Electrode for fuel cell with prevented ionomer poisoning of the catalyst and reduced elution, and method for its production

Abstract

An electrode for a fuel cell comprises an electrode binder and an electrode catalyst dispersed therein. The electrode catalyst consists of a catalyst complex with a catalytic metal deposited on a support and a porous polymer coating layer. The porous polymer enhances performance by forming a core-shell structure on the surface of the catalytic metal. A process for manufacturing the electrode includes preparing the catalyst complex, coating the catalytic metal with the porous polymer to form an electrode catalyst, combining the catalyst with an electrode binder to create a slurry, and applying the slurry to a substrate. The porous polymer is optionally an intrinsically microporous (PIM) polymer or a copolymer whose molecular weight, composition, and thickness are optimized for conductivity and performance.The electrode is suitable for use in a membrane electrode arrangement for fuel cells.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an electrode for a fuel cell and a method for producing it, wherein a coating layer of an electrode catalyst with a core-shell structure contains a porous polymer, thereby preventing ionomer poisoning of the catalyst and reducing elution. BACKGROUND

[0002] A proton exchange membrane fuel cell (PEMFC or polymer electrolyte membrane fuel cell) is a power generation device that uses hydrogen as fuel and offers advantages such as high energy efficiency, simple system configuration, and environmental friendliness. Proton exchange membrane fuel cells have recently gained attention as energy conversion devices for environmentally friendly automobiles.

[0003] The power-generating reaction in a fuel cell takes place in a membrane electrode assembly (MEA), which includes a perfluorinated sulfonic acid (PFSA) membrane and anode / cathode electrodes. When hydrogen is supplied to the anode, the oxidation electrode of the fuel cell, it is split into protons and electrons. The protons move through a membrane to the cathode, which is the reduction electrode, and the electrons move to the cathode via an external circuit. At the cathode, oxygen molecules, protons, and electrons combine to generate electricity and heat, with water (H₂O) as a byproduct of the reaction.

[0004] The performance of fuel cells is significantly impaired by the high overvoltage (up to 300-400 mV) of the oxygen reduction reaction (ORR) at the cathode. Current research and development of fuel cell catalysts focuses primarily on improving the specific activity of platinum catalysts, etc., on carbon supports. However, a critical issue is that platinum nanoparticles (NPs) are susceptible to activity degradation in harsh electrochemical environments, including poisoning by ionomers present in the electrode. SUMMARY

[0005] The present disclosure was made taking into account the problems encountered in the prior art, and one objective of the present disclosure is to provide an electrode for a fuel cell which is able to effectively protect a catalytic metal from a catalyst poisoning agent in an oxidizing electrochemical environment by applying a predetermined shell or coating layer to the surface of the catalytic metal.

[0006] A further objective of the present disclosure is to provide an electrode catalyst capable of maintaining high oxygen permeability and proton transport capacity by controlling the material, oxygen permeability, thickness, etc., of the coating layer, as well as an electrode for a fuel cell containing the electrode catalyst. A further objective of the present disclosure is to provide a method for the simpler fabrication of an electrode for a fuel cell containing the catalyst with such a structure.

[0007] The objectives of this disclosure are not limited to the foregoing. The objectives of this disclosure can be clearly understood from the following description and can be achieved by the means and combinations thereof described in the claims.

[0008] In one aspect, an electrode for a fuel cell is provided, comprising a) an electrode binder and b) an electrode catalyst mixed with the electrode binder, wherein the electrode catalyst comprises a catalyst complex comprising a catalytic metal applied to a support and a coating layer comprising a porous polymer on at least a part of the surface of the catalytic metal.

[0009] One embodiment of the present disclosure provides an electrode for a fuel cell which includes an electrode binder and an electrode catalyst dispersed in the electrode binder, wherein the electrode catalyst comprises a catalyst complex comprising a catalytic metal applied on a support and a coating layer formed by coating at least a part of the surface of the catalytic metal with a porous polymer.

[0010] In one embodiment, the electrode binder can contain a perfluorinated sulfonic acid polymer.

[0011] In one embodiment, the catalytic metal may comprise one or more of platinum, palladium, cobalt, gold, ruthenium, tin, molybdenum, rhodium, iridium, bismuth, copper, yttrium and chromium.

[0012] In one embodiment, the support may comprise a carbon-based support, and the carbon-based support may comprise one or more of carbon black, carbon nanotubes, graphite, and graphene.

[0013] In one embodiment, the porous polymer can contain a polymer with intrinsic microporosity (PIM).

[0014] The porous polymer may also contain a copolymer of one of the monomers A1 to A18 listed below and one of the monomers B1 to B19 listed below.

[0015] Here, Ha can contain one or more of the elements F, Cl, Br and I.

[0016] In one embodiment, the porous polymer can be represented by the chemical formula 1 below.

[0017] Here, X includes one or more of: and and n is an integer from 1 to 10.

[0018] In one embodiment, the coating layer can contain a porous polymer with a number-average molecular weight (Mn) of 5,000 to 100,000.

[0019] In one embodiment, the weight ratio between the catalyst complex and the porous polymer in the coating layer can be 100:3 to 100:20.

[0020] In one embodiment, the thickness of the coating layer can range from 0.1 nm to 5 nm.

[0021] Another embodiment of the present disclosure provides a membrane electrode arrangement comprising an electrolyte membrane, a cathode formed on one side of the electrolyte membrane and an anode formed on the other side of the electrolyte membrane, wherein at least one of the cathode and the anode contains the electrode described above.

[0022] Another embodiment of the present disclosure provides a method for producing an electrode for a fuel cell, comprising the production of a catalyst complex containing a support, a catalytic metal and a porous polymer, the production of an electrode catalyst with a core-shell structure by coating at least a part of the surface of the catalytic metal with the porous polymer, the production of a slurry by combining the electrode catalyst with an electrode binder and the formation of an electrode by applying the slurry to a substrate.

[0023] In this case, the preparation of the electrode catalyst can include adding the catalyst complex and the porous polymer to a solvent, followed by mixing, precipitation, and recovery of the electrode catalyst by pouring an aqueous solvent into the mixture and drying the recovered electrode catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features of the present disclosure are now described in detail with reference to certain exemplary embodiments thereof in the accompanying drawings, which are shown below for illustrative purposes only and are therefore not limiting to the present disclosure, and wherein: Fig. Figure 1 shows a part of an electrode according to the present disclosure; Fig. Figure 2 shows a membrane electrode arrangement according to the present disclosure; Fig.Figure 3 shows a transmission electron micrograph of an electrode catalyst according to manufacturing example 1; Fig. Figure 4 shows a transmission electron micrograph of an electrode catalyst according to manufacturing example 2; Fig. Figure 5 shows a transmission electron micrograph of an electrode catalyst according to manufacturing example 3; Fig. Figure 6 shows part of the image of Fig. 3, in which energy-dispersive spectroscopy (EDS) is performed, and a magnified view of it; Fig. Figure 7 shows the results of a line scan of the [unclear text]. Fig. 6. Part shown using energy-dispersive spectroscopy (EDS); Fig. Figure 8 shows the results of the BOL and EOL performance of a membrane electrode arrangement according to Example 1; and Fig.Figure 9 shows the results of BOL, EOL 10K and EOL 50K of a membrane electrode arrangement according to Example 2. DETAILED DESCRIPTION OF CERTAIN VERSIONS

[0025] The above and other objectives, features, and advantages of the present disclosure will be better understood with reference to the following preferred embodiments in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein and can be modified in various ways. These embodiments are provided to thoroughly explain the disclosure and to adequately convey the concept of the present disclosure to those skilled in the art.

[0026] In the drawings, the same reference numerals refer to identical or similar elements. For the clarity of this disclosure, the dimensions of the structures are shown larger than their actual sizes. It is understood that, although terms such as "first," "second," etc., may be used here to describe different elements, these elements are not intended to be restricted by these terms. These terms are used only to distinguish one element from another. For example, a "first" element discussed below could be called a "second" element without this deviating from the scope of this disclosure. Similarly, the "second" element could also be called a "first" element. The singular forms used here also include the plural forms, unless the context clearly indicates otherwise.

[0027] It is further understood that the terms "include," "contain," "have," etc., when used in this description, indicate the presence of certain features, integers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. When an element such as a layer, film, surface, or sheet is described as being "on" another element, it may be located directly on top of the other element, or there may be elements in between. When an element such as a layer, film, surface, or sheet is described as being "under" another element, it may be located directly beneath the other element, or there may be elements in between.

[0028] The terminology used herein serves only to describe certain embodiments and is not to be construed as limiting the disclosure. The singular forms "a" and "the" used herein also include the plural forms unless the context clearly indicates otherwise. These terms serve only to distinguish one component from another and do not restrict the nature, sequence, or arrangement of the individual components. As used herein, the term "and / or" includes all combinations of one or more of the listed components. Furthermore, the terms "unit," "-ers," "-or," and "module" used in the description denote units for processing at least one function and operation and may be implemented by hardware components or software components and combinations thereof.

[0029] Although the exemplary embodiment is described with a plurality of units for carrying out the exemplary method, it is understood that the exemplary methods can also be carried out by one or more modules. Furthermore, it is understood that the term control unit refers to a hardware device comprising memory and a processor, specifically programmed to execute the methods described herein. The memory is configured to store the modules, and the processor is configured to execute the modules to perform one or more of the methods described below.

[0030] Furthermore, the control logic of the present disclosure can be embodied as a non-transitory computer-readable medium on a computer-readable medium containing executable program instructions that are executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable medium can also be distributed across networked computer systems, such that the computer-readable medium is stored and executed in a distributed manner, for example, by a telematics server or a controller area network (CAN).

[0031] Unless explicitly stated or evident from the context, the term "approximately" is used here to mean within a normal tolerance range, e.g., within two standard deviations of the mean. "Approximately" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise indicated by the context, all numerical values ​​given herein are modified by the term "approximately".

[0032] Unless otherwise stated, all numbers, values, and / or representations expressing the amounts of components, reaction conditions, polymer compositions, and mixtures used herein are to be understood as approximate values, including various measurement uncertainties that arise, among other things, in obtaining these values, and should therefore be modified in all cases by the term "approximately." Where a numerical range is given in this description, it is continuous and includes all values ​​from the minimum value of the range to its maximum value, unless otherwise stated. Furthermore, where such a range refers to integer values, all integer values, including the minimum value up to the maximum value, are included, unless otherwise stated.

[0033] If a range for a variable is described in the present description, it should be assumed that the variable includes all values, including the described endpoints, within the specified range. For example, the range "5 to 10" includes all subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., as well as individual values ​​of 5, 6, 7, 8, 9, and 10, and also includes all values ​​between valid integers within the specified range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc. The range "10% to 30%", for example, includes subranges such as 10% to 15%, 12% to 18%, 20% to 30%, etc., as well as all integers with values ​​from 10%, 11%, 12%, 13%, etc., up to 30%, and also includes every value between valid integers within the specified range, such as 10.5%, 15.5%, 25.5%, etc.

[0034] Fig.Figure 1 shows a portion of an electrode according to the present disclosure. An electrode for a fuel cell according to an embodiment of the present disclosure comprises an electrode binder 100 and an electrode catalyst 200 dispersed in the electrode binder 100. In the electrode for a fuel cell, the electrode catalyst 200 can comprise a catalyst complex 210 with a catalytic metal 212 applied to a support 211 and a coating layer 220 formed by coating at least a portion of the surface of the catalytic metal 212 with a porous polymer. In particular, the electrode catalyst can be configured such that a core-shell catalyst with a core containing a catalytic metal 212 and a shell 220, in which at least a portion of the surface of the catalytic metal 212 is coated with a porous polymer, is applied to the support 211.

[0035] In the present disclosure, it is possible to prevent the catalytic metal 212 from being poisoned by an ionomer by increasing the hydrophobicity through a core-shell structure in which the surface of the catalytic metal 212 is coated with a porous polymer, and it is possible to drastically reduce the degradation of the catalytic performance by elution of the catalytic metal 212, such as platinum, outside the electrode.

[0036] In one embodiment, the electrode binder 100 can contain a perfluorinated sulfonic acid polymer, for example Nafion.

[0037] In one embodiment, the catalytic metal 212 can comprise one selected from platinum, palladium, cobalt, gold, ruthenium, tin, molybdenum, rhodium, iridium, bismuth, copper, yttrium, chromium, and combinations thereof. Here, "combination" means an alloy of metallic elements. Platinum or a platinum alloy is preferably used as the catalytic metal 212.

[0038] In one embodiment, the catalyst complex can comprise a support 211 and a catalytic metal 212 applied to the support 211, as shown in Fig. Figure 1 shows the support 211. The support can play a role in increasing the active area of ​​the catalytic metal 212 and improving its stability by carrying the catalytic metal 212 on its surface.

[0039] The support 211 is not particularly restricted as long as it is commonly used in the industry and can, for example, be a carbon-based support. The carbon-based support can be selected from a group consisting of carbon black, carbon nanotubes, graphite, graphene, and combinations thereof. The carbon black can include acetylene black, Denka black, Ketjen black, etc.

[0040] When the catalyst complex in which the catalytic metal 212 is applied to the support 211 is used as the electrode catalyst, a coating layer 220 can be formed by coating the surface of the catalytic metal 212 with the porous polymer. This may be due to the fact that functional groups such as -CN groups, etc., contained in the porous polymer have an electron-withdrawing effect and, as a result of this effect, preferentially bind to the relatively electron-rich catalytic metal 212.

[0041] In one embodiment, the porous polymer can contain a polymer with intrinsic microporosity (PIM). It is known that PIMs consist of rigid and highly distorted polymer backbones, which hinder the formation of a densely packed structure in the solid state and, due to inefficient stacking, form micropores in an amorphous structure. Accordingly, PIMs have high oxygen permeability and a high fractional free volume.

[0042] Furthermore, although not an ionomer, a PIM can exhibit adequate proton conductivity by transporting protons along with an aqueous solvent such as water in its intrinsic micropores.

[0043] The electrode catalyst 200 according to the present disclosure has a core-shell structure formed by coating the surface of the catalytic metal 212 with a PIM, thereby effectively protecting the catalytic metal 212 from catalyst poisoning in an oxidizing electrochemical environment and also maintaining high oxygen permeability and proton transport capacity through the coating layer 220. Furthermore, the PIM has a high affinity for the catalytic metal 212, such as platinum, etc., and can therefore be uniformly applied to the surface of the catalytic metal 212.

[0044] As a non-restrictive example, the PIM according to the present disclosure can be represented by the chemical formula 1 below.

[0045] Here, X includes at least one element of: and and n is an integer from 1 to 10 or an integer from 6 to 7.

[0046] Furthermore, according to the present disclosure, the PIM type may contain a copolymer of at least one of the following monomers A1 to A18 and at least one of the following monomers B1 to B19. [Monomers A1 to A18] [Monomers B1 to B19]

[0047] Here, Ha can contain at least one halogen element selected from the group consisting of F, Cl, Br and I.

[0048] Preferably, the PIM is produced by condensation polymerization of monomer A, represented by chemical formula 2 below, and monomer B, represented by chemical formula 3 below.

[0049] Monomer A can be represented by the chemical formula 2 below.

[0050] Here, A can comprise at least one of: and

[0051] Monomer B can be represented by the chemical formula 3 below.

[0052] Here, Ha can contain at least one halogen element selected from the group consisting of F, Cl, Br and I.

[0053] The condensation reaction of monomers A and B can be carried out according to a generally known procedure and is not particularly restricted.

[0054] In one embodiment, the coating layer 220 can contain a porous polymer with a number-average molecular weight (Mn) of 5,000 to 100,000 g / mol. If the number-average molecular weight of the porous polymer is below 5,000, its mobility may become too high, making it difficult to properly fix the porous polymer to the surface of the catalyst. Conversely, if the number-average molecular weight of the porous polymer exceeds 100,000, the permeability to materials such as water, oxygen, and protons may decrease, and the activity of the catalyst may deteriorate. Preferably, the number-average molecular weight of the porous polymer is between 5,000 and 55,000 g / mol.

[0055] In one embodiment, the weight ratio between the catalyst complex and the porous polymer in the coating layer 220 can be between 100:3 and 100:20. If the weight ratio between the catalyst complex and the porous polymer is less than 100:3, the amount of porous polymer relative to the catalyst complex may be too small, so that the porous polymer may not be properly deposited onto the surface of the catalytic metal 212. Conversely, if the weight ratio of the catalyst complex to the porous polymer in the coating layer 220 exceeds 100:20, the porous polymer may even be deposited onto the surface of the support 211 beyond the surface of the catalytic metal 212 in the catalyst complex. In this case, the activity of the catalyst complex may be impaired.

[0056] In one embodiment, the thickness of the coating layer 220 can range from 0.1 nm to 5 nm. If the thickness of the coating layer 220 is less than 0.1 nm, the amount of porous polymer coating the catalytic metal 212 may be too small, so that the effects of preventing ionomer poisoning and increasing catalytic activity may not be fully realized. Conversely, if the thickness of the coating layer 220 exceeds 5 nm, the permeability to materials such as water, oxygen, and protons may decrease, and the catalyst activity may deteriorate.

[0057] Fig.Figure 2 shows a membrane electrode arrangement according to the present disclosure. A membrane electrode arrangement according to another embodiment of the present disclosure may comprise an electrolyte membrane 30, a cathode 10 formed on one side of the electrolyte membrane 30, and an anode 20 formed on the other side of the electrolyte membrane 30, and at least one of the cathode 10 or the anode 20 may comprise the electrode described above.

[0058] The anode 20 is an electrode that accepts a fuel such as hydrogen gas to split hydrogen into protons and electrons through a hydrogen oxidation reaction (HOR), and is also referred to as a fuel electrode.

[0059] At the cathode 10, current and heat are generated by the oxygen reduction reaction (ORR) of protons moving from the anode 20 through the electrolyte membrane 30, of electrons supplied from an external circuit, and of oxygen gas supplied from the outside, and water is simultaneously produced as a reaction by-product.

[0060] In the membrane electrode arrangement according to the present disclosure, the electrode according to the present disclosure can be used as anode 20 and / or cathode 10, thereby obtaining a fuel cell with excellent electrochemical performance and durability.

[0061] Furthermore, the electrolyte membrane 30 can be used without special restrictions, provided it is standard practice in the industry. For example, a polymer (ionomer) with proton conductivity, such as Nafion, can be used. An electrolyte membrane 30 can also be used in which a reinforced membrane, such as e-PTFE (expanded polytetrafluoroethylene), is impregnated with the ionomer.

[0062] A process for producing an electrode for a fuel cell according to the present disclosure may include the production of a catalyst complex comprising a support 211 and a catalytic metal 212 and a porous polymer, the production of an electrode catalyst with a core-shell structure by coating at least a part of the surface of the catalytic metal 212 with the porous polymer, the production of a slurry by adding the electrode catalyst to an electrode binder, and the formation of an electrode by applying the slurry to a substrate.

[0063] The porous polymer can be prepared by condensation polymerization of at least one of the monomers A1 to A18 (monomer group A) and at least one of the monomers B1 to B19 (monomer group B) as described above. Preferably, the porous polymer is prepared by condensation polymerization of monomer A, represented by chemical formula 2, and monomer B, represented by chemical formula 3. The condensation reaction between monomer group A and monomer group B can be carried out according to a conventionally known method and is not particularly restricted.

[0064] The porous polymer can be obtained, for example, by mixing monomer group A, monomer group B and potassium carbonate (K2CO3) while stirring.

[0065] Specifically, monomer group A, monomer group B, and potassium carbonate (K₂CO₃) are placed in a round-bottom flask, a reflux condenser is connected, and the flask is filled with nitrogen or argon. The mixture is heated at 140–180°C for 0.5–8 hours with stirring. After the reaction is complete, the temperature is lowered to 25°C, and the mixture is then precipitated in an organic solvent, including methanol or ethanol. This precipitation is repeated 1–3 times with the same organic solvent, followed by drying in a vacuum oven at 60–100°C for 20–28 hours, yielding a polymer with intrinsic microporosity (PIM).

[0066] In one embodiment, the production of the electrode catalyst 200 may include the addition of the catalyst complex and the porous polymer to a solvent and the subsequent mixing, precipitation and recovery of the electrode catalyst 200 by pouring an aqueous solvent into the mixture and drying the recovered electrode catalyst 200.

[0067] Unless otherwise described herein, the structure, composition, quantity and the like of the porous polymer, the electrode catalyst 200, etc. are essentially the same as described above, so a description thereof is omitted.

[0068] A better understanding of the present disclosure can be gained through the following examples and comparisons. However, these examples are not to be understood as limiting the technical idea of ​​the present disclosure. Production example - Production of an electrode catalyst Production example 1 - 10 g Pt / C + 1 g PIM-1(C)

[0069] An intrinsically microporous polymer (PIM-1) was prepared by the following reaction scheme, namely by adding 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethylspirobisindane (TTSBI), 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN), and potassium carbonate (K₂CO₃) to dimethylformamide (DMF) under stirring. Here, the condensation reaction between SBI and TFTPN was carried out according to a conventionally known procedure.

[0070] PIM-1(C) was thus produced by adjusting the repeating unit m of the formula so that the number-mean molecular weight (Mn) is approximately 15,000 g / mol.

[0071] A mixture was prepared by adding 1 g of the PIM-1(C) prepared above and 10 g of a Pt / C catalyst complex, in which a platinum catalyst is applied to a carbon support, to N-methylpyrrolidone (NMP) as the organic solvent. The mixture was then placed in a bead mill and milled at 500 rpm for 2 hours, coating the surface of the platinum catalyst with the porous polymer.

[0072] Water was added to the mixture in which the electrode catalyst was dispersed to precipitate the catalyst, and the mixture was then centrifuged to recover it. The recovered electrode catalyst was then dried in a vacuum oven, yielding an electrode catalyst according to Preparation Example 1. Production example 2 - 10 g Pt / C + 2 g PIM-1(A)

[0073] An electrode catalyst with a core-shell structure according to Preparation Example 2 was prepared in the same manner as in Preparation Example 1, except that PIM-1(A) with a number-mean molecular weight (Mn) of about 50,000 g / mol was prepared as a polymer with intrinsic microporosity and added in an amount of 2 g to NMP as an organic solvent. Production example: 3 - 10 g Pt / C + 1 g PIM-1(A)

[0074] An electrode catalyst with a core-shell structure according to Preparation Example 3 was prepared in the same way as in Preparation Example 2, except that 1 g of PIM-1(A) was added to NMP as an organic solvent.

[0075] The actual number-mean molecular weight (Mn), weight-mean molecular weight (Mw) and polydispersity index (PDI) of PIM-1(A) and PIM-1(C) synthesized in Production Examples 1 to 3 are listed in Table 1 below. [Table 1] Mn (g / mol) Mw (g / mol) PDI PIM-1 (A) 15028 31409 2.09 PIM-1 (C) 52848 87556 1.66 Test example 1

[0076] To confirm the structure and composition of the prepared electrode catalysts, the electrode catalysts were analyzed using a transmission electron microscope (TEM) according to preparation examples 1 to 3. The corresponding results are presented in the Fig. 3 to 5 are shown.

[0077] With reference to Fig. 3 to 5, all electrode catalysts synthesized by the process according to the present disclosure exhibited a core-shell structure. The thickness of the coating layer was also determined and is approximately 0.1 nm to 5 nm.

[0078] To confirm the composition of the metal catalyst and the coating layer formed on its surface, the electrode catalyst was analyzed according to Preparation Example 1 using energy-dispersive spectroscopy (EDS), as described in Fig. 6 shown, scanned line by line, and the results are in Fig. 7 shown.

[0079] Referring to the results in Fig. Nitrogen and fluorine were detected in 7. It is assumed that this originates from the -CN group and the -F group in PIM-1(C). Therefore, it was confirmed that the coating layer of the electrode catalyst, which was produced according to the present disclosure, contains the porous polymer. Example - Fabrication of a membrane electrode assembly Example 1 - Use of fabrication example 1

[0080] An electrode slurry was prepared by adding the electrode catalyst according to Preparation Example 1 and Nafion (D2021) as an electrode binder to a solvent mixture of 100 g NPA (n-propyl alcohol) and 100 g water. The weight ratio of the electrode catalyst to the electrode binder was adjusted so that the weight of the carbon support in the electrode catalyst and the weight of the Nafion were 1:1.

[0081] Furthermore, an anode slurry was prepared by adding a Pt / C catalyst and Nafion (D2021) as an electrode binder to the solvent mixture. The weight ratio of the Pt / C catalyst to the electrode binder was adjusted so that the weight of the carbon support of the Pt / C catalyst and the weight of the Nafion were 1:1.

[0082] The electrode slurry was applied to one side of known Nafion (211) as the electrolyte membrane, and the anode slurry was applied to the other side, followed by drying and heat treatment, thereby producing a membrane-electrode assembly comprising a cathode (the electrode slurry), an anode, and an intermediate electrolyte membrane. The catalyst loading at the cathode was set to 0.4 mg Pt / cm 2 and the catalyst loading at the anode to 0.05 mg Pt / cm 2 set. Example 2 - Use of manufacturing example 2

[0083] A membrane electrode assembly was fabricated in the same manner as in Example 1, except that the electrode catalyst used in the fabrication of the membrane electrode assembly was determined according to Fabrication Example 2, and the catalyst loading on the cathode was set to 0.15 mg. Pt / cm 2was discontinued. Comparative example - use of a known Pt / C catalyst

[0084] A membrane electrode arrangement was prepared in the same manner as in Example 1, except that in the preparation of the electrode slurry for use in a cathode, a known Pt / C catalyst which does not contain a porous polymer was used instead of the electrode catalyst according to Preparation Example 1. Test example 2 - Verification of the electrochemical performance of the membrane electrode assembly

[0085] To verify the performance of the membrane electrode assemblies according to Example 1, Example 2 and Comparative Example, a unit cell was fabricated by mounting the fabricated membrane electrode assembly at a pressure of 100 in*lb using a Teflon gasket and a carbon bipolar plate, after which an accelerated degradation test (ADT) was performed under the following conditions.

[0086] The ADT conditions were 0.6 V - 0.95 V square wave, 3 seconds, 10,000 times; ambient conditions: RH 100%, 80°C, 3.0 bar a , AN: Hydrogen 42 sccm, CA: Nitrogen 134 sccm.

[0087] The results of Example 1 are shown in Table 2 and Fig. 8, the results of comparison example 1 are shown in Table 3. [Table 2] Current density (A / cm²) 80°C, RH20%, 3,0 Bar a BOL (beginning of life) EOL (end of life) Performance degradation rate 0.08 0.865 V 0.857 V 0.96% 1.0 0.703 V 0.697 V 0.95% 2.0 0.567 V 0.548 V 3.45% 3.0 0.374 V 0.311 V 16.83% [Table 3] Current density (A / cm²) 80°C, RH20%, 3,0 Bar a BOL (beginning of life) EOL (end of life) Performance degradation rate 0.08 0.864 V 0.829 V 4.05% 1.0 0.669 V 0.616 V 7.92% 2.0 0.524 V 0.443 V 15.45% 3.0 - - -

[0088] Tables 2 and 3 show that Example 1, in which the electrode catalyst with the porous polymer coating layer according to the present disclosure was used as the electrode, had a much lower power degradation rate than the comparison example.

[0089] Furthermore, the accelerated degradation of the unit cell test was also performed on Example 2 under the following conditions. The results are shown in Table 4 below and in Fig. 9 shown.

[0090] The conditions for ADT are 0.6 V - 0.95 V square wave, 3 seconds, 10,000 times and 50,000 times; ambient conditions: RH 100%, 60°C, 2.5 bar a , AN: Hydrogen 42 sccm, CA: Nitrogen 134 sccm. [Table 4] Current density (A / cm²) 60°C, 50% RH, 2.0 Bar a BOL EOL (10K) Performance degradation rate EOL (50K) Performance degradation rate 0.08 0.898 V 0.876 V 2.45% 0.849 5.46% 1.0 0.733 V 0.718 V 2.05% 0.688 6.14% 2.0 0.550 V 0.548 V 0.36% 0.477 13.27% 3.0 - - -

[0091] Referring to the results of Table 4 and Fig.Example 2 showed a low performance degradation rate of 3% or less, even when the accelerated degradation test was repeated 10,000 times. Even when the accelerated degradation test in Example 2 was repeated 50,000 times, the performance degradation rate was similar to that of comparison Example 1, in which such a test was repeated only 10,000 times.

[0092] As can be seen from the foregoing, an electrode for a fuel cell according to the present disclosure can effectively protect a catalyst from a catalyst poisoning agent in an oxidizing electrochemical environment, due to the use of an electrode catalyst comprising a catalyst complex with a catalytic metal applied to a support and a coating layer formed by coating at least a part of the surface of the catalytic metal with a porous polymer.

[0093] Furthermore, the porous polymer allows for high oxygen permeability and proton transport capacity. In addition, the porous polymer has a high affinity for the catalytic metal of the core and can be uniformly applied to the surface of the catalytic metal.

[0094] Furthermore, a method for manufacturing an electrode for a fuel cell according to the present disclosure enables the uniform coating of the surface of a catalytic metal with a coating layer containing the porous polymer without carrying out a separate air etching process, etc.

[0095] The effects of this revelation are not limited to the foregoing. It is to be assumed that the effects of this revelation include all effects that can be derived from the description of this revelation.

[0096] Since the embodiments of the present disclosure have been described above, the person skilled in the art will recognize that various modifications and changes are possible by altering, deleting or adding components without deviating from the scope and idea of ​​the present disclosure as described in the attached claims, which are also deemed to be included in the scope of protection of the present disclosure.

Claims

[1] Electrode for a fuel cell, wherein the electrode comprises: an electrode binder; and an electrode catalyst mixed with the electrode binder, the electrode catalyst comprises: a catalyst complex containing a catalytic metal applied to a support; and a coating layer of a porous polymer on at least part of the surface of the catalytic metal. [2] Electrode according to claim 1, wherein the electrode binder comprises a perfluorinated sulfonic acid polymer. [3] Electrode according to claim 1 or 2, wherein the catalytic metal comprises one or more of platinum, palladium, cobalt, gold, ruthenium, tin, molybdenum, rhodium, iridium, bismuth, copper, yttrium and chromium. [4] Electrode according to at least one of claims 1-3, wherein the support comprises a carbon-based support and the carbon-based support comprises one or more of carbon black, carbon nanotubes, graphite and graphene. [5] Electrode according to at least one of claims 1-4, wherein the porous polymer comprises a polymer with intrinsic microporosity (PIM). [6] Electrode according to at least one of claims 1-5, wherein the porous polymer comprises a copolymer of any one of the following monomers A1 to A18 and any one of the following monomers B1 to B19: [Monomers A1 to A18] and; [Monomers B1 to B19] wherein Ha comprises one or more of F, Cl, Br and I. [7] Electrode according to at least one of claims 1-6, wherein the porous polymer is represented by the chemical formula 1 below: where X includes one or more of: and and n is an integer from 1 to 10. [8] Electrode according to at least one of claims 1-7, wherein the coating layer comprises a porous polymer having a number-average molecular weight (Mn) of about 5,000 to 100,000. [9] Electrode according to at least one of claims 1-8, wherein the weight ratio between the catalyst complex and the porous polymer in the coating layer is about 100:3 to 100:

20. [10] Electrode according to at least one of claims 1-9, wherein the thickness of the coating layer is about 0.1 nm to 5 nm. [11] Membrane electrode arrangement comprising: an electrolyte membrane; a cathode formed on one side of the electrolyte membrane; and an anode formed on the other side of the electrolyte membrane, wherein at least one of the cathode and anode comprises the electrode according to at least one of claims 1-10. [12] Method for manufacturing an electrode for a fuel cell, the method comprising: Production of a catalyst complex comprising a support, a catalytic metal and a porous polymer; Producing an electrode catalyst with a core-shell structure by coating at least part of the surface of the catalytic metal with the porous polymer; Producing a slurry by combining the electrode catalyst with an electrode binder; and Forming an electrode by applying the slurry to a substrate. [13] Method according to claim 12, wherein the production of the electrode catalyst comprises: Adding the catalyst complex and the porous polymer to a solvent and then mixing; Precipitation and recovery of the electrode catalyst by pouring an aqueous solvent into a mixture; and Drying of the recovered electrode catalyst. [14] Method according to claim 12 or 13, wherein the catalytic metal comprises one or more of platinum, palladium, cobalt, gold, ruthenium, tin, molybdenum, rhodium, iridium, bismuth, copper, yttrium and chromium and combinations thereof. [15] Method according to at least one of claims 12-14, wherein the porous polymer comprises a polymer with intrinsic microporosity (PIM). [16] Method according to at least one of claims 12-15, wherein the porous polymer comprises a copolymer of at least one of the following monomers A1 to A18 and at least one of the following monomers B1 to B19: [Monomers A1 to A18] and [Monomers B1 to B19] wherein Ha comprises one or more of F, Cl, Br and I. [17] Method according to at least one of claims 12-16, wherein the porous polymer is represented by the chemical formula 1 below: [Chemical Formula 1] where X comprises one or more of: and n is an integer from 1 to 10. [18] Method according to at least one of claims 12-17, wherein the coating layer comprises a porous polymer having a number-average molecular weight (Mn) of about 5,000 to 100,000. [19] Method according to at least one of claims 12-18, wherein the weight ratio between the catalyst complex and the porous polymer is about 100:3 to 100:

20. [20] Method according to at least one of claims 12-19, wherein the thickness of the coating layer is about 0.1 nm to 5 nm.

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