Electrode for fuel cell and production method of electrode for fuel cell, membrane electrode assembly and fuel cell

Patent metadata

Field	Value
Publication number	US-9692058-B2
Application number	US-201214417951-A
Country	US
Kind code	B2
Filing date	Aug 2, 2012
Priority date	Aug 2, 2012
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

This electrode for fuel cell comprises: carbon nanotubes; a catalyst for fuel cell supported on the carbon nanotubes; and an ionomer provided to coat the carbon nanotubes and the catalyst for fuel cell, wherein when a length of the carbon nanotubes is represented by La [μm] and an inter-core pitch of the carbon nanotubes is represented by Pa [nm], the length La and the inter-core pitch Pa satisfy two expressions given below: 30≦La≦240; and 0.351×La+75≦Pa≦250.

First claim

The invention claimed is:

1. An electrode for fuel cell, comprising:
(1) carbon nanotubes;
(2) a catalyst for fuel cell supported on the carbon nanotubes, wherein the catalyst and carbon nanotubes form a catalyst layer; and
(3) an ionomer coated on the carbon nanotubes and the catalyst for fuel cell,
wherein when
a length of the carbon nanotubes is represented by La um and
an inter-core pitch of the carbon nanotubes is represented by Pa nm,

the length La and the inter-core pitch Pa satisfy two expressions given below:
30≦ La≦ 240;

170≦ Pa≦ 250; and

0.611× La+ 82.5≦ Pa≦ 1.333× La+ 190; and

wherein the carbon nanotubes joined with the electrolyte membrane by thermal pressure and the catalyst layer subsequently compressed to a thickness of no less than 7.5 um and no more than 17.5 um.

2. The electrode for fuel cell according to claim 1 , wherein
the length La and the inter-core pitch Pa satisfy an expression given below:
0.78× La+ 78≦ Pa≦ 1.333× La+ 150.

3. The electrode for fuel cell according to claim 1 , wherein the ionomer coats the carbon nanotubes in a thickness of no less than 2.5 nm and no more than 15 nm.

4. The electrode for fuel cell according to claim 3 , wherein the ionomer coats the carbon nanotubes in a thickness of no less than 5 nm and no more than 12.5 nm.

5. The electrode for fuel cell according to claim 1 , wherein
the ionomer has solubility of oxygen that is higher than 10.9 mol/dm 3 .

6. The electrode for fuel cell according to claim 5 , wherein
the ionomer has solubility of oxygen that is equal to or higher than 20 mol/dm 3 .

7. The electrode for fuel cell according to claim 1 , wherein
the inter-core pitch Pa satisfies:
30≦ La≦ 210.

8. The electrode for fuel cell according to claim 7 , wherein
the length La and the inter-core pitch Pa satisfy an expression given below:
0.78× La+ 78≦ Pa≦ 1.333× La+ 150.

9. The electrode for fuel cell according to claim 7 , wherein the ionomer coats the carbon nanotubes in a thickness of no less than 2.5 nm and no more than 15 nm.

10. The electrode for fuel cell according to claim 9 , wherein the ionomer coats the carbon nanotubes in a thickness of no less than 5 nm and no more than 12.5 nm.

11. The electrode for fuel cell according to claim 7 , wherein
the ionomer has solubility of oxygen that is higher than 10.9 mol/dm 3 .

12. The electrode for fuel cell according to claim 11 , wherein
the ionomer has solubility of oxygen that is equal to or higher than 20 mol/dm 3 .

Assignees

• Hasegawa Shigeki
• Murata Shigeaki
• Imanishi Masahiro
• Namba Ryoichi
• Toyota Motor Co Ltd

Inventors

• Hasegawa Shigeki
• Murata Shigeaki
• Imanishi Masahiro
• Namba Ryoichi

Classifications

• H01M4/8663

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title

• H01M4/8882

  Heat treatment, e.g. drying, baking · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M4/9083 Primary

  on carbon or graphite · CPC title