Polymer electrolyte membrane, method for manufacturing same, and membrane-electrode assembly, water electrolysis cell and fuel cell comprising same
A polymer electrolyte membrane with a cation conductor and phosphate ester crosslinks improves conductivity and stability, addressing moisture sensitivity issues and enhancing performance in humidified environments for water electrolysis and fuel cells.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KOLON INDUSTRIES INC
- Filing Date
- 2025-05-09
- Publication Date
- 2026-06-25
AI Technical Summary
Existing polymer electrolyte membranes with sulfonic acid side chains suffer from sensitivity to moisture content, leading to reduced cation conductivity and dimensional stability under low humidity conditions.
A polymer electrolyte membrane comprising a reaction product of a cation conductor with a phosphate ester, incorporating a phosphonic acid group, enhances cation conductivity and stability by forming crosslinks through hydrogen bonding, while minimizing swelling in humidified environments.
The membrane exhibits improved cation conductivity, stability, and durability, resulting in enhanced electrochemical and mechanical properties for water electrolysis and fuel cells.
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Figure KR2025006286_25062026_PF_FP_ABST
Abstract
Description
Polymer electrolyte membrane, method for manufacturing the same, membrane-electrode assembly and water electrolysis cell including the same, fuel cell
[0001] The invention relates to a polymer electrolyte membrane, a method for manufacturing the same, a membrane-electrode assembly including the same, a water electrolysis cell, and a fuel cell.
[0002] The present disclosure relates to the results of a project (Project No.: 00418612) carried out with the support of the Ministry of Trade, Industry and Energy (MOTIE) and the Korea Energy Technology Evaluation Institute (KETEP).
[0003]
[0004] Recent energy demands and environmental conditions require sustainable supply, eco-friendliness, and high efficiency, and among these, hydrogen is attracting attention as a raw material for renewable energy.
[0005] In a system of a Polymer Electrolyte Membrane Water Electrolysis Cell (PEMWE), the Membrane Electrode Assembly (MEA) that actually generates hydrogen has a structure in which an oxygen evolution electrode, where the oxygen evolution reaction takes place, and a hydrogen evolution electrode, where the hydrogen evolution reaction takes place, are positioned with respect to a polymer electrolyte membrane containing a hydrogen ion-conducting polymer.
[0006] Polymer electrolyte fuel cells (PEMFCs) are known to be the most promising for transportation systems as well as small-scale stationary power generation equipment, as they operate at low temperatures compared to other fuel cells and enable miniaturization due to their high power density.
[0007] A technology is known to apply cationic conductors having sulfonic acid side chains to such polymer electrolyte membranes for water electrolysis or fuel cells.
[0008] However, the cation conductivity of cation conductors with sulfonic acid side chains is sensitive to moisture content and is vulnerable under low humidity conditions; increasing the ion exchange capacity (IEC) to improve cation conductivity may instead lead to excessive membrane expansion and reduced dimensional stability.
[0009]
[0010] One embodiment provides a polymer electrolyte membrane that can improve cation conductivity, stability in humidified environments, and durability while using a cation conductor.
[0011]
[0012] One embodiment provides a polymer electrolyte membrane comprising a reaction product of a raw material mixture including a cation conductor and a phosphate ester, wherein the cation conductor includes at least one cation exchanger as a side chain and the phosphate ester includes a phosphonic acid group.
[0013]
[0014] A polymer electrolyte membrane according to one embodiment includes a cation conductor, and has improved cation conductivity and limited swelling in a humidified environment, thereby improving stability and durability.
[0015] Accordingly, a water electrolysis cell or fuel cell manufactured by assembling the above-mentioned polymer electrolyte membrane as a membrane-electrode assembly may have excellent electrochemical properties, mechanical properties, etc.
[0016]
[0017] FIG. 1 schematically illustrates the reaction product of a raw material mixture comprising a cation conductor, an amine compound, and a phosphate ester according to one embodiment.
[0018] FIG. 2 schematically illustrates an example in which a phosphate ester according to one embodiment forms a chelate with a metal ion.
[0019] FIG. 3 schematically illustrates a polymer electrolyte membrane with a reinforced membrane structure according to one embodiment.
[0020]
[0021] Hereinafter, embodiments of the present disclosure are described in detail so that those skilled in the art to which the present disclosure pertains can easily implement them. However, the present disclosure may be embodied in various different forms and is not limited to the embodiments described herein.
[0022] In this specification, “combination thereof” means a mixture of components, laminates, composites, copolymers, alloys, blends, reaction products, etc.
[0023] In this specification, terms such as “comprising,” “having,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.
[0024] In this specification, terms are used solely for the purpose of distinguishing one component from another. The singular expression includes the plural expression unless the context clearly indicates otherwise.
[0025]
[0026] polymer electrolyte membrane
[0027] One embodiment provides a polymer electrolyte membrane comprising a reaction product of a raw material mixture including a cation conductor and a phosphate ester, wherein the cation conductor includes at least one cation exchanger as a side chain and the phosphate ester includes a phosphonic acid group.
[0028]
[0029] One embodiment can enhance the effects of improved cation conductivity, stability in humidified environments, and durability by applying a reaction product having a structure in which the phosphate ester is incorporated into the cation conductor.
[0030] In one embodiment, as will be described later, an amine compound may be additionally applied to the raw material mixture. FIG. 1 schematically illustrates the reaction product of a raw material mixture comprising a cation conductor, an amine compound, and a phosphate ester according to one embodiment.
[0031] As illustrated in FIG. 1, the reaction product of the cation conductor (e.g., including a sulfonic acid group as an ion exchanger), an amine compound (e.g., 1,3,5-triazine-2,4,6-triamine), and a phosphate ester (e.g., phytic acid) has a structure in which the phosphate ester is grafted onto the cation conductor under the mediation of the amine compound.
[0032] The reaction product of the above cation conductor, amine compound, and phosphate ester can improve the cation conductivity of the polymer electrolyte membrane and limit swelling in a humidified environment by forming a crosslink between the ion exchanger of the cation conductor, the amine compound, and phytic acid, in contrast to the cation conductor itself.
[0033] Meanwhile, as shown in FIG. 2, the phosphate ester (e.g., phytic acid) can prevent the phenomenon of reduced ion conductivity caused by metal ion contamination through a strong chelation action with metal ions (e.g., platinum ions, zinc ions, etc.).
[0034]
[0035] A polymer electrolyte membrane of one embodiment is described in detail below.
[0036]
[0037] cation conductor
[0038] The above cation conductor comprises a hydrocarbon-based ion conductor, a fluorine-based ion conductor, or a combination thereof, and comprises at least one cation exchanger as a side chain, wherein the cation exchanger may comprise a sulfonic acid group, a phosphate group, or a combination thereof.
[0039]
[0040] The above fluorine-based ion conductor may be (i) a fluorine-based polymer having fluorine in a main chain and having at least one sulfonic acid group as a side chain; (ii) having a main chain of a partially fluorinated polymer such as a polystyrene-graft-ethylene-tetrafluoroethylene copolymer, a polystyrene-graft-polytetrafluoroethylene copolymer, etc., and having at least one sulfonic acid group as a side chain; or a combination thereof.
[0041] For example, the above-mentioned fluorine-based ion conductor comprises (i) poly(perfluorosulfonic acid), (ii) poly(perfluorocarboxylic acid), (iii) a copolymer of tetrafluoroethylene and fluorovinyl ether containing a sulfonic acid group, and (iv) defluorinated sulfated polyetherketone, but is not limited to these.
[0042] The above hydrocarbon-based ion conductor may include, for example, a structure selected from imidazole, benzimidazole, polybenzoxazole, polybenzthiazole, polyamide, polyamideimide, polyimide, polyimidesulfone, polyacetal, polyethylene, polypropylene, acrylic resin, polyester, polysulfone, polyether, polyetherimide, polyarylene ether-based polymer, polyarylene ketone, polyarylenephosphine oxide, polyester, polyethersulfone, polycarbonate, polystyrene, polyphenylene-based polymer, polyphenylene oxide, polyphenylene sulfide, polyphenylene sulfidesulfone, polyparaphenylene, polyetheretherketone, polyetherketone, polyetherphosphine oxide, polyarylethersulfone, polyphosphazene, and polyphenylquinoxaline in its main chain, wherein the above polysulfone, polyethersulfone, polyetherketone, etc., have sulfone bonds in the molecular chain. A general term for structures having ether bonds and / or ketone bonds, wherein the hydrocarbon ion conductor may have these structures and / or a combination of these structures as a main chain and include at least one sulfonic acid group as a side chain.
[0043] For example, the hydrocarbon-based ion conductor is sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (SPEEK), sulfonated polybenzimidazole (SPBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S-PS), sulfonated polyphosphazene, sulfonated polyquinoxaline, sulfonated polyketone, sulfonated polyphenylene oxide, sulfonated polyether sulfone, sulfonated polyether ketone, sulfonated sulfonated polyphenylene sulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene sulfide sulfone, sulfonated polyphenylene sulfide sulfone nitrile, sulfonated polyarylene ether, sulfonated polyarylene ether nitrile,and sulfonated polyarylene ether sulfone ketones, but are not limited to these.
[0044]
[0045] The above cation conductor may have a weight-average molecular weight of 10,000 to 10,000,000 mol / g, 30,000 to 6,000,000 mol / g, or 50,000 to 300,000 mol / g as measured by the GPC method. Within this range, a cation conductor that is desirable in terms of process aspects such as solution preparation and coating can be selected based on the mechanical properties of the polymer electrolyte membrane.
[0046]
[0047] Phosphate ester
[0048] The above phosphate ester is a compound containing at least one phosphonic acid group in one molecule, and may be phytic acid.
[0049] For every 1 mole of ion exchanger included in the above cation conductor, the phosphate ester may be included in an amount of 0.01 to 3 moles, 0.05 to 2 moles, or 0.1 to 1 mole.
[0050] In this range, the cation conductivity of the polymer electrolyte membrane can be increased due to the presence of a cation exchanger, while forming crosslinks through hydrogen bonding of the amine compound and the phosphate ester, and limiting excessive self-aggregation, thereby improving the stability and durability of the polymer electrolyte membrane.
[0051]
[0052] amine compounds
[0053] The above amine compound can be cross-linked to the cation exchanger of the cation conductor and the phosphonic acid group of the phosphate ester, respectively.
[0054] For example, the amine compound may include at least a first amino group and a second amino group. In this case, the bond between the ion exchanger of the cation conductor - the amine compound - the phytic acid may be due to hydrogen bonding between the first amino group of the amine compound and the sulfonic acid group of the cation conductor; and hydrogen bonding between the second amino group of the amine compound and the phosphonic acid group of the phosphate ester.
[0055] As the number of amino groups of the above amine compound increases, the number of such hydrogen bonds also increases, and the stability and durability of the reaction product may increase.
[0056]
[0057] For example, the above amine compounds are diethylene triamine, tris(2-aminoethyl)amine, 1,3,5-triaminobenzene, melamine, l-asparagine, l-glutamine, 1,1':4',1''-terphenyl]-3,3'',5,5''-tetraamine, 3,3',4,4'-tetraaminobiphenyl, and 4,4'-diaminostilbene-2,2'-disulfonic acid. 2,2'-Benzidinedisulfonic acid, 4,6-Diaminobenzene-1,3-Disulfonic acid, 9,9-Bis(4-aminophenyl)fluorene-2,7-Disulfonic acid, Sulfanilamide, Sulfamide, 2,5-Diaminobenzene-1,4-Disulfonic acid, 4-Aminophenyl sulfone, 4,8-Diaminonaphthalene-2,6-Disulfonic acid It may include 2,5-diaminobenzenesulfonic acid, 4,4'-diamino-[1,1'-biphenyl]-2,2'-disulfonic acid, or a combination thereof.
[0058]
[0059] For every 1 mole of ion exchanger included in the above cation conductor, the amine compound may be included in an amount of 0.01 to 3 moles, 0.05 to 2 moles, or 0.1 to 1 mole.
[0060] In this range, the cation conductivity of the polymer electrolyte membrane can be increased due to the presence of a cation exchanger, while forming crosslinks through hydrogen bonding of the amine compound and the phosphate ester, and limiting excessive self-aggregation, thereby improving the stability and durability of the polymer electrolyte membrane.
[0061]
[0062] Radical remover
[0063] When operating a water electrolysis cell or fuel cell containing the above polymer electrolyte membrane, hydrogen peroxide and hydroxyl radicals are generated in a chain, and the chain of the cation conductor may be broken by the hydroxyl radicals.
[0064] In this regard, the polymer electrolyte membrane may further include a radical scavenger.
[0065] The radical scavenger may include cerium, ruthenium, palladium, silver, rhodium, yttrium, manganese, molybdenum, lead, vanadium, titanium, their ionic forms, their oxides, their salts, or a mixture thereof, as transition metal ions capable of decomposing the hydrogen peroxide into water and oxygen to suppress the generation of hydroxyl radicals.
[0066] For example, the radical scavenger may include CeO2, MnO2, CsO2, ZrO2, Ru, Ag, RuO2, WO3, Fe3O4, CePO4, CrPO4, AlPO4, FePO4, CeF3, FeF3, Ce2(CO3)3·8H2O, Ce(CHCOO)3·H2O, CeCl3·6H2O, Ce(NO3)6·6H2O, Ce(NH4)2(NO3)6, Ce(NH4)4(SO4)4·4H2O, Ce(CH3COCHCOCH3)3·3H2O, Fe-porphyrin, Co-porphyrin, or a mixture thereof.
[0067] When the above radical scavenger is introduced, it may combine with the cation conductor included in the polymer electrolyte membrane and electrode, causing a decrease in ion conductivity, and may leak out during the system operation process, leading to a decrease in durability. Therefore, by minimizing the combination of the radical scavenger with the cation conductor and the leakage during the operation process, it is expected that the safety and durability of the polymer electrolyte membrane containing it can be improved.
[0068]
[0069] Structure of polymer electrolyte membranes
[0070] The polymer electrolyte membrane of one embodiment may have a structure of a single membrane or a reinforced membrane.
[0071]
[0072] The above single membrane may consist solely of the reaction product of a raw material mixture comprising the above cation conductor and phosphate ester. Of course, the above raw material mixture may further include the above amine compound.
[0073]
[0074] As shown in FIG. 3, the reinforcing film (50) may include a first coating layer (54) and a second coating layer (56). Specifically, the first coating layer (54) may be disposed on a first surface (52a) of the porous support (52), and the second coating layer (56) may be disposed on a second surface (52b) opposite to the first surface (52a). Accordingly, the coating layer (55) may be formed on the surface of the porous support (52) and may include a reaction product of a raw material mixture comprising the aforementioned cation conductor and phosphate ester. Here, the raw material mixture may further include the amine compound.
[0075] The porosity of the porous support (52) may be 30 to 90%, and preferably 60 to 85%. If the porosity of the porous support (52) is less than the above numerical range, a problem of reduced impregnation of the mixed polymer solution may occur, and if it exceeds the above numerical range, shape stability may be reduced, which may prevent the subsequent process from proceeding smoothly.
[0076] The above porosity can be calculated by the ratio of the volume of air within the porous support to the total volume of the porous support according to the following Equation 1. At this time, the total volume is calculated by manufacturing a rectangular sample and measuring its width, length, and thickness, and the volume of air is obtained by measuring the mass of the sample and subtracting the volume of the polymer, which is inversely calculated from the density, from the total volume.
[0077] [Equation 1]
[0078] Porosity (%) = (Volume of air in porous support / Total volume of porous support) X 100
[0079]
[0080] The porous support (52) may be a fluorine-based support or a nanoweb support.
[0081] The above-mentioned fluorine-based support may correspond, for example, to expanded polytetrafluoroethylene (e-PTFE) having a microstructure of polymer fibrils or a microstructure in which nodes are connected to each other by fibrils. Additionally, a film having a microstructure of polymer fibrils in which nodes are not present may also be used as the above-mentioned porous support (52).
[0082] The above fluorine-based support may include a perfluorinated polymer. The porous support (52) may correspond to a more porous and stronger porous support by extruding dispersed polymerized PTFE onto a tape in the presence of a lubricant and stretching the material obtained thereby.
[0083] In addition, the amorphous content of the PTFE may be increased by heat-treating the e-PTFE at a temperature exceeding the melting point (approx. 342°C) of the PTFE. The e-PTFE film produced by the above method may have micropores of various diameters and porosity. The e-PTFE film produced by the above method may have at least 35% porosity, and the diameter of the micropores may be approximately 0.01 to 1 μm (micrometer).
[0084] The nanoweb support may be a non-woven fibrous web composed of a plurality of randomly oriented fibers. The non-woven fibrous web refers to a sheet having the structure of individual fibers or filaments that are interlaid but not in the same manner as a woven fabric. The non-woven fibrous web may be manufactured by any one method selected from the group consisting of carding, garneting, air-laying, wet-laying, melt blowing, spun bonding, and stitch bonding.
[0085] The above fiber may comprise one or more polymer materials, and any material generally used as a fiber-forming polymer material may be used; specifically, hydrocarbon-based fiber-forming polymer materials may be used. For example, the fiber-forming polymer material may comprise any one selected from the group consisting of polyolefins, e.g., polybutylene, polypropylene, and polyethylene; polyesters, e.g., polyethylene terephthalate and polybutylene terephthalate; polyamides (Nylon-6 and Nylon-6,6); polyurethanes, polybutene; polylactic acid; polyvinyl alcohol; polyphenylene sulfide; polysulfone; fluid crystalline polymers; polyethylene-co-vinyl acetate; polyacrylonitrile; cyclic polyolefins; polyoxymethylene; polyolefin-based thermoplastic elastomers; and combinations thereof. However, the technical concept of the present invention is not limited thereto.
[0086] The above nanoweb support may be a support in which nanofibers are integrated in the form of a nonwoven fabric containing a number of pores.
[0087] The above nanofibers may preferably be hydrocarbon-based polymers that exhibit excellent chemical resistance and hydrophobicity, so there is no concern about shape deformation due to moisture in high-humidity environments. Specifically, the above hydrocarbon-based polymer may be selected from the group consisting of nylon, polyimide, polyaramid, polyetherimide, polyacrylonitrile, polyaniline, polyethylene oxide, polyethylene naphthalate, polybutylene terephthalate, styrene butadiene rubber, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyvinylidene fluoride, polyvinyl butylene, polyurethane, polybenzoxazole, polybenzimidazole, polyamideimide, polyethylene terephthalate, polyphenylene sulfide, polyethylene, polypropylene, copolymers thereof, and mixtures thereof.
[0088] The above nanoweb support is an aggregate of nanofibers in which nanofibers manufactured by electrospinning are randomly arranged. In this case, considering the porosity and thickness of the nanoweb, it is preferable that the nanofibers have an average diameter of 40 to 5000 nm (nanometers) when 50 fiber diameters are measured using a scanning electron microscope (JSM6700F, JEOL) and calculated from the average.
[0089] If the average diameter of the nanofiber is less than the above numerical range, the mechanical strength of the porous support may be reduced, and if the average diameter of the nanofiber exceeds the above numerical range, the porosity may be significantly reduced and the thickness may be increased.
[0090] The thickness of the nonwoven fiber web may be 3 to 60 μm (micrometers), specifically 8 to 50 μm (micrometers). If the thickness of the nonwoven fiber web is less than the above numerical range, the mechanical strength may decrease, and if it exceeds the above numerical range, the resistance loss increases, and the lightweighting and integration may decrease.
[0091] The above nonwoven fibrous web has a basic weight of 5 to 30 mg / cm² 2 It may be. If the basis weight of the above nonwoven fibrous web is less than the above numerical range, visible pores may be formed, making it difficult to function as a porous support, and if it exceeds the above numerical range, it may be manufactured in the form of paper or fabric in which pores are hardly formed.
[0092]
[0093] Thickness of the polymer electrolyte membrane
[0094] The thickness of the polymer electrolyte membrane may be, for example, 5 to 200 μm. However, it is not limited thereto, and various thickness ranges may be applied.
[0095]
[0096] Method for manufacturing a polymer electrolyte membrane
[0097] One embodiment provides a method for manufacturing a polymer electrolyte membrane, comprising the steps of: mixing a phosphate ester solution and a cation conductor solution to prepare a raw material mixture; reacting the raw material mixture to prepare a polymer electrolyte membrane forming solution containing a reaction product of the raw material mixture; and forming the polymer electrolyte membrane forming solution, wherein the cation conductor includes at least one cation exchange group as a side chain and the phosphate ester includes a phosphonic acid group.
[0098]
[0099] Through this, the polymer electrolyte membrane of the aforementioned embodiment can be manufactured.
[0100]
[0101] Hereinafter, descriptions that overlap with the above content will be omitted, and a manufacturing method of one embodiment will be described in detail.
[0102]
[0103] Preparation and mixing steps of the raw material solution
[0104] The above cation conductor and the above phosphate ester can each be dissolved in a polar amphoteric solvent such as DMSO, DMAc, DMF, or NMP to prepare a cation conductor solution and a phosphate ester solution.
[0105]
[0106] The above phosphate ester solution and the above cation conductor solution may be mixed to include a raw material mixture.
[0107]
[0108] *107
[0109] Before mixing the phosphate ester solution and the cation conductor solution, an amine compound and / or a radical scavenger may be added to the phosphate ester solution. The phosphate ester solution to which the amine compound has been added may be referred to as a mixed solution of the amine compound and the phosphate ester.
[0110]
[0111] The description of the above-mentioned cation conductor, the above-mentioned phosphate ester, and the above-mentioned amine compound is as described above.
[0112]
[0113] Reaction stage of the raw material mixture
[0114] A cation conductor solution can be introduced into the above phosphate ester solution and reacted. In this process, a reaction product having a structure in which the phosphate ester is grafted onto the cation conductor can be formed.
[0115] When the above-mentioned amine compound and phosphate ester mixed solution is used, a reaction product having a structure in which the phosphate ester is grafted onto the cation conductor under the mediation of the amine compound can be formed.
[0116]
[0117] Step of obtaining a polymer electrolyte membrane
[0118] The step of forming the polymer electrolyte film forming solution described above may involve forming an electrolyte film by applying the polymer electrolyte film forming solution prepared as described above onto a substrate (e.g., a glass substrate) and then drying and / or heat treating. The drying temperature may be 20 to 120 ℃, and the heat treatment temperature may be 120 to 300 ℃.
[0119] Through this, the aforementioned single-membrane structure polymer electrolyte membrane can be obtained.
[0120]
[0121] Alternatively, the step of forming the polymer electrolyte membrane forming solution may include the step of applying the polymer electrolyte membrane forming solution to one or both sides of a porous support.
[0122] After the step of applying the polymer electrolyte membrane forming solution to one or both sides of the porous support, the method may further include a step of drying the applied product. The drying temperature may be 20 to 120 ℃.
[0123]
[0124] Through this, the polymer electrolyte membrane of the aforementioned embodiment can be manufactured.
[0125]
[0126] Hereinafter, descriptions that overlap with the above content will be omitted, and a manufacturing method of one embodiment will be described in detail.
[0127]
[0128] Membrane-electrode assemblies, water electrolysis cells, and fuel cells
[0129] The above polymer electrolyte membrane can be used as an electrolyte membrane for water electrolysis cells requiring cation conductivity, an electrolyte membrane for fuel cells, etc.
[0130]
[0131] One embodiment provides a membrane-electrode assembly for a water electrolysis cell comprising: a hydrogen generating electrode; an oxygen generating electrode; and a polymer electrolyte membrane according to the above-described embodiment located between the hydrogen generating electrode and the hydrogen generating electrode.
[0132] One embodiment provides a water electrolysis cell comprising a membrane-electrode assembly for the water electrolysis cell.
[0133]
[0134] One embodiment provides a membrane-electrode assembly for a fuel cell comprising: an anode electrode; a cathode electrode; and a polymer electrolyte membrane of the above-described embodiment located between the anode electrode and the cathode electrode.
[0135] One embodiment provides a fuel cell comprising a membrane-electrode assembly for the fuel cell.
[0136]
[0137] The above membrane-electrode assembly for a water electrolysis cell and the water electrolysis cell including the same are described below.
[0138] The catalyst layer included in the oxygen generation electrode comprises a catalyst for an oxygen generation reaction and an ion conductor, and the catalyst for the oxygen generation reaction comprises active particles comprising a precious metal oxide.
[0139] The above precious metal oxide is not limited in type as long as it can be applied as a catalyst for the oxygen evolution reaction of a water electrolysis cell.
[0140] For example, the above precious metal oxide is IrO x (The above x is an integer from 1 to 3), RuO x (The above x is an integer from 1 to 3), IrMO x (M comprises Ru, Pt, Sn, Se, Sb, Ta, Te, Nb, W, Zn, Au or a combination thereof, and x is an integer from 1 to 3), or may comprise a combination thereof.
[0141] The above catalyst for the oxygen generation reaction may use only the active particle alone, or may further include a carrier that supports the active particle.
[0142] The above-mentioned carrier is not limited in type as long as it can be applied to a catalyst for the oxygen generation reaction of a water electrolysis cell.
[0143] For example, the carrier may be a metal oxide, and the carrier may be titanium dioxide (TiO2).
[0144] The above ion conductor is included to improve the adhesion of the catalyst layer and to transport hydrogen ions.
[0145] The ion conductor included in the oxygen generating electrode and the ion conductor included in the reinforced polymer electrolyte membrane for the water electrolysis cell may be the same.
[0146] The above hydrogen generation electrode may include a catalyst for a hydrogen generation reaction. The above catalyst for a hydrogen generation reaction may include active particles and a support material that supports the active particles.
[0147] The above active particles may include precious metals.
[0148] For example, the above precious metal may be a platinum-based precious metal.
[0149] Platinum (Pt) and / or a Pt-M alloy may be used as the platinum-based precious metal. M may be palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), gallium (Ga), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), zinc (Zn), tin (Sn), molybdenum (Mo), tungsten (W), lanthanum (La), or rhodium (Rh).
[0150] Specifically, as the above Pt-M alloy, Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ni, Pt-Co, Pt-Y, Pt-Ru-W, Pt-Ru-Ni, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Ru-Ir-Ni, Pt-Co-Mn, Pt-Co-Ni, Pt-Co-Fe, Pt-Co-Ir, Pt-Co-S, Pt-Co-P, Pt-Fe, Pt-Fe-Ir, Pt-Fe-S, Pt-Fe-P, Pt-Au-Co, Pt-Au-Fe, Pt-Au-Ni, Pt-Ni, Pt-Ni-Ir, Pt-Cr, Pt-Cr-Ir, or a mixture thereof may be used. there is.
[0151] The above carrier may be a carbon-based carrier.
[0152] The carbon-based carrier may be graphite, super P, carbon fiber, carbon sheet, carbon black, Ketjen black, Denka black, acetylene black, carbon nanotube (CNT), carbon sphere, carbon ribbon, fullerene, activated carbon, carbon nanofiber, carbon nanowire, carbon nanoball, carbon nanohorn, carbon nanocage, carbon nanoring, ordered nano- / meso-porous carbon, carbon aerogel, mesoporous carbon, graphene, stabilized carbon, activated carbon, or a combination thereof.
[0153] The oxygen generation electrode and the hydrogen generation electrode may each include only a catalyst layer comprising a catalyst for an oxygen generation reaction and a catalyst for a hydrogen generation reaction, respectively, but may also include an electrode substrate together with the catalyst layer.
[0154] At this time, the electrode substrate can perform the role of supporting the electrode while diffusing fuel and oxidant into the catalyst layer.
[0155] The above electrode substrate may be any known electrode substrate without specific limitations, but specifically, carbon paper, carbon cloth, carbon felt, or metal cloth that can be used as a conductive substrate (referring to a porous film composed of a metal cloth in a fibrous state or a metal film formed on the surface of a cloth formed of polymer fibers).
[0156] The above electrode substrate may be treated with a fluorine-based resin for water repellency, in which case the reduction in reactant diffusion efficiency caused by water generated after operating the water electrolysis cell can be prevented.
[0157] As the above fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polyperfluoroalkyl vinyl ether, polyperfluorosulfonyl fluoride, alkoxyvinyl ether, fluorinated ethylene propylene, polychlorotrifluoroethylene, or copolymers thereof may be used.
[0158]
[0159] A water electrolysis cell according to one embodiment may include the membrane-electrode assembly.
[0160] Since the above-mentioned water electrolysis cell is identical to the known one except for including the above-mentioned membrane-electrode assembly, a detailed description is omitted.
[0161]
[0162] The above-described membrane-electrode assembly for a fuel cell and the fuel cell including the same are described below.
[0163] A membrane-electrode assembly according to one embodiment is a membrane-electrode assembly comprising the polymer electrolyte membrane, wherein the anode electrode and a cathode electrode are positioned opposite each other, and the polymer electrolyte membrane is positioned between the anode electrode and the cathode electrode.
[0164] The above anode and cathode electrodes include an electrode substrate and a catalyst layer formed on the surface of the electrode substrate, and may further include a microporous layer containing conductive fine particles such as carbon powder or carbon black between the electrode substrate and the catalyst layer to facilitate material diffusion from the electrode substrate.
[0165] The catalyst layers of the anode and cathode electrodes described above contain a catalyst. Any catalyst that participates in the reaction of the cell and is typically usable as a catalyst for a fuel cell may be used. Preferably, a platinum-based metal may be used.
[0166] The above platinum-based metal may include one selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), platinum-M alloys, non-platinum alloys, and combinations thereof, and more preferably, a combination of two or more metals selected from the group of platinum-based catalyst metals may be used, but is not limited thereto, and any platinum-based catalyst metal available in the field of the present technology may be used without limitation.
[0167] The above M may correspond to one or more selected from the group consisting of palladium (Pd), ruthenium (Ru), iridium (Ir), osmium (Os), gallium (Ga), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), zinc (Zn), tin (Sn), molybdenum (Mo), tungsten (W), lanthanum (La), and rhodium (Rh). Specifically, the platinum alloy mentioned above may be used alone or in a mixture of two or more selected from the group consisting of Pt-Pd, Pt-Sn, Pt-Mo, Pt-Cr, Pt-W, Pt-Ru, Pt-Ru-W, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Co, Pt-Co-Ni, Pt-Co-Fe, Pt-Co-Ir, Pt-Co-S, Pt-Co-P, Pt-Fe, Pt-Fe-Ir, Pt-Fe-S, Pt-Fe-P, Pt-Au-Co, Pt-Au-Fe, Pt-Au-Ni, Pt-Ni, Pt-Ni-Ir, Pt-Cr, Pt-Cr-Ir, and combinations thereof.
[0168] In addition, the above-mentioned non-platinum alloy may be used alone or in a mixture of two or more selected from the group consisting of Ir-Fe, Ir-Ru, Ir-Os, Co-Fe, Co-Ru, Co-Os, Rh-Fe, Rh-Ru, Rh-Os, Ir-Ru-Fe, Ir-Ru-Os, Rh-Ru-Fe, Rh-Ru-Os, and combinations thereof.
[0169] The above catalyst may be used as the catalyst itself (black) or supported on a carrier.
[0170]
[0171] A fuel cell according to one embodiment may include the membrane-electrode assembly.
[0172] Since the above fuel cell is identical to the known one except for including the above membrane-electrode assembly, a detailed description is omitted.
[0173]
[0174] Hereinafter, embodiments are described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.
[0175]
[0176] (Single membrane)
[0177]
[0178] Example 1
[0179] (1) Preparation of polymer electrolyte membrane
[0180] As a cation conductor comprising at least one cation exchange group (specifically, a sulfonic acid group) as a side chain, SPAES (Sulfonated Poly(arylene ether sulfone) with a weight-average molecular weight of 12,500 mol / g was prepared.
[0181] The above cation conductor was added to DMSO at a concentration of 15 wt% and stirred at 80°C for 6 hours to prepare a cation conductor solution.
[0182] Melamine was prepared as an amine compound comprising at least one sulfonic acid group as a side chain; and at least two (specifically, two) amino groups as a side chain, a terminal, or a combination thereof. Additionally, phytic acid was prepared as a phosphate ester comprising a phosphonic acid group.
[0183] The above phosphate ester was added to DMSO at a concentration of 15 wt%, and 1 mole of the above amine compound was added based on 1 mole of the above phosphate ester, and then stirred at 80°C for 3 hours to prepare a mixed solution of the phosphate ester and the amine compound.
[0184] The above-mentioned phosphate ester and amine compound mixed solution and the above-mentioned cation conductor solution were mixed in a weight ratio of 1:1 and stirred at 80°C for 6 hours to prepare a polymer electrolyte membrane forming solution containing a reaction product of a raw material mixture comprising a cation conductor, an amine compound, and a phosphate ester.
[0185] After applying the above polymer electrolyte membrane forming solution onto a glass substrate, it was dried in an 80°C convection oven for 24 hours. Here, a single membrane for a fuel cell with a thickness of 15 μm and a single membrane for water electrolysis with a thickness of 70 μm were each prepared.
[0186] (2) Manufacture of membrane-electrode assembly for water electrolysis
[0187] IrO as a catalyst for oxygen evolution reaction x 5 g of / TiO2 (Alfa Aesar, 43396), 12.5 g of Nafion D2021 (Dupont) as an ion conductor, and water and n-propanol as solvents in a weight ratio of 4:6
[0188] A composition mixed with (=water:n-propanol) was dispersed using a homogeneous mixer to prepare a composition for forming a first electrode.
[0189] A second electrode composition was prepared by dispersing a composition in a homogeneous mixer that included 5g of Pt / C (Tanaka, TEC10E50E) as a catalyst for hydrogen generation reaction, 10g of Nafion D2021 (Dupont) as an ion conductor, and water and n-propanol as solvents in a weight ratio of 4:6 (=water:n-propanol).
[0190] 1.0 mg / cm² of the above-mentioned first electrode-forming composition on the first surface of a polyimide film of PI Advanced Materials Co., Ltd. having a thickness of 150 μm as a release film 2 , the above second electrode forming composition is applied to the second surface facing the first surface at a concentration of 0.2 mg / cm 2After applying with a doctor blade to achieve the desired result, the first electrode (oxygen generating electrode) was prepared on the first surface and the second electrode (hydrogen generating electrode) was prepared on the second surface by drying at 60°C for 8 hours.
[0191] A fluorine-based polymer electrolyte membrane is interposed between the first electrode and the second electrode manufactured above, and at 160°C and 20 kgf / cm² 2 A membrane-electrode assembly in which the first electrode and the second electrode are bonded to a polymer electrolyte membrane was manufactured by applying heat and pressure for 3 minutes under certain conditions and then peeling off the polyimide film.
[0192] (3) Manufacture of membrane-electrode assembly for fuel cell
[0193] A composition for forming an electrode was prepared by mixing 5g of Pt / C (Tanaka, TEC10E50E) as a catalyst, 10g of Nafion D2021 (Dupont) as an ion conductor, and 25g of a mixture of dipropylene glycol and distilled water in a weight ratio of 1:1 (=dipropylene glycol:distilled water) as a solvent, and uniformly dispersing the composition using a 3-roll mill (EXAKT 50).
[0194] 0.1 mg / cm² of the above electrode-forming composition on the first surface of a Teflon release film 2 , 0.4 mg / cm on the second surface facing the first surface above 2 After applying with a doctor blade to achieve the desired result, the first electrode was prepared on the first surface and the second electrode on the second surface by drying at 60°C for 8 hours.
[0195] A hydrocarbon-based polymer electrolyte membrane is interposed between the first electrode and the second electrode, and at 160°C and 20 kgf / cm² 2 A membrane-electrode assembly for a fuel cell, in which the first electrode and the second electrode are bonded to a hydrocarbon-based polymer electrolyte membrane, was manufactured by applying heat and pressure for 3 minutes under certain conditions and then peeling off the Teflon release film.
[0196]
[0197] Example 2
[0198] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were manufactured substantially identically, except that in Example 1 above, a phosphate ester solution was prepared that did not contain an amine compound and contained only a phosphate ester, and a polymer electrolyte membrane forming solution containing a reaction product of a raw material mixture containing a cation conductor and a phosphate ester was prepared and used accordingly.
[0199]
[0200] Example 3
[0201] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared in substantially the same manner as in Example 1 above, except that the weight ratio of the phosphate ester and amine compound mixed solution and the cation conductor solution was changed to 1:2.
[0202]
[0203] Example 4
[0204] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared in substantially the same manner as in Example 1 above, except that the weight ratio of the phosphate ester and amine compound mixed solution and the cation conductor solution was changed to 2:1.
[0205]
[0206] Example 5
[0207] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were manufactured substantially identically to the above Example 1, except that melamine was changed to tris(2-aminoethyl)amine.
[0208]
[0209] Example 6
[0210] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared substantially identically, except that 0.01 parts by weight of cerium sulfate was added to the mixed solution of the phosphate ester and amine compound relative to 1 part by weight of the cation conductor in Example 1 above.
[0211]
[0212] Example 7
[0213] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were manufactured substantially identically, except that the SPAES ion conductor was replaced with Nafion powder, a fluorine-based ion conductor, in Example 1 above.
[0214]
[0215] Comparative Example 1
[0216] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared in substantially the same manner as in Example 1, except that no amine compounds or phosphate esters were used.
[0217]
[0218] Comparative Example 2
[0219] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were manufactured substantially identically, except that the SPAES ion conductor was replaced with Nafion powder, a fluorine-based ion conductor, in Comparative Example 1 above.
[0220]
[0221] (Reinforcement)
[0222]
[0223] Example 8
[0224] A polymer electrolyte membrane forming solution according to Example 1 was impregnated into a PPS (polyphenylene sulfide) support having an average pore size of 0.2 μm and a porosity of 70%, and then the impregnated product was dried at 80°C for 24 hours to produce a polymer electrolyte membrane with a reinforced membrane structure.
[0225] A membrane-electrode assembly for water electrolysis and a membrane-electrode assembly for fuel cells were manufactured in substantially the same manner as in Example 3, except that a polymer electrolyte membrane with the above-mentioned reinforced membrane structure was used.
[0226]
[0227] Example 9
[0228] A polymer electrolyte membrane was prepared by impregnating an e-PTFE (expanded-polytetrafluoroethylene) support having an average pore size of 0.2 μm and a porosity of 75% with a polymer electrolyte membrane forming solution according to Example 7, and then drying the impregnated PTFE (polytetrafluoroethylene) support at 80°C for 12 hours.
[0229]
[0230] Comparative Example 3
[0231] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared in substantially the same manner as in Example 8, except that a cation conductor solution according to Comparative Example 1 was used.
[0232]
[0233] Comparative Example 4
[0234] A polymer electrolyte membrane, a membrane-electrode assembly for water electrolysis, and a membrane-electrode assembly for a fuel cell were prepared in substantially the same manner as in Example 9, except that a cation conductor solution according to Comparative Example 2 was used.
[0235]
[0236] Evaluation Example 1: Evaluation of Polymer Electrolyte Membrane
[0237] (1) Water uptake rate (%)
[0238] The polymer electrolyte membranes according to Examples 1 to 9 and Comparative Examples 1 to 4 were dried in a vacuum oven at 80°C for 12 hours, and then their weight was measured (W dry ). Subsequently, the same membrane was immersed in distilled water at room temperature for 24 hours, then removed, the water present on the surface was removed, and the weight was measured again (W wet The water absorption rate was calculated using the following Equation 2.
[0239] [Equation 2]
[0240] Water uptake rate (%) = 100*(W wet - W dry ) / W dry
[0241] (2) Rate of change in area and rate of change in volume (%)
[0242] The method for measuring the dimensional change rate of the polymer electrolyte membrane according to Examples 1 to 9 and Comparative Examples 1 to 4 was performed in the same manner as the method for measuring water absorption rate, but instead of measuring weight, the area and volume changes of the polymer electrolyte membrane were measured, and then each area change rate and volume change rate was calculated using Equations 3 and 4 below.
[0243] [Equation 3]
[0244] Area change rate (%) = 100 * [(Film area (wet)) - (Film area (dry))] / (Film area (dry))
[0245] [Equation 4]
[0246] Volume change rate (%) = 100 * [(Film area * Film thickness (wet)) - (Film area * Film thickness (dry))] / (Film area * Film thickness (dry))
[0247] (3) Cation conductivity measurement
[0248] Cation conductivity (Proton conductivity: σ) of polymer electrolyte membranes according to Examples 1 to 9 and Comparative Examples 1 to 4 above membrane ) was measured by the constant current four-terminal method. Specifically, the resistance (R) was determined by applying a constant alternating current to both sides of a polymer electrolyte membrane while controlling the relative humidity from 50% to 100% at a temperature of 80°C. The alternating potential difference generated within the membrane was measured. membrane ) was obtained, and the conductivity of the polymer electrolyte membrane (σ) was calculated using Equation 5 below. membrane ) was obtained. A Scribner Associates MTS 740 was used as the conductivity measuring device, and in-plane conductivity was measured.
[0249] [Equation 5]
[0250] Ionic conductivity (σ membrane )(mS / cm) = (distance between electrodes (L)) / [(film resistance (R) membrane ))*(film area(A))]
[0251]
[0252] Information on the polymer electrolyte membranes prepared in Examples 1 to 9 and Comparative Examples 1 to 4 is listed in Table 1 below, and the experimental results are shown in Table 2.
[0253]
[0254] Types of ion conductors, types of phosphate esters, types of amine compounds, input ratios *Radical Removal Membrane Structure Example 1 SPAES Melamine Phytate 1:1X Single Membrane Example 2 SPAES Phytate X 1:1X Single Membrane Example 3 SPAES Melamine Phytate 1:2X Single Membrane Example 4 SPAES Melamine Phytate 2:1X Single Membrane Example 5 SPAES Tris(2-Aminoethyl) Phytate 1:1X Single Membrane Example 6 SPAES Melamine Phytate 1:1 Cerium Sulfate Single Membrane Example 7 Nafion Melamine Phytate 1:1X Single Membrane Example 8 SPAES Melamine Phytate 1:1X Reinforced Membrane Example 9 Nafion Melamine Phytate 1:1X Reinforced Membrane Comparative Example 1 SPAES XXXX Single Membrane Comparative Example 2 Nafion XXXX Single Membrane Comparative Example 3 SPAES XXXX Reinforced Membrane Comparative Example 4NafionXXXX Reinforcement Shield
[0255] Input ratio * : Weight ratio of the above phosphate ester and amine compound mixed solution and the above cation-conducting polymer
[0256] Water absorption rate (%) Area change rate (%) Volume change rate (%) Cation conductivity (mS / cm, @80℃) RH 50% RH 100% Example 1 53.15.365.014.7117.2 Example 2 70.16.288.022.6114.8 Example 3 52.65.362.88.999.6 Example 4 60.35.871.527.5103.9 Example 5 58.25.968.110.3123.8 Example 6 52.85.264.511.8117.4 Example 7 12.87.228.719.9118.3 Example 8 35.40.317.110.371.5 Example 99.30.210.813.271.9 Comparative Example 151.85.265.17.483.4 Comparative Example 212.57.128.712.684.1 Comparative Example 331.11.220.33.545.7 Comparative Example 47.30.412.06.646.2
[0257] Referring to Tables 1 and 2 above, when phosphate esters were introduced, the cation conductivity of both hydrocarbon-based and fluorine-based ion conductors, as well as single and reinforced membranes, was improved compared to the comparative example without the introduction of phosphate esters, while the change in dimensional change rates, including the change rates in area and volume, was not significant. In particular, an improvement in cation conductivity under low humidity conditions can be expected, which can be further enhanced by adjusting the amount of the mixed solution of phosphate esters and amine compounds. When amine compounds are introduced, hydrogen bonds are formed with phytic acid, thereby stabilizing phytic acid which is soluble in water, while simultaneously stabilizing mechanical durability, including the rate of dimensional change. Furthermore, it was confirmed that this effect is maintained even when a radical scavenger is additionally introduced.
[0258] As described above, an improvement in cation conductivity can be expected when amine compounds and phosphate esters are introduced, and it can be seen that introducing amine compounds having two or more amino groups and sulfonic acid groups is particularly effective in improving mechanical stability.
[0259]
[0260] Evaluation Example 2: Evaluation of Performance and Durability of Membrane-Electrode Assembly
[0261] (Electrolytic cell)
[0262] The membrane-electrode assembly for the water electrolysis cell was evaluated for cell performance and chemical durability as follows.
[0263] The membrane-electrode assemblies for water electrolysis cells prepared in Examples 1 and 7 and Comparative Examples 1 and 2 were applied inside unit cells designed and fabricated for water electrolysis cells, and measurements were taken by applying a protocol to measure voltage and resistance at specific currents from 1 mA to 20 A under conditions of cell temperature 80°C, water temperature 80°C, and flow rate 5 ml / min. The current density was measured at a voltage of 1.8 V, and the higher the result value, the better the output performance.
[0264] Chemical durability was evaluated after the initial performance evaluation of the above membrane-electrode assembly at a cell temperature of 80°C and a current density of 1 A / cm². 2 The voltage growth rate was measured after driving a constant current for 500 hours. The voltage growth rate was measured using a BioLogic instrument and calculated according to Equation 6 below, and the results are shown in Table 3 below. During the evaluation process, the evaluation was terminated if the voltage growth rate was 20% or higher after reaching 100 hours.
[0265] [Equation 6]
[0266] Voltage Increase Rate (%) = 100 * (Voltage after driving - Initial voltage) / (Initial voltage)
[0267] Battery performance evaluation (A / cm) 2 Voltage Increase Rate (%) Example 1 2.36 19.3 Example 7 2.24 8.1 Comparative Example 11.76 74.6 (100 hours) Comparative Example 2 1.75 16.2
[0268] Referring to Table 3 above, the membrane-electrode assemblies of Examples 1 and 7 exhibited improved performance and durability compared to the membrane-electrode assemblies of Comparative Examples 1 and 2, thereby confirming that the hydrogen bonds formed when the phosphate ester and amine compounds are introduced have a substantial effect even at the cell stage (fuel cell).
[0269] The membrane-electrode assembly for fuel cells was evaluated for cell performance and chemical durability as follows.
[0270] Active area of 25 cm² prepared in Examples 1, 2, and 6 to 9; and Comparative Examples 1 and 2 2 of The output performance of the membrane-electrode assembly for the fuel cell was evaluated through IV measurement. Specifically, to verify the output performance under actual fuel cell operating conditions, the membrane-electrode assembly was tested using a fuel cell unit cell evaluation device (Scribner 850 fuel cell test system).
[0271] Under conditions of 65℃, hydrogen (100%RH) and air (100%RH) were supplied to the first electrode and the second electrode, respectively, in amounts corresponding to Stoichiometry 1.5 / 2.0. The current density was measured at a voltage of 0.6V, and the higher the result value, the better the output performance.
[0272] Chemical durability was evaluated by performing the OCV hold method for 500 hours under conditions of 90°C, RH 30%, and 50kPa after the initial performance evaluation of the membrane-electrode assembly for the fuel cell, and then measuring the voltage loss for each. The measured values are shown in Table 4 below. During the evaluation process, if the OCV loss was 20% or more, the evaluation was terminated.
[0273] Battery performance evaluation (A / cm) 2 )OCV Voltage Loss (%) Example 1 1.3820 (450 hours) Example 2 1.4220 (85 hours) Example 6 1.375.5 Example 7 1.3614.2 Example 8 1.3616.8 Example 9 1.358.3 Comparative Example 11.1220 (110 hours) Comparative Example 21.1820 (240 hours)
[0274] Referring to Table 4 above, it was confirmed that the membrane-electrode assemblies of Examples 1, 2, and 6 to 9 showed improved performance compared to the membrane-electrode assemblies of Comparative Examples 1 and 2. In the case of Example 2, which used only phytic acid, a phosphate ester, without an amine compound, the battery performance was the best, but a rapid OCV voltage loss occurred due to the water solubility of phytic acid. In the case of Examples 1 and 7 to 9, which used melamine as the amine compound, both performance and durability were improved, and in the case of Example 6, which introduced a radical scavenger, it was confirmed that it showed the best durability despite being a single membrane.
[0275] Thus, it can be seen that the effects of introducing phosphate esters and amine compounds, which were confirmed in the previous polymer electrolyte membrane and water electrolysis cell evaluation steps, are effective in improving performance and durability when applied to fuel cells, and further enhanced durability can be expected when a reinforced membrane containing a radical scavenger and / or a porous support is introduced.
Claims
1. A reaction product of a raw material mixture comprising a cation conductor and a phosphate ester, and The above cation conductor It includes at least one cation exchange group as a side chain, and The above phosphate ester Containing a phosphonic acid group, Polymer electrolyte membrane.
2. In Paragraph 1, The above cation conductor A hydrocarbon-based ion conductor, a fluorine-based ion conductor, or a combination thereof, comprising at least one cation exchanger as a side chain, The above cation exchanger comprises a sulfonic acid group, a phosphate group, or a combination thereof. Polymer electrolyte membrane.
3. In Paragraph 1, The above phosphate ester is phytic acid, Polymer electrolyte membrane.
4. In Paragraph 1, The above raw material mixture further comprises an amine compound, and The above amine compound comprises at least one sulfonic acid group as a side chain; and at least two amino groups as a side chain, a terminal, or a combination thereof. Polymer electrolyte membrane.
5. In Paragraph 4, The above amine compounds are diethylene triamine, tris(2-aminoethyl)amine, 1,3,5-triaminobenzene, melamine, l-asparagine, l-glutamine, 1,1':4',1''-terphenyl]-3,3'',5,5''-tetraamine, 3,3',4,4'-tetraaminobiphenyl, and 4,4'-diaminostilbene-2,2'-disulfonic acid. 2,2'-Benzidinedisulfonic acid, 4,6-Diaminobenzene-1,3-Disulfonic acid, 9,9-Bis(4-aminophenyl)fluorene-2,7-Disulfonic acid, Sulfanilamide, Sulfamide, 2,5-Diaminobenzene-1,4-Disulfonic acid, 4-Aminophenyl sulfone, 4,8-Diaminonaphthalene-2,6-Disulfonic acid 2,5-diaminobenzenesulfonic acid, 4,4'-diamino-[1,1'-biphenyl]-2,2'-disulfonic acid, or a combination thereof, comprising Polymer electrolyte membrane.
6. In Paragraph 1, The above polymer electrolyte membrane further comprises a radical scavenger, and Comprising cerium, ruthenium, palladium, silver, rhodium, yttrium, manganese, molybdenum, lead, vanadium, titanium, their ionic forms, their oxides, their salts, or mixtures thereof, Polymer electrolyte membrane.
7. In Paragraph 1, The above polymer electrolyte membrane is a single membrane, and The above single membrane is A mixture comprising the reaction product of a raw material mixture containing the above-mentioned cation conductor and phosphate ester, Polymer electrolyte membrane.
8. In Paragraph 1, The above polymer electrolyte membrane is a reinforced membrane, and The above reinforcing film is porous support and It includes a coating layer located on one or both sides of the above-mentioned porous support, and The above coating layer A mixture comprising the reaction product of a raw material mixture containing the above-mentioned cation conductor and phosphate ester, Polymer electrolyte membrane.
9. A step of preparing a raw material mixture by mixing a phosphate ester solution and a cation conductor solution; A step of reacting the above raw material mixture to prepare a polymer electrolyte membrane forming solution comprising the reaction product of the above raw material mixture; and The method includes the step of forming a polymer electrolyte membrane-forming solution, wherein The above cation conductor It includes at least one cation exchange group as a side chain, and The above phosphate ester Containing a phosphonic acid group, Method for manufacturing a polymer electrolyte membrane.
10. In Paragraph 9, Before mixing the above phosphate ester solution and the above cation conductor solution, Adding an amine compound to the above phosphate ester solution, Method for manufacturing a polymer electrolyte membrane.
11. In Paragraph 9, Before mixing the above phosphate ester solution and the above cation conductor solution, Adding a radical scavenger to the above phosphate ester solution, Method for manufacturing a polymer electrolyte membrane.
12. Hydrogen generating electrode; Oxygen generating electrode; and A polymer electrolyte membrane according to claim 1, positioned between the hydrogen generation electrode and the hydrogen generation electrode. Membrane-electrode assembly for water electrolysis cell.
13. A water electrolysis cell comprising a membrane-electrode assembly for a water electrolysis cell according to paragraph 12.
14. Anode electrode; cathode electrode; and A polymer electrolyte membrane according to claim 1, positioned between the anode electrode and the cathode electrode. Membrane-electrode assembly for a fuel cell.
15. A fuel cell comprising a membrane-electrode assembly for a fuel cell according to paragraph 14.