Fuel cell module, fuel cell stack, and manufacturing method of fuel cell module
A fuel cell module that suppress deterioration of an electrolyte membrane is provided. The fuel cell module includes a membrane-electrode assembly (MEA) including a polymer electrolyte membrane, an anode catalyst layer disposed on a surface of the membrane, a cathode catalyst layer disposed on the other surface of the membrane, and a pair of gas diffusion layers laminated on the anode catalyst layer and the cathode catalyst layer respectively, a pair of separators sandwiching the MEA; and a sealing member sealing the MEA and each of the pair of separators together. One gas diffusion layer and the sealing member overlaps in a thickness direction within a region including a center-side edge of the sealing member, and the one gas diffusion layer is notched through in the thickness direction at a part of a portion corresponding to the region.
1. A fuel cell module comprising:
a membrane-electrode assembly including
a polymer electrolyte membrane,
an anode catalyst layer disposed on a first main surface of the polymer electrolyte membrane,
a cathode catalyst layer disposed on a second main surface of the polymer electrolyte membrane, and
a pair of gas diffusion layers, one of which is laminated on the anode catalyst layer and the other of which is laminated on the cathode catalyst layer;
a pair of separators sandwiching the membrane-electrode assembly therebetween; and
a sealing member bonding and sealing the membrane-electrode assembly and each of the pair of separators together,
wherein an overlapping region is provided in which one gas diffusion layer of the pair of gas diffusion layers and the sealing member overlap each other in a thickness direction, the overlapping region including a center-side edge of the sealing member,
the one gas diffusion layer has a first surface and a second surface, the first and second surfaces being disposed on opposite sides of the one gas diffusion layer with respect to the thickness direction, and the one gas diffusion layer is notched so as to penetrate between the first surface and the second surface in the thickness direction at a portion of the one gas diffusion layer within the overlapping region, and
wherein the portion of the one gas diffusion layer within the overlapping region includes a serrated portion formed in a saw teeth shape in plan view.
2. The fuel cell module according to claim 1 , wherein the portion of the one gas diffusion layer within the overlapping region includes a plurality of through-holes passing through in the thickness direction, and respective sizes of the through-holes are larger than a thickness of the one gas diffusion layer.
3. The fuel cell module according to claim 1 , wherein
the pair of gas diffusion layers are an anode gas diffusion layer laminated on the anode catalyst layer and a cathode gas diffusion layer laminated on the cathode catalyst layer,
the pair of separators are an anode separator arranged toward the anode gas diffusion layer of the membrane-electrode assembly and a cathode separator arranged toward the cathode gas diffusion layer of the membrane-electrode assembly, the cathode separator and the anode separator in pairs sandwiching the membrane-electrode assembly therebetween, and
the sealing member includes:
an anode sealing member having an opening portion, the anode sealing member bonding and sealing the membrane-electrode assembly and the anode separator together; and
a cathode sealing member having an opening portion, the cathode sealing member bonding and sealing the membrane-electrode assembly and the cathode separator together, wherein
when viewed from a direction perpendicular to the first main surface, the anode gas diffusion layer has an anode-side inner region overlapping the anode sealing member at a region including an edge toward the opening portion of the anode sealing member,
when viewed from the direction perpendicular to the first main surface, the cathode gas diffusion layer has a cathode-side inner region overlapping the cathode sealing member at a region including an edge toward the opening portion of the cathode sealing member,
the anode gas diffusion layer has a void passing through in the thickness direction of the anode gas diffusion layer in at least a part including the anode-side inner region,
the cathode gas diffusion layer has a void passing through in the thickness direction of the cathode gas diffusion layer in at least a part including the cathode-side inner region, and
when viewed from the direction perpendicular to the first main surface, the anode-side inner region and the cathode-side inner region do not overlap.
4. The fuel cell module according to claim 3 , wherein when viewed from the direction perpendicular to the first main surface, the anode-side inner region has an outer portion lying outside of the cathode-side inner region and an inner portion lying inside of the cathode-side inner region.
5. The fuel cell module according to claim 3 , wherein at least one of the void formed in the anode gas diffusion layer and the void formed in the cathode gas diffusion layer includes a plurality of through-holes.
6. The fuel cell module according to claim 3 , wherein at least one of the void formed in the anode gas diffusion layer and the void formed in the cathode gas diffusion layer is formed by a saw-toothed notch when viewed from the direction perpendicular to the first main surface.
7. A fuel cell stack comprising a plurality of fuel cell modules connected in series, each fuel cell module of the plurality of fuel cell modules being the fuel cell module according to claim 1 .