US 11,990,625 B2
Electrode catalyst layer, membrane electrode assembly, and polymer electrolyte fuel cell
Yuki Takabayashi, Tokyo (JP); Kazuma Taniwaki, Tokyo (JP); Ayako Mimatsu, Tokyo (JP); and Hiroyuki Michi, Tokyo (JP)
Assigned to TOPPAN PRINTING CO., LTD., Tokyo (JP)
Filed by TOPPAN PRINTING CO., LTD., Tokyo (JP)
Filed on Jun. 25, 2021, as Appl. No. 17/358,393.
Application 17/358,393 is a continuation of application No. PCT/JP2019/051477, filed on Dec. 27, 2019.
Claims priority of application No. 2018-247691 (JP), filed on Dec. 28, 2018; application No. 2019-007059 (JP), filed on Jan. 18, 2019; application No. 2019-077905 (JP), filed on Apr. 16, 2019; and application No. 2019-172731 (JP), filed on Sep. 24, 2019.
Prior Publication US 2021/0320302 A1, Oct. 14, 2021
Int. Cl. H01M 4/86 (2006.01); H01M 8/1004 (2016.01)
CPC H01M 4/8626 (2013.01) [H01M 8/1004 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An electrode catalyst layer configured to be bonded to a polymer electrolyte membrane in a polymer electrolyte fuel cell, the electrode catalyst layer, comprising:
a catalyst material;
a conductive carrier, which supports the catalyst material;
a polymer electrolyte; and
a fibrous material, wherein
the electrode catalyst layer includes a three-dimensional network of a flow path,
the flow path includes a plurality of terminal points and a plurality of branches, and each of the branches is an elongated hole connecting a pair of the terminal points,
the branches include a bifurcated branch, one of the pair of the terminal points of the bifurcated branch is connected to another of the branches, and
a number of the branches per unit volume of the electrode catalyst layer is 8500 or more and 13000 or less, and the unit volume is defined as 3.9 μm×3.9 μm×4.4 μm, and
wherein the electrode catalyst layer includes a first surface, a second surface which is a surface facing away from the first surface, and a plurality of through passages which extend from the first surface to the second surface,
a value obtained by dividing a length of each of the through passages by a thickness of the electrode catalyst layer is a tortuosity, and
in a histogram of the tortuosity with a class width of 0.01, a mode value is 1.8 or more and 2.8 or less.