US 12,095,099 B2
Catalyst layer and method for producing the same
Shinsuke Hirono, Sunto-gun (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP)
Filed by TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP)
Filed on Mar. 24, 2022, as Appl. No. 17/656,417.
Claims priority of application No. 2021-050888 (JP), filed on Mar. 25, 2021.
Prior Publication US 2022/0311016 A1, Sep. 29, 2022
Int. Cl. H01M 4/90 (2006.01); H01M 4/86 (2006.01); H01M 4/88 (2006.01); H01M 4/92 (2006.01)
CPC H01M 4/9083 (2013.01) [H01M 4/861 (2013.01); H01M 4/8642 (2013.01); H01M 4/8652 (2013.01); H01M 4/8657 (2013.01); H01M 4/8814 (2013.01); H01M 4/8828 (2013.01); H01M 4/8882 (2013.01); H01M 4/926 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A catalyst layer for a fuel cell,
wherein the fuel cell comprises an electrolyte membrane, the catalyst layer and a gas diffusion layer in this order;
wherein the catalyst layer comprises a catalyst-supporting carbon and an ionomer;
wherein, in a particle size distribution obtained by the laser diffraction/scattering method, the catalyst-supporting carbon has at least two aggregate particle size peaks at less than 1 μm and at 1 μm or more;
wherein, when a thickness of the catalyst layer is divided into three equal parts, the catalyst layer has a first region on a gas diffusion layer side, a second region in a middle part, and a third region on an electrolyte membrane side;
wherein a void ratio VG of the first region is 43% or more and 44% or less;
wherein a void ratio VM of the third region is 34% or more and 35% or less;
wherein a void ratio VC of the second region is higher than the void ratio VM and lower than the void ratio VG;
wherein a mass ratio (I/C) of the ionomer to the catalyst-supporting carbon of the third region is 1.10 or more and 1.30 or less; and
wherein a mass ratio (I/C) of the ionomer to the catalyst-supporting carbon of the second region is 0.95 or more and 1.00 or less.