Electrolyte membrane for membrane-electrode assembly comprising self-assembling block copolymer

Abstract

The present invention relates to an electrolyte membrane for a membrane-electrode assembly comprising a self-assembling block copolymer comprising hydrophilic domains and hydrophobic domains.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electrolyte membrane for a membrane-electrode assembly comprising a block copolymer comprising a hydrophilic domain and a hydrophobic domain. BACKGROUND

[0002] A proton exchange membrane fuel cell (PEMFC) basically includes an anode (hydrogen gas fuel), a cathode (to which oxygen gas is supplied), and a polymer electrolyte membrane disposed between the two electrodes, and this configuration is referred to as a membrane-electrode assembly (MEA). The reaction by which a fuel cell generates electricity is to separate hydrogen gas supplied to the anode into protons and electrons, and then the protons move toward the cathode through the membrane, and the electrons move toward the cathode through an external circuit, so that oxygen molecules, protons, and electrons react on the cathode to generate electricity and heat, and produce water (H2O) as a reaction byproduct.

[0003] Here, the polymer electrolyte membrane is used to transfer the protons generated by the anode to the cathode and serves as a separator that does not allow the hydrogen gas (fuel) to come into direct contact with the oxygen gas. Generally, an electrolyte membrane composed of a perfluorosulfonic acid ionomer (PFSA) is the most commonly used electrolyte membrane in the field of polymer electrolyte membrane fuel cells because it has high performance and high stability under high proton conductivity and various wetting conditions. However, there are many problems in a pure perfluorosulfonic acid ionomer electrolyte membrane: thermal degradation easily occurs at a temperature of 100°C or higher, and the proton conductivity is also low, thereby rapidly reducing mechanical stability and dimensional stability, etc. For this reason, the operation of a fuel cell using a general perfluorosulfonic acid ionomer electrolyte membrane is generally used only in a range lower than 100°C, preferably 80°C or lower. In addition, since the proton conductivity depends on the proton exchange by the sulfonic acid donor (-SO3H group) in the presence of moisture, it is necessary to optimally maintain the hydration level of the polymer electrolyte membrane.

[0004] Generally, hydrogen gas and oxygen gas (reaction gases of a fuel cell) in the air cross through the electrolyte membrane to promote the generation of hydrogen peroxide (HOOH), in which hydrogen peroxide generates highly active oxygen-containing radicals such as a hydroxyl radical (·OH) and a hydroperoxyl radical (·OOH). The radicals cause chemical degradation of the membrane and the electrode by attacking the ionomer in the perfluorosulfonic acid-based electrolyte membrane and the electrode, thereby ultimately generating an adverse effect that reduces the durability of the fuel cell.

[0005] Generally, as a technique for retarding chemical degradation, a method of adding various types of antioxidants has been proposed. Antioxidants can use a primary antioxidant having a radical scavenger or quenching agent function and a secondary antioxidant having only a hydrogen peroxide decomposer function, respectively or interchangeably. In the general polyolefin plastic industry, primary antioxidants include phenolic antioxidants, monophenol • biphenol • polymeric phenolic antioxidants, and amine antioxidants. As secondary antioxidants (peroxide decomposers), sulfur antioxidants and phosphorus antioxidants are reported. For example, since polypropylene is more easily oxidized than polyethylene, it is known to use polypropylene in combination with secondary antioxidants (e.g., 0.1% to 1.0% of a phenolic antioxidant of 2,6-di-tert-butyl-4-methylphenol (BHT), dilauryl thiodipropionate, and octacosyl thiodipropionate).

[0006] As a representative primary antioxidant used in a perfluorosulfonic acid electrolyte membrane and an ionomer for a fuel cell, cerium groups such as cerium (III) nitrate hexahydrate or cerium oxide or cerium dioxide are known. In addition, as a secondary antioxidant, there are manganese antioxidants (e.g., manganese oxide) and transition metal catalysts (e.g., platinum (Pt)).

[0007] However, when a metal salt form is used as a primary antioxidant or a secondary antioxidant, metal ions bond to the end of a sulfonic acid group of a perfluorosulfonic acid ionomer, thereby blocking a path through which protons can move. In addition, particles of a metal or a metal oxide of several tens to several hundred nanometers in size block a hydration microchannel of an electrolyte membrane, thereby interfering with the movement of protons. Thus, generally, the use of an antioxidant in the form of a metal salt or a metal improves the chemical durability of an electrolyte membrane, but, on the contrary, can reduce the proton conductivity of the electrolyte membrane.

[0008] In the related art, an antioxidant is developed by using an organic oxidation-reduction compound having a standard oxidation-reduction potential in the range of 0.68 [V] to 1.00 [V] as an antioxidant other than a metal or a metal salt in a fuel cell. For example, TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl) oxide) having a nitroxyl radical (N-O·) is a primary-secondary composite organic antioxidant that is used as a primary antioxidant capable of converting a hydroxyl radical to a hydroxide (OH - ) (as shown in the following Reaction Formula 1) and as a secondary antioxidant (hydrogen peroxide decomposer) (as shown in the following Reaction Formula 2).

[0009] [Reaction Formula 1]

[0010]

[0011] [Reaction Formula 2]

[0012]

[0013] However, it has a disadvantage in that organic oxidation-reduction compounds having a low molecular weight are not fixed to the electrolyte membrane during operation of the fuel cell, and thus can be easily diffused and eluted through hydration channels.

[0014] The above information disclosed in this Background section is only for enhancing the understanding of the background of the present application, and therefore it can contain information that does not constitute the prior art that is already known in this country to those skilled in the art. SUMMARY

[0015] In one preferred aspect, there is provided an additive capable of maintaining the performance of an electrolyte membrane and improving the durability thereof.

[0016] In another preferred aspect, there is provided an additive capable of simultaneously improving the proton conductivity and the oxidation resistance of an electrolyte membrane.

[0017] In another preferred aspect, there is provided an additive capable of maintaining its function for a long time without being eluted from an electrolyte membrane.

[0018] Embodiments of the present application are not limited to the above-mentioned objects. The objects of the present application will be further clarified by the following description and will be appreciated by the methods described in the claims and combinations thereof.

[0019] In one aspect, there is provided an electrolyte membrane for a membrane-electrode assembly, which can include: an ionomer; and an additive dispersed in the ionomer. Specifically, the additive can include a block copolymer including a hydrophilic domain and a hydrophobic domain.

[0020] In a related aspect, there is provided an electrolyte membrane for a membrane-electrode assembly, which includes: a mixture including: (a) an ionomer; and (b) a block copolymer including a hydrophilic domain and a hydrophobic domain.

[0021] The term "ionomer" used herein means a polymeric material or resin including ionized groups as side chain groups linked (i.e., covalently bonded) to a polymer backbone. Preferably, these ionized groups can be functionalized to have ionic properties, for example, cationic properties or anionic properties. The ionomer can suitably include one or more polymers selected from the group consisting of fluorine-based polymers, perfluoro-sulfone-based polymers, benzimidazole-based polymers, polyimide-based polymers, polyetherimide-based polymers, polyphenylene sulfide-based polymers, polysulfone-based polymers, polyether sulfone-based polymers, polyether ketone-based polymers, polyether-ether ketone-based polymers, polyphenyl quinoxaline-based polymers, and polystyrene-based polymers.

[0022] The hydrophilic domains can include cationically conductive repeat units. For example, the hydrophilic domains can include one or more repeat units that include an acid group (e.g., sulfonate (-SO3 - ) or phosphate or other P-containing group).

[0023] In particular aspects, the cationically conductive repeat units can include at least one of the repeat units having Formula 1-1 to Formula 1-5 below,

[0024] [Formula 1-1]

[0025]

[0026] [Formula 1-2]

[0027]

[0028] [Formula 1-3]

[0029]

[0030] [Formula 1-4]

[0031]

[0032] [Formula 1-5]

[0033] where n ranges from 1 to 100,000.

[0034] The hydrophobic domains can include antioxidant repeat units.

[0035] For example, the hydrophobic domains can include one or more repeat units that include a nitric oxide moiety that includes an oxidized amine (amine oxide) that includes an oxidized secondary amine or an oxidized tertiary amine, such as those exemplified in Formula 2-1 to Formula 2-10 below.

[0036] The antioxidant repeat units can include at least one of the repeat units having Formula 2-1 to Formula 2-10 below,

[0037] [Formula 2-1]

[0038]

[0039] [Formula 2-2]

[0040]

[0041] [Formula 2-3]

[0042]

[0043] [Formula 2-4]

[0044]

[0045] [Formula 2-5]

[0046]

[0047] [Formula 2-6]

[0048]

[0049] [Formula 2-7]

[0050]

[0051] [Formula 2-8]

[0052]

[0053] [Formula 2-9]

[0054]

[0055] [Formula 2-10]

[0056] wherein m ranges from 1 to 100,000.

[0057] Preferably, the ratio between the number of repeating units of the hydrophilic domain (n) and the number of repeating units of the hydrophobic domain (m) is about 20:80 to 70:30.

[0058] The number average molecular weight (Mn) of the block copolymer can be about 25,000 or less.

[0059] The block copolymer can form micelles comprising a core portion and a shell portion surrounding the core portion. The core portion can comprise the hydrophobic domain, and the shell portion can comprise the hydrophilic domain.

[0060] The block copolymer can have a particle radius of about 4 nm to 6 nm.

[0061] The electrolyte membrane can comprise about 1 to 10 parts by weight of the additive, based on 100 parts by weight of the ionomer.

[0062] In one aspect, a membrane-electrode assembly can be provided, which can comprise the electrolyte membrane described herein and a pair of electrodes located on both surfaces of the electrolyte membrane.

[0063] According to various exemplary embodiments, the membrane-electrode assembly can be suitably used in fuel cells and / or water electrolysis devices.

[0064] In other embodiments, a vehicle comprising the membrane-electrode assembly and / or the fuel cell disclosed herein is provided.

[0065] According to various exemplary embodiments, the additive described herein can simultaneously improve the proton conductivity and the oxidation resistance of the electrolyte membrane.

[0066] According to various exemplary embodiments, the additive described herein (i.e., the block copolymer comprising the hydrophilic domain and the hydrophobic domain) can maintain its function for a long time without being eluted from the electrolyte membrane.

[0067] Effects of the present application are not limited to the above-mentioned effects. The effects of the present application should be understood to include all effects that can be inferred from the following description.

[0068] It should be understood that the term "automotive" or "vehicular" or other similar terms used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including various boats and ships, aircraft, and the like, and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuel derived from non-petroleum sources). As referred to herein, a hybrid vehicle is a vehicle having two or more sources of power, such as a vehicle having both gasoline power and electric power.

[0069] Other aspects of the present application are discussed below. BRIEF DESCRIPTION OF DRAWINGS

[0070] The above described and other features are described in greater detail below with respect to certain embodiments illustrated in the drawings, which are given by way of, but are not limited to, illustrating the present application, in which:

[0071] Figure 1 An exemplary block copolymer according to an exemplary embodiment of the present application is shown.

[0072] Figure 2 A state in which the block copolymer according to the present application is self-assembled in a micelle form is shown.

[0073] Figure 3 Results of the oxidation resistance evaluation according to Experimental Example 2 are shown.

[0074] It should be understood that the drawings are not drawn to scale, but rather show a somewhat simplified picture of the various preferred features illustrating the basic principles of the present application. The specific design features of the present application disclosed herein, including for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

[0075] In the drawings, like reference numerals refer to like or equivalent parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0076] As described above, the objects, other objects, features and advantages of the present application will be readily understood from the following preferred embodiments, which are described with reference to the accompanying drawings. However, the present application is not limited to the embodiments described herein and can be implemented in other forms. Rather, the embodiments introduced herein are provided so that the present application can be more thoroughly and completely conveyed to those skilled in the art and so that the spirit of the present application can be fully conveyed to those skilled in the art.

[0077] In describing each drawing, like reference numerals are used to refer to like components. In the drawings, the size of the structures will be exaggerated for clarity of the application. The terms "first", "second", and the like can be used to describe various components, but the components should not be limited to these terms. These terms are only used to distinguish one element from another. For example, a first component can be termed a second component, and similarly, a second component can also be termed a first component without departing from the scope of the application. The singular form can include the plural form unless the context clearly dictates otherwise.

[0078] In this specification, it is to be understood that terms such as "include" or "have" are intended to indicate existence of several components, numbers, steps, operations, components, parts or combinations thereof described in the specification, but not exclude the possibility of additional one or more components, numbers, steps, operations, components, parts or combinations thereof. Also, when a part (for example, a layer, a film, a region or a plate) is referred to as being "on" another part, it can be directly on the other part, or intervening parts can be present. Conversely, when a part (for example, a layer, a film, a region or a plate) is referred to as being "under" another part, it can be directly under the other part, or intervening parts can be present.

[0079] Unless otherwise indicated, all numbers, values and / or expressions regarding quantities of ingredients, reaction conditions, polymer compositions, and formulas used herein are to be understood to be modified in all instances by the term "about" as such numbers, values and / or expressions inherently contain a range of variability due to the nature of measurement of these quantities. Additionally, the term "about" is used herein to express the inherent variability in these quantities due to, for example, measurement methodology, the nature of the components being measured, and the like. Unless otherwise stated, the term "about" is understood to be within 10% of the value stated, for example, within 5% or within 1% of the stated value. Unless otherwise stated, all numerical values provided herein are modified by the term "about."

[0080] Further, if a range of values is disclosed herein, unless otherwise stated, the range is a continuous range of values and includes each and every value and / or sub-range within the range. Further, unless the context clearly indicates otherwise, the range is inclusive of the recited maximum and minimum values. Further, if such ranges involve integers, the range is intended to include each and every integer within the range, unless the context clearly dictates otherwise. For example, a range of "5 to 10" should be interpreted to include any sub-range between and including the values of 5 and 10, e.g., 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., as well as single values within the range, e.g., 5, 6, 7, 8, 9, and 10, and is further understood to include any value within the range, e.g., 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc.

[0081] It is to be understood that the term "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles such as passenger cars, including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including various boats and ships, and aircraft, 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 referred to herein, a hybrid vehicle is a vehicle having two or more sources of power, such as a vehicle having both gasoline power and electric power.

[0082] The electrolyte membrane for the membrane-electrode assembly can include an ionomer and an additive dispersed in the ionomer.

[0083] The ionomer used herein can transfer protons within the electrolyte membrane.

[0084] The ionomer can include a perfluorosulfonic acid polymer having a functional group capable of transferring protons (e.g., Nafion).

[0085] The additive can include Figure 1 The block copolymer shown. The block copolymer can include a hydrophilic domain (A) and a hydrophobic domain (B).

[0086] The hydrophilic domain (A) can include a cation conductive repeating unit.

[0087] The cation conductive repeating unit is a repeating unit including a functional group capable of transferring protons (e.g., a sulfonic acid group), and can include one or more repeating units having Formula 1-1 to Formula 1-5 below.

[0088] [Formula 1-1]

[0089]

[0090] [Formula 1-2]

[0091]

[0092] [Formula 1-3]

[0093]

[0094] [Formula 1-4]

[0095]

[0096] [Formula 1-5]

[0097] n ranges from 1 to 100,000.

[0098] The block copolymer including the hydrophilic domain (A) can provide a new proton movement path in addition to the ionomer within the electrolyte membrane, thereby significantly improving the proton conductivity of the electrolyte membrane.

[0099] The hydrophobic domain (B) can include an antioxidant repeating unit.

[0100] The antioxidant repeating unit can have a partial structure capable of converting a hydroxyl radical to a hydroxide ion or decomposing hydrogen peroxide through a reaction pathway of the following Reaction Formula 1 and Reaction Formula 2.

[0101] [Reaction Formula 1]

[0102]

[0103] [Reaction Formula 2]

[0104]

[0105] The antioxidant repeating unit can include one or more repeating units represented by the following Formulae 2-1 to 2-10.

[0106] [Formula 2-1]

[0107]

[0108] [Formula 2-2]

[0109]

[0110] [Formula 2-3]

[0111]

[0112] [Formula 2-4]

[0113]

[0114] [Formula 2-5]

[0115]

[0116] [Formula 2-6]

[0117]

[0118] [Formula 2-7]

[0119]

[0120] [Formula 2-8]

[0121]

[0122] [Formula 2-9]

[0123]

[0124] [Formula 2-10]

[0125]

[0126] The ratio (n:m) between the number of repeating units of the hydrophilic domain (n) and the number of repeating units of the hydrophobic domain (m) can be about 20:80 to 70:30. When the ratio of the number of repeating units of the hydrophobic domain (m) is greater than about 80, the particle radius of the block copolymer can become too large, such that the proton conductivity can not be improved.

[0127] Further, the number average molecular weight (Mn) of the block copolymer can be about 25,000 or less, about 10,000 or less, or about 8,000 or less. The lower limit of the number average molecular weight (Mn) is not particularly limited. When the number average molecular weight of the block copolymer is greater than about 25,000, the particle radius of the block copolymer can become large, such that the proton conductivity can not be improved.

[0128] The electrolyte membrane exists in a wet state, and the block copolymer includes all of the hydrophilic domains and the hydrophobic domains in one molecule. For example, as shown in FIG. 1, the block copolymer self-assembles within the electrolyte membrane, thereby forming a micelle form including a core portion 10 and a shell portion 20 surrounding the core portion 10. Figure 2

[0129] The particle radius of the block copolymer can be about 4 nm to 6 nm. In the present specification, the "particle radius" indicates a straight-line distance from a center point of a micelle unit to a surface of the shell portion in a state in which the block copolymer self-assembles in a micelle form. Further, the particle radius indicates a particle radius when the block copolymer is in a hydrated state. For example, according to a cluster-network model (a fine molecular structure of hydrated Nafion), sulfonate groups (-SO3 - ) adsorb water to form spherical clusters having a diameter of about 4 nm, and a proton moving path is referred to as a narrow channel having a width of 1 nm and connecting continuous clusters. Therefore, in order to increase the proton conductivity, the particle radius of the block copolymer can be about 4 nm to 6 nm, or particularly about 4 nm to 5 nm.

[0130] The electrolyte membrane can include 1 to 10 parts by weight of an additive based on 100 parts by weight of the ionomer. When the content of the additive is less than about 1 part by weight, the effect of improving the proton conductivity and the oxidation resistance can be insufficient, and when the content of the additive is greater than about 10 parts by weight, the amount thereof can be excessive, which can rather decrease the proton conductivity of the electrolyte membrane.

[0131] Examples

[0132] Exemplary embodiments of the present application will be described in greater detail by the following examples. The following exemplary embodiments are only for helping understanding of the present application, and the scope of the present application is not limited thereto.

[0133] Manufacture Example 1 to Manufacture Example 3

[0134] The block copolymer was manufactured by the following method.

[0135] As the monomer of the hydrophobic domain, 2,2,6,6-tetramethyl-4-piperidyl methacrylate represented by the following formula 3 was used as a hydrophobic monomer.

[0136] [Formula 3] ​

[0137]

[0138] As the monomer of the hydrophilic region, sodium p-styrenesulfonate represented by the following formula 4 was used as the hydrophilic monomer.

[0139] [Formula 4]

[0140]

[0141] The block copolymer was synthesized by the following reversible addition-fragmentation chain transfer (RAFT).

[0142] First, 10 g of the hydrophobic monomer (0.04 mole), 0.146 g of 2,2'-azobis(2-methylpropionitrile) (AIBN) (0.8 mole), and 1.117 g of 4-cyano-4-(phenylthiocarbamothioyl) valeric acid (0.01 mole) were added to 20 mL of anhydrous toluene, and dissolved oxygen was removed, followed by argon purging. After reaction at a temperature of about 55°C to 75°C for 5 hours, polymerization was completed after cooling. After the reactants were precipitated in a hexane solvent, the precipitate was obtained by centrifugation, and dried in a reduced pressure oven for one day, to obtain an intermediate represented by the following formula 5.

[0143] [Formula 5]

[0144]

[0145] 0.02 moles of the intermediate, the hydrophilic monomer, and 0.146 g of AIBN (0.8 mole) were added to a mixed solvent of water and methanol. At this time, samples in which the amount of the hydrophilic monomer added was adjusted to 0.01 mole (Manufacturing Example 1), 0.02 mole (Manufacturing Example 2), and 0.04 mole (Manufacturing Example 3) were respectively manufactured.

[0146] After each sample was reacted at a temperature of about 55°C to 75°C for 5 hours, polymerization was completed by cooling. After the reactants were precipitated in a hexane solvent, the precipitate was obtained by centrifugation, and dried in a reduced pressure oven for one day, to obtain a copolymer.

[0147] 5 g of the copolymer and 17.25 g of meta-chloroperoxybenzoic acid (mCPBA) (0.1 mole) were added to 50 mL of dichloromethane, and stirred at room temperature for 12 hours, to oxidize the copolymer. After the reactants were precipitated in a hexane solvent, the precipitate was obtained by centrifugation, and dried in a reduced pressure oven for one day, to obtain a block copolymer according to an exemplary embodiment of the present application represented by the following formula 6.

[0148] [Formula 6]

[0149]

[0150] The physical properties of the block copolymers of Manufacturing Example 1, Manufacturing Example 2, and Manufacturing Example 3 were measured. The results are shown in Table 1 below.

[0151] Table 1

[0152] Item m / n 1) ]] Number average molecular weight 2) ]] Particle radius [nm] Manufacture Example 1 43 / 57 6000 2.3 Manufacture Example 2 31 / 69 8000 3.4 Manufacture Example 3 73 / 27 23000 5.2

[0153] 1) The ratio (m / n) of the number of repeating units (n) of the hydrophilic domain to the number of repeating units (m) of the hydrophobic domain, by 1 H-NMR

[0154] 2) By DOSY-NMR

[0155] 3) By dynamic light scattering (DLS)

[0156] Examples 1 to 4 and Comparative Example

[0157] A Nafion solution was prepared. Based on 100 parts by weight of Nafion (ionomer) contained in the Nafion solution, a mixture was manufactured by adding 1 part by weight (Example 1), 3 parts by weight (Example 2), 5 parts by weight (Example 3), and 10 parts by weight (Example 4) of the block copolymer of Manufacturing Example 1, respectively.

[0158] An electrolyte membrane was manufactured by applying each of the mixtures to a separator paper, and then drying and heat-treating the mixture.

[0159] An electrolyte membrane manufactured only with the Nafion solution without the addition of the block copolymer was set as a comparative example.

[0160] Experimental Example 1 - Proton conductivity measurement

[0161] The proton conductivity of the electrolyte membranes according to Examples 1 to 4 and the comparative example was measured in-plane under conditions of 80°C and 50% relative humidity. The results are shown in Table 2 below.

[0162] Table 2

[0163] Item Content of block copolymer Thickness of electrolyte membrane Proton conductivity Comparative Example 0 parts by weight 28 μm 45.1 mS / cm Example 1 1 parts by weight 24 μm 46.5 mS / cm Example 2 3 parts by weight 28 μm 48.6 mS / cm Example 3 5 parts by weight 26 μm 51.4 mS / cm Example 4 10 parts by weight 31 μm 38.2 mS / cm

[0164] As shown in Table 2, Example 3 showed the highest proton conductivity, and the value was improved by about 6 mS / cm compared to the comparative example.

[0165] Experimental Example 2 - Oxidation resistance evaluation

[0166] The oxidation resistance was evaluated by measuring the change in the release of fluoride ions over time of the electrolyte membranes according to Examples 1 to 4 and the comparative example. The results are shown in Table 3 below. Figure 3 Table 3

[0167] As Figure 3 shown, Examples 1 to 4 show significantly lower release of fluoride ions compared to the comparative example, so it can be seen that when the block copolymer according to the exemplary embodiments of the present application is added as an additive, the chemical durability of the electrolyte membrane can be significantly improved.

[0168] As described above, the experimental examples and examples according to the various exemplary embodiments of the present application have been described in detail, however the scope of the present application is not limited to the above experimental examples and examples, and various forms changed and improved by the basic concept of the present application defined by the claims using by those skilled in the art are also included in the scope of the present application.

Claims

1. An electrolyte membrane for a membrane-electrode assembly, the electrolyte membrane comprising: The mixture comprises: (a) Isopolymers; and (b) A block copolymer comprising hydrophilic and hydrophobic water regions. in, The hydrophobic water contains antioxidant repeating units, and The antioxidant repeating unit contains oxygen free radicals bonded to nitrogen.

2. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The hydrophilic water contains repeating units with cationic conductivity.

3. The electrolyte membrane for a membrane-electrode assembly according to claim 2, in, The cation-conductive repeating unit comprises one or more repeating units having the following formulas 1-1 to 1-5. [Equation 1-1] [Equation 1-2] [Equation 1-3] [Equations 1-4] [Equations 1-5] Where n ranges from 1 to 100000.

4. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The antioxidant repeating unit comprises one or more repeating units having the following formulas 2-1 to 2-10. [Equation 2-1] [Equation 2-2] [Equation 2-3] [Equation 2-4] [Equation 2-5] [Equation 2-6] [Equation 2-7] [Equation 2-8] [Equation 2-9] [Equation 2-10] Where m ranges from 1 to 100000.

5. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The ratio between the number of repeating units n in the hydrophilic water area and the number of repeating units m in the hydrophobic water area is 20:80 to 70:

30.

6. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The number-average molecular weight Mn of the block copolymer is 25,000 or less.

7. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The block copolymer is formed into micelles, each micelle comprising a core portion and a shell portion surrounding the core portion, and The core portion contains hydrophobic water, and the outer shell portion contains hydrophilic water.

8. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, The particle radius of the block copolymer is 4 nm to 6 nm.

9. The electrolyte membrane for a membrane-electrode assembly according to claim 1, in, It contains 1 to 10 parts by weight of additives per 100 parts by weight of ionomer.

10. A membrane-electrode assembly comprising: The electrolyte membrane according to claim 1; and A pair of electrodes located on the two surfaces of the electrolyte membrane.

11. A fuel cell comprising the membrane-electrode assembly of claim 10.

12. A water electrolysis apparatus comprising the membrane-electrode assembly of claim 10.

13. A vehicle comprising the membrane-electrode assembly of claim 10.

14. A vehicle comprising the fuel cell of claim 11.

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