Polymer electrolyte membrane, manufacturing method therefor, membrane-electrode assembly, and fuel cell

Abstract

Disclosed is a polymer electrolyte membrane for enhancing the performance of a membrane-electrode assembly. According to an aspect of the present invention, a polymer electrolyte membrane is provided where one or more holes are formed in at least one surface, at least one of the one or more holes including functional nanoparticles therein, wherein the arithmetic average roughness (Ra) of at least one surface of the polymer electrolyte membrane is 0.11 μm to 0.35 μm.

Description

Polymer electrolyte membrane and its manufacturing method, membrane-electrode assembly and fuel cell

[0001] The present disclosure relates to a polymer electrolyte membrane and a method for manufacturing the same, and more specifically, to a polymer electrolyte membrane and a method for manufacturing the same, a membrane-electrode assembly, and a fuel cell.

[0002] Fuel cells directly convert the chemical energy generated by fuel oxidation into electrical energy. Their high energy efficiency, low pollutant emissions, and environmental friendliness have made them a promising next-generation energy source. These fuel cells typically consist of a polymer electrolyte membrane, with an anode and cathode electrode formed on either side. This structure is called a membrane electrode assembly (MEA).

[0003] Fuel cells can be categorized into alkaline electrolyte fuel cells and polymer electrolyte membrane fuel cells (PEMFC) depending on the type of electrolyte membrane. Among them, polymer electrolyte membrane fuel cells are attracting attention as portable, automotive, and home power sources due to their advantages such as low operating temperatures below 100℃, fast start-up and response characteristics, and excellent durability. A representative example of such polymer electrolyte membrane fuel cells is the hydrogen ion exchange membrane fuel cell, which uses hydrogen gas as fuel. To summarize the reactions that occur in a polymer electrolyte membrane fuel cell, first, when a fuel such as hydrogen gas is supplied to the anode electrode (anode), hydrogen ions and electrons are generated through an oxidation reaction of the hydrogen gas at the anode. The generated hydrogen ions are transferred to the cathode electrode (reduction electrode) through the polymer electrolyte membrane, and the generated electrons are transferred to the cathode electrode (reduction electrode) through an external circuit. At the reduction electrode, oxygen gas is supplied, and the oxygen gas combines with hydrogen ions and electrons to produce water through a reduction reaction.

[0004] Meanwhile, research is continuously being conducted to improve the performance of fuel cells by reducing Ohmic polarization by improving the interfacial bonding between polymer electrolyte membranes and catalyst layers made of different materials.

[0005] According to one aspect of the present invention, a polymer electrolyte membrane having improved interfacial bonding of a catalyst layer is provided.

[0006] According to another aspect of the present invention, a polymer electrolyte membrane is provided that improves the performance of a membrane-electrode assembly.

[0007] According to another aspect of the present invention, there is provided a polymer electrolyte membrane capable of improving chemical durability, reverse voltage durability, heat dissipation effect, efficiency of catalytic reaction, or moisture retention ability.

[0008] According to another aspect of the present invention, a method for manufacturing the polymer electrolyte membrane is provided.

[0009] According to another aspect of the present invention, a membrane-electrode assembly including the polymer electrolyte membrane is provided.

[0010] According to another aspect of the present invention, a fuel cell including the membrane-electrode assembly is provided.

[0011] The purposes of the present invention are not limited to those mentioned above, and other unmentioned purposes and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0012] According to a first aspect of the present invention, there is provided a polymer electrolyte membrane having at least one hole formed on at least one surface, wherein at least one of the one or more holes includes a functional nanoparticle therein, and the centerline average roughness (Arithmetic average roughness, R) of at least one surface of the polymer electrolyte membrane a ) is provided as a polymer electrolyte membrane having a thickness of about 0.11㎛ or more and about 0.35㎛ or less.

[0013] According to a second aspect of the present invention, in the first aspect, each hole may have a depth of about 0.5 µm or more and about 5 µm or less and a width of about 0.2 µm or more and about 10 µm or less.

[0014] According to a third aspect of the present invention, in the first or second aspect, the functional nanoparticle may include at least one member selected from the group consisting of radical scavengers, catalytic nanoparticles, heat-radiating nanoparticles, and hygroscopic nanoparticles.

[0015] According to the fourth aspect of the present invention, in any one of the first to third aspects, the average size (D) of the functional nanoparticles 50 ) may be about 5 nm or more and about 170 nm or less.

[0016] According to a fifth aspect of the present invention, a method for producing a polymer electrolyte membrane is provided, comprising the steps of (S1) preparing a substrate; and (S2) coating and drying a composition for forming a surface roughness on at least one surface of the substrate to produce a polymer electrolyte membrane, wherein the composition for forming a surface roughness includes functional nanoparticles and a solvent, and the solvent includes an alcohol in an amount of more than about 10 wt% and less than about 90 wt% based on the total weight of the composition for forming a surface roughness. Here, the polymer electrolyte membrane may be characterized by any one of the first to fourth aspects or several embodiments of the present specification.

[0017] According to a sixth aspect of the present invention, in the fifth aspect, the content of the functional nanoparticles may be about 1 wt% or more and about 10 wt% or less based on the total weight of the composition for forming surface roughness.

[0018] According to the seventh aspect of the present invention, in the fifth or sixth aspect, the solvent may further include a polar solvent different from alcohol.

[0019] According to the eighth aspect of the present invention, in the seventh aspect, the polar solvent may include at least one selected from the group consisting of water, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), acetic acid, and propionic acid.

[0020] According to the ninth aspect of the present invention, in any one of the fifth to eighth aspects, the thickness of the coated surface roughness forming composition may be about 10 µm or more and about 150 µm or less.

[0021] According to a tenth aspect of the present invention, a membrane-electrode assembly is provided, comprising a polymer electrolyte membrane according to any one of the first to fourth aspects and a catalyst layer disposed on at least one surface of the polymer electrolyte membrane.

[0022] According to an eleventh aspect of the present invention, a fuel cell is provided comprising a membrane-electrode assembly according to the tenth aspect.

[0023] The solutions to the above problems are not exhaustive and may be combined with several embodiments of the present disclosure. The various features of the present invention and their corresponding advantages and effects can be understood in more detail by referring to the detailed description below.

[0024] According to one aspect of the present invention, the interfacial bonding between a polymer electrolyte membrane and a catalyst layer can be improved to significantly reduce ohmic polarization, thereby improving the performance of a membrane-electrode assembly.

[0025] According to another aspect of the present invention, chemical durability, heat dissipation effect, efficiency of catalytic reaction or moisture retention ability can be improved.

[0026] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0027] Figure 1a is a schematic diagram of a method for manufacturing a membrane-electrode assembly according to one embodiment of the present invention.

[0028] Figure 1b is a side view of Figure 1a.

[0029] Figure 2 is a schematic diagram illustrating a fuel cell according to one embodiment of the present invention.

[0030] Figure 3 is an optical microscope photograph of a polymer electrolyte membrane according to one embodiment of the present invention.

[0031] FIG. 4 is a scanning electron microscope (SEM) cross-sectional photograph of a membrane-electrode assembly according to one embodiment of the present invention.

[0032] Figure 5 is a graph showing the performance of membrane-electrode assemblies according to Comparative Examples 1 to 4 and Examples 1-1, 2 to 4.

[0033] Figure 6 is a time-voltage loss graph of the membrane-electrode assembly according to Example 1-1 and Comparative Examples 2 and 3.

[0034] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0035] The terms "comprise" and / or "comprising" in this specification specify the presence of stated features, steps, numbers, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, numbers, operations, elements, elements and / or groups thereof.

[0036] In this specification, “At least one of a, b and c” may include a, b or c alone, or a combination of two or more selected from the group consisting of a, b and c.

[0037] The term "connection" as used herein refers not only to the direct connection of certain elements, but also includes an indirect connection where another element is interposed between the elements.

[0038] If multiple embodiments are described in this specification, the embodiments may be combined unless specifically stated otherwise. In this case, the effects of the present invention may be defined as including the effects derived from each embodiment and the effects resulting from the organic combination of the embodiments. For example, even if Embodiments 1 and 2 are described independently in this specification, Embodiments 1 and 2 may be organically combined with each other, unless the context clearly indicates otherwise, and the effects of the present invention may include the effects resulting from the combination of Embodiments 1 and 2.

[0039] The numerical range indicated by the term "to" in this specification refers to a numerical range that includes the values ​​stated before and after the term as the lower and upper limits, respectively. For example, if "a" and "b" are stated in the specification, it can be understood that "a" and "b" are stated.

[0040] In the present specification, when multiple numerical values ​​are disclosed as the upper and lower limits of any numerical range, the numerical range disclosed in the present specification can be understood as any numerical range that has any one of the multiple lower limit values ​​and any one of the multiple upper limit values ​​as the lower limit value and the upper limit value, respectively. For example, when a or more, or b or more; and c or less or d or less are described, it can be understood that a or more and c or less, a or more and d or less, b or more and c or less, or b or more and d or less are described.

[0041] As used herein, terms such as "about" or "substantially" mean a reasonable amount of variation from the term that does not significantly alter the final result. These terms may be interpreted to include a variation of at least ±5% or at least ±10%, provided that such variation does not alter the meaning of the term and render it invalid.

[0042] In this specification, the term "layer" or film may include cases where it is formed not only over the entire area when observing the area where the layer or film exists, but also cases where it is formed over only a portion of the area. For example, the surface of the layer or film may be defined to include a flat shape, a non-flat shape, and a combination thereof; or a continuous shape, a discontinuous shape, and a combination thereof. For example, when another element is formed as a layer or film directly on top of one element, the coverage of the other element on the surface of the one element may be defined as 1% or more, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 99% or more. For example, even when a plurality of particles form a clustered structure, it may be defined as a "layer" or "film."

[0043] According to one aspect of the present invention, a polymer electrolyte membrane having at least one hole formed on at least one surface, wherein at least one of the one or more holes includes a functional nanoparticle therein, and the centerline average roughness (Arithmetic average roughness, R) of at least one surface of the polymer electrolyte membrane a ) is 0.11㎛ or more and 0.35㎛ or less, a polymer electrolyte membrane is provided. According to one aspect of the present invention, the centerline average roughness (Arithmetic average roughness, R) of the surface on which one or more holes are formed a) can significantly reduce Ohmic polarization by improving the interfacial bonding between the polymer electrolyte membrane and the catalyst layer, thereby improving the performance of the membrane-electrode assembly. According to another aspect of the present invention, a polymer electrolyte membrane can be provided in which functional nanoparticles are included inside the holes, thereby improving the durability, heat dissipation effect, efficiency of catalytic reaction, or water retention capacity of a fuel cell. From another perspective, the centerline average roughness of a surface on which one or more holes are formed can be a factor that controls the performance of the membrane-electrode assembly by affecting each functionality that the functional nanoparticles are intended to implement. Accordingly, when the centerline average roughness of a surface on which one or more holes are formed is outside the above numerical range, each functionality of the functional nanoparticles may be degraded, thereby degrading the performance of the membrane-electrode assembly.

[0044] Below, the configuration of the present invention is described in more detail.

[0045] 1. Polymer electrolyte membrane

[0046] The polymer electrolyte membrane according to the present invention has at least one hole formed on at least one surface. Here, at least one surface of the polymer electrolyte membrane may be the entire surface or a portion of the surface of the polymer electrolyte membrane, and specifically, may be a portion of the surface of the polymer electrolyte membrane.

[0047] In some embodiments of the present invention, at least one surface of the polymer electrolyte membrane where the hole is formed may be 20 to 70% of the total area of ​​one surface of the polymer electrolyte membrane. According to some embodiments of the present invention, since the area where the hole is formed satisfies the numerical range, durability of the polymer electrolyte membrane and interfacial adhesion between the catalyst layer and the polymer electrolyte membrane can be achieved simultaneously.

[0048] In some embodiments of the present invention, the holes may be distributed over the effective electrochemically active area of ​​the polymer electrolyte membrane. According to some embodiments of the present invention, by distributing the holes over the effective area, the interfacial adhesion between the polymer electrolyte membrane and the catalyst layer may be increased, thereby improving the durability of the membrane-electrode assembly.

[0049] The hole according to the present invention comprises the functional nanoparticles within it. The functional nanoparticles are contained within the hole, and can implement their own unique functions.

[0050] In some examples, the functional nanoparticles may include at least one selected from the group consisting of radical scavengers, catalytic nanoparticles, heat-dissipating nanoparticles, and hygroscopic nanoparticles.

[0051] In some examples, the radical scavenger can capture oxygen radicals generated during fuel cell operation. The radical scavenger can be, for example, any one selected from the group consisting of a transition metal, an ion of a transition metal, an oxide of a transition metal, a complex of a transition metal, a noble metal, an ion of a noble metal, an oxide of a noble metal, a complex of a noble metal, and combinations thereof. The transition metal can be any one selected from the group consisting of cerium (Ce), manganese (Mn), tungsten (W), cobalt (Co), vanadium (V), nickel (Ni), chromium (Cr), zirconium (Zr), yttrium (Y), iridium (Ir), iron (Fe), titanium (Ti), molybdenum (Mo), lanthanum (La), and neodymium (Nd). The above precious metal may be any one selected from the group consisting of silver (Ag), platinum (Pt), ruthenium (Ru), palladium (Pd), and rhodium (Rh). For example, the oxide of the above transition metal may be CeO2.

[0052] In some examples, the catalytic nanoparticles may be any one selected from the group consisting of platinum-based nanoparticles, OER catalytic nanoparticles, and combinations thereof.

[0053] In some examples, the platinum-based nanoparticles may be nanoparticles that improve chemical durability, for example, one or more selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), and platinum-M (Pt-M). Specifically, the M may correspond to at least one selected from the group consisting of 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), and rhodium (Rh), and more specifically, the platinum alloy may correspond to at least one selected from the group consisting of Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ru-W, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Co, Pt-Co-Ni, Pt-Co-Fe, One or more selected from the group consisting of 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-Ir and combinations thereof may be used in combination.

[0054] In some examples, the OER (oxygen evolution reaction) catalyst nanoparticles are nanoparticles that prevent the cell voltage from decreasing due to lack of air during fuel cell operation. The OER catalyst nanoparticles may be, for example, any one selected from the group consisting of ruthenium oxide (RuO2), iridium oxide (IrO2), and combinations thereof.

[0055] In some examples, the heat-dissipating nanoparticles are nanoparticles that transfer heat generated during fuel cell operation to the outside of the catalyst layer, and may be, for example, one or more selected from the group consisting of metal nanoparticles, ceramic nanoparticles, and carbon nanoparticles.

[0056] In some examples, the metal nanoparticles may be selected from the group consisting of Al, Mg, Cu, Ni, Ag, and core-shell nanoparticles having excellent thermal conductivity. In the core-shell nanoparticles, a metal or metalloid belonging to groups 2 to 15 of the periodic table may be used as the core, and a metal having excellent thermal conductivity or being relatively stable may be used as the shell. The core-shell nanoparticles may be, for example, Cu@Ag, Fe@Al, or Cu@Au.

[0057] In some examples, the ceramic nanoparticles may be one or more selected from the group consisting of boron nitride, aluminum nitride, aluminum oxide, silicon carbide, and beryllium oxide. The ceramic nanoparticles have excellent thermal conductivity, so they can easily transfer heat to the outside of the catalyst layer and have the effect of preventing moisture within the catalyst layer from evaporating.

[0058] According to one embodiment of the present invention, the boron nitride may be hexagonal boron nitride (h-BN). The hexagonal boron nitride has properties and a plate-like structure similar to graphite, and thus can have excellent thermal conductivity, insulation, and chemical stability at high temperatures.

[0059] The above carbon nanoparticles may be, for example, at least one selected from the group consisting of carbon nanofibers, carbon black, acetylene black, carbon nanotubes (CNTs), carbon spheres, carbon ribbons, fullerenes, graphene, and activated carbon.

[0060] The above hygroscopic nanoparticles may be nanoparticles that effectively absorb moisture generated during fuel cell operation. Specifically, the hygroscopic nanoparticles may be, for example, hydrophilic silica nanoparticles, titanium dioxide (TiO2), etc.

[0061] In this specification, the average particle size is the particle diameter (D) when the cumulative percentage in the volume-based particle size distribution curve is 50% when measured by a laser diffraction particle size distribution measuring device. 50 ) can be defined. For example, the average size of the particles can be calculated by dispersing the target particles in a dispersion medium, introducing them into a commercially available laser diffraction particle size measuring device (e.g., Microtrac S3500), and measuring the difference in diffraction pattern according to particle size when the particles pass through a laser beam.

[0062] The average size of the functional nanoparticles according to the present invention may be 5 nm or more and 170 nm or less, or 5 nm or more and 150 nm or less. When the average size of the functional nanoparticles satisfies the above numerical range, they can be effectively dispersed in the composition for forming surface roughness. For example, when the functional nanoparticles are radical scavengers, the average size of the radical scavenger may be 5 nm or more, 7 nm or more, 9 nm or more, or 10 nm or more; and 15 nm or less, 20 nm or less, 25 nm or less, 30 nm or less, 40 nm or less, 45 nm or less, or 50 nm or less. As another example, when the functional nanoparticles are heat-radiating nanoparticles, the average size of the heat-radiating nanoparticles may be 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 145 nm or more, or 150 nm or more; And it can be 155 nm or less, 160 nm or less, 170 nm or less, 180 nm or less, 190 nm or less, or 200 nm or less. By controlling the average size of the radical scavenger and the heat-radiating nanoparticles within the above numerical range, they can be effectively dispersed in the composition for forming surface roughness.

[0063] In some examples, the shape of the hole is not particularly limited, but may be polygonal or semicircular in cross section, and specifically, may be triangular, square, pentagonal, etc.

[0064] In some examples, the holes may be irregularly or randomly formed on the surface of the polymer electrolyte membrane. In some embodiments of the present invention, each hole may have a depth of 0.5 μm or more and 5 μm or less, and a width of 0.2 μm or more and 10 μm or less, specifically, a depth of 0.5 to 4 μm and a width of 0.5 to 8 μm, and more specifically, a depth of 0.8 to 3 μm, 1 to 2.5 μm, or 1.5 to 2.0 μm and a width of 1 to 7 μm, 2 to 6 μm, 3 to 5 μm, or 3 to 4 μm. Here, the depth and width of the hole may refer to the depth and width of an individual hole when a plurality of holes are formed. When the depth and width of the hole satisfy the numerical range, the durability of the polymer electrolyte membrane can be sufficiently secured, and deformation of the polymer electrolyte membrane can be minimized. In addition, the depth and width of the hole are factors that affect the interfacial adhesion between the polymer electrolyte membrane and the catalyst layer, and by satisfying the above numerical range, the performance of the membrane-electrode assembly can be further improved.

[0065] Arithmetical average roughness (R) of the center line of at least one side of the polymer electrolyte membrane according to the present invention a) is 0.11 ㎛ or more and 0.35 ㎛ or less. Specifically, the centerline average roughness of at least one side of the polymer electrolyte membrane is 0.110 ㎛ or more, 0.111 ㎛ or more, 0.120 ㎛ or more, 0.125 ㎛ or more, 0.130 ㎛ or more, 0.140 ㎛ or more, 0.150 ㎛ or more, 0.155 ㎛ or more, 0.160 ㎛ or more, 0.170 ㎛ or more, 0.180 ㎛ or more, 0.185 ㎛ or more, 0.190 ㎛ or more, or 0.192 ㎛ or more; And it may be 0.197㎛ or less, 0.205㎛ or less, 0.214㎛ or less, 0.220㎛ or less, 0.230㎛ or less, 0.250㎛ or less, 0.280㎛ or less, 0.300㎛ or less, 0.338㎛ or less, 0.340㎛ or less, or 0.350㎛ or less. More specifically, the centerline average roughness of at least one surface of the polymer electrolyte membrane may be 0.110 to 0.300㎛, 0.120 to 0.280㎛, 0.130 to 0.250㎛, 0.140 to 0.230㎛, 0.150 to 0.220㎛, or 0.190 to 0.220㎛. Here, at least one surface of the polymer electrolyte membrane may be a surface of the polymer electrolyte membrane in which one or more holes are formed. In order to analyze the above-mentioned centerline average roughness, a surface roughness measuring device commercially available in the relevant technical field can be used. Specifically, by controlling the centerline average roughness of the surface of the polymer electrolyte membrane, the interfacial adhesion between the polymer electrolyte membrane and the catalyst layer, and the performance and mechanical durability of the membrane-electrode assembly can be changed. According to some embodiments of the present invention, the centerline average roughness (Arithmetic average roughness, R) of at least one surface of the polymer electrolyte membrane a) is below the above numerical range, a problem may arise in which functional nanoparticles are not sufficiently loaded into the holes, and if it exceeds the above numerical range, the interfacial adhesion between the polymer electrolyte membrane and the catalyst layer may be reduced, and the resistance may be excessively increased, resulting in a problem in which the performance of the membrane-electrode assembly may be reduced. In addition, the centerline average roughness of at least one side of the polymer electrolyte membrane is a factor that affects the functionality of the functional nanoparticles, and if it exceeds the above numerical range, the functionality of the functional nanoparticles may be reduced, thereby lowering the performance of the membrane-electrode assembly.

[0066] According to one embodiment of the present invention, the polymer electrolyte membrane may be, for example, a conventional single membrane in the relevant technical field.

[0067] According to another embodiment of the present invention, the polymer electrolyte membrane may be a reinforced composite membrane in which an ion conductor is impregnated into a porous support.

[0068] The porous support may be, for example, expanded polytetrafluoroethylene (e-PTFE) having a microstructure of polymer fibrils or a microstructure in which nodes are interconnected by fibrils. Additionally, a film having a microstructure of polymer fibrils without nodes may also be used as the porous support.

[0069] The above ion conductor may be, for example, any one selected from the group consisting of fluorine-based ionomers, hydrocarbon-based ionomers, and mixtures thereof.

[0070] The above fluorine-based ionomer may be, for example, any one selected from the group consisting of a fluorine-based polymer containing fluorine in the main chain, poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), a copolymer of tetrafluoroethylene and fluorovinyl ether containing a sulfonic acid group, a polystyrene-graft-ethylenetetrafluoroethylene copolymer, a polystyrene-graft-polytetrafluoroethylene copolymer, and mixtures thereof.

[0071] The hydrocarbon ionomers include, for example, sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (S-PEEK), sulfonated polybenzimidazole (S-PBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S-PS), sulfonated polyphosphazene, sulfonated polyquinoxaline, sulfonated polyketone, sulfonated polyphenylene oxide, sulfonated polyether sulfone, Sulfonated polyether ketone, sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene sulfide sulfone, sulfonated polyphenylene sulfide sulfone nitrile, sulfonated polyarylene ether, sulfonated polyarylene ether nitrile, sulfonated polyarylene ether ether nitrile,It may be any one selected from the group consisting of sulfonated polyarylene ether sulfone ketone and mixtures thereof.

[0072] 2. Method for manufacturing polymer electrolyte membrane

[0073] According to another aspect of the present invention, a method for manufacturing a polymer electrolyte membrane is provided, comprising the steps of (S1) preparing a substrate; and (S2) coating and drying a composition for forming a surface roughness on at least one surface of the substrate to manufacture a polymer electrolyte membrane, wherein the composition for forming a surface roughness includes functional nanoparticles and a solvent, and the solvent includes an alcohol in an amount of more than 10 wt% and less than 90 wt% based on the total weight of the composition for forming a surface roughness.

[0074] In some examples, the substrate may be a commercially available electrolyte membrane used in the relevant technical field. The thickness of the substrate is not particularly limited and may vary. Specifically, the substrate may include the ion conductor described above, and more specifically, any one selected from the group consisting of fluorine-based ionomers, hydrocarbon-based ionomers, and mixtures thereof.

[0075] The content of the functional nanoparticles according to the present invention may be 1 to 10 wt%, specifically 1.5 to 9 wt%, and more specifically 2 to 8 wt%, 3 to 7 wt%, 4 to 6 wt%, or 5 to 6 wt%, based on the total weight of the composition for forming surface roughness. When the content of the functional nanoparticles satisfies the above numerical range, dispersibility can be sufficiently secured in the composition for forming surface roughness, and the function of each functional nanoparticle can be sufficiently implemented when applied to a polymer electrolyte membrane.

[0076] The composition for forming surface roughness according to the present invention comprises a solvent. Specifically, the solvent is a volatile solvent that can be applied to the surface of a polymer electrolyte membrane and then dried and evaporated under heat treatment conditions.

[0077] The solvent according to the present invention may contain alcohol in an amount of more than 10 wt% and less than 90 wt% based on the total weight of the composition for forming surface roughness. Specifically, the content of the alcohol is 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, or 70 wt% or more; 20 wt% or less, 25 wt% or less, 30 wt% or less, 35 wt% or less, 40 wt% or less, 45 wt% or less, 50 wt% or less, 55 wt% or less, 60 wt% or less, 65 wt% or less, 70 wt% or less, 75 wt% or less, 80 wt% or less, or 85 wt% or less based on the total weight of the composition for forming surface roughness. Or any one of the plurality of lower limits may be greater than or equal to any one of the plurality of upper limits. For example, based on the total weight of the composition for forming surface roughness, the content of the alcohol may be 20 wt% or more and less than 90 wt%, 30 wt% or more and less than 90 wt%, 40 wt% or more and less than 90 wt%, 50 wt% or more and less than 90 wt%, or 70 wt% or more and less than 90 wt%, or 50 wt% or more and less than 90 wt%, 55 to 85 wt%, 60 to 80 wt%, 65 to 75 wt%, or 70 to 75 wt%. When the content of the alcohol satisfies the numerical range based on the total weight of the composition for forming surface roughness, holes can be sufficiently randomly generated on the surface of the polymer electrolyte membrane through the drying process of the composition for forming surface roughness. If the content of the alcohol is outside the above numerical range, a problem may arise in which holes are not sufficiently generated, making it difficult to support functional nanoparticles, or an excessive number of holes may be generated on the surface of the polymer electrolyte membrane, increasing resistance and deteriorating the performance of the membrane-electrode assembly.

[0078] In some examples, the boiling point of the alcohol may be 140° C. or less, specifically 135° C. or less, and more specifically 60 to 135° C. When the boiling point of the alcohol satisfies the above numerical range, when the composition for forming surface roughness is applied to the surface of the polymer electrolyte membrane, the solvent included in the applied composition can be easily evaporated by high temperature heat. The alcohol may include, for example, at least one selected from the group consisting of methanol, ethanol, propanol, and 2-ethoxyethanol.

[0079] In this specification, “polar solvent” may be defined as a solvent having a dielectric constant of 15 or more.

[0080] In some embodiments of the present invention, the solvent may further comprise a polar solvent different from the alcohol. Specifically, the polar solvent may contribute to the dispersion of the functional nanoparticles and the formation of a roughness on the surface of the polymer electrolyte membrane.

[0081] The polar solvent may include, for example, at least one selected from the group consisting of water, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), acetic acid, and propionic acid.

[0082] In some embodiments of the present invention, the content of the polar solvent different from the alcohol may be greater than 0 and less than or equal to 60 wt%, specifically 5 to 50 wt%, more specifically 10 to 40 wt%, 15 to 35 wt%, 20 to 30 wt%, or 25 to 30 wt%, based on the total weight of the composition for forming the surface roughness. According to some embodiments of the present invention, by satisfying the numerical range of the content of the polar solvent different from the alcohol, the surface roughness of the polymer electrolyte membrane can be formed at an appropriate level, while at the same time further improving the dispersibility of the functional nanoparticles.

[0083] The composition for forming surface roughness according to the present invention can be coated on at least one surface of the polymer electrolyte membrane. As a method for coating the composition for forming surface roughness, for example, a slot-die coating method, a comma coating method, or a spray coating method can be used.

[0084] The wet film thickness (WFT) of the surface roughness-forming composition for the polymer electrolyte membrane according to the present invention may be 10 μm or more and 150 μm or less, specifically 15 μm or more and 130 μm or less, and more specifically 20 μm or more and 110 μm or less. The wet film thickness (WFT) of the surface roughness-forming composition for the polymer electrolyte membrane is the thickness of the surface roughness-forming composition before it is dried, and may refer to the thickness of the coated surface roughness-forming composition. When the thickness of the coated surface roughness-forming composition satisfies the above numerical range, process implementation may be easy, drying may occur sufficiently without affecting the subsequent process, and a hole having an optimal depth may be formed on the surface of the polymer electrolyte membrane to prevent durability from being deteriorated. For the polymer electrolyte membrane, the wet film thickness of the composition for forming the surface roughness may be, for example, a gap defined between the coating equipment and the surface of the substrate during coating.

[0085] The composition for forming the surface roughness coated on at least one surface of the polymer electrolyte membrane can be dried at 60 to 150°C for 10 to 300 seconds, and specifically, can be dried at 60 to 135°C for 100 to 300 seconds. If the drying temperature is less than the above numerical range, the solvent may not be completely dried, which may affect the post-process or form deep holes on the surface of the polymer electrolyte membrane, thereby reducing durability. If the drying temperature is greater than the above numerical range, the polymer electrolyte membrane may be deformed.

[0086] 3. Membrane-electrode assembly

[0087] According to another aspect of the present invention, a membrane-electrode assembly is provided, comprising: the polymer electrolyte membrane; and a catalyst layer disposed on at least one surface of the polymer electrolyte membrane. According to one aspect of the present invention, since the surface roughness is irregularly formed on the surface of the polymer electrolyte membrane, the contact area between the polymer electrolyte membrane and the catalyst layer can be relatively widened, and thus the interfacial adhesion between the polymer electrolyte membrane and the catalyst layer can be significantly improved.

[0088] Hereinafter, the configuration of the present invention will be described in detail with reference to FIGS. 1a, 1b and 2.

[0089] Fig. 1a is a schematic diagram of a method for manufacturing a membrane-electrode assembly according to one embodiment of the present invention. Fig. 1b is a side view of Fig. 1a.

[0090] Referring to FIGS. 1a and 1b, a method for manufacturing a membrane-electrode assembly (50) according to the present invention may include: (a) a step of coating the composition for forming a surface roughness on at least one surface of a polymer electrolyte membrane (10); (b) a step of drying the polymer electrolyte membrane (10) coated with the composition for forming a surface roughness; and (c) a step of forming a catalyst layer (20) on at least one surface of the dried polymer electrolyte membrane.

[0091] In the above step (a), the composition for forming surface roughness can form a hole on at least one surface of the polymer electrolyte membrane.

[0092] Through the drying step of step (b) above, the solvent included in the composition for forming surface roughness is evaporated, so that the functional nanoparticles (15) can be placed inside the holes. The functional nanoparticles (15) can each implement the functions described above.

[0093] Specifically, the above step (c) can be performed by a batch type, roll-to-roll type decal transfer method, or a direct coating method in which the electrode slurry is directly coated on the surface of the polymer electrolyte membrane.

[0094] As a catalyst of the catalyst layer (20) according to the present invention, any catalyst that participates in the reaction of the cell and can be used as a catalyst for a typical fuel cell can be used, and preferably, a platinum-based metal can be used. The platinum-based metal may include one selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), a platinum-M alloy, a non-platinum alloy, and combinations thereof, and more preferably, a combination of two or more metals selected from the platinum-based catalyst metal group can be used, but is not limited thereto, and any platinum-based catalyst metal usable in the present technical field can be used without limitation. The above M may correspond to at least one selected from the group consisting of 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), and rhodium (Rh). Specifically, the platinum alloy may be used alone or in combination of two or more selected from the group consisting of Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ru-W, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Co, 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-Ir and combinations thereof.In addition, the non-platinum alloy may be used alone or in combination of two or more selected from the group consisting of Ir-Fe, Ir-Ru, Ir-Os, Co-Fe, Co-Ru, Co-Os, Rh-Fe, Rh-Ru, Rh-Os, Ir-Ru-Fe, Ir-Ru-Os, Rh-Ru-Fe, Rh-Ru-Os, and combinations thereof.

[0095] The catalyst itself (black) may be used as the catalyst, or it may be supported on a carrier. The carrier may be, for example, one selected from the group consisting of a carbon-based carrier, a porous inorganic oxide, a zeolite, and a combination thereof. The carbon-based carrier may be, for example, selected from 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, carbon aerogel, graphene, stabilized carbon, activated carbon, and a combination of at least one or more thereof, but is not limited thereto. The above porous inorganic oxide may correspond to at least one selected from the group consisting of, for example, zirconia, alumina, titania, silica, and ceria. The surface area of ​​the carrier may be 50 m 2 / g or more may be preferable, and the average particle diameter may be 10 to 300 nm. If the surface area of ​​the carrier is less than the above numerical range, a uniform distribution of metal nanoparticles may not be obtained.

[0096] 4. Fuel cell

[0097] According to another aspect of the present invention, a fuel cell including the membrane-electrode assembly is provided.

[0098] Figure 2 is a schematic diagram illustrating a fuel cell according to one embodiment of the present invention.

[0099] Referring to FIG. 2, a fuel cell (200) according to the present invention may include a fuel supply unit (210) that supplies a mixed fuel in which fuel and water are mixed, a reforming unit (220) that reforms the mixed fuel to generate a reformed gas containing hydrogen gas, a stack (230) that generates electrical energy by causing an electrochemical reaction between the reformed gas containing hydrogen gas supplied from the reforming unit (220) and an oxidizer, and an oxidizer supply unit (240) that supplies an oxidizer to the reforming unit (220) and the stack (230).

[0100] The above stack (230) may be equipped with a plurality of unit cells that generate electrical energy by inducing an oxidation / reduction reaction of a reforming gas containing hydrogen gas supplied from the reforming unit (220) and an oxidizing agent supplied from the oxidizing agent supply unit (240).

[0101] Each unit cell refers to a unit cell that generates electricity, and may include the membrane-electrode assembly that oxidizes / reduces oxygen in a reforming gas containing hydrogen gas and an oxidizing agent, and a separator (also called a bipolar plate, hereinafter referred to as a "separator") for supplying the reforming gas containing hydrogen gas and the oxidizing agent to the membrane-electrode assembly. The separator is positioned on both sides of the membrane-electrode assembly with the membrane-electrode assembly at the center. At this time, the separator plates each positioned at the outermost side of the stack are specifically referred to as end plates.

[0102] Among the above separators, the end plate may be provided with a first supply pipe (231) in the shape of a pipe for injecting reformed gas containing hydrogen gas supplied from the reforming unit (220), and a second supply pipe (232) in the shape of a pipe for injecting oxygen gas, and the other end plate may be provided with a first discharge pipe (233) for discharging reformed gas containing hydrogen gas that is ultimately unreacted and remains in a plurality of unit cells to the outside, and a second discharge pipe (234) for discharging oxidant that is ultimately unreacted and remains in the unit cells to the outside.

[0103] In the above fuel cell, the separator, fuel supply unit, and oxidizer supply unit constituting the electricity generation unit are used in a typical fuel cell, and therefore, a detailed description thereof is omitted in this specification.

[0104] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, this is merely an example, and the scope of the present invention is not limited by the following contents.

[0105] [Manufacturing Example 1: Preparation of a composition for forming surface roughness]

[0106] <Comparative Preparation Example 1: Composition having an alcohol content of 10 wt% or less>

[0107] Average size (D 50 ) was prepared to form a surface roughness composition comprising 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm; and a mixed solvent composed of 10 wt% of ethanol and 85 wt% of distilled water.

[0108] <Comparative Preparation Example 2: Composition not containing functional nanoparticles>

[0109] A composition for forming surface roughness was prepared, which included a mixed solvent consisting of 70 wt% ethanol and 30 wt% distilled water.

[0110] <Comparative Preparation Example 3: Composition with excessively high alcohol content, unlike Comparative Preparation Example 1>

[0111] Average size (D 50 ) was prepared to form a surface roughness composition comprising 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm; and a mixed solvent composed of 90 wt% of ethanol and 5 wt% of distilled water.

[0112] <Preparation Examples 1-1 to 1-5: Composition containing radical scavenger>

[0113] (Example of implementation preparation 1-1)

[0114] Average size (D 50 ) was prepared as a composition for forming surface roughness of Example 1-1, which includes a mixed solvent consisting of 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm, 70 wt% of ethanol, and 25 wt% of distilled water.

[0115] (Example 1-2 for implementation)

[0116] Average size (D 50 ) was prepared as a composition for forming surface roughness of Example 1-2, which includes a mixed solvent consisting of 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm, 20 wt% of ethanol, and 75 wt% of distilled water.

[0117] (Example 1-3 for implementation)

[0118] Average size (D 50 ) was prepared as a composition for forming surface roughness of Example 1-3, which includes a mixed solvent consisting of 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm, 30 wt% of ethanol, and 65 wt% of distilled water.

[0119] (Example 1-4 for implementation)

[0120] Average size (D 50 ) was prepared as a composition for forming surface roughness of Example 1-4, which includes a mixed solvent consisting of 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm, 50 wt% of ethanol, and 45 wt% of distilled water.

[0121] (Example 1-5 for implementation)

[0122] Average size (D 50 ) was prepared as a composition for forming surface roughness of Example 1-5, which includes a mixed solvent consisting of 5 wt% of a radical scavenger (CeO2) having a particle size of 10 nm, 80 wt% of ethanol, and 15 wt% of distilled water.

[0123] <Preparation Example 2: Composition containing heat-radiating nanoparticles>

[0124] Average size (D 50 ) was prepared to form a surface roughness composition comprising 5 wt% of heat-radiating nanoparticles (h-BN) having a diameter of 150 nm; and a mixed solvent composed of 70 wt% of ethanol and 25 wt% of distilled water.

[0125] <Preparation Example 3: Composition containing hygroscopic nanoparticles>

[0126] BET surface area is 500m 2 / g, and the average size (D 50 ) was prepared to form a surface roughness composition comprising 5 wt% of hydrophilic nano-silica having a particle size of 60 nm; and a mixed solvent composed of 70 wt% of ethanol and 25 wt% of distilled water.

[0127] [Manufacturing Example 2: Manufacturing of a Polymer Electrolyte Membrane]

[0128] <Comparative Example 1: Preparation of a Commercial Polymer Electrolyte Membrane>

[0129] A commercial polymer electrolyte membrane was manufactured through a step of applying a polymer solution (solid concentration: 20 wt%) containing a mixed solvent of water and N-propanol in a weight ratio of 1:1 and perfluorosulfonic acid to a glass substrate using a doctor blade, and a step of slowly heating the applied polymer solution to 80°C and then drying it for 4 hours.

[0130] <Comparative Example 2: Polymer electrolyte membrane with surface roughness formed using the composition of Comparative Preparation Example 1>

[0131] The composition of Comparative Preparation Example 1 was coated on one side of the polymer electrolyte membrane according to Comparative Example 1 with a wet thickness of 100 μm (thickness before drying) using a slot die coating method, and then dried at 100°C for 300 seconds to manufacture a polymer electrolyte membrane having an irregular surface roughness (width: 0.2 μm / depth: 0.1 μm).

[0132] <Comparative Example 3: Polymer electrolyte membrane with surface roughness formed using the composition of Comparative Preparation Example 2>

[0133] The composition of Comparative Preparation Example 2 was coated on one side of the polymer electrolyte membrane according to Comparative Example 1 to a wet thickness of 100 μm using a slot die coating method, and then dried at 100°C for 200 seconds to manufacture a polymer electrolyte membrane having irregularly formed holes (width: 3 μm / depth: 1.5 μm).

[0134] <Comparative Example 4: Preparation of a polymer electrolyte membrane with surface roughness formed using the composition of Comparative Preparation Example 3>

[0135] A polymer electrolyte membrane was manufactured in the same manner as in Comparative Example 2, but the composition of Comparative Preparation Example 3 was used instead of the composition of Comparative Preparation Example 2.

[0136] <Examples 1-1 to 1-5: Polymer electrolyte membranes each having a surface roughness formed using the compositions of Preparation Examples 1-1 to 1-5>

[0137] Each of the compositions of Preparation Examples 1-1 to 1-5 was coated on one side of the polymer electrolyte membrane according to Comparative Example 1 to a wet thickness of 100 μm using a slot die coating method, and then dried at 100°C for 200 seconds to manufacture a polymer electrolyte membrane having irregularly formed holes (width: 3 μm / depth: 1.5 μm).

[0138] <Example 2: Polymer electrolyte membrane with surface roughness formed using the composition of Preparation Example 2>

[0139] The composition of the above Preparation Example 2 was coated on one side of the polymer electrolyte membrane according to the above Comparative Example 1 with a wet thickness of 100 μm using a slot die coating method, and then dried at 100°C for 200 seconds to manufacture a polymer electrolyte membrane having irregularly formed holes (width: 3 μm / depth: 1.5 μm).

[0140] <Example 3: Polymer electrolyte membrane with surface roughness formed using the composition of Preparation Example 3>

[0141] The composition of the above Preparation Example 3 was coated on one side of the polymer electrolyte membrane according to the above Comparative Example 1 with a wet thickness of 100 μm using a slot die coating method, and then dried at 100°C for 200 seconds to manufacture a polymer electrolyte membrane having irregularly formed holes (width: 3 μm / depth: 1.5 μm).

[0142] <Example 4: Polymer electrolyte membrane with surface roughness formed using the composition of Preparation Example 4>

[0143] The composition of the above Preparation Example 4 was coated on one side of the polymer electrolyte membrane according to the above Comparative Example 1 with a wet thickness of 100 μm using a slot die coating method, and then dried at 100°C for 200 seconds to manufacture a polymer electrolyte membrane having irregularly formed holes (width: 3 μm / depth: 1.5 μm).

[0144] [Experimental Example 1-1: Surface Roughness Measurement of Polymer Electrolyte Membranes]

[0145] Arithmetical average roughness (R) of the center line of the polymer electrolyte membrane (sample of 5 cm in width / length, respectively) manufactured by the method according to Comparative Examples 2 to 4, Examples 1-1 to 1-4, and 2 to 4 a ) was measured using Keyence's VK-X3000 equipment under standard non-contact measurement conditions at room temperature.

[0146] Meanwhile, the alcohol content in Table 1 below is a value set based on the total weight of the composition for forming surface roughness.

[0147] Content (weight%) of functional nanoparticle alcohol Center line average roughness (R a ) Comparative Example 2 Radical Scavenger 10 wt% 0.017 ㎛ Comparative Example 3 Not applicable 70 wt% 0.107 ㎛ Comparative Example 4 Radical Scavenger 90 wt% 0.394 ㎛ Example 1-1 Radical Scavenger 70 wt% 0.192 ㎛ Example 1-2 Radical Scavenger 20 wt% 0.111 ㎛ Example 1-3 Radical Scavenger 30 wt% 0.125 ㎛ Example 1-4 Radical Scavenger 50 wt% 0.155 ㎛ Example 1-5 Radical Scavenger 80 wt% 0.338 ㎛ Example 2 Heat-radiating nanoparticles 70 wt% 0.214 ㎛ Example 3 Hygroscopic nanoparticles 70 wt% 0.197 ㎛ Example 4 OER catalyst nanoparticles 70 Weight % 0.205㎛

[0148] [Experimental Example 1-2: Optical Microscope Photograph of Polymer Electrolyte Membrane]

[0149] Figure 3 is an optical microscope photograph of a polymer electrolyte membrane according to one embodiment of the present invention.

[0150] Referring to FIG. 3, it can be confirmed that the surface of the polymer electrolyte membrane according to one embodiment of the present invention includes holes.

[0151] [Manufacturing Example 3: Manufacturing of a Membrane-Electrode Assembly]

[0152] A Pt / C catalyst and a binder (Perfluorosulfonic acid, PFSA) were mixed in a weight ratio of 1:0.35 on both sides of the polymer electrolyte membrane according to the above Manufacturing Example 2, and an electrode slurry having a total solid content of 10 wt% was directly coated, and then dried to manufacture a membrane-electrode assembly.

[0153] [Experimental Example 2-1: SEM image of membrane-electrode assembly]

[0154] FIG. 4 is a scanning electron microscope (SEM) cross-sectional photograph of a membrane-electrode assembly according to one embodiment of the present invention.

[0155] Referring to Figure 4, it was confirmed that functional nanoparticles were loaded on a polymer electrolyte membrane in which holes were formed.

[0156] [Experimental Example 2-2: Evaluation of Membrane-Electrode Assemblies]

[0157] For the membrane-electrode assembly according to the above manufacturing example 3, the performance and durability were evaluated using the following measurement method, and the results are shown in Table 2 or 3 below.

[0158] 1) Performance

[0159] Under conditions of 80°C and atmospheric pressure, hydrogen (100% RH) and air (100% RH) were supplied to the anode and cathode in amounts corresponding to Stoichiometry 1.5 / 2.0, respectively, and the performance of the membrane-electrode assembly according to Manufacturing Example 3 was evaluated by measuring the voltage according to the current density using fuel cell unit cell evaluation equipment from Scitech.

[0160] Figure 5 is a graph showing the performance of membrane-electrode assemblies according to Comparative Examples 1 to 4 and Examples 1-1, 2 to 4.

[0161] Average roughness of the center line (R) a )Performance (mA / cm 2 @0.6V) Comparative Example 1 (Untreated) - 1100 Comparative Example 2 (Alcohol 10 wt%, CeO2) 0.017㎛ 1110 Comparative Example 3 (No functional particles) 0.107㎛ 1230 Comparative Example 4 (Alcohol 90 wt%, CeO2) 0.394㎛ 899 Example 1-1 (CeO2) 0.192㎛ 1220 Example 1-2 (CeO2) 0.111㎛ 1130 Example 1-3 (CeO2) 0.125㎛ 1170 Example 1-4 (CeO2) 0.155㎛ 1200 Example 1-5 (CeO2) 0.338㎛ 1050 Example 2 (h-BN) 0.214㎛ 1260 Example 3 (Silica) 0.197㎛1190 Example 4 (IrO2) 0.205㎛1190

[0162] Referring to Table 2 and FIG. 5, Comparative Example 2, in which the alcohol content was 10 wt% based on the total weight of the composition for forming surface roughness, exhibited a problem in that the centerline average roughness was not sufficiently increased, and thus the performance of the membrane-electrode assembly was not sufficiently improved. In addition, Comparative Example 4, in which the alcohol content was 90 wt% under the same criteria, exhibited a problem in that the centerline average roughness of the polymer electrolyte membrane surface was excessively increased, and thus the resistance increased, and the performance of the membrane-electrode assembly was lowered. On the other hand, Examples 1-1 to 1-5 exhibited an effect of improving the performance of the membrane-electrode assembly by satisfying an alcohol content of more than 10 wt% and less than 90 wt% based on the total weight of the composition for forming surface roughness.

[0163] In addition, when comparing Comparative Examples 2 and 4 and Example 1-1, it was confirmed that the centerline average roughness of the polymer electrolyte membrane was controlled, thereby affecting the functionality of the functional nanoparticle CeO2, which resulted in a change in the performance of the membrane-electrode assembly.

[0164] 2) Chemical durability

[0165] In accordance with the catalyst durability evaluation protocol of the U.S. Department of Energy (DOE), the voltage loss was measured by performing the OCV hold method under the conditions of 90°C, 30%RH, and 50kPa, and the results are shown in Fig. 6.

[0166] Figure 6 is a time-voltage loss graph of the membrane-electrode assembly according to Example 1-1 and Comparative Examples 2 and 3.

[0167] Referring to Fig. 6, Example 1-1 showed an effect of maintaining voltage for a longer period of time compared to Comparative Examples 2 and 3.

[0168] 3) Reverse voltage endurance

[0169] For the membrane-electrode assemblies according to the above examples and comparative examples, the reverse voltage durability was evaluated through a cell reversal test. Specifically, 50% RH air was supplied to the cathode, 50% RH nitrogen was supplied to the anode, and 0.2 A / cm 2 The reverse potential time, which is the time taken for the current to reach -2.0 V, was measured.

[0170] Comparison Example 1 Comparison Example 3 Example 4 Reverse potential time (min) 2 min 2 min 190 min

[0171] Referring to Table 3 above, Example 4, which has surface roughness through solution treatment including functional nanoparticles, exhibited excellent reverse potential durability with a higher reverse potential time compared to Comparative Examples 1 and 3. Through the above experimental results, the centerline average roughness (Arithmetic average roughness, R) of at least one side of the polymer electrolyte membrane a ) is adjusted, it can be confirmed that the performance or durability of the membrane-electrode assembly changes.

[0172] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0173] [Explanation of symbols]

[0174] 10: Polymer electrolyte membrane

[0175] 15: Functional nanoparticles

[0176] 20: Catalyst layer

[0177] 50: Membrane-electrode assembly

Claims

1. A polymer electrolyte membrane having at least one hole formed on at least one surface, At least one of the above one or more holes comprises a functional nanoparticle therein, Arithmetical average roughness (R) of the center line of at least one side of the polymer electrolyte membrane a ) is 0.11㎛ or more and 0.35㎛ or less, Polymer electrolyte membrane.

2. In paragraph 1, Each of the above holes, A depth of 0.5㎛ or more and 5㎛ or less, and a width of 0.2㎛ or more and 10㎛ or less, Polymer electrolyte membrane.

3. In paragraph 1, The above functional nanoparticles are, Comprising at least one member from the group consisting of radical scavengers, catalytic nanoparticles, heat-radiating nanoparticles and hygroscopic nanoparticles. Polymer electrolyte membrane.

4. In paragraph 1, The average size (D) of the above functional nanoparticles 50 ) is 5 nm or more and 170 nm or less, Polymer electrolyte membrane. 5.(S1) Step of preparing the description; and (S2) A step of manufacturing a polymer electrolyte membrane by coating and drying a composition for forming surface roughness on at least one side of the above-mentioned substrate; including; The composition for forming the above surface roughness is Containing functional nanoparticles and solvents, The above solvent is, Containing alcohol in an amount of more than 10 wt% and less than 90 wt% based on the total weight of the composition for forming the surface roughness, Method for manufacturing a polymer electrolyte membrane.

6. In paragraph 5, The content of the functional nanoparticles is 1 wt% or more and 10 wt% or less based on the total weight of the composition for forming the surface roughness. Method for manufacturing a polymer electrolyte membrane.

7. In paragraph 5, The above solvent is, Further comprising a polar solvent different from the above alcohol Method for manufacturing a polymer electrolyte membrane.

8. In paragraph 7, The above polar solvent is, Containing at least one selected from the group consisting of water, dimethylacetamide (DMAc), N-Methyl-2-Pyrrolidone (NMP), acetic acid, and propionic acid. Method for manufacturing a polymer electrolyte membrane.

9. In paragraph 5, The thickness of the composition for forming the above-mentioned coated surface roughness is 10 ㎛ or more and 150 ㎛ or less. Method for manufacturing a polymer electrolyte membrane.

10. A polymer electrolyte membrane according to any one of clauses 1 to 4; and A catalyst layer disposed on at least one surface of the polymer electrolyte membrane; Membrane-electrode assembly.

11. A fuel cell comprising a membrane-electrode assembly according to Article 10.

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