Membrane electrode assembly manufacturing method

Abstract

The present invention relates to a membrane electrode assembly manufacturing method comprising the steps of: (S1) forming a first catalyst layer on the other surface of a separation membrane having a first carrier film attached to one surface thereof; (S2) attaching a second carrier film to the other surface of the separation membrane on which the first catalyst layer is formed; (S3) removing the first carrier film attached to one surface of the separation membrane; and (S4) forming a second catalyst layer on one surface of the separation membrane from which the first carrier film is removed, wherein the second carrier film includes a first area corresponding to the first catalyst layer on the other surface of the separation membrane, and a second area, which is the remaining area that excludes the first area, and the second area of the second carrier film is coated with an adhesive on a surface facing the other surface of the separation membrane on which the first catalyst layer is formed.

Description

Method for manufacturing membrane electrode assemblies

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0118326, filed September 6, 2023, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Technology field

[0005] The present invention relates to a method for manufacturing a membrane electrode assembly.

[0006]

[0007] Hydrogen is expected to play a crucial role as a future energy storage medium. The use of infinite energy sources and sustainable, pollution-free renewable energy will highlight the issue of energy storage, and hydrogen is currently positioned as a viable alternative. Hydrogen is considered a highly valuable fuel that can replace existing fossil fuels in all areas without emitting harmful substances. Furthermore, various methods are being studied to convert renewable energy into hydrogen energy, with water electrolysis, or water electrolysis, occupying a key area.

[0008] The above water electrolysis technology is a technology that electrolyzes water to separate it into oxygen and hydrogen, and uses the hydrogen as fuel. The water electrolysis cell in which the above water electrolysis technology is implemented includes a catalyst electrode in which an electrochemical reaction occurs and a polymer electrolyte membrane that transfers hydrogen ions generated by the electrochemical reaction. In addition, a gas diffusion layer (GDL), a gasket, and a separator may be arranged on each side of the polymer electrolyte membrane.

[0009] At this time, the catalyst electrode for hydrogen production through water electrolysis technology is composed of a hydrogen evolution reaction (HER) electrode (cathode) that reduces water to generate hydrogen and an oxygen evolution reaction (OER) electrode (anode) that oxidizes water to generate oxygen, and a structure in which the cathode and the anode are bonded to both sides of the polymer electrolyte membrane without a gap between them is called a membrane electrode assembly (MEA).

[0010] The principle of water electrolysis is that water is supplied to the anode and oxygen gas, electrons and hydrogen ions (H + ) is decomposed into electrons, and the electrons are transferred to the cathode through an external circuit, and the hydrogen ions (H + ) passes through the polymer electrolyte membrane to the cathode. The electrons and hydrogen ions transferred to the cathode react to produce hydrogen gas.

[0011] Meanwhile, most conventional membrane electrode assembly (MEA) manufacturing methods, such as the direct coating method, directly coat the catalyst ink onto the separator all at once, which causes membrane swelling and reduces thickness uniformity due to wrinkles and electrode cracks. Furthermore, the spray method, which coats thinly multiple times, takes a considerable amount of manufacturing time, lowering productivity and causing significant loss of precious metal catalysts.

[0012] In addition, to solve the above problem, a decal transfer method was used to manufacture a membrane electrode assembly by coating an electrode on a transfer film (PTFE) and decaling the electrode on a separator using a hot pressing method. However, this also had the problem of low productivity and high process cost.

[0013] Accordingly, in order to solve the problems of the conventional membrane electrode assembly manufacturing method and to improve the processability, productivity and quality uniformity, a method of manufacturing a membrane electrode assembly of uniform shape without causing membrane swelling and electrode cracking while directly coating the catalyst ink at once was studied.

[0014] (Patent Document 1) KR 10-2023-0101340 A

[0015]

[0016] The problem to be solved by the present invention is to provide a method for manufacturing a membrane electrode assembly that can improve processability, productivity, and quality uniformity by proceeding with a direct coating method while preventing swelling of the separator and cracking of the electrode.

[0017]

[0018] The present invention provides a method for manufacturing a membrane electrode assembly.

[0019] (1) A method for manufacturing a membrane electrode assembly is provided, comprising: a step (S1) of forming a first catalyst layer on the other side of a separator having a first carrier film attached to one side; a step (S2) of attaching a second carrier film to the other side of the separator having the first catalyst layer formed thereon; a step (S3) of removing the first carrier film attached to the one side of the separator; and a step (S4) of forming a second catalyst layer on the one side of the separator from which the first carrier film has been removed, wherein the second carrier film includes a first region corresponding to the first catalyst layer on the other side of the separator and a second region which is the remaining region excluding the first region, and an adhesive is coated on the second region of the second carrier film on the side facing the other side of the separator having the first catalyst layer formed thereon.

[0020] (2) The present invention provides a method for manufacturing a membrane electrode assembly in the above (1), wherein the first region does not include the adhesive.

[0021] (3) The present invention provides a method for manufacturing a membrane electrode assembly, wherein in the above (1) or (2), the second carrier film of the above step (S2) is formed only by the second region.

[0022] (4) The present invention provides a method for manufacturing a membrane electrode assembly, wherein in any one of the above (1) to (3), the first catalyst layer and the second catalyst layer of the above step (S1) and the above step (S4) are each independently formed by coating the electrode catalyst slurry on the separator and then drying it.

[0023] (5) The present invention provides a method for manufacturing a membrane electrode assembly, wherein, in the above (4), the coating step is performed by at least one method selected from the group consisting of a slot die method, an inkjet coating method, a spray coating method, a screen printing method, a doctor blade method, and a gravure coating method.

[0024] (6) The present invention provides a method for manufacturing a membrane electrode assembly, wherein the thickness of the first carrier film and the second carrier film in steps (S1) and (S2) is greater than 10 µm and less than or equal to 200 µm in any one of the above (1) to (5).

[0025] (7) The present invention provides a method for manufacturing a membrane electrode assembly, wherein in any one of the above (1) to (6), the first carrier film and the second carrier film include at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene, tetrafluoroethylene-perfluoroalkylvinyl ether, ethylene / tetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyester.

[0026] (8) The present invention provides a method for manufacturing a membrane electrode assembly, wherein in any one of the above (1) to (7), the adhesive comprises at least one selected from the group consisting of an acrylic resin, a silicone resin, a rubber resin, a urethane resin, a polyester resin, and an epoxy resin.

[0027] (9) The present invention provides a method for manufacturing a membrane electrode assembly, wherein the separation membrane is a cation exchange separation membrane or an anion exchange separation membrane, in any one of the above (1) to (8).

[0028] (10) The present invention provides a method for manufacturing a membrane electrode assembly, wherein in any one of the above (1) to (9), the first catalyst layer is formed of an electrode catalyst slurry including at least one selected from the group consisting of Pt, Sn, Al, Au, Ag, C, Cd, Co, Cr, Cu, Ga, Hg, In, Mo, Nb, Ni, NiCo2O4, Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, and mixtures thereof.

[0029] (11) The present invention provides a method for manufacturing a membrane electrode assembly, wherein the second catalyst layer is formed of an electrode catalyst slurry comprising at least one selected from the group consisting of Ir, Pt, Au, Pd, Ag, Rh, Ru, Ni, Al, Mo, Cr, Cu, Ti, W, and mixtures thereof, in any one of the above (1) to (10).

[0030] (12) The present invention provides a method for manufacturing a membrane electrode assembly, wherein the membrane electrode assembly is a membrane electrode assembly for water electrolysis, in any one of (1) to (11).

[0031]

[0032] According to the method for manufacturing a membrane electrode assembly of the present invention, productivity and processability are excellent by using a direct coating method, and by preventing swelling in the membrane and cracks in the electrode catalyst layer, a membrane electrode assembly of uniform quality and a desired thickness can be manufactured.

[0033]

[0034] Figure 1 is a process schematic diagram of the membrane electrode assembly of the present invention.

[0035] In Fig. 2, (a) shows one side of the separator where the electrode is bonded, (b) shows the carrier film before being coated with an adhesive, (c) shows the second carrier film coated with the adhesive of Example 1, and (d) shows the second carrier film coated with the adhesive of Example 2.

[0036] In Fig. 3, (a) is a photograph showing the membrane electrode assembly of Example 1, and (b) is a photograph showing the electrode surface of Example 1.

[0037] Figure 4 is a photograph showing a phenomenon in which a portion of the electrode of Comparative Example 1 is peeled off.

[0038] Figure 5 is a photograph showing (a) a swelling phenomenon occurring in the membrane electrode assembly of Comparative Example 2, and (b) a photograph showing a crack occurring on the electrode surface of Comparative Example 2.

[0039]

[0040] Hereinafter, the present invention will be described in more detail to facilitate understanding. The terms and words used in this specification and claims should not be interpreted based on their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0041] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0042] In this specification, it should be understood that the terms “include,” “comprising,” or “having” are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0043]

[0044] Method for manufacturing membrane electrode assemblies

[0045] The present invention provides a method for manufacturing a membrane electrode assembly, comprising the steps of (S1) forming a first catalyst layer on the other side of a separator having a first carrier film attached to one side thereof, (S2) attaching a second carrier film to the other side of the separator having the first catalyst layer formed thereon, (S3) removing the first carrier film attached to the one side of the separator, and (S4) forming a second catalyst layer on the one side of the separator from which the first carrier film has been removed, wherein the second carrier film includes a first region corresponding to the first catalyst layer on the other side of the separator and a second region which is the remaining region excluding the first region, and an adhesive is coated on the second region of the second carrier film on the side facing the other side of the separator having the first catalyst layer formed thereon.

[0046] The conventional direct coating method has the problem that swelling occurs in the separator, causing wrinkles and cracks; the spray method requires a considerable amount of processing time and has the problem that there is a large loss of precious metals; and the decal transfer method has the problem that productivity is low and the manufacturing process is quite complicated because it requires separate electrode coating lines and electrode and separator coating lines.

[0047] Accordingly, the method for manufacturing a membrane electrode composite of the present invention can reduce the cost and time required for the process by using a direct coating method, can improve the contact area between the catalyst layer and the separator compared to the conventional method, prevent the swelling phenomenon that occurs in the separator, and at the same time, can prevent the peeling phenomenon that may occur between the catalyst layer and the carrier film during the catalyst layer formation process, thereby manufacturing a uniform and high-quality membrane electrode composite.

[0048]

[0049] The above step (S1) is a step of forming a first catalyst layer on the other side of the separator, to which a first carrier film is attached on one side of both sides of the separator. The first carrier film may serve to prevent deformation when directly coating the catalyst layer on the separator, and to prevent a swelling phenomenon occurring in the separator. The swelling phenomenon is a phenomenon in which a specific substrate expands or swells, and may refer to a swelling phenomenon of the separator due to a solvent included in an electrode catalyst slurry when forming a catalyst layer. In addition, when attaching the first carrier film, it must be attached in close contact with the separator without generating air bubbles, and the attachment method of the first carrier film may use a method of applying an adhesive, and additionally, a method of utilizing electrostatic attraction may also be used. The first carrier film may have an adhesive coated on a surface facing one side of the separator.

[0050] The first carrier film may be the same or different from the second carrier film, and in this specification, the carrier films attached to one side and the other side of the separator are referred to as the first carrier film and the second carrier film, respectively.

[0051] Additionally, the first catalyst layer may be a cathode (reduction electrode), and the second catalyst layer may be an anode (oxidation electrode).

[0052] The above step (S2) is a step of attaching a second carrier film coated with an adhesive to the other surface of the separator on which the first catalyst layer is formed. The second carrier film may play a role in preventing a swelling phenomenon occurring in the separator in the same manner as the first carrier film. However, when the second carrier film is attached to the other surface of the separator on which the first catalyst layer is already formed, a problem may arise in which a part of the first catalyst layer is peeled off by the adhesive. That is, a problem may arise in which a part of the already attached catalyst layer is peeled off by the carrier film attached to prevent the swelling phenomenon of the separator. Fig. 4 is a photograph showing a phenomenon in which a part of the electrode of Comparative Example 1 is peeled off. When a carrier film is attached directly onto the catalyst layer already coated on one surface of the separator, a part of the catalyst layer (electrode) may be peeled off in this way, and thus the electroreduction efficiency may be significantly reduced.

[0053] In order to prevent a problem in which a part of the first catalyst layer formed first in the step (S2) is peeled off by the second carrier film, thereby causing cracks or cracks, the manufacturing method of the present invention can divide the second carrier film into a first region corresponding to the first catalyst layer and a second region not corresponding to the first catalyst layer, and an adhesive is coated on the surface of the second region facing the other surface of the separator on which the first catalyst layer is formed. That is, by not coating the adhesive on the first region and coating the adhesive only on the second region not corresponding to the first catalyst layer, the adhesive does not come into contact with the first catalyst layer, thereby preventing the peeling phenomenon of the first catalyst layer.

[0054] In Fig. 2, (a) shows one side of the separator where the electrode is bonded, (b) shows the carrier film before being coated with an adhesive, (c) shows the second carrier film coated with the adhesive of Example 1, and (d) shows the second carrier film coated with the adhesive of Example 2.

[0055] Referring to (c) of the above drawing 2, the first region is a region corresponding to the first catalyst layer, and a plurality of first regions may be formed in the center of the second carrier film, and the second region may correspond to a region surrounding the first region.

[0056] In addition, according to one embodiment of the present invention, the second carrier film of the step (S2) may be formed only of the second region. Referring to (d) of FIG. 2, by using a carrier film formed only of a region not corresponding to the first catalyst layer, excluding a region corresponding to the first catalyst layer, the problem of a portion of the first catalyst layer being peeled off can be solved.

[0057] In addition, the step (S3) is a step of removing the first carrier film attached in the step (S1), and the step (S4) is a step of forming a second catalyst layer on one side of the separator from which the first carrier film has been removed. The method of forming the second catalyst layer may be the same as the method of forming the first catalyst layer, and the swelling phenomenon may be prevented by the second carrier film. Thereafter, a step of cutting the membrane electrode assembly, in which the first catalyst layer and the second catalyst layer are coated on both sides of the separator, according to a desired area, may be further performed.

[0058]

[0059] According to one embodiment of the present invention, the first catalyst layer and the second catalyst layer of the step (S1) and the step (S4) may be formed by independently coating the electrode catalyst slurry on the separator and then drying it, and the coating may be performed by at least one method selected from the group consisting of a slot die method, an inkjet coating method, a spray coating method, a screen printing method, a doctor blade method, and a gravure coating method, and specifically, it may be performed by a non-contact printing method such as a slot die method or an inkjet coating method. In addition, in the manufacturing process of a membrane electrode assembly using a direct coating process, an R2R (roll-to-roll) process must be possible in order to improve productivity, and intermittent R2R methods such as screen printing and spray coating may have low productivity. Slot die, inkjet printing, and gravure printing can be applied as R2R processes capable of mass production, and among these, the most suitable method is a slot die or inkjet printing method as a non-contact method and has excellent electrochemical performance. The above slot die method has the advantage of being able to uniformly coat a large area electrode, and the inkjet printing method has the advantage of being able to form a low thickness electrode and enabling pattern formation and electrode design.

[0060] Additionally, the drying step can be performed at a temperature of 50°C to 100°C for 1 to 20 minutes.

[0061] Specifically, the first and second catalyst layers can be formed by coating an electrode catalyst slurry on the surface of the separator, respectively, and the electrode catalyst slurry can be prepared by mixing a catalyst with a solvent. The first catalyst layer may be formed of an electrode catalyst slurry including at least one selected from the group consisting of Pt, Sn, Al, Au, Ag, C, Cd, Co, Cr, Cu, Ga, Hg, In, Mo, Nb, Ni, NiCo2O4, Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, and mixtures thereof. In addition, the second catalyst layer may be formed of an electrode catalyst slurry including at least one selected from the group consisting of Ir, Pt, Au, Pd, Ag, Rh, Ru, Ni, Al, Mo, Cr, Cu, Ti, W, and mixtures thereof. More specifically, the electrode catalyst forming the first catalyst layer may be Pt, and the electrode catalyst forming the second catalyst layer may be Ir.

[0062] In addition, the catalyst can be used as a metal catalyst itself, or it can be used by being supported on a carrier. As the carrier, carbon-based materials such as graphite, Denka black, Ketjen black, acetylene black, carbon nanotubes, carbon nanofibers, or activated carbon can be used, or inorganic fine particles such as alumina, silica, zirconia, or titania can be used. In addition, the solvent for mixing or dissolving the catalyst can be an alcohol-based solvent such as water, methanol, ethanol, propanol, or isopropyl alcohol, an amide-based solvent such as N-methyl pyrrolidone or dimethylformamide, and a sulfoxide-based solvent such as dimethyl sulfoxide.

[0063]

[0064] According to one embodiment of the present invention, the thickness of the first carrier film and the second carrier film in steps (S1) and (S2) may be greater than 10 μm and less than or equal to 200 μm. For example, the thickness of the carrier film may be 11 µm or more, 20 µm or more, 25 µm or more, 30 µm or more, 40 µm or more, 50 µm or more, 55 µm or more, 58 µm or more, 60 µm or more, 70 µm or more, 80 µm or more, 90 µm or more, 200 µm or less, 190 µm or less, 180 µm or less, 170 µm or less, 160 µm or less, 150 µm or less, 140 µm or less, 130 µm or less, 120 µm or less, 110 µm or less, 100 µm or less, and specifically, may be 20 µm or more and 100 µm or less. When the first carrier film and the second carrier film satisfy the above thickness range, the effect of preventing a swelling phenomenon occurring in the separator is excellent, and the carrier film can be easily controlled during the coating process, thereby improving the work process.

[0065] According to one embodiment of the present invention, the first carrier film and the second carrier film may include at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene, tetrafluoroethylene-perfluoroalkylvinyl ether, ethylene / tetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyimide, polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, and polyester.

[0066] In addition, the adhesive may include at least one selected from the group consisting of acrylic resin, silicone resin, rubber resin, urethane resin, polyester resin, and epoxy resin. The adhesive may be coated on the surface of the carrier film, and the coating thickness may be 3 ㎛ or more and 10 ㎛ or less. For example, the coating thickness may be 3.0 ㎛ or more, 3.5 ㎛ or more, 4.0 ㎛ or more, 4.5 ㎛ or more, 4.5 ㎛ or more, 5.0 ㎛ or more, 5.5 ㎛ or more, 10.0 ㎛ or less, 9.5 ㎛ or less, 9.0 ㎛ or less, 8.5 ㎛ or less, or 8.0 ㎛ or less. When the coating thickness range of the adhesive is satisfied, an excellent level of adhesiveness can be achieved, and at the same time, the carrier film can be easily controlled, thereby improving the work processability.

[0067] Specifically, the carrier film of the present invention may comprise PET or PEN, and the adhesive may comprise acrylic, silicone, or urethane. When the carrier film and adhesive are used, damage and swelling of the separator can be effectively prevented, and the separator can be easily removed without damaging the adherend.

[0068] According to one embodiment of the present invention, the separation membrane may be a cation exchange membrane or an anion exchange membrane, and specifically, may be a cation exchange membrane. The separation membrane may be manufactured by dissolving cation / anion exchange resins in a solvent, or a commercially available cation / anion exchange membrane may be purchased and used.

[0069] For example, the cation exchange resin may be a polymer resin having at least one cation exchange group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a phosphonic acid group, and derivatives thereof in a side chain. Specific examples of the polymer resin may include a hydrogen ion conductive polymer selected from the group consisting of a fluorinated polymer, a benzimidazole polymer, a polyimide polymer, a polyetherimide polymer, a polysulfone polymer, a polyphenylene sulfide polymer, a polyether ketone polymer, copolymers thereof, and mixtures thereof, and preferably may include a film made of polyethylene terephthalate, polyimide, polyacrylonitrile, polyvinyl chloride, polytetrafluoroethylene, or polyurethane. In addition, the cation exchange membrane sold commercially may be a Nafion membrane.

[0070] In addition, the anion exchange resin, as an example, comprises a polymer backbone, i.e., a hydrophobic component that dominates the overall membrane properties, and an ion-conducting head group, i.e., a hydroxide ion (OH - ) may include a hydrophilic component involved in the transfer of ion-conducting head groups. The ion-conducting head groups may include cyclic ammonium derivatives such as piperidinium, pyrrolidinium, substituted imidazolium, and 6-azonia-spiro[5,5]undecane; and quaternary ammonium groups such as hexyltrimethyl ammonium. In addition, the polymer backbone may include at least one selected from the group consisting of polyphenylene oxide, polyetherketone, polyethersulfone, polybenzimidazole, polyphenylene, polyolefin, spirobisindene, and polynorbornene. In addition, the anion exchange membrane sold commercially may be a sustainer ion.

[0071] In addition, the thickness of the separator may be 10 ㎛ or more and 200 ㎛ or less. Specifically, the thickness of the separator may be 10 ㎛ or more, 30 ㎛ or more, 50 ㎛ or more, 90 ㎛ or more, 100 ㎛ or more, 125 ㎛ or more, 200 ㎛ or less, 180 ㎛ or less, 160 ㎛ or less, 150 ㎛ or less, 140 ㎛ or less, or 130 ㎛ or less. When the above thickness range is satisfied, the crossover phenomenon in which hydrogen moves through the separator can be suppressed, and since the swelling phenomenon of the separator and cracking of the electrode do not occur during direct coating, the performance of the electrolysis cell or stack can be improved.

[0072] According to one embodiment of the present invention, the membrane electrode assembly manufactured by the manufacturing method may be a membrane electrode assembly for water electrolysis. For example, the membrane electrode assembly may be included in a unit cell included in an electrochemical conversion device, and the electrochemical conversion device may include a fuel cell device, a device capable of producing useful chemical substances through electrochemical conversion such as water electrolysis, and a device capable of being utilized for reducing and converting carbon dioxide and NOx.

[0073] FIG. 1 is a process schematic diagram of a membrane electrode assembly of the present invention. For example, referring to FIG. 1, the process of the membrane electrode assembly manufacturing method may be performed in the following manner. A separator is supplied by a separator supply roller (100), and the separator may have a first carrier film (7) attached to one surface thereof. The supplied separator may be continuously moved toward the recovery roller (200) by the rotation of the supply roller (100), the recovery roller (200), and the support roller (500). Thereafter, an electrode catalyst slurry is provided through a first slot die (600), and a first catalyst layer may be coated on the other surface of the separator by the electrode catalyst slurry, and may be dried in a drying oven (800). Thereafter, a second carrier film may be supplied through a carrier film supply roller (300), and the second carrier film may be attached to the other surface of the separator on which the first catalyst layer is formed. Thereafter, the first carrier film can be recovered through the carrier film recovery roller (400). The separator, on which the first carrier film is recovered and the second carrier film is attached to the other surface of the separator coated with the first catalyst layer, can be continuously moved through the support roller (500). Thereafter, an electrode catalyst slurry is provided through the second slot die (700), and the second catalyst layer can be coated on one surface of the separator from which the first carrier film is recovered by the electrode catalyst slurry, and can be dried in a drying oven (800). Thereafter, the separator coated on both surfaces with the first catalyst layer and the second catalyst layer is recovered through the recovery roller (200), and then cut into a desired area size, thereby manufacturing a membrane electrode assembly.

[0074]

[0075] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0076]

[0077] <Example 1>

[0078] The anode catalyst composition is composed of 1 g of Ir catalyst and a commercial Nafion dispersion (Chemours nafion) as an ion-conducting binder resin. TM A catalyst composition was prepared by mixing 0.76 g of PFSA Polymer Dispersions D2020CS) and 1.94 g of 1-propanol (NPA) solvent.

[0079] The cathode catalyst composition is composed of 1 g of platinum catalyst (Pt / C) supported on carbon black and a commercial Nafion dispersion (Chemours nafion) as an ion-conducting binder resin. TM A catalyst composition was prepared by mixing 2 g of PFSA Polymer Dispersions D2020CS) and 7 g of 1-propanol (NPA) solvent.

[0080] Afterwards, Nafion film (Chemours nafion), a commercial product, was used as a separator. TM N115, 127 ㎛) was cut into a size of 160 mm × 130 mm, and then a first carrier film (PET 50 ㎛, urethane adhesive 8 ㎛) was attached to one side of the Nafion film without air bubbles using a roll laminator. Then, the cathode catalyst ink composition was coated on the other side of the Nafion film with a wet thickness of 100 ㎛ using a slot die method to form a first catalyst layer, and the separator on which the first catalyst layer was formed was dried at a temperature of 80° C. for 5 minutes. Thereafter, a second carrier film was attached to one side of the Nafion film, and the first carrier film was removed.

[0081] The second carrier film was manufactured by coating the same adhesive used in the first carrier film only on the area not corresponding to the first catalyst layer, and the second carrier film was bonded to one surface of the Nafion film in the same manner as the first carrier film and the separator were bonded.

[0082] Next, the anode catalyst ink composition was coated on one side of the Nafion film with a wet thickness of 50 μm using a slot die method to form a second catalyst layer. Thereafter, the separator on which the second catalyst layer was formed was dried at a temperature of 80° C. for 5 minutes, and then the second carrier film was removed, thereby manufacturing a membrane electrode assembly using a direct coating method.

[0083]

[0084] <Example 2>

[0085] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in Example 1, except that the entire area of ​​the second carrier film corresponding to the first catalyst layer was cut and removed, and then an adhesive was coated only on the area not corresponding to the first catalyst layer to manufacture the second carrier film.

[0086]

[0087] <Example 3>

[0088] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that a first carrier film and a second carrier film having a thickness of 25 μm were used.

[0089]

[0090] <Example 4>

[0091] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that a first carrier film and a second carrier film having a thickness of 100 μm were used.

[0092]

[0093] <Example 5>

[0094] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that a Nafion membrane (N212, 50 μm) was used.

[0095]

[0096] <Comparative Example 1>

[0097] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that the second carrier film was manufactured by coating the adhesive over the entire area of ​​the second carrier film.

[0098]

[0099] Comparative Example 2

[0100] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in Example 1 without using the first carrier film and the second carrier film. Specifically, the cathode catalyst composition and the anode catalyst composition were manufactured in the same manner as in Example 1. Thereafter, a commercial product, Nafion film (Chemours nafion) was used as a separator. TM N115, 127 ㎛) was cut into a size of 160 mm × 130 mm, and then the cathode catalyst ink composition was coated on the other side of the Nafion film with a wet thickness of 100 ㎛ using a slot die method to form a first catalyst layer, and the separator on which the first catalyst layer was formed was dried at a temperature of 80° C. for 5 minutes.

[0101] Thereafter, the anode catalyst ink composition was coated on one side of the Nafion film with a wet thickness of 50 μm using a slot die method to form a second catalyst layer. Thereafter, the separator on which the second catalyst layer was formed was dried at a temperature of 80° C. for 5 minutes to manufacture a membrane electrode assembly.

[0102]

[0103] <Comparative Example 3>

[0104] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that the first carrier film and the second carrier film having a PET thickness of 10 ㎛ were used.

[0105]

[0106] Comparative Example 4

[0107] In the above Example 1, a membrane electrode assembly was manufactured in the same manner as in the above Example 1, except that the first and second carrier films, each having a thickness of 25 μm and not coated with an adhesive, were attached to the Nafion film using electrostatic force.

[0108]

[0109] <Experimental Example>

[0110] It was visually confirmed whether a swelling phenomenon occurred in the membrane electrode assembly manufactured according to the above examples and comparative examples, and whether the catalyst layer was peeled off when the carrier film was removed during the manufacturing process. In addition, it was confirmed whether cracks occurred on the surface of the manufactured membrane electrode assembly, and the results are shown in Table 1 below. In addition, actual experimental photographs of the membrane electrode assembly and electrode surface of Example 1 are shown in FIG. 3, the membrane electrode assembly of Comparative Example 1 is shown in FIG. 4, and the actual experimental photographs of the membrane electrode assembly and electrode surface of Comparative Example 2 are shown in FIG. 5, respectively.

[0111]

[0112] Classification Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Separator membrane swelling phenomenon XXXXXXOOO Electrode crack occurrence XXXXX Catalyst layer peeling off OOO

[0113]

[0114] Referring to Table 1 above, in the case of membrane electrode assemblies manufactured using the direct coating method of the present invention and a carrier film satisfying the thickness range of the present invention, swelling, catalyst layer peeling, and surface electrode cracks did not occur. It can be confirmed that the manufacturing method of the present invention enables the manufacture of membrane electrode assemblies that improve work processability and productivity, reduce process costs, and enhance quality uniformity.

[0115] In contrast, in the case of Comparative Example 1 in which the entire area of ​​the second carrier film was coated with an adhesive, it was confirmed that the previously coated catalyst layer was peeled off, and in the case of Comparative Examples 2 to 4 in which no carrier film was used, or the thickness of the carrier film was outside the thickness range of the present invention, or was attached by electrostatic force, it was confirmed that the membrane swelling phenomenon occurred, and further, cracks occurred on the electrode surface.

[0116] In particular, when comparing FIG. 3 with FIG. 4 and FIG. 5, it can be confirmed that the membrane electrode assembly manufactured by Example 1 was manufactured without defects and without cracks on the electrode surface, whereas in the case of the membrane electrode assembly of Comparative Example 1, a portion of the catalyst layer was peeled off, and in the case of the membrane electrode assembly of Comparative Example 2, a swelling phenomenon occurred, causing the surface to be curved, and cracks occurred on the electrode surface, resulting in a significantly inferior quality.

[0117] 1: Membrane

[0118] 3: First catalyst layer

[0119] 5: Second catalyst layer

[0120] 7: First carrier film

[0121] 9: Second carrier film

[0122] 100: Membrane supply roller

[0123] 200: Recovery roller

[0124] 300: Carrier film supply roller

[0125] 400: Carrier film recovery roller

[0126] 500: Support roller

[0127] 600: 1st slot die

[0128] 700: 2nd slot die

[0129] 800: Drying oven

Claims

1. A step (S1) of forming a first catalyst layer on the other side of a separator having a first carrier film attached to one side; Step (S2) of attaching a second carrier film to the other surface of the separator on which the first catalyst layer is formed; Step (S3) of removing the first carrier film attached to one side of the separator; and A step (S4) of forming a second catalyst layer on one surface of the separator from which the first carrier film has been removed is included. The second carrier film includes a first region corresponding to the first catalyst layer among the other surfaces of the separator and a second region which is the remaining region excluding the first region. A method for manufacturing a membrane electrode assembly, wherein an adhesive is coated on the surface facing the other surface of the separator on which the first catalyst layer is formed in the second region of the second carrier film.

2. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the first region does not contain the adhesive.

3. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the second carrier film is formed only by the second region.

4. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the first catalyst layer and the second catalyst layer of the above step (S1) and the above step (S4) are each independently formed by coating the electrode catalyst slurry on the separator and then drying it.

5. In claim 4, A method for manufacturing a membrane electrode assembly, wherein the coating is performed by at least one method selected from the group consisting of a slot die method, an inkjet coating method, a spray coating method, a screen printing method, a doctor blade method, and a gravure coating method.

6. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the thicknesses of the first carrier film and the second carrier film in the above (S1) and (S2) steps are each independently greater than 10 ㎛ and less than or equal to 200 ㎛.

7. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the first carrier film and the second carrier film each independently include at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene, tetrafluoroethylene-perfluoroalkylvinyl ether, ethylene / tetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyester.

8. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the adhesive comprises at least one selected from the group consisting of acrylic resin, silicone resin, rubber resin, urethane resin, polyester resin, and epoxy resin.

9. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the above-mentioned membrane is a cation exchange membrane or an anion exchange membrane.

10. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the first catalyst layer is formed of an electrode catalyst slurry comprising at least one selected from the group consisting of Pt, Sn, Al, Au, Ag, C, Cd, Co, Cr, Cu, Ga, Hg, In, Mo, Nb, Ni, NiCo2O4, Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, and mixtures thereof.

11. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the second catalyst layer is formed of an electrode catalyst slurry comprising at least one selected from the group consisting of Ir, Pt, Au, Pd, Ag, Rh, Ru, Ni, Al, Mo, Cr, Cu, Ti, W, and mixtures thereof.

12. In claim 1, A method for manufacturing a membrane electrode assembly, wherein the above membrane electrode assembly is a membrane electrode assembly for water electrolysis.

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