	—

Abstract

A gas diffusion electrode substrate that is used in a fuel cell and is constituted by an electrode substrate and microporous parts, in which a microporous part (A) is formed on one surface of the electrode substrate with a thickness in the range of 10 μm or more and 60 μm or less, and in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 μm or more and less than 10 μm is within the range of 0.9 times or more and 5 times or less of the pore volume of pores with a pore size of 10 μm or more and less than 100 μm.

First claim

1 . A gas diffusion electrode substrate that is used in a fuel cell and is constituted by an electrode substrate and microporous parts, in which a microporous part (A) is formed on one surface of the electrode substrate with a thickness in the range of 10 μm or more and 60 μm or less, and in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 μm or more and less than 10 μm is within the range of 0.9 times or more and 5 times or less of the pore volume of pores with a pore size of 10 μm or more and less than 100 μm.

2 . The gas diffusion electrode substrate according to claim 1 , wherein the thickness of the electrode substrate is in the range of 50 μm or more and 190 μm or less.

3 . The gas diffusion electrode substrate according to claim 1 , wherein, in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.03 μm or more and less than 0.3 μm is smaller than the pore volume of pores with a pore size of 0.3 μm or more and less than 3 μm.

4 . The gas diffusion electrode substrate according to claim 1 , wherein, in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 μm or more and less than 10 μm is within the range of 1 time or more and 5 times or less of the pore volume of pores with a pore size of 10 μm or more and less than 100 μm.

5 . The gas diffusion electrode substrate according to claim 1 , which has a structure in which the microporous part (B) is impregnated in at least a part of the pores of the electrode substrate.

6 . The gas diffusion electrode substrate according to claim 5 , wherein, in the electrode substrate in which the microporous part (B) is impregnated, the pore volume of pores with a pore size of 0.03 μm or more and less than 0.3 μm is smaller than the pore volume of pores with a pore size of 0.3 μm or more and less than 3 μm.

7 . The gas diffusion electrode substrate according to claim 5 , wherein the microporous part (B) impregnates 20% or more and 70% or less of pores formed by the electrode substrate itself.

8 . The gas diffusion electrode substrate according to claim 5 , wherein the microporous part (B) has a porosity in the range of 50% or more and 90% or less.

9 . The gas diffusion electrode substrate according to claim 5 , wherein the porosity of the microporous part (B) is larger than the porosity of the microporous part (A) by 5% or more.

10 . The gas diffusion electrode substrate according to claim 5 , wherein the microporous part (B) contains a filler having an aspect ratio of 30 or more and 5000 or less.

11 . The gas diffusion electrode substrate according to claim 10 , wherein the filler is a fibrous carbon having a diameter of 1 nm or more and 500 nm or less.

12 . The gas diffusion electrode substrate according to claim 5 , wherein the microporous part (B) contains a water repellent agent having a melting point of 200° C. or more and 320° C. or less.

13 . The gas diffusion electrode substrate according to claim 5 , wherein the microporous part (B) contains a water repellent agent and a carbon based filler, and the mass ratio of the water repellent agent is 5% by mass or more and 50% by mass or less, based on the carbon based filler.

14 . The gas diffusion electrode substrate according to claim 1 , wherein the electrode substrate has, as compared to the surface roughness on the side where the microporous part (A) is formed, the surface roughness on the opposite side is larger with a difference of 1 μm or more and 5 μm or less.

15 . A membrane electrode assembly having catalyst layers on both sides of the electrolyte membrane, and further having the gas diffusion electrode substrate as defined in claim 1 on the outer side of the catalyst layers.

16 . A fuel cell having bipolar plates on both sides of the membrane electrode assembly as defined in claim 15 .

Assignees

• Toray Industries

Inventors

• Tanimura Yasuaki
• Utsunomiya Masamichi
• Kamae Toshiya
• Okano Yasutaka

Classifications

• H01M8/0243 Primary

  in the form of mixtures · CPC title

• H01M8/0239

  Organic resins; Organic polymers · CPC title

• H01M8/0234

  Carbonaceous material · CPC title

• H01M8/0245 Primary

  in the form of layered or coated products · CPC title

• Y02E60/50

  Fuel cells · CPC title