Ion exchange membrane and electrochemical system comprising an ion exchange membrane

Abstract

The present invention relates to an ion exchange membrane and an electrochemical system including the same. The ion exchange membrane according to the present invention can maintain high ion conductivity and durability, and has high gas barrier properties, thereby realizing an electrochemical system with excellent efficiency.

Description

Cross-reference to related applications

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2023-0144774, filed with the Korean Intellectual Property Office on October 26, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to an ion exchange membrane and an electrochemical system including the ion exchange membrane. Background Technology

[0003] In recent years, as the problem of climate change caused by global warming has become increasingly serious, researching alternative energy sources to reduce greenhouse gas emissions has become a key focus of attention.

[0004] Among them, polymer electrolyte membrane fuel cells and water electrolysis are pollution-free systems that utilize the energy from the chemical reaction between hydrogen and oxygen. These systems have high output density and energy conversion efficiency, and can be reduced in size, making them suitable for a wide range of applications, such as portable power supplies for mobile communication devices, transportation power supplies for automobiles, and power generation systems for home and military use.

[0005] Separation membranes are crucial components in fuel cells and water electrolysis. These membranes must possess high ionic conductivity, chemical, thermal, mechanical, and electrochemical stability, and effectively prevent the movement of matter between the positive and negative electrodes.

[0006] Water electrolysis is a technology that electrochemically splits water to produce hydrogen and oxygen. In the anion exchange membrane-based water electrolysis (AEMWE) method, a unit cell includes an anion exchange membrane, a negative electrode formed on one side of the anion exchange membrane, and a positive electrode formed on the other side of the anion exchange membrane.

[0007] Multiple cell units are stacked in series to form a water electrolysis stack, which receives an alkaline solution from an electrolyte tank, decomposes water, and generates hydrogen and hydroxide ions at the positive electrode. The hydroxide ions generated here are transferred to the other side via an anion exchange membrane, and an electrochemical reaction is initiated at the negative electrode, in which oxygen is generated from the hydroxide ions.

[0008] In this case, the anion exchange membrane is an intermediate electrolyte membrane, which must have high hydroxide ion conductivity and be impermeable to hydrogen and oxygen produced by water electrolysis.

[0009] When anion exchange membranes are used in the aforementioned electrochemical systems, they can operate under relatively high pH conditions. Therefore, they have the advantage of using low-cost catalysts instead of conventional expensive platinum-based noble metal catalysts, thereby reducing the overall operating cost of the system.

[0010] However, it is necessary to study the anion exchange membranes used in electrochemical systems based on anion exchange membranes, as these membranes have low anion conductivity, high permeability, and low durability. Summary of the Invention

[0011] [Technical Issues] An ion exchange membrane with high anion conductivity, low air permeability, and excellent durability is provided.

[0012] An electrochemical system including the ion exchange membrane is also provided.

[0013] [Technical Solution] According to one aspect of this invention, an ion exchange membrane is provided, comprising: a catalyst layer containing a hydration reaction catalyst, and an ion-conducting insulating layer.

[0014] According to an embodiment, the ion-conducting insulating layer may include a first ion-conducting insulating layer and a second ion-conducting insulating layer.

[0015] According to an embodiment, the ion exchange membrane includes a catalyst layer containing a hydration reaction catalyst; a first ion-conducting insulating layer formed on one surface of the catalyst layer; and a second ion-conducting insulating layer formed on the other surface of the catalyst layer.

[0016] According to the implementation method, the catalyst layer can exist in a form that is isolated from the outside by an ion-conducting insulating layer.

[0017] According to an embodiment, the ion exchange membrane may include a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer.

[0018] According to an embodiment, the ion exchange membrane may also include a strength-enhancing layer.

[0019] According to an embodiment, the strength-enhancing layer may include a porous polymer membrane.

[0020] According to the embodiments, the catalyst layer may comprise a hydrated reaction catalyst and an anionic ionomer.

[0021] According to embodiments, the hydration reaction catalyst may include at least one selected from the group consisting of: platinum-based catalysts, palladium-based catalysts, rhodium-based catalysts, ruthenium-based catalysts, nickel-based catalysts, copper-based catalysts, cobalt-based catalysts, tin-based catalysts, palladium-based catalysts, and iridium-based catalysts.

[0022] According to the embodiments, the ion-conducting insulating layer may contain anionic ionomers.

[0023] According to the embodiments, the catalyst layer may have a thickness of 1 to 40 μm.

[0024] According to the embodiments, the ion exchange membrane can have a thickness of 80 to 100 μm.

[0025] According to the embodiments, the thickness of the catalyst layer can be 0.01 to 0.5 relative to the total thickness of the ion exchange membrane.

[0026] According to the embodiments, the catalyst content in the catalyst layer can be 1 to 2 wt.%.

[0027] Meanwhile, according to another aspect of this invention, an electrochemical system comprising an ion exchange membrane, a negative electrode, and a positive electrode is provided.

[0028] The terms “first” and “second” are used in this document to explain various elements, and these terms are used only to distinguish one constituent element from other constituent elements.

[0029] The technical terms used herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0030] Unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” are intended to include the plural forms.

[0031] It should be understood that the terms “comprising,” “including,” “having,” etc., are used herein to specify the presence of the described feature, whole, step, component, or combination thereof, but do not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0032] In this invention, when referring to the formation of a layer or element on or above other layers or elements, it means that the layer or element is formed directly on those layers or elements, or that other layers or elements may be formed separately between those layers, on an object, or on a substrate.

[0033] Although the present invention can take various forms and be modified in various ways, specific embodiments will be illustrated and explained in detail below. However, this is not intended to limit the invention to the specific disclosure, and it should be understood that the invention includes all modifications, equivalents, or substitutions without departing from the spirit and scope of the invention.

[0034] The invention will now be described in more detail.

[0035] According to one aspect of the present invention, an ion exchange membrane is provided, comprising: a catalyst layer containing a hydration reaction catalyst, and an ion-conducting insulating layer.

[0036] The inventors discovered that when a catalyst layer containing a hydration reaction catalyst is added to a conventional ion exchange membrane containing an ion-conducting insulating material, gases such as hydrogen or oxygen that have already permeated the ion exchange membrane are hydrated by the catalyst, thereby further improving the gas barrier properties, and thus the present invention was completed.

[0037] According to one aspect of the present invention, an ion exchange membrane is provided, comprising: a catalyst layer containing a hydration reaction catalyst, and an ion-conducting insulating layer.

[0038] According to the example, the ion exchange membrane may include multiple ion-conducting insulating layers. Specifically, the ion-conducting insulating layers may include a first ion-conducting insulating layer and a second ion-conducting insulating layer.

[0039] Multiple ion-conducting insulating layers can exist adjacent to each other or spaced apart within the ion exchange membrane.

[0040] According to an example, an ion exchange membrane may include a catalyst layer containing a hydration reaction catalyst, a first ion-conducting insulating layer formed on one surface of the catalyst layer, and a second ion-conducting insulating layer formed on the other surface of the catalyst layer.

[0041] Figure 1 This is a schematic diagram of an ion exchange membrane according to an embodiment of the present invention.

[0042] refer to Figure 1 One form of ion exchange membrane can be identified, which includes a catalyst layer containing a hydration reaction catalyst, a first ion-conducting insulating layer formed on one surface of the catalyst layer, and a second ion-conducting insulating layer formed on the other surface of the catalyst layer.

[0043] Depending on the example, the catalyst layer can exist in a form that is isolated from the outside by an ion-conducting insulating layer.

[0044] Figure 2 This is a schematic diagram of an ion exchange membrane according to an embodiment of the present invention.

[0045] refer to Figure 2It can be confirmed that the ion exchange membrane includes a catalyst layer containing a hydration reaction catalyst; a first ion-conducting insulating layer formed on one surface of the catalyst layer; and a second ion-conducting insulating layer formed on the other surface of the catalyst layer, wherein the catalyst layer exists in a form that is isolated or isolated from the outside by the ion-conducting insulating layer.

[0046] According to another embodiment, the ion exchange membrane may include a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer.

[0047] Figure 3 This is a schematic diagram of an ion exchange membrane according to an embodiment of the present invention.

[0048] refer to Figure 3 It can be confirmed that one form of ion exchange membrane includes a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer.

[0049] In this case, the catalyst layer can exist in a form that is exposed to the outside without being isolated from the outside by an ion-conducting insulating layer.

[0050] Depending on the example, the ion exchange membrane may further include a strength-enhancing layer.

[0051] This strength-enhancing layer can exist in the form of being inserted between different ion-conducting insulating layers or between an ion-conducting insulating layer and a catalyst layer.

[0052] Figure 4 This is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0053] refer to Figure 4 It can be confirmed that the ion exchange membrane includes a catalyst layer containing a hydration reaction catalyst; a first ion-conducting insulating layer formed on one surface of the catalyst layer; and a second ion-conducting insulating layer formed on the other surface of the catalyst layer, with a strength-enhancing layer inserted between the catalyst layer and the first ion-conducting insulating layer.

[0054] Figure 5 This is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0055] refer to Figure 5 It can be confirmed that the ion exchange membrane includes a catalyst layer containing a hydration reaction catalyst; a first ion-conducting insulating layer formed on one surface of the catalyst layer; and a second ion-conducting insulating layer formed on the other surface of the catalyst layer, with a strength-enhancing layer inserted between the catalyst layer and the first ion-conducting insulating layer.

[0056] Figure 6 This is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0057] refer to Figure 6 It can be confirmed that the ion exchange membrane includes a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer, with a strength-enhancing layer inserted between the first ion-conducting insulating layer and the second ion-conducting insulating layer.

[0058] Figure 7 This is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0059] refer to Figure 7 One form of ion exchange membrane can be identified, which includes a first ion-conducting insulating layer; a strength-enhancing layer formed on the first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the strength-enhancing layer; a catalyst layer formed on the second ion-conducting insulating layer; and a third ion-conducting insulating layer formed on the catalyst layer.

[0060] Depending on the example, the strength-enhancing layer may include a porous polymer membrane.

[0061] Specifically, such a porous polymer membrane may include a porous polymer membrane comprising at least one polymer selected from the group consisting of polymers with polyolefin groups and fluorinated polyolefin groups (PTFE, etc.).

[0062] Furthermore, when a strength-enhancing layer is used, it can be formed by impregnation with an anionic ionomer and can be implemented in a way that maintains ionic conductivity with adjacent ion-conducting insulating layers, etc. This is intended to maintain the ionic conductivity of the entire ion exchange membrane.

[0063] Depending on the implementation, the catalyst layer may comprise a hydrated reactive catalyst and an anionic ionomer. This is intended to maintain the overall ionic conductivity of the ion exchange membrane. Specifically, the catalyst layer may be in the form in which the hydrated reactive catalyst material is dispersed within the anionic ionomer.

[0064] According to the embodiments described, the hydration reaction catalyst may include at least one selected from the group consisting of: platinum-based catalysts, palladium-based catalysts, rhodium-based catalysts, ruthenium-based catalysts, nickel-based catalysts, copper-based catalysts, cobalt-based catalysts, tin-based catalysts, palladium-based catalysts, and iridium-based catalysts. However, the present invention is not necessarily limited to the material composition of such catalysts, and as long as the catalyst is a commonly used hydration catalyst in the art to which this invention pertains, it can be used without particular limitation for the purpose of removing oxygen or hydrogen permeating an ion exchange membrane by a hydration reaction.

[0065] Depending on the example, the ion-conducting insulating layer may contain anionic ionomers.

[0066] The anionic ionomers mentioned in this article are materials having functional groups capable of transferring anions in the form of quaternary ammonium cations. Specifically, anionic ionomers may include carbazole.

[0067] Depending on the example, the thickness of the catalyst layer can be from approximately 1 to approximately 40 μm. If the catalyst layer is too thick, there is a problem of increased cost due to the addition of catalyst, and it may also have the disadvantage of acting as a resistor during anion conduction. If the catalyst layer is too thin, there may be a problem of reduced likelihood of hydrogen being adsorbed through the membrane, and increased hydrogen permeability.

[0068] Depending on the example, ion exchange membranes can have a thickness of approximately 80 to approximately 100 μm. If the overall thickness of the ion exchange membrane is too thick, there is a problem of increased membrane resistance, which may reduce the performance of the entire system and increase costs due to the need to use a large amount of material. If the thickness is too thin, there is a problem of a large amount of hydrogen gas generated by the electrochemical reaction of water permeating through the membrane, which may increase the risk of battery system explosion.

[0069] Depending on the example, the strength reinforcement layer can have a thickness of approximately 5 to approximately 15 μm. If the strength reinforcement layer is too thick, there is a problem of insufficient impregnation of the ionomer, and the strength reinforcement layer may act as a resistor in the film, which may degrade the performance of the entire system. If the thickness is too thin, problems such as cracking and rupture may occur due to the shrinkage and expansion of the film.

[0070] According to the example method, the thickness of the catalyst layer can be achieved in a ratio of approximately 0.01 to approximately 0.5% of the total thickness of the ion exchange membrane. If the thickness of the catalyst layer is too thick relative to the total thickness of the ion exchange membrane, it may be difficult to uniformly disperse the catalyst within the catalyst layer, which may lead to a higher catalyst content. If the thickness of the catalyst layer is too thin relative to the total thickness of the ion exchange membrane, a higher hydrogen permeability may occur.

[0071] Depending on the example, the catalyst content in the catalyst layer may be about 1 to about 2 wt.% or less relative to the ionomer. If the catalyst content in the catalyst layer is too low, there may be a problem that the membrane must be produced to increase the catalyst content per unit area. If the catalyst content in the catalyst layer is too high, there may be a problem of increased resistance and decreased performance of the overall system.

[0072] Meanwhile, this ion exchange membrane can be produced by the following methods.

[0073] First, anionic ionomers can form an ion-conducting insulating layer. Anionic ionomers can be used alone or in combination with dispersants or solvents to form anionic ionomer compositions.

[0074] A catalyst layer can be formed from a catalyst composition in which the hydration reaction catalyst is dispersed in an anionic ionomer.

[0075] When anionic ionomers are applied, general methods for forming coatings in the technical field to which this invention pertains can be used, such as bar coating or spray coating.

[0076] When an ion exchange membrane comprises a catalyst layer containing a hydration reaction catalyst; a first ion-conducting insulating layer formed on one surface of the catalyst layer; and a second ion-conducting insulating layer formed on the other surface of the catalyst layer, the ion exchange membrane can be produced by the following method.

[0077] First, an anionic ionomer or a composition containing anionic ionomer is applied to a release film. It is then dried to form a first ion-conducting insulating layer.

[0078] Then, the catalyst composition in which the hydration reaction catalyst is dispersed in the ion ionomer is applied onto the first ion-conducting insulating layer. At this time, the catalyst content in the catalyst composition is as described above. It is then dried to form a catalyst layer.

[0079] Then, the anionic ionomer or a composition containing the anionic ionomer is applied again to the catalyst layer. It is then dried to form a second ion-conducting insulating layer.

[0080] Drying can be carried out at about 80°C for about 50 minutes, and depending on the type and amount of solvent used, it can be done by natural drying or hot drying.

[0081] This method allows for the production of ion exchange membranes with a three-layer structure, wherein a catalyst layer is inserted between a first ion-conducting insulating layer and a second ion-conducting insulating layer.

[0082] When an ion exchange membrane comprises a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer, the ion exchange membrane can be produced by the following method.

[0083] First, an anionic ionomer or a composition containing anionic ionomer is applied to a release film. It is then dried to form a first ion-conducting insulating layer.

[0084] Then, an anionic ionomer or a composition containing anionic ionomer is applied onto the first ion-conducting insulating layer. It is then dried to form the second ion-conducting insulating layer.

[0085] Then, the catalyst composition in which the hydration reaction catalyst is dispersed in the ion ionomer is applied to the second ion-conducting insulating layer. At this time, the catalyst content in the catalyst composition is as described above. It is then dried to form a catalyst layer.

[0086] Drying can be carried out at about 80°C for about 50 minutes, and depending on the type and amount of solvent used, it can be done by natural drying or hot drying.

[0087] This method allows for the production of ion exchange membranes with a three-layer structure, in which the catalyst layer is exposed to the outside.

[0088] When the ion exchange membrane also includes a strength enhancement layer, the ion exchange membrane can be produced by the following methods.

[0089] First, an anionic ionomer or a composition containing anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dry, a porous polymer film for forming a strength-reinforcing layer is introduced, thereby impregnating the undried anionic ionomer into the porous polymer film. It is then dried to form a first ion-conducting insulating layer and a strength-reinforcing layer formed on the first ion-conducting insulating layer.

[0090] Then, the catalyst composition in which the hydration reaction catalyst is dispersed in the ionomer is applied to the strength-enhancing layer. At this time, the catalyst content in the catalyst composition is as described above. It is then dried to form a catalyst layer.

[0091] Then, the anionic ionomer or a composition containing the anionic ionomer is applied again to the catalyst layer. It is then dried to form a second ion-conducting insulating layer.

[0092] Drying can be carried out at about 80°C for about 50 minutes, and depending on the type and amount of solvent used, it can be done by natural drying or hot drying.

[0093] This method allows for the production of ion exchange membranes with a four-layer structure, wherein a catalyst layer is inserted between a first ion-conducting insulating layer and a second ion-conducting insulating layer, and a strength-enhancing layer is inserted between the catalyst layer and the first ion-conducting insulating layer.

[0094] When an ion exchange membrane is formed comprising a first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and a catalyst layer formed on the second ion-conducting insulating layer, and a strength-enhancing layer is inserted between the first ion-conducting insulating layer and the second ion-conducting insulating layer, the ion exchange membrane can be produced by the following method.

[0095] First, an anionic ionomer or a composition containing anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dry, a porous polymer film for forming a strength-reinforcing layer is introduced, thereby impregnating the undried anionic ionomer into the porous polymer film. It is then dried to form a first ion-conducting insulating layer and a strength-reinforcing layer formed on the first ion-conducting insulating layer.

[0096] Then, the anionic ionomer or a composition containing anionic ionomer is applied again to the strength-reinforcing layer. It is then dried to form a second ion-conducting insulating layer.

[0097] A catalyst composition in which the hydration reaction catalyst is dispersed in an ionomer is applied to a second ion-conducting insulating layer. The catalyst content in the catalyst composition is as described above. It is then dried to form a catalyst layer.

[0098] Drying can be carried out at about 80°C for about 50 minutes, and depending on the type and amount of solvent used, it can be done by natural drying or hot drying.

[0099] This method allows for the production of ion exchange membranes with a four-layer structure, wherein a strength-enhancing layer is inserted between a first ion-conducting insulating layer and a second ion-conducting insulating layer, and a catalyst layer is exposed to the outside.

[0100] When an ion exchange membrane is formed comprising a first ion-conducting insulating layer; a strength-enhancing layer formed on the first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the strength-enhancing layer; a catalyst layer formed on the second ion-conducting insulating layer; and a third ion-conducting insulating layer formed on the catalyst layer, the ion exchange membrane can be produced by the following method.

[0101] First, an anionic ionomer or a composition containing anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dry, a porous polymer film for forming a strength-reinforcing layer is introduced, thereby impregnating the undried anionic ionomer into the porous polymer film. It is then dried to form a first ion-conducting insulating layer and a strength-reinforcing layer formed on the first ion-conducting insulating layer.

[0102] Then, the anionic ionomer or a composition containing anionic ionomer is applied again to the strength-reinforcing layer. It is then dried to form a second ion-conducting insulating layer.

[0103] A catalyst composition in which the hydration reaction catalyst is dispersed in an ionomer is applied to a second ion-conducting insulating layer. The catalyst content in the catalyst composition is as described above. It is then dried to form a catalyst layer.

[0104] Individually, an anionic ionomer or a composition containing anionic ionomer is applied to a release film and then dried to form a third ion-conducting insulating layer.

[0105] The third ion-conducting insulating layer is bonded to the catalyst layer.

[0106] Drying can be carried out at about 80°C for about 50 minutes, and depending on the type and amount of solvent used, it can be done by natural drying or hot drying.

[0107] This method allows the production of ion exchange membranes with a five-layer structure, comprising: a first ion-conducting insulating layer; a strength-enhancing layer formed on the first ion-conducting insulating layer; a second ion-conducting insulating layer formed on the strength-enhancing layer; a catalyst layer formed on the second ion-conducting insulating layer; and a third ion-conducting insulating layer formed on the catalyst layer.

[0108] Meanwhile, according to another aspect of the present invention, an electrochemical system is provided, comprising an ion exchange membrane, a negative electrode, and a positive electrode.

[0109] At this point, the electrochemical system may include a membrane-electrode assembly (MEA) comprising an ion exchange membrane; a negative electrode bonded to one surface of the ion exchange membrane; and a positive electrode bonded to the other surface of the ion exchange membrane.

[0110] In such membrane electrode assemblies or electrochemical systems, other components besides the ion exchange membrane, such as negative electrodes, positive electrodes, electrolytes, etc., can be commonly used components in the technical field to which this invention pertains, and there are no particular limitations.

[0111] [Beneficial Effects] The ion exchange membrane according to the present invention can maintain high ion conductivity and durability, while having high gas barrier properties, thereby enabling electrochemical systems with excellent efficiency. Attached Figure Description

[0112] Figures 1 to 7 This is a schematic diagram of an ion exchange membrane according to an example of the present invention. Detailed Implementation

[0113] The effects and functions of the present invention will be described in more detail below through specific embodiments. However, these embodiments are provided for illustrative purposes only, and the scope of the present invention is not limited to these embodiments.

[0114] <Example> A composition containing 25 wt.% carbazole and 75 wt.% N-methyl-pyrrolidone (NMP) was used as an anionic ionomer composition.

[0115] Porous polypropylene membranes are used as porous polymer membranes for the strength reinforcement layer.

[0116] Using 50 wt.% Pt / C as the hydration reaction catalyst, Pt / C is available from TKK, and using a catalyst composition (1) dispersed in a composition containing 25 wt.% carbazole and 75 wt.% N-methyl-pyrrolidone (NMP) at a ratio of 1:100 or a catalyst composition (2) dispersed in a composition containing 25 wt.% carbazole and 75 wt.% N-methyl-pyrrolidone (NMP) at a ratio of 2:100.

[0117] Example 1 An anionic ionomer composition rod is coated onto a release film to a thickness of approximately 350 μm. Before it is completely dry, a porous polypropylene film is covered and the anionic ionomer composition is impregnated into the porous polypropylene film. It is then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a first ion-conducting insulating layer and a strength-enhancing layer.

[0118] The catalyst composition (1) rod was coated onto the strength enhancement layer to a thickness of about 200 μm, and then dried in a convection oven at about 80 °C for about 50 minutes to form a catalyst layer.

[0119] An anionic ionomer composition rod is coated onto the catalyst layer to a thickness of approximately 100 μm, and then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a second ion-conducting insulating layer.

[0120] Example 2 An anionic ionomer composition rod is coated onto a release film to a thickness of approximately 350 μm. Before it is completely dry, a porous polypropylene film is covered and the anionic ionomer composition is impregnated into the porous polypropylene film. It is then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a first ion-conducting insulating layer and a strength-enhancing layer.

[0121] An anionic ionomer composition rod is coated onto a strength-enhancing layer to a thickness of approximately 200 μm, and then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a second ion-conducting insulating layer.

[0122] The catalyst composition (2) rod is coated on the second ion-conducting insulating layer to a thickness of about 100 μm, and then dried in a convection oven at about 80 °C for about 50 minutes to form a catalyst layer.

[0123] Individually, an anionic ionomer composition rod is coated onto a release film to a thickness of approximately 100 μm, and then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a third ion-conducting insulating layer.

[0124] The third ion-conducting insulating layer is placed on the catalyst layer and laminated using a roller press at 120°C, 30MPa and 0.2m / min, and then the release film is removed.

[0125] Example 3 An anionic ionomer composition rod is coated onto a release film to a thickness of approximately 400 μm. Before it is completely dry, a porous polypropylene film is covered and the anionic ionomer composition is impregnated into the porous polypropylene film. It is then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a first ion-conducting insulating layer and a strength-enhancing layer.

[0126] An anionic ionomer composition rod is coated onto a strength-enhancing layer to a thickness of approximately 200 μm, and then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a second ion-conducting insulating layer.

[0127] The catalyst composition (1) rod is coated on the second ion-conducting insulating layer to a thickness of about 200 μm, and then dried in a convection oven at about 80 °C for about 50 minutes to form a catalyst layer.

[0128] Comparative Example 1 An anionic ionomer composition rod is coated onto a release film to a thickness of approximately 400 μm. Before it is completely dry, a porous polypropylene film is covered and the anionic ionomer composition is impregnated into the porous polypropylene film. It is then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a first ion-conducting insulating layer and a strength-enhancing layer.

[0129] An anionic ionomer composition rod is coated onto a strength-enhancing layer to a thickness of approximately 400 μm, and then dried in a convection oven at approximately 80°C for approximately 50 minutes to form a second ion-conducting insulating layer.

[0130] Fabrication of membrane electrode assemblies The membranes produced in the examples and comparative examples were stacked with hydrogen generation electrodes and oxygen generation electrodes, and bonded using a roll press at 120°C, 30 MPa, and 0.2 m / min to prepare membrane electrode assemblies. The electrode area was fabricated to be 100 cm². 2 .

[0131] Hydrogen permeation assessment When the current density of the electrolytic stack is maintained at 1.5 A / cm 2 Simultaneously, while circulating a 1M KOH aqueous solution at 60°C, the concentration of hydrogen gas present in the oxygen generated at the oxygen generating electrode was measured. Theoretically, hydrogen gas cannot be generated on the oxygen generating electrode side, but hydrogen gas generated on the hydrogen generating electrode side opposite to the membrane can permeate the membrane and move to the oxygen generating electrode side, thus making hydrogen gas detectable.

[0132] The hydrogen concentration was measured using a sensor installed on the test station, which is available from CNL.

[0133] The results are summarized in the table below.

[0134] [Table 1]

[0135] In the comparative example, the hydrogen concentration in the gas produced from the oxygen generating electrode was measured to be approximately 2.61%.

[0136] Conversely, in Examples 1 to 3, it was confirmed that the hydrogen concentration in the gas generated from the oxygen generating electrode was about 0.8% to about 1.09%, which was reduced by about 60% to about 70% compared to the comparative example.

[0137] This is believed to be because the hydrogen that has permeated into the membrane is hydrated by the hydration reaction catalyst present inside the ion exchange membrane according to an example of the invention, and therefore cannot pass through the membrane.

Claims

1. An ion exchange membrane, comprising: Catalyst layer containing hydration reaction catalyst, and Ion-conducting insulating layer.

2. The ion exchange membrane according to claim 1, wherein, The ion-conducting insulating layer includes a first ion-conducting insulating layer and a second ion-conducting insulating layer.

3. The ion exchange membrane according to claim 1, comprising: A catalyst layer containing a hydration reaction catalyst; A first ion-conducting insulating layer is formed on one surface of the catalyst layer; and A second ion-conducting insulating layer is formed on another surface of the catalyst layer.

4. The ion exchange membrane according to claim 1, wherein, The catalyst layer exists in a form that is isolated from the outside by the ion-conducting insulating layer.

5. The ion exchange membrane according to claim 1, comprising: First ion-conducting insulating layer; A second ion-conducting insulating layer is formed on the first ion-conducting insulating layer; and A catalyst layer formed on the second ion-conducting insulating layer.

6. The ion exchange membrane according to claim 1 further includes a strength enhancement layer.

7. The ion exchange membrane according to claim 6, wherein, The strength-enhancing layer comprises a porous polymer membrane.

8. The ion exchange membrane according to claim 1, wherein, The catalyst layer comprises a hydrated reaction catalyst and an anionic ionomer.

9. The ion exchange membrane according to claim 1, wherein, The hydration reaction catalyst includes at least one selected from the group consisting of: platinum-based catalysts, palladium-based catalysts, rhodium-based catalysts, ruthenium-based catalysts, nickel-based catalysts, copper-based catalysts, cobalt-based catalysts, tin-based catalysts, palladium-based catalysts, and iridium-based catalysts.

10. The ion exchange membrane according to claim 1, wherein, Each of the ion-conducting insulating layers independently contains anionic ionomers.

11. The ion exchange membrane according to claim 1, wherein, The catalyst layer has a thickness of 1 to 40 μm.

12. The ion exchange membrane according to claim 1, wherein, The thickness is 80 to 100 μm.

13. The ion exchange membrane according to claim 1, wherein, The thickness of the catalyst layer is 0.01 to 0.5 relative to the total thickness of the ion exchange membrane.

14. The ion exchange membrane according to claim 1, wherein, The catalyst content in the catalyst layer is 1 to 2 wt. relative to the ionomer.

15. An electrochemical system comprising an ion exchange membrane, a negative electrode, and a positive electrode as described in claim 1.

Images