KR20230139111A - Manufacturing method for membrane electrode assembly and membrane electrode assembly manufactured using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a membrane electrode assembly and a membrane electrode assembly produced thereby. In one embodiment, the method for manufacturing a membrane electrode assembly includes forming a first ionomer layer and a second ionomer layer on the surfaces of the first laminate and the second laminate, respectively; Preheating the surfaces on which the first ionomer layer and the second ionomer layer are applied to 80°C or higher, respectively; and laminating the first ionomer layer and the second ionomer layer to form an electrolyte layer, wherein the first and second laminates are stacked with a gas diffusion layer and a catalyst layer, respectively, and the first laminate and the second laminate are stacked with a gas diffusion layer and a catalyst layer, respectively. The ionomer layer and the second ionomer layer each contact the catalyst layer.

Description

Membrane electrode assembly manufacturing method and membrane electrode assembly manufactured thereby {MANUFACTURING METHOD FOR MEMBRANE ELECTRODE ASSEMBLY AND MEMBRANE ELECTRODE ASSEMBLY MANUFACTURED USING THE SAME}

The present invention relates to a method for manufacturing a membrane electrode assembly and a membrane electrode assembly produced thereby.

Currently, the problem of greenhouse gases such as carbon dioxide and rising global temperature is a serious problem when using fossil energy, and research on technologies to replace this is being actively researched. Among these, fuel cells and water electrolysis devices generate electricity by reacting hydrogen and oxygen through an electrochemical reaction, and are attracting attention as representative new energy technologies due to their excellent energy efficiency.

A fuel cell is a device that supplies reaction gases (fuel gas and oxidizer gas) to a pair of catalyst electrodes placed with an electrolyte membrane in between, generates an electrochemical reaction, and directly converts the chemical energy of the fuel into electrical energy. . Unlike a fuel cell, a water electrolyzer is a device that electrochemically decomposes water to generate hydrogen and oxygen.

A membrane electrode assembly (MEA) is a member of a fuel cell and is formed by stacking catalyst layers on both sides of a polymer ion-conducting electrolyte membrane. At this time, a gas diffusion layer (GDL) is further formed on one side of the catalyst layer. The polymer ion conductive electrolyte membrane (or electrolyte membrane) is manufactured using an ionomer having ion conductivity, and the ionomer is mainly a perfluorinated sulfonated polymer electrolyte membrane such as Nafion.

A conventional process for continuously manufacturing a membrane electrode assembly involves applying and drying a catalyst slurry on the surface of a substrate layer such as a gas diffusion layer to form a catalyst layer, and forming an electrolyte membrane on the surface of the catalyst layer by hot pressing (catalyst coated substrate). ). Another process includes a CCM process (catalyst coated membrane) in which a catalyst layer is formed by applying and drying a catalyst slurry on both sides of an electrolyte membrane, and a base layer, such as a gas diffusion layer, is hot-pressed and formed on the surface of the catalyst layer.

The CCM process can minimize the interface resistance between the catalyst layer and the electrolyte membrane by forming an electrode layer on the electrolyte membrane. However, deformation of the electrolyte membrane occurs during the manufacturing process, and a protective film is required for each manufacturing process, so variable control is essential and the production speed is relatively high. There is a low problem. On the other hand, the CCS process has a higher interface resistance compared to the CCM process, which reduces performance, but has the advantage of relatively superior productivity due to the simple manufacturing process.

However, the conventional CCM process and CCS process use heat and pressure together to damage the polymer electrolyte membrane during hot press molding or penetrate too deeply into the catalyst layer, which increases the resistance of the interface between the electrolyte membrane and the catalyst, reducing the performance of the fuel cell. There was a problem with this deterioration.

Background technology related to the present invention is disclosed in Republic of Korea Patent Publication No. 2016-0071800 (published on June 22, 2016, title of the invention: Manufacturing method of highly durable electrode membrane assembly for fuel cells).

One object of the present invention is to provide a method for manufacturing a membrane electrode assembly having excellent durability and ionic conductivity.

Another object of the present invention is to provide a method for manufacturing a membrane electrode assembly that minimizes penetration of the electrolyte membrane into the catalyst layer and minimizes the increase in resistance at the interface between the catalyst and the electrolyte membrane.

Another object of the present invention is to provide a method for manufacturing a membrane electrode assembly with excellent homogeneity when manufacturing an electrolyte membrane.

Another object of the present invention is to provide a method for manufacturing a membrane electrode assembly that enables a continuous process and has excellent productivity and economic efficiency.

Another object of the present invention is to provide a membrane electrode assembly manufactured by the above membrane electrode assembly manufacturing method.

One aspect of the present invention relates to a method for manufacturing a membrane electrode assembly. In one embodiment, the method for manufacturing a membrane electrode assembly includes forming a first ionomer layer and a second ionomer layer on the surfaces of the first laminate and the second laminate, respectively; Preheating the surfaces on which the first ionomer layer and the second ionomer layer are applied to 80°C or higher, respectively; and laminating the first ionomer layer and the second ionomer layer to form an electrolyte layer, wherein the first and second laminates are stacked with a gas diffusion layer and a catalyst layer, respectively, and the first laminate and the second laminate are stacked with a gas diffusion layer and a catalyst layer, respectively. The ionomer layer and the second ionomer layer each contact the catalyst layer.

In one embodiment, the first ionomer layer and the second ionomer layer are formed by applying a first ionomer solution and a second ionomer solution to the catalyst layer surfaces of the first and second laminates, respectively, and the first ionomer layer The solution and the second ionomer solution may each include a first ionomer and a second ionomer dispersed in a solvent.

In one embodiment, the application may be performed using a slot die, ultrasonic spray, micro gravure, etc.

In one embodiment, the first ionomer solution and the second ionomer solution may each have a viscosity of 4000 cP (based on 25°C) or less.

In one embodiment, the first ionomer and the second ionomer may each include one or more of a fluorine-based ionomer and a hydrocarbon-based ionomer.

In one embodiment, the gas diffusion layer may include one or more of carbon paper, carbon nonwoven fabric, and carbon cloth.

In one embodiment, the catalyst layer includes an active metal supported on a support, and the support includes one or more of acetylene black, carbon black, porous carbon, carbon nanoparticles, carbon nanotubes, carbon nanofibers, and graphite, and the active metal The metal may include one or more of platinum (Pt), palladium (Pd), gold (Au), and ruthenium (Ru).

In one embodiment, the preheating may be performed at 80 to 110°C.

In one embodiment, the lamination may be performed at a temperature of 80 to 130° C. and a pressure of 50 kgf/cm ² or less.

Another aspect of the present invention relates to a membrane electrode assembly manufactured by the above membrane electrode assembly manufacturing method. In one embodiment, the membrane electrode assembly includes an electrolyte membrane; A pair of catalyst layers formed on both sides of the electrolyte membrane; and a gas diffusion layer formed on each side of the pair of catalyst layers, and may have a thickness of 10 to 50 μm.

In one embodiment, the electrolyte membrane includes at least one of a fluorine-based ionomer and a hydrocarbon-based ionomer, and the catalyst layer includes an active metal supported on a support, wherein the support includes acetylene black, carbon black, porous carbon, carbon nanoparticles, and carbon nano. It includes one or more of tubes, carbon nanofibers, and graphite, and the active metal may include one or more of platinum (Pt), palladium (Pd), gold (Au), and ruthenium (Ru).

In one embodiment, the gas diffusion layer may include one or more of carbon paper, carbon nonwoven fabric, and carbon cloth.

When applying the membrane electrode assembly manufacturing method of the present invention, durability and ionic conductivity are excellent, penetration of the electrolyte membrane into the catalyst layer is minimized, the increase in resistance between the catalyst and electrolyte membrane interface is minimized, electrolyte membrane homogeneity is excellent, and continuous process is possible. It is possible, and productivity and economic efficiency can be excellent.

1 is a schematic diagram showing a method for manufacturing a membrane electrode assembly according to an embodiment of the present invention.
Figure 2 shows a membrane electrode assembly according to one embodiment of the present invention.

In describing the present invention, if it is determined that a detailed description of related known technology or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

In addition, the terms described below are terms defined in consideration of the functions in the present invention, and may vary depending on the intention or custom of the user or operator, so the definitions should be made based on the content throughout the specification explaining the present invention.

Membrane electrode assembly manufacturing method

One aspect of the present invention relates to a method for manufacturing a membrane electrode assembly. 1 is a schematic diagram showing a method for manufacturing a membrane electrode assembly according to an embodiment of the present invention. Referring to FIG. 1, the method for manufacturing a membrane electrode assembly includes (S10) forming an ionomer layer; (S20) Preheating step; and (S30) lamination step.

More specifically, the method for manufacturing a membrane electrode assembly includes (S10) preparing a first and second laminates in which a gas diffusion layer and a catalyst layer are sequentially formed; (S10) forming a first ionomer layer and a second ionomer layer on the surfaces of the first and second laminates, respectively; (S20) preheating the surfaces on which the first ionomer layer and the second ionomer layer are applied to 80°C or higher, respectively; and (S30) laminating the first ionomer layer and the second ionomer layer to form an electrolyte layer, wherein the first and second laminates are stacked with a gas diffusion layer and a catalyst layer, respectively, The first ionomer layer and the second ionomer layer each contact the catalyst layer.

Hereinafter, the method for manufacturing the membrane electrode assembly will be described step by step in detail.

(S10) Ionomer layer formation step

The above step is a step of forming a first ionomer layer and a second ionomer layer on the surfaces of the catalyst layers of the first and second laminates, respectively.

Referring to FIG. 1, the first laminate 101 includes a first gas diffusion layer 111 and a first catalyst layer 121 formed sequentially, and the second laminate 102 includes a second gas diffusion layer 112. and the second catalyst layer 122 may be formed sequentially.

The gas diffusion layer may be porous with multiple pores. Hydrogen and oxygen can be transmitted through the pores, and the generated moisture can be discharged. For example, the gas diffusion layer is porous and may include one or more of carbon paper, carbon non-woven fabric, and carbon cloth. Under the above conditions, gas permeability is excellent and generated moisture can be easily discharged.

In one embodiment, the gas diffusion layer may have a thickness of 50㎛ to 1mm. Under the above conditions, the durability, gas permeability, and moisture discharge properties of the membrane electrode assembly can be excellent.

In one embodiment, the catalyst layer allows gas that has passed through the gas diffusion layer to be transmitted (diffused) and promotes the electrochemical reaction rate.

In one embodiment, the catalyst layer may include an active metal supported on a support. The support may include one or more of acetylene black, carbon black, porous carbon, carbon nanoparticles, carbon nanotubes, carbon nanofibers, and graphite. The active metal may include one or more of platinum (Pt), palladium (Pd), gold (Au), and ruthenium (Ru). When a catalyst under the above support and active metal conditions is included, the durability of the catalyst layer can be excellent, and the power generation efficiency of the fuel cell can be excellent.

In one embodiment, the catalyst layer can be formed by a conventional method. For example, a catalyst containing an active metal supported on the support; dispersing solvent; and a binder; and may be formed by applying a catalyst slurry containing a catalyst slurry to the surface of the gas diffusion layer and drying it. For example, the catalyst slurry may be applied using methods such as spray coating, slot die coating, and blade coating, but is not limited thereto.

In one embodiment, the catalyst layer may have a thickness of 3㎛ to 50㎛. Under the above conditions, the durability of the catalyst layer and the power generation efficiency of the fuel cell can be excellent.

In one embodiment, the dispersing solvent may include one or more of water, alcohol, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), and methylpyrrolidone (DMF). The alcohol may include one or more of monohydric alcohol and glycol (dihydric alcohol). When the dispersing solvent is included, the catalyst slurry may have excellent branching properties and workability. The monohydric alcohol may include one or more of methanol, ethanol, isopropanol, and butanol. The glycol may include one or more of diethylene glycol, propylene glycol, dipropylene glycol, and butylene glycol.

In one embodiment, the binder is one or more of fluorine-based ionomer, hydrocarbon-based ionomer, polyimide, polybenzimidazole, polyetherimide, polyphenylene sulfide, polysulfone, polyethersulfone, polyether ketone, and polyether-ether ketone. may include. When the binder is included, the catalyst layer may have excellent durability and adhesion.

When the binder includes a fluorine-based ionomer and a hydrocarbon-based ionomer, one with a lower weight average molecular weight than the first and second ionomers, which will be described later, can be used.

In one embodiment, the fluorine-based ionomer may include an ion conductive functional group in the side chain and fluorine in the main chain. Additionally, the hydrocarbon-based ionomer may include an ion conductive functional group in the side chain and a hydrocarbon in the main chain.

In one embodiment, the ion conductive functional group may include one or more of a cation conductive functional group and an anion conductive functional group. For example, the cation conductive functional group may include one or more of a hydroxyl group, a sulfonic acid group, a phosphoric acid group, and a carboxyl group. For example, the anion conductive functional group may include one or more of an ammonium group, a phosphonium group, an imidazolium group, a pyridium group, a guanidinium group, and a sulfonium group.

In one embodiment, the fluorine-based ionomer may include one or more of poly(perfluorinated sulfonic acid) and poly(perfluorinated carboxylic acid).

In one embodiment, the hydrocarbon-based ionomer is sulfonated polyphenyleneoxide (sulfonated polypropyleneoxide), sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), and sulfonated polyarylethersulfone (S-PAES). Sulfonated polyetheretherketone (S-PEEK), sulfonated polybenzimidazole (S-PBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S- PS), sulfonated polyphosphazene, and polybenzimidazole.

The ionomer included in the binder may be the same type of ionomer as the first and second ionomers described later.

Referring to FIG. 1, the first laminate 101 and the second laminate 102 may be supplied while being wound around the first supply roll 10 and the second supply roll 12, respectively.

Referring to FIG. 1, the first ionomer layer 201 is formed on the surface of the first catalyst layer 121 of the first laminate 101, and the second ionomer layer 202 is formed on the surface of the first catalyst layer 121 of the first laminate 102. 2 is formed on the surface of the catalyst layer 122.

In one embodiment, the first ionomer layer and the second ionomer layer may be formed by applying a first ionomer solution and a second ionomer solution to the surfaces of the catalyst layer of the first laminate and the catalyst layer of the second laminate, respectively.

Application of the ionomer solution can be performed using a slot die, ultrasonic spray, micro gravure, etc.

Referring to FIG. 1, the first ionomer solution and the second ionomer solution are applied to the surfaces of the first catalyst layer 121 and the second catalyst layer 122 through the first supply part 21 and the second supply part 22. A first ionomer layer 201 and a second ionomer layer 202 may be formed.

In one embodiment, the first ionomer solution and the second ionomer solution may each include a first ionomer and a second ionomer dispersed in a solvent.

In one embodiment, the first ionomer solution and the second ionomer solution may each have a viscosity of 4000 cP (based on 25°C) or less. Under the above conditions, the uniformity of the electrolyte membrane can be excellent, internal ion conductivity and durability can be excellent, and workability and productivity can be excellent. For example, the first ionomer solution and the second ionomer solution may each have a viscosity of 500 to 2000 cP (based on 25°C).

In one embodiment, the first ionomer and the second ionomer may each include one or more of a fluorine-based ionomer and a hydrocarbon-based ionomer.

In one embodiment, the fluorine-based ionomer may include an ion conductive functional group in the side chain and fluorine in the main chain. Additionally, the hydrocarbon-based ionomer may include an ion conductive functional group in the side chain and a hydrocarbon in the main chain.

In one embodiment, the ion conductive functional group may include one or more of a cation conductive functional group and an anion conductive functional group. For example, the cation conductive functional group may include one or more of a hydroxyl group, a sulfonic acid group, a phosphoric acid group, and a carboxyl group. For example, the anion conductive functional group may include one or more of an ammonium group, a phosphonium group, an imidazolium group, a pyridium group, a guanidinium group, and a sulfonium group.

In one embodiment, the fluorine-based ionomer may include one or more of poly(perfluorinated sulfonic acid) and poly(perfluorinated carboxylic acid).

In one embodiment, the hydrocarbon-based ionomer is sulfonated polyphenyleneoxide (sulfonated polypropyleneoxide), sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), and sulfonated polyarylethersulfone (S-PAES). Sulfonated polyetheretherketone (S-PEEK), sulfonated polybenzimidazole (S-PBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S- PS) and sulfonated polyphosphazene.

In one embodiment, the solvent may include one or more of water, alcohol-based solvent, ketone-based solvent, carbonate-based solvent, amide-based solvent, ether-based solvent, sulfoxide-based solvent, ester-based solvent, and hydrocarbon-based solvent. When the solvent is included, the miscibility and dispersibility of the first ionomer and the second ionomer may be excellent.

The alcohol-based solvent may include one or more of methanol, ethanol, isopropanol, and butanol.

The ketone-based solvent may include one or more of acetone, methyl ethyl ketone, and methyl isobutyl ketone.

The sulfoxide-based solvent may include dimethyl sulfoxide (DMSO).

The carbonate-based solvent may include one or more of ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate.

The amide-based solvent may include one or more of N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), and dimethylformamide (DMF).

The ether-based solvent may include one or more of cellosolve, cellosolve acetate, and butyl cellosolve.

The ester-based solvent may include one or more of triacetin, tributyrin, butylphthalylbutyl glycolate, ethylphthalylethylglycolate, methylphthalylethylglycolate, and butylphthalylbutylglycolate.

The hydrocarbon-based solvent may include one or more of toluene and xylene.

For example, the solvent may include water and an alcohol-based solvent.

(S20) Preheating step

This step is a step of preheating the surfaces on which the first ionomer layer and the second ionomer layer are applied to 80°C or higher, respectively. When preheating under the above conditions, the viscosity of the first and second ionomer layers can be easily adjusted to prevent the ionomer from deeply penetrating into the catalyst layer, thereby preventing a decrease in ionic conductivity. When preheating the first ionomer layer and the second ionomer layer to less than 80°C, the ionomer layer may penetrate deeply into the catalyst layer depending on the time taken to move to the subsequent process, and it is not easy to control the viscosity, so the catalyst layer in the lamination process to be described later. As a result, the ionomer layer is deeply penetrated, pores are created inside, the mechanical properties of the electrolyte membrane are reduced, and an excessive amount of ionomer is coated on the catalyst surface, which reduces access to fuel, reducing catalyst efficiency and ion conductivity. You can.

Referring to FIG. 1, the first ionomer layer 201 and the second ionomer layer 202 pass through the first heating furnace 30 and the second heating furnace 32 before lamination, and are heated to a temperature of 80° C. or higher, respectively. It can be preheated. Under the above conditions, the ionomer viscosity can be easily controlled, preventing deep penetration into the catalyst layer, excellent formability, and excellent mechanical properties such as durability of the electrolyte membrane and ion conductivity. For example, it can be preheated to 80~110℃.

(S30) Lamination step

The step is a step of manufacturing a molded body by laminating the first ionomer layer and the second ionomer layer to form an electrolyte layer.

Referring to FIG. 1, the first laminate 101 and the second laminate 102 preheated through the first heating furnace 30 and the second heating furnace 32 are transferred to a compact line. The surface on which the first ionomer layer 201 of the first laminate 101 is formed passes through the compression roller 40 provided in the line, and the second ionomer layer 202 of the second laminate 102 is formed. An electrolyte layer can be formed by laminating cotton.

The molded body includes an electrolyte membrane 200; A first catalyst layer 121 and a second catalyst layer 122 formed on both sides of the electrolyte membrane; and a first gas diffusion layer 111 and a second gas diffusion layer 112 formed on one surface of the first catalyst layer 121 and the second catalyst layer 122.

In one embodiment, the electrolyte membrane may have a thickness of 10 to 50 μm. Within the above thickness range, mechanical properties such as tensile strength and ionic conductivity may be excellent. For example, it may be 10 to 25㎛.

In one embodiment, the lamination may be performed at a temperature of 80°C or higher and a pressure of 50kgf/cm ² or lower. Under the above conditions, moldability is excellent, internal pores are minimized, and the mechanical properties and ionic conductivity of the electrolyte membrane can be excellent.

Referring to FIG. 1, the lamination process is heated by passing through a third heating furnace 34 provided at the rear end of the pressing roller 40, and the third heating furnace may be equipped with a pressing roller (not shown) inside. there is.

When laminated under the above temperature and pressure conditions, the electrolyte layer formed can be prevented from penetrating into the catalyst layer, the occurrence of pores inside the electrolyte membrane can be minimized, and mechanical properties such as durability of the electrolyte membrane and ionic conductivity can be excellent. For example, the lamination may be carried out at a temperature of 80 to 110° C. and a pressure of 50 kgf/cm ² or less.

In one embodiment, after the lamination step, the manufactured molding agent may be transferred to a winding roll 50 and wound.

Membrane electrode assembly manufactured by the membrane electrode assembly manufacturing method

Another aspect of the present invention relates to a membrane electrode assembly manufactured by the above membrane electrode assembly manufacturing method. In one embodiment, the membrane electrode assembly includes an electrolyte membrane; A pair of catalyst layers formed on both sides of the electrolyte membrane; and a gas diffusion layer formed on each side of the pair of catalyst layers.

Figure 2 shows a membrane electrode assembly according to one embodiment of the present invention. Referring to FIG. 2, the membrane electrode assembly 100 includes an electrolyte membrane 200; A first catalyst layer 121 and a second catalyst layer 122 formed on both sides of the electrolyte membrane; and a first gas diffusion layer 111 and a second gas diffusion layer 112 formed on one surface of the first catalyst layer 121 and the second catalyst layer 122. The catalyst and gas diffusion layer may be the same as those described above. The electrolyte membrane may include an ionomer. The same ionomer as described above may be used.

In one embodiment, the electrolyte membrane may have a thickness of 10 to 50 μm. In the above thickness range, the gas crossover phenomenon in which hydrogen and air penetrate the electrolyte membrane can be prevented, while mechanical properties such as tensile strength and ionic conductivity can be excellent. For example, it may be 10 to 25㎛.

In one embodiment, the electrolyte membrane may include an ionomer. It may contain one or more of a fluorine-based ionomer and a hydrocarbon-based ionomer. When the ionomer matrix of the above type is included, the electrolyte membrane can have excellent mechanical properties such as lightness and tensile strength, as well as excellent durability, chemical resistance, and ionic conductivity.

In one embodiment, the fluorine-based ionomer may include an ion conductive functional group in the side chain and fluorine in the main chain. Additionally, the hydrocarbon-based ionomer may include an ion conductive functional group in the side chain and a hydrocarbon in the main chain.

In one embodiment, the ion conductive functional group may include one or more of a cation conductive functional group and an anion conductive functional group. For example, the cation conductive functional group may include one or more of a hydroxyl group, a sulfonic acid group, a phosphoric acid group, and a carboxyl group. For example, the anion conductive functional group may include one or more of an ammonium group, a phosphonium group, an imidazolium group, a pyridium group, a guanidinium group, and a sulfonium group.

In one embodiment, the fluorine-based ionomer may include one or more of poly(perfluorinated sulfonic acid) and poly(perfluorinated carboxylic acid).

In one embodiment, the hydrocarbon-based ionomer is sulfonated polyphenyleneoxide (sulfonated polypropyleneoxide), sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), and sulfonated polyarylethersulfone (S-PAES). Sulfonated polyetheretherketone (S-PEEK), sulfonated polybenzimidazole (S-PBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S- PS) and sulfonated polyphosphazene.

In one embodiment, the catalyst layer may include an active metal supported on a support. The support may include one or more of acetylene black, carbon black, porous carbon, carbon nanoparticles, carbon nanotubes, carbon nanofibers, and graphite. The active metal may include one or more of platinum (Pt), palladium (Pd), gold (Au), and ruthenium (Ru). When a catalyst under the above support and active metal conditions is included, the durability of the catalyst layer can be excellent, and the power generation efficiency of the fuel cell can be excellent.

In one embodiment, the catalyst layer may have a thickness of 3㎛ to 50㎛. Under the above conditions, the durability of the catalyst layer and the power generation efficiency of the fuel cell can be excellent.

The gas diffusion layer may be porous with multiple pores. Hydrogen and oxygen can be transmitted through the pores, and the generated moisture can be discharged. For example, the gas diffusion layer is porous and may include one or more of carbon paper, carbon non-woven fabric, and carbon cloth. Under the above conditions, gas permeability is excellent and generated moisture can be easily discharged.

In one embodiment, the gas diffusion layer may have a thickness of 50㎛ to 1mm. Under the above conditions, the durability, gas permeability, and moisture discharge properties of the membrane electrode assembly can be excellent.

When applying the membrane electrode assembly manufacturing method of the present invention, durability and ionic conductivity are excellent, penetration of the electrolyte membrane into the catalyst layer is minimized, the increase in resistance at the interface between the catalyst and the electrolyte membrane is minimized, the thickness deviation of the electrolyte membrane is minimized, and homogeneity is excellent. , a continuous process is possible and productivity and economic efficiency can be excellent.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and should not be construed as limiting the present invention in any way. Any information not described here can be technically inferred by anyone skilled in the art, so description thereof will be omitted.

Examples and Comparative Examples

Example

(1) Preparation of the first and second laminates: a catalyst containing an active metal (platinum (Pt) 40% by weight) supported on a support (carbon black), a dispersion solvent (water: isopropanol 1:9 weight ratio), and A catalyst slurry containing a binder (poly(perfluorosulfonic acid)) was prepared. (25% of total weight of catalyst). Then, the catalyst slurry was applied and dried on the surface of the first and second gas diffusion layers (porous carbon cloth) with a thickness of 300㎛ to form a catalyst layer with a thickness of 15㎛, thereby preparing the first and second laminates, respectively. Each was wound on the first supply roll (10) and the second supply roll (12).

(2) Preparation of the first ionomer solution and the second ionomer solution: Disperse the ionomer (including poly(perfluorosulfonic acid)) in a solvent (water and ethanol) to produce the first and second ionomer solutions with a viscosity of 500 cP (based on 25°C). were prepared respectively.

(3) Manufacture of membrane electrode assembly: supplying the first laminate 101 and the second laminate 102 wound on the first supply roll 10 and the second supply roll 12, respectively, as shown in FIG. 1. Meanwhile, the first ionomer solution and the second ionomer solution are applied to the surfaces of the first catalyst layer 121 and the second catalyst layer 122 through the first supply part 21 and the second supply part 22, respectively, to form the first ionomer solution. A layer 201 and a second ionomer layer 202 were formed.

Then, the first and second laminates on which the first ionomer layer 201 and the second ionomer layer 202 are formed are passed through the first heating furnace 30 and the second heating furnace 32, respectively, for 80 hours. Preheated to -110°C. Then, the preheated first and second laminates are transferred, and the surface on which the first ionomer layer 201 and the second ionomer layer 202 are formed is pressed by the pressing roller 40 and the third heating furnace 34. ), and a membrane electrode assembly (molded body) was manufactured using a continuous process of forming an electrolyte membrane by laminating at a temperature of 80 to 110 ° C. and a pressure of 50 kgf / cm ² or less. The first catalyst layer and the second catalyst layer were each formed at a density of 0.4 mg/cm ² , and the thickness of the electrolyte membrane was 20 μm. The membrane electrode assembly was formed under the condition of ionomer weight/(ionomer weight+catalyst layer weight) = 25%.

Comparative example

A membrane electrode assembly was manufactured in the same manner as in the above example, except that the first ionomer layer and the second ionomer layer were preheated to 50°C.

Experiment example

(1) Appearance: The interface between the electrolyte membrane and the catalyst layer of the membrane electrode assembly of Examples and Comparative Examples was observed with an electron microscope. The degree of penetration of the electrolyte membrane ionomer component into the catalyst layer was evaluated through the thickness uniformity of the electrolyte membrane, and the results are shown in Table 1 below. (◎: Electrolyte membrane thickness is uniform, △: Electrolyte membrane thickness is partially uneven,

(2) Measurement of ionomer penetration amount (fluorine (F)/platinum (Pt) weight ratio): The ratio of components was measured for the MEA of the manufactured Examples and Comparative Examples. Specifically, after separating the electrolyte membrane, the amount of ionomer penetration into the gas diffusion layer and catalyst layer was measured. Since the ionomer at the interface may not be completely separated, 10% of the surface of the catalyst layer was excluded and evaluated based on the weight of fluorine (F) relative to platinum (Pt) in the catalyst layer (F/Pt) through elemental analysis. (◎: less than 0.35 (35%), ○: 0.35 (35%) or more and less than 0.50 (50%), X: 0.50 (50%) or more).

(3) ECSA evaluation: Electrochemical Surface Area (ECSA) evaluation was conducted on the MEAs of the manufactured Examples and Comparative Examples. Specifically, the ECSA value was obtained through Cyclic Voltammetry (scanning rate of 50mV/s, 0.05~0.9V) by applying it to a fuel cell under the same conditions. (Based on NEDO protocol, 80℃, RH 100%, H ₂ 70 NmL/min, N ₂ 166 NmL/min (nitrogen is blocked before measurement)) (◎: 50 m ² /g or more, ○: 25 m ² /g more than 50 m ² /g, X: less than 25 m ² /g).

Referring to the results in Table 1 above, the embodiment of the present invention enables a continuous process and has excellent productivity, minimizes penetration of the catalyst layer of the electrolyte membrane, and minimizes the increase in resistance at the interface between the catalyst and the electrolyte membrane, thereby improving fuel cell and water electrolysis. It was found to be suitable for use. On the other hand, in the case of the comparative example outside the conditions of the present invention, it was found that the electrolyte membrane penetrated deeply into the catalyst layer and the resistance at the electrolyte membrane interface increased, thereby deteriorating the performance of the membrane electrode assembly. Based on the ionomer under the same conditions, the thickness of the final electrolyte membrane was also It has been degraded.

So far, the present invention has been examined focusing on the embodiments. A person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the equivalent scope should be construed as being included in the present invention.

10: first supply roll 12: second supply roll
21: first supply section 22: second supply section
30: first heating furnace 32: second heating furnace
34: Third heating furnace 40: Compression roller
50: winding roll 100: membrane electrode assembly
101: first laminate 102: second laminate
111: first gas diffusion layer 112: second gas diffusion layer
121: first catalyst layer 122: second catalyst layer
200: electrolyte layer 201: first ionomer layer
202: second ionomer layer

Claims (12)

Forming a first ionomer layer and a second ionomer layer on the surfaces of the first and second laminates, respectively;
Preheating the surfaces on which the first ionomer layer and the second ionomer layer are applied to 80°C or higher, respectively; and
It includes forming an electrolyte layer by laminating the first ionomer layer and the second ionomer layer,
The first and second laminates are each composed of a gas diffusion layer and a catalyst layer,
The first ionomer layer and the second ionomer layer are each in contact with the catalyst layer.
The method of claim 1, wherein the first ionomer layer and the second ionomer layer are:
It is formed by applying a first ionomer solution and a second ionomer solution to the surfaces of the catalyst layers of the first and second laminates, respectively,
The first ionomer solution and the second ionomer solution each include a first ionomer and a second ionomer dispersed in a solvent.
The method of claim 1, wherein the application is performed using one or more of a slot die, micro gravure, and ultrasonic spray.
The method of claim 1, wherein the first ionomer solution and the second ionomer solution each have a viscosity of 4000 cP (based on 25°C) or less.
The method of claim 4, wherein the first ionomer and the second ionomer each include at least one of a fluorine-based ionomer and a hydrocarbon-based ionomer.
The method of claim 1, wherein the gas diffusion layer includes one or more of carbon paper, carbon non-woven fabric, and carbon cloth.
The method of claim 1, wherein the catalyst layer includes an active metal supported on a support,
The support includes one or more of acetylene black, carbon black, porous carbon, carbon nanoparticles, carbon nanotubes, carbon nanofibers, and graphite,
A method of manufacturing a membrane electrode assembly, wherein the active metal includes one or more of platinum (Pt), palladium (Pd), gold (Au), and ruthenium (Ru).
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the preheating is performed at 80 to 110°C.
The method of claim 1, wherein the lamination is performed at a temperature of 80 to 130° C. and a pressure of 50 kgf/cm ² or less.
electrolyte membrane;
A pair of catalyst layers formed on both sides of the electrolyte membrane; and
A gas diffusion layer formed on each side of the pair of catalyst layers,
A membrane electrode assembly, characterized in that the electrolyte membrane has a thickness of 10 to 50㎛.
The method of claim 10, wherein the electrolyte membrane includes at least one of a fluorine-based ionomer and a hydrocarbon-based ionomer,
The catalyst layer includes an active metal supported on a support,
The support includes one or more of acetylene black, carbon black, porous carbon, carbon nanoparticles, carbon nanotubes, carbon nanofibers, and graphite, and the active metals include platinum (Pt), palladium (Pd), gold (Au), and A membrane electrode assembly comprising at least one of ruthenium (Ru).
The membrane electrode assembly of claim 10, wherein the gas diffusion layer includes one or more of carbon paper, carbon nonwoven fabric, and carbon cloth.

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