Ion exchange membrane and electrochemical system comprising ion exchange membrane

Abstract

The present invention relates to an ion exchange membrane and an electrochemical system comprising the ion exchange membrane. The ion exchange membrane according to the present invention can realize an electrochemical system with excellent efficiency by maintaining high ion conductivity and durability as well as having high gas barrier properties.

Description

Ion exchange membranes and electrochemical systems comprising ion exchange membranes

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0144774, filed October 26, 2023, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to an ion exchange membrane and an electrochemical system including an ion exchange membrane.

[0004]

[0005] As the problem of climate change due to global warming becomes more serious, interest is focusing on research into alternative energy sources to reduce greenhouse gas emissions.

[0006] Among them, polymer electrolyte membrane fuel cells and water electrolysis are pollution-free systems that utilize the chemical reaction energy of hydrogen and oxygen. They have high power density and energy conversion efficiency and can be miniaturized, so they have a wide range of applications, such as portable power sources for mobile communication equipment, transportation power sources for automobiles, and power generation systems for home and military use.

[0007] Membranes are a very important element in fuel cells and water electrolysis. These membranes must have high ionic conductivity and chemical, thermal, mechanical, and electrochemical stability, while also effectively blocking the movement of substances between the anode and cathode.

[0008] Water electrolysis is a technology that electrochemically decomposes water to produce hydrogen and oxygen. In the anion exchange membrane water electrolysis (AEMWE) method, the unit cell includes an anion exchange membrane, a cathode formed on one side of the anion exchange membrane, and an anode formed on the other side of the anion exchange membrane.

[0009] Multiple such unit cells are stacked in series to form a water electrolysis stack. The water electrolysis stack receives an alkaline aqueous solution from an electrolyte tank, decomposes water, and generates hydrogen and hydroxide ions at the anode. The hydroxide ions generated here are transferred to the other side through an anion exchange membrane, and an electrochemical reaction occurs at the cathode, generating oxygen from the hydroxide ions.

[0010] At this time, the anion exchange membrane is an intermediate electrolyte membrane, and must have high conductivity for hydroxide ions, while at the same time not allowing hydrogen and oxygen generated by water electrolysis to pass through.

[0011] When an anion exchange membrane is used in an electrochemical system such as the above, it can be operated under relatively high pH conditions, so it has the advantage of being able to use a low-cost catalyst instead of the existing expensive platinum-based precious metal catalyst, thereby reducing the operating cost of the entire system.

[0012] However, due to the low anion conductivity, high gas permeability, and low durability of the anion exchange membrane used in these anion exchange membrane-based electrochemical systems, research on this is necessary.

[0013]

[0014] The present disclosure seeks to provide an ion exchange membrane having high conductivity for anions, low gas permeability, and excellent durability.

[0015] In addition, the present disclosure seeks to provide an electrochemical system including an ion exchange membrane.

[0016]

[0017] According to one aspect of the present invention, an ion exchange membrane is provided, comprising a catalyst layer including a hydration reaction catalyst and an ion conductive insulating layer.

[0018]

[0019] According to one example, the ion conductive insulating layer may include a first ion conductive insulating layer and a second ion conductive insulating layer.

[0020]

[0021] According to one example, the ion exchange membrane may include a catalyst layer including a hydration reaction catalyst; a first ion conductive insulating layer formed on one side of the catalyst layer; and a second ion conductive insulating layer formed on the other side of the catalyst layer.

[0022]

[0023] According to one example, the catalyst layer may exist in a form blocked from the outside by the ion-conducting insulating layer.

[0024]

[0025] According to one example, 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 conductive insulating layer.

[0026]

[0027] In one example, the ion exchange membrane may further comprise a strength reinforcing layer.

[0028]

[0029] In one example, the strength reinforcing layer may include a porous polymer membrane.

[0030]

[0031] In one example, the catalyst layer may include a hydration reaction catalyst and an anionic ionomer.

[0032]

[0033] According to one example, the hydration reaction catalyst may include at least one selected from the group consisting of a platinum-based catalyst, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, a nickel-based catalyst, a copper-based catalyst, a cobalt-based catalyst, a tin-based catalyst, a palladium-based catalyst, and an iridium-based catalyst.

[0034]

[0035] In one example, the ion-conductive insulating layer may include an anionic ionomer.

[0036]

[0037] In one example, the thickness of the catalyst layer may be 1 to 40 μm.

[0038]

[0039] In one example, the ion exchange membrane may have a thickness of 80 to 100 μm.

[0040]

[0041] In one example, the thickness of the catalyst layer may be 0.01 to 0.5 relative to the total thickness of the ion exchange membrane.

[0042]

[0043] In one example, the catalyst content in the catalyst layer may be 1 to 2 wt%.

[0044]

[0045] Meanwhile, according to another aspect of the present invention, an electrochemical system is provided, including an ion exchange membrane, a cathode, and an anode.

[0046]

[0047] In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

[0048] Additionally, the terms used herein are merely used to describe exemplary embodiments and are not intended to limit the present invention.

[0049] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0050] In this specification, the terms “comprise,” “include,” or “have” are intended to describe a feature, number, step, component, or combination thereof implemented, but do not exclude the possibility of one or more other features, numbers, steps, components, combinations, or additions thereof.

[0051] Additionally, in this specification, when each layer or element is referred to as being formed “on” or “over” each layer or element, it means that each layer or element is formed directly on each layer or element, or that other layers or elements may be additionally formed between each layer, on the object, or on the substrate.

[0052] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this does not limit the invention to a specific disclosed form, but rather encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0053]

[0054] Hereinafter, the present invention will be described in detail.

[0055]

[0056] According to one aspect of the present invention, an ion exchange membrane is provided, comprising a catalyst layer including a hydration reaction catalyst and an ion conductive insulating layer.

[0057]

[0058] The inventors of the present invention discovered that when a catalyst layer containing a hydration reaction catalyst is added to an existing ion exchange membrane containing an ion conductive insulating material, gases such as hydrogen or oxygen that have permeated the ion exchange membrane are hydrated by the catalyst, thereby further improving the gas barrier property, and thus completed the present invention.

[0059]

[0060] According to one aspect of the present invention, an ion exchange membrane is provided, comprising a catalyst layer including a hydration reaction catalyst and an ion conductive insulating layer.

[0061] In one example, the ion exchange membrane may include a plurality of ion-conductive insulating layers. Specifically, the ion-conductive insulating layers may include a first ion-conductive insulating layer and a second ion-conductive insulating layer.

[0062] The multiple ion-conducting insulating layers may be adjacent to each other or spaced apart from each other within the ion exchange membrane.

[0063]

[0064] According to one example, the ion exchange membrane may include a catalyst layer including a hydration reaction catalyst; a first ion conductive insulating layer formed on one side of the catalyst layer; and a second ion conductive insulating layer formed on the other side of the catalyst layer.

[0065]

[0066] Figure 1 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0067] Referring to FIG. 1, one form of an ion exchange membrane can be confirmed, which includes a catalyst layer including a hydration reaction catalyst; a first ion conductive insulating layer formed on one side of the catalyst layer; and a second ion conductive insulating layer formed on the other side of the catalyst layer.

[0068]

[0069] According to one example, the catalyst layer may exist in a form blocked from the outside by the ion-conducting insulating layer.

[0070] Figure 2 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0071] Referring to FIG. 2, in an ion exchange membrane including a catalyst layer including a hydration reaction catalyst; a first ion conductive insulating layer formed on one side of the catalyst layer; and a second ion conductive insulating layer formed on the other side of the catalyst layer, it can be confirmed that the catalyst layer exists in a form in which it is blocked or isolated from the outside by the ion conductive insulating layer.

[0072]

[0073] According to another example, 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 conductive insulating layer.

[0074] Figure 3 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0075]

[0076] Referring to FIG. 3, one form of an ion exchange membrane can be confirmed, which includes a first ion conductive insulating layer; a second ion conductive insulating layer formed on the first ion conductive insulating layer; and a catalyst layer formed on the second conductive insulating layer.

[0077] In this case, the catalyst layer may exist in a form exposed to the outside without being blocked from the outside by the ion-conducting insulating layer.

[0078]

[0079] In one example, the ion exchange membrane may further comprise a strength reinforcing layer.

[0080] Such a strength reinforcing layer may be present between different ion-conducting insulating layers, or between an ion-conducting insulating layer and a catalyst layer.

[0081]

[0082] Figure 4 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0083] Referring to FIG. 4, it can be seen that the catalyst layer includes a hydration reaction catalyst; a first ion-conducting insulating layer formed on one side of the catalyst layer; and a second ion-conducting insulating layer formed on the other side of the catalyst layer, and a strength reinforcing layer is interposed between the catalyst layer and the first ion-conducting insulating layer.

[0084]

[0085] Figure 5 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0086] Referring to FIG. 5, it can be seen that the catalyst layer includes a hydration reaction catalyst; a first ion-conducting insulating layer formed on one side of the catalyst layer; and a second ion-conducting insulating layer formed on the other side of the catalyst layer, and a strength reinforcing layer is interposed between the catalyst layer and the second ion-conducting insulating layer.

[0087]

[0088] Figure 6 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0089] Referring to FIG. 6, it can be confirmed that the device 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 conductive insulating layer, and a strength reinforcing layer is interposed between the first ion-conducting insulating layer and the second ion-conducting insulating layer.

[0090]

[0091] Figure 7 is a schematic diagram of an ion exchange membrane according to an example of the present invention.

[0092] Referring to FIG. 7, the form of an ion exchange membrane including a first ion conductive insulating layer, a strength reinforcing layer formed on the first ion conductive insulating layer, a second ion conductive insulating layer formed on the strength reinforcing layer, a catalyst layer formed on the second ion conductive insulating layer, and a third ion conductive insulating layer formed on the catalyst layer can be confirmed.

[0093]

[0094] In one example, the strength reinforcing layer may include a porous polymer membrane.

[0095] Specifically, examples of such porous polymer membranes include porous polymer membranes containing one or more polymers selected from the group consisting of polyolefin series and fluorinated polyolefin series (such as PTFE) polymers.

[0096]

[0097] In addition, when a strength reinforcing layer is used, the strength reinforcing layer may be formed in a form impregnated with an anionic ionomer, so as to maintain ion conductivity with an adjacent ion-conducting insulating layer, etc. This is to maintain ion conductivity throughout the ion exchange membrane.

[0098]

[0099] In one example, the catalyst layer may include a hydration reaction catalyst and an anionic ionomer. This is to maintain ion conductivity throughout the ion exchange membrane. Specifically, the catalyst layer may be in a form in which the hydration reaction catalyst material is dispersed in the anionic ionomer.

[0100]

[0101] For example, the hydration reaction catalyst may include at least one selected from the group consisting of a platinum-based catalyst, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, a nickel-based catalyst, a copper-based catalyst, a cobalt-based catalyst, a tin-based catalyst, a palladium-based catalyst, and an iridium-based catalyst. However, the present invention is not necessarily limited to the material composition of such a catalyst, and any hydration reaction catalyst generally used in the technical field to which the present invention pertains may be used without any particular limitation for the purpose of removing oxygen or hydrogen gas that permeates into an ion exchange membrane through a hydration reaction.

[0102]

[0103] In one example, the ion-conductive insulating layer may include an anionic ionomer.

[0104] The anionic ionomer referred to herein is a material having a functional group capable of transferring anions in the form of quaternary ammonium cations. Specifically, the anionic ionomer may include carbazole.

[0105]

[0106] For example, the catalyst layer may have a thickness of about 1 to about 40 μm. If the catalyst layer is too thick, there is a problem of increased cost due to the addition of catalyst, and a disadvantage of acting as resistance during anion conduction may occur. If the catalyst layer is too thin, the probability of hydrogen permeating the membrane being adsorbed may decrease, which may cause a problem of increased hydrogen permeability.

[0107]

[0108] For example, the ion exchange membrane may have a thickness of about 80 to about 100 μm. If the entire ion exchange membrane is too thick, the resistance of the membrane may increase, which may lower the performance of the entire system. In addition, the cost may increase due to the need for a large amount of materials. If the thickness is too thin, the hydrogen generated by the electrochemical reaction of water may permeate through the membrane in large amounts, which may increase the risk of explosion in the battery system.

[0109]

[0110] For example, the strength-reinforcing layer may have a thickness of about 5 to about 15 μm. If the thickness of the strength-reinforcing layer is too thick, problems such as insufficient ionomer impregnation may occur, and the strength-reinforcing layer may act as resistance within the membrane, resulting in a decrease in the performance of the entire system. If the thickness is too thin, problems such as cracking and breakage due to shrinkage and expansion of the membrane may occur.

[0111]

[0112] For example, the thickness of the catalyst layer may be implemented at a ratio of about 0.01 to about 0.5 relative to 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, uniform dispersion of the catalyst within the catalyst layer may become difficult, and a problem of increased catalyst content may occur. If the thickness of the catalyst layer is too thin relative to the total thickness of the ion exchange membrane, a problem of increased hydrogen permeability may occur.

[0113]

[0114] In one example, the catalyst content within the catalyst layer may be about 1 to about 2 wt% or less relative to the ionomer. If the catalyst content within the catalyst layer is too low, the membrane may need to be manufactured with a thicker thickness to increase the catalyst content per unit area of ​​the membrane, and if the catalyst content within the catalyst layer is too high, the resistance may increase, resulting in a decrease in the performance of the entire system.

[0115]

[0116] Meanwhile, such ion exchange membranes can be manufactured by the following method.

[0117]

[0118] First, the ion-conductive insulating layer can be formed by an anionic ionomer. The anionic ionomer can be used on its own, or in the form of an anionic ionomer composition together with a dispersant, solvent, etc.

[0119]

[0120] And, the catalyst layer can be formed by a catalyst composition in which a hydration reaction catalyst is dispersed in an anionic ionomer.

[0121] When applying an anionic ionomer, a general method used for forming a coating layer in the technical field to which the present invention belongs, such as bar coating or spray coating, can be used.

[0122]

[0123] When the ion exchange membrane comprises a catalyst layer including a hydration reaction catalyst; a first ion conductive insulating layer formed on one side of the catalyst layer; and a second ion conductive insulating layer formed on the other side of the catalyst layer, the membrane can be manufactured by the following method.

[0124] First, an anionic ionomer or a composition containing an anionic ionomer is applied to a release film. This is then dried to form a first ion-conductive insulating layer.

[0125] Then, a catalyst composition in which a hydration reaction catalyst is dispersed in an ionic ionomer is applied onto the first ion-conducting insulating layer. At this time, the content of the catalyst in the catalyst composition is as described above. Then, the catalyst layer is formed by drying.

[0126] Then, an anionic ionomer or a composition containing an anionic ionomer is applied again on the catalyst layer. Then, this is dried to form a second ion-conductive insulating layer.

[0127] Drying can be carried out for about 50 minutes at about 80℃, and can be carried out by natural drying or heat drying depending on the type and amount of solvent used.

[0128] By this method, an ion exchange membrane having a three-layered layered structure and a catalyst layer interposed between the first and second ion-conducting insulating layers can be manufactured.

[0129]

[0130] When the 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 conductive insulating layer, it can be manufactured by the following method.

[0131] First, an anionic ionomer or a composition containing an anionic ionomer is applied to a heterogeneous film. This is then dried to form a first ion-conductive insulating layer.

[0132] Then, an anionic ionomer or a composition containing an anionic ionomer is applied again on the first ion-conducting insulating layer. Then, the anionic ionomer is dried to form a second ion-conducting insulating layer.

[0133] Then, a catalyst composition in which a hydration reaction catalyst is dispersed in an ionic ionomer is applied onto the second ion-conducting insulating layer. At this time, the content of the catalyst in the catalyst composition is as described above. Then, the catalyst layer is formed by drying.

[0134] Drying can be carried out for about 50 minutes at about 80℃, and can be carried out by natural drying or heat drying depending on the type and amount of solvent used.

[0135] By this method, an ion exchange membrane having a three-layered layered structure and a catalyst layer exposed to the outside can be manufactured.

[0136]

[0137] When the ion exchange membrane further comprises a strength reinforcing layer, it can be manufactured by the following method.

[0138] First, an anionic ionomer or a composition containing an anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dried, a porous polymer membrane for forming a strength-reinforcing layer is introduced so that the anionic ionomer, which is not yet dried, is impregnated into the porous polymer membrane. This is dried to form a first ion-conductive insulating layer and a strength-reinforcing layer formed on the first conductive insulating layer.

[0139] Then, a catalyst composition containing a hydration reaction catalyst dispersed in an ionic ionomer is applied onto the strength reinforcing layer. The catalyst content in the catalyst composition is as described above. This is then dried to form a catalyst layer.

[0140] Then, an anionic ionomer or a composition containing an anionic ionomer is applied again on the catalyst layer. Then, this is dried to form a second ion-conductive insulating layer.

[0141] Drying can be carried out for about 50 minutes at about 80℃, and can be carried out by natural drying or heat drying depending on the type and amount of solvent used.

[0142] By this method, an ion exchange membrane having a four-layered layered structure, a catalyst layer interposed between the first and second ion-conducting insulating layers, and a strength reinforcing layer interposed between the catalyst layer and the first ion-conducting insulating layer can be manufactured.

[0143]

[0144] When the 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 conductive insulating layer, and a strength reinforcing layer is interposed between the first ion-conducting insulating layer and the second ion-conducting insulating layer, the membrane can be manufactured by the following method.

[0145] First, an anionic ionomer or a composition containing an anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dried, a porous polymer membrane for forming a strength-reinforcing layer is introduced so that the anionic ionomer, which is not yet dried, is impregnated into the porous polymer membrane. This is dried to form a first ion-conductive insulating layer and a strength-reinforcing layer formed on the first conductive insulating layer.

[0146] Then, on the strength reinforcing layer, an anionic ionomer or a composition containing an anionic ionomer is applied again. Then, this is dried to form a second ion-conductive insulating layer.

[0147] A catalyst composition in which a hydration reaction catalyst is dispersed in an ionic ionomer is applied onto the second ion-conducting insulating layer. The content of the catalyst in the catalyst composition is as described above. This is then dried to form a catalyst layer.

[0148] Drying can be carried out for about 50 minutes at about 80℃, and can be carried out by natural drying or heat drying depending on the type and amount of solvent used.

[0149] By this method, an ion exchange membrane having a four-layered layered structure, a strength reinforcing layer interposed between the first and second ion-conducting insulating layers, and a catalyst layer exposed to the outside can be manufactured.

[0150]

[0151] When the ion exchange membrane is in the form of a first ion-conducting insulating layer, a strength reinforcing layer formed on the first ion-conducting insulating layer, a second ion-conducting insulating layer formed on the strength reinforcing layer, a catalyst layer formed on the second ion-conducting insulating layer, and a third ion-conducting insulating layer formed on the catalyst layer, it can be manufactured by the following method.

[0152] First, an anionic ionomer or a composition containing an anionic ionomer is applied to a release film. Then, before the anionic ionomer is completely dried, a porous polymer membrane for forming a strength-reinforcing layer is introduced so that the anionic ionomer, which is not yet dried, is impregnated into the porous polymer membrane. This is dried to form a first ion-conductive insulating layer and a strength-reinforcing layer formed on the first conductive insulating layer.

[0153] Then, on the strength reinforcing layer, an anionic ionomer or a composition containing an anionic ionomer is applied again. Then, this is dried to form a second ion-conductive insulating layer.

[0154] A catalyst composition in which a hydration reaction catalyst is dispersed in an ionic ionomer is applied onto the second ion-conducting insulating layer. The content of the catalyst in the catalyst composition is as described above. This is then dried to form a catalyst layer.

[0155] Separately, an anionic ionomer or a composition containing an anionic ionomer is applied to the heterogeneous film and dried to form a third ion-conductive insulating layer.

[0156] The third ion-conducting insulating layer is bonded on the catalyst layer.

[0157] Drying can be carried out for approximately 50 minutes at 80°C, and can be carried out by natural drying or heat drying depending on the type and amount of solvent used.

[0158] By this method, an ion exchange membrane having a five-layered layered structure can be manufactured, which includes a first ion conductive insulating layer, a strength reinforcing layer formed on the first ion conductive insulating layer, a second ion conductive insulating layer formed on the strength reinforcing layer, a catalyst layer formed on the second ion conductive insulating layer, and a third ion conductive insulating layer formed on the catalyst layer.

[0159]

[0160] Meanwhile, according to another aspect of the present invention, an electrochemical system is provided, including an ion exchange membrane, a cathode, and an anode.

[0161] At this time, the electrochemical system may include a membrane-electrode-assembly (MEA) including an ion exchange membrane, a cathode bonded to one side of the ion exchange membrane, and an anode bonded to the other side of the ion exchange membrane.

[0162] In such membrane-electrode-assembly or electrochemical system, other components, such as the cathode, anode, electrolyte, etc., excluding the ion exchange membrane, can be employed without any particular limitation as those commonly used in the technical field to which the present invention belongs.

[0163]

[0164] The ion exchange membrane according to the present invention can maintain high ion conductivity and durability, while also having high gas barrier properties, thereby enabling implementation of an electrochemical system with excellent efficiency.

[0165]

[0166] Figures 1 to 7 are schematic diagrams of ion exchange membranes according to an example of the present invention.

[0167]

[0168] Hereinafter, the functions and effects of the invention will be described in more detail through specific examples. However, these examples are provided merely as examples of the invention and do not define the scope of the invention.

[0169]

[0170] <Example>

[0171] As an anionic ionomer composition, a composition containing 25 wt% of carbazole and 75 wt% of N-methyl-pyrrolidone (NMP) was used.

[0172] A porous polypropylene film was used as the porous polymer membrane for the strength reinforcing layer.

[0173] As a hydration reaction catalyst, 50 wt% Pt / C from TKK was used, and a catalyst composition (1) containing 25 wt% of carbazole and 75 wt% of N-methyl-pyrrolidone (NMP) was dispersed in a ratio of 1:100, or a catalyst composition (2) containing 25 wt% of carbazole and 75 wt% of N-methyl-pyrrolidone (NMP) was dispersed in a ratio of 2:100.

[0174]

[0175] Example 1

[0176] An anionic ionomer composition was bar-coated on a release film to a thickness of about 350 μm. Before it was completely dried, a porous polypropylene film was covered to impregnate the anionic ionomer composition into the porous polypropylene film, which was then dried in a convection oven at about 80°C for about 50 minutes to form a first ion-conductive insulating layer and a strength-reinforcing layer.

[0177] After coating the catalyst composition (1) on the strength reinforcing layer with a thickness of about 200 μm, the catalyst layer was formed by drying it in a convection oven at about 80°C for about 50 minutes.

[0178] An anionic ionomer composition was bar-coated on the catalyst layer to a thickness of about 100 μm, and dried in a convection oven at about 80° C. for about 50 minutes to form a second ion-conducting insulating layer.

[0179]

[0180] Example 2

[0181] An anionic ionomer composition was bar-coated on a release film to a thickness of about 350 μm. Before it was completely dried, a porous polypropylene film was covered to impregnate the anionic ionomer composition into the porous polypropylene film, which was then dried in a convection oven at about 80°C for about 50 minutes to form a first ion-conductive insulating layer and a strength-reinforcing layer.

[0182] An anionic ionomer composition was bar-coated on the strength reinforcing layer to a thickness of about 200 μm, and dried in a convection oven at about 80° C. for about 50 minutes to form a second ion-conductive insulating layer.

[0183] After coating the catalyst composition (2) on the second ion-conducting insulating layer with a thickness of about 100 μm, the catalyst layer was formed by drying it in a convection oven at about 80° C. for about 50 minutes.

[0184] Separately, an anionic ionomer composition was bar-coated on a release film to a thickness of about 100 μm, and dried in a convection oven at about 80° C. for about 50 minutes to form a third ion-conductive insulating layer.

[0185] The third ion-conducting insulating layer was placed on the catalyst layer, laminated using a roll press at 120°C, 30 MPa, and 0.2 m / min, and then the release film was removed.

[0186]

[0187] Example 3

[0188] An anionic ionomer composition was bar-coated on a release film to a thickness of about 400 μm. Before it was completely dried, a porous polypropylene film was covered to impregnate the anionic ionomer composition into the porous polypropylene film, which was then dried in a convection oven at about 80°C for about 50 minutes to form a first ion-conductive insulating layer and a strength-reinforcing layer.

[0189] An anionic ionomer composition was bar-coated on the strength reinforcing layer to a thickness of about 200 μm, and dried in a convection oven at about 80° C. for about 50 minutes to form a second ion-conductive insulating layer.

[0190] After coating the catalyst composition (1) on the second ion-conducting insulating layer with a thickness of about 200 μm, the catalyst layer was formed by drying it in a convection oven at about 80° C. for about 50 minutes.

[0191]

[0192] Comparative Example 1

[0193] An anionic ionomer composition was bar-coated on a release film to a thickness of about 400 μm. Before it was completely dried, a porous polypropylene film was covered to impregnate the anionic ionomer composition into the porous polypropylene film, which was then dried in a convection oven at about 80°C for about 50 minutes to form a first ion-conductive insulating layer and a strength-reinforcing layer.

[0194] An anionic ionomer composition was bar-coated on the strength reinforcing layer to a thickness of about 400 μm, and dried in a convection oven at about 80° C. for about 50 minutes to form a second ion-conductive insulating layer.

[0195]

[0196] Fabrication of membrane-electrode-assembly

[0197] The membranes, hydrogen generation electrodes, and oxygen generation electrodes manufactured in the above examples and comparative examples were laminated and bonded using a roll press at 120°C, 30 MPa, and 0.2 m / min to manufacture a membrane-electrode assembly. The electrode area was 100 cm 2 It was produced with .

[0198]

[0199] Hydrogen permeation evaluation

[0200] The current density of the electrolysis stack was 1.5 A / cm while circulating a 1M KOH aqueous solution at 60℃. 2 When maintained, the concentration of hydrogen present in the oxygen generated on the oxygen generation electrode side was measured. Theoretically, hydrogen cannot be generated on the oxygen generation electrode side, but hydrogen generated on the hydrogen generation electrode side, which is on the opposite side of the membrane, can permeate the membrane and move toward the oxygen generation electrode, so hydrogen can be detected.

[0201] Hydrogen concentration was measured using a sensor installed in CNL's TEST STATION.

[0202]

[0203] The above results are summarized in the table below.

[0204] Example 1 Example 2 Example 3 Comparative Example 1 H2 Concentration (%) 0.80 0.77 1.09 2.61

[0205] In the comparative example, the concentration of hydrogen in the gas generated from the oxygen generation electrode was measured to be approximately 2.61%.

[0206] In comparison, in the cases of Examples 1 to 3, it can be confirmed that the concentration of hydrogen in the gas generated from the oxygen generation electrode is reduced by about 60 to about 70% compared to the comparative example, to about 0.8% to about 1.09%.

[0207] This is thought to be due to the hydrogen that has penetrated into the membrane being hydrated by the hydration reaction catalyst present inside the ion exchange membrane according to one embodiment of the present invention, and thus not passing through the membrane.

Claims

1. A catalyst layer including a hydration reaction catalyst, and comprising an ion-conducting insulating layer, Ion exchange membrane.

2. In paragraph 1, The ion conductive insulating layer comprises a first ion conductive insulating layer and a second ion conductive insulating layer. Ion exchange membrane.

3. In paragraph 1, A catalyst layer comprising a hydration reaction catalyst; A first ion-conducting insulating layer formed on one side of the catalyst layer; and comprising a second ion-conducting insulating layer formed on the other side of the catalyst layer; Ion exchange membrane.

4. In paragraph 1, The above catalyst layer exists in a form blocked from the outside by the ion conductive insulating layer. Ion exchange membrane.

5. In paragraph 1, First ion-conducting insulating layer; a second ion-conducting insulating layer formed on the first ion-conducting insulating layer; and Comprising a catalyst layer formed on the second conductive insulating layer, Ion exchange membrane.

6. In paragraph 1, Including an additional strength reinforcing layer, Ion exchange membrane.

7. In paragraph 6, The above strength reinforcing layer comprises a porous polymer membrane, Ion exchange membrane.

8. In paragraph 1, The above catalyst layer comprises a hydration reaction catalyst and an anionic ionomer. Ion exchange membrane.

9. In paragraph 1, The above hydration reaction catalyst comprises at least one selected from the group consisting of a platinum-based catalyst, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, a nickel-based catalyst, a copper-based catalyst, a cobalt-based catalyst, a tin-based catalyst, a palladium-based catalyst, and an iridium-based catalyst. Ion exchange membrane.

10. In paragraph 1, The above ion conductive insulating layers each independently comprise an anionic ionomer. Ion exchange membrane.

11. In paragraph 1, The thickness of the above catalyst layer is 1 to 40 ㎛, Ion exchange membrane.

12. In paragraph 1, With a thickness of 80 to 100 ㎛, Ion exchange membrane.

13. In paragraph 1, The thickness of the above catalyst layer is 0.01 to 0.5 relative to the total thickness of the ion exchange membrane. Ion exchange membrane.

14. In paragraph 1, The catalyst content in the above catalyst layer is 1 to 2 wt% relative to the ionomer. Ion exchange membrane.

15. An electrochemical system comprising an ion exchange membrane, a cathode, and an anode according to paragraph 1.

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