JP2002246040A - Membrane-electrode joint producing method for polymer electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas diffusion electrode joint and a PEFC allowing the use of a perfluorosulfonic ionomer having high proton conductivity and superior performance in a gas diffusion electrode joint producing method for a polymer fuel cell, and the uniform formation of a thin polymer electrolytic membrane on a catalyst layer, having lower internal resistance, low-humidification or non-humidification operating adaptability and high output. SOLUTION: A coating layer is formed on the catalyst layer, a polymer electrolytic solution is applied thereon, and the coating layer is fired and removed therefrom to uniformly form the polymer electrolyte layer, without infiltrating of the polymer electrolytic solution into the catalyst layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a solid polymer electrolyte fuel cell (hereinafter referred to as "PEFC"), and more particularly to a method for producing a membrane-electrode assembly for PEFC.

[0002]

2. Description of the Related Art A membrane-electrode assembly for a PEFC comprises an assembly of a polymer electrolyte membrane 41 in the form of a film as an electrolyte and gas diffusion electrodes 46 and 47 as shown in FIG. The polymer electrolyte membrane 41 is usually supplied by a roll. FIG. 4A shows an example of a method for producing a membrane-electrode assembly, in which carbon papers 42 and 44 on which catalyst layers 43 and 45 are formed are pressed against a polymer electrolyte membrane 41 by hot pressing. is there. Alternatively, there is a method in which a catalyst layer is previously formed on a polymer electrolyte membrane by transfer, printing, or the like, and then carbon paper is pressed. In the negative electrode catalyst layer 43, a reaction represented by the following formula (1): H ₂ → 2H ⁺ + 2e ⁻ (1) occurs.
The reaction represented by the formula (2): 1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2) is occurring. When the above reaction occurs, protons generated at the negative electrode are converted into polymer electrolyte membrane 41.
Move to the positive electrode through. Such a PEFC is required to have a high output current density, but has high proton conductivity as a polymer electrolyte membrane to be used,
That is, it is required to have a low internal resistance. In order to obtain high proton conductivity, it is necessary to use a material having high proton conductivity for the polymer electrolyte membrane or to use a membrane having a thickness as small as possible.

In general, a polymer electrolyte membrane made of perfluorosulfonic acid ionomer represented by Nafion 112 manufactured by DuPont of the United States is used as a polymer electrolyte of PEFC, and the membrane has a thickness of about 30 to 50 μm. Has been put to practical use. Further, as a polymer electrolyte membrane comprising a perfluorosulfonic acid ionomer having a higher proton conductivity than Nafion, for example, Flemion SH membrane manufactured by Asahi Glass Co., Ltd. can be mentioned. There is a problem that it is easy. Therefore, a practically used membrane is about 50
It has a thickness of at least μm.

In order to make the polymer electrolyte membrane thinner,
For example, Japanese Patent Application Laid-Open No. 08-162132 discloses that a porous polytetrafluoroethylene cloth is used as a core material, and a porous polymer electrolyte resin is impregnated into the porous voids to form a polymer electrolyte membrane having strength. A method for doing so is disclosed. Specific products manufactured by this method include, for example, GOR manufactured by Japan Gore-Tex Co., Ltd.
E-SELECT film and the like. This film has been put into practical use to a thickness of about 20 to 30 μm by using a reinforcing agent.

[0005]

However, in the conventional method for manufacturing a membrane / electrode assembly used for a solid polymer electrolyte fuel cell, the polymer electrolyte membrane is supplied in a roll form. Use of a polymer electrolyte membrane thinner than 20 μm due to the difficulty of forming the polymer electrolyte into a thin film without forming defects and / or the fact that it is easily broken during the manufacturing process of the membrane / electrode assembly Was difficult. Accordingly, the present invention solves the above problem by using a perfluorosulfonic acid ionomer having high proton conductivity, comprising a thin polymer electrolyte membrane that can be formed on the catalyst layer, and having an internal resistance of An object of the present invention is to provide a low-power and high-output membrane / electrode assembly for a polymer electrolyte fuel cell. Further, the present invention prevents the raw material liquid of the polymer electrolyte membrane from infiltrating into the porous portion of the catalyst layer of the gas diffusion electrode, has a uniform thickness, does not clog the porous portion, and has excellent electrode characteristics. An object of the present invention is to provide a membrane / electrode assembly for a polymer electrolyte fuel cell.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode joined to both surfaces of a proton conductive polymer electrolyte membrane.
1) forming a coating layer on the catalyst layer;
(B1) a step of applying a polymer electrolyte solution on the coating layer, and (c1) a step of removing the coating layer to form the joined body, for a polymer electrolyte fuel cell. Provided is a method for manufacturing a membrane / electrode assembly. In this case, the coating layer has a thickness of 200
A material that sublimates below 200 ° C, a material that thermally decomposes below 200 ° C, a material that decomposes and sublimates with UV, a material that decomposes with UV and dissolves in a solvent, a water-soluble material, or a material that dissolves in an organic solvent It is valid. Further, it is effective that the coating layer is formed by screen printing, a roll coater or a spray coating method. Further, it is effective that the polymer electrolyte layer is formed by screen printing, a roll coater or a spray coating method.

Further, the present invention relates to a method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode joined to both sides of an ion-conductive polymer electrolyte membrane, wherein (a2) (B2) arranging a surface of the polymer film not having the polymer electrolyte membrane on the catalyst layer, and (c2) removing the polymer film The present invention provides a method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell, comprising: In this case, the polymer film is a material that sublimes at 200 ° C. or lower, a material that thermally decomposes at 200 ° C. or lower, a material that decomposes and sublimates with ultraviolet light, a material that decomposes with ultraviolet light and dissolves in a solvent, a water-soluble material, or an organic material. What is formed of a material soluble in a solvent is effective. Further, it is effective that the polymer electrolyte layer is formed by screen printing, a roll coater or a spray coating method.

Further, the present invention relates to a method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode joined to both sides of an ion-conductive polymer electrolyte membrane, wherein (a3) Forming a coating layer made of a polymer electrolyte, (b3) applying a polymer electrolyte solution on the coating layer, and (c3) forming the joined body. Also provided is a method for producing a membrane / electrode assembly for a molecular electrolyte fuel cell.

[0009]

DETAILED DESCRIPTION OF THE INVENTION In contrast to a conventional method for producing a membrane / electrode assembly for a fuel cell, if a polymer electrolyte membrane is formed directly on a catalyst layer, no stress is applied during the process, so that the membrane is not broken. Although a thin film should be formed, when the polymer electrolyte raw material solution is directly applied to the catalyst layer, the solution permeates the porous catalyst layer, and it has been difficult to obtain a good film. Therefore, in the present invention, in order to enable the formation of a polymer electrolyte membrane having a particularly thin film thickness, a thin polymer electrolyte membrane is first formed on a specific medium, and then the medium is removed. To obtain an interface between the polymer electrolyte membrane and the catalyst layer. Therefore, the medium referred to here must be one which has a relatively smooth surface, is not porous, and can form a thin polymer electrolyte membrane. That is,
The present invention, on both sides of the proton conductive polymer electrolyte membrane,
A method for producing a membrane-electrode assembly in which a catalyst layer and a gas diffusion electrode are joined, (1) a step of disposing a medium on the catalyst layer, and (2) a polymer electrolyte membrane on the medium. And (3) removing the medium to form the assembly. A method for producing a membrane-electrode assembly for a polymer electrolyte fuel cell, comprising:
However, any of the steps (1) and (2) at this time may be performed first. Hereinafter, a preferred embodiment of the method for producing an electrode for a fuel cell according to the present invention will be described by dividing which of the steps (1) and (2) is performed first.

Embodiment 1 A method for manufacturing a fuel cell electrode according to Embodiment 1 of the present invention is a method in which a coating layer is first formed as a medium on a catalyst layer. (B1) a step of applying a polymer electrolyte solution on the coating layer, and (c1) a step of removing the coating layer to form a joined body.
Since the coating layer needs to be finally removed, in step (a1), a material that sublimes at 200 ° C. or lower, a material that thermally decomposes at 200 ° C. or lower, a material that decomposes and sublimates with ultraviolet light, It is effective to form the coating layer with a material that dissolves in water, a water-soluble material, or a material that dissolves in an organic solvent. Where 200
The reason why the temperature was set to not more than ℃ is that the perfluorosulfonic acid ionomer which is a polymer electrolyte does not thermally decompose at a temperature of not more than 200 ° C.

Here, examples of the material that sublimates at 200 ° C. or lower include triazole, triazine, benzotriazole, nitrobenzotriazole, methylbenzotriazole, naphthol, quinoline, hydroxyquinoline, quinolidine, morpholine, cyclohexylamine, and the like. A layer can be formed by forming these into a paste with a solvent such as alcohol or ether and applying the paste. Examples of the material thermally decomposed at 200 ° C. or lower include polyoxymethylene, poly-α-methylene sulfone, polypropylene oxide, polyisoprene, polymethyl methacrylate, and polymethyl acrylate.

As a material which is decomposed and sublimated by ultraviolet rays, for example, poly (2,2,2-trifluoroethyl α-
For example, a resist agent such as chloroacrylate) and a material which is easily depolymerized by ultraviolet rays such as polyacetal can be used. As a material that is decomposed by ultraviolet rays and dissolved in a solvent, a photosensitive resin can be used, and examples thereof include poly (methyl isopropenyl ketone).

Examples of the water-soluble material include synthetic polymers such as polyvinyl alcohol, polyethylene oxide, polyacrylamide, polyacrylamine, and polyvinylpyrrolidone; natural starch such as potato starch, tapioca starch, and corn starch; Examples include pregelatinized, etherified and esterified processed starch, cellulose derivatives such as carboxymethylcellulose and methylcellulose, proteins, gelatin, glue, casein, shellac, gum arabic, dextrin and the like. Examples of the material dissolved in the organic solvent include natural rubber, asphalt, chloroprene resin, nitrile rubber resin, styrene resin, butyl rubber, polysulfide, silicone rubber, vinyl acetate, nitrocellulose, and the like.

Next, from the viewpoint that the coating layer can form a thin and uniform layer,
It is effective to form by screen printing, roll coater or spray coating method. A person skilled in the art can appropriately select a method for forming the coating layer and a drying method thereafter depending on the material of the coating layer, the forming conditions, and the like. Further, as for the material for forming the coating layer, the concentration, the temperature and the like may be selected within a range having a film forming ability.

Next, in the first embodiment, the step (b)
As 1), a polymer electrolyte membrane is formed on the coating layer formed as described above. Unlike the conventional case of using a polymer electrolyte membrane supplied by a roll,
As described above, according to this method, a polymer electrolyte membrane thinner than the conventional one can be formed. As the material for forming the polymer electrolyte membrane, the same polymer electrolyte solution as in the related art may be used, and the concentration, temperature, and the like can be appropriately selected. In addition, this polymer electrolyte layer,
Similar to the coating layer, it is effective to form the layer by screen printing, a roll coater or a spray coating method.

Finally, the coating layer is removed. This removal can be selected according to the type and characteristics of the material forming the coating layer, and a method such as heating, ultraviolet irradiation, or dissolution in water or a solvent can be used. However, the method used here needs to be performed under conditions that do not impair the performance of the obtained joined body,
Such conditions can be appropriately selected by those skilled in the art.

Second Embodiment Next, a second embodiment of the present invention relating to a case where a polymer electrolyte membrane is formed on a medium first, comprises a catalyst layer and a gas diffusion layer on both sides of an ion-conductive polymer electrolyte membrane. (A2) a step of forming a polymer electrolyte membrane on a polymer film, comprising:
2) arranging a surface of the polymer film not having the polymer electrolyte membrane on the catalyst layer; and (c2)
A step of removing the polymer film.

Here, a polymer film serving as a medium is formed in advance.
The same material as the coating layer in the first embodiment, that is, the polymer film is a material that sublimes at 200 ° C. or less, a material that thermally decomposes at 200 ° C. or less, a material that decomposes and sublimates with ultraviolet light, and a solvent that decomposes with ultraviolet light. , A water-soluble material, or a material soluble in an organic solvent. However, in order to form the polymer film separately from the gas diffusion electrode, a polymer film may be formed by, for example, dropping or coating on a glass plate, a Petri dish, or a film, and drying.

Then, a polymer electrolyte membrane is formed on the polymer film. Also in this case, it can be formed by screen printing, a roll coater or a spray coating method using the same material as in the first embodiment.
Then, a polymer film having a polymer electrolyte membrane formed on one side is disposed on the catalyst layer of the gas diffusion electrode on the side having no polymer electrolyte membrane, and finally the coating layer is formed in the first embodiment. The conjugate according to the present invention can be obtained by removing the polymer film in the same manner as when removing the polymer film. The method for arranging the polymer film on the gas diffusion electrode is not particularly limited, and may be, for example, a mechanical arrangement.

Embodiment 3 Further, the present invention relates to a method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode joined to both sides of an ion-conductive polymer electrolyte membrane, wherein (a3) Forming a coating layer made of a polymer electrolyte on the catalyst layer, (b)
3) A method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell, comprising: a step of applying a polymer electrolyte solution on the coating layer; and (c3) a step of forming the assembly. I will provide a. In this embodiment,
The coating layer is made of the same material as the polymer electrolyte membrane. As described above, a medium is required to prevent the polymer electrolyte solution from penetrating into the catalyst layer. In this embodiment, the gel layer is formed by utilizing the gelation phenomenon of the polymer electrolyte. It is used as a layer for preventing permeation into the catalyst layer. That is, first, a small amount of the polymer electrolyte membrane raw material solution is sprayed on the catalyst layer by spraying to volatilize the solvent. When a solvent such as ethyl alcohol is used, the polymer electrolyte solution gels when the concentration of the polymer electrolyte reaches 10% to 20%. A gel layer is formed. At this time, if the distance between the spray and the catalyst layer, the spray conditions, and the spray amount are appropriately selected, the solvent volatilization state of the polymer electrolyte solution when reaching the catalyst layer surface can be controlled. It is possible to limit the intrusion to only the surface. When this operation is repeated several times, a thin gelled layer made of a solution of the polymer electrolyte can be formed so as to fill the surface of the catalyst layer. Thereafter, the catalyst layer is heated at 100 ° C to 14 ° C.
Drying at 0 ° C. for a short time forms a coating layer that is no longer soluble in solvents such as ethyl alcohol.
Next, when a raw material solution for the polymer electrolyte membrane is applied thereon, the coating layer serves as a barrier layer for the raw material solution to the catalyst layer, and the polymer electrolyte membrane can be formed favorably. Since the coating layer is made of the same material as the polymer electrolyte membrane, it can exhibit proton conductivity as a part of the polymer electrolyte membrane after the formation of the polymer electrolyte membrane.

In the above method, a polymer electrolyte membrane in which a gas diffusion electrode is in contact with one side of the polymer electrolyte membrane is obtained. However, since a thin polymer electrolyte membrane is already formed, the polymer electrolyte membrane is A catalyst layer and carbon paper are joined to the other surface to obtain a fuel cell membrane / electrode assembly. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0022]

Embodiment 1 FIG. 1 schematically shows a manufacturing process of a membrane / electrode assembly for a fuel cell in this embodiment. First, in order to obtain the catalyst layer 3, 10 to 30 Wt% of the platinum catalyst is added.
The supported carbon powder is put on N-butyl acetate and the above platinum and N-
Mix so that the weight ratio of butyl acetate is 1: 120,
A dispersion of a platinum catalyst was obtained. While stirring the dispersion with a magnetic stirrer, an ethyl alcohol solution of a polymer electrolyte was added dropwise until the platinum amount and the polymer electrolyte mass became 1: 2, and then a paste was formed using an ultrasonic disperser. . As an ethyl alcohol solution of the polymer electrolyte, a Flemion FSS-1 solution manufactured by Asahi Glass Co., Ltd. was used.

This catalyst paste is obtained by previously welding 20 to 60 Wt% of a tetrafluoroethylene-hexafluoropropylene copolymer as a support 4.
It was applied on one side of a 100 mm × 200 mm carbon paper manufactured by Toray and then dried at 50 to 60 ° C. to obtain a gas diffusion electrode. The thickness of the catalyst layer 3 thus formed is 30 to 4
It was 0μ. Next, an aqueous solution having a concentration of 3% and a viscosity of 4000 CPS of hydroxypropylmethylcellulose (60SH4000 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied by a roll coater method, and then dried to form a coating layer 2.

Next, a solution of Flemion FSS-1 which is a polymer electrolyte solution whose viscosity has been adjusted is applied to the catalyst layer side of the gas diffusion electrode having the coating layer formed thereon by a roll coater method, and then ethyl alcohol as a solvent is dried. A gas diffusion electrode as shown in FIG. 1 (c) was obtained. Next, it was baked at 200 ° C. for 30 minutes using a dryer. By this baking step, the coating layer 2 formed on the catalyst layer 3 can be eliminated, and the gas diffusion electrode in which the polymer electrolyte membrane 1 is in contact with the catalyst layer 3 as shown in FIG. was gotten. At this time, the thickness of the polymer electrolyte membrane 1 was 5 to 20 μm, and a polymer electrolyte membrane layer having a uniform thickness without infiltration into the catalyst layer was obtained.

A gas diffusion electrode having a polymer electrolyte layer having a thickness of 12 μ and a gas diffusion electrode having only a catalyst layer formed as described above is sandwiched so that the catalyst layer faces the inside,
The temperature was raised to 150 ° C. while applying a pressure of 5 kgf / cm ² using a hot press machine, and then the temperature was raised to 150 ° C .;
/ Cm ² for 10 minutes. Using this assembly, a cell temperature of 75 ° C., a negative electrode bubbler temperature of 70 ° C., a positive electrode bubbler temperature of 65 ° C., a hydrogen utilization of 70%, and an air utilization of 4
When the voltage at 0.7 A / cm ² at 0% was measured, 0.70 V was obtained. That is, the output power is 0.49
W / cm ² and high output power could be obtained. In the present embodiment, an example in which carbon paper is used as the support 4 is described. However, the support 4 does not necessarily need to be carbon paper, and may be a polymer sheet such as PP or PET. When the support 4 is such a sheet, carbon paper may be bonded after peeling.

Comparative Example 1 FIG. 4 schematically shows a manufacturing process of a fuel cell membrane / electrode assembly according to this comparative example. Gas diffusion electrodes 46 and 47 were obtained in the same manner as in Example 1 until the catalyst layers 43 and 45 were formed. Next,
The gas diffusion electrodes 46 and 47 are opposed to the catalyst layers 43 and 45 inward, and a Flemion SH50 (thickness: 50 μm) 41, which is a polymer electrolyte membrane manufactured by Asahi Glass Co., Ltd., is sandwiched between the gas diffusion electrodes 46 and 47. / Cm ² while increasing the temperature to 150 ° C. while increasing the temperature to 150 ° C.
Hot pressing was performed at 0 kgf / cm ² . When a voltage at 0.7 A / cm ² at 75 ° C. was measured in the same manner as in Example 1 using this joined body, 0.55 V was obtained. That is, the output power was 0.385 W / cm ² , and the output was lower than that of Example 1. This is due to the internal resistance of the polymer electrolyte membrane, and a large film thickness causes a large voltage drop.

Comparative Example 2 In this comparative example, a polymer electrolyte solution was directly applied to the catalyst layer 3 by a roll coater method. Other conditions were the same as in Example 1 to produce a gas diffusion electrode. In the gas diffusion electrode thus manufactured, FIG.
As shown in (1), the polymer electrolyte solution penetrated into the porous portion of the catalyst layer 3 during coating. Therefore, the surface of the polymer electrolyte layer film had many small irregularities, the film thickness was not uniform, and the gas diffusion property of the catalyst layer 3 did not function, so that it could not be used as an electrode.

Embodiment 2 FIG. 2 schematically shows a manufacturing process of a membrane / electrode assembly for a fuel cell in this embodiment. First, a gas diffusion electrode with a catalyst layer 3 was obtained in the same manner as in Example 1. Next, a 1% aqueous solution of hydroxypropylmethylcellulose (60SH4000 manufactured by Shin-Etsu Chemical Co., Ltd.) was dropped on a glass plate by a casting method and developed, and then dried to obtain a film 22. The film 22
After a solution of Flemion FSS-1 as a polymer electrolyte was applied thereon by a roll coater method, an ethyl alcohol component was removed to obtain a film with a polymer electrolyte layer as shown in FIG. 2A. At this time, the thickness of the polymer electrolyte layer was 12 μm.

Next, as shown in FIG. 2 (b), the film with a polymer electrolyte layer was bonded to the gas diffusion electrode with a catalyst layer 3 prepared previously, and dried at 200 ° C. for 30 minutes using a dryer. Fired. By this baking step, the film 22 could be eliminated, and a gas diffusion electrode in which the polymer electrolyte membrane 1 was in contact with the catalyst layer 3 as shown in FIG. 2C was obtained. The gas diffusion electrode with a polymer electrolyte layer produced as described above and the gas diffusion electrode with only the catalyst layer 3 were sandwiched in such a manner that the catalyst layers face inward in the same manner as in Example 1, and 5 kgf was applied using a hot press. / Cm ² while pressurizing to 150 ° C.
It was hot pressed at gf / cm ² . When the voltage at 0.7 A / cm ² at 75 ° C. was measured using this joined body,
0.69 V was obtained. That is, the output power is 0.48 W /
cm ² , and a high output was obtained as in Example 1.

Embodiment 3 FIG. 3 schematically shows a manufacturing process of a membrane / electrode assembly for a fuel cell in this embodiment. First, a gas diffusion electrode with a catalyst layer 3 was produced in the same manner as in Example 1. Next, this gas diffusion electrode with a catalyst layer was
The solution was placed on a hot plate at 0 ° C., and an 8 wt% solution of polymer electrolyte Flemion FSS-1 in ethyl alcohol was spray-coated on the catalyst layer of the gas diffusion electrode using a spray nozzle 5. First, 5cc of Flemion FSS-
One solution was sprayed onto the catalyst layer of the gas diffusion electrode from a distance of 80 cm or more, and a gelling layer was deposited and formed on the very surface of the catalyst layer while the ethyl alcohol as the solvent was volatilized while descending. Next, 5 cc of Flemion FSS-1 solution was further sprayed on this. After this operation was repeated three times, the gas diffusion electrode was left on a hot plate at 100 ° C. for 10 minutes to cure the polymer electrolyte gel to form a polymer electrolyte thin layer 31. Thereafter, the Flemion FSS-1 solution was applied on the thin layer 31 by a roll coater. Next, the gas diffusion electrode on which the polymer electrolyte membrane was formed was dried at 150 ° C. for 60 minutes to obtain a gas diffusion electrode with a polymer electrolyte layer as shown in FIG. At this time, the thickness of the polymer electrolyte layer was 12 μm.

The gas diffusion electrode with a polymer electrolyte layer produced as described above and the gas diffusion electrode with only the catalyst layer 3 were sandwiched in the same manner as in Example 1 so that the catalyst layers face inside, and a hot press machine was used. While applying pressure to 5 kgf / cm ²
Raise the temperature to 50 ° C, raise the temperature to 150 ° C, then 50kgf / c
It was hot-pressed at m ^2. When a voltage at 0.7 A / cm ² at 75 ° C. was measured using this joined body, 0.71
V was obtained. That is, the output power was 0.50 W / cm ² , and a high output was obtained as in Example 1. In this embodiment, the roll coater method was used, but a uniform coating layer and a polymer electrolyte layer can be similarly formed by a screen printing method.

[0032]

As described above, according to the present invention, a perfluorosulfonic acid ionomer having high proton conductivity and excellent performance can be used, and a thin polymer electrolyte membrane can be formed on the catalyst layer. Therefore, a high-output gas diffusion electrode assembly and PEFC having low internal resistance and suitable for low-humidification or non-humidification operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a manufacturing process of a fuel cell membrane / electrode assembly in Example 1.

FIG. 2 is a schematic view showing a manufacturing process of a fuel cell membrane / electrode assembly in Example 2.

FIG. 3 is a schematic view showing a manufacturing process of a fuel cell membrane / electrode assembly in Example 3.

FIG. 4 is a schematic view showing a manufacturing process of a fuel cell membrane / electrode assembly in Comparative Example 1.

FIG. 5 is a schematic view showing a fuel cell membrane / electrode assembly in Comparative Example 2.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 polymer electrolyte membrane 2 coating layer 3 catalyst layer 4 support 5 spray nozzle 8 polymer electrolyte solution entry boundary 22 polymer film 31 polymer electrolyte membrane thin layer 41 polymer electrolyte membrane 42, 44 carbon paper 43, 45 catalyst Layer 46, 47 Gas diffusion electrode

Claims (3)

[Claims] 1. A method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode bonded to both surfaces of a hydrogen ion conductive polymer electrolyte membrane, wherein (a1) coating on the catalyst layer Forming a layer, (b1) applying a polymer electrolyte solution on the coating layer, and (c)
1) A method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell, comprising a step of forming the assembly by removing the coating layer. 2. A method for producing a membrane / electrode assembly comprising a catalyst layer and a gas diffusion electrode joined to both surfaces of a hydrogen ion conductive polymer electrolyte membrane, wherein (a2) a method comprising: Forming a molecular electrolyte membrane, (b2) arranging a surface of the polymer film not having the polymer electrolyte membrane on the catalyst layer, and (c2) removing the polymer film. A method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell, comprising: 3. A method for producing a membrane-electrode assembly comprising a catalyst layer and a gas diffusion electrode bonded to both surfaces of a hydrogen ion conductive polymer electrolyte membrane, wherein (a3) a method comprising: Forming a coating layer made of a molecular electrolyte, (b)
3) A method for producing a membrane-electrode assembly for a polymer electrolyte fuel cell, comprising: a step of applying a polymer electrolyte solution on the coating layer; and (c3) a step of forming the assembly. .