JP2016058206A - Fuel battery cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery cell which enables the chemical degradation of an electrolyte film owing to generation of hydroxy radicals at ends of the electrolyte film.SOLUTION: A fuel battery cell 1 comprises an electrolyte film 10, an anode catalyst layer 21 and a cathode catalyst layer 22, an anode gas diffusion layer 31 and a cathode gas diffusion layer 32, and a first separator 41 and a second separator 42. The first separator 41 (second separator 42) has a first protrusion 411 (second protrusion 421). The first protrusion 411 (second protrusion 421) has a first end protrusion 411a (second end protrusion 421a) provided to extend in the vicinity of an end of the first separator 41 (second separator 42), and a first inside protrusion 411b (second inside protrusion 421b) provided to extend thereinside. The first end protrusion 411a (second end protrusion 421a) is shorter than the first inside protrusion 411b (second inside protrusion 421b) in its distance from its tip to the electrolyte film 10 in a laminating direction.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to a fuel battery cell.

  In recent years, fuel cells that generate electricity by electrochemical reaction of hydrogen and oxygen are attracting attention as new power sources for automobiles. A fuel cell is preferred in terms of high power generation efficiency because it directly obtains electricity through an electrochemical reaction. In addition, since the fuel cell generates only water during power generation, it is considered preferable from the viewpoint of environmental impact.

  For example, a polymer electrolyte fuel cell has a stack structure in which several tens to several hundreds of fuel cells are stacked. Each fuel cell is configured by sandwiching a membrane electrode structure (MEA) between a pair of separators. The membrane electrode structure is composed of an anode electrode (cathode) and a cathode electrode (anode), and an electrolyte membrane sandwiched between these electrodes. Both electrodes are a catalyst layer in contact with the electrolyte membrane, and a gas in contact with the catalyst layer. A diffusion layer (see, for example, Patent Document 1). The separator has a fuel gas channel formed on one surface thereof and an oxidant gas channel formed on the other surface thereof.

  In the polymer electrolyte fuel cell having the above-described configuration, hydrogen as fuel gas is supplied to the anode electrode via the fuel gas flow path. In addition, air as an oxidant gas is supplied to the cathode electrode via the oxidant gas flow path. Then, the hydrogen supplied to the anode electrode is protonated on the catalyst layer, and the generated proton moves to the cathode electrode through the electrolyte membrane. At this time, electrons generated together with protons are taken out to an external circuit and used as electric energy.

JP 2002-270202 A

  By the way, the dimensions (ranges) in plan view of the electrolyte membrane, the catalyst layer, the gas diffusion layer, and the gas flow path (fuel gas flow path and oxidant gas flow path) in the fuel cell are generally different. 2A and 2B exemplify the relationship of the size (range) of the electrolyte membrane, the catalyst layer, the gas diffusion layer, and the gas flow path in the plan view of the fuel cell. FIG. 2A is a cross-sectional view of a conventional fuel cell 1P. FIG. 2B is a cross-sectional view of a conventional fuel cell 1P, and is a view for explaining the operation of the conventional fuel cell. The fuel cell 1P includes a membrane electrode structure 50P, a pair of separators 41P and 42P that sandwich the membrane electrode structure 50P, and seal members 61P and 62P. The membrane electrode structure 50P is configured by stacking an anode electrode 51P, a cathode electrode 52P, and an electrolyte membrane 10P.

  For example, if the range of the catalyst layers 21P and 22P is equal to the range of the gas flow paths 413P and 423P as shown in FIG. 2A, the amount of catalyst used can be suppressed without reducing the power generation efficiency of the fuel cell. In order to maintain the structure of the membrane electrode structure 50P, the range of the electrolyte membrane 10P and the gas diffusion layers 31P and 32P is usually larger than the range of the catalyst layers 21P and 22P as shown in FIG. 2A. .

  However, when the structure of the fuel cell 1P is configured as shown in FIG. 2A, there is a portion that directly contacts the electrolyte membrane 10P without the catalyst layers 21P and 22P in the vicinity of the end portions of the gas diffusion layers 31P and 32P. To do. In the fuel cell 1P having such a structure, as shown in FIG. 2B, the fuel gas (hydrogen) and the oxidant gas (oxygen) diffused near the end portions of the gas diffusion layers 31P and 32P are subjected to an electrochemical reaction. Without being diffused, it is diffused and mixed in the end portion of the electrolyte membrane 10P. The gas mixed in the electrolyte membrane 10P reacts with the electrode catalyst to generate hydrogen peroxide. Furthermore, hydroxyl radicals are generated from hydrogen peroxide. Hydroxyl radicals shorten the life of the fuel cell 1P by chemically degrading the electrolyte membrane 10P.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel cell that can suppress chemical deterioration of the electrolyte membrane due to the generation of hydroxy radicals at the end of the electrolyte membrane. To do.

  In order to achieve the above object, the present invention provides an electrolyte membrane (for example, an electrolyte membrane 10 described later) and a pair of catalyst layers (for example, an anode catalyst layer 21 and a cathode catalyst described later) laminated on both surfaces of the electrolyte membrane. Layer 22), a pair of gas diffusion layers (for example, an anode gas diffusion layer 31 and a cathode gas diffusion layer 32 described later) stacked on the outer surfaces of the pair of catalyst layers, and the outer surfaces of the pair of gas diffusion layers A pair of separators (for example, a first separator 41 and a second separator 42, which will be described later), the pair of separators projecting toward the gas diffusion layer and extending at the tip of the gas It has a plurality of convex portions (for example, a first convex portion 411 and a second convex portion 421 described later) that press the diffusion layer, and the convex portion is an end convex portion that extends in the vicinity of the end portion of the separator. (For example, see below A first end convex portion 411a and a second end convex portion 421a), and an inner convex portion (for example, a first inner convex portion 411b described later) extending inward in the planar direction of the separator from the end convex portion. And a second inner convex portion 421b), and the end convex portion has a shorter distance in the stacking direction from the tip to the electrolyte membrane than the inner convex portion (for example, a fuel cell described later) Cell 1) is provided.

In the present invention, the distance in the stacking direction from the tip of the end projection to the electrolyte membrane is shorter than the distance in the stacking direction from the tip of the inner projection to the electrolyte membrane.
As a result, the gas diffusion layer is more strongly sandwiched by the separator from the stacking direction near the end than the inner side in the plane direction, so that it is difficult for gas to diffuse from the vicinity of the end of the gas diffusion layer into the electrolyte membrane. The fuel cell according to the present invention makes it difficult for the fuel gas (hydrogen) and the oxidant gas (oxygen) to diffuse into the electrolyte membrane, thereby suppressing the generation of hydroxyl radicals due to the reaction of these gases. it can. Therefore, the fuel battery cell according to the present invention can suppress chemical deterioration of the electrolyte membrane.

  The gas diffusion layer has a larger planar dimension than the catalyst layer on which the gas diffusion layer is laminated, and the end convex portion presses the gas diffusion layer on the outer side in the planar direction than the catalyst layer. It is characterized by that.

  In the vicinity of the end portion of the gas diffusion layer, when there is a portion that contacts the electrolyte membrane without passing through the catalyst layer, the gas easily diffuses into the electrolyte membrane. In this invention, in such a fuel cell, the effect of suppressing the chemical deterioration of the electrolyte membrane can be more significantly exhibited by pressing the portion of the gas diffusion layer that directly contacts the electrolyte membrane with the end convex portion. .

  Further, it is preferable that the end convex portion has a shorter distance in the stacking direction from the tip to the electrolyte membrane than the inner convex portion over the entire extending direction.

  This makes it difficult for the fuel gas (hydrogen) and the oxidant gas (oxygen) to diffuse to the end of the electrolyte membrane over the entire extending direction of the end convex portion, so that these gases react to react with hydroxyl. Generation of radicals can be suppressed more strongly. Therefore, the fuel battery cell according to the present invention can suppress the chemical deterioration of the electrolyte membrane more strongly.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel battery cell which can suppress the chemical degradation of the electrolyte membrane by a hydroxyl radical producing | generating in the edge part of an electrolyte membrane can be provided.

It is sectional drawing of the fuel battery cell which concerns on one Embodiment of this invention. It is sectional drawing of the fuel battery cell which concerns on the said embodiment, and is a figure for demonstrating the effect | action of the fuel battery cell which concerns on the said embodiment. It is sectional drawing of the conventional fuel cell. It is sectional drawing of the conventional fuel cell, and is a figure for demonstrating the effect | action of the conventional fuel cell.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1A and 1B are cross-sectional views of a fuel cell 1 according to an embodiment of the present invention. For example, a plurality of fuel cells 1 are stacked in the vertical direction with the electrode surface horizontal, thereby constituting a fuel cell stack. Since a predetermined tightening load is applied to the stacked fuel cells 1, a predetermined surface pressure is applied to the electrode surface of the fuel cells 1.

  The fuel cell 1 includes an electrolyte membrane 10, a pair of anode catalyst layers 21 and cathode catalyst layers 22, a pair of anode gas diffusion layers 31 and cathode gas diffusion layers 32, and a pair of first separators 41 and second separators 42. And an inner seal member 61 and an outer seal member 62.

  The electrolyte membrane 10 is a solid polymer electrolyte membrane composed of, for example, perfluorosulfonic acid. As this solid polymer electrolyte membrane, a commercially available product can be used. For example, “Nafion” manufactured by DuPont can be used.

  The pair of anode catalyst layer 21 and cathode catalyst layer 22 are laminated on both surfaces of the electrolyte membrane 10. The anode catalyst layer 21 and the cathode catalyst layer 22 include catalyst particles made of porous carbon particles having a platinum alloy supported on the surface, and the above-described polymer electrolyte. The anode catalyst layer 21 and the cathode catalyst layer 22 have smaller planar dimensions than the electrolyte membrane 10. The anode catalyst layer 21 and the cathode catalyst layer 22 have the same planar dimensions.

The pair of anode gas diffusion layer 31 and cathode gas diffusion layer 32 are laminated on the outer surfaces of the anode catalyst layer 21 and the cathode catalyst layer 22, respectively. The anode gas diffusion layer 31 and the cathode gas diffusion layer 32 are made of carbon paper, carbon cloth, or the like.
The anode gas diffusion layer 31 has a smaller planar dimension than the electrolyte membrane 10 and a larger planar dimension than the anode catalyst layer 21.
The cathode gas diffusion layer 32 has the same planar dimension as the electrolyte membrane 10 and has a larger planar dimension than the anode catalyst layer 21.

  As described above, the anode catalyst layer 21 and the anode gas diffusion layer 31 are laminated to constitute the anode electrode 51, and the cathode catalyst layer 22 and the cathode gas diffusion layer 32 are laminated to constitute the cathode electrode 52. To do. These electrodes are laminated on the electrolyte membrane 10 such that the anode catalyst layer 21 and the cathode catalyst layer 22 are in contact with the electrolyte membrane 10 and face the anode gas diffusion layer 31 and the cathode gas diffusion layer 32 outward. The electrolyte membrane 10, the anode electrode 51, and the cathode electrode 52 constitute a membrane electrode structure (MEA) 50 by being laminated.

  The pair of first separator 41 and second separator 42 are stacked on the outer surfaces of the anode gas diffusion layer 31 and the cathode gas diffusion layer 32, respectively, and sandwich the membrane electrode structure 50 therebetween. The first separator 41 and the second separator 42 are metal separators obtained by forming a metal thin plate into a corrugated plate by press molding.

The first separator 41 has a plurality of first protrusions 411 that protrude and extend toward the anode gas diffusion layer 31 side and whose tips press the anode gas diffusion layer 31. The tip of the first convex portion 411 is a flat surface and presses the anode gas diffusion layer 31 by the tightening load of the fuel cell stack.
The first convex portion 411 extends in the vicinity of the end portion of the first separator 41, and extends inward in the planar direction of the first separator 41 from the first end convex portion 411a. First inner convex portion 411b. The first end protrusion 411 a presses the end of the anode gas diffusion layer 31. More specifically, the first end convex portion 411 a presses the anode gas diffusion layer 31 outside the anode catalyst layer 21 in the planar direction.

The first end convex portion 411a is shorter in the stacking direction from the tip to the electrolyte membrane 10 than the first inner convex portion 411b. In other words, the distance _{D 11} of the stacking direction between the tip and the electrolyte membrane 10 of the first end convex portion 411a is shorter than the stacking direction of the distance _{D 12} between the electrolyte membrane 10 and the distal end of the first inner protrusion 411b. In addition, the distance in the lamination direction from the front-end | tip to the electrolyte membrane 10 is shorter than the 1st inner side convex part 411b of the 1st edge part convex part 411a over the whole extending direction.

  Moreover, the 1st separator 41 has the 1st recessed part 412 formed between the adjacent 1st edge part convex part 411a and the 1st inner side convex part 411b, or between the adjacent 1st inner side convex parts 411b. Between the anode gas diffusion layer 31 and the first separator 41, a fuel gas channel 413 is formed by the first recess 412. Hydrogen as a fuel gas of the fuel cell flows through the fuel gas flow path 413.

The second separator 42 has a plurality of second protrusions 421 that protrude and extend toward the cathode gas diffusion layer 32 side and whose tips press the cathode gas diffusion layer 32. The tip of the second convex portion 421 is a flat surface and presses the cathode gas diffusion layer 32 by the tightening load of the fuel cell stack.
The second convex portion 421 extends in the planar direction of the second separator 42 from the second end convex portion 421a extending in the vicinity of the end portion of the second separator 42, and the second end convex portion 421a. Second inner convex portion 421b. The second end convex portion 421a faces the first end convex portion 411a via the membrane electrode structure 50 and presses the end portion of the cathode gas diffusion layer 32. More specifically, the second end convex portion 421a presses the cathode gas diffusion layer 32 outside the cathode catalyst layer 22 in the planar direction. The second inner convex portion 421b faces the first inner convex portion 411b with the membrane electrode structure 50 interposed therebetween.

The second end convex portion 421a has a shorter distance in the stacking direction from the tip to the electrolyte membrane 10 than the second inner convex portion 421b. In other words, the distance _{D 11} of the stacking direction between the tip and the electrolyte membrane 10 of the second end protrusion 421a is shorter than the stacking direction of the distance _{D 12} between the tip and the electrolyte membrane 10 of the second inner protrusion 421b. The second end convex portion 421a has a shorter distance in the stacking direction from the tip to the electrolyte membrane 10 than the second inner convex portion 421b over the entire extending direction.

  Further, the second separator 42 has a second recess 422 formed between the adjacent second end protrusions 421a and the second inner protrusions 421b or between the adjacent second inner protrusions 421b. Between the cathode gas diffusion layer 32 and the second separator 42, an oxidant gas flow path 423 is formed by the second recess 422. Air containing oxygen as an oxidant gas for the fuel cell flows through the oxidant gas flow path 423.

  The inner seal member 61 is disposed on the outer periphery of the fuel cell 1 and is sandwiched between the first separator 41 and the electrolyte membrane 10. The inner seal member 61 seals the space between the first separator 41 and the electrolyte membrane 10.

  The outer seal member 62 is disposed on the outer periphery of the fuel cell 1 and is sandwiched between the second separator 42 and the electrolyte membrane 10. The outer seal member 62 is disposed outside the inner seal member 61. The outer seal member 62 defines the distance between the first separator 41 and the second separator 42 by the thickness in the stacking direction. The outer seal member 62 and the inner seal member 61 seal the space between the second separator 42 and the electrolyte membrane 10.

The fuel cell 1 of the present embodiment having the above configuration is manufactured, for example, as follows.
First, the membrane electrode structure 50 is produced. Specifically, an anode electrode ink and a cathode electrode ink are prepared by charging a binder solution into a mixture of an anode catalyst or a cathode catalyst and a solvent and mixing the mixture until a predetermined ink viscosity is obtained.
Next, the prepared electrode inks are coated on a PET sheet made of a PET film by screen printing to produce an anode electrode sheet and a cathode electrode sheet.
Next, the electrolyte membrane 10 (for example, “Nafion” manufactured by DuPont) is sandwiched between the electrode sheets and hot-pressed. Thereafter, the PET sheet is peeled off, whereby the anode catalyst layer 21 is formed on one surface of the electrolyte membrane 10 and the cathode catalyst layer 22 is formed on the other surface.

  Next, a slurry in which carbon black and PTFE (polytetrafluoroethylene) particles are uniformly dispersed is prepared. The prepared slurry is applied to carbon paper and dried to produce an anode gas diffusion layer 31 and a cathode gas diffusion layer 32 made of carbon paper and a base layer. The planar dimension of the cathode gas diffusion layer 32 is the same as that of the electrolyte membrane 10. The planar dimension of the anode gas diffusion layer 31 is larger than that of the anode catalyst layer 21 and smaller than that of the cathode gas diffusion layer 32 and the electrolyte membrane 10.

  Next, an anode gas diffusion layer 31 is disposed on one side of the electrolyte membrane 10 on which the anode catalyst layer 21 is formed, and a cathode gas diffusion layer 32 is disposed on the other side of the electrolyte membrane 10 on which the cathode catalyst layer 22 is formed. Place and hot press in this state. Thereby, the membrane electrode structure 50 is produced.

  Separately from the membrane electrode structure 50, the first separator 41 and the second separator 42 are produced. In the production of the first separator 41 and the second separator 42, a metal thin plate is formed into a corrugated plate by press molding. Specifically, a metal thin plate is formed by drawing with a conventionally known press forming apparatus to form a corrugated plate having irregularities. As the metal thin plate, for example, a steel plate, a stainless steel plate, an aluminum plate, or the like is used.

Next, the obtained membrane electrode structure 50 is sandwiched between the first separator 41 and the second separator 42 to obtain the fuel cell 1. When the membrane electrode structure 50 is sandwiched between the first separator 41 and the second separator 42, the inner seal member 61 and the outer seal member 62 are disposed on the outer periphery.
Thus, the fuel cell 1 according to the present embodiment is manufactured, and the fuel cell stack is manufactured by stacking the fuel cells.

The fuel cell stack including the fuel cell 1 according to the present embodiment having the above configuration operates as follows.
First, an oxidant gas is supplied to the fuel cell stack by an oxidant gas supply device (not shown). Then, the supplied oxidant gas flows through the oxidant gas flow path 423. As a result, the oxidant gas is supplied to the cathode electrode 52. Note that the oxidant gas also slightly flows through the space formed between the end portion of the cathode gas diffusion layer 32 and the outer seal member 62.
On the other hand, fuel gas is supplied to the fuel cell stack by a fuel gas supply device (not shown). Then, the supplied fuel gas flows through the fuel gas channel 413. As a result, the fuel gas is supplied to the anode electrode 51. Note that the fuel gas also slightly flows through the space formed between the end of the anode gas diffusion layer 31 and the inner seal member 61.

By the way, since the distance D ₁₁ (distance D ₂₁ ) is shorter than the distance D ₁₂ (distance D ₂₂ ), the anode gas diffusion layer 31 (cathode gas diffusion layer 32) is stronger in the vicinity of the end portion than in the plane direction. It is sandwiched from the stacking direction. As schematically shown in FIG. 1B, in the vicinity of the end of the anode gas diffusion layer 31 (cathode gas diffusion layer 32) strongly sandwiched from the stacking direction, the inside of the anode gas diffusion layer 31 and the anode gas diffusion layer 31 Gas hardly diffuses from the space formed between the end portion and the inner seal member 61. Similarly, gas diffuses in the vicinity of the end of the cathode gas diffusion layer 32 from the inside of the cathode gas diffusion layer 32 and from the space formed between the end of the cathode gas diffusion layer 32 and the outer seal member 62. It becomes difficult to do.

  In the membrane electrode structure 50, power generation is performed by an electrochemical reaction between the oxidant gas supplied to the cathode electrode 52 and the fuel gas supplied to the anode electrode 51. During power generation, water is generated on the cathode side along with the electrochemical reaction, and moves to the anode side via the electrolyte membrane 10. This reaction product water is discharged through each gas flow path.

According to this embodiment, the following effects are produced.
In the present embodiment, the distance D ₁₁ (distance D ₂₁ ) in the stacking direction from the tip of the first end convex portion 411a (second end convex portion 421a) to the electrolyte membrane 10 is defined as the first inner convex portion 411b (first). The distance D ₁₂ (distance D ₂₂ ) in the stacking direction from the tip of the 2 inner convex part 421b) to the electrolyte membrane 10 was made shorter.
As a result, the anode gas diffusion layer 31 (cathode gas diffusion layer 32) is more strongly sandwiched by the first separator 41 (second separator 42) in the vicinity of the end than the inner side in the plane direction. Gas hardly diffuses into the electrolyte membrane 10 from the vicinity of the end of the layer 31 (cathode gas diffusion layer 32) (FIG. 1B). In the fuel cell 1, it is difficult for the fuel gas (hydrogen) and the oxidant gas (oxygen) to diffuse into the electrolyte membrane 10, so that the generation of hydroxyl radicals due to the reaction of these gases can be suppressed. Therefore, the fuel battery cell 1 can suppress chemical deterioration of the electrolyte membrane 10.

In the present embodiment, the anode gas diffusion layer 31 (cathode gas diffusion layer 32) has a larger planar dimension than the anode catalyst layer 21 (cathode catalyst layer 22). Further, the first end convex portion 411a (second end convex portion 421a) forms the anode gas diffusion layer 31 (cathode gas diffusion layer 32) outside the anode catalyst layer 21 (cathode catalyst layer 22) in the planar direction. It was supposed to be pressed.
When there is a portion in contact with the electrolyte membrane 10 without passing through the anode catalyst layer 21 (cathode catalyst layer 22) in the vicinity of the end of the anode gas diffusion layer 31 (cathode gas diffusion layer 32), gas flows into the electrolyte membrane 10. It becomes easy to diffuse. In the present embodiment, in such a fuel cell 1, the portion of the anode gas diffusion layer 31 (cathode gas diffusion layer 32) that directly contacts the electrolyte membrane 10 is defined as the first end protrusion 411a (second end protrusion). By pressing at 421a), the effect of suppressing the chemical deterioration of the electrolyte membrane 10 can be exhibited more remarkably.

In the present embodiment, the distance D ₁₁ (distance D ₂₁ ) is changed from the distance D ₁₂ (distance D ₂₂ ) over the entire extending direction of the first end convex portion 411a (second end convex portion 421a). Also shortened.
Thereby, the fuel gas (hydrogen) and the oxidant gas (oxygen) are difficult to diffuse in the end portion of the electrolyte membrane 10 over the entire extending direction of the first end convex portion 411a (second end convex portion 421a). Therefore, the generation of hydroxyl radicals due to the reaction of these gases can be further suppressed. Therefore, the fuel battery cell 1 can suppress the chemical deterioration of the electrolyte membrane 10 more strongly.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
In the said embodiment, although the 1st separator 41 and the 2nd separator 42 shall be a metal separator, this invention is not limited to this. For example, the first separator 41 and the second separator 42 may be carbon separators manufactured by cutting a thin plate made of carbon.

DESCRIPTION OF SYMBOLS 1 ... Fuel cell 10 ... Electrolyte membrane 21 ... Anode catalyst layer (catalyst layer)
22 ... Cathode catalyst layer (catalyst layer)
31 ... Anode gas diffusion layer (diffusion layer)
32 ... Cathode gas diffusion layer (diffusion layer)
41 ... 1st separator (separator)
411 ... 1st convex part (convex part)
411a ... 1st edge part convex part (edge part convex part)
411b ... 1st inside convex part (inside convex part)
42. Second separator (separator)
421 ... 2nd convex part (convex part)
421a ... 2nd edge part convex part (edge part convex part)
421b ... 2nd inner side convex part (inner side convex part)

Claims (3)

An electrolyte membrane;
A pair of catalyst layers laminated on both sides of the electrolyte membrane;
A pair of gas diffusion layers laminated on the outer surfaces of the pair of catalyst layers;
A pair of separators laminated on the outer surface of the pair of gas diffusion layers,
The pair of separators have a plurality of protrusions that protrude and extend toward the gas diffusion layer side, and whose tips press the gas diffusion layer,
The convex portion includes an end convex portion extending in the vicinity of the end portion of the separator, and an inner convex portion extending inward in the planar direction of the separator from the end convex portion,
The end protrusion is a fuel cell having a shorter distance in the stacking direction from the tip to the electrolyte membrane than the inner protrusion. The gas diffusion layer has a larger planar dimension than the catalyst layer on which the gas diffusion layer is laminated,
The fuel cell according to claim 1, wherein the end convex portion presses the gas diffusion layer on the outer side in the planar direction than the catalyst layer.   The fuel cell according to claim 1, wherein the end convex portion has a shorter distance in the stacking direction from the tip to the electrolyte membrane than the inner convex portion over the entire extending direction.

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