Carbon sheet, gas diffusion electrode substrate, wound body, and fuel cell (as amended)

Patent metadata

Field	Value
Publication number	US-2018301712-A1
Application number	US-201615767503-A
Country	US
Kind code	A1
Filing date	Oct 11, 2016
Priority date	Oct 22, 2015
Publication date	Oct 18, 2018
Grant date	—

Abstract

The purpose of the present invention is to provide a carbon sheet that is suitably employed in a gas-diffusion-electrode substrate that has excellent flooding resistance and with which it is possible to suppress internal peeling of the carbon sheet. In order to achieve the aforementioned purpose, the present invention has the following configuration. Specifically, provided is a porous carbon sheet containing carbon fibers and a binder, wherein, in a section between a surface on one side of the carbon sheet and a surface on the other side thereof, when layers obtained by dividing, under compression, the carbon sheet into six equal parts in the thickness direction are, assumed to be layer 1 , layer 2 , layer 3 , layer 4 , layer 5 , and layer 6 , in order starting from the layer including the surface on the one side to the layer including the surface on the other side, the layer in which the packing ratio under compression is the greatest is layer 2 , and the relationships of the packing ratios under compression among layer 2 , layer 3 , layer 4 , layer 5 , and layer 6 are such that layer 2 has the greatest packing ratio, and layer 3 has the second-greatest packing ratio.

First claim

1 . A porous carbon sheet comprising a carbon fiber and a binding material, wherein
when layers obtained by dividing the carbon sheet in a thickness direction into six equal parts under compression within a section extending from one surface to the other surface include a layer 1 , a layer 2 , a layer 3 , a layer 4 , a layer 5 and a layer 6 in this order from the layer including one surface to the layer including the other surface, a layer having the largest filling rate under compression is the layer 2 , and the filling rates of the layer 2 , the layer 3 , the layer 4 , the layer 5 and the layer 6 under compression satisfy the relationship of: the layer 2 has the largest filling rate, and the layer 3 has the second largest filling rate.

2 . The carbon sheet according to claim 1 , wherein the filling rates of the layer 2 , the layer 3 , the layer 4 , the layer 5 and the layer 6 under compression satisfy the relationship of: filling rate of layer 2 >filling rate of layer 3 >filling rate of layer 4 >filling rate of layer 5 >filling rate of layer 6 .

3 . The carbon sheet according to claim 1 , wherein the filling rate of the layer 2 is 10% or more and 50% or less.

4 . The carbon sheet according to claim 1 , having a difference in filling rate between the layer 2 and the layer 1 (filling rate of layer 2 −filling rate of layer 1 ) of 5% or more.

5 . The carbon sheet according to claim 1 , having differences in filling rate between the layer 2 and each of the layers 4 to 6 (filling rate of layer 2 −each of filling rates of layers 4 to 6 ) of each 5% or more.

6 . The carbon sheet according to claim 1 , having a difference in filling rate between the layer 2 and the layer 3 (filling rate of layer 2 −filling rate of layer 3 ) of 3% or more.

7 . The carbon sheet according to claim 1 , wherein when a surface included in the layer 6 is a surface 6 , the surface 6 has a surface coverage of 7% or less.

8 . A gas diffusion electrode substrate, wherein when a surface included in the layer 1 is a surface 1 , the gas diffusion electrode substrate has a microporous layer on the surface 1 of the carbon sheet according to claim 1 .

9 . A wound body, which is the carbon sheet according to claim 1 wound up.

10 . A wound body, which is the gas diffusion electrode substrate according to claim 8 wound up.

11 . A fuel cell comprising the gas diffusion electrode substrate according to claim 8 .

Assignees

• Toray Industries

Inventors

• Sode Katsuya
• Sugahara Toru
• Ando Takashi

Classifications

• H01M8/0234 Primary

  Carbonaceous material · CPC title

• H01M4/8605

  Porous electrodes · CPC title

• H01M4/8657

  layered · CPC title

• H01M4/96

  Carbon-based electrodes · CPC title

• H01M8/0245

  in the form of layered or coated products · CPC title