KR101073014B1 - A membrane electrode assembly for fuel cell and a fuel cell comprising the same - Google Patents

Abstract

The present invention relates to a fuel cell membrane / electrode assembly and a fuel cell comprising the same, wherein the membrane / electrode assembly comprises a polymer electrolyte membrane; A first catalyst layer disposed on both surfaces of the polymer electrolyte membrane in contact with the polymer electrolyte membrane; An ion conductive porous layer disposed in contact with one surface of the first catalyst layer; A second catalyst layer disposed in contact with one surface of the ion conductive porous layer; And a gas diffusion layer sequentially disposed in contact with one surface of the second catalyst layer, wherein the ion conductive porous layer comprises an electron conductive material; And an ion conductive material selected from the group consisting of ion conductive polymers, ion conductive ceramic materials, and mixtures thereof. The present invention also provides a membrane / electrode assembly; Provided is a fuel cell having a bipolar plate sandwiching the membrane / electrode assembly.

Fuel cell, ion conductive porous layer, membrane / electrode assembly, catalyst

Description

Membrane / electrode assembly for fuel cell and fuel cell comprising same {A MEMBRANE ELECTRODE ASSEMBLY FOR FUEL CELL AND A FUEL CELL COMPRISING THE SAME}

1 is a view schematically showing an operating state of a fuel cell including a polymer electrolyte membrane.

2 is a cross-sectional view of a membrane / electrode assembly according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: fuel cell 10a: anode electrode

10b: cathode electrode 20: membrane / electrode assembly

15: polymer electrolyte membrane 30: polymer membrane

32, 32 ': first catalyst layer 34, 34': ion conductive porous layer

36, 36 ': second catalyst layer 38, 38': gas diffusion layer

[Industrial use]

The present invention relates to a fuel cell membrane / electrode assembly and a fuel cell including the same, and more particularly to a fuel cell membrane / electrode capable of obtaining a high electrochemical oxidation / reduction reaction rate by increasing an effective area in which a catalyst layer exists. It relates to a conjugate and a fuel cell comprising the same.

BACKGROUND ART [0002]

A fuel cell is a power generation system that directly converts the chemical reaction energy of hydrogen and oxygen contained in hydrocarbon-based materials such as methanol, ethanol and natural gas into electrical energy.

Fuel cells are classified into phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, polymer electrolyte or alkaline fuel cells, etc., depending on the type of electrolyte used. Each of these fuel cells operates on essentially the same principle, but differs in the type of fuel used, operating temperature, catalyst, electrolyte, and the like.

Among these, the polymer electrolyte fuel cell (PEMFC), which is being developed recently, has superior output characteristics compared to other fuel cells, has a low operating temperature, fast start-up and response characteristics, and a mobile power source such as an automobile. Of course, it has a wide range of applications, such as distributed power supply for homes, public buildings and small power supply for electronic devices.

Such a PEMFC basically includes a stack, a reformer, a fuel tank, a fuel pump, and the like to constitute a system. The stack forms the body of the fuel cell, and the fuel pump supplies the fuel in the fuel tank to the reformer. The reformer reforms the fuel to generate hydrogen gas and supplies the hydrogen gas to the stack. Thus, the PEMFC feeds the fuel in the fuel tank to the reformer by operation of a fuel pump, which reforms the fuel to produce hydrogen gas, and electrochemically reacts the hydrogen gas with oxygen in the stack to produce electrical energy. Generate.

On the other hand, the fuel cell may employ a direct methanol fuel cell (DMFC) method that can supply a liquid methanol fuel directly to the stack. Such a direct methanol fuel cell fuel cell, unlike the polymer electrolyte fuel cell, the reformer is excluded.

In the fuel cell system as described above, the stack that substantially generates electricity has a structure in which several to tens of unit cells consisting of a membrane electrode assembly (MEA) and a bipolar plate are stacked. Have The membrane / electrode assembly has a structure in which an anode electrode (also called "fuel electrode" or "oxide electrode") and a cathode electrode (also called "air electrode" or "reduction electrode") are bonded to each other with a polymer electrolyte membrane interposed therebetween. Have

1 is a view schematically showing an operating state of the fuel cell 1. The membrane / electrode assembly 20 in the fuel cell includes an anode electrode 10a, a cathode electrode 10b, and a polymer electrolyte membrane 15. Referring to FIG. 1, when hydrogen gas or fuel is supplied to the anode electrode 10a, an electrochemical oxidation reaction occurs and ionizes to hydrogen ions H ⁺ and electrons e ⁻ . The ionized hydrogen ions move to the cathode electrode 10b through the polymer electrolyte membrane 15 and electrons move to the cathode electrode 10a through an external circuit. The hydrogen ions transferred to the cathode electrode 10b generate an electrochemical reduction reaction with oxygen supplied to the cathode electrode 10b to generate heat of reaction and water, and electrical energy is generated by the movement of electrons. This electrochemical reaction can be represented by the following scheme.

Scheme 1

The ^{_{anode: H 2 → 2H + + 2e}} -

_{^{Cathode: 2H + + 1/2 O 2 +}} 2e - → H 2 O

The anode electrode or cathode electrode typically comprises a platinum (Pt) catalyst. However, since platinum is an expensive precious metal, there is a problem that it cannot be used in large quantities, and in the related art, in order to reduce the amount of platinum used, platinum is mainly supported on carbon.

However, when the platinum catalyst supported on carbon is used, the thickness of the catalyst layer becomes thick, there is a limit in the storage amount of platinum, and the contact state between the catalyst layer and the electrolyte membrane is not good, thereby degrading the performance of the fuel cell.

Therefore, there is a need to develop a membrane-electrode assembly that can exhibit excellent battery performance while reducing the amount of catalyst contained in the catalyst layer of the membrane / electrode assembly.

An object of the present invention is to provide a fuel cell membrane / electrode assembly and a fuel cell including the same, which can increase the effective area of the catalyst layer to obtain a high electrochemical oxidation / reduction reaction rate.

In order to achieve the above object, the present invention is a polymer electrolyte membrane; A first catalyst layer disposed on both surfaces of the polymer electrolyte membrane in contact with the polymer electrolyte membrane; An ion conductive porous layer disposed in contact with one surface of the first catalyst layer; A second catalyst layer disposed in contact with one surface of the ion conductive porous layer; And a gas diffusion layer sequentially disposed in contact with one surface of the second catalyst layer, wherein the ion conductive porous layer comprises an electron conductive material; And an ion conductive material selected from the group consisting of ion conductive polymers, ion conductive ceramic materials, and mixtures thereof.

The present invention also provides a membrane / electrode assembly; Provided is a fuel cell having a bipolar plate sandwiching the membrane / electrode assembly.

Hereinafter, the present invention will be described in more detail.

Expensive precious metals are mostly used as metal catalysts for fuel cells, and platinum is the most widely used among them. Therefore, it is most important to maintain the performance of the fuel cell while reducing the amount of the catalyst used.

As a method of reducing the amount of the catalyst used, there is a deposition method in which a catalyst layer is formed by depositing a catalyst on a substrate. However, the surface area of the catalyst layer is determined according to the surface area of the substrate on which the catalyst is deposited, and when the surface area of the catalyst layer is low, the output characteristics of the fuel cell are lowered. Therefore, it is important to widen the surface area of the substrate on which the catalyst is deposited.

In the present invention, the catalyst layer is formed on the substrate and the catalyst layer is formed on the polymer electrolyte membrane to improve the electrochemical reaction rate by increasing the effective area in which the catalyst layer is present, and then the ion conductive porous layer is positioned between the catalyst layers.

2 is a cross-sectional view of a membrane / electrode assembly according to the present invention. As shown in FIG. 2, the membrane / electrode assembly of the present invention includes a polymer membrane 30; First catalyst layers 32 and 32 'disposed on both surfaces of the polymer membrane 30 in contact with the polymer membrane; An ion conductive porous layer (34, 34 ') disposed in contact with one surface of the first catalyst layer (32, 32'); A second catalyst layer 36, 36 ′ disposed in contact with one surface of the ion conductive porous layer 34, 34 ′; And gas diffusion layers 38 and 38 'disposed in contact with one surface of the second catalyst layers 36 and 36', wherein the ion conductive porous layers 34 and 34 'are formed of an electron conductive material and an ion conductive polymer or Ceramic material.

The polymer electrolyte membrane 30 may be any polymer as long as it has a hydrogen ion conductivity, and preferably a perfluoro polymer, a benzimidazole polymer, a polyimide polymer, a polyetherimide polymer, or a polyphenylene sulfide. Type polymer, polysulfone type polymer, polyether sulfone type polymer, polyether ketone type polymer, polyether ether ketone type polymer, polyphenylquinoxaline type polymer, etc. may be used, and specific examples thereof include poly (perfluorosulfone). Phosphonic acid), poly (perfluorocarboxylic acid), tetrafluoroethylene and fluorovinylether copolymers containing sulfonic acid groups, defluorinated sulfonated polyetherketones, aryl ketones or poly (2,2 '-( m-phenylene) -5,5'-bibenzimidazole) (poly (2,2 '-(m-phenylene) -5,5'-bibenzimidazole)), poly (2,5-benzimidazole), etc. Polybenzimidazole, etc. are available It may be, but is not limited thereto. In general, the polymer electrolyte membrane has a thickness of 10 to 200㎛.

The gas diffusion layers 38 and 38 ′ may be carbon paper or carbon cloth, and may be used by water repellent treatment with polytetrafluoroethylene (PTFE) or the like. The gas diffusion layer serves to support the polymer membrane / electrode assembly and to diffuse the reactant into the polymer membrane / electrode assembly.

The catalyst metals are deposited on both surfaces of the polymer electrolyte membrane 30 to form the first catalyst layers 32 and 32 ', and the catalyst metals are deposited on one surface of the gas diffusion layers 38 and 38' to form the second catalyst layers 36 and 36. Form '). The catalyst layer is formed by depositing a so-called metal catalyst which catalyzes the related reaction (oxidation of hydrogen and reduction of oxygen), and the metal catalyst is preferably platinum, ruthenium, osmium, platinum-transition metal alloy, or the like. Can be used. Examples of the transition metal include chromium, copper, nickel, ruthenium, osmium, and the like.

The content of the catalyst per unit area included in the first catalyst layer and the second catalyst layer is preferably 0.001 to 0.5 mg / cm ² , more preferably 0.01 to 0.05 mg / cm ² . When the content of the catalyst contained in the first catalyst layer and the second catalyst layer is less than 0.001 mg / cm ^2, the efficiency of the fuel cell is not sufficient, if the content of the catalyst exceeds 0.5 mg / cm ² may be less effective in the use of the catalyst.

In addition, the specific surface area of the catalyst included in the first catalyst layer and the second catalyst layer is preferably 10 to 1000 m ² / g. Oxidation / reaction of the fuel cell takes place on the surface of the catalyst, so the larger the specific surface area, the better the fuel cell efficiency. Therefore, when the specific surface area of the catalyst is less than 10 m ² / g, the efficiency of the fuel cell is lowered, and when it exceeds 1000 m ² / g there is a manufacturing difficulty.

Examples of the deposition method include chemical vapor deposition such as plasma chemical vapor deposition and laser chemical vapor deposition, sputtering, ion beam evaporation, vacuum thermal evaporation, laser ablation, and thermal deposition. evaporation, physical vapor deposition, etc. may be used, but is not limited thereto.

Ion conductive porous layers 34 and 34 'are disposed between the first catalyst layer and the second catalyst layer. The ion conductive porous layer may be formed in the first catalyst layer or may be formed in the second catalyst layer. The ion conductive porous layer includes an electron conductive material and an ion conductive polymer or ceramic material to facilitate the transfer of electrons and ions, and has a porous structure to facilitate the transfer of fuel gas or oxygen gas, Can improve the output.

As the electron conductive material, an electron conductive carbon or an electron conductive polymer may be used. As the electron conductive carbon, graphite, carbon black, carbon nanotube, activated carbon, or the like may be used. As the electron conductive polymer, polyaniline, polypyrrole, polythiophene, polyacene, or the like may be used. In addition, any ion-conductive polymer can be used as long as it has hydrogen ion conductivity, and tetrafluoroethylene and fluorovinyl ether including polyperfluorosulfonic acid, poly (perfluorocarboxylic acid), and sulfonic acid groups. Copolymers, defluorinated sulfide polyetherketones, aryl ketones or poly (2,2 '-(m-phenylene) -5,5'-bibenzimidazole) (poly (2,2'-(m-phenylene ), Polybenzimidazoles such as poly (2,5-benzimidazole), and the like. Ionic conductive ceramic materials include zirconium phosphate, zirconium oxide, silicating sticky acid, phosphotungstic acid and phosphomolybdic acid.

The electron conductive material and the ion conductive polymer are present in a weight ratio of 1: 5 to 50: 1, preferably in a weight ratio of 1: 3 to 2: 1. If the content of the electron conductive material is added lower than 1: 5, the network of electron transport is not formed, and if the content of electron conductive material is greater than 50: 1, the network of ion transport is not formed. When an ion conductive ceramic material is used, the electron conductive material and the ion conductive ceramic material are preferably used in a weight ratio of 1: 2 to 20: 1. If the electron conductive material is lower than 1: 2, the electron transfer network cannot be formed. If the electron conductive material is larger than 20: 1, the ion transfer network cannot be formed.

The ion conductive porous layer has a porosity of 30 to 70%. The ion conductive porous layer is an electron conductive material; Ionically conductive polymers or ceramic materials; And a composition including a solvent may be formed by wet coating a gas diffusion layer on which the second catalyst layer is formed or a polymer membrane on which the first catalyst layer is formed. As the solvent, alcohols such as ethanol, isopropyl alcohol, n-propyl alcohol, butyl alcohol, water, dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP) and the like may be preferably used.

In the case of the ion conductive polymer, since it may serve as a binder, it is not necessary to add a separate binder, but in the case of the ion conductive ceramic material, it is preferable to add the binder. The binder may be polyterafluoroethylene (PTFE), fluorinated propylene copolymer, butadiene-styrene copolymer, polyvinylidene fluoride, polyvinyl alcohol, cellulose acetate, polyvinylidene fluoride-hexafluoropropylene Copolymers (PVdF-HFP) and the like can be used. The binder is preferably used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total amount of the electron conductive material and the ion conductive ceramic material.

The coating process may be a screen printing method, a spray coating method or a coating method using a doctor blade, a gravure coating method, a dip coating method, a silk screen method, a painting method, etc., depending on the viscosity of the composition, but is not limited thereto.

The solvent may be volatilized by heating at a temperature between 20 and 180 degrees to remove the solvent after coating. In addition, a process of volatilizing the solvent under vacuum at a temperature of 20 to 180 degrees may also be added.

The ion conductive porous layer may be formed by coating a composition including an electron conductive material, an ion conductive polymer or a ceramic material, and a solvent on a release film and transferring the same to a second catalyst layer formed on a gas diffusion layer or a first catalyst layer formed on a polymer membrane. It may be.                     

The ion conductive porous layer may further include a moisture-containing hydrogel such as crosslinked polyethylene oxide, crosslinked polyvinyl alcohol, or the like, or a moisture-containing inorganic material such as silica and alumina. As such, when the moisture-containing hydrogel or the inorganic material is included, water generated from the cathode may be delivered to the catalyst layer and the polymer membrane, thereby enabling a non-humidifying operation without requiring additional humidification. The hydrogel or inorganic material is preferably present in an amount of 1 to 20% by weight.

When the ion conductive porous layers 34 and 34 'are formed in the first catalyst layers 32 and 32' formed on the polymer membrane 30, the gas diffusion layers 38 and 38 'on which the second catalyst layers 36 and 36' are formed. And the polymer membrane 30 are laminated so that the ion conductive porous layers 34 and 34 'are positioned between the first catalyst layers 32 and 32' and the second catalyst layers 36 and 36 'and are bonded by applying heat or pressure. Can be. In addition, when the ion conductive porous layers 34 and 34 'are formed in the second catalyst layers 36 and 36' formed in the gas diffusion layers 38 and 38 ', the polymer membrane 30 having the first catalyst layers 32 and 32' is formed. ) And the gas diffusion layers 38 and 38 ′ may be laminated such that an ion conductive porous layer is positioned between the first catalyst layer and the second catalyst layer and applied by heat or pressure.

Before forming the second catalyst layers 36 and 36 ′ in the gas diffusion layers 38 and 38 ′, the conductive powder may be coated to form a microporous layer. The microporous layer may include a conductive powder having a small particle diameter, for example, carbon powder, carbon black, acetylene black, activated carbon, carbon fiber, fullerene or carbon nanotubes.

As the binder resin, polytetrafluoroethylene (PTFE), polyvinylidene fluoride, polyvinyl alcohol, cellulose acetate, and the like may be preferably used, and as the solvent, ethanol, isopropyl alcohol, n-propyl alcohol, butyl Alcohols such as alcohol, water, dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), and the like may be preferably used. The coating process may be screen printing, spray coating, or a coating method using a doctor blade according to the viscosity of the composition, but is not limited thereto.

The prepared membrane / electrode assembly may be inserted between a gas flow channel and a bipolar plate on which a cooling channel is formed to manufacture a unit cell, and stacked to manufacture a stack, and then inserted between the two end plates to manufacture a fuel cell. Can be. Fuel cells can all be manufactured by conventional techniques in the art.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only one preferred embodiment of the present invention and the present invention is not limited to the following examples.

(Example 1: Preparation of membrane / electrode assembly and unit cell)

Vulcan XC 6 parts by weight of electron conductive carbon, 14 parts by weight of poly (perfluorosulfonic acid) polymer (Nafion 112) by ion conductive polymer and 80 parts by weight of water / isopropyl alcohol = 4/1 (volume ratio) by solvent Mixing produced a coating composition. Platinum was sputtered on both sides of the poly (perfluorosulfonic acid) polymer membrane (Nafion 112, DuPont) to form a first catalyst layer, and the first catalyst layer was coated with the composition, followed by drying to form an ion conductive porous layer. Platinum was sputtered on carbon paper to form a second catalyst layer to prepare an anode electrode and a cathode electrode. The content of the catalyst in the first catalyst layer was 0.02 mg / cm ² and the content of the catalyst in the second catalyst layer was 0.05 mg / cm ² . A membrane / electrode assembly was prepared by inserting and pressing the polymer membrane having the ion conductive porous layer and the first catalyst layer sequentially formed on both surfaces between the anode electrode and the cathode electrode.

The prepared membrane / electrode assembly is inserted between two gaskets, and then inserted into two bipolar plates in which a gas channel channel and a cooling channel of a predetermined shape are formed, and then compressed into a copper end plate. The battery was prepared.

(Example 2)

10 parts by weight of carbon nanotubes of 30 microns in diameter and 1000 microns in length of electron conductive carbon, 10 parts by weight of ZrP in ionic conductive ceramics, and 5 parts of poly (perfluorosulfonic acid) polymer as a binder (Dupont Nafion 112) A coating composition was prepared by mixing 75 parts by weight of water / isopropyl alcohol = 4/1 (volume ratio) with parts and a solvent. A unit cell was prepared in the same manner as in the above example except that the composition was coated on a first catalyst layer formed by depositing platinum on both surfaces of a poly (perfluorosulfonic acid) polymer membrane (Nafion 112, DuPont). The content of the catalyst in the first catalyst layer was 0.02 mg / cm ² and the content of the catalyst in the second catalyst layer was 0.05 mg / cm ² .

(Example 3)

Coating carbon black with carbon powder on carbon paper to form a microporous layer, and then sputtering platinum to form a second catalyst layer using an electrode prepared as a cathode and an anode electrode, and Example 1 between the cathode and the anode electrode. In the same manner as in Example 1, except that a membrane / electrode assembly was prepared by inserting and pressing a poly (perfluorosulfonic acid) polymer membrane sequentially formed on both surfaces of the ion conductive porous layer and the first catalyst layer prepared in The battery was prepared. The content of the catalyst in the first catalyst layer was 0.02 mg / cm ² and the content of the catalyst in the second catalyst layer was 0.05 mg / cm ² .

(Compare battery performance)

 In order to compare the performance of the membrane-electrode assembly prepared in the above embodiment, each membrane-electrode assembly was sandwiched on a bipolar plate to prepare a unit battery cell. Table 1 shows the results of measuring the current voltage by introducing hydrogen air in a humidified state at a temperature of 60 ° C. and atmospheric pressure into a unit battery cell.

TABLE 1

Example 1 Example 2 Example 3 0.6 V 600 mA / cm ² 800 mA / cm ² 1.2 A / cm ² 0.4 V 1.25 A / cm ² 1.8 A / cm ² 2.5 A / cm ²

As shown in Table 1, it can be seen that the current density of Examples 1 to 3 is excellent. This is thought to be because the effective area of the catalyst layer is increased and the electrochemical reaction rate is increased.

In the present invention, the first catalyst layer and the second catalyst layer is present between the polymer electrolyte membrane and the gas diffusion layer and the hydrogen ion conductive porous layer is present between the first catalyst layer and the second catalyst layer to increase the effective area of the catalyst layer, Electrochemical oxidation / reduction reaction rate can be improved.

Claims (17)

Polymer electrolyte membranes; Mainly on the polymer electrolyte membrane A first catalyst layer disposed on both sides in contact with the polymer electrolyte membrane; An ion conductive porous layer disposed in contact with one surface of the first catalyst layer; A second catalyst layer disposed in contact with one surface of the ion conductive porous layer; And Gas diffusion layers disposed in contact with one surface of the second catalyst layer are sequentially located, The ion conductive porous layer is an electron conductive material; And an ion conductive material selected from the group consisting of ion conductive polymers, ion conductive ceramic materials, and mixtures thereof. The polymer electrolyte membrane of claim 1, wherein the polymer electrolyte membrane is made of a polymer selected from the group consisting of a fluorine-based polymer having hydrogen ion conductivity, a benzimidazole-based polymer, a ketone-based polymer, an ester-based polymer, an amide-based polymer, and an imide-based polymer. Membrane / electrode assembly for phosphorus fuel cell. 3. The polymer electrolyte membrane according to claim 2, wherein the polymer electrolyte membrane is tetrafluoroethylene and fluorovinyl ether copolymer containing poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), sulfonic acid groups, defluorinated sulfide Polyetherketone, aryl ketone or poly (2,2 '-(m-phenylene) -5,5'-bibenzimidazole) (poly (2,2'-(m-phenylene) -5,5'- bibenzimidazole)), poly (2,5-benzimidazole) is a fuel cell membrane electrode assembly comprising a polymer selected from the group consisting of. The fuel cell membrane of claim 1, wherein the electron conductive material is at least one selected from the group consisting of graphite, carbon black, carbon nanotubes, activated carbon, polyaniline, polypyrrole, polythiophene, and polyacene. Electrode assembly. The method of claim 1, wherein the ion conductive polymer is a poly (perfluorosulfonic acid), poly (perfluorocarboxylic acid), tetrafluoroethylene containing a sulfonic acid group, fluorovinyl ether copolymer, defluorinated Sulfided polyetherketones, aryl ketones or poly (2,2 '-(m-phenylene) -5,5'-bibenzimidazole) (poly (2,2'-(m-phenylene) -5,5 ' -bibenzimidazole)), poly (2,5-benzimidazole) is at least one selected from the group consisting of fuel cell membrane electrode assembly. The fuel cell membrane / electrode assembly of claim 1, wherein the ion conductive ceramic material is at least one selected from the group consisting of zirconium phosphate, zirconium oxide, silico tungstic acid, phosphotungstic acid, and phosphomolybric acid. The membrane / electrode assembly of claim 1, wherein the electron conductive material and the ion conductive polymer are present in a weight ratio of 1: 5 to 50: 1. The membrane / electrode assembly of claim 1, wherein the electron conductive material and the ion conductive ceramic material are present in a weight ratio of 1: 2 to 20: 1. The fuel cell membrane electrode assembly of claim 1, wherein the first catalyst layer and the second catalyst layer are formed by depositing a metal catalyst. 10. The membrane / electrode assembly of claim 9, wherein the metal catalyst is at least one selected from the group consisting of platinum, ruthenium, osmium, and a platinum-transition metal alloy. The fuel cell membrane / electrode assembly according to claim 1, wherein the content of the catalyst contained in the first catalyst layer and the second catalyst layer is 0.001 to 0.5 mg / cm ² per unit area. The fuel cell membrane / electrode assembly according to claim 1, wherein the specific surface area of the catalyst of the catalyst contained in the first catalyst layer and the second catalyst layer is 10 to 1000 m ² / g. The membrane / electrode assembly of claim 1, wherein the ion conductive porous layer further comprises a moisture-containing hydrogel or a moisture-insoluble inorganic material. The fuel cell membrane electrode assembly of claim 13, wherein the hydrogel is crosslinked polyethylene oxide, crosslinked polyvinyl alcohol, or a mixture thereof. The fuel cell membrane electrode assembly of claim 1, further comprising a fine pore layer between the second catalyst layer and the gas diffusion layer. The fuel cell membrane / electrode assembly according to claim 1, wherein adhesion of the polymer electrolyte membrane, the first catalyst layer, the ion conductive porous layer, the second catalyst layer, and the gas diffusion layer is performed by heat or pressure. A membrane / electrode assembly according to any one of claims 1 to 16; And a bipolar plate sandwiching the membrane / electrode assembly.

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