KR20230143344A - Membrane assembly used in electrochemical hydrogen compressor and manufacturing method thereof - Google Patents

Abstract

A method of manufacturing a membrane assembly for an electrochemical hydrogen compressor according to various embodiments of the present invention for realizing the above-described problems is disclosed. The method may include generating a polymer film based on a polymer mixture, forming a catalyst layer on both sides of the polymer film, and forming a gas diffusion layer on both sides of the catalyst layer.

Description

Membrane assembly used in electrochemical hydrogen compressor and manufacturing method thereof {MEMBRANE ASSEMBLY USED IN ELECTROCHEMICAL HYDROGEN COMPRESSOR AND MANUFACTURING METHOD THEREOF}

The present invention relates to a membrane used in an electrochemical hydrogen compressor, and more specifically, to a membrane assembly with improved mechanical strength and surface area for compression and a method of manufacturing the same.

There is growing interest in using hydrogen energy instead of hydrocarbon-based fossil fuel energy as a way to respond to climate change. Hydrogen can theoretically be converted into electricity with higher energy efficiency than power generation using heat engines, and has the advantage of not emitting harmful substances. Accordingly, much research and development is being conducted on technologies that use hydrogen, such as technologies for producing hydrogen from renewable energy and fuel cells that generate electricity using hydrogen as fuel.

Meanwhile, since hydrogen has a very low energy density per unit volume at room temperature, technology to compress and store hydrogen is needed to utilize hydrogen as an energy carrier. There are two main methods for compressing hydrogen: mechanical and non-mechanical.

The mechanical method is a method of compressing the gaseous state using a mechanical compressor (e.g., a positive displacement compressor). Although it is the most widely used method today, it has various problems (high energy consumption, durability problems of moving parts, contamination of hydrogen by lubricating oil). and noise, etc.), non-mechanical hydrogen compression methods have recently been attracting attention.

Non-mechanical hydrogen compression methods include liquefaction, liquid organic compound conversion, metal hydrogen compound conversion, adsorption on materials with a large specific surface area, and electrochemical compression. Electrochemical hydrogen compression technology has been increasingly used in recent years because it consumes less energy and can compress hydrogen with high purity compared to mechanical technology.

The electrochemical hydrogen compressor is a technology that uses electrical energy to cause an electrochemical reaction of hydrogen and compresses hydrogen due to the fact that charges move in one direction and the airtightness of the membrane (i.e., electrolyte membrane). Specifically, low-pressure hydrogen is injected into the anode of the electrochemical cell, decomposed into hydrogen ions and electrons on the electrode catalyst surface, hydrogen ions move to the cathode through the membrane, and electrons follow the external conductor. It moves to the cathode and generates hydrogen again on the surface of the electrode catalyst. If the applied electrical energy is greater than the energy due to the differential pressure of hydrogen between the cathode and anode, the reaction occurs continuously and hydrogen is compressed.

The membrane is a membrane that only allows hydrogen ions to pass through, so it must have high ionic conductivity and ensure stable performance and lifespan even in various environments. However, there is a risk that the membrane may be deformed by the pressure of hydrogen, and when deformed, the flatness may decrease and hydrogen may not be uniformly delivered to the cathode, which may result in reduced performance and durability.

Accordingly, the industry may require research and development on membrane assemblies to minimize deformation due to pressure through improved mechanical rigidity and improve hydrogen ion transfer performance through a large surface area effect.

Republic of Korea Patent Publication 10-2016-0047515

The problem to be solved by the present invention is to solve the above-mentioned problems and to provide a membrane assembly with improved mechanical strength and surface area for compression.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below.

A method for manufacturing a membrane assembly according to an embodiment of the present invention to solve the above-described problems is disclosed. The method may include generating a polymer film based on a polymer mixture, forming a catalyst layer on both sides of the polymer film, and forming a gas diffusion layer on both sides of the catalyst layer.

In an alternative embodiment, the step of producing the polymer film includes mixing a polymer binder and nanoparticles to produce a nanoparticle-reinforced polymer, mixing the nanoparticle-reinforced polymer in a solvent to produce a polymer solution, It may include adding hollow particles to a polymer solution to produce the polymer mixture in the form of a slurry and generating the polymer film based on the polymer mixture.

In an alternative embodiment, the polymer film includes the hollow particles distributed on the polymer binder, and each of the hollow particles is provided with a plurality of nanoparticles combined, and the hollow particles are, It is a hollow sphere-shaped particle with an empty interior, and the nanoparticle may include at least one of silica, alumina, and zirconium.

In an alternative embodiment, the step of producing the nanoparticle-reinforced polymer may be characterized by mixing the nanoparticles and the polymer binder through a milling process at a cryogenic temperature.

In an alternative embodiment, the step of generating the polymer film includes applying the polymer mixture solution to a mold, curing the mold to which the polymer mixture solution is applied through a preset temperature and pressure to produce a solid polymer specimen. It may include the steps of generating, hydrating the polymer specimen by immersing it in a sulfuric acid solution, removing the solvent contained in the polymer specimen, and separating the polymer specimen from which the solvent has been removed from the mold.

In an alternative embodiment, the step of applying the polymer mixture onto the mold is characterized in that the polymer mixture is uniformly applied onto the mold using a doctor blade-type coater, and the polymer mixture is in contact with the mold. One side of the mold may be surface treated with Teflon coating.

In alternative embodiments, the catalyst layer may comprise porous carbon that supports the catalyst and provides a reaction surface that splits hydrogen into protons through an adsorption mechanism at the metal surface.

In an alternative embodiment, the gas diffusion layer includes at least one of bucky paper, carbon paper, and carbon cloth, and is comprised of PTFE for surface hydrophobization. It may be characterized as being supported through a metal mesh.

In an alternative embodiment, the metal mesh includes a plurality of holes and has a thickness of 10 to 30 μm, and the plurality of holes has a diameter of 10 to 50 μm. You can do this.

A membrane assembly according to another embodiment of the present invention is disclosed. The membrane assembly may include a polymer film, a catalyst layer provided on both sides of the polymer film, and a gas diffusion layer provided on both sides of the catalyst layer.

In an alternative embodiment, the polymer film may include a nanoparticle-reinforced polymer composed of a polymer binder and nanoparticles, and hollow particles dispersed on the nanoparticle-reinforced polymer.

In an alternative embodiment, it includes the hollow particles distributed on the polymer binder, wherein each of the hollow particles is provided with a plurality of the nanoparticles combined, and the hollow particles are hollow with an empty interior. It is a spherical particle, and the nanoparticle may include at least one of zirconium, alumina, and silica.

In an alternative embodiment, the catalyst layer may comprise porous carbon containing a catalyst and providing a reactive surface that splits hydrogen into protons.

In an alternative embodiment, the gas diffusion layer includes at least one of bucky paper, carbon paper, and carbon cloth, and is comprised of PTFE for surface hydrophobization. It may be characterized as being supported through a metal mesh.

In an alternative embodiment, the metal mesh includes a plurality of holes and has a thickness of 10 to 30 μm, and the plurality of holes has a diameter of 10 to 50 μm. You can do this.

In another embodiment of the present invention, a hydrogen compression device comprising the membrane assembly described above is disclosed.

Other specific details of the invention are included in the detailed description and drawings.

According to various embodiments of the present invention, a membrane assembly with improved mechanical strength and surface area for compression can be provided.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Various aspects are described with reference to the drawings below, where like reference numerals are used to collectively refer to like elements. In the examples below, for purposes of explanation, numerous specific details are set forth to provide a comprehensive understanding of one or more aspects. However, it will be clear that such aspect(s) may be practiced without these specific details.
Figure 1 shows an exemplary diagram for explaining the principle of electrochemical hydrogen compression related to an embodiment of the present invention.
2 shows an exemplary flow chart of a method of manufacturing a membrane assembly related to one embodiment of the present invention.
3 shows an exemplary flow chart of a method for producing a polymer film included in a membrane assembly related to one embodiment of the present invention.
Figure 4 shows an exemplary flow chart of a method for producing a polymer film based on a polymer mixture solution related to an embodiment of the present invention.
Figure 5 shows an exemplary cross-sectional view of a membrane assembly related to one embodiment of the present invention.
Figure 6 shows an exemplary cross-sectional view of a polymer film related to one embodiment of the present invention.
7 is an exemplary diagram illustrating a metal mesh related to an embodiment of the present invention.

Various embodiments and/or aspects are disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth to facilitate a general understanding of one or more aspects. However, it will be appreciated by those skilled in the art that this aspect(s) may be practiced without these specific details. The following description and accompanying drawings set forth in detail certain example aspects of one or more aspects. However, these aspects are illustrative and some of the various methods in the principles of the various aspects may be utilized, and the written description is intended to encompass all such aspects and their equivalents. Specifically, as used herein, “embodiment,” “example,” “aspect,” “example,” etc. are not to be construed as indicating that any aspect or design described is better or advantageous over other aspects or designs. Maybe not.

Hereinafter, regardless of the reference numerals, identical or similar components will be assigned the same reference numbers and duplicate descriptions thereof will be omitted. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only intended to facilitate understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings.

Although first, second, etc. are used to describe various elements or components, these elements or components are of course not limited by these terms. These terms are merely used to distinguish one device or component from another device or component. Therefore, it goes without saying that the first element or component mentioned below may also be a second element or component within the technical spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

Additionally, the term “or” is intended to mean an inclusive “or” and not an exclusive “or.” That is, unless otherwise specified or clear from context, “X utilizes A or B” is intended to mean one of the natural implicit substitutions. That is, either X uses A; X uses B; Or, if X uses both A and B, “X uses A or B” can apply to either of these cases. Additionally, the term “and/or” as used herein should be understood to refer to and include all possible combinations of one or more of the related listed items.

Additionally, the terms “comprise” and/or “comprising” mean that the feature and/or element is present, but exclude the presence or addition of one or more other features, elements and/or groups thereof. It should be understood as not doing so. Additionally, unless otherwise specified or the context is clear to indicate a singular form, the singular terms herein and in the claims should generally be construed to mean “one or more.”

When a component is said to be “connected” or “connected” to another component, it is understood that it may be directly connected to or connected to that other component, but that other components may also exist in between. It should be. On the other hand, when a component is said to be “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The suffixes “module” and “part” for the components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in and of themselves.

When an element or layer is referred to as “on” or “on” another element or layer, it means that it is not only directly on top of, but also intervening with, the other element or layer. Includes all intervening cases. On the other hand, when a component is referred to as “directly on” or “directly on,” it indicates that there is no intervening other component or layer.

Spatially relative terms such as “below”, “beneath”, “lower”, “above”, “upper”, etc. are used as a single term as shown in the drawing. It can be used to easily describe a component or its correlation with other components. Spatially relative terms should be understood as terms that include different directions of the element during use or operation in addition to the direction shown in the drawings.

For example, if a component shown in a drawing is turned over, a component described as “below” or “beneath” another component would be placed “above” the other component. You can. Accordingly, the illustrative term “down” may include both downward and upward directions. Components can also be oriented in different directions, so spatially relative terms can be interpreted according to orientation.

The purpose and effects of the present invention, and technical configurations for achieving them, will become clear by referring to the embodiments described in detail below along with the accompanying drawings. In explaining the present invention, if it is determined that a detailed description of a known function 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.

However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are merely provided to ensure that the present invention is complete and to fully inform those skilled in the art of the scope of the disclosure to which the present invention pertains, and that the present invention is only defined by the scope of the claims. . Therefore, the definition should be made based on the contents throughout this specification.

A fuel cell refers to a cell that has the ability to generate direct current by converting the chemical energy of fuel directly into electrical energy. Unlike conventional batteries, it continuously produces electricity by supplying fuel and air from the outside. It has characteristics.

Recently, as fuel cells are very useful in terms of environmental friendliness, a lot of research and development is being conducted to apply fuel cells to various devices. For example, in the case of vehicles using fuel cells, the hydrogen used as fuel is pre-charged in a hydrogen storage tank, and then the hydrogen stored in the hydrogen storage tank is supplied to the fuel cell stack through related pipes to produce electricity, and the fuel cell The electricity produced in the stack drives the motor to drive the vehicle.

Because hydrogen has a very low energy density per unit volume at room temperature, technology to compress and store hydrogen is needed to utilize hydrogen as an energy carrier. In order to increase the energy density of hydrogen, there are methods such as compressing it from gaseous state to high pressure, liquefying it at low temperature, converting it to a liquid organic compound, storing it in metal hydride, or adsorbing it on a material with a large specific surface area.

Meanwhile, the use of electrochemical hydrogen compressors, which consume less energy and are capable of compressing hydrogen with high purity, is increasing recently. The electrochemical hydrogen compressor is a technology that uses electrical energy to cause an electrochemical reaction of hydrogen and compresses hydrogen due to the fact that charges move in one direction and the airtightness of the membrane (i.e., electrolyte membrane). A typical electrochemical hydrogen compressor can perform compression of hydrogen through a membrane 100, anode 200, and cathode 300, as shown in FIG. 1.

Specifically, referring to FIG. 1, low-pressure hydrogen may be injected into the anode 200 of an electrochemical cell. Hydrogen injected through the anode 200 generates hydrogen ions ( ) and electrons ( ) can be decomposed into In this case, hydrogen ions can move to the cathode 300 through the membrane 100, and electrons can move to the cathode 300 through an external conductor connecting the anode 200 and the cathode 300. The hydrogen ions and electrons moved to the cathode 300 produce hydrogen again on the surface of the electrode catalyst of the cathode 300. If the applied electrical energy is greater than the energy due to the hydrogen pressure of the cathode 300, the reaction continues to occur, and hydrogen can be compressed.

The reaction at the anode 200 is as follows.

Additionally, the reaction at the cathode 300 is expressed in the following equation.

The performance of an electrochemical compressor can be represented by the electrical energy used to compress hydrogen. This performance is determined by the voltage of the electrochemical cell, which varies depending on the compression ratio of hydrogen, and can be calculated using the Nernst equation as follows.

Here, the standard electrode potential difference Since both are hydrogen electrodes, it becomes 0V, F is Faraday's constant, R is the ideal gas constant, and T is the electrochemical cell temperature, is the low-pressure hydrogen pressure at the anode, is the high-pressure hydrogen pressure at the cathode. The voltage can be determined according to the compression ratio of the Nernst equation. For example, the Nernst voltage for compression from 1 atmosphere to 100 atmospheres may be 0.059V. The cell voltage calculated using the Nernst equation may be the minimum voltage required to obtain the desired compression ratio, and in actual cells, various voltage losses may be added to determine the cell voltage. Voltage loss occurring in an actual cell includes, for example, voltage loss due to activation polarization of the anode 200 and cathode 300 electrodes, voltage loss due to ohmic resistance, and voltage loss due to mass transfer resistance in the electrodes. It can be included.

In an embodiment, the activation polarization is the voltage loss related to the performance of the catalyst electrode, the ohmic resistance is related to the ionic conductivity of the membrane 100, and the mass transfer resistance may be related to the area where the reactants contact the active surface of the catalyst. . Among these, ohmic resistance and mass transfer resistance due to the membrane are closely related to water distribution inside the cell, so water management inside the cell may be one of the important issues. Accordingly, the membrane must have a high water content, and the catalyst surface of the electrode layer must have good water discharge so that reactants can easily access it. Additionally, in the process where hydrogen ions separated from the anode 200 are transferred to the cathode 300 through the membrane, high pressure may be applied to the membrane, and the membrane may be deformed accordingly. For example, the membrane can be easily deformed by the high pressure of the fuel cell stack. Deformation of the membrane reduces flatness, causing gas flow to be distributed unevenly on the surface of the membrane, and can cause an increase in voltage loss through mass transfer resistance. In addition, deformation of the membrane can cause overall damage to the component.

The purpose of the present invention is to improve system efficiency related to electrochemical hydrogen compressors by minimizing voltage loss related to existing membranes as described above. That is, the present invention can provide a membrane assembly 100 that has improved mechanical rigidity to support high pressure and maximizes hydrogen compression efficiency by maximizing the contact area between the active surface of the catalyst and the reactant. Hereinafter, the method for manufacturing the membrane assembly, the structural characteristics of the membrane assembly, and the resulting effects will be described in detail with reference to FIGS. 2 and 7.

2 shows an exemplary flow chart of a method of manufacturing a membrane assembly related to one embodiment of the present invention. Figure 3 shows an exemplary flow chart of a method for producing a polymer film included in a membrane assembly related to one embodiment of the present invention. Figure 4 shows an exemplary flowchart of a method for producing a polymer film based on a polymer mixture solution related to an embodiment of the present invention. Figure 5 shows an exemplary cross-sectional view of a membrane assembly related to one embodiment of the present invention. Figure 6 shows an exemplary cross-sectional view of a polymer film related to one embodiment of the present invention. 7 is an exemplary diagram illustrating a metal mesh related to an embodiment of the present invention.

The order of the steps included in the membrane assembly manufacturing method shown in FIG. 2 may be changed as needed, and at least one step may be omitted or added. That is, the steps in FIG. 2 are only one embodiment of the present invention, and the scope of the present invention is not limited thereto.

According to one embodiment of the present invention, the membrane assembly manufacturing method may include the step (S110) of generating a polymer film based on the polymer mixture. According to one embodiment, the polymer film 110 may be composed of a polymer binder 112, hollow particles 111, and nanoparticles 111a. As the polymer film 110 includes hollow particles 111 and nanoparticles 111a distributed on the polymer binder 112, it can ensure improved mechanical rigidity. As it is constructed through the improved mechanical rigidity of the polymer film 110, the membrane assembly 100 of the present invention can have a firm support force even against the deformation force caused by the pressure difference occurring during the hydrogen compression process and can improve hydrogen compression efficiency. there is.

According to one embodiment, the polymer film 110 includes hollow particles 111 distributed on a polymer binder 112, and each hollow particle 111 is provided with a plurality of nanoparticles 111a bound to each other. It can be characterized as: Each hollow particle 111 may be distributed at a certain distance on the polymer binder 112.

In an embodiment, the hollow particles 111 included in the polymer film 110 may be hollow sphere-shaped particles with an empty interior. The hollow particles 111 are micro-sized glass hollow particles and may include, for example, hollow silica spheres. For example, the hollow particles 111 may be silica glass bubbles or glass microbubbles. These hollow particles 111 have the advantage of having low density and high thermal insulation performance compared to ceramic particles filled inside. That is, the hollow particles 111 of the present invention may have improved thermal performance and mechanical performance per weight compared to general ceramic particles. For a specific example, the hollow particles 111 can have improved performance in terms of rigidity, strength, vibration damping, insulation characteristics, and energy absorption capacity, and can reduce changes in physical properties due to temperature changes during fuel cell operation. As the polymer film 110 includes hollow particles 111 with improved thermal and mechanical performance, the polymer film 110 can have mechanical rigidity, that is, improved hardness. For example, in the case of a general membrane, it may be composed of a polymer layer in which separate particles (e.g., hollow particles) are not dispersed, but the polymer film 110 included in the membrane assembly 100 of the present invention is shown in Figure 5. As described above, as the plurality of hollow particles 111 are provided in a dispersed state, improved mechanical rigidity can be achieved. This has the advantage of being able to maintain a firm support from applied pressure.

In addition, in the embodiment, the hollow particles 111 can obtain the desired mechanical and thermal performance through the selection of a wide range of manufacturing process variables such as the mixing ratio of the hollow spheres, the size of the hollow spheres, the type of valence inside the hollow spheres, and the wall thickness ratio of the hollow part. There is an advantage in that it can be done.

In one embodiment, each of the hollow particles 111 included in the polymer film 110 may be provided with a plurality of nanoparticles 111a combined therewith. According to one embodiment, the nanoparticles 111a may be nanoparticles related to ceramic materials. Ceramic materials may be made of oxides, carbides, or nitrides made by combining metal elements such as silicon (Si), aluminum (Al), titanium (Ti), and zirconium (Zr) with oxygen, carbon, and nitrogen.

According to one embodiment, the nanoparticles 111a may include at least one of silica, alumina, and zirconium. For example, the ceramic material may include at least one of silica, alumina, and zirconium, which are oxides produced by oxidation of silicon, aluminum, and zirconium, respectively. That is, the nanoparticles 111a of the present invention may refer to ceramic particles having a nanoscale size. Because ceramics do not melt or decompose until high temperatures due to their nature, they have excellent heat resistance and fire resistance. In addition, ceramics are inherently hard because the bonding force between constituent elements is strong, and unlike solid materials, they undergo plastic deformation at high temperatures and do not ductilely break even at high temperatures, and can be made into various shapes, giving them excellent resilience.

In particular, silica or alumina are representative insulators, have high thermal-mechanical stability, and are hydrophilic, which can contribute to improving the water content of polymers. For example, the ohmic resistance and mass transfer resistance of the membrane are closely related to the moisture distribution inside the cell. Specifically, if the moisture inside the cell is not adequate and becomes dry, electron transfer may not occur easily. The membrane that is located between the anode and the cathode and transmits hydrogen ions must have a high water content to minimize voltage loss due to resistance and maximize hydrogen compression efficiency. In the case of nanoparticles 111a made of silica or alumina, they have the advantage of improving the moisture content of the polymer film 110 because they have hydrophilic properties that easily combine with water molecules.

In other words, in the present invention, the polymer film 110 is composed of a plurality of nanoparticles 111a made of a ceramic material, so that it not only has improved mechanical strength, but also improves water content and improves the efficiency of the hydrogen compression system. can contribute to

Additionally, zirconium nanoparticles may be more suitable as a membrane component due to their high ionic conductivity. In general, the higher the membrane ionic conductivity, the improved hydrogen compression efficiency can be. That is, when the plurality of nanoparticles included in the polymer film 110 of the present invention are zirconium-related nanoparticles, the efficiency of the hydrogen compression system can be improved through improvement of ionic conductivity.

In summary, the polymer film 110 has the advantage of having improved mechanical strength as it includes nanoparticles 111a and contributing to improving the efficiency of the hydrogen compression system by improving water content and ionic conductivity.

In addition, the membrane assembly 100 to which the polymer film 110 according to an embodiment of the present invention is applied is in contact with the bipolar plate on both sides, and the bipolar plate contains various by-product gases such as hydrogen gas, oxygen gas, and water vapor on the surface. It includes a plurality of guiding holes that serve as passages for discharging. At this time, the fastening pressure between the biopolar plate and the membrane assembly 100 ranges from 100 to 1000 bar, but because the durability of the polymer film layer in the conventional membrane assembly is weak, a phenomenon in which the membrane assembly is pushed into the guiding hole occurred.

The polymer film 110 according to an embodiment of the present invention further contains hollow particles and nanoparticles, thereby significantly increasing durability compared to the existing one, thereby solving the problem of the membrane assembly 100 being rolled into the guiding hole. In addition, the flatness of the membrane assembly 100 itself is dramatically improved compared to the prior art, thereby making the flow of gas discharged to the bipolar plate more uniform, thereby further increasing hydrogen compression efficiency.

According to one embodiment of the present invention, the membrane assembly manufacturing method may include forming a catalyst layer 120 on both sides of the polymer film 110 (S200). As shown in FIG. 5, the catalyst layer 120 may be provided in contact with the upper and lower surfaces of the polymer film 110, respectively. That is, the catalyst layer 120 may be provided corresponding to each of the anode and cathode directions with respect to the polymer film 110.

In one embodiment, the catalyst layer 120 may provide a space for separation of hydrogen protons. The catalyst layer 120 may be composed of porous carbon containing a catalyst. The catalyst layer 120 can serve as a catalyst for oxidation and reduction reactions. Here, the catalyst is used to promote the hydrogen oxidation reaction and may include, for example, platinum, palladium, gold, silver, rhodium, etc., but is not limited thereto. In an embodiment, as the catalyst layer 120 is provided in a porous shape, the surface area may be increased and reactivity through the catalyst may be improved. In other words, by adsorbing metal on carbon, a relatively expensive catalyst can be distributed over a large surface area, thereby increasing activity.

Meanwhile, since the polymer film 110 according to an embodiment of the present invention has higher durability than a conventional polymer film, the phenomenon of the membrane assembly 100 being pushed into the guide hole in the bipolar plate is prevented. Through this, the peeling phenomenon between the polymer film 110 layer and the catalyst layer 120 is minimized. In the case of a conventional membrane assembly, since the catalyst layer is Pt/C and contains a large amount of carbon powder, there were problems such as the carbon powder penetrating into the polymer film layer and the gas diffusion layer, or the density of the catalyst layer itself was changed.

According to one embodiment of the present invention, the membrane assembly manufacturing method may include forming a gas diffusion layer 130 on both sides of the catalyst layer 120 (S300). As shown in FIG. 5, the gas diffusion layer 130 may be provided in contact with each catalyst layer located on the upper and lower surfaces of the polymer film 110. For example, the gas diffusion layer 130 may be provided in the upper direction of the upper catalyst layer located on the upper surface of the polymer film 110 and in the lower direction of the lower catalyst layer located on the lower surface of the polymer film 110.

In one embodiment, the gas diffusion layer 130 may serve to evenly and widely transfer gas to the catalyst layer 120. The gas diffusion layer 130 may provide a passage through which the reaction gas moves to the catalyst layer 120. Additionally, the gas diffusion layer 130 may provide a passage through which generated moisture escapes to the catalyst layer. The gas diffusion layer 130 is a component that diffuses reactants into the catalyst layer 120, serves as an electrical conductor to transfer generated electrons to the cathode, and acts as a passage to discharge generated water and heat, affecting electrode performance and durability. can affect Therefore, it must have high gas permeability, electrical conductivity, hydrophobicity, and thermal stability.

According to one embodiment, the gas diffusion layer 130 may be provided through a conductive member having gas diffusion properties. The gas diffusion layer 130 may be composed of at least one of bucky paper, carbon paper, and carbon cloth. In an embodiment, the gas diffusion layer 130 may include a hydrophobic polymer PTFT (polytetrafluoroethylene) binder. In a specific embodiment, the gas diffusion layer 130 may be provided by partially containing PTFE polymer in bucky paper. According to an example, as the content of PTFE polymer increases, hydrophobicity increases, which is advantageous for water discharge, but electrical conductivity may decrease and resistance loss may increase. That is, the gas diffusion layer 130 of the present invention includes at least one of bucky paper, carbon paper, and carbon cloth with excellent gas permeability, conductivity, and thermal stability, and is composed of PTFE, a hydrophobic polymer, so that it has high gas permeability, It may have electrical conductivity, thermal stability, and hydrophobicity.

Additionally, the gas diffusion layer 130 may be supported by a metal mesh 140. Specifically, the gas diffusion layer 130 may be provided to surround the catalyst layer 120 in the upper and lower directions with respect to the polymer film 110. In this case, the metal mesh 140 may be provided in contact with one surface (eg, the other surface corresponding to the one surface in contact with the catalyst layer) of the two gas diffusion layers 130. That is, as shown in FIG. 5, the outer surface of the membrane assembly 100 may be supported through the metal mesh 140.

According to one embodiment, the metal mesh 140 is made of a copper alloy and may be provided with a thickness of 10 to 30 μm. The above-described thickness of the metal mesh 140 may be an optimal thickness for supporting the pressure applied to the membrane assembly. As the metal mesh 140 is made of a copper alloy, it can have mechanical strength above a certain level. Copper alloy has the advantage of excellent mechanical properties and corrosion resistance.

In other words, the metal mesh 140 may be provided to have a strength of a certain level or more as it is provided with the above-mentioned thickness, and the polymer film 110, catalyst layer 120, and gas diffusion layer located inside the metal mesh 140 The support capacity of (130) can be improved. In other words, even if pressure is generated during the hydrogen compression process, the overall support capacity of the membrane assembly 100 can be improved due to the high support force through the metal mesh 140 supported on the outermost side.

According to one embodiment, the metal mesh 140 may include a plurality of holes 141, as shown in FIG. 7. The plurality of holes 141 may refer to holes for smoothly passing hydrogen molecules. In one embodiment, the plurality of holes 141 may be provided with a diameter of 10 to 50 μm. In an embodiment, hydrogen gas molecules may pass through the plurality of holes 141 provided in the metal mesh 140 and be transferred to the cathode. That is, the metal mesh 140 can improve the overall support capacity of the membrane assembly 100 in response to pressure without impeding the movement of gas through the plurality of holes 141.

The order of the steps included in the polymer film production method shown in FIG. 3 may be changed as needed, and at least one step may be omitted or added. That is, the steps in FIG. 3 are only one embodiment of the present invention, and the scope of the present invention is not limited thereto.

In an embodiment, the step of generating a polymer film may include mixing the polymer binder 112 and the nanoparticles 111a to generate a nanoparticle-reinforced polymer (S110). The polymer binder 112 may include at least one of perfluorosulfonic acid (PFSA) polymer and polybenzimidazole (PBI) polymer.

According to one embodiment, the nanoparticles 111a may be nanoparticles related to ceramic materials. Ceramic materials may be made of oxides, carbides, or nitrides made by combining metal elements such as silicon (Si), aluminum (Al), titanium (Ti), and zirconium (Zr) with oxygen, carbon, and nitrogen.

According to one embodiment, the nanoparticles 111a may include at least one of silica, alumina, and zirconium. For example, the ceramic material may include at least one of silica, alumina, and zirconium, which are oxides produced by oxidation of silicon, aluminum, and zirconium, respectively. That is, the nanoparticles 111a of the present invention may refer to ceramic particles having a nanoscale size. Because ceramics do not melt or decompose until high temperatures due to their nature, they have excellent heat resistance and fire resistance. In addition, ceramics are inherently hard because the bonding force between constituent elements is strong, and unlike solid materials, they undergo plastic deformation at high temperatures and do not ductilely break even at high temperatures, and can be made into various shapes, giving them excellent resilience.

In particular, silica or alumina are representative insulators, have high thermal-mechanical stability, and are hydrophilic, which can contribute to improving the water content of polymers. For example, the ohmic resistance and mass transfer resistance of the membrane are closely related to the moisture distribution inside the cell. Specifically, if the moisture inside the cell is not adequate and becomes dry, electron transfer may not occur easily. The membrane that is located between the anode and the cathode and transmits hydrogen ions must have a high water content to minimize voltage loss due to resistance and maximize hydrogen compression efficiency. In the case of nanoparticles 111a made of silica or alumina, they have the advantage of improving the moisture content of the polymer film 110 because they have hydrophilic properties that easily combine with water molecules.

In other words, in the present invention, the polymer film 110 is composed of a plurality of nanoparticles 111a made of a ceramic material, so that it not only has improved mechanical strength, but also improves water content and improves the efficiency of the hydrogen compression system. can contribute to

According to an embodiment, the step of generating a nanoparticle-reinforced polymer may be characterized by mixing the nanoparticles 111a and the polymer binder 112 through a milling process at a cryogenic temperature. Milling may refer to a process of uniformly mixing plasticizers, stabilizers, fillers, colorants, etc. with polymer materials such as synthetic resins and rubber through mechanical action using a milling cutter. In one embodiment, the dispersion of the nanoparticles 111a within the polymer binder 112 can be improved through a cryogenic milling process. For example, by mechanically pulverizing the powder in a cryogenic medium, nano-sized particles can be uniformly dispersed on the polymer binder 112 using high shear strain without deformation of the polymer due to heating. For a specific example, ceramic-related nanoparticles 111a may be mixed into the polymer binder 112 composed of PFSA or PBI in the form of pellets in a milling machine, and milling may be performed for 10 minutes.

Additionally, the step of generating a polymer film may include mixing a nanoparticle-reinforced polymer in a solvent to create a polymer solution (S120). Nanoparticle-reinforced polymer in the form of milled powder can be added to the solvent. In an embodiment, the solvent is used to dissolve the nanoparticle-reinforced polymer composed of the polymer binder 112 and the nanoparticles 111a, and may include, for example, ethanol, methanol, propanol, NMP, etc. Depending on the embodiment, a polymer solution may be created by adding a solvent to the nanoparticle-reinforced polymer until fluidity is secured.

Additionally, the step of generating a polymer film may include adding hollow particles to a polymer solution to generate a slurry-type polymer mixture (S130). In an embodiment, the hollow particle 111 may be a hollow sphere-shaped particle with an empty interior. The hollow particles 111 are micro-sized glass hollow particles and may include, for example, hollow silica spheres. For example, the hollow particles 111 may be silica glass bubbles or glass microbubbles. These hollow particles 111 have the advantage of having low density and high thermal insulation performance compared to ceramic particles filled inside. That is, the hollow particles 111 of the present invention may have improved thermal performance and mechanical performance per weight compared to general ceramic particles. For a specific example, the hollow particles 111 may have improved performance in terms of rigidity, strength, vibration damping, thermal insulation characteristics, and energy absorption capacity. As the polymer film 110 includes hollow particles 111 with improved thermal and mechanical performance, the polymer film 110 can have mechanical rigidity, that is, improved hardness. For example, in the case of a general membrane, it may be composed of a polymer layer in which separate particles (e.g., hollow particles) are not dispersed, but the polymer film 110 included in the membrane assembly 100 of the present invention is shown in Figure 5. As described above, as the plurality of hollow particles 111 are provided in a dispersed state, improved mechanical rigidity can be achieved. This has the advantage of being able to maintain a firm support from applied pressure. In addition, in the embodiment, the hollow particles 111 can obtain the desired mechanical and thermal performance through the selection of a wide range of manufacturing process variables such as the mixing ratio of the hollow spheres, the size of the hollow spheres, the type of valence inside the hollow spheres, and the wall thickness ratio of the hollow part. There is an advantage in that it can be done.

According to the embodiment, an impeller-type stirrer may be used to uniformly mix the hollow particles 111 in the polymer solution. In this case, the rotation speed of the impeller type stirrer can be slowed to prevent large bubbles from being mixed. A stirrer can refer to equipment that helps spread, disperse, and stir samples with various viscosities and characteristics under various conditions. In one embodiment, when hollow particles 111 are added to a polymer solution comprising a polymer binder 112, nanoparticles 111a, and a solvent, each hollow particle 111 contains a plurality of nanoparticles 111a. can be tied together.

Additionally, the step of generating a polymer film may include generating a polymer film based on the polymer mixture (S140). Specifically, the polymer mixture can be applied to a flat surface and cured to produce the polymer film 110. The process of producing the polymer film 110 based on the polymer mixture will be described in detail below with reference to FIG. 4.

The order of the steps included in the polymer film production method shown in FIG. 4 may be changed as needed, and at least one step may be omitted or added. That is, the steps in FIG. 4 are only one embodiment of the present invention, and the scope of the present invention is not limited thereto.

According to one embodiment, the step of generating a polymer film may include applying a polymer mixture onto a mold (S141). Here, the polymer mixed solution may mean a mixed solution in which the polymer binder 112, nanoparticles 111a, and hollow particles 111 are dissolved in a solvent. Specifically, the polymer mixture can be uniformly applied onto the mold using a doctor blade-type coater. For example, the doctor blade applies a slurry (a mixture of solids and liquids, i.e., a polymer mixture) onto the mold, and passes a blade (i.e., a blade) designed to maintain a certain distance from the floor upward to create a sheet. It may be the coating method used to create it. That is, the polymer mixture can be placed on the mold and evenly applied on the surface of the mold using a doctor blade-type coater. In this case, one surface of the mold to which the polymer mixture is applied may be surface treated through Teflon coating. The Teflon coating on one side of the mold can facilitate the separation (or separation) of the polymer mixture from the mold.

Additionally, the step of generating the polymer film may include curing the mold to which the polymer mixture solution is applied through a preset temperature and pressure to generate a solid polymer specimen (S142). In a specific example, the mold to which the polymer mixture is applied is placed in a hot press, the temperature is set to 100 to 200°C, and the pressure is maintained at 10 to 50 bar to perform curing of the polymer mixture, thereby producing a polymer specimen. can do. That is, the polymer specimen may be a solid polymer mixture cured at a preset temperature and pressure (i.e., a temperature of 100 to 200° C. and a pressure of 10 to 50 bar).

Additionally, the step of creating a polymer film may include hydrating the polymer specimen by immersing it in a sulfuric acid solution (S143). In an example, a polymer specimen hydrated by a sulfuric acid solution may be washed through deionized water.

Additionally, the step of generating a polymer film may include removing the solvent contained in the polymer specimen (S144). In one embodiment, the solvent contained in the polymer specimen can be removed using a vacuum oven. The solvent may be used for uniform mixing between the polymer binder 112, hollow particles 111, and nanoparticles 111a and then removed. That is, a polymer specimen from which the solvent has been removed may be the polymer film 110 of the present invention.

Additionally, the step of generating a polymer film may include separating the polymer specimen from which the solvent has been removed from the mold (S145). In this case, one surface of the mold in contact with the polymer specimen is surface-treated through Teflon coating, so the polymer specimen can be easily separated (or separated) from the mold.

That is, the polymer film 110 may be provided including a polymer binder 112, hollow particles 111, and nanoparticles 111a, as shown in FIG. 6. In this case, the polymer film 110 includes hollow particles 111 distributed on a polymer binder 112, and each hollow particle 111 is provided with a plurality of nanoparticles 111a bound to each other. can do. Each hollow particle 111 may be distributed at a certain distance on the polymer binder 112. That is, a polymer adsorption layer with a nano to sub-micrometer thickness may be formed on each of the plurality of nanoparticles 111a coupled to each hollow particle 111. This adsorption layer expands the surface area and maximizes mechanical interaction (Van der Waals interaction, anchoring effect) with the polymer, thereby enabling the polymer film 110 to have improved rigidity and a large surface area effect.

As a result, the polymer film 110 has improved mechanical properties as hollow particles 111 with excellent thermal and mechanical performance and nanoparticles 111a with high mechanical strength, moisture content, and ionic conductivity are dispersed on a polymer binder. It can have strength, water content and ionic conductivity.

For example, in a general hydrogen compression process, when hydrogen ions separated from the anode 200 are transferred to the cathode 300 through the membrane, high pressure may be applied to the membrane, and the membrane may be deformed accordingly. For example, the membrane can be easily deformed by the high pressure of the fuel cell stack. Deformation of the membrane reduces flatness, causing gas flow to be distributed unevenly on the surface of the membrane, and can cause an increase in voltage loss through mass transfer resistance. In addition, deformation of the membrane can cause overall damage to the component.

The present invention has the advantage that the membrane assembly 100, which includes the polymer film 110, has improved mechanical strength and contributes to improving the efficiency of the hydrogen compression system by improving water content and ionic conductivity. In particular, it has the advantage of having improved bearing capacity in response to high pressure.

Additionally, since the catalyst layer 120, gas diffusion layer 130, and metal mesh 140 are provided on the outer surface of the polymer film 110, it can contribute to improving the bearing capacity according to pressure. In particular, as the metal mesh 140, which has high mechanical strength, is supported on the outermost side, the overall support capacity of the membrane assembly 100 can be improved.

That is, due to the structural characteristics of the membrane assembly 100 described above, it can have improved support capacity corresponding to the high pressure generated during the hydrogen compression process. In other words, the membrane assembly 100 has improved mechanical rigidity to support high pressure and can maximize hydrogen compression efficiency by maximizing the contact area between the active surface of the catalyst and the reactant.

Above, embodiments of the present invention have been described with reference to the attached drawings, but those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will be able to understand it. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

It is to be understood that the specific order or hierarchy of steps in the processes presented is an example of illustrative approaches. It is to be understood that the specific order or hierarchy of steps in processes may be rearranged within the scope of the present invention, based on design priorities. The appended method claims present elements of the various steps in a sample order but are not meant to be limited to the particular order or hierarchy presented.

100: Membrane assembly 110: Polymer film
111: hollow particle 111a: nanoparticle
112: polymer binder 120: catalyst layer
130: gas diffusion layer 140: metal mesh
141: plurality of holes 200: anode
300: cathode

Claims (13)

Creating a polymer film based on the polymer mixture;
Forming a catalyst layer on both sides of the polymer film; and
Forming a gas diffusion layer on both sides of the catalyst layer;
Including,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to paragraph 1,
The step of producing the polymer film is,
Mixing a polymer binder and nanoparticles to produce a nanoparticle-reinforced polymer;
Mixing the nanoparticle-reinforced polymer with a solvent to produce a polymer solution;
Adding hollow particles to the polymer solution to produce the polymer mixture in the form of a slurry; and
Preparing the polymer film;
Including,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to paragraph 2,
The polymer film is,
It includes the hollow particles distributed on the polymer binder, and each of the hollow particles is provided with a plurality of the nanoparticles bound to each other,
The hollow particles are,
It is a hollow sphere-shaped particle with an empty interior.
The nanoparticles are,
Containing at least one of silica, alumina, and zirconium,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to paragraph 2,
The step of producing the nanoparticle-reinforced polymer is,
Characterized in mixing the nanoparticles and the polymer binder through a milling process at cryogenic temperature,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to paragraph 2,
The step of manufacturing the polymer film is,
Applying the polymer mixture onto a mold;
Curing the mold coated with the polymer mixture at a preset temperature and pressure to produce a solid polymer specimen;
Hydrating the polymer specimen by immersing it in a sulfuric acid solution;
Removing the solvent contained in the polymer specimen; and
separating the polymer specimen from which the solvent has been removed from the mold;
Including,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to clause 5,
The step of applying the polymer mixture onto the mold,
Characterized in uniformly applying the polymer mixture onto the mold using a doctor blade-type coater,
One surface of the mold in contact with the polymer mixture is,
Characterized by surface treatment through Teflon coating,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
According to paragraph 1,
The gas diffusion layer is,
It includes at least one of bucky paper, carbon paper, and carbon cloth, and is characterized in that it is composed of PTFE and is supported through a metal mesh,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
In clause 7,
The metal mesh is,
It includes a plurality of holes and is characterized in that it is provided through a thickness of 10 to 30㎛,
The plurality of holes are,
Characterized in that it is provided through a diameter of 10 to 50㎛,
Method for manufacturing membrane assembly for electrochemical hydrogen compressor.
polymer film;
A catalyst layer provided on both sides of the polymer film; and
A gas diffusion layer provided on both sides of the catalyst layer;
Including,
Membrane assembly for electrochemical hydrogen compressor.
According to clause 9,
The polymer film is,
Nanoparticle-reinforced polymers consisting of polymer binders and nanoparticles; and
Hollow particles dispersed on the nanoparticle-reinforced polymer;
Including,
Membrane assembly for electrochemical hydrogen compressor.
According to clause 10,
It includes the hollow particles distributed on the polymer binder, and each of the hollow particles is provided with a plurality of the nanoparticles bound to each other,
The hollow particles are,
It is a hollow sphere-shaped particle with an empty interior.
The nanoparticles are,
Containing at least one of zirconium, alumina, and silica,
Membrane assembly for electrochemical hydrogen compressor.
According to clause 9,
The gas diffusion layer is,
It includes at least one of bucky paper, carbon paper, and carbon cloth, and is characterized in that it is composed of PTFE and is supported through a metal mesh,
Membrane assembly for electrochemical hydrogen compressor.
According to clause 12,
The metal mesh is,
It includes a plurality of holes and is characterized in that it is provided through a thickness of 10 to 30㎛,
The plurality of holes are,
Characterized in that it is provided through a diameter of 10 to 50㎛,
Membrane assembly for electrochemical hydrogen compressor.

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