Electrolyte membrane for fuel cells comprising a catalytic composite with improved oxygen permeability and method for its preparation

Abstract

Disclosed is an electrolyte membrane for a fuel cell including a catalytic composite having improved oxygen permeability and a method for preparing the same, the electrolyte membrane including a catalytic composite including catalytic particles coated with an oxygen permeable material. The electrolyte membrane for a fuel cell includes an ion transport layer of an ionomer having proton conductivity and a catalytic composite dispersed in the ion transport layer, the catalytic composite including catalytic particles having a catalytic metal component having activity to decompose hydrogen peroxide and a coating layer formed on at least a portion of the surface of the catalytic particles and including an oxygen permeable material.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrolyte membrane for a fuel cell including a catalytic composite including catalytic particles coated with an oxygen-permeable material, and a manufacturing method thereof. BACKGROUND

[0002] A fuel cell commonly used for vehicles is a polymer electrolyte membrane fuel cell (PEMFC). In order for polymer electrolyte membrane fuel cells to normally exert a high power of at least several tens of kilowatts or more, they should be able to stably operate over a wide current density range.

[0003] A power generation reaction of a fuel cell occurs in a membrane electrode assembly (MEA) including a perfluorosulfonic acid (PFSA) ionomer-based membrane and a pair of electrodes, i.e., an anode and a cathode. Hydrogen supplied to the anode (as an oxidation electrode) is decomposed into protons and electrons, and then the protons move through the membrane to a reduction electrode (i.e., the cathode), and the electrons move to the cathode through an external circuit. Then, at the cathode, oxygen molecules, protons, and electrons react with each other to generate electricity, while water (H2O) and heat are produced as byproducts.

[0004] Hydrogen and oxygen are reaction gases of a fuel cell, and can move across through an electrolyte membrane. In this process, hydrogen peroxide (HOOH) can be generated. When hydrogen peroxide is decomposed into oxygen-containing radicals such as a hydroxyl radical (·OH) and a hydroperoxyl radical (·OOH), these radicals corrode the electrolyte membrane, causing chemical degradation of the electrolyte membrane, which eventually results in an undesirable effect of reducing the durability of the fuel cell.

[0005] As a method of mitigating such chemical degradation of the electrolyte membrane, a method of adding various antioxidants to the electrolyte membrane has been proposed. The antioxidants include a primary antioxidant that functions as a radical scavenger or a quencher, a secondary antioxidant that functions as a hydrogen peroxide decomposer, and the like.

[0006] Examples of representative primary antioxidants for polymer electrolyte membrane fuel cells include cerium-based antioxidants (e.g., cerium oxide (ceria) and cerium (III) nitrate hexahydrate antioxidants), terephthalate-based antioxidants, and the like.

[0007] Broadly, cerium oxide can include pure cerium oxide (CeO2) and modified cerium oxide (modified CeO2). The modified cerium oxide includes: cerium-zirconium oxide (CeZrO x ), cerium-manganese oxide (CeMnO x ), silica-doped cerium oxide, yttria-doped cerium oxide, zirconia-doped cerium oxide, and the like.

[0008] Meanwhile, representative co-antioxidants for electrolyte membranes include manganese-based catalysts (e.g., manganese oxide) and noble metal catalysts (e.g., platinum (Pt)). Recently, various studies have been conducted on the addition of platinum catalysts to electrolyte membranes for fuel cells.

[0009] The results of the studies conducted thus far indicate that the durability of electrolyte membranes increases or decreases depending on the amount of platinum introduced into the electrolyte membranes, the degree of distribution thereof, and the microstructure. First, one positive effect is that the platinum introduced into the electrolyte membranes converts the cross-over hydrogen and oxygen into water before the gases reach the electrodes, thereby increasing the amount of water in the electrolyte membranes, improving the proton conductivity, and ultimately improving the performance of the membrane electrode assembly. In addition, another positive effect is that the platinum prevents the cross-over of hydrogen and oxygen to prevent the generation of free radicals, or decomposes the hydrogen peroxide generated in the electrolyte membranes, thereby improving the chemical durability of the electrolyte membranes. On the other hand, a negative effect is that the platinum introduced into the electrolyte membranes converts the hydrogen peroxide into free radicals, or directly converts the cross-over oxygen into free radicals, resulting in a decrease in the durability of the electrolyte membranes. Therefore, in order to improve the chemical durability of the electrolyte membranes by applying platinum to the electrolyte membranes, it is important to understand the mechanism of action of platinum in the electrolyte membranes and to propose an appropriate solution.

[0010] In order to effectively remove the cross-over hydrogen and oxygen in the electrolyte membranes, the cross-over hydrogen and oxygen should meet the hydrogen peroxide decomposition catalyst together. However, since the electrolyte membranes are substantially gas-occlusive, it is difficult to determine and control the flow of the cross-over gases. However, as described above, since the cross-over gases can react with the hydrogen peroxide decomposition catalyst in the electrolyte membranes or thus be decomposed, or can move to the electrodes to generate hydrogen peroxide, in order to prevent the cross-over gases from reaching the electrodes, the cross-over gases should be decomposed as much as possible by the hydrogen peroxide decomposition catalyst in the electrolyte membranes.

[0011] The above information disclosed in this Background section is only for understanding of the background of the present application, and therefore it can contain information that does not constitute prior art that is already known in this country to a person of ordinary skill in the art. SUMMARY

[0012] In preferred aspects, there is provided, inter alia, an electrolyte membrane that can greatly improve the chemical durability by allowing hydrogen and oxygen to cross over through the electrolyte membrane so as to easily reach the catalytic metal contained in the electrolyte membrane and thus be decomposed by the catalytic metal.

[0013] In one aspect, an electrolyte membrane for a fuel cell is provided, the electrolyte membrane comprising an ion transport layer, the ion transport layer comprising (i) an ionomer having proton conductivity and (ii) a catalytic composite. The catalytic composite comprises a catalytic particle comprising a catalytic metal component having activity to decompose hydrogen peroxide and a coating formed on at least a portion of a surface of the catalytic particle and comprising an oxygen permeable material. In certain preferred aspects, the catalytic composite can be dispersed (e.g., substantially randomly dispersed or in an ordered manner) in the ion transport layer.

[0014] The ionomer can suitably comprise a perfluorinated sulfonic acid ionomer.

[0015] The catalytic particle can suitably comprise a catalytic metal component without a support. Alternatively, the catalytic particle can suitably comprise a catalytic metal component supported on a support.

[0016] The catalytic metal component can comprise, for example, one or more selected from the group consisting of platinum (Pt), gold (Au), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), and ruthenium (Ru). The catalytic metal component can be supported on a support comprising one or more selected from the group consisting of carbon; silicon dioxide; a zeolite; a transition metal selected from Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal.

[0017] The coating can be formed on at least a portion of a surface of the catalytic metal component of the surface of the catalytic particle.

[0018] The oxygen permeable material can conduct ions.

[0019] The oxygen permeable material can be compatible with the ionomer.

[0020] The oxygen permeable material can have an oxygen permeability greater than that of the ionomer.

[0021] The material can suitably comprise a perfluorinated sulfonic acid ionomer having an oxygen permeability of about 3.0 x 10 -9 cc-cm / (cm 2 sec-cmHg) or greater, when measured at any point in a temperature range of about 30°C to 150°C and a relative humidity range of about 20% to 100%.

[0022] The electrolyte membrane can suitably comprise the catalytic composite in an amount of about 0.01 mg / cm 2 to 0.90 mg / cm 2 .

[0023] The electrolyte membrane can further comprise a reinforcing layer, and the ion transport layer can be formed on at least one surface of the reinforcing layer.

[0024] A method of manufacturing an electrolyte membrane for a fuel cell is provided. The method can include: preparing a catalytic composite including catalytic particles and an oxygen permeable material, the catalytic particles including a catalytic metal component having activity to decompose hydrogen peroxide, such that a coating layer including the oxygen permeable material is formed on at least a portion of a surface of the catalytic particles; preparing a dispersion mixture including the catalytic composite and an ionomer, and applying the dispersion mixture to form an ion transport layer.

[0025] Preparation of the catalytic composite can include drying a mixture including the catalytic particles and the oxygen permeable material at a temperature of about 80°C to 200°C.

[0026] The catalytic particles can include the catalytic metal component without a support, or can include the catalytic metal component supported on a support.

[0027] The catalytic metal can include one or more selected from the group consisting of platinum (Pt), gold (Au), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), and ruthenium (Ru). The support includes one or more selected from the group consisting of carbon; silicon dioxide; zeolite; a transition metal selected from the group consisting of Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal.

[0028] The oxygen permeable material can be capable of conducting ions, can be compatible with the ionomer, and can have a greater oxygen permeability than the ionomer.

[0029] The material can include a perfluorinated sulfonic acid ionomer having an oxygen permeability of about 3.0 x 10 - 9 cc·cm / (cm 2 ·sec·cmHg) or more.

[0030] The ionomer can suitably include a perfluorinated sulfonic acid ionomer.

[0031] The ion transport layer can be formed by applying a dispersion on at least one surface of the reinforcing layer.

[0032] Further provided is a fuel cell for a vehicle including the electrolyte membrane described herein.

[0033] Other aspects of the present application are discussed below. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and other features of the present application will now be described in detail with reference to certain example embodiments thereof, which are illustrated in the accompanying drawings, wherein:

[0035] Figure 1 is a cross-sectional view schematically showing an example membrane electrode assembly according to an example embodiment of the present application.

[0036] Figure 2 shows an example electrolyte membrane according to an example embodiment of the present application;

[0037] Figure 3A shows an example catalytic composite according to an example embodiment of the present application;

[0038] Figure 3B shows an example catalytic composite according to an example embodiment of the present application;

[0039] Figure 4 shows the flow of oxygen across the electrolyte membrane without a coating.

[0040] Figure 5 shows the flow of oxygen across the example electrolyte membrane when a coating is formed according to an example embodiment of the present application; and

[0041] Figures 6 to 8 shows a modified electrolyte membrane according to an example embodiment of the present application. DETAILED DESCRIPTION

[0042] The above and other objects, features and advantages of the present application will be more clearly understood from the following preferred embodiments taken in conjunction with the accompanying drawings. However, the present application is not limited to the embodiments but can be embodied in various different forms. The proposed embodiments are merely for the thorough and complete disclosure of the present application and to fully convey the technical spirit of the present application to those skilled in the art.

[0043] Throughout the drawings, like reference numerals will be used to designate like elements. In the drawings, the dimensions of structures are exaggerated for clarity. It will be understood that, although the terms first, second, etc. can be used herein to describe various elements, these elements should not be limited by these terms since such elements are commonly known to one of ordinary skill in the art. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0044] It will be further understood that the terms "comprises" "comprising", "includes" and / or "including", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. In addition it will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it will be understood that when an element such as a layer, film, region or substrate is referred to as being "under" another element, it can be directly under the other element, or intervening elements can also be present.

[0045] Unless otherwise defined, all numbers, numerical expressions, and / or terms expressing quantities of ingredients, reaction conditions, polymer compositions, and / or amounts of the components or mixtures herein are to be understood as approximations based on the inherent variability of measurements actually made. Because of this inherent variability, it is understood that the terms "about" and "substantially" can be utilized in describing the numerical values, numbers, and / or expressions. Moreover, unless specifically stated otherwise, the terms "about" and "substantially" are understood to be within the normal

[0046] In addition, where a range of values is disclosed, unless otherwise defined, the range is a continuous range including all values from the minimum to the maximum value. In addition, where a range of values is stated as being "between" a minimum and a maximum value, unless otherwise defined, it is intended that the range of values include the maximum and minimum values.

[0047] It is to be understood that the terms "vehicle" or "vehicular" or other similar terms as used herein generally include motor vehicles such as passenger cars, sport utility vehicles (SUVs), trucks, various commercial vehicles, including passenger automobiles, boats, ships, aircraft, etc., and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., those powered by fuels other than petroleum products). As used herein, a hybrid vehicle is a vehicle having two or more power sources, such as a gasoline-powered vehicle and an electric-powered vehicle.

[0048] Figure 1 is an exemplary cross-sectional view schematically illustrating an exemplary membrane electrode assembly (MEA) 10 according to an exemplary embodiment of the present application. As shown in FIG. 1, the MEA 10 includes a cathode 12, an anode 14, and a polymer electrolyte membrane 16 disposed between the cathode 12 and the anode 14. The cathode 12 includes a cathode catalyst layer 18, a cathode diffusion layer 20, and a cathode current collector 22. The anode 14 includes an anode catalyst layer 24, an anode diffusion layer 26, and an anode current collector 28. The cathode catalyst layer 18 and the anode catalyst layer 24 are disposed on opposite sides of the polymer electrolyte membrane 16. The cathode catalyst layer 18 and the anode catalyst layer 24 are each formed of a catalyst material, such as platinum or platinum alloy. The polymer electrolyte membrane 16 is formed of a polymer electrolyte material, such as a perfluorosulfonic acid polymer. Figure 1As shown, the membrane electrode assembly 10 includes a cathode 100, an anode 200, and an electrolyte membrane 300 interposed therebetween.

[0049] The cathode 100 is a component that reacts with oxygen in the air, and the anode 200 is a component that reacts with hydrogen. The anode 200 decomposes hydrogen into hydrogen ions (protons) and electrons through a hydrogen oxidation reaction (HOR). The hydrogen ions move to the cathode 100 through the electrolyte membrane 300 in contact with the anode 200. The electrons move to the cathode 100 through an external wire (not shown).

[0050] The cathode 100 and the anode 200 can include a catalyst, such as carbon-supported Pt. The cathode 100 and the anode 200 can also include an ionomer (or binder) for proton conduction.

[0051] Figure 2 An electrolyte membrane 300 according to an exemplary embodiment of the present application is shown. As shown, the electrolyte membrane 300 includes an ion transport layer 400 and a plurality of catalytic composites 500 dispersed in the ion transport layer 400. Figure 2

[0052] The ion transport layer 400 can include an ionomer having hydrogen ion (proton) conductivity. The ionomer can suitably include any material capable of transferring protons. For example, the ionomer can include a perfluorinated sulfonic acid ionomer (PFSA).

[0053] Figure 3A An example of each catalytic composite 500 is shown. As shown, the catalytic composite 500 includes a catalytic particle 510 and a coating layer 520 formed on at least a portion of a surface of the catalytic particle 510. Figure 3A Figure 3A It is shown that the coating layer 520 completely coats the catalytic particle 510. However, this is for better understanding of the present application, and thus the catalytic composite 500 should not be construed as being limited to the shape shown. For example, the coating layer 520 surrounds at least about 1%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or about 100% of a surface area of the catalytic particle 510. Figure 3A

[0054] Another example of the catalytic composite 500 is shown. As shown, the catalytic particle 510 can include only a catalytic metal component 511 without a support, and the coating layer 520 can be formed on at least a portion of a surface of each catalytic particle 510. Figure 3B Figure 3B

[0055] ​​​​Hereinafter, it is assumed for the convenience of description that the catalytic particle 510 has a structure in which the catalytic metal component 511 is supported on the carrier 512. However, it should also be explained that the scope of the present application includes catalytic particles 510 that do not have such a carrier 512.

[0056] The catalytic metal component 511 is a metal having an activity of decomposing hydrogen peroxide, which can include one or more selected from the group consisting of platinum (Pt), gold (Au), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), and ruthenium (Ru).

[0057] The carrier 512 is not particularly limited, and can include one or more selected from the group consisting of carbon; silicon dioxide; zeolite; a transition metal selected from the group consisting of Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal.

[0058] The carrier 512 can preferably have a large specific surface area. As described above, a catalyst can also be added to the cathode 100 and / or the anode 200. The carrier 521 according to the present application can have a larger specific surface area than a carrier for a catalyst of an electrode as described above. For example, a carrier for an electrode should have a high degree of graphitization to withstand carbon corrosion that occurs rapidly when the electrode is exposed to a high voltage of greater than 1 V. However, since there is a trade-off between the degree of graphitization and the specific surface area, it is not easy in practice to obtain a carrier having a high degree of graphitization and a large specific surface area. Since the carrier only needs to withstand a voltage difference of about 0 to about 1 V, preferably, a carrier having a high specific surface area can be used without considering the degree of graphitization. The specific surface area of the carrier 512 according to the present application is about 100 m 2 / g to 3,000 m 2 / g, about 500 m 2 / g to 3,000 m 2 / g, or particularly about 800 m 2 / g to 3,000 m 2 / g. Thus, the carrier 512 can support a large amount of the catalytic metal component.

[0059] In addition, the carrier 512 can have an average particle diameter of about 10 nm to 10 μm. The average particle diameter can be measured using a commercially available laser diffraction scattering particle size distribution analyzer, such as a Microtrack particle size distribution measuring device. In addition, the average particle diameter can be calculated from 200 particles randomly extracted from an electron microscope photograph.

[0060] The catalytic composite 500 according to the present application includes a coating layer 520 including an oxygen-permeable material and formed on at least a part of the surface of the catalytic particle 510.

[0061] Figure 4Oxygen flow across the exemplary electrolyte membrane 300 is shown when the coating 520 is not present. Figure 5 The flow of oxygen across the exemplary electrolyte membrane 300 is shown when forming the coating layer 520 according to an exemplary embodiment of the present invention.

[0062] like Figure 4 As shown, in the absence of the coating 520, oxygen that crosses the electrolyte membrane may not reach the catalytic metal component 511 and may move to the electrode. Figure 5 As shown, since the gas permeability around the catalytic metal component 511 is greater than the gas permeability around the ion transport layer 400 , the flow of oxygen is induced, and thus oxygen can easily reach the catalytic metal component 511 .

[0063] As described above, the coating layer 520 may include an oxygen permeable material. In addition, the coating layer 520 may be formed on at least a portion of the surface of the catalytic particle 510 , or in particular, on at least a portion of the surface of the catalytic metal component 511 .

[0064] The material is not particularly limited, but its oxygen permeability may be greater than that of the ionomer included in the ion transport layer 400. For example, the material may have an oxygen permeability of 3.0×10 -9 cc·cm / (cm 2 ·sec·cmHg) or greater, or approximately 5.0x10 -9 cc·cm / (cm 2 ·sec·cmHg) or greater, or approximately 5.0x10 -9 cc·cm / (cm 2 ·sec·cmHg) or greater oxygen permeability. The oxygen permeability of the material may preferably be about 3.0×0 -9 cc·cm / (cm 2 ·sec·cmHg) or more so that the cross-migrated oxygen can easily reach the catalytic metal component 511 as described above, thereby being decomposed.

[0065] The oxygen permeability may be measured according to JIS K7126-2 and ISO 15105-2, and may be specifically calculated according to the following Formula 1.

[0066] [Formula 1]

[0067] P = (X × k × T / (A × D × p))

[0068] Where P is the oxygen permeability [cc·cm / (cm 2[cc], k is a correction factor, T is the thickness of the membrane [cm], A is the permeation area [cm 2 ] D is the tube passing time [sec], and p is the oxygen partial pressure [cmHg].

[0069] The material can be ionically conductive and can be compatible with the ionomer that constitutes the ion transport layer 400. Here, the term "compatible" means that when two substances are mixed, they are homogenized at the molecular level due to the same or similar chemical properties between them, and thus neither phase separation nor interface formation occurs.

[0070] Therefore, preferably, the material satisfies the oxygen permeability rate described above and has the same or similar chemical properties as the ionomer. For example, the material can suitably include a perfluorinated sulfonic acid polymer.

[0071] The electrolyte membrane 300 can suitably include the catalytic composite 500 in an amount of about 0.01 mg / cm 2 to 0.90 mg / cm 2 or about 0.05 mg / cm 2 to 0.40 mg / cm 2 When the content of the catalytic composite 500 is too low, the effect of increasing the chemical durability of the electrolyte membrane can not be significant. On the other hand, when the content is too high, the cost can greatly increase, and it can be difficult to ensure electrical insulation in the electrolyte membrane.

[0072] Figures 6 to 8 A modified structure of the electrolyte membrane 300 according to the present application is shown.

[0073] The electrolyte membrane 300 can include a reinforcing layer 600 and an ion transport layer 400 formed on at least one surface of the reinforcing layer 600.

[0074] The reinforcing layer 600 is a component for improving the mechanical strength (rigidity) of the electrolyte membrane 300. The reinforcing layer 600 can suitably include one or more selected from polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (e-PTFE), polyethylene (PE), polypropylene (PP), polyphenylene ether (PPO), polybenzimidazole (PBI), polyimide (PI), polyvinylidene fluoride (PVdF), and polyvinyl chloride (PVC), and can be a porous membrane having a large number of pores.

[0075] The reinforcing layer 600 can be porous and can be impregnated with an ionomer as described above.

[0076] As Figure 6As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600.

[0077] As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600. Figure 7 As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600.

[0078] As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600. Figure 8 As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600.

[0079] Figures 6 to 8 The various embodiments of the electrolyte membrane 300 according to the exemplary embodiments of the present application are merely illustratively shown, but this does not limit the scope of the electrolyte membrane 300. That is, any structure other than the structure shown in Figures 6 to 8 As shown, the electrolyte membrane 300 can include an ion transport layer 400 including the catalytic composite 500 on one surface of the reinforced layer 600 impregnated with the ionomer and another ionomer layer 700' on the other surface of the reinforced layer 600.

[0080] In one aspect, a method of manufacturing an electrolyte membrane 300 can include the steps of: preparing a catalytic composite 500 including catalytic particles 510 including a catalytic metal component having activity of decomposing hydrogen peroxide and an oxygen permeable material, such that a coating layer containing the oxygen permeable material is formed on at least a part of a surface of the catalytic particles; preparing a dispersion mixture containing the catalytic composite 500 and an ionomer, and applying the dispersion to form an ion transport layer 400.

[0081] Details of the respective components of the catalytic particles 510, the oxygen permeable material, the catalytic composite 500, etc. have been described above, and will be omitted hereinafter.

[0082] The catalytic composite 500 is prepared by drying a mixture obtained by mixing the catalytic particles with the above-described material at a temperature of about 80 to 200°C. In this case, the mixture can be prepared by adding the catalytic particles and the above-described material to a solvent and then stirring. When the drying temperature of the mixture is less than about 80°C, the solvent cannot be sufficiently evaporated, so it is difficult to powderize the catalytic composite 500, and when the temperature is higher than about 200°C, the material can be pyrolyzed.

[0083] The method of applying the dispersion mixture is not particularly limited. For example, the dispersion mixture can be applied by screen printing, spraying, coating using a doctor blade, gravure coating, dip coating, screen printing, painting, coating using a slit die, or the like.

[0084] As described above, the electrolyte membrane 300 can include the reinforcing layer 600.

[0085] Figure 6 The electrolyte membrane 300 illustrated can be manufactured by an exemplary method including applying a solution of ionomer to a substrate, supplying a porous reinforcing layer 600 to the solution of ionomer to impregnate the reinforcing layer 600 with the ionomer to form an ionomer layer 700, applying a dispersion mixture to one surface of the reinforcing layer 600 opposite the ionomer layer 700 to form an ion transport layer 400, and performing drying and heat treatment. However, the manufacturing method is not limited thereto, and can be performed by appropriately modifying the specific means such as the order and application of each step. In addition, the electrolyte membrane 300 can be manufactured by other methods such as impregnation and transfer, and application. This also applies to the case of other manufacturing methods described later.

[0086] Drying after forming the ion transport layer 400 can be performed at a temperature of about 100°C or less for about 30 minutes or more. When the drying temperature is greater than about 100°C, the ionomer can be pyrolyzed. On the other hand, when the drying time is less than about 30 minutes, the drying can be insufficient.

[0087] Heat treatment can be performed at a temperature of about 110°C or more for about 20 minutes or less. When the heat treatment time is too long, the ionomer can be pyrolyzed.

[0088] Figure 7 The electrolyte membrane 300 illustrated can be manufactured by a method including supplying a porous reinforcing layer 600 to a dispersion mixture to impregnate the reinforcing layer 600 with ionomer to form one ion transport layer 400', applying a dispersion to one surface of the reinforcing layer 600 opposite the ion transport layer 400' to form another ion transport layer 400, and performing drying and heat treatment.

[0089] Figure 8 The electrolyte membrane 300 illustrated can be manufactured by a method including supplying a porous reinforcing layer 600 to a solution of ionomer to impregnate the reinforcing layer 600 with ionomer to form one ionomer layer 700', applying ionomer to one surface of the reinforcing layer 600 opposite the ionomer layer 700' to form another ionomer layer 700, applying a dispersion mixture to the ionomer layer 700 to form an ion transport layer 400, and performing drying and heat treatment.

[0090] The method can include adding the catalytic particles containing the first metal and the second metal as described above to the ionomer solution and dispersing the same in the ionomer solution, applying the resulting product to the reinforcement layer impregnated with the ionomer, and performing drying and heat treatment. However, the manufacturing method is not limited thereto, and the specific means such as the order of the respective steps or the application thereof can be appropriately modified. In addition, the electrolyte membrane 300 can be manufactured by other methods such as impregnation and transfer, and application. This also applies to other manufacturing methods described later.

[0091] The electrolyte membrane 300 according to the present application and the manufacturing method thereof have been described above. The key feature of the present application is to inject the catalytic particles 510 containing the catalytic metal component 511 having the activity of decomposing hydrogen peroxide into the electrolyte membrane 300, and a coating layer 520 containing an oxygen permeable material can be formed on the surface of the catalytic particles 510, so that oxygen gas crossing through the electrolyte membrane 300 can easily reach the catalytic metal component 511. It is obvious that other embodiments designed or modified according to the various exemplary embodiments described above can be easily derived from the present application, and fall within the scope of the present application, as long as these embodiments have the purposes and effects described above.

[0092] As obvious from the foregoing, since hydrogen gas and oxygen gas crossing through the electrolyte membrane can more easily reach the catalytic metal component contained in the electrolyte membrane, the electrolyte membrane according to the present application can show improved chemical durability.

[0093] Since no additional additives are added to the electrolyte membrane, the electrolyte membrane according to the various exemplary embodiments of the present application can show greatly improved chemical durability without reducing the performance of the electrolyte membrane.

[0094] The effects of the present application are not limited to the above-described effects. It should be understood that the effects of the present application include all effects that can be inferred from the foregoing description of the present application.

[0095] The present application has been described in detail with reference to the preferred embodiments. However, those skilled in the art will appreciate that changes can be made in these embodiments without departing from the principles and spirit of the present application, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An electrolyte membrane for a fuel cell, comprising: an ion transport layer comprising (i) an ionomer having proton conductivity and (ii) a catalytic composite dispersed in the ion transport layer, wherein the catalytic composite comprises: a catalytic particle comprising a catalytic metal component having an activity to decompose hydrogen peroxide; and a coating layer formed on at least a part of a surface of the catalytic particle and comprising an oxygen permeable material, wherein the oxygen permeable material has an oxygen permeability greater than that of the ionomer, The oxygen permeable material comprises a perfluorinated sulfonic acid ionomer having an oxygen permeability of 3.0 x 10 -9 cc-cm / (cm 2 ·sec-cmHg) or more, when measured at any point within a temperature range of 30°C to 150°C and a relative humidity range of 20% to 100%. The oxygen permeable material comprises a perfluorinated sulfonic acid ionomer having an oxygen permeability of 3.0 x 10 -9 cc-cm / (cm 2 ·sec-cmHg) or more, when measured at any point within a temperature range of 30°C to 150°C and a relative humidity range of 20% to 100%. The electrolyte membrane comprises a catalytic complex in an amount of 0.01 mg / cm 2 to 0.90 mg / cm 2 of the membrane.

2. The electrolyte membrane for a fuel cell according to claim 1, wherein, the catalytic particle comprises the catalytic metal component without a support.

3. The electrolyte membrane for a fuel cell according to claim 1, wherein, the catalytic particle comprises the catalytic metal component supported on a support.

4. The electrolyte membrane for a fuel cell according to claim 1, wherein, the catalytic metal component comprises one or more selected from the group consisting of platinum, gold, palladium, silver, osmium, iridium, and ruthenium, and the catalytic metal component is supported on a support comprising one or more selected from the group consisting of carbon; silica; a zeolite; a transition metal selected from Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal.

5. The electrolyte membrane for a fuel cell according to claim 1, wherein, the coating layer is formed on at least a part of a surface of the catalytic metal component on a surface of the catalytic particle.

6. The electrolyte membrane for a fuel cell according to claim 1, wherein the oxygen permeable material is compatible with the ionomer.

7. The electrolyte membrane for a fuel cell according to claim 1, wherein, the electrolyte membrane further comprises a reinforcing layer, wherein the ion transport layer is formed on at least one surface of the reinforcing layer.

8. A method of manufacturing an electrolyte membrane for a fuel cell, the method comprising: preparing a catalytic composite comprising a catalytic particle and an oxygen permeable material, the catalytic particle comprising a catalytic metal component having an activity to decompose hydrogen peroxide, such that a coating layer comprising the oxygen permeable material is formed on at least a part of a surface of the catalytic particle; preparing a dispersion mixture comprising the catalytic composite and an ionomer; and applying the dispersion mixture to form an ion transport layer, wherein the oxygen permeable material has an oxygen permeability greater than that of the ionomer, The oxygen permeable material comprises a perfluorinated sulfonic acid ionomer having an oxygen permeability of 3.0 x 10 -9 cc-cm / (cm 2 ·sec-cmHg) or more, when measured at any point within a temperature range of 30°C to 150°C and a relative humidity range of 20% to 100%. The oxygen permeable material comprises a perfluorinated sulfonic acid ionomer having an oxygen permeability of 3.0 x 10 -9 cc-cm / (cm 2 ·sec-cmHg) or more, when measured at any point within a temperature range of 30°C to 150°C and a relative humidity range of 20% to 100%. The electrolyte membrane comprises a catalytic complex in an amount of 0.01 mg / cm 2 to 0.90 mg / cm 2 of the membrane.

9. The method of claim 8, wherein, preparing the catalytic composite comprises drying a mixture comprising the catalytic particle and the oxygen permeable material at a temperature of 80°C to 200°C.

10. The method of claim 8, wherein, the catalytic particle comprises the catalytic metal component without a support, or comprises the catalytic metal component supported on a support.

11. The method of claim 10, wherein, the catalytic metal component comprises one or more selected from the group consisting of platinum, gold, palladium, silver, osmium, iridium, and ruthenium, and the support comprises one or more selected from the group consisting of carbon; silica; a zeolite; a transition metal selected from Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal.

12. The method of claim 8, wherein, the oxygen permeable material is compatible with the ionomer.

13. The method of claim 8, wherein, the ion transport layer is formed by applying the dispersion mixture on at least one surface of a reinforcing layer. the catalytic metal component comprises one or more selected from the group consisting of platinum, gold, palladium, silver, osmium, iridium, and ruthenium, and the support comprises one or more selected from the group consisting of carbon; silica; a zeolite; a transition metal selected from Groups 4B, 5B, 6B, 7B, and 8B; and an oxide or carbide of the transition metal. the oxygen permeable material is compatible with the ionomer. the ion transport layer is formed by applying the dispersion mixture on at least one surface of a reinforcing layer.

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