KR102321252B1 - Complex electrolyte membrane, manufacturing method thereof and membrane electrode assembly containing the same - Google Patents

Abstract

The present invention relates to a composite electrolyte membrane, a method for manufacturing the same, and a membrane-electrode assembly including the same, and more specifically, to a composite electrolyte membrane that has excellent durability and dimensional stability, improves gas permeability of oxygen (O_2), hydrogen (H_2) and the like, and has excellent performance, a method for manufacturing the same, and a membrane-electrode assembly including the same.

Description

Complex electrolyte membrane, manufacturing method thereof, and membrane-electrode assembly including the same

The present invention relates to a composite electrolyte membrane, a method for manufacturing the same, and a membrane-electrode assembly including the same, and more particularly, has excellent durability and dimensional stability as well as oxygen (O ₂ ), hydrogen (H ₂ ), etc. The present invention relates to a composite electrolyte membrane having improved gas permeability and excellent performance, a method for manufacturing the same, and a membrane-electrode assembly including the same.

A fuel cell is a power generation system that directly converts chemical energy generated by the electrochemical reaction of fuel (hydrogen or methanol) and oxidizing agent (oxygen) into electrical energy. is being researched and developed. Fuel cells can be used by selecting high-temperature and low-temperature fuel cells depending on the application field, and are generally classified according to the type of electrolyte. For high-temperature applications, solid oxide fuel cells (SOFC), molten carbonate There is a fuel cell (Molten Carbonate Fuel Cell, MCFC), and for low-temperature applications, an alkaline electrolyte fuel cell (AFC) and a polymer electrolyte fuel cell (PEMFC) are being developed.

In addition, as the amount of hydrogen used in fuel cells increases, hydrogen production using renewable energy is receiving a lot of attention. In particular, various water electrolysis systems using surplus electricity from solar power generation or wind power generation facilities are being developed. In addition, reforming technology that converts carbon dioxide generated from various sources such as flu gas and biogas into useful gas is also in the spotlight in terms of environmental conservation and energy utilization.

Water electrolysis is a method of producing hydrogen and oxygen by using electrons generated during the redox reaction of water. In the unit cell structure of water electrolysis, the anode and cathode are coated on both sides of the solid polymer electrolyte membrane composed of polymer materials, and the membrane electrode assembly and reactive gases are evenly distributed. It is composed of a gas diffusion layer that serves to transfer the generated electricity. At the anode, water is supplied and reacts on the electrocatalyst to generate oxygen, hydrogen ions and electrons. At the cathode, hydrogen ions passing through the solid polymer membrane combine with electrons to generate pure hydrogen.

On the other hand, if the double polymer electrolyte fuel cell is subdivided, a hydrogen ion exchange membrane fuel cell (PEMFC) that uses hydrogen gas as a fuel and liquid methanol are directly supplied to the anode as a fuel. Direct methanol fuel cell (DMFC) and the like. Polymer electrolyte fuel cells are attracting attention as portable, vehicle, and home power supplies due to their advantages such as a low operating temperature of less than 100°C, elimination of leakage problems due to the use of solid electrolytes, fast start-up and response characteristics, and excellent durability. In particular, as a high-output fuel cell having a higher current density than other types of fuel cells, research on a portable fuel cell is ongoing because it can be miniaturized.

The unit cell structure of such a fuel cell has a structure in which an anode (anode) and a cathode (cathode, an oxygen electrode) are coated on both sides of an electrolyte membrane composed of a polymer material, which is a membrane-electrode assembly (Membrane). Electrode Assembly (MEA). This membrane-electrode assembly (MEA) is a part where the electrochemical reaction of hydrogen and oxygen occurs, and is composed of a reducing electrode, an oxide electrode, and an electrolyte membrane, that is, an ion conductive electrolyte membrane (eg, a hydrogen ion conductive electrolyte membrane).

At the anode, hydrogen or methanol, which is a fuel, is supplied to cause an oxidation reaction of hydrogen to generate hydrogen ions and electrons. .

This membrane-electrode assembly has a form in which the electrode catalyst layers of the anode and the cathode are coated on both sides of the ion conductive electrolyte membrane, and the material constituting the electrode catalyst layer is Pt (platinum) or Pt-Ru (platinum-ruthenium), etc. of the catalyst material is supported on a carbon carrier. Membrane-electrode assembly (MEA), which can be seen as a key component of the electrochemical reaction of a fuel cell, uses an ion-conducting electrolyte membrane and a platinum catalyst, which have a high cost composition, and is directly related to power production efficiency. It is regarded as the most important part in improving the performance and price competitiveness of

The conventional method for manufacturing MEA, which is generally used, is to prepare a paste by mixing a catalyst material, a hydrogen ion conductive binder, that is, a fluorine-based Nafion ionomer, and water and / or an alcohol solvent, This is coated on carbon cloth or carbon paper that serves as an electrode support for supporting the catalyst layer and a gas diffusion layer at the same time, and then dried and thermally fused to a hydrogen ion conductive electrolyte membrane.

In the catalyst layer, the oxidation-reduction reaction of hydrogen and oxygen by a catalyst; movement of electrons by the adhered carbon particles; securing a passage for supplying hydrogen, oxygen and moisture and for discharging excess gas after reaction; The movement of oxidized hydrogen ions and the like must occur simultaneously. Moreover, in order to improve the performance, it is necessary to reduce the activation polarization by increasing the area of the triple phase boundary where the feed fuel meets the catalyst and the ion conductive polymer electrolyte membrane, and the interface between the catalyst layer and the electrolyte membrane and the catalyst layer It is necessary to uniformly bond the interface between the gas diffusion layer and the gas diffusion layer to reduce Ohmic polarization at the interface. Therefore, in order to improve the performance of the fuel cell by maximally reducing the interfacial resistance between the catalyst layer and the electrolyte membrane, there must be bonding strength between the catalyst layer and the electrolyte membrane during MEA manufacturing, as well as the interfacial bonding between the catalyst layer and the electrolyte membrane during fuel cell operation. should be maintained

Accordingly, in recent years, technology for uniformly bonding the interface between the catalyst layer and the electrolyte membrane and the interface between the catalyst layer and the gas diffusion layer has been actively developed, but the interface uniformity is still limited.

In addition, in the case of the MEA having the above-described structure, since an electrolyte membrane having a thick thickness is generally used, the transfer of hydrogen ions may be delayed, and thus performance may be deteriorated.

In addition, as the movement of hydrogen ions and the duration of use of the fuel cell increase, the interface between the catalyst layer and the electrolyte membrane and the interface between the catalyst layer and the gas diffusion layer are weakened, resulting in separation from each other. Accordingly, when applied to a fuel cell, the performance of the fuel cell may be deteriorated.

In order to shorten the movement time of hydrogen ions, etc., it is necessary to reduce the thickness of the electrolyte membrane, and for this purpose, there is a method of thinning the thickness of the porous support constituting the electrolyte membrane. In addition to this significantly reduced, there was a problem in that economical and commercial properties were lowered due to a high defect rate during the manufacture of the support.

Korean Patent Publication No. 2010-0077483 (published on: 2010.07.08) Korean Patent Publication No. 2019-0057787 (published on: May 29, 2019)

The present invention was devised in consideration of the above points, and by forming a composite electrolyte membrane in a multilayer structure, not only durability and dimensional stability are excellent, but also _{gas permeability of oxygen (O 2} ), hydrogen (H ₂ ), etc. is improved An object of the present invention is to provide a composite electrolyte membrane having excellent performance, a method for manufacturing the same, and a membrane-electrode assembly including the same.

In order to solve the above problems, the composite electrolyte membrane of the present invention may have a structure in which a first electrolyte layer, a first support layer, a second electrolyte layer, a second support layer, and a third electrolyte layer are sequentially stacked.

In a preferred embodiment of the present invention, the composite electrolyte membrane of the present invention is a composite electrolyte membrane in which a first electrolyte layer, a first support layer, a second electrolyte layer, a second support layer and a third electrolyte layer are sequentially stacked, The composite electrolyte membrane may have a dimensional change rate in the MD direction of 10% or less and a dimensional change rate in the TD direction of 10% or less, as measured by the following relational equation (2).

[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.

In a preferred embodiment of the present invention, the composite electrolyte membrane of the present invention may have a dimensional change rate in the MD direction of 0 to 3% and a dimensional change rate in the TD direction of 0 to 3%, as measured by Equation 2 above.

In a preferred embodiment of the present invention, each of the first support layer and the second support layer includes a PTFE porous support, and the PTFE porous support of the first support layer has a rate of dimensional change in the MD direction measured by the following Relation 1 This 3% or less, the dimensional change rate in the TD direction is 10% or less, the PTFE porous support of the second support layer has a dimensional change rate in the MD direction of 10% or less, and a dimensional change rate in the TD direction measured by the following relation 1 may be below.

[Relational Expression 1]

In Relation 1, A represents the initial length of the porous PTFE support, and B represents the length measured after the PTFE porous support was left at a temperature of 80° C. for 20 minutes.

In a preferred embodiment of the present invention, the PTFE porous support of the first support layer has a dimensional change rate in the MD direction of 0.5 to 2.5%, and a dimensional change rate in the TD direction of 3.5% to 7.5%, measured by Relation 1, and , The PTFE porous support of the second support layer may have a dimensional change rate in the MD direction of 3.5 to 7.5%, and a dimensional change rate in the TD direction of 0.5% to 2.5%, measured by Equation 1 above.

In a preferred embodiment of the present invention, the composite electrolyte membrane of the present invention may be for PEMFC (Polymer Electrolyte Membrane Fuel Cell) or for water electrolysis.

In a preferred embodiment of the present invention, the composite electrolyte membrane of the present invention may further include a third support layer formed on one surface of the third electrolyte layer and a fourth electrolyte layer formed on one surface of the third support layer.

In a preferred embodiment of the present invention, the first electrolyte layer may include a perfluorinated sulfonated ionomer.

In a preferred embodiment of the present invention, the second electrolyte layer may include a perfluorinated sulfonated ionomer.

In a preferred embodiment of the present invention, the third electrolyte layer may include a perfluorinated sulfonated ionomer.

In a preferred embodiment of the present invention, the first electrolyte layer may include a radical scavenger.

In a preferred embodiment of the present invention, the second electrolyte layer may include a radical scavenger.

In a preferred embodiment of the present invention, the third electrolyte layer may include a radical scavenger.

In a preferred embodiment of the present invention, the first electrolyte layer may have an _{equivalent weight of -SO 3} H group (EW: equivalent weight) of 700 to 1200.

In a preferred embodiment of the present invention, the second electrolyte layer may have an _{equivalent weight of -SO 3} H group (EW: equivalent weight) of 900 or less.

In a preferred embodiment of the present invention, the third electrolyte layer may have an _{equivalent weight of -SO 3} H group (EW: equivalent weight) of 700 to 1200.

In a preferred embodiment of the present invention, the radical scavenger is CeZnO, CeO ₂ , Ru, Ag, RuO ₂ , WO ₃ , Fe ₃ O ₄ , CePO ₄ , CrPO ₄ , AlPO ₄ , FePO ₄ , CeF ₃ , FeF ₃ , Ce ₂ (CO ₃ ) ₃ ·8H ₂ O, Ce(CHCOO) ₃ ·H ₂ O, CeCl ₃ ·6H ₂ O, Ce(NO ₃ ) ₆ ·6H ₂ O, Ce(NH ₄ ) ₂ ( NO ₃ ) ₆ , Ce(NH ₄ ) ₄ (SO ₄ ) ₄ .4H ₂ O, and Ce(CH ₃ COCHCOCH ₃ ) _{3 .3H 2} O may be included.

In a preferred embodiment of the present invention, the first support layer may include a PTFE porous support having an average pore size of 0.080 to 0.200 μm and an average porosity of 60 to 90%.

In a preferred embodiment of the present invention, the second support layer may include a PTFE porous support having an average pore size of 0.080 to 0.200 μm and an average porosity of 60 to 90%.

On the other hand, the method of manufacturing a composite electrolyte membrane of the present invention includes a first step of preparing a first support layer and a second support layer, respectively, forming a first electrolyte layer on one surface of the first support layer, and on one surface of the second support layer A second step of forming a third electrolyte layer, a third step of forming a second electrolyte layer on the other surface of the first support layer, and laminating the second electrolyte layer on the other surface of the second support layer and heat-treating the first electrolyte A fourth step of manufacturing a composite electrolyte membrane in which a layer, a first support layer, a second electrolyte layer, a second support layer, and a third electrolyte layer are sequentially stacked, wherein the composite electrolyte membrane has an MD measured by the following Relation 2 The dimensional change rate in the direction may be 10% or less, and the dimensional change rate in the TD direction may be 10% or less.

[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.

Furthermore, the membrane-electrode assembly of the present invention includes an anode (anode electrode); It may include a composite electrolyte membrane and a cathode (reducing electrode) of the present invention.

On the other hand, the polymer electrolyte membrane fuel cell of the present invention includes the membrane-electrode assembly and the separator of the present invention, and includes an electricity generator that generates electricity through an electrochemical reaction of a fuel and an oxidizer, and a fuel that supplies the fuel to the electricity generator. supply; and an oxidizing agent supply unit for supplying the oxidizing agent to the generator.

The composite electrolyte membrane of the present invention, a method for manufacturing the same, and a membrane-electrode assembly including the same have excellent durability and dimensional stability, as well as improved gas permeability such _{as oxygen (O 2} ), hydrogen (H _{2 ), and performance} great.

In addition, the composite electrolyte membrane of the present invention, a method for manufacturing the same, and a membrane-electrode assembly including the same can be used for PEMFC (Polymer Electrolyte Membrane Fuel Cell) or for water electrolysis.

1 is a schematic diagram of a composite electrolyte membrane according to a preferred embodiment of the present invention.
2 is a schematic diagram of a composite electrolyte membrane according to another preferred embodiment of the present invention.
3 is a schematic diagram of a composite electrolyte membrane according to another preferred embodiment of the present invention.
4 is a schematic diagram of a membrane-electrode assembly according to a preferred embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar elements throughout the specification.

The composite electrolyte membrane of the present invention may be for PEMFC (Polymer Electrolyte Membrane Fuel Cell) or for water electrolysis, preferably for PEMFC (Polymer Electrolyte Membrane Fuel Cell).

Referring to FIG. 1 , the composite electrolyte membrane of the present invention includes a first electrolyte layer 21 , a first support layer 11 , a second electrolyte layer 22 , a second support layer 12 , and a third electrolyte layer 23 . ) may have a sequentially stacked structure.

Specifically, the composite electrolyte membrane of the present invention includes a first electrolyte layer 21 , a first support layer 11 formed on one surface of the first electrolyte layer 21 , and a second electrolyte formed on one surface of the first support layer 11 . It may include a layer 22 , a second support layer 12 formed on one surface of the second electrolyte layer 22 , and a third electrolyte layer 23 formed on one surface of the second support layer 12 .

First, each of the first support layer 11 and the second support layer 12 of the present invention may use a general porous support used in the art, preferably PTFE ( Polytetrafluoroethylene) may include a porous support.

The PTFE porous support of the present invention is prepared by mixing and stirring PTFE powder and a lubricant in step 1-1 to prepare a paste; Step 1-2 of aging the paste; Steps 1-3 of extruding and rolling the aged paste to prepare an unfired tape; After drying the unbaked tape, steps 1-4 of removing the liquid lubricant; Steps 1-5 of uniaxially stretching the unbaked tape from which the lubricant has been removed; Steps 1-6 of biaxially stretching the uniaxially stretched unbaked tape; and steps 1-7 of calcining.

In step 1-1, the paste may contain 15 to 35 parts by weight of a lubricant, preferably 15 to 30 parts by weight, and more preferably 15 to 25 parts by weight based on 100 parts by weight of the PTFE powder. When the lubricant is less than 15 parts by weight based on 100 parts by weight of the PTFE powder, the porosity may be lowered when the PTFE porous support is formed by the biaxial stretching process to be described later, and when it exceeds 35 parts by weight, the size of the pores when the PTFE porous support is formed It may become large and the strength of the support may be weakened.

The average particle diameter of the PTFE powder is 300㎛ ~ 800㎛. Preferably, it may be 450 μm to 700 μm, but is not limited thereto. The lubricant is a liquid lubricant, and in addition to hydrocarbon oils such as liquid paraffin, naphtha, white oil, toluene, and xylene, various alcohols, ketones, esters, etc. may be used, and preferably liquid paraffin, naphtha and white oil. One or more types may be used.

Next, the aging of step 1-2 is a preforming process, and the paste may be aged for 12 to 24 hours at a temperature of 30° C. to 70° C., preferably 16 to at a temperature of 35° C. to 60° C. It can be aged for 20 hours. When the aging temperature is less than 35° C. or the aging time is less than 12 hours, the lubricant coating becomes non-uniform on the surface of the PTFE powder, so that the stretching uniformity of the PTFE porous support may be limited during biaxial stretching, which will be described later.

In addition, when the aging temperature exceeds 70° C. or the aging time exceeds 24 hours, there may be a problem in that the pore size of the PTFE porous support after the biaxial stretching process is too small due to evaporation of the lubricant.

Next, in the extrusion of steps 1-3, a PTFE block is prepared by compressing the aged paste in a compressor, and then the PTFE block is ^{pressed at a pressure of 0.069 to 0.200 Ton/cm 2} , preferably 0.090 to 0.175 Ton/cm It can be carried out by pressure extrusion at a pressure of ^2.

At this time, when the pressure-extrusion pressure is ^{less than 0.069 Ton/cm 2} , the pore size of the porous support increases and the strength of the porous support may be weakened, and ^{when it exceeds 0.200 Ton/cm 2} , the pore size of the porous support after the biaxial stretching process There may be a problem with the .

In addition, the rolling of steps 1-3 may be performed by a calendering process at 50 to 100° C. with a hydraulic pressure of 5 to 10 MPa. At this time, when the hydraulic pressure is less than 5 MPa, the pore size of the porous support may be increased, and thus the strength of the porous support may be weakened.

Next, the drying of steps 1-4 can be performed through a general drying method used in the art, and for example, the unbaked tape prepared by rolling is 1 to 5M/ While conveying to the conveyor belt at a speed of min, it can be carried out while conveying, preferably at a temperature of 140 ℃ ~ 190 ℃ 2 ~ 4M / min at a speed. At this time, if the drying temperature is 100° C. or less or the drying rate exceeds 5 M/min, bubbles may be generated during the stretching process due to non-evaporation of the lubricant, and the drying temperature is 200° C. or more or the drying rate is 1 M/min. If min is less than the stiffness of the dried tape increases, slip may occur during the stretching process.

Next, the uniaxial stretching of steps 1-5 is a process of stretching the unbaked tape from which the lubricant has been removed in the longitudinal direction. When transported through the rollers, the uniaxial stretching is performed using the speed difference between the rollers. . And, the uniaxial stretching is 3 to 10 times, preferably 6 to 9.5 times, more preferably 6.2 to 9 times, even more preferably 6.3 to 8.2 times the stretching of the unbaked tape from which the lubricant is removed in the longitudinal direction. It is good to do At this time, if the uniaxial stretching ratio is less than 3 times, sufficient mechanical properties cannot be secured, and if the uniaxial stretching ratio exceeds 10 times, the mechanical properties are rather decreased, and there may be a problem in that the pores of the support become too large.

In addition, uniaxial stretching is performed at a stretching temperature of 260 ° C. to 350 ° C. and a stretching rate of 6 to 12 M / min, preferably a stretching temperature of 270 ° C. to 330 ° C. and a stretching rate of 8 to 11.5 M / min. Preferably, if the stretching temperature is less than 260°C during uniaxial stretching or if the stretching speed is less than 6 M/min, there may be a problem that a firing section occurs due to a large amount of heat applied to the dry sheet, and the stretching temperature during uniaxial stretching If is over 350 ℃ or the stretching speed exceeds 12 M/min, slip occurs during the uniaxial stretching process, there may be a problem that the thickness uniformity is lowered.

Next, in the biaxial stretching of steps 1-6, stretching is performed in the width direction (direction perpendicular to the uniaxial stretching) of the uniaxially stretched unbaked tape, and the width is widened in the lateral direction while the end is fixed. can be stretched However, the present invention is not limited thereto, and may be stretched according to a stretching method commonly used in the art. In the present invention, the biaxial stretching may be performed at 15 to 50 times in the width direction, preferably 25 to 45 times, more preferably 28 to 45 times, still more preferably 29 to 42 times. In this case, if the biaxial stretching ratio is 15 times or less, sufficient mechanical properties may not be secured, and even if it exceeds 50 times, there is no improvement in mechanical properties, and the uniformity of physical properties in the longitudinal direction and/or the width direction is lowered. Since there may be, it is preferable to perform stretching within the above range.

In addition, the biaxial stretching is carried out at a stretching rate of 10 to 20 M/min under a stretching temperature of 150° C. to 260° C., preferably at a stretching rate of 11 to 18 M/min under a stretching temperature of 200° C. to 250° C. If the biaxial stretching temperature is less than 150 ℃ or the stretching speed is less than 10 M/min, there may be a problem that the stretching uniformity in the transverse direction is lowered, and the biaxial stretching temperature exceeds 260 ℃, or When the stretching speed exceeds 20 M/min, there may be a problem in that an unbaked section occurs and the physical properties are deteriorated.

Finally, the firing of steps 1-7 moves the stretched porous support on a conveyor belt at a speed of 10 to 18 M/min, preferably at a speed of 13 to 17 M/min, at 350° C. to 450° C., Preferably, a temperature of 380 ° C. to 440 ° C., and more preferably a temperature of 400 ° C. to 435 ° C. may be applied, thereby fixing the draw ratio and improving the strength. During calcination, if the calcination temperature is less than 350 ° C., the strength of the porous support may be lowered, and if it exceeds 450 ° C., there may be a problem in that the physical properties of the support are lowered due to a decrease in the number of fibrils due to underfiring.

In addition, the PTFE porous support prepared by performing the process of steps 1-7 has a draw ratio (or aspect ratio) in the uniaxial direction (length direction) and biaxial direction (width direction) of 1:3.00 to 8.5, preferably 1 : 4.0 to 7.0, more preferably 1: 4.00 to 5.50, even more preferably 1: 4.20 to 5.00, and the uniaxial and biaxial stretching ratios (or aspect ratios) are high in the above ranges. It is preferable in terms of mechanical properties, securing an appropriate pore size of the support, and securing an appropriate current flow.

The prepared PTFE porous support of the present invention may have an average pore size of 0.080 μm to 0.200 μm, preferably 0.090 μm to 0.180 μm, more preferably 0.095 μm to 0.150 μm, even more preferably 0.100 to 0.140 μm. . In addition, the PTFE porous support of the present invention may have an average porosity of 60% to 90%, more preferably 60% to 79.6%.

If the average pore size of the PTFE porous support of the present invention is less than 0.080 μm or the porosity is less than 60%, the degree of impregnation of the electrolyte in the PTFE porous support is limited when impregnated with the electrolyte to prepare an electrolyte membrane using the PTFE porous support. can In addition, when the average pore size exceeds 0.200 μm or the porosity exceeds 90%, the PTFE porous support structure is deformed when impregnated with an electrolyte, and there may be a problem in that the product life is reduced due to a decrease in dimensional stability.

Meanwhile, in the PTFE porous support of the present invention, when measured according to ASTM D 882, uniaxial modulus and biaxial modulus values may satisfy Equation 1 below.

[Equation 4]

0 ≤ │(uniaxial modulus - biaxial modulus)/(uniaxial modulus)×100%│ ≤ 54%, preferably 0 ≤ │(uniaxial modulus - biaxial modulus)/(uniaxial modulus) directional modulus)×100%│ ≤ 40%, more preferably 1 ≤ │(uniaxial modulus - biaxial modulus)/(uniaxial modulus)×100%│ ≤ 26%

In addition, the PTFE porous support of the present invention may have a uniaxial (lengthwise) modulus of 40 MPa or more, preferably a uniaxial direction modulus of 50 MPa or more, more Preferably, the uniaxial modulus may be 48 to 75 Mpa, more preferably 65 to 75 Mpa. In addition, the modulus in the biaxial direction (width direction) is 40 MPa or more, preferably the modulus in the biaxial direction (width direction) is 55 Mpa or more, more preferably 46 to 75 Mpa, even more preferably 55 to 75 Mpa. can

In addition, the PTFE porous support of the present invention may have a uniaxial (length direction) tensile strength of 40 MPa or more and a biaxial direction (width direction) tensile strength of 40 MPa or more, preferably 1 The tensile strength in the axial direction may be 50 MPa or more, and more preferably, the tensile strength in the uniaxial direction may be 54 to 65 Mpa. Also, preferably, the tensile strength in the biaxial direction may be 52 Mpa or more, and more preferably, the tensile strength in the biaxial direction may be 52 to 70 Mpa.

On the other hand, the PTFE porous support of the present invention may have various dimensional change rates according to the uniaxial stretching ratio and/or the biaxial stretching ratio.

Specifically, when the PTFE porous support of the present invention is used as the first support layer 11 of the present invention, the first support layer 11 has a dimensional change rate in the MD direction (= lengthwise direction) measured by the following relation 1 3% or less, preferably 0.5 to 2.5%, more preferably 0.5 to 1.5%, and the dimensional change rate in the TD direction (= width direction) measured by the following relation 1 is 10% or less, preferably 3.5 -7.5%, more preferably 4.5-5.5%.

[Relational Expression 1]

In Relation 1, A represents the initial length of the porous PTFE support, and B represents the length measured after the PTFE porous support was left at a temperature of 80° C. for 20 minutes.

In addition, when the PTFE porous support of the present invention is used as the second support layer 12 of the present invention, the second support layer 12 has a dimensional change rate in the MD direction (= longitudinal direction) measured by the above relation 1 is 10 % or less, preferably 3.5 to 7.5%, more preferably 4.5 to 5.5%, and the dimensional change rate in the TD direction (= width direction) measured by the above relation 1 is 3% or less, preferably 0.5 to It may be 2.5%, more preferably 0.5 to 1.5%.

If the composite electrolyte membrane of the present invention uses the first support layer 11 and/or the second support layer 12 that deviates from the above-mentioned dimensional change rates in the MD and TD directions, dimensional stability and durability are reduced. there may be

On the other hand, each of the first support layer 11 and the second support layer 12 of the present invention has a thickness of 1 to 24 μm, preferably 2 to 20 μm, more preferably 3 to 15 μm, Even more preferably, it may have a thickness of 3 to 10 μm, and even more preferably 4 to 7 μm, and if the thickness is less than 1 μm, there may be a problem in that the tensile strength decreases, and if it exceeds 24 μm, the thickness is increased. There may be problems that are difficult to control.

Next, each of the first electrolyte layer 21 , the second electrolyte layer 22 , and the third electrolyte layer 23 of the present invention may include a perfluorinated sulfonated ionomer (PFSA ionomer).

The perfluorinated sulfonated ionomer of the present invention may include at least one selected from Nafion, Flemion, Aquivion, and Aciplex, and preferably Aquivion (aquivion). ) may be included.

In addition, the perfluorinated sulfonated ionomer not only constitutes each of the first electrolyte layer 21 , the second electrolyte layer 22 , and the third electrolyte layer 23 , but also the first support layer 11 and/or the second electrolyte layer 23 . It may be included in the pores of the support layer 12 .

Meanwhile, each of the first electrolyte layer 21, the second electrolyte layer 22, and the third electrolyte layer 23 of the present invention may further include a radical scavenger in addition to the perfluorinated sulfonated ionomer. .

The radical scavenger of the present invention _{mixes a Ce precursor aqueous solution with a [Zn(OH) 4} ] ^2- containing solution and performs a reduction reaction to obtain CeZnO metal oxide particles having a cerium ion-doped ZnO crystal structure. It can be produced by forming. Here, the "ZnO crystal structure doped with Ce ions" means that a crystal structure in which some of Zn atoms are substituted with Ce atoms in a ZnO crystal structure having a crystal structure such as wurtzite is newly formed.

To explain this in more detail, a first step of dissolving a Zn precursor in alcohol to prepare a Zn precursor solution, and then heating the Zn precursor solution; [Zn(OH) ₄ ] A second step of preparing a ^{2-containing solution;} [Zn(OH) ₄ ] A third step of forming CeZnO metal oxide particles having a ZnO crystal structure doped with Ce ions by mixing and reducing a Ce precursor aqueous solution in a ^{2-containing solution;} a fourth step of recovering and washing the CeZnO metal oxide particles; and a fifth step of drying the washed CeZnO metal oxide particles. For a more detailed description of this, Korean Patent Registration No. 10-1860870 by the same applicant may be inserted as a reference.

The radical scavenger of the present invention is a metal oxide particle having a crystal structure composed of a cerium (Ce) atom, a zinc (Zn) atom and an oxygen (O) atom. The branch may have a crystal structure in which some of the Zn atoms are substituted with Ce atoms in the ZnO crystal structure.

In addition, the radical scavenger of the present invention is CeZnO, CeO ₂ , Ru, Ag, RuO ₂ , WO ₃ , Fe ₃ O ₄ , CePO ₄ , CrPO ₄ , AlPO ₄ , FePO ₄ , CeF ₃ , FeF ₃ , Ce ₂ (CO ₃ ) ₃ ·8H ₂ O, Ce(CHCOO) ₃ ·H ₂ O, CeCl ₃ ·6H ₂ O, Ce(NO ₃ ) ₆ ·6H ₂ O, Ce(NH ₄ ) ₂ (NO ₃ ) ₆ , Ce(NH ₄ ) ₄ (SO ₄ ) ₄ .4H ₂ O and Ce(CH ₃ COCHCOCH ₃ ) _{3 .3H 2} O may be included.

In addition, the radical scavenger of the present invention may include 12 to 91% by weight of Ce, 7 to 84.5% by weight of Zn, and the remaining amount of O, preferably 13.40 to 89.20% by weight of Ce, 7.55 to 88.20% by weight of Zn and A residual amount of O may be included. And, it may further include other unavoidable impurities.

In addition, the radical scavenger of the present invention may be 500 nm or less, preferably 300 nm or less, more preferably 200 to 300 nm when the particle size (D50) is analyzed with a DLS (Dynamic Light Scattering) type nano particle size analyzer. .

Meanwhile, each of the first electrolyte layer 21, the second electrolyte layer 22 and the third electrolyte layer 23 of the present invention contains 0.001 to 10 parts by weight of a radical scavenger based on 100 parts by weight of the perfluorinated sulfonated ionomer, Preferably it may contain 0.01 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, and if it contains less than 0.001 parts by weight, there may be a problem of poor durability, and if it exceeds 10 parts by weight, the durability is improved. , there may be a problem in that the performance of the composite electrolyte membrane of the present invention is deteriorated due to low ionic conductivity.

Furthermore, each of the first electrolyte layer 21 , the second electrolyte layer 22 , and the third electrolyte layer 23 of the present invention may further include hollow silica.

The hollow silica is spherical, and may have an average particle diameter of 10 to 300 nm, more preferably 10 to 100 nm. Here, the particle size means the diameter when the shape of the hollow silica is spherical, and when the shape of the hollow silica is not spherical, it means the maximum distance among the linear distances from any one point on the surface of the hollow silica to another point.

In addition, each of the first electrolyte layer 21, the second electrolyte layer 22, and the third electrolyte layer 23 of the present invention may further include at least one desiccant selected from zeolite, titania, zirconia, and montmorillonite.

Meanwhile, each of the first electrolyte layer 21, the second electrolyte layer 22 and the third electrolyte layer 23 of the present invention has a thickness of 6 to 50 μm, preferably 10 to 40 μm, more preferably may have a thickness of 15 to 30 μm, more preferably a thickness of 20 to 26 μm, and if the thickness is less than 6 μm, there may be a problem of a decrease in tensile strength, and if it exceeds 50 μm, control the thickness There can be tough problems.

In addition, each of the first electrolyte layer 21 and the third electrolyte layer 23 of the present invention has an _{equivalent weight of -SO 3} H group (EW) of 700 to 1200, preferably 800 to 1100, more preferably may be 900 to 1050, more preferably 950 to 1000, and if _{the equivalent of -SO 3} H group is less than 700, there may be a problem of reduced durability, and if it exceeds 1200, there may be a problem of performance degradation. have.

In addition, the second electrolyte layer 22 of the present invention has an _{equivalent weight of -SO 3} H group (EW: equivalent weight) of 900 or less, preferably 500 to 900, more preferably 600 to 830, still more preferably 680 It may be ~ 750, and if _{the equivalent of the -SO 3} H group exceeds 900, there may be a problem of performance degradation.

Furthermore, in the composite electrolyte membrane of the present invention, the dimensional change rate in the MD direction (= longitudinal direction) measured by the following relation 2 is 10% or less, preferably 0 to 5%, more preferably 0 to 3%, still more preferably may be 0.5 to 2%, and the rate of dimensional change in the TD direction (=width direction) measured by the following relation 2 is 10% or less, preferably 0 to 5%, more preferably 0 to 3%, still more preferably For example, it may be 0.5 to 2%.

[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.

As such, the composite electrolyte membrane of the present invention exhibits a low rate of dimensional change not only in the MD direction but also in the TD direction, and thus has remarkably excellent dimensional stability.

In addition, the composite electrolyte membrane of the present invention may satisfy the following condition (1).

(1) E ₁ > E _2, E ₃ > E ₂

In the above condition _(1), E 1 is the first group equivalent weight of the electrolyte layer (21) -SO ₃ H a, E ₂ is a group equivalent weight of the second electrolyte layer (22) -SO ₃ H a, E ₃ is the 3 The equivalent of the -SO ₃ H group in the electrolyte layer 23 is shown.

If the composite electrolyte membrane of the present invention does not satisfy condition (1), there may be a problem of reduced performance.

In addition, the composite electrolyte membrane of the present invention may satisfy the following condition (2).

≤ 4, 바람직하게는 2.2 ≤

≤ 3.5, 더욱 바람직하게는 2.4 ≤

≤ 3.2, 더더욱 바람직하게는 2.5 ≤

≤ 2.9, 더더더욱 바람직하게는 2.6 ≤

≤ 2.8(2) 2 <

≤ 4, preferably 2.2 ≤

≤ 3.5, more preferably 2.4 ≤

≤ 3.2, even more preferably 2.5 ≤

≤ 2.9, even more preferably 2.6 ≤

≤ 2.8

In the above condition (2), E ₁ is the first group equivalent weight of the electrolyte layer (21) -SO ₃ H a, E ₂ is a group equivalent weight of the second electrolyte layer (22) -SO ₃ H a, E ₃ is the 3 The equivalent of the -SO ₃ H group in the electrolyte layer 23 is shown.

이 2 이하이면 성능이 저하되는 문제가 있을 수 있고, 4를 초과하면 내구성이 저하되는 문제가 있을 수 있다.If in condition (2),

If it is 2 or less, there may be a problem that performance is lowered, and if it exceeds 4, there may be a problem that durability is lowered.

In addition, the composite electrolyte membrane of the present invention has an oxygen permeability measured according to ASTM D 1434 of 2,000 GTR (cm ³ /m ² ·24h·0.1MPa) or less, preferably 0 to 1,700 GTR, more preferably 50 to 1,500 GTR, still more preferably 50 to 360 GTR, even more preferably 50 to 300 GTR, even more preferably 50 to 250 GTR, even more preferably 50 to 200 GTR.

On the other hand, the composite electrolyte membrane of the present invention may have an average thickness of 50 to 200 μm, preferably 60 to 150 μm, more preferably 70 to 120 μm, still more preferably 70 to 100 μm, and if the average thickness is 50 If it is less than μm, there may be a problem in that gas permeability increases, and if it exceeds 200 μm, there may be a problem in that economic efficiency is lowered.

In addition, the composite electrolyte membrane of the present invention may satisfy both conditions (3) and (4).

(3) B ₁ ≤ A ₁ , B ₁ ≤ A ₂ , B ₁ ≤ A ₃

(4) B ₂ ≤ A ₁ , B ₂ ≤ A ₂ , B ₂ ≤ A ₃

In the above condition (3), A ₁ is the thickness of the first electrolyte layer 21, A ₂ is the thickness of the second electrolyte layer 22, A ₃ is the thickness of the third electrolyte layer 23, B ₁ is represents the thickness of the first support layer 11 , and in the above condition (4), A ₁ is the thickness of the first electrolyte layer 21 , A ₂ is the thickness of the second electrolyte layer 22 , and A ₃ is the thickness of the second electrolyte layer 22 . 3 The thickness of the electrolyte layer 23 , B ₂ represents the thickness of the second support layer 12 .

If the composite electrolyte membrane of the present invention does not satisfy both conditions (3) and (4), there may be a problem of reduced uniformity.

In addition, the composite electrolyte membrane of the present invention may satisfy condition (5).

≤ 12, 바람직하게는 2 ≤

≤ 9, 더욱 바람직하게는 3 ≤

≤ 8, 더더욱 바람직하게는 5 ≤

≤ 7.5, 더더더욱 바람직하게는 6.5 ≤

≤ 7.5(5) 1.5 ≤

≤ 12, preferably 2 ≤

≤ 9, more preferably 3 ≤

≤ 8, even more preferably 5 ≤

≤ 7.5, even more preferably 6.5 ≤

≤ 7.5

In the above condition (5), A ₁ is the thickness of the first electrolyte layer 21, A ₂ is the thickness of the second electrolyte layer 22, A ₃ is the thickness of the third electrolyte layer 23, B ₁ is The thickness of the first support layer 11 , B ₂ represents the thickness of the second support layer 12 .

이 1.5 미만이면 복합 전해질막이 제조되는 않는 문제가 있을 수 있고, 12를 초과하면 내구성이 저하되는 문제가 있을 수 있다.If in condition (5),

If it is less than 1.5, there may be a problem in that the composite electrolyte membrane is not manufactured, and if it exceeds 12, there may be a problem in that durability is reduced.

In addition, the composite electrolyte membrane of the present invention may satisfy condition (6).

≤ 10, 바람직하게는 0.5 ≤

≤ 8, 더욱 바람직하게는 1.0 ≤

≤ 6, 더더욱 바람직하게는 1.5 ≤

≤ 3, 더더더욱 바람직하게는 2.0 ≤

≤ 2.4(6) 0.2 ≤

≤ 10, preferably 0.5 ≤

≤ 8, more preferably 1.0 ≤

≤ 6, even more preferably 1.5 ≤

≤ 3, even more preferably 2.0 ≤

≤ 2.4

In the above condition (6), A ₁ is the thickness of the first electrolyte layer 21 , A ₂ is the thickness of the second electrolyte layer 22 , and A ₃ is the thickness of the third electrolyte layer 23 .

이 0.2 미만이면 내구성이 저하되는 문제가 있을 수 있고, 10를 초과하면 성능이 감소하는 문제가 있을 수 있다.If in condition (6),

If it is less than 0.2, there may be a problem of lowering durability, and if it exceeds 10, there may be a problem of reduced performance.

Meanwhile, referring to FIG. 2 , the composite electrolyte membrane of the present invention includes a first electrolyte layer 21 , a first support layer 11 , a second electrolyte layer 22 , a second support layer 12 , and a third electrolyte layer. (23), the third support layer 13 and the fourth electrolyte layer 24 may have a structure in which they are sequentially stacked.

Specifically, the composite electrolyte membrane of the present invention includes a first electrolyte layer 21 , a first support layer 11 formed on one surface of the first electrolyte layer 21 , and a second electrolyte formed on one surface of the first support layer 11 . Layer 22, a second support layer 12 formed on one surface of the second electrolyte layer 22, a third electrolyte layer 23 formed on one surface of the second support layer 12, and the third electrolyte layer 23 ) may include a third support layer 13 formed on one surface and a fourth electrolyte layer 24 formed on one surface of the third support layer 13 . In this case, the third support layer 13 may be the same as the first support layer 11 and/or the second support layer 12 described above, and the fourth electrolyte layer 24 is the first electrolyte layer described above. (21), the second electrolyte layer 22 and/or the third electrolyte layer 23 may be the same.

Furthermore, referring to FIG. 3 , the composite electrolyte membrane of the present invention includes a fifth electrolyte layer 25 , a fourth support layer 14 , a first electrolyte layer 21 , a first support layer 11 , and a second electrolyte layer. (22), the second support layer 12, the third electrolyte layer 23, the third support layer 13, and the fourth electrolyte layer 24 may have a structure in which they are sequentially stacked.

Specifically, the composite electrolyte membrane of the present invention includes a fifth electrolyte layer 25 , a fourth support layer 14 formed on one surface of the fifth electrolyte layer 25 , and a first electrolyte formed on one surface of the fourth support layer 14 . layer 21 , a first support layer 11 formed on one surface of the first electrolyte layer 21 , a second electrolyte layer 22 formed on one surface of the first support layer 11 , and the second electrolyte layer 22 ) a second support layer 12 formed on one surface, a third electrolyte layer 23 formed on one surface of the second support layer 12, a third support layer 13 formed on one surface of the third electrolyte layer 23, and A fourth electrolyte layer 24 formed on one surface of the third support layer 13 may be included. In this case, the fourth support layer 13 may be the same as the first support layer 11 , the second support layer 12 , and/or the third support layer 13 described above, and the fifth electrolyte layer 25 . ) may be the same as those of the first electrolyte layer 21 , the second electrolyte layer 22 , the third electrolyte layer 23 , and/or the fourth electrolyte layer 24 described above.

Furthermore, referring to FIG. 4 , the membrane-electrode assembly of the present invention includes an anode (oxidation electrode) 200 , the composite electrolyte membrane 100 of the present invention described above, and a cathode (reducing electrode) 300 .

In other words, the membrane-electrode assembly according to an embodiment of the present invention has an anode (anode, anode, 200) and a cathode (cathode, a cathode, 300) positioned opposite to each other with the composite electrolyte membrane 100 interposed therebetween. to provide At this time, the anode 200 includes an anode gas diffusion layer 3, an anode catalyst layer 2, and an anode electrode substrate 1, and the cathode 300 is a cathode gas diffusion layer 4, a cathode catalyst layer 5 and a cathode An electrode substrate 6 may be included.

Specifically, the anode 200 may be formed by sequentially stacking the anode gas diffusion layer 3, the anode catalyst layer 2 and the anode electrode substrate 1, and the anode gas diffusion layer 3 is a composite electrolyte membrane 200. may be bonded to one side of In addition, the cathode 300 may be formed by sequentially stacking the cathode gas diffusion layer 4 , the cathode catalyst layer 5 and the cathode electrode substrate 6 , and the cathode gas diffusion layer 4 is the composite electrolyte membrane 200 . It may be bonded to the other surface.

The membrane-electrode assembly of the present invention may be formed by disposing the anode 200, the composite electrolyte membrane 100, and the cathode 300, respectively, and then fastening them, or may be formed by pressing them at high temperature and high pressure.

The anode gas diffusion layer 3 may be formed by coating a gas diffusion layer forming material on one surface of the composite electrolyte membrane 100 .

The anode gas diffusion layer 3 may be provided to prevent rapid diffusion of fuel injected into the fuel cell and to prevent a decrease in ion conductivity. In addition, the anode gas diffusion layer 3 may control the diffusion rate of fuel through heat treatment or electrochemical treatment. In addition, the anode gas diffusion layer 3 serves as a current conductor between the composite electrolyte membrane 100 and the anode catalyst layer 2 , and serves as a passage for a gas as a reactant and water as a product. Accordingly, the anode gas diffusion layer 3 may have a porous structure having a porosity of 20% to 90% so that the gas can pass therethrough. The thickness of the anode gas diffusion layer 3 may be appropriately adopted as needed, and may be, for example, 100 to 400 μm. When the thickness of the anode gas diffusion layer 3 is 100 μm or less, the electrical contact resistance between the anode catalyst layer 2 and the anode electrode substrate 1 increases, and the structure may become unstable due to compression. In addition, when the thickness of the anode gas diffusion layer 3 exceeds 400 μm, it may be difficult to move the reactant gas.

In addition, the anode gas diffusion layer 3 may be formed to include a carbon-based material and a fluorine-based resin. Carbon-based materials include graphite, carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nanowire, fullerene (C60) And it may include one or more selected from the group consisting of super P, but is not limited thereto. In addition, as the fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), polyvinyl alcohol, cellulose acetate, polyvinylidene fluoride-hexafluoropropylene copolymer, or styrene-butadiene fluoride (SBR) It may include one or more selected from the group consisting of. In addition, the fuel may be a liquid fuel such as formic acid solution, methanol, formaldehyde, or ethanol.

The anode catalyst layer 2 is a layer into which an oxidation catalyst is introduced, and the anode catalyst layer 2 may be formed by coating a catalyst layer forming material on the anode gas diffusion layer 3 .

The catalyst layer forming material may be a metal catalyst or a metal catalyst supported on a carbon-based support. As the metal catalyst, one or more selected from the group consisting of platinum, ruthenium, a platinum-ruthenium alloy, a platinum-osmium alloy, a platinum-palladium alloy, and a platinum-transition metal alloy may be used typically. In addition, as the carbon-based support, graphite (graphite), carbon black, acetylene black, denka black, ketchen black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nano It may include at least one selected from the group consisting of wire, fullerene, and super P.

In addition, the anode catalyst layer 2 may include a conductive support and an ion conductive binder (not shown). In addition, the anode catalyst layer 2 may include a main catalyst attached to a conductive support. The conductive support may be carbon black, and the ion conductive binder may be a Nafion ionomer or a sulfonated polymer. In addition, the main catalyst may be a metal catalyst, for example, may be platinum (Pt). The anode catalyst layer 2 may be formed using an electroplating method, a spray method, a painting method, a doctor blade method, or a transfer method.

The anode electrode substrate 1 may use a conductive substrate selected from the group consisting of carbon paper, carbon cloth, and carbon felt, but is not limited thereto, and any anode electrode material applicable to a polymer electrolyte fuel cell may be used. possible. The anode electrode substrate 1 may be formed on one surface of the anode catalyst layer 2 through a conventional deposition method, and after forming the anode catalyst layer 2 on the anode electrode substrate 1, the anode gas diffusion layer 3 ) may be formed by disposing the anode catalyst layer 2 and the anode electrode substrate 1 in contact thereon.

The cathode gas diffusion layer 4 may be formed by applying a gas diffusion layer forming material to the other surface of the composite electrolyte membrane 100 .

The cathode gas diffusion layer 4 may be provided to prevent rapid diffusion of the gas injected into the cathode 300 and to uniformly disperse the gas injected into the cathode 300 . In addition, the cathode gas diffusion layer 4 serves as a current conductor between the composite electrolyte membrane 100 and the cathode catalyst layer 5 , and serves as a passage for a gas as a reactant and water as a product. Accordingly, the cathode gas diffusion layer 4 may have a porous structure having a porosity of 20% to 90% so that gas can pass therethrough. The thickness of the cathode gas diffusion layer 4 may be appropriately adopted as needed, and may be, for example, 100 to 400 μm. When the thickness of the cathode gas diffusion layer 4 is 100 μm or less, the electrical contact resistance between the cathode catalyst layer 5 and the cathode electrode substrate 6 increases, and the structure may become unstable due to compression. In addition, when the thickness of the cathode gas diffusion layer 4 exceeds 400 μm, it may be difficult to move the reactant gas.

In addition, the cathode gas diffusion layer 4 may be formed to include a carbon-based material and a fluorine-based resin. Carbon-based materials include graphite, carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nanowire, fullerene (C60) And it may include one or more selected from the group consisting of super P, but is not limited thereto. In addition, as the fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), polyvinyl alcohol, cellulose acetate, polyvinylidene fluoride-hexafluoropropylene copolymer, or styrene-butadiene fluoride (SBR) It may include one or more selected from the group consisting of. In addition, the fuel may be a liquid fuel such as formic acid solution, methanol, formaldehyde, or ethanol.

The cathode catalyst layer 5 is a layer into which a reduction catalyst is introduced, and the cathode catalyst layer 5 may be formed by coating a catalyst layer forming material on the cathode gas diffusion layer 4 .

The catalyst layer forming material may be a metal catalyst or a metal catalyst supported on a carbon-based support. As a metal catalyst, one or more selected from the group consisting of platinum, ruthenium, a platinum-ruthenium alloy, a platinum-osmium alloy, a platinum-palladium alloy, and a platinum-transition metal alloy may be used typically. In addition, as the carbon-based support, graphite (graphite), carbon black, acetylene black, denka black, ketchen black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nano It may include at least one selected from the group consisting of wire, fullerene, and super P.

In addition, the cathode catalyst layer 5 may include a conductive support and an ion conductive binder (not shown). In addition, the cathode catalyst layer 5 may include a main catalyst attached to the conductive support. The conductive support may be carbon black, and the ion conductive binder may be a Nafion ionomer or a sulfonated polymer. In addition, the main catalyst may be a metal catalyst, for example, may be platinum (Pt). The cathode catalyst layer 5 may be formed using an electroplating method, a spray method, a painting method, a doctor blade method, or a transfer method.

The cathode electrode substrate 6 may use a conductive substrate selected from the group consisting of carbon paper, carbon cloth, and carbon felt, but is not limited thereto, and any cathode electrode material applicable to a polymer electrolyte fuel cell may be used. possible. The cathode electrode substrate 6 may be formed on one surface of the cathode catalyst layer 5 through a conventional deposition method, and after forming the cathode catalyst layer 5 on the cathode electrode substrate 6, the cathode gas diffusion layer 4 ) on the cathode catalyst layer 5 and the cathode electrode substrate 6 may be formed by disposing in contact.

On the other hand, the polymer electrolyte membrane fuel cell according to an embodiment of the present invention includes at least one electricity generator that generates electrical energy through an oxidation reaction of fuel and a reduction reaction of an oxidizing agent, and supplies the above-described fuel to the electricity generator. It is configured to include a fuel supply unit and an oxidizer air gap for supplying the oxidizer to the electricity generating unit.

The membrane-electrode assembly of the present invention includes one or more, and separators for supplying fuel and an oxidizing agent are disposed at both ends of the membrane-electrode assembly of the present invention to constitute an electricity generating unit. At least one of these electricity generators may be gathered to form a stack.

At this time, since the arrangement form or manufacturing method of the polymer electrolyte membrane fuel cell of the present invention can be formed without limitation as long as it is a form applicable to the polymer electrolyte fuel cell, it can be variously applied with reference to the prior art.

The method for manufacturing a composite electrolyte membrane of the present invention includes first to fourth steps.

First, in the first step of the method for manufacturing a composite electrolyte membrane of the present invention, a first support layer and a second support layer may be prepared, respectively. In this case, a poly tetra fluoro ethylene (PTFE) porous support may be used as the first support layer and the second support layer, and the PTFE porous support that can be used may be the same as the PTFE porous support and the manufacturing method described above.

Next, in the second step of the method for manufacturing a composite electrolyte membrane of the present invention, the first electrolyte layer may be formed on one surface of the first support layer prepared in the first step, and the third electrolyte layer may be formed on one surface of the second support layer prepared in the first step. An electrolyte layer can be formed.

Specifically, in the second step of the method for manufacturing a composite electrolyte membrane of the present invention, a solution containing a perfluorinated sulfonated ionomer is applied to one surface of the first support layer, or one surface of the first support layer is coated with a perfluorinated sulfonated ionomer. After being impregnated in the solution to be dried, the first electrolyte layer may be formed. In addition, one surface of the second support layer is coated with a solution containing a perfluorinated sulfonated ionomer, or one surface of the second support layer is impregnated with a solution containing a perfluorinated sulfonated ionomer, and then dried to form a third electrolyte layer. can be formed.

The drying of the second step may be performed by applying heat of 60° C. to 200° C. for 1 minute to 30 minutes, respectively, or preferably by applying heat of 70° C. to 150° C. for 15 minutes to 25 minutes. At this time, if the drying temperature is less than 60°C, the liquid retention of the solution containing the perfluorinated sulfonated ionomer impregnated in the first support layer and/or the second support layer may be reduced, and if it exceeds 200°C, the electrolyte membrane and/or the adhesion with the electrode may be deteriorated when the membrane-electrode assembly is manufactured.

Next, in the third step of the method for manufacturing the composite electrolyte membrane of the present invention, the second electrolyte layer may be formed on the other surface of the first support layer prepared in the first step.

Specifically, the third step is a process of forming a second electrolyte layer on the other surface of the first support layer on which the first electrolyte layer is formed. The second electrolyte layer may be formed by impregnating the other surface of the first support layer with a solution containing a perfluorinated sulfonated ionomer and then drying it.

Drying in the third step may be performed by applying heat of 60° C. to 200° C. for 1 minute to 30 minutes, or preferably by applying heat of 70° C. to 150° C. for 5 minutes to 15 minutes. At this time, if the drying temperature is less than 60 ℃, the liquid retention of the solution containing the perfluorinated sulfonated ionomer impregnated in the first support layer may be reduced, and if it exceeds 200 ℃, the electrolyte membrane and / or membrane-electrode assembly manufacturing Adhesiveness with the electrode may be deteriorated.

Finally, in the fourth step of the method for manufacturing a composite electrolyte membrane of the present invention, the second electrolyte layer is laminated on the other surface of the second support layer prepared in the first step, and heat-treated to the first electrolyte layer, the first support layer, and the second The composite electrolyte membrane of the present invention in which an electrolyte layer, a second support layer, and a third electrolyte layer are sequentially stacked may be manufactured.

Specifically, the fourth step is a process of stacking and integrating a first support layer having a first electrolyte layer formed on one surface and a second electrolyte layer formed on the other surface and a second support layer having a third electrolyte layer formed on one surface. The first electrolyte layer, the first support layer, the second electrolyte layer, the second support layer, and the third electrolyte layer are sequentially laminated and heat treated to contact the second electrolyte layer and the second support layer formed on the other surface of the first support layer. It is possible to manufacture the composite electrolyte membrane of the present invention laminated with

The heat treatment of the fourth step may be performed at 100° C. to 200° C. for 1 minute to 20 minutes, preferably at 140° C. to 180° C. for 1 minute to 15 minutes, and the heat treatment temperature is less than 100° C. or the heat treatment time is less than 1 minute. On the other hand, the liquid retention of the first electrolyte layer, the second electrolyte layer and/or the third electrolyte layer may be reduced, and when the heat treatment temperature exceeds 200° C., the first, second and third electrolyte layers and the first and second electrolyte layers Adhesiveness (bonding) between the support layers may be reduced.

The volume of the occluded pores in the first support layer and/or the second support layer of the composite electrolyte membrane subjected to the heat treatment of the fourth step may be 85% by volume or more, preferably 90% by volume or more with respect to the total pore volume.

In the above, the present invention has been mainly described with respect to the embodiment, but this is only an example and does not limit the embodiment of the present invention. It can be seen that various modifications and applications not exemplified above are possible without departing from the scope. For example, each component specifically shown in the embodiment of the present invention can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Support Preparation Example 1: Preparation of PTFE porous support

A paste was prepared by mixing and stirring 23 parts by weight of naphtha, a liquid lubricant, to 100 parts by weight of the PTFE fine powder having an average particle diameter of 570 μm to uniformly disperse it.

Next, the paste was aged at 50° C. for 18 hours, and then compressed using a molding jig to prepare a PTFE block.

Next, after putting the PTFE block into the extrusion mold, pressure extrusion was performed under a pressure of ^{about 0.10 Ton/cm 2 .}

Next, it was rolled using a rolling roll to prepare an unbaked tape having an average thickness of 850 µm.

Next, while the unbaked tape was transferred to a conveyor belt at a speed of 3 M/min, heat of 180° C. was applied and dried to remove the lubricant.

Next, uniaxial stretching (lengthwise stretching) was performed on the unbaked tape from which the lubricant was removed at a stretching temperature of 280° C. and a stretching speed of 10 M/min at 6.5 times.

Next, the uniaxially stretched unbaked tape was biaxially stretched 30 times (width direction stretching) under the conditions of a stretching temperature of 250° C. and a stretching speed of 10 M/min to prepare a porous support.

Next, the uniaxially and biaxially stretched porous support was fired by applying a temperature of 420° C. at a rate of 15 M/min on a conveyor belt to prepare a PTFE porous support having an average thickness of 16 μm and an average pore size of 0.114 μm.

The prepared PTFE porous support was cut to 5 cm × 1 cm (MD direction × TD direction), and the dimensions of the cut PTFE porous support were in the MD direction (= longitudinal direction) and TD direction (= width direction) by the following relational expression 1 The rate of change was measured respectively, and the dimensional change rate in the MD direction was measured to be 1% and the dimensional change rate in the TD direction was measured to be 5%.

[Relational Expression 1]

In Relation 1, A represents the initial length of the porous PTFE support, and B represents the length measured after the PTFE porous support was left at a temperature of 80° C. for 20 minutes.

Support Preparation Example 2: Preparation of PTFE porous support

A PTFE porous support was prepared in the same manner as in Support Preparation Example 1. However, unlike Support Preparation Example 1, a PTFE porous support having an average thickness of 16 μm and an average pore size of 0.114 μm was prepared by varying the uniaxial and biaxial stretching ratios. The prepared PTFE porous support was cut to 5 cm × 1 cm (MD direction × TD direction), and the dimensions of the cut PTFE porous support were in the MD direction (= longitudinal direction) and TD direction (= width direction) according to the above relational expression 1 The rate of change was measured, respectively, and the dimensional change rate in the MD direction was measured to be 5% and the dimensional change rate in the TD direction was measured to be 1%.

Support Preparation Example 3: Preparation of PTFE porous support

A PTFE porous support was prepared in the same manner as in Support Preparation Example 1. However, unlike Support Preparation Example 1, a PTFE porous support having an average thickness of 16 μm and an average pore size of 0.114 μm was prepared by varying the uniaxial and biaxial stretching ratios. The prepared PTFE porous support was cut to 5 cm × 1 cm (MD direction × TD direction), and the dimensions of the cut PTFE porous support were in the MD direction (= longitudinal direction) and TD direction (= width direction) according to the above relational expression 1 The rate of change was measured, respectively, and the dimensional change rate in the MD direction was measured to be 10% and the dimensional change rate in the TD direction was measured to be 10%.

Support Preparation Example 4: Preparation of PTFE porous support

A PTFE porous support was prepared in the same manner as in Support Preparation Example 1. However, unlike Support Preparation Example 1, a PTFE porous support having an average thickness of 16 μm and an average pore size of 0.114 μm was prepared by varying the uniaxial and biaxial stretching ratios. The prepared PTFE porous support was cut to 5 cm × 1 cm (MD direction × TD direction), and the dimensions of the cut PTFE porous support were in the MD direction (= longitudinal direction) and TD direction (= width direction) according to the above relational expression 1 The rate of change was measured respectively, and the dimensional change rate in the MD direction was measured to be 5% and the dimensional change rate in the TD direction was measured to be 5%.

Electrolyte solution Preparation Example 1: Preparation of perfluorinated sulfonated ionomer solution

-SO ₃ 1 part by weight of a radical scavenger (CeZnO, metal oxide, Cerium ion) based on 100 parts by weight of a perfluorinated sulfonated ionomer (solvay, aquivion D98-25DS) having an equivalent weight (EW) of 980 A perfluorinated sulfonated ionomer solution was prepared.

Electrolyte solution Preparation Example 2: Preparation of perfluorinated sulfonated ionomer solution

A PTFE porous support was prepared in the same manner as in Electrolyte Solution Preparation Example 1. However, unlike the electrolyte solution Preparation Example 1 _{, a perfluorinated sulfonated ionomer solution having an equivalent of -SO 3} H group of 720 was used to prepare a perfluorinated sulfonated ionomer solution (solvay, aquivion D72-25DS).

Electrolyte solution Preparation Example 3: Preparation of perfluorinated sulfonated ionomer solution

A PTFE porous support was prepared in the same manner as in Electrolyte Solution Preparation Example 1. However, unlike Electrolyte Solution Preparation Example 1, a perfluorinated sulfonated ionomer solution was prepared using a perfluorinated sulfonated ionomer (solvay, aquivion D66-25DS) having an equivalent of _{-SO 3 H group of 660.}

Electrolyte solution Preparation Example 4: Preparation of perfluorinated sulfonated ionomer solution

A PTFE porous support was prepared in the same manner as in Electrolyte Solution Preparation Example 1. However, unlike the electrolyte solution Preparation Example 1 _{, a perfluorinated sulfonated ionomer solution having an equivalent of -SO 3} H group of 1100 (solvay, aquivion D110-25DS) was used to prepare a perfluorinated sulfonated ionomer solution.

Example 1: Preparation of composite electrolyte membrane

(1) The PTFE porous support prepared in Support Preparation Example 1 was prepared as a first support layer, and the PTFE porous support prepared in Support Preparation Example 2 was prepared as a second support layer.

(2) Fixing the first support layer to a glass substrate, and impregnating one surface of the first support layer with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1 using an applicator, followed by vacuum at 80°C A first electrolyte layer having an average thickness of 23.5 μm was formed on one surface of the first support layer by drying in an oven for 20 minutes.

(3) The second support layer is fixed to a glass substrate, and one side of the second support layer is impregnated with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1 using an applicator, followed by vacuum at 80° C. Drying was performed in an oven for 20 minutes to form a third electrolyte layer having an average thickness of 23.5 μm on one surface of the second support layer.

(4) After impregnating the other surface of the first support layer on which the first electrolyte layer is formed on one surface with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 2, drying in a vacuum oven at 80° C. for 20 minutes to perform the first A second electrolyte layer having an average thickness of 23 μm was formed on the other surface of the support layer.

(5) A second support layer having a third electrolyte layer formed on one surface is laminated on the other surface of the prepared second electrolyte layer, and heat-treated at 160° C. for 10 minutes to form a first electrolyte layer and a first support layer as shown in FIG. 1 (= Due to manufacturing shrinkage, the average thickness is reduced to 5 µm), the second electrolyte layer, the second support layer (= thinned to an average thickness of 5 µm due to manufacturing shrinkage), and the third electrolyte layer are sequentially stacked with an average thickness of 80 A composite electrolyte membrane having a thickness of μm was prepared.

Example 2: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, a composite electrolyte membrane was finally prepared by using the PTFE porous support prepared in Support Preparation Example 1 as the second support layer.

Example 3: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, a composite electrolyte membrane was finally prepared by using the PTFE porous support prepared in Support Preparation Example 2 as the first support layer.

Example 4: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, using the PTFE porous support prepared in Support Preparation Example 3 as the first support layer, and using the PTFE porous support prepared in Support Preparation Example 3 as the second support layer, finally the composite electrolyte membrane prepared.

Example 5: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, using the PTFE porous support prepared in Support Preparation Example 4 as the first support layer, and using the PTFE porous support prepared in Support Preparation Example 4 as the second support layer, finally the composite electrolyte membrane prepared.

Example 6: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the formation of the second electrolyte layer was formed using the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1, not the perfluorine-based sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 2. , and finally a composite electrolyte membrane was prepared.

Example 7: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the formation of the first electrolyte layer and the third electrolyte layer was performed by using the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 2 instead of the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1. was used, and finally a composite electrolyte membrane was prepared.

Example 8: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the formation of the second electrolyte layer was formed using the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 3 instead of the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 2. , and finally a composite electrolyte membrane was prepared.

Example 9: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the formation of the second electrolyte layer was formed using the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 4, not the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 2, , and finally a composite electrolyte membrane was prepared.

Example 10: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the thickness of the first electrolyte layer was 25 μm, the thickness of the second electrolyte layer was 20 μm, and the thickness of the third electrolyte layer was 25 μm, and a composite electrolyte membrane was finally manufactured.

Example 11: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the thickness of the first electrolyte layer was 27.5 μm, the thickness of the second electrolyte layer was 15 μm, and the thickness of the third electrolyte layer was 27.5 μm, and a composite electrolyte membrane was finally manufactured.

Example 12: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the thickness of the first electrolyte layer was 22 μm, the thickness of the second electrolyte layer was 26 μm, and the thickness of the third electrolyte layer was 22 μm, and a composite electrolyte membrane was finally manufactured.

Example 13: Preparation of composite electrolyte membrane

A composite electrolyte membrane was prepared in the same manner as in Example 1. However, unlike Example 1, the thickness of the first electrolyte layer was 19.5 μm, the thickness of the second electrolyte layer was 31 μm, and the thickness of the third electrolyte layer was 19.5 μm, and a composite electrolyte membrane was finally manufactured.

Comparative Example 1: Preparation of composite electrolyte membrane

(1) Support The PTFE porous support prepared in Preparation Example 1 was prepared as a first support layer.

(2) The first support layer is fixed to a glass substrate, and one surface of the first support layer is impregnated with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1 using an applicator, followed by vacuum at 80° C. A first electrolyte layer having an average thickness of 23.5 μm was formed on one surface of the first support layer by drying in an oven for 20 minutes.

(3) After impregnating the other surface of the first support layer on which the first electrolyte layer is formed on one surface with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1, drying in a vacuum oven at 80° C. for 20 minutes to perform the first A third electrolyte layer having an average thickness of 23.5 μm was formed on the other surface of the support layer.

(4) The first electrolyte layer and the first support layer having a first electrolyte layer on one surface and a third electrolyte layer on the other surface are heat-treated at 160° C. for 10 minutes for 10 minutes to form the first electrolyte layer and the first support layer (= average thickness of 5 μm due to manufacturing shrinkage) A composite electrolyte membrane having an average thickness of 52 μm in which the third electrolyte layer was sequentially stacked was prepared.

Comparative Example 2: Preparation of composite electrolyte membrane

(1) Support The PTFE porous support prepared in Preparation Example 2 was prepared as a second support layer.

(2) The second support layer is fixed to a glass substrate, and one surface of the second support layer is impregnated with the perfluorinated sulfonated ionomer solution prepared in Electrolyte Solution Preparation Example 1 using an applicator, followed by a vacuum at 80° C. A first electrolyte layer having an average thickness of 23.5 μm was formed on one surface of the first support layer by drying in an oven for 20 minutes.

(3) After impregnating the other surface of the second support layer on which the first electrolyte layer is formed in the electrolyte solution Preparation Example 1 in the perfluorinated sulfonated ionomer solution, drying in a vacuum oven at 80° C. for 20 minutes to perform the second A third electrolyte layer having an average thickness of 23.5 μm was formed on the other surface of the support layer.

(4) The first electrolyte layer and the second support layer were heat treated at 160° C. for 10 minutes for a second support layer having a first electrolyte layer on one surface and a third electrolyte layer on the other surface (= average thickness of 5 μm due to manufacturing shrinkage) A composite electrolyte membrane having an average thickness of 52 μm in which the third electrolyte layer was sequentially stacked was prepared.

Experimental Example 1: Durability measurement experiment of composite electrolyte membrane (= Fenton test)

A test piece of each of the composite electrolyte membranes prepared in Examples 1 to 13 and Comparative Examples 1 to 2 was prepared in a size of 5 cm × 5 cm (width × length), and the mass was measured after drying in an oven at 80° C. for 5 hours or more. The prepared specimen is immersed in 200 g of a solution prepared by adding ^{3 ppm Fe 2+} to 2% hydrogen peroxide, and then left at 80° C. for 120 hours. The fluoride ion concentration eluted from the test piece was measured using a fluorine ion selective electrode, and the results are shown in Tables 1 to 4 below. In the Fenton test, the lower the measured value, the lower the elution of fluoride ions, that is, the superior durability of the electrolyte membrane.

Experimental Example 2: Measurement of dimensional stability of composite electrolyte membrane

Each of the composite electrolyte membranes prepared in Examples 1 to 13 and Comparative Examples 1 to 2 was cut to 5 cm × 1 cm (MD direction × TD direction), and each of the cut composite electrolyte membranes was cut in the MD direction ( = longitudinal direction) and TD direction (= width direction) were measured respectively, and the results are shown in Tables 1 to 4 below.

[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.

In the dimensional change rate experiment, the lower the measured value, the higher the dimensional stability, that is, the better the mechanical properties of the electrolyte membrane.

Experimental Example 3: Oxygen permeability measurement experiment of composite electrolyte membrane (GTR; cm ³ /m ² ·24h·0.1MPa)

Each of the composite electrolyte membranes prepared in Examples 1 to 13 and Comparative Examples 1 to 2 was cut to φ 97 mm using a sample cutter, and each of the cut composite electrolyte membranes was loaded into a measurement chamber and vacuum treated for 5 hours, followed by ASTM D The oxygen permeability (GTR ; cm ³ /m ² · 24h · 0.1MPa) of the composite electrolyte membrane was measured according to the 1434 regulations, and the results are shown in Tables 1 to 4 below.

Experimental Example 4: Hydrogen permeability measurement experiment of composite electrolyte membrane (ppm)

Each of the composite electrolyte membranes prepared in Examples 1 to 13 and Comparative Examples 1 to 2 was cut to 8 cm × 8 cm (MD direction × TD direction), and the membrane as shown in FIG. 2 including each of the cut composite electrolyte membranes- An electrode assembly was prepared. After that, a single cell including a membrane-electrode assembly as shown in FIG. 2 was prepared, and the hydrogen permeability (ppm) of the single cell was measured using Mass (HIDEN, QGA) equipment at a temperature of 90° C. and RH of 30%. , the results are shown in Tables 1 to 4 below.

Experimental Example 5: Performance measurement experiment of composite electrolyte membrane

Each of the composite electrolyte membranes prepared in Examples 1 to 13 and Comparative Examples 1 to 2 was cut to 8 cm × 8 cm (MD direction × TD direction), and the membrane as shown in FIG. 2 including each of the cut composite electrolyte membranes- An electrode assembly was prepared. Thereafter, the performance was calculated by measuring the voltage (V) measured at a current of 1A under the conditions of a temperature of 65° C. and a RH of 100%, and the results are shown in Tables 1 to 4 below.

As shown in Table 1, it can be seen that the composite electrolyte membrane prepared in Example 1 has excellent durability and dimensional stability, as well as _{low gas permeability of oxygen (O 2} ), hydrogen (H ₂ ), etc., and excellent performance. there was.

As shown in Table 2, it can be seen that the composite electrolyte membrane prepared in Example 1 has excellent durability and dimensional stability, as well as _{low gas permeability of oxygen (O 2} ) and hydrogen (H ₂ ), and excellent performance. there was.

As shown in Table 3, it can be seen that the composite electrolyte membrane prepared in Example 1 has excellent durability and dimensional stability, as well as _{low gas permeability such as oxygen (O 2} ) and hydrogen (H ₂ ), and excellent performance. there was.

As shown in Table 4, it can be seen that the composite electrolyte membrane prepared in Example 1 has excellent durability and dimensional stability, as well as _{low gas permeability of oxygen (O 2} ) and hydrogen (H ₂ ), and excellent performance. there was.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

1: Anode electrode substrate
2: anode catalyst layer
3: anode gas diffusion layer
4: cathode gas diffusion layer
5: Cathode catalyst layer
6: cathode electrode substrate
11: first support layer
12: second support layer
13: third support layer
14: fourth support layer
21: first electrolyte layer
22: second electrolyte layer
23: third electrolyte layer
24: fourth electrolyte layer
25: fifth electrolyte layer
100: composite electrolyte membrane
200: anode
300: cathode

Claims (10)

A composite electrolyte membrane in which a first electrolyte layer, a first support layer, a second electrolyte layer, a second support layer, and a third electrolyte layer are sequentially stacked,
Each of the first support layer and the second support layer comprises a PTFE porous support,
The PTFE porous support of the first support layer has a dimensional change rate in the MD direction of 3% or less and a dimensional change rate in the TD direction of 10% or less, measured by the following Relational Equation 1,
The PTFE porous support of the second support layer has a dimensional change rate in the MD direction of 10% or less and a dimensional change rate in the TD direction of 3% or less, measured by the following Relational Equation 1,
The composite electrolyte membrane has a dimensional change rate in the MD direction of 10% or less and a dimensional change rate in the TD direction of 10% or less as measured by the following relational formula (2).
[Relational Expression 1]

In Relation 1, A represents the initial length of the PTFE porous support, B represents the length measured after the PTFE porous support was left at a temperature of 80° C. for 20 minutes,
[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.
According to claim 1,
The composite electrolyte membrane has a dimensional change rate in the MD direction of 0 to 3% and a dimensional change rate in the TD direction of 0 to 3% as measured by Relational Equation 2 above.
delete According to claim 1,
The PTFE porous support of the first support layer has a dimensional change rate in the MD direction of 0.5 to 2.5%, and a dimensional change rate in the TD direction of 3.5% to 7.5%, measured by Equation 1 above,
The PTFE porous support of the second support layer has a dimensional change rate in the MD direction of 3.5 to 7.5%, and a dimensional change rate in the TD direction of 0.5% to 2.5%, as measured by Equation 1 above.
3. The method of claim 2,
The composite electrolyte membrane is a composite electrolyte membrane, characterized in that it is for PEMFC (Polymer Electrolyte Membrane Fuel Cell) or for water electrolysis.
According to claim 1,
The composite electrolyte membrane may include a third support layer formed on one surface of the third electrolyte layer; and a fourth electrolyte layer formed on one surface of the third support layer; A composite electrolyte membrane further comprising a.
According to claim 1,
Each of the first electrolyte layer and the third electrolyte layer has an _{equivalent weight of -SO 3} H group (EW: equivalent weight) of 700 to 1200,
The second electrolyte layer is _{a composite electrolyte membrane, characterized in that the equivalent weight of the SO 3} H group (EW: equivalent weight) is 900 or less.
According to claim 1,
Each of the first electrolyte layer, the second electrolyte layer, and the third electrolyte layer comprises a perfluorinated sulfonated ionomer.
A first step of preparing each of the first support layer and the second support layer;
a second step of forming a first electrolyte layer on one surface of the first support layer and forming a third electrolyte layer on one surface of the second support layer;
a third step of forming a second electrolyte layer on the other surface of the first support layer; and
A composite electrolyte membrane in which the second electrolyte layer is laminated on the other surface of the second support layer and heat treated to sequentially stack the first electrolyte layer, the first support layer, the second electrolyte layer, the second support layer, and the third electrolyte layer a fourth step of manufacturing; includes,
Each of the first support layer and the second support layer comprises a PTFE porous support,
The PTFE porous support of the first support layer has a dimensional change rate in the MD direction of 3% or less and a dimensional change rate in the TD direction of 10% or less, measured by the following Relational Equation 1,
The PTFE porous support of the second support layer has a dimensional change rate in the MD direction of 10% or less and a dimensional change rate in the TD direction of 3% or less, measured by the following Relational Equation 1,
The method of manufacturing a composite electrolyte membrane, characterized in that the composite electrolyte membrane has a dimensional change rate in the MD direction of 10% or less and a dimensional change rate in the TD direction of 10% or less, as measured by the following relational equation (2).
[Relational Expression 1]

In Relation 1, A represents the initial length of the PTFE porous support, B represents the length measured after the PTFE porous support was left at a temperature of 80° C. for 20 minutes,
[Relational Expression 2]

In Relation 2, A represents the initial length of the composite electrolyte membrane, and B represents the length measured after leaving the composite electrolyte membrane at a temperature of 80° C. for 20 minutes.
anode (oxidation electrode); The composite electrolyte membrane of claim 1; and a cathode (reducing electrode); A membrane-electrode assembly comprising a.

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