Membrane-electrode assembly for water electrolysis cell, manufacturing method therefor, and water electrolysis cell comprising membrane-electrode assembly

Abstract

The present disclosure relates to a membrane-electrode assembly for a water electrolysis cell, a manufacturing method therefor, and a water electrolysis cell comprising the membrane-electrode assembly for the water electrolysis cell. The membrane-electrode assembly for the water electrolysis cell comprises: a first ion conductor for forming a coating layer coated on the surface of a oxygen evolution reaction catalyst; and a second ion conductor, which is not coated on the surface of the oxygen evolution reaction catalyst, and thus the interfacial binding strength between a polymer electrolyte membrane or a porous diffusion layer (PTL) and the oxygen evolution reaction catalyst can be increased to improve mass transfer, performance and durability.

Description

Membrane-electrode assembly for electrolysis cell, method for manufacturing same, and electrolysis cell including said membrane-electrode assembly

[0001] The present disclosure relates to a membrane-electrode assembly for a water electrolysis cell, a method for manufacturing the same, and an electrolysis cell including the membrane-electrode assembly for the water electrolysis cell, and more particularly, to a membrane-electrode assembly for a water electrolysis cell that improves mass transfer, performance, and durability by increasing interfacial binding strength between a polymer electrolyte membrane or a porous diffusion layer (PTL) and an oxygen evolution reaction catalyst layer while using a CCM (Catalyst Coated Membrane) method, a method for manufacturing the same, and an electrolysis cell including the membrane-electrode assembly for the water electrolysis cell.

[0002] This disclosure relates to the results of a project (Project ID: 20022451) carried out with the support of the Materials and Components Technology Development Project of the Ministry of Trade, Industry and Energy and the Korea Institute for Advancement of Technology (KEIT).

[0003] Recent energy demands and environmental concerns demand sustainable supply, environmental friendliness, and high efficiency, and among these, hydrogen is attracting attention as a raw material for renewable energy.

[0004] Hydrogen energy is classified into gray, blue, and green hydrogen depending on the production method. Gray and blue hydrogen have the problem that carbon dioxide is generated during the production process or cannot be completely removed because they use fossil fuels.

[0005] Green hydrogen refers to hydrogen produced through the electrolysis of infinite water. Because the hydrogen production process produces no carbon dioxide, it is attracting attention as the ultimate eco-friendly energy source. Water electrolysis technology is necessary to produce green hydrogen.

[0006] Electrolysis is an electrochemical process that generates hydrogen and oxygen by electrolyzing water and transporting ions across a membrane. Electrolysis can be divided into two half-cell reactions: the hydrogen evolution reaction (HER), which occurs at the reduction electrode, and the oxygen evolution reaction (OER), which occurs at the oxidation electrode.

[0007] The types of electrolysis mentioned above are, depending on the electrolyte membrane, representative ones such as polymer electrolyte membrane electrolysis (PEM), alkaline electrolysis (AEC), anion exchange membrane electrolysis (AEM), and solid oxide electrolysis (SOECs).

[0008] Among them, in the system of a polymer electrolyte membrane water electrolysis cell (PEMWE), the membrane electrode assembly (MEA) that actually generates hydrogen has a structure in which an oxygen generation electrode, which is an electrode where an oxygen generation reaction occurs, and a hydrogen generation electrode, where a hydrogen generation reaction occurs, are positioned with a polymer electrolyte membrane containing a hydrogen ion conductive polymer interposed therebetween.

[0009] In addition, a gas diffusion layer (GDL) or a porous diffusion layer (PTL) and a gasket are sequentially laminated on the outer part of the electrode, that is, the outer part where the oxygen generation electrode and the hydrogen generation electrode are located, and a separator having a flow field formed therein to supply water and discharge hydrogen generated by the reaction is located on the outer side of the gas diffusion layer or the porous diffusion layer, and an end plate is coupled to the outermost part to support or fix each of the above components.

[0010] Manufacturing these membrane-electrode assemblies requires technology for positioning oxygen-evolution electrodes and hydrogen-evolution electrodes on both sides of a polymer electrolyte membrane. These technologies are broadly divided into the Catalyst Coated Substrate (CCS) method and the Catalyst Coated Membrane (CCM) method. The CCS method involves forming a catalyst layer on a gas diffusion layer (GDL) or porous diffusion layer (PTL) and then hot-pressing it to bond it to a polymer electrolyte membrane. The CCM method primarily involves directly bonding the catalyst layer to a polymer electrolyte membrane.

[0011] The CCM method is divided into the direct coating method and the decal lamination method. The direct coating method is a method of forming an electrode by directly coating an electrode slurry on a polymer electrolyte membrane, and the decal lamination method is a method of coating an electrode slurry mixed with a catalyst, an ion conductor, and a solvent on a support such as a release film such as Teflon or an imide film, drying it to create a catalyst layer, and then aligning the catalyst layer on at least one side of the polymer electrolyte membrane and applying heat and pressure to transfer it. The decal lamination method generally transfers the electrode to the polymer electrolyte membrane using a flat-panel hot press or roll press.

[0012] The direct coating method has the problem of making it difficult to secure a process for mass production due to the characteristic that the polymer electrolyte membrane easily changes when it comes into contact with the electrode slurry or is exposed to moisture.

[0013] The decal lamination method generally has the problem that when heat transfer is performed using a flat press or roll press, it is difficult to apply even pressure to the entire area of ​​the electrode, and thus it is difficult to ensure uniformity of the product, which lowers the quality and reduces the performance of the fuel cell.

[0014] According to one embodiment, a membrane-electrode assembly for a water electrolysis cell is provided, which includes a first ion conductor forming a coating layer coated on the surface of an oxygen evolution reaction catalyst and a second ion conductor not coated on the surface of the oxygen evolution reaction catalyst, thereby increasing interfacial binding strength between a polymer electrolyte membrane or a porous diffusion layer (PTL) and an oxygen evolution reaction catalyst layer, thereby improving mass transfer, performance, and durability.

[0015] According to another embodiment, a method for manufacturing a membrane-electrode assembly for the above-described hydrolysis cell is provided.

[0016] According to another embodiment, a water electrolysis cell comprising the membrane-electrode assembly is provided.

[0017] According to one embodiment, a membrane-electrode assembly for a water electrolysis cell comprises: a polymer electrolyte membrane; and an oxygen generation electrode positioned on one side of the polymer electrolyte membrane and including a catalyst layer for oxygen evolution reaction; and a hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane; wherein the catalyst layer for oxygen evolution reaction comprises: a catalyst for oxygen evolution reaction including active particles including a first noble metal oxide; a coating layer coating a surface of the catalyst for oxygen evolution reaction and including a first ion conductor; and a second ion conductor not coated on the surface of the catalyst for oxygen evolution reaction.

[0018] The above first noble metal oxide is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x (wherein M includes Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and x is an integer from 1 to 3), or a combination thereof.

[0019] The above oxygen generation reaction catalyst further includes a carrier that supports the active particles, and the carrier may include a second noble metal oxide different from the first noble metal oxide.

[0020] The area of ​​the above coating layer may be 30% or more of the entire surface of the oxygen generation reaction catalyst.

[0021] The thickness of the above coating layer may be in the range of 1 nm to 15 nm.

[0022] The above first ion conductor may be included in an amount of 3 to 50 parts by weight relative to 100 parts by weight of the oxygen generation reaction catalyst.

[0023] The first ion conductor and the second ion conductor each independently include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a combination thereof, and the first ion conductor and the second ion conductor may be the same or different.

[0024] The equivalent weight (EW) of the first ion conductor and the second ion conductor are each independently within a range of 600 g / eq to 1100 g / eq, and the equivalent weight of the first ion conductor and the equivalent weight of the second ion conductor may be different from each other.

[0025] One of the first ion conductor and the second ion conductor may be a fluorine-based ion conductor and the other may be a hydrocarbon-based ion conductor; the first ion conductor may be a first hydrocarbon-based ion conductor and the second ion conductor may be a second hydrocarbon-based ion conductor different from the first hydrocarbon-based ion conductor; or the first ion conductor may be a first fluorine-based ion conductor and the second ion conductor may be a second fluorine-based ion conductor different from the first fluorine-based ion conductor.

[0026] The content of the second ion conductor may be included within a range of 20 parts by weight to 80 parts by weight based on 100 parts by weight of the total content of the first ion conductor and the second ion conductor included in the oxygen generation reaction catalyst layer.

[0027] The above-mentioned catalyst layer for oxygen generation reaction may further include a functional additive including a radical scavenger, a gas barrier particle, a hydrophilic inorganic additive, a heat dissipating material, or a combination thereof.

[0028] The above functional additive may be included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the second ion conductor.

[0029] The membrane-electrode assembly for the above-mentioned electrolysis cell may further include an ionomer-rich layer positioned between the oxygen generation reaction catalyst layer and the polymer electrolyte membrane, and including the second ion conductor.

[0030] The above hydrogen generation electrode may include a carbon-based carrier and a hydrogen generation catalyst including active particles containing a precious metal and supported on the carbon-based carrier.

[0031] The polymer electrolyte membrane may include a porous support including a plurality of pores, and an ion conductor filling the pores of the porous support.

[0032] According to another embodiment, a method for manufacturing a membrane-electrode assembly for a water electrolysis cell comprises the steps of: (S1) mixing an oxygen evolution reaction catalyst and a first ion conductor and then heat-treating the mixture to prepare an oxygen evolution reaction catalyst coated with the first ion conductor; (S2) adding the oxygen evolution reaction catalyst coated with the first ion conductor and a second ion conductor to a solvent to prepare a catalyst layer-forming composition; and (S3) forming an oxygen evolution reaction catalyst layer on at least one side of a polymer electrolyte membrane using the catalyst layer-forming composition, wherein the oxygen evolution reaction catalyst includes active particles including a first noble metal oxide, and the oxygen evolution reaction catalyst coated with the first ion conductor includes a coating layer that coats the surfaces of the oxygen evolution reaction catalyst and the oxygen evolution reaction catalyst and includes the first ion conductor.

[0033] In the above step S1, the heat treatment can be performed at a temperature in the range of 110°C to 220°C for 1 to 4 hours.

[0034] In the above step S3, forming the catalyst layer for the oxygen generation reaction may be done by directly coating the catalyst layer forming composition on the polymer electrolyte membrane, or by coating the catalyst layer forming composition on a substrate to form the catalyst layer for the oxygen generation reaction and then transferring the oxygen generation reaction catalyst layer to the polymer electrolyte membrane.

[0035] After the above step S3, a drying step is further included, and the drying step is performed at a temperature in the range of 60°C to 110°C for 3 to 50 minutes, and in the drying step, the second ion conductor that is not coated on the surface of the oxygen generation reaction catalyst can precipitate toward the polymer electrolyte membrane to form an ion conductor rich layer.

[0036] According to another embodiment, a water electrolysis cell comprises a membrane-electrode assembly for the water electrolysis cell.

[0037] According to one embodiment, a membrane-electrode assembly for a water electrolysis cell includes a first ion conductor forming a coating layer coated on the surface of an oxygen evolution reaction catalyst and a second ion conductor not coated on the surface of the oxygen evolution reaction catalyst, thereby increasing interfacial binding strength between a polymer electrolyte membrane or a porous diffusion layer (PTL) and an oxygen evolution reaction catalyst layer, thereby improving material transfer, performance, and durability.

[0038] Figure 1 is a schematic diagram showing a process for forming a catalyst for oxygen generation reaction coated with a first ion conductor according to one embodiment.

[0039] Figures 2 and 3 are schematic diagrams showing that, in a method for manufacturing a membrane-electrode assembly according to one embodiment, a composition for forming a catalyst layer is coated on one side of a polymer electrolyte membrane or substrate and then dried, thereby causing a second ion conductor to precipitate to the interface between the polymer electrolyte membrane or substrate and the catalyst layer for oxygen generation reaction.

[0040] Figure 4 is a transmission electron microscope (TEM) photograph of a catalyst for oxygen generation reaction coated with a first ion conductor according to Manufacturing Example 1.

[0041] Figures 5 and 6 are scanning electron microscope (SEM) photographs showing cross-sections of the catalyst layer of the membrane-electrode assembly manufactured in Examples 1-1 and 1-2.

[0042] Figures 7 to 10 are scanning electron microscope (SEM) photographs showing the surface of the catalyst layer of the membrane-electrode assembly manufactured in Examples 2-1 to 3 and Comparative Example 1.

[0043] Figure 11 is a graph showing the results of evaluating the IV characteristics of the membrane-electrode assemblies manufactured in Examples 1-1 to 3 and Comparative Example 1.

[0044] Hereinafter, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0045] As used herein, “combination thereof” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0046] It should be understood that the terms “include,” “comprising,” or “having” used in this specification are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0047] In this specification, terms are used solely to distinguish one component from another. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0048] Unless otherwise defined herein, "substitution" means that a hydrogen atom in a compound is replaced by a halogen atom (F, Cl, Br or I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C4 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, It means substituted with a substituent including a C2 to C20 heterocycloalkyl group or a combination thereof.

[0049] Unless otherwise defined herein, “alkyl group” means a straight or branched chain, saturated, monovalent hydrocarbon group (e.g., methyl group, ethyl group, propyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, iso-amyl group, hexyl group, etc.).

[0050] Unless otherwise defined herein, “alkenyl group” means a straight or branched chain, saturated, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., an ethenyl group).

[0051] Unless otherwise defined herein, “alkoxy group” means an alkyl group linked through oxygen, for example, methoxy, ethoxy, and sec-butyloxy groups.

[0052] In this specification, the indications S1, S2, S3,…, Sn, etc. are for convenience only to refer to each step, and do not mean that each step proceeds in a chronological order or that no other additional steps are included between each step.

[0053]

[0054] 1. Membrane-electrode assembly for electrolysis cell

[0055] A membrane-electrode assembly for a water electrolysis cell according to one embodiment comprises: a polymer electrolyte membrane; an oxygen evolution electrode positioned on one side of the polymer electrolyte membrane and including a catalyst layer for oxygen evolution reaction; and a hydrogen evolution electrode positioned on the other side of the polymer electrolyte membrane.

[0056] Hereinafter, the oxygen generation electrode, the hydrogen generation electrode, and the polymer electrolyte membrane will be described.

[0057] The above oxygen evolution electrode refers to an electrode where an oxygen evolution reaction (OER) occurs.

[0058] The oxygen generation reaction catalyst layer included in the oxygen generation electrode according to one embodiment includes an oxygen generation reaction catalyst including active particles including a first noble metal oxide, a coating layer that coats the surface of the oxygen generation reaction catalyst and includes a first ion conductor, and a second ion conductor that is not coated on the surface of the oxygen generation reaction catalyst.

[0059] In order to distinguish between the noble metal oxide contained in the active particles and the noble metal oxide contained in the carrier described below, the noble metal oxide contained in the active particles is denoted as "first", and the noble metal oxide contained in the carrier is denoted as "second." This notation is merely to help clearly identify the noble metal oxide contained in the active particles and the carrier, and this order does not indicate a specific priority with respect to their properties.

[0060] The above first noble metal oxide is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x(wherein M includes Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and x is an integer from 1 to 3), or a combination thereof.

[0061] The above-mentioned oxygen generation reaction catalyst may contain only active particles comprising the first noble metal oxide or may further contain a carrier supporting the active particles.

[0062] The carrier may include a second noble metal oxide different from the first noble metal oxide.

[0063] The type of the above second noble metal oxide is not limited as long as it can be used as a carrier for supporting a catalyst for a typical oxygen generation reaction.

[0064] For example, the second precious metal oxide may include tungsten oxide, titanium oxide, nickel oxide, ruthenium oxide, tantalum oxide, tin oxide, cobalt oxide, or a combination thereof.

[0065] The above coating layer includes a first ion conductor.

[0066] The first ion conductor may include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a mixture thereof. In order to distinguish between the ion conductor coated on the surface of the oxygen evolution reaction catalyst and the ion conductor not coated on the surface of the oxygen evolution reaction catalyst, which will be described later, the ion conductor coated on the surface of the oxygen evolution reaction catalyst is referred to as “first”, and the ion conductor not coated on the surface of the oxygen evolution reaction catalyst is referred to as “second”. This notation is only helpful in clearly distinguishing the ion conductor coated on the surface of the oxygen evolution reaction catalyst and the ion conductor not coated on the surface of the oxygen evolution reaction catalyst, and this order does not indicate a specific priority with respect to their characteristics.

[0067] The above fluorine-based ion conductor is (i) a fluorine-based polymer containing fluorine in the main chain, having a cation exchange group or an anion exchange group, or (ii) a partially fluorinated polymer such as a polystyrene-graft-ethylenetetrafluoroethylene copolymer, a polystyrene-graft-polytetrafluoroethylene copolymer, etc.

[0068] The above cation exchange group is a functional group capable of transferring a cation such as a proton, and may be, for example, an acidic group such as a sulfonic acid group, a carboxyl group, a boronic acid group, a phosphoric acid group, an imide group, a sulfonimide group, or a sulfonamide group.

[0069] The above anion exchange group is a functional group capable of transferring anions such as hydroxyl ions, carbonate ions, or bicarbonate ions.

[0070] Examples of the above fluorinated ion conductors include, but are not limited to, (i) poly(perfluorosulfonic acid), (ii) poly(perfluorocarboxylic acid), (iii) copolymers of tetrafluoroethylene and fluorovinyl ether containing sulfonic acid groups, and (iv) defluorinated sulfurized polyether ketones.

[0071] The above hydrocarbon-based ion conductor is a hydrocarbon-based polymer having a cation exchange group or an anion exchange group (for example, a hydrocarbon-based polymer including in the main chain imidazole, benzimidazole, polyamide, polyamideimide, polyimide, polyacetal, polyethylene, polypropylene, acrylic resin, polyester, polysulfone, polyether, polyetherimide, polyester, polyethersulfone, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyetheretherketone, polyetherketone, polyarylethersulfone, polyphosphazene, polyphenylquinoxaline, or a combination thereof).

[0072] The above hydrocarbon ion conductors are sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (SPEEK), sulfonated polybenzimidazole (SPBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S-PS), sulfonated polyphosphazene, sulfonated polyquinoxaline, sulfonated polyketone, sulfonated polyphenylene oxide, sulfonated polyether sulfone, sulfonated polyether ketone, sulfonated Sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene sulfide sulfone, sulfonated polyphenylene sulfide sulfone nitrile, sulfonated polyarylene ether, sulfonated polyarylene ethernitrile, sulfonated polyarylene ether ether nitrile,and polyarylene ether sulfone ketones, but are not limited to these.

[0073] The method for forming a coating layer on the surface of the above oxygen generation reaction catalyst can be formed according to a known method, and can be formed according to the method described below.

[0074] The area of ​​the coating layer may be within a predetermined range relative to the entire surface of the oxygen evolution reaction catalyst. By adjusting the area of ​​the coating layer relative to the entire surface of the oxygen evolution reaction catalyst to be within a predetermined range, it is possible to contribute to the formation of an organic structure of the oxygen evolution reaction catalyst layer, thereby facilitating the configuration of ion and electron transfer paths, thereby improving performance, and to provide a membrane-electrode assembly with improved durability by increasing the bonding between oxygen evolution reaction catalysts and between oxygen evolution reaction catalysts and a second ion conductor.

[0075] For example, the lower limit of the area of ​​the coating layer relative to the entire surface of the oxygen generation reaction catalyst may be about 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100%, and the upper limit is not limited, but may be about 100%, 99%, 98%, 97%, 96%, 95%, 90% or 85%.

[0076] The area of ​​the coating layer may be equal to or greater than any one of the lower limits described above, relative to the entire surface of the oxygen evolution reaction catalyst; or may be equal to or greater than any one of the lower limits described above, but less than or equal to any one of the upper limits described above. The area of ​​the coating layer may be adjusted according to the weight of the first ion conductor relative to 100 parts by weight of the oxygen evolution reaction catalyst.

[0077] The above coating layer coating the surface of the oxygen generation reaction catalyst means that, when the oxygen generation reaction catalyst includes only active particles, the coating layer is present on the surface of the active particles, and when the oxygen generation reaction catalyst further includes active particles and a carrier that supports the active particles, the coating layer is present on the surface of the active particles or / and the surface of the carrier.

[0078] The coating layer may have a thickness within a predetermined range. For example, the lower limit of the thickness of the coating layer may be about 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm, and the upper limit may be about 15 nm, 14 nm, 13 nm, 12 nm, 11 nm, or 10 nm.

[0079] The thickness of the coating layer may be in a range of greater than or equal to any one of the lower limits described above; less than or equal to any one of the upper limits described above; or greater than or equal to any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0080] The above first ion conductor may be included within a predetermined range relative to 100 parts by weight of the oxygen generation reaction catalyst. As described above, the area of ​​the coating layer may be adjusted depending on the content of the first ion conductor relative to 100 parts by weight of the oxygen generation reaction catalyst, and therefore, the content of the first ion conductor may be appropriately adjusted to secure an area of ​​the coating layer within the above-described range.

[0081] For example, with respect to 100 parts by weight of the oxygen generation reaction catalyst, the lower limit of the content of the first ion conductor may be about 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight, and the upper limit may be about 50 parts by weight, 48 parts by weight, 46 parts by weight, 44 parts by weight, 42 parts by weight, 40 parts by weight, 38 parts by weight, 36 parts by weight, 34 parts by weight, 32 parts by weight, 30 parts by weight, 28 parts by weight, 26 parts by weight, 24 parts by weight, 22 parts by weight, or 20 parts by weight.

[0082] The content of the first ion conductor may be included within a range that is equal to or greater than any one of the lower limits described above, relative to 100 parts by weight of the oxygen evolution reaction catalyst; equal to or less than any one of the upper limits described above; or equal to or greater than any one of the lower limits described above and equal to or less than any one of the upper limits described above. By including the first ion conductor within a predetermined range relative to 100 parts by weight of the oxygen evolution reaction catalyst, it contributes to the formation of an organic structure of the oxygen evolution reaction catalyst layer, thereby facilitating the configuration of ion and electron transfer paths, thereby improving performance, and by increasing the bonding between the oxygen evolution reaction catalysts and between the oxygen evolution reaction catalyst and the second ion conductor, it is possible to provide a membrane-electrode assembly with improved durability.

[0083] The above second ion conductor is not coated on the surface of the oxygen generation reaction catalyst.

[0084] The second ion conductor may be the same as or different from the first ion conductor. That is, the first ion conductor and the second ion conductor may each independently include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a combination thereof. The meaning of the above “each independently” means that the types of the first ion conductor and the second ion conductor may each include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a combination thereof, and that the first ion conductor and the second ion conductor may be the same as or different from each other.

[0085] For example, the second ion conductor and the first ion conductor may be the same. In this case, examples of the second ion conductor are as described for the first ion conductor.

[0086] As another example, the second ion conductor and the first ion conductor may be different.

[0087] In one embodiment, the first ion conductor and the second ion conductor may have different equivalent weights (EW). For example, the equivalent weights (EW) of the first ion conductor and the second ion conductor are each independently within a range of 600 g / eq to 1100 g / eq, and the equivalent weights of the first ion conductor and the second ion conductor may be different from each other.

[0088] According to another embodiment, one of the first ion conductor and the second ion conductor may be a fluorine-based ion conductor, and the other may be a hydrocarbon-based ion conductor.

[0089] In another embodiment, the first ion conductor may be a first hydrocarbon-based ion conductor, and the second ion conductor may be a second hydrocarbon-based ion conductor different from the first hydrocarbon-based ion conductor. The terms “first” and “second” in the first hydrocarbon-based ion conductor and the second hydrocarbon-based ion conductor are used to distinguish between different hydrocarbon-based ion conductors. This notation is only helpful in clearly identifying that the first hydrocarbon-based ion conductor and the second hydrocarbon-based ion conductor are different from each other, and this order does not indicate a particular priority with respect to their characteristics.

[0090] Examples of the first hydrocarbon-based ion conductor and the second hydrocarbon-based ion conductor are as described in the first ion conductor.

[0091] According to another embodiment, the first ion conductor may be a first fluorine-based ion conductor, and the second ion conductor may be a second fluorine-based ion conductor different from the first fluorine-based ion conductor. In the first fluorine-based ion conductor and the second fluorine-based ion conductor, “first” and “second” are the same as those described for the first hydrocarbon-based ion conductor and the second hydrocarbon-based ion conductor.

[0092] Examples of the first fluorine-based ion conductor and the second fluorine-based ion conductor are as described in the first ion conductor.

[0093] The second ion conductor may be included within a predetermined range relative to 100 parts by weight of the total content of the first ion conductor and the second ion conductor included in the oxygen generation reaction catalyst layer.

[0094] For example, with respect to the total content of the first ion conductor and the second ion conductor included in the oxygen generation reaction catalyst layer of 100 parts by weight, the lower limit of the content of the second ion conductor may be about 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, or 60 parts by weight, and the upper limit may be about 80 parts by weight, 78 parts by weight, 76 parts by weight, 74 parts by weight, 72 parts by weight, 70 parts by weight, 68 parts by weight, 66 parts by weight, 64 parts by weight, 62 parts by weight, or 60 parts by weight.

[0095] The second ion conductor may be included within a range of at least or exceeding any one of the lower limits described above, or less than or equal to any one of the upper limits described above, or more than or exceeding any one of the lower limits described above and less than or equal to any one of the upper limits described above, relative to 100 parts by weight of the total content of the first ion conductor and the second ion conductor included in the oxygen generation reaction catalyst layer.

[0096] By including a second ion conductor within the above range in the oxygen generation reaction catalyst layer, the second ion conductor forms an ion conductor layer or a functional ion conductor layer between the polymer electrolyte membrane and the oxygen generation reaction catalyst layer, thereby increasing interfacial binding strength, thereby improving material transfer, performance, and durability.

[0097] The size of the second ion conductor may be within a predetermined range.

[0098] For example, the lower limit of the size of the second ion conductor may be about 30 nm or 35 nm, and the upper limit may be about 400 nm or 380 nm.

[0099] The size of the second ion conductor may be greater than or equal to any one of the lower limits described above; less than or equal to any one of the upper limits described above; or within a range greater than or equal to any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0100] When the second ion conductor has a size within the above range, the material can be smoothly transferred, and the location of the ion conductor rich layer can be appropriately controlled.

[0101] The above second ion conductor may have a spherical, ellipsoidal, rod-shaped or coil-shaped shape.

[0102] In addition, the catalyst layer for the oxygen generation reaction may further include a functional additive. By including the functional additive, the hydrogen permeation resistance or oxygen permeability of the membrane-electrode assembly can be increased.

[0103] The functional additive may include a radical scavenger, a gas barrier particle, a hydrophilic inorganic additive, a heat dissipating material, or a combination thereof.

[0104] The radical scavenger is an ion of a transition metal capable of decomposing hydrogen peroxide into water and oxygen and suppressing the generation of hydroxyl radicals, and examples thereof include cerium, tungsten, ruthenium, palladium, silver, rhodium, cerium, zirconium, yttrium, manganese, molybdenum, lead, vanadium, titanium, etc., and may be the metal itself, its ion form, its oxide form, its salt form, or other forms.

[0105] The radical scavenger may be CeO2, MnO2, CsO2, ZrO2, Ru, Ag, RuO2, WO3, Fe3O4, CePO4, CrPO4, AlPO4, FePO4, CeF3, FeF3, Ce2(CO3)3·8H2O, Ce(CHCOO)3·H2O, CeCl3·6 H2O, Ce(NO3)6·6H2O, Ce(NH4)2(NO3)6, Ce(NH4)4(SO4)4·4H2O, Ce(CH3COCHCOCH3)3·3H2O, Fe-porphyrin, Co-porphyrin or a mixture thereof.

[0106] The gas barrier particles may be clay, montmorillonite, saponite, laponite, mica, fluorohetorite, kaolinite, vermiculite, or mixtures thereof.

[0107] The hydrophilic inorganic additive may be SnO2, silica, alumina, zirconia, mica, zeolite, phosphotungstic acid, silicon tungstic acid, zirconium hydrogen phosphate, or a combination thereof. The hydrophilic inorganic additive can prevent a decrease in hydrogen ion conductivity under high temperature and low humidity conditions.

[0108] The heat dissipating material may be metal nanoparticles, ceramic nanoparticles, ultra-high molecular weight polyethylene, polyacetylene, polyimide, carbon nanoparticles, or a combination thereof.

[0109] For example, the heat dissipating material may be ceramic nanoparticles.

[0110] The above ceramic nanoparticles may be boron nitride, aluminum nitride, aluminum oxide, silicon carbide, beryllium oxide, or a combination thereof. Such ceramic nanoparticles have excellent thermal conductivity, so they can easily transfer heat to the outside of the oxygen evolution reaction catalyst layer described later, and can prevent moisture within the oxygen evolution reaction catalyst layer from evaporating.

[0111] In particular, among the above boron nitrides, hexagonal boron nitride (h-BN) has properties and a plate-like structure similar to graphite, compared to general boron nitride, and thus has excellent thermal conductivity, insulation, and chemical stability at high temperatures.

[0112] The average diameter of the above ceramic nanoparticles is not limited, but may be, for example, in the range of 10 nm to 500 nm or 30 nm to 300 nm.

[0113] The above functional additive may be included within a predetermined range relative to 100 parts by weight of the second ion conductor.

[0114] The lower limit of the content of the functional additive relative to 100 parts by weight of the second ion conductor may be about 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, or 5 parts by weight, and the upper limit may be about 20 parts by weight, 18 parts by weight, 16 parts by weight, 14 parts by weight, 12 parts by weight, 10 parts by weight, 9 parts by weight, 8 parts by weight, 7 parts by weight, 6 parts by weight, or 5 parts by weight.

[0115] The functional additive may be included within a range of at least or exceeding any one of the lower limits described above, or less than or equal to any one of the upper limits described above, or more than or exceeding any one of the lower limits described above and less than or equal to any one of the upper limits described above, relative to 100 parts by weight of the second ion conductor.

[0116] The membrane-electrode assembly for the above-mentioned electrolysis cell may further include an ion conductor-rich layer positioned between the oxygen evolution reaction catalyst layer and the polymer electrolyte membrane, the ion conductor-rich layer including the second ion conductor. The ion conductor-rich layer may be formed by the second ion conductor that is not coated on the surface of the oxygen evolution reaction catalyst layer, and may improve interfacial adhesion between the polymer electrolyte membrane and the oxygen evolution reaction catalyst layer, and may improve material transfer, performance, and durability.

[0117] That is, the ion conductor rich layer can be formed through a drying process according to a method for manufacturing a membrane-electrode assembly according to one embodiment. The oxygen generation reaction catalyst layer includes the ion conductor rich layer and a layer that is not the ion conductor rich layer, and the layer that is not the ion conductor rich layer is conveniently referred to as layer A.

[0118] The above layer A may not contain the second ion conductor at all, or may contain a smaller amount of the second ion conductor per unit volume than the ion conductor-rich layer, as illustrated in FIG. 2.

[0119] The above ion conductor-rich layer may further include a first ion conductor that remains uncoated on the surface of the oxygen generation reaction catalyst. This first ion conductor may be present when the uncoated first ion conductor is mixed with the second ion conductor without being removed.

[0120] That is, due to this ion conductor-rich layer, the interfacial adhesion between the polymer electrolyte membrane and the oxygen evolution reaction catalyst layer is increased, and mass transfer, mass transfer, performance, and durability can be improved.

[0121] The above hydrogen generation electrode refers to an electrode where a hydrogen evolution reaction (Hydrogen Evolution Reaction (HER)) occurs.

[0122] The above hydrogen generation electrode may include a catalyst for hydrogen generation reaction. The catalyst for hydrogen generation reaction may include active particles and a carrier.

[0123] The above active particles may include a precious metal.

[0124] For example, the precious metal may be a platinum-based precious metal.

[0125] The platinum-based precious metal may be platinum (Pt) and / or a Pt-M alloy. The M may be palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), gallium (Ga), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), zinc (Zn), tin (Sn), molybdenum (Mo), tungsten (W), lanthanum (La), or rhodium (Rh).

[0126] Specifically, the Pt-M alloy includes Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ni, Pt-Co, Pt-Y, Pt-Ru-W, Pt-Ru-Ni, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Ru-Ir-Ni, Pt-Co-Mn, Pt-Co-Ni, Pt-Co-Fe, Pt-Co-Ir, Pt-Co-S, Pt-Co-P, Pt-Fe, Pt-Fe-Ir, Pt-Fe-S, Pt-Fe-P, Pt-Au-Co, Pt-Au-Fe, Pt-Au-Ni, Pt-Ni, Pt-Ni-Ir, Pt-Cr, Pt-Cr-Ir, or a mixture thereof. Can be used.

[0127] The above carrier may be a carbon-based carrier.

[0128] The carbon-based carrier may be graphite, super P, carbon fiber, carbon sheet, carbon black, Ketjen Black, Denka black, acetylene black, carbon nanotube (CNT), carbon sphere, carbon ribbon, fullerene, activated carbon, carbon nanofiber, carbon nanowire, carbon nanoball, carbon nanohorn, carbon nanocage, carbon nanoring, ordered nano- / meso-porous carbon, carbon aerogel, mesoporous carbon, graphene, stabilized carbon, activated carbon, or a combination thereof.

[0129] The above oxygen generation electrode and the above hydrogen generation electrode may each include only a catalyst layer including an oxygen generation reaction catalyst and a hydrogen generation reaction catalyst, but may include an electrode substrate together with the catalyst layer.

[0130] At this time, the electrode substrate can play a role in supporting the electrode and diffusing the fuel and oxidant to the catalyst layer.

[0131] The electrode substrate may include a microporous layer, a porous diffusion layer, or a combination thereof.

[0132] The above microporous layer serves to enhance the diffusion effect of the reactant, and may generally include a conductive powder having a small particle size, for example, carbon powder, carbon black, acetylene black, activated carbon, metal oxide nanowire, carbon fiber, fullerene, carbon nanotube, carbon nanowire, carbon nano-horn, or carbon nano ring.

[0133] The above porous diffusion layer is made of porous titanium, carbon paper, carbon cloth, carbon felt or metal cloth (a porous film made of metal cloth in a fibrous state or a metal film formed on the surface of a cloth formed of polymer fibers).

[0134] The above microporous layer and the above porous diffusion layer may include known materials in addition to those exemplified above.

[0135] The above electrode substrate can be treated with a water-repellent fluorine resin, in which case the diffusion efficiency of reactants can be prevented from being reduced due to water generated during operation of the electrolysis cell.

[0136] As the above fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polyperfluoroalkyl vinyl ether, polyperfluorosulfonyl fluoride, alkoxy vinyl ether, fluorinated ethylene propylene, polychlorotrifluoroethylene or a copolymer thereof can be used.

[0137] The above electrode substrate can improve conductivity by using platinum or the like and prevent corrosion of the porous diffusion layer by an ion conductor, thereby preventing deterioration of electrolysis performance.

[0138] The above polymer electrolyte membrane has an ion exchange function that moves hydrogen ions generated at an oxygen generation electrode to a catalyst for hydrogen generation reaction.

[0139] A polymer electrolyte membrane according to one embodiment may include a porous support including a plurality of pores, and an ion conductor filling the pores of the porous support.

[0140] The above porous support may be a fluorine-based support or a nano web support.

[0141] The fluorine-based support may correspond to, for example, expanded polytetrafluoroethylene (e-PTFE) having a microstructure of polymer fibrils or a microstructure in which nodes are interconnected by fibrils. In addition, a film having a microstructure of polymer fibrils without nodes may also be used as the porous support.

[0142] The above nano web support may be a support in which nano fibers are integrated in the form of a non-woven fabric containing a large number of pores.

[0143] The above ion conductor may include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a combination thereof. The types of the fluorine-based ion conductor and the hydrocarbon-based ion conductor are as described above.

[0144] The ion conductor included in the polymer electrolyte membrane may be the same as or different from the first ion conductor and / or the second ion conductor included in the oxygen generation electrode. For example, the ion conductor included in the polymer electrolyte membrane may be the same as the first ion conductor and / or the second ion conductor included in the oxygen generation electrode.

[0145]

[0146] 2. Manufacturing method of membrane-electrode assembly for water electrolysis cell

[0147] A method for manufacturing a membrane-electrode assembly for a water electrolysis cell according to one embodiment includes a step (S1) of mixing an oxygen evolution reaction catalyst and a first ion conductor and then heat-treating the mixture to manufacture an oxygen evolution reaction catalyst coated with the first ion conductor; a step (S2) of adding the oxygen evolution reaction catalyst coated with the first ion conductor and a second ion conductor to a solvent to manufacture a composition for forming a catalyst layer; and a step (S3) of forming an oxygen evolution reaction catalyst layer on at least one side of a polymer electrolyte membrane using the composition for forming a catalyst layer.

[0148] First, a catalyst for oxygen generation reaction and a first ion conductor are mixed and then heat-treated to manufacture a catalyst for oxygen generation reaction coated with the first ion conductor (hereinafter, “Step S1”).

[0149] The above oxygen generation reaction catalyst refers to a catalyst before being coated with the first ion conductor, and the oxygen generation reaction catalyst coated with the first ion conductor refers to a catalyst coated with the first ion conductor.

[0150] Hereinafter, the oxygen generation reaction catalyst and the oxygen generation reaction catalyst coated with the first ion conductor will be described in more detail with reference to the drawings.

[0151] Figure 1 is a schematic diagram illustrating a process for forming an oxygen evolution reaction catalyst coated with a first ion conductor according to one embodiment. The left side of Figure 1 illustrates the oxygen evolution reaction catalyst before the first ion conductor is coated, and the right side of Figure 1 illustrates the oxygen evolution reaction catalyst after the first ion conductor is coated.

[0152] Referring to the right side of Fig. 1, the oxygen generation reaction catalyst coated with the first ion conductor includes an oxygen generation reaction catalyst and a coating layer that coats the surface of the oxygen generation reaction catalyst. The coating layer includes a first ion conductor.

[0153] The above oxygen generation reaction catalyst may contain active particles alone or may further contain a carrier that supports the active particles.

[0154] The above active particles may include a first precious metal oxide.

[0155] The carrier may include a second noble metal oxide different from the first noble metal oxide.

[0156] The types of the first noble metal oxide and the second noble metal oxide are as described in the “1. Membrane-electrode assembly of the electrolysis cell” section.

[0157] The type of the above first ion conductor is as described in the “1. Membrane-electrode assembly of the electrolysis cell” section.

[0158] The above first ion conductor may be used together with a binder, such as a non-conductive compound, to further enhance adhesion to the polymer electrolyte membrane. The amount of the binder used may be adjusted to suit the intended use.

[0159] The non-conductive compound may be polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene (ETFE), ethylene chlorotrifluoro-ethylene copolymer (ECTFE), polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), dodecylbenzenesulfonic acid, sorbitol, or a mixture thereof.

[0160] When mixing the above oxygen generation reaction catalyst and the first ion conductor, the content can be appropriately controlled.

[0161] For example, the first ion conductor can be mixed in an amount within a predetermined range with respect to 100 parts by weight of the oxygen generation reaction catalyst.

[0162] The lower limit, upper limit and range of the content of the first ion conductor relative to 100 parts by weight of the above oxygen generation reaction catalyst are as described in the “1. Membrane-electrode assembly for water electrolysis cell” section.

[0163] The above mixing can be carried out by introducing the oxygen generation reaction catalyst and the first ion conductor into a solvent. At this time, the solvent can be water, a hydrophilic solvent, an organic solvent, or a mixture thereof.

[0164] The hydrophilic solvent may have a functional group of alcohol, ketone, aldehyde, carbonate, carboxylate, carboxylic acid, ether, amide or a combination thereof, which contains a straight-chain or branched saturated or unsaturated hydrocarbon having 1 to 12 carbon atoms as a main chain, and may contain an aliphatic or aromatic cyclic compound as at least a part of the main chain. For example, the alcohol can be methanol, ethanol, isopropyl alcohol, ethoxyethanol, n-propyl alcohol, butyl alcohol, 1,2-propanediol, 1-pentanol, 1,5-pentanediol, or 1,9-nonanediol, the ketone can be heptanone or octanone, the aldehyde can be benzaldehyde or tolualdehyde, the ester can be methylpentanoate or ethyl-2-hydroxypropanoate, the carboxylic acid can be pentanoic acid or heptanoic acid, the ether can be methoxybenzene or dimethoxypropane, and the amide can be propanamide, butylamide, or dimethylacetamide.

[0165] The organic solvent may be N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, or a mixture thereof.

[0166] By mixing the oxygen generation reaction catalyst and the first ion conductor in the solvent and then heat-treating, at least a portion of the first ion conductor can be coated on the surface of the oxygen generation reaction catalyst.

[0167] The above mixing method is not limited as long as it can uniformly disperse the oxygen generation reaction catalyst and the first ion conductor within the solvent. For example, a homogeneous mixer, a high-pressure disperser, a ball mill, a powder mixer, or a resonant acoustic mixer can be used.

[0168] In the above step S1, heat treatment can be performed for a predetermined time at a temperature within a predetermined range.

[0169] For example, the lower limit of the heat treatment temperature may be about 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, 132°C, 134°C, 136°C, 138°C or 140°C, and the upper limit may be about 220°C, 215°C, 210°C, 205°C, 200°C, 195°C, 190°C, 185°C, 180°C, 175°C, 170°C, 165°C, 160°C, 155°C, 150°C, 145°C or 140°C.

[0170] The lower limit of the heat treatment time may be about 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours or 2 hours, and the upper limit may be about 4 hours, 3.8 hours, 3.6 hours, 3.4 hours, 3.2 hours, 3 hours, 2.8 hours, 2.6 hours, 2.4 hours, 2.2 hours or 2 hours.

[0171] The temperature and time of the heat treatment may be in a range of at least or exceeding any one of the lower limits described above; at most or less than any one of the upper limits described above; or at most or exceeding any one of the lower limits described above and at most or less than any one of the upper limits described above.

[0172] In the above step S1, drying may be further included after mixing and before heat treatment.

[0173] The above drying can be applied using various drying methods such as hot air drying, vacuum drying, and infrared (IR) drying. The temperature and time of the above drying can be appropriately adjusted depending on the boiling point (BP) of the solvent used.

[0174] The above drying can be performed for a predetermined time at a temperature within a predetermined range.

[0175] For example, the lower limit of the drying temperature may be about 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C or 90°C, and the upper limit may be about 100°C, 99°C, 98°C, 97°C, 96°C, 95°C, 94°C, 93°C, 92°C, 91°C or 90°C.

[0176] Additionally, the lower limit of the drying time may be about 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours, and the upper limit may be about 8 hours, 7.5 hours, 7 hours, 6.5 hours, 6 hours, 5.5 hours or 5 hours.

[0177] The temperature and time of the drying may be in a range of greater than or equal to any one of the lower limits described above; less than or equal to any one of the upper limits described above; or greater than or equal to any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0178] Next, a catalyst for oxygen generation reaction coated with the first ion conductor manufactured in step S1 and a second ion conductor are added to the solvent to manufacture a composition for forming a catalyst layer (hereinafter, “step S2”).

[0179] By first preparing the oxygen generation reaction catalyst coated with the first ion conductor and then adding the second ion conductor to the oxygen generation reaction catalyst coated with the first ion conductor, the sedimentation of the second ion conductor can be better achieved in the drying process described below, and thus an ion conductor rich layer can be formed on the polymer electrolyte membrane side.

[0180] In the above step S2, the solvent is as described in the above step S1.

[0181] The meaning and type of the above second ion conductor are as described in the “1. Membrane-electrode assembly for water electrolysis cell” section.

[0182] The second ion conductor may be added within a predetermined range relative to 100 parts by weight of the oxygen generation reaction catalyst coated with the first ion conductor.

[0183] The lower limit of the content of the second ion conductor may be about 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 12.5 parts by weight, 15 parts by weight, 17.5 parts by weight, 20 parts by weight, 22.5 parts by weight, 25 parts by weight, 27.5 parts by weight, 30 parts by weight, 32.5 parts by weight, 35 parts by weight, 37.5 parts by weight, 40 parts by weight, 40.5 parts by weight, 41 parts by weight or 41.5 parts by weight, and the upper limit may be about 70 parts by weight, 68 parts by weight, 66 parts by weight, 64 parts by weight, 62 parts by weight, 60 parts by weight, 58 parts by weight, 56 parts by weight, 54 parts by weight, 52 parts by weight, 50 parts by weight, 48 parts by weight, 46 parts by weight. It could be around 44 parts by weight or 42 parts by weight.

[0184] The second ion conductor may be added in a range of more than or exceeding any one of the lower limits described above; less than or equal to any one of the upper limits described above; or more than or exceeding any one of the lower limits described above and less than or equal to any one of the upper limits described above, relative to 100 parts by weight of the oxygen generation reaction catalyst coated with the first ion conductor.

[0185] In the above step S2, a composition for forming a catalyst layer can be manufactured by further adding a functional additive together with the second ion conductor.

[0186] The types and additive contents of the above functional additives are as described in the “1. Membrane-electrode assembly for electrolysis cell” section.

[0187] In the above step S2, the oxygen generation reaction catalyst coated with the first ion conductor and the second ion conductor may be added to the solvent and then mixed. When the functional additive is further added, the oxygen generation reaction catalyst coated with the first ion conductor, the second ion conductor, and the functional additive may be mixed.

[0188] The above mixing method is as described in step S1 above.

[0189] Next, a catalyst layer for oxygen generation reaction is formed on at least one side of the polymer electrolyte membrane using the catalyst layer forming composition manufactured according to the above step S2 (hereinafter, “step S3”).

[0190] In the above step S3, forming the catalyst layer for the oxygen generation reaction may be done by directly coating the catalyst layer forming composition on the polymer electrolyte membrane, or by coating the catalyst layer forming composition on a substrate to form the catalyst layer for the oxygen generation reaction and then transferring the oxygen generation reaction catalyst layer to the polymer electrolyte membrane.

[0191] According to one embodiment, the catalyst layer for the oxygen generation reaction can be formed by directly coating the composition for forming the catalyst layer on the polymer electrolyte membrane.

[0192] When the catalyst layer for oxygen generation reaction is formed by directly coating the composition for forming the catalyst layer on only one side of the polymer electrolyte membrane, a hydrogen generation electrode can be formed on the other side by using the CCS (Catalyst Coated Substrate) method or a CCM (Catalyst Coated Membrane) method other than direct coating.

[0193] When directly coating the composition for forming the catalyst layer on the polymer electrolyte membrane, the composition for forming the catalyst layer, in which the oxygen generation reaction catalyst coated with the first ion conductor is dispersed, can be continuously or intermittently transferred to a coater and then uniformly applied to the polymer electrolyte membrane at a constant thickness.

[0194] For example, the composition for forming the catalyst layer may be continuously transferred to a coater such as a die, gravure, bar, or comma coater, and then applied using a method such as slot die coating, bar coating, comma coating, screen printing, spray coating, doctor blade coating, or brush coating.

[0195] According to another embodiment, the catalyst layer for oxygen generation reaction may be formed by coating the composition for forming the catalyst layer on a substrate, and then transferring the catalyst layer for oxygen generation reaction to the polymer electrolyte membrane to form the catalyst layer for oxygen generation reaction.

[0196] When a catalyst layer for oxygen generation reaction is formed on only one side of the polymer electrolyte membrane according to the above transfer process, a hydrogen generation electrode can be formed on the other side using a CCS (Catalyst Coated Substrate) method or a CCM (Catalyst Coated Membrane) method other than direct coating.

[0197] The above description is not limited in type as long as it has heterogeneity. For example, the above-mentioned substrate may be selected from the group consisting of polyethylene glycol (PEG), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyolefin (PO), polyvinyl alcohol (PVA), polyurethane (PU), nylon, polycarbonate (PC), polyester, polyacrylonitrile (PAN), polyacetal (POM), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), cyclic polyolefin (COP), modified polyolefin (MPPO), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyether sulfone (PET), and the like. It may include a cyclic olefin copolymer (COC), triacetylcellulose (TAC) film, polyvinyl alcohol (PVA) film, polyimide (PI) film, polystyrene (PS), or a mixture thereof.

[0198] The above transcription process can utilize a known method.

[0199] According to the manufacturing method of the above membrane-electrode assembly, the interfacial adhesion between the polymer electrolyte membrane or porous diffusion layer (PTL) and the oxygen evolution reaction catalyst layer can be improved by using a second ion conductor that is not coated on the surface of the oxygen evolution reaction catalyst, and material transfer, performance and durability can be improved, and hydrogen permeation resistance or oxygen permeability can be increased.

[0200] The method for manufacturing the membrane-electrode assembly may further include a drying step after step S3. In the drying step, the second ion conductor, which is not coated on the surface of the oxygen generation reaction catalyst, may precipitate toward the polymer electrolyte membrane or porous diffusion layer (PTL) to form an ion conductor-rich layer.

[0201] The type of drying method performed in the above drying step is as described in the drying of the above S1 step.

[0202] For example, the lower limit of the temperature of the drying step may be about 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, and the upper limit may be about 110°C, 108°C, 106°C, 104°C, 102°C, 100°C, 98°C, 96°C, 94°C, 92°C or 90°C.

[0203] Additionally, the lower limit of the time of the drying step may be about 3 minutes, 5 minutes, 7 minutes, 9 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, and the upper limit may be about 50 minutes, 45 minutes, 40 minutes, 35 minutes, 30 minutes or 20 minutes.

[0204] The time and temperature of the drying step may each have a range of greater than or equal to any one of the lower limits described above; less than or equal to any one of the upper limits described above; or greater than or equal to any one of the lower limits described above and less than or equal to any one of the upper limits described above.

[0205] FIG. 2 is a schematic diagram showing a method for manufacturing a membrane-electrode assembly according to one embodiment, in which a composition for forming a catalyst layer is directly coated on one side of a polymer electrolyte membrane and then dried, thereby causing a second ion conductor to precipitate to the interface between the polymer electrolyte membrane and the catalyst layer for oxygen generation reaction.

[0206] Referring to the left side of Fig. 2, it can be confirmed that the composition (4) for forming a catalyst layer coated on the polymer electrolyte membrane (1) has a catalyst (2) for oxygen generation reaction coated with a first ion conductor and a second ion conductor (3) uniformly distributed.

[0207] Referring to the right side of Fig. 2, during the drying process, the second ion conductor is precipitated toward the polymer electrolyte membrane (1) to form an ion conductor-rich layer (5). In Fig. 2, the second ion conductor is illustrated as having completely precipitated and existing only in the ion conductor-rich layer (5), but is not limited thereto. For example, the second ion conductor may not only be located in the ion conductor-rich layer, but may also be located between the oxygen evolution reaction catalysts coated with the first ion conductor on the ion conductor-rich layer.

[0208] In the above step S3, when a catalyst layer for oxygen generation reaction is formed by coating a composition for forming a catalyst layer on a substrate and then transferring the catalyst layer for oxygen generation reaction to the polymer electrolyte membrane to form the catalyst layer for oxygen generation reaction, a drying step can be performed after coating on the substrate.

[0209] FIG. 3 is a schematic diagram showing that, in a method for manufacturing a membrane-electrode assembly according to one embodiment, a composition for forming a catalyst layer is coated on a substrate and then dried, thereby causing a second ion conductor to precipitate to the interface between the substrate and the catalyst layer for oxygen generation reaction.

[0210] The left side of Fig. 3 shows a state in which a composition (4) for forming a catalyst layer is coated on a substrate (6).

[0211] The right side of Fig. 3 shows that as the drying step is performed while the composition for forming a catalyst layer is coated on the substrate, the second ion conductor is deposited toward the substrate (6) at the interface between the substrate and the catalyst layer for oxygen generation reaction, thereby forming an ion conductor rich layer (5).

[0212] The second ion conductor may be deposited toward the substrate (6) to form an ion conductor rich layer (5), and the second ion conductor may be located not only in the ion conductor rich layer, but also between the oxygen generation reaction catalysts coated with the first ion conductor on the ion conductor rich layer.

[0213] When the oxygen evolution reaction catalyst layer having the ion conductor rich layer formed thereon is transferred to the polymer electrolyte membrane, and the oxygen evolution reaction catalyst layer is formed on the polymer electrolyte membrane according to the transfer process, an ion conductor rich layer can be formed on the opposite surface of the interface between the polymer electrolyte membrane and the oxygen evolution reaction catalyst layer.

[0214] A porous diffusion layer (PTL) can be positioned later on the interface where the above ion conductor rich layer is formed, and accordingly, the bonding between the porous diffusion layer and the oxygen generation reaction catalyst layer can be strengthened.

[0215]

[0216] 3. Susan Hae-cell

[0217] A hydrolysis cell according to one embodiment may include the membrane-electrode assembly.

[0218] The above electrolytic cell is the same as the known one except that it includes a membrane-electrode assembly according to the present application, and therefore a detailed description thereof is omitted.

[0219] Hereinafter, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0220]

[0221] Manufacturing Example 1. Catalyst for oxygen generation reaction (A) coated with first ion conductor

[0222] A solvent containing water and ethanol mixed in a weight ratio of 9:1 (=water:ethanol) is added to the reaction vessel, and IrO from commercial Heraeus is added as a catalyst for oxygen generation reaction to the solvent. x / TiO2 and an amorphous first ion conductor (EW=1000 g / eq) were added and dispersed using a homogeneous mixer to prepare a dispersion mixture.

[0223] At this time, IrO from commercial Heraeus was used so that the solid content was 3%. x / TiO2 was added in an amount of about 10 g, and the first ion conductor was the commercial IrO x / 20 parts by weight was added per 100 parts by weight of TiO2.

[0224] After drying the above dispersion compound at 90°C for 5 hours, the dried dispersion mixture was heat-treated at 140°C for 2 hours.

[0225] As a result, a catalyst (A) for oxygen generation reaction coated with the first ion conductor, in which a coating layer including the first ion conductor is formed on the surface of the catalyst for oxygen generation reaction, was formed.

[0226] The thickness of the above coating layer was approximately 3 nm, and the area of ​​the coating layer was approximately 85% on average compared to the entire surface of the oxygen generation reaction catalyst according to Evaluation Example 1.

[0227] A transmission electron microscope (TEM) image of the oxygen evolution reaction catalyst (A) coated with the above first ion conductor is shown in Fig. 4.

[0228]

[0229] Manufacturing Example 2. Catalyst for oxygen generation reaction coated with first ion conductor (B)

[0230] In the above manufacturing example 1, the first ion conductor is the commercial IrO x / An oxygen generation reaction catalyst (B) coated with a first ion conductor was manufactured in the same manner as in Manufacturing Example 1, except that 3.5 parts by weight was added instead of 20 parts by weight per 100 parts by weight of TiO2.

[0231] At this time, the thickness of the coating layer was about 1 nm, and the area of ​​the coating layer was about 50% on average compared to the entire surface of the oxygen generation reaction catalyst according to Evaluation Example 1.

[0232]

[0233] Example 1-1.

[0234] A solvent containing water and n-propanol in a weight ratio of 4:6 (=water:n-propanol) was introduced into a reaction vessel, and the oxygen generation reaction catalyst (A) coated with the first ion conductor according to Manufacturing Example 1 was dispersed in the solvent using a homogeneous mixer. A second ion conductor (EW=720 g / eq) was added so as to be 1.5 times the amount of the first ion conductor added, and dispersed using a homogeneous mixer to prepare a composition for forming a catalyst layer.

[0235] The second ion conductor was added in an amount of about 41.6 parts by weight per 100 parts by weight of the oxygen generation reaction catalyst coated with the first ion conductor.

[0236] The catalyst layer-forming composition was directly applied to one side of the polymer electrolyte membrane having a thickness of 100 μm using a slot die to a coating thickness of 150 μm, and dried with hot air at a temperature of 90°C for 20 minutes to form a catalyst layer for oxygen evolution reaction on one side of the membrane-electrode assembly. A hydrogen evolution electrode (Tanaka, TEC10E50E) was formed on the other side on which the catalyst layer for oxygen evolution reaction was not formed, thereby manufacturing a membrane-electrode assembly.

[0237] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Example 1-1 are shown in Fig. 5.

[0238] As can be seen in Fig. 5, an oxygen generation electrode having an ion conductor rich layer with an average thickness of 3 μm was formed toward the polymer electrolyte membrane.

[0239]

[0240] Example 1-2.

[0241] In the above Example 1-1, a membrane-electrode assembly was manufactured in the same manner as in Example 1-1, except that CeO2 from Sigma-Aldrich was added as a functional additive together with the second ion conductor.

[0242] At this time, the functional additive was added in an amount of about 5 parts by weight per 100 parts by weight of the second ion conductor.

[0243] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Example 1-2 are shown in Fig. 6.

[0244] As can be seen in Fig. 6, an oxygen generation electrode with an average thickness of 3 μm containing CeO2 particles was formed in the ion conductor rich layer toward the polymer electrolyte membrane.

[0245]

[0246] Example 2-1.

[0247] A solvent containing water and n-propanol in a weight ratio of 4:6 (=water:n-propanol) was introduced into a reaction vessel, and the oxygen generation reaction catalyst (A) coated with the first ion conductor according to Manufacturing Example 1 was dispersed in the solvent using a homogeneous mixer. A second ion conductor (EW=720 g / eq) was added so as to be 1.5 times the amount of the first ion conductor added, and dispersed using a homogeneous mixer to prepare a composition for forming a catalyst layer.

[0248] The second ion conductor was added in an amount of about 41.6 parts by weight per 100 parts by weight of the oxygen generation reaction catalyst coated with the first ion conductor.

[0249] The composition for forming the catalyst layer was directly applied to one side of a polyimide film of PI Advanced Materials Co., Ltd. with a thickness of 150 μm using a slot die to form a catalyst layer for oxygen generation reaction with a coating thickness of 150 μm.

[0250] A membrane-electrode assembly was manufactured in the same manner as in Example 1-1, except that the catalyst layer for the oxygen generation reaction was transferred to one side of the polymer electrolyte membrane having a thickness of 100 μm at a temperature of 160°C and a pressure of 2 MPa for 3 minutes, and a hydrogen generation electrode was formed on the other side of the polymer electrolyte membrane to manufacture a membrane-electrode assembly.

[0251] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Example 2-1 are shown in Fig. 7.

[0252]

[0253] Example 2-2.

[0254] In the above Example 2-1, a membrane-electrode assembly was manufactured in the same manner as in Example 2-1, except that h-BN (hexagonal boron nitride) from Sigma-Aldrich was added as a functional additive together with the second ion conductor.

[0255] At this time, the functional additive was added in an amount of about 5 parts by weight per 100 parts by weight of the second ion conductor.

[0256] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Example 2-2 are shown in Fig. 8.

[0257]

[0258] Example 3.

[0259] A membrane-electrode assembly was manufactured in the same manner as in Example 1-1, except that the oxygen evolution reaction catalyst (B) coated with the first ion conductor according to Manufacturing Example 2 was used instead of the oxygen evolution reaction catalyst (A) coated with the first ion conductor according to Manufacturing Example 1 in Example 1-1.

[0260] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Example 3 are shown in Fig. 9.

[0261]

[0262] Comparative Example 1.

[0263] In Example 1-1, the first ion conductor is a commercial IrO that is not coated. x A membrane-electrode assembly was manufactured in the same manner as in Example 1-1 except that / TiO2 (Alfa Aesar, 43396) was used.

[0264] The results of a scanning electron microscope (SEM) cross-sectional analysis of the membrane-electrode assembly manufactured in Comparative Example 1 are shown in Fig. 10.

[0265]

[0266] Evaluation Example 1. Measurement of the area of ​​the coating layer compared to the total area of ​​the catalyst for oxygen generation reaction.

[0267] In Manufacturing Examples 1 and 2, the area of ​​the coating layer was measured by measuring the area of ​​the first ion conductor coated on the surface of 100 randomly selected catalysts in the TEM image, and the area of ​​the coating layer was taken as the average value of the 100 areas.

[0268]

[0269] Evaluation Example 2. Measurement of Dispersion Stability

[0270] The evaluation of the dispersion stability of the catalyst for oxygen generation reaction according to Manufacturing Examples 1 and 2 and Comparative Example 1 was conducted using the following method.

[0271] As a catalyst for oxygen evolution reaction, 1 g of each of the oxygen evolution reaction catalysts (A) and (B) coated with the first ion conductor of Manufacturing Examples 1 and 2 and the commercial IrOx / TiO2 (Alfa Aesar, 43396) of Comparative Example 1 was added to manufacture an electrode, and after centrifugation at 10,000 rpm for 10 minutes and 30 minutes using a centrifuge device, the solution was extracted at the middle point of the solution and the solid content reduction amount was measured through solid content analysis.

[0272] The results of evaluating the dispersion stability of the manufacturing examples and comparative examples according to the above method are shown in Table 1.

[0273] Manufacturing Example 1 Manufacturing Example 2 Comparative Example 1 10 minutes processing 5% 9% 11% 30 minutes processing 12% 19% 25%

[0274] As shown in Table 1 above, it can be confirmed that Manufacturing Examples 1 and 2, in which a coating layer was formed on the surface of the oxygen generation reaction catalyst, have superior dispersion stability compared to the comparative examples in which a coating layer was not formed, and it can be confirmed that Manufacturing Example 1, in which the area of ​​the coating layer was 85% on average compared to the entire surface of the oxygen generation reaction catalyst, has superior dispersion stability compared to Manufacturing Example 2, in which the area was 50% on average.

[0275] Evaluation Example 3. IV Characteristics

[0276] The membrane-electrode assembly manufactured in Examples 1 to 3 and Comparative Example 1 was applied inside a unit cell designed and manufactured for use in a water electrolysis cell, and a protocol for measuring voltage and resistance at a specific current from 1 mA to 20 A was applied under the conditions of a cell temperature of 80°C, a water temperature of 80°C, and a flow rate of 5 ml / min, and the measurement was stopped at 2 V.

[0277] The results at this time are shown in Fig. 11.

[0278]

[0279] Evaluation Example 4. Durability Evaluation

[0280] The membrane-electrode assembly manufactured in Examples 1-1 to 3 and Comparative Example 1 was applied inside a unit cell designed and manufactured for a water electrolysis cell, and the cell temperature was 80°C, and the current density was 1 A / cm. 2 After driving the constant current for 500 hours, the voltage increase rate was measured.

[0281] The above voltage was measured using a potentiostat from BioLogic, and the voltage increase rate was calculated using the measured voltage according to Equation 1 below. The results at this time are as shown in Table 2 below.

[0282] [Formula 1]

[0283] Voltage increase rate (%) = (voltage after operation - initial voltage) / (initial voltage) × 100

[0284] Example 1-1 Example 1-2 Example 2-1 Example 2-2 Example 3 Comparative Example 1 Voltage increase rate (%) 5.6 2.2 5.8 3.5 10.2 16.2

[0285] As shown in Table 2 above, the membrane-electrode assemblies according to Examples 1-1 to 3 exhibited chemical durability with less voltage loss than the membrane-electrode assembly according to Comparative Example 1. According to Examples 1-1 and 3, it can be confirmed that the greater the area of ​​the coating layer coated with the first ion conductor relative to the entire surface of the catalyst for oxygen evolution reaction, the less durability with voltage loss was exhibited.

[0286]

[0287] Although the preferred embodiments have been described in detail above, the scope of the rights is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the rights.

[0288] [Explanation of symbols]

[0289] 1: Polymer electrolyte membrane

[0290] 2: Catalyst for oxygen generation reaction coated with first ion conductor

[0291] 3: Second ionic conductor

[0292] 4: Composition for forming a catalyst layer

[0293] 5: Ion conductor rich layer

[0294] 6: Description

Claims

1. Polymer electrolyte membrane; and An oxygen generation electrode positioned on one side of the polymer electrolyte membrane and including a catalyst layer for oxygen generation reaction; and A hydrogen generation electrode positioned on the other side of the polymer electrolyte membrane; The above-mentioned catalyst layer for oxygen generation reaction is, A catalyst for oxygen evolution reaction comprising active particles comprising a first precious metal oxide; A coating layer that coats the surface of the oxygen generation reaction catalyst and includes a first ion conductor; and A membrane-electrode assembly for a water electrolysis cell, comprising a second ion conductor that is not coated on the surface of the oxygen generation reaction catalyst.

2. In paragraph 1, The above first noble metal oxide is IrO x (wherein x is an integer from 1 to 3), RuO x (where x is an integer from 1 to 3), IrMO x (wherein M comprises Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au, or a combination thereof, and x is an integer from 1 to 3), or a combination thereof. A membrane-electrode assembly for a water electrolysis cell.

3. In paragraph 1, The above oxygen generation reaction catalyst further includes a carrier that supports the active particles, A membrane-electrode assembly for a water electrolysis cell, wherein the carrier comprises a second noble metal oxide different from the first noble metal oxide.

4. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the area of ​​the coating layer is 30% or more of the total surface area of ​​the oxygen generation reaction catalyst.

5. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the thickness of the coating layer is in the range of 1 nm to 15 nm.

6. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the first ion conductor is included in an amount of 3 to 50 parts by weight relative to 100 parts by weight of the oxygen generation reaction catalyst.

7. In paragraph 1, The first ion conductor and the second ion conductor each independently include a fluorine-based ion conductor, a hydrocarbon-based ion conductor, or a combination thereof. A membrane-electrode assembly for a water electrolysis cell, wherein the first ion conductor and the second ion conductor are the same or different.

8. In paragraph 1, The equivalent weight (EW) of the first ion conductor and the second ion conductor are each independently within a range of 600 g / eq to 1100 g / eq, A membrane-electrode assembly for a water electrolysis cell, wherein the equivalent weights of the first ion conductor and the equivalent weights of the second ion conductor are different from each other.

9. In paragraph 1, One of the first ion conductor and the second ion conductor is a fluorine-based ion conductor and the other is a hydrocarbon-based ion conductor; or The first ion conductor is a first hydrocarbon-based ion conductor, and the second ion conductor is a second hydrocarbon-based ion conductor different from the first hydrocarbon-based ion conductor; or A membrane-electrode assembly for a water electrolysis cell, wherein the first ion conductor is a first fluorine-based ion conductor, and the second ion conductor is a second fluorine-based ion conductor different from the first fluorine-based ion conductor.

10. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the second ion conductor is included in an amount of 20 to 80 parts by weight based on 100 parts by weight of the total content of the first ion conductor and the second ion conductor included in the oxygen generation reaction catalyst layer.

11. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the catalyst layer for the oxygen generation reaction further includes a functional additive including a radical scavenger, a gas barrier particle, a hydrophilic inorganic additive, a heat-dissipating material, or a combination thereof.

12. In paragraph 11, A membrane-electrode assembly for a water electrolysis cell, wherein the functional additive is included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the second ion conductor.

13. In paragraph 1, The membrane-electrode assembly for the above-mentioned water electrolysis cell is, Located between the above oxygen generation reaction catalyst layer and the above polymer electrolyte membrane, A membrane-electrode assembly for a water electrolysis cell further comprising an ionomer-rich layer comprising the second ion conductor.

14. In paragraph 1, The above hydrogen generation electrode is, A membrane-electrode assembly for a water electrolysis cell, comprising a carbon-based carrier and a hydrogen-generating catalyst supported on the carbon-based carrier and including active particles including a precious metal.

15. In paragraph 1, A membrane-electrode assembly for a water electrolysis cell, wherein the polymer electrolyte membrane comprises a porous support including a plurality of pores, and an ion conductor filling the pores of the porous support.

16. A step (S1) of manufacturing an oxygen generation reaction catalyst coated with the first ion conductor by mixing the oxygen generation reaction catalyst and the first ion conductor and then performing a heat treatment; Step (S2) of preparing a composition for forming a catalyst layer by adding a catalyst for oxygen generation reaction coated with the first ion conductor and a second ion conductor to a solvent; and It includes a step (S3) of forming a catalyst layer for oxygen generation reaction on at least one side of a polymer electrolyte membrane using the composition for forming the catalyst layer. The above oxygen generation reaction catalyst comprises active particles including a first noble metal oxide, A method for manufacturing a membrane-electrode assembly for a water electrolysis cell, wherein the oxygen evolution reaction catalyst coated with the first ion conductor comprises the oxygen evolution reaction catalyst and a coating layer that coats the surface of the oxygen evolution reaction catalyst and includes the first ion conductor.

17. In paragraph 16, In the above step S1, A method for manufacturing a membrane-electrode assembly for a water electrolysis cell, wherein the above heat treatment is performed at a temperature in the range of 110°C to 220°C for 1 to 4 hours.

18. In paragraph 16, In the above step S3, Forming the catalyst layer for the above oxygen generation reaction is as follows: The composition for forming the catalyst layer is directly coated on the polymer electrolyte membrane, or The composition for forming the catalyst layer is coated on a substrate to form a catalyst layer for oxygen generation reaction, and then the catalyst layer for oxygen generation reaction is transferred to the polymer electrolyte membrane. A method for manufacturing a membrane electrode assembly for a water electrolysis cell.

19. In Article 16, After the above S3 step, Including an additional drying step, The above drying step is performed at a temperature in the range of 60°C to 110°C for 3 to 50 minutes, A method for manufacturing a membrane-electrode assembly for a water electrolysis cell, wherein, in the drying step, the second ion conductor that is not coated on the surface of the oxygen generation reaction catalyst precipitates toward the polymer electrolyte membrane to form an ion conductor-rich layer.

20. A water electrolysis cell comprising a membrane electrode assembly according to paragraph 1.

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