Porous layer and manufacturing method of the same (as amended)

Patent metadata

Field	Value
Publication number	US-2016056480-A1
Application number	US-201314780565-A
Country	US
Kind code	A1
Filing date	Nov 29, 2013
Priority date	Apr 10, 2013
Publication date	Feb 25, 2016
Grant date	—

Abstract

A manufacturing method of porous layer comprises: drying a mixed solution containing conductive carbon powder and water-repellent resin powder by a spray-drying method, so as to produce a powdery substance including the conductive carbon powder coated with the water-repellent resin powder; and producing the porous layer from the powdery substance. Water-vapor permeability of the porous layer measured in conformity with the Japanese Industrial Standard ES-Z-0208 is 10000 to 25000 g/m 2 ·24 h under conditions of temperature of 40° C. and relative humidity of 90% RH.

First claim

1 . A manufacturing method of porous layer that produces a porous layer stacked between a catalyst layer and a gas diffusion layer in a membrane electrode assembly of a fuel cell, the manufacturing method comprising:
(a) process of drying a mixed solution containing conductive carbon powder and water-repellent resin powder by a spray-drying method, so as to produce a powdery substance including the conductive carbon powder coated with the water-repellent resin powder; and (b) process of producing the porous layer from the powdery substance produced by the process (a), such that water-vapor permeability of the porous layer measured in conformity with the Japanese Industrial Standard JIS-Z-0208 is 10000 to 25000 g/m 2 ·24 h under conditions of temperature of 40° C. and relative humidity of 90% RH.

2 . The manufacturing method of porous layer according to claim 1 , wherein the process (b) produces the porous layer having thickness of 50 to 150 μm from the powdery substance produced by the process (a).

3 . The manufacturing method of porous layer according to claim 1 , wherein the process (b) includes:
a process of preparing a paste from the powdery substance produced by the process (a); a process of molding the paste to a thin plate-like sheet; and a process of firing the sheet to produce the porous layer.

4 . The manufacturing method of porous layer according to claim 1 , wherein the water-repellent resin powder includes polytetrafluoroethylene (PTFE) powder.

5 . A porous layer stacked between a catalyst layer and a gas diffusion layer in a membrane electrode assembly of a fuel cell, wherein:
the porous layer is produced from a powdery substance that is obtained by drying a mixed solution containing conductive carbon powder and water-repellent resin powder by a spray-drying method; and water-vapor permeability of the porous layer measured in conformity with the Japanese Industrial Standard JIS-Z-0208 is 10000 to 25000 g/m 2 ·24 h under conditions of temperature of 40° C. and relative humidity of 90% RH.

6 . (canceled)

Assignees

• Toyota Motor Co Ltd

Inventors

• Hori Yoshihiro

Classifications

• Y02P70/50

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

• H01M8/1004 Primary

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

• H01M8/0234

  Carbonaceous material · CPC title

• H01M8/0239 Primary

  Organic resins; Organic polymers · CPC title

• Y02E60/50

  Fuel cells · CPC title