Carbon sheet, gas diffusion electrode substrate, and fuel cell

Patent metadata

Field	Value
Publication number	US-2019044153-A1
Application number	US-201615778839-A
Country	US
Kind code	A1
Filing date	Dec 8, 2016
Priority date	Dec 11, 2015
Publication date	Feb 7, 2019
Grant date	—

Abstract

A porous carbon sheet including at least carbon fibers, having a thickness of 30 to 95 μm, a gas permeation resistance of 0.5 to 8.8 Pa, and a tensile strength of 5 to 50 N/cm, and a gas diffusion electrode substrate including a porous carbon sheet containing at least carbon fibers, at least one surface thereof having a microporous layer containing at least an electric conductive filler, the gas diffusion electrode substrate being dividable in the thickness direction into a smaller pore part and a larger pore part, the larger pore part having a thickness of 3 to 60 μm.

First claim

1 . A porous carbon sheet comprising at least carbon fibers and having a thickness of 30 to 95 μm, a resistance to gas permeation of 0.5 to 8.8 Pa, and a tensile strength of 5 to 50 N/cm.

2 . A carbon sheet as, set forth in claim 1 , wherein the total area of through-pores accounts for 7% to 40% of the area of the carbon sheet, which accounts for 100%.

3 . A carbon sheet as set forth in either claim 1 , wherein the through-pores with a pore size of 25 μm or more exist at a rate of 5 pores/mm 2 or more.

4 . A carbon sheet as set forth in claim 1 that is in a continuous form.

5 . A production method for a carbon sheet as set forth in claim 4 , comprising a step for performing the heat-pressing (hereinafter referred to as heat-pressing step) of a continuous prepreg, the heat-pressing step being performed at an unwinding tension of 0.05 N/cm or less.

6 . A gas diffusion electrode substrate comprising a carbon sheet as set forth in claim 1 , at least one surface thereof having a microporous layer containing at least an electric conductive filler.

7 . A gas diffusion electrode substrate comprising a porous carbon sheet containing at least carbon fibers, at least one surface thereof having a microporous layer containing at least an electric conductive filler,
the gas diffusion electrode substrate being dividable in the thickness direction into a smaller pore part and a larger pore part, the larger pore part having a thickness of 3 to 60 μm.

8 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the thickness ratio between the smaller pore part and the larger pore part being 1:0.1 to 1:1.5.

9 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the thickness ratio between the smaller pore part and the larger pore part being 1:0.1 to 1:1.0.

10 . A gas diffusion electrode substrate as set forth in claim 7 having a thickness of 33 to 145 μm.

11 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the carbon sheet has a thickness of 30 to 95 μm.

12 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the carbon sheet has a tensile strength of 5 to 50 N/cm.

13 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the total area of through-pores accounts for 7% to 40% of the area of the carbon sheet, which accounts for 100%.

14 . A gas diffusion electrode substrate as set forth in claim 7 , wherein the carbon sheet contains through-pores with a pore size of 25 μm or more at a rate of 5 pores/mm 2 or more.

15 . A fuel cell comprising a gas diffusion electrode substrate as set forth in claim 6 .

Assignees

• Toray Industries

Inventors

• Sode Katsuya
• Chida Takashi
• Sugahara Toru
• Wakatabe Michio
• Hashimoto Masaru
• Sunahara Tetsuya
• Umezaki Yuya

Classifications

• H01M8/0245

  in the form of layered or coated products · CPC title

• H01M4/96

  Carbon-based electrodes · CPC title

• H01M4/8807 Primary

  Gas diffusion layers · CPC title

• H01M4/88

  Processes of manufacture · CPC title

• H01M8/1004

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