Catalyst electrode layer, membrane-electrode assembly, and fuel cell

Patent metadata

Field	Value
Publication number	US-2016118670-A1
Application number	US-201514887377-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Oct 24, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A catalyst electrode layer is configured to be disposed in contact with an electrolyte membrane of a fuel cell. A content of Fe per unit area of the catalyst electrode layer is equal to or larger than 0 μg/cm 2 and equal to or smaller than 0.14 μg/cm 2 , and a water absorption rate of the catalyst electrode layer is equal to or higher than 11% and equal to or lower than 30%.

First claim

What is claimed is:

1 . A catalyst electrode layer configured to be disposed in contact with an electrolyte membrane of a fuel cell, wherein:
a content of Fe per unit area of the catalyst electrode layer is equal to or larger than 0 μg/cm 2 and equal to or smaller than 0.14 μg/cm 2 , and a water absorption rate of the catalyst electrode layer is equal to or higher than 11% and equal to or lower than 30%; and the water absorption rate satisfies a relationship of the water absorption rate=(Q3−Q1)/Q1×100−(Q2−Q1)/Q1×100, where Q1 is a weight of the catalyst electrode layer after the catalyst electrode layer is dried for 1 hour under an environment in which a temperature is 100° C. and a relative humidity is 0%, after a fuel cell including the catalyst electrode layer is maintained for 100 hours under a condition that a cell temperature is 60° C., the relative humidity is 40%, and a generated voltage is 0.5 V, Q2 is a weight of the catalyst electrode layer after the catalyst electrode layer is further maintained for 1 hour under an environment in which the temperature is 70° C. and the relative humidity is 15%, and Q3 is a weight of the catalyst electrode layer after the catalyst electrode layer is further maintained for 1 hour under an environment in which the temperature is 70° C. and the relative humidity is 90%.

2 . The catalyst electrode layer according to claim 1 , comprising catalyst metal;
a catalyst support that supports the catalyst metal; and an ionomer, wherein the water absorption rate varies depending on a kind of the ionomer, a weight percent of the ionomer in the catalyst electrode layer, a kind of the catalyst support, a weight percent of the catalyst support in the catalyst electrode layer, and a structure of the catalyst electrode layer.

3 . A membrane-electrode assembly comprising:
an electrolyte membrane; and the catalyst electrode layer according to claim 1 , the catalyst electrode layer being provided on at least one of surfaces of the electrolyte membrane.

4 . A fuel cell comprising
the membrane-electrode assembly according to claim 3 .

Assignees

• Toyota Motor Co Ltd

Inventors

• Mizutani Nobuaki
• Yoshikawa Hiroo
• Nishida Tsunemasa

Classifications

• H01M8/1004 Primary

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

• H01M4/9041

  Metals or alloys (H01M4/92 takes precedence) · CPC title

• H01M4/8663 Primary

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

• H01M4/9075

  Catalytic material supported on carriers, e.g. powder carriers (H01M4/8807, H01M4/881, H01M4/8814, H01M4/925 take precedence) · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title