Method for producing gas diffusion electrode substrate

Patent metadata

Field	Value
Publication number	US-2023128336-A1
Application number	US-202117914015-A
Country	US
Kind code	A1
Filing date	Mar 18, 2021
Priority date	Mar 30, 2020
Publication date	Apr 27, 2023
Grant date	—

Abstract

The objective of the present invention is to provide a method which is for producing a gas diffusion electrode substrate having a high conductivity and a chemical resistance, and by which an increase in production cost can be suppressed. The present invention is a method for producing a gas diffusion electrode substrate in which a microporous layer is formed in a conductive porous body formed by bonding carbon fibers to each other by means of a cured product of a binder resin, the method having, in the following order: a binder resin impregnation step in which a carbon fiber structure is impregnated with a binder resin composition to obtain a pre-impregnated body; a coating step in which the surface of the pre-impregnated body is coated with a microporous layer coating solution; and a heat treatment step in which the pre-impregnated body that has been subjected to the coating step is heat-treated at a temperature of at least 200° C., wherein the binder resin composition is a liquid composition including a binder resin and a carbon powder, the binder resin being a thermosetting resin, and the method does not have a step for heat-treating the pre-impregnated body at a temperature of at least 200° C., between the binder resin impregnation step and the heat treatment step.

First claim

1 . A method for producing a gas diffusion electrode substrate in which a microporous layer is formed on an electrically conductive porous body obtained by binding carbon fibers to each other with a cured product of a binder resin, the method comprising, in order:
a binder resin impregnation step of impregnating a carbon fiber structure with a binder resin composition to obtain a prepreg; a coating step of coating a surface of the prepreg with a microporous layer coating liquid; and a heat treatment step of heat-treating the prepreg after the coating step at a temperature of 200° C. or higher, wherein the binder resin composition is a liquid composition including a binder resin and a carbon powder, and the binder resin is a thermosetting resin, and the method not comprising a step of heat-treating the prepreg at a temperature of 200° C. or higher between the binder resin impregnation step and the heat treatment step.

2 . The method for producing a gas diffusion electrode substrate according to claim 1 , wherein in the binder resin impregnation step, the carbon fiber structure is impregnated with the binder resin composition so that an amount of the binder resin is 10 to 400 parts by mass based on 100 parts by mass of carbon fibers in the prepreg.

3 . The method for producing a gas diffusion electrode substrate according to claim 1 , wherein the carbon fiber structure is a carbon fiber papermaking material.

4 . The method for producing a gas diffusion electrode substrate according to claim 1 , wherein the carbon powder is graphite.

5 . The method for producing a gas diffusion electrode substrate according to claim 4 , wherein in the binder resin composition, an amount of the graphite is 150 to 400 parts by mass based on 100 parts by mass of the binder resin.

6 . The method for producing a gas diffusion electrode substrate according to claim 1 , wherein the carbon powder is a nanocarbon material selected from carbon black, a carbon nanotube, or a carbon nanofiber.

7 . The method for producing a gas diffusion electrode substrate according to claim 6 , wherein in the binder resin composition, an amount of the nanocarbon material is 30 to 200 parts by mass based on 100 parts by mass of the binder resin.

8 . The method for producing a gas diffusion electrode substrate according to claim 1 , comprising a water repellent addition step of adding a water repellent including a fluororesin to the prepreg before the coating step.

9 . The method for producing a gas diffusion electrode substrate according to claim 1 , comprising a drying step of drying the prepreg after the coating step at a temperature of 80 to 180° C. before the heat treatment step.

10 . The method for producing a gas diffusion electrode substrate according to claim 1 , wherein the heat treatment temperature in the heat treatment step is 200 to 400° C.

Assignees

• Toray Industries

Inventors

• Otake Hiroaki
• Utsunomiya Masamichi
• Watanabe Fumitaka

Classifications

• H01M4/8807 Primary

  Gas diffusion layers · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/8605

  Porous electrodes · CPC title

• H01M4/8882

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

• H01M4/96

  Carbon-based electrodes · CPC title