Membrane electrode assembly, method for manufacturing the same, fuel cell, and electrolytic cell

Abstract

The present invention relates to a membrane electrode assembly (1) having an anode (2), a cathode (3), and a hydrocarbon film (4) disposed between the anode (2) and the cathode (3). The membrane electrode assembly (1) further has a protective layer (5) disposed between the anode (2) and the hydrocarbon film (4) and / or between the cathode (3) and the hydrocarbon film (4), the protective layer (5) comprising at least one ceramic material (6) and at least one fluorine-containing ionomer (7), wherein the ceramic material (6) is dispersed in the fluorine-containing ionomer (7).

Description

[Technical Field]

[0001] The present invention relates in particular to a membrane electrode assembly usable in a proton exchange membrane fuel cell and a proton exchange membrane water electrolysis cell, as well as to a fuel cell and electrolysis cell equipped with the membrane electrode assembly. Furthermore, the present invention also relates to a method for manufacturing a membrane electrode assembly. [Background technology]

[0002] Fuel cells typically operate by supplying hydrogen to the anode and oxygen (air) to the cathode, producing water and electricity (and a certain amount of heat). On the cathode side of the catalytic coating film (CCM), oxygen is reduced to produce water, while on the anode side, hydrogen is oxidized to protons, moves through the film to the cathode side, and reacts with oxygen according to the following reaction equation. (Cathode) 1 / 2O2+2H + +2e - →H2O (Anode) H2→2H + +2e -

[0003] In the electrolysis of water, the reaction is reversed. That is, water and electric current are supplied to the cell, and hydrogen and oxygen are produced according to the following reaction equation. (Cathode) 2H + +2e - →H2 (Anode) H2O→1 / 2O2+2H + +2e -

[0004] The most commonly used catalysts for electrodes and applications include oxygen reduction (ORR) catalysts such as carbon-supported platinum or platinum alloys for the cathode of fuel cells, hydrogen oxidation (HOR) catalysts such as carbon-supported platinum (Pt / C) for the anode of fuel cells, hydrogen evolution (HER) catalysts such as carbon-supported platinum for the cathode of water electrolysis cells, and oxygen evolution (OER) catalysts such as unsupported iridium oxide or iridium-ruthenium mixed oxides for the anode of water electrolysis cells.

[0005] The catalyst metal type and support described above are selected considering optimal electrocatalytic activity and sufficient stability. Optimal electrocatalytic activity means the overpotential is as low as possible for the reaction to proceed at an appropriate rate. Sufficient stability means minimal corrosion or dissolution in the cell environment over the required lifespan for the application.

[0006] In the case of a water electrolysis cell, hydrogen generation is a simple reaction on platinum and occurs at very low overpotentials. That is, the cathode voltage of a water electrolysis cell remains close to zero (relative to a reversible hydrogen electrode: RHE) under normal operation. At this low potential, carbon is stable and can be used as a catalyst support.

[0007] Oxygen evolution at the anode occurs at a potential exceeding the thermodynamic potential for water splitting, which is 1.23V relative to RHE. Typical anode potentials due to reaction overpotential are far above this value, usually between 1.5V and 2.0V. In this voltage range, carbon is unstable and oxidizes over long periods. Therefore, it is not used as a catalyst support on the anode side, nor in other parts of the cell on the anode side (such as the transport layer or cell plate).

[0008] In fuel cells, reaction overpotentials cause the reduction of oxygen to occur at a voltage lower than the thermodynamic potential of the reaction in which hydrogen and oxygen become water; i.e., less than 1.23V relative to RHE, in contrast to the electrolysis of water. Therefore, the typical cathode potential is between 0.6V and 1.0V. At these potentials, the carbon support is stable and can be used to enhance catalytic activity.

[0009] When a suitable catalyst is used on the anode side, for example, a platinum-based catalyst dispersed on a carbon support with a large surface area, hydrogen oxidation is very efficient and proceeds easily at very low overpotentials. This means that the anode voltage can be kept very close to zero relative to the RHE. This is true in normal operation.

[0010] However, in a fuel cell stack, one or more cells may sometimes experience a situation where they run out of hydrogen at the anode during startup, under low temperature and wet conditions, or during a rapid transition. This means that the hydrogen necessary to maintain the stack current and supply sufficient electrons is not supplied to the anode. A reverse voltage (voltage reversal) occurs in the affected cells due to this situation.

[0011] In such a cell reversal (CR) state, the anode voltage rises to a value far exceeding the cathode voltage, for example, 1.5 V or more with respect to RHE, and the anode side of the cell may rapidly corrode and fail. Corrosion, that is, oxidation of carbon, compensates for the aforementioned shortage of electrons. Usually, the anode component most strongly affected by corrosion is the carbon support of the catalyst.

[0012] Furthermore, especially under start-up / shut-down (SUSD) operating conditions, a potential rise of 1.5 V or more with respect to RHE occurs on the cathode side. At this time, when the fuel cell is started, since the anode is filled with air, that is, oxygen, when hydrogen flows into the anode, a so-called hydrogen-air interface is formed. At this hydrogen-air interface, in addition to the oxidation of hydrogen on the anode, reduction of oxygen occurs, which is linked to the oxidation reaction on the cathode side. Usually, the cathode component most strongly affected by oxidation and corrosion is the carbon support of the catalyst.

[0013] The carbon supports on the anode side and the cathode side are oxidized according to the following reaction. (Anode of a fuel cell in a cell reversal state or cathode in an SUSD state) C + 2H2O → CO2 + 4H + + 4e - <了 (注:原日文此处有误,推测为 ,按照原样保留)

[0014] A failure of the fuel cell occurs when the corrosion of carbon progresses to such an extent that it significantly impairs the performance of the CCM under normal hydrogen supply conditions. Without appropriate mitigation measures, anode failure under cell reversal usually occurs in a very short time of tens of seconds to several minutes.

[0015] To protect the carbon of the anode electrode and / or the cathode electrode from corrosion under cell reversal and / or SUSD conditions, a common technical solution is usually to add a catalyst for the oxygen evolution reaction (OER) that is homogeneously mixed with a hydrogen oxidation catalyst (anode) and an oxygen reduction catalyst (cathode) to the electrode. The presence of such a catalyst (usually iridium oxide-based) enables the oxidation of water at the electrode at a higher rate than the corrosion of carbon, and according to the following reaction, the oxidation of water is prioritized over the oxidation of carbon. (Anode electrode during cell reversal and / or cathode electrode during SUSD) 2H2O→O2+4H + +4e -

[0016] In this way, during cell reversal, the cell operates like an electrolytic cell where air (oxygen) is reduced at the cathode and water is oxidized to oxygen at the anode.

[0017] Therefore, since the cell current is maintained by the oxidation of water rather than the corrosion of carbon, the anode can maintain the cell reversal state for a longer time, and the cathode can maintain startup and shutdown for a longer time. Due to the water oxidation reaction, the increase in the anode potential is limited to a value of 1.6 to 2 V with respect to RHE, so the carbon corrosion rate is also limited. That is, carbon corrosion still occurs, but at a much lower rate than when the voltage is not adjusted by the presence of the OER catalyst. Applying such a protection strategy allows the CCM to withstand cell reversal states lasting from several tens of minutes to several tens of hours.

[0018] From the above description, it can be seen that the anode of a water electrolysis cell usually operates at a high potential of 1.5 V to 2.0 V. However, the anode of a fuel cell may also be exposed to a similarly high potential (cumulatively) over a long period due to hydrogen deficiency.

[0019] Furthermore, hydrocarbon-based, so-called hydrocarbon membranes are known for use in fuel cells and water electrolysis cells. In this case, the structure of the ionomer (i.e., proton-conducting polymer) contained in the membrane does not contain fluorine, or contains only a limited amount of fluorine, up to 5% by mass relative to the mass of the ionomer used.

[0020] Compared to perfluorosulfonic acid (PFSA) membranes, hydrocarbon membranes offer several advantages. For example, their low gas permeability results in very low ionic resistance (and therefore superior performance), allowing for higher cell current yields even with very thin membranes. Furthermore, their low gas permeability (even at high temperatures) and the high glass transition temperature typical of hydrocarbon polymers allow for long-term use at temperatures above 100°C with limited degradation. High-temperature operation offers several system advantages, including smaller cooling systems, reduced sensitivity to gas contamination, and improved cell efficiency. Hydrocarbon membranes also release fewer aggressive decomposition products, such as HF and superacidic sulfonic acid molecules, which are emitted from PFSAs, resulting in less damage to metal bipolar plates in the stack during operation, extending their lifespan and allowing for the use of less expensive materials. Finally, hydrocarbon membranes are environmentally friendly compared to perfluoroinomers because they do not contain perfluoroalkyl compounds and their manufacture does not require perfluoroalkyl chemicals.

[0021] On the other hand, the inventors discovered that hydrocarbon films have insufficient electrochemical stability at high potentials typically used in water electrolysis anodes, or under cell inversion conditions for fuel cell anodes or SUSD conditions for fuel cell cathodes, i.e., voltages above 1.5V. At such high potentials, hydrocarbon films become susceptible to oxidation and damage, leading to performance degradation and CCM failure.

[0022] Therefore, the stability of CCMs (generally membrane electrode assemblies: MEAs) containing hydrocarbon films needs to be improved for use under conditions where the anode or cathode is continuously or intermittently exposed to high potential for extended periods. [Overview of the Initiative] [Problems that the invention aims to solve]

[0023] Therefore, an object of the present invention is to provide a MEA comprising a hydrocarbon film that is better protected from corrosion and associated oxidation, and as a result has a longer lifespan. Furthermore, an object of the present invention is to provide a fuel cell or water electrolysis cell with an extended lifespan due to reduced corrosiveness and oxidativeness by using a membrane electrode assembly according to the present invention. Furthermore, an object of the present invention is to provide a method for manufacturing a membrane electrode assembly with reduced corrosion and oxidation tendencies. [Means for solving the problem]

[0024] These challenges are addressed by the features of the independent claims. The dependent claims include advantageous improvements and configurations of the present invention.

[0025] These problems are solved by a membrane electrode assembly (MEA) further comprising an anode, a cathode, a hydrocarbon film disposed between the anode and the cathode, and a protective layer disposed between the anode and the hydrocarbon film and / or between the cathode and the hydrocarbon film.

[0026] The hydrocarbon film comprises at least one ionmer that is unfluorinated or has a fluorine content of up to 5% by mass relative to the total mass of the ionmers.

[0027] The protective layer comprises at least one ceramic material and one fluorine-containing ionomer, wherein the ceramic material is dispersed within the fluorine-containing ionomer. That is, the protective layer may consist of a single ceramic material or a mixture of multiple ceramic materials. The same applies to the fluorine-containing ionomer; that is, the protective layer may consist of a single fluorine-containing ionomer or a mixture of two or more fluorine-containing ionomers. The fluorine-containing ionomer may be partially fluorinated or fully fluorinated, or a mixture of partially fluorinated and / or fully fluorinated ionomers may be used. Fluorinated ionomers are well known to those skilled in the art, for example, under trade names such as Nation (The Chemours Company), Forblue i-series (AGC Inc.), or Aquivion (Solvay). The side chain structure may have a different number of CF2 groups or a branched structure, and is not limited in detail.

[0028] The ceramic material is not limited in detail, but preferably has electrical non-conductive properties and is dispersed in a fluorine-containing ionomer. This can be achieved, for example, in the manufacture of a protective layer by thoroughly mixing the ceramic material and the fluorine-containing ionomer before preparing the protective layer dispersion and performing further processing on the protective layer. Electrically non-conductive properties refer to a specific conductivity of 10 -3 This refers to materials with a conductivity of less than S / m. Conductivity is measured for powder under a compression of 50 MPa.

[0029] By using a protective layer containing at least one ceramic material and at least one fluorine-containing ionomer between the hydrocarbon film and the anode and / or cathode, it was confirmed that the MEA, particularly the hydrocarbon film, is protected from oxidation and corrosion, and that the MEA itself does not degrade even when high potentials persist on the anode or cathode side. As a result, the performance of the MEA covered with the protective layer is not impaired.

[0030] When exposed to high anode or cathode potentials exceeding 1.5V, oxidation of the hydrocarbon film in an MEA without the protective layer according to the present invention can be confirmed by the presence of a strong CO2 signal at the cell's anode or cathode output. The inventors have found that this signal is suppressed in the presence of the protective layer. This indicates that the hydrocarbon film is substantially unoxidized. This supports the effectiveness of the present invention's approach to solving the aforementioned problem.

[0031] Without being bound by theory, the hydrocarbon film within the MEA according to the present invention is assumed to be resistant to oxidation because the protective layer reduces the potential of the film surface to a value lower than the potential of the anode or cathode. To maximize this effect, the ceramic material is preferably non-conductive. Furthermore, it is believed that the hydrocarbon film is further protected from oxidative degradation by avoiding contact between the film surface and the electrode catalyst material. The protective layer is very stable due to the stable materials that constitute it, and therefore does not degrade due to high potential or contact with the catalyst of the electrode layer, thus protecting the hydrocarbon film from oxidation.

[0032] As a further advantageous improvement, the protective layer does not contain metal-containing catalysts in order to maximize its corrosion-preventive effect.

[0033] Hydrocarbon ion exchange resins and hydrocarbon membranes using them are not particularly limited.

[0034] Hydrocarbon ionomers, or hydrocarbon films made from them, are preferably of the sulfonated type. Sulfonated hydrocarbon ionomers are typically classified into sulfonated polystyrene copolymers (SPS), sulfonated polyimides (SPI), sulfonated polyphenylenes (SPP), sulfonated polyarylene polymers, or sulfonated polyphosphazenes (SPPh). Examples of hydrocarbon ion exchange resins belonging to these classifications include the following:

[0035] Sulfonated polyaryl ether (SPAE), sulfonated polyaryl ether nitrile (SPAEEN), sulfonated polyaryl ether ketone (SPAEK), sulfonated polyaryl ether nitrile (SPAEN), sulfonated polyaryl ether sulfone (SPAES), sulfonated polyaryl ether sulfone ketone (SPAESK), sulfonated polyether ether ketone (SPEEK), sulfonated polyether ketone (SPEK), sulfonated polyether sulfone (SP Examples include ES, sulfonated polyimide (SPI), sulfonated polyketone ketone (SPKK), sulfonated polyphosphazene (SPPh), sulfonated polyphenylene sulfone (SPPSf), sulfonated polyphenylene sulfide sulfone (SPPSSff), sulfonated polyphenylene sulfide sulfone nitrile (SPPSSfN), sulfonated polystyrene (SPS), sulfonated polysulfone (SPSf), sulfonated polyphenylene (sPP), and sulfonated phenylated polyphenylene (sPPP).

[0036] Particularly stable hydrocarbon films may be selected from sulfonated polyether ketones, sulfonated polyether ether ketones, sulfonated polyketone ketones, sulfonated polyphenylenes, sulfonated phenylated polyphenylenes, and mixtures thereof.

[0037] Hydrocarbon ion polymers may be linear polymers, crosslinked polymers, branched polymers, graft polymers, and / or block polymers. They may also contain heteroatoms such as F, N, S, and P, as needed. Block copolymers in which sulfonic acid-rich blocks and sulfonic acid-poor or unsulfonated blocks are alternately linked are particularly advantageous in that they combine high proton conductivity, excellent mechanical properties, and high dimensional stability.

[0038] Furthermore, it has been found that the presence of ceramic material in the protective layer not only provides high oxidation stability to the MEA, but also ensures excellent adhesion between the protective layer and the hydrocarbon film. As a result, the hydrocarbon film itself, and consequently the entire MEA, can maintain its integrity even under dynamic relative humidity conditions (alternating wetting and drying) and conditions in which the cell operates at wet and high temperatures, such as in a water electrolysis cell. To achieve such excellent adhesion, it is desirable that the total volume of ceramic material in the protective layer be at least 17 volume%, particularly at least 25 volume%, and even more particularly at least 30 volume%, relative to the total volume of the protective layer. Here, the total volume of the protective layer is defined as the sum of the volumes of the individual components. The smaller the total volume of ceramic material, the lower the compatibility between the (total) fluorinated ionomer and the hydrocarbon ionomer of the hydrocarbon film, making the protective layer more likely to peel off from the hydrocarbon film and degrading the performance of the MEA.

[0039] To achieve excellent proton conductivity obtained from a sufficient amount of fluorinated ionomer while ensuring sufficient adhesion, it is desirable that the total volume of ceramic material in the protective layer not be excessive. Furthermore, if the ceramic material content is particularly high, the protective layer may become brittle and mechanically unstable. Therefore, it is preferable that the total volume of ceramic material in the protective layer be less than 76 volume%, particularly less than 65 volume%, and even more particularly less than 54 volume%, relative to the total volume of the protective layer.

[0040] The particularly suitable volume ranges for ceramic materials are 17–76 vol%, 25–65 vol%, and especially 30–54 vol%.

[0041] The optimal volume of ceramic material in the protective layer is determined by considering the above requirements, starting with a low amount of ceramic material and increasing it by, for example, 5 volume% increments, to provide a minimum amount C that offers good adhesion. c_min This can be determined by optimization by finding the point C at which the MEA ion resistance due to the protective layer begins to increase measurably. c_maxThe amount of ceramic material can be further increased until (for example, the good adhesion is increased by more than 5% from the value initially confirmed). Optimal amount of ceramic material C c_opt C c_min and C c_max It lies between these two values. Generally, the optimal volume ratio of ceramic materials is determined by the chemical properties of the ceramic material, its specific surface area (e.g., BET, i.e., DIN ISO 9277:2003-05 "Measurement of the specific surface area of ​​solid materials by gas adsorption by the BET method"), and the method used to mix the ceramic material with the fluorinated ionomer.

[0042] The good adhesion between the hydrocarbon film and the protective layer, and generally between each layer of the MEA, can be confirmed by immersing the MEA in boiling water for an extended period (e.g., 4 hours) and visually observing the MEA. If the adhesion is good, the MEA will maintain its integrity; that is, the layers will not separate, nor will other small components separate from the MEA.

[0043] According to favorable further developments, the specific surface area of ​​ceramic materials measured by BET (based on DIN ISO 9277:2003-05 "Measurement of specific surface area of ​​solid materials by gas adsorption method BET") is 5-800 m². 2 / g, especially 20-500m 2 The value is / g. Ceramic materials with a specific surface area within the above range disperse very well in fluorinated ionomers.

[0044] Ceramic materials that are stable with respect to hydrogen at low potentials are preferable. In other words, it is desirable that the ceramic material in the protective layer be reduction-stable at low potentials (close to zero) and in the presence of hydrogen. In fact, especially in fuel cell applications, the anode is exposed to a low potential in a hydrogen environment for most of the time (during normal operation). However, even in water electrolysis cells, the anode may be exposed to a low potential when stopped, and hydrogen may migrate from the cathode to the anode. Therefore, if a ceramic material that is not stable with respect to hydrogen at low potentials is used, the metal will be reduced and gradually dissolve, and the protective layer will lose its function over time. In water electrolysis cell applications, this requirement is not as strict because the anode is not exposed to low potentials very often. Furthermore, it is possible to develop a shutdown strategy (e.g., passing a very small current from the stack) that completely prevents such conditions from occurring at the anode. Therefore, considering the excellent reduction stability, it is desirable that the weight loss of the ceramic material be less than 2 mass% when exposed to a 3.3 volume% hydrogen stream in argon at a temperature of 80°C for 12 hours.

[0045] Furthermore, ceramic materials selected from at least one of oxides, nitrides, carbides, silicides, borides, and mixtures thereof are also advantageous. Oxides, nitrides, carbides, silicides, and borides are not limited individually. However, oxides, nitrides, carbides, silicides, and borides are preferred. Due to their excellent reduction stability, these ceramic materials are particularly selected from Nb2O5, Ta2O5, SiO2, WO3, ZrO2, and mixtures thereof.

[0046] Furthermore, from the viewpoint of minimizing additional proton resistance due to MEA, the equivalent weight of the proton-conducting polymer in the protective layer can be less than 1050 g / mol, preferably less than 950 g / mol, and more preferably less than 850 g / mol. Here, the equivalent weight represents the weight of the ionomer per mole of the functional group, particularly the sulfonic acid group.

[0047] The thickness of the protective layer may be further adjusted or selected from the viewpoint of minimizing additional proton resistance due to MEA. The lower limit of the layer thickness is not particularly limited, as long as a defect-free layer of controlled thickness is manufactured. The thickness of the protective layer is preferably 0.1 μm or more, more preferably 0.15 μm or more, and even more preferably 0.2 μm or more. Importantly, the layer should be continuous, i.e., closed, i.e., free from cracks or defects. The layer thickness can be measured using a scanning electron microscope.

[0048] To achieve the lightweight structure and minimal additional proton resistance of the MEA, it is desirable that the thickness of the protective layer not be too large, especially less than 10 μm, even more specifically less than 5 μm, and even more specifically less than 3 μm.

[0049] The most advantageous protective layer thicknesses are in the range of 0.1–10 μm, particularly 0.2–5 μm, and even more particularly 0.5–3 μm.

[0050] The cathode contains at least one catalyst that catalyzes the cathode reaction. Preferably, the cathode contains at least one platinum-containing catalyst, and the amount of catalyst packed into the cathode is expressed as the weight of platinum per unit area of ​​the cathode, particularly 0.02 to 1 mg Pt / cm². 2 In particular, 0.05 to 0.6 mg Pt / cm 2 Furthermore, especially 0.1 to 0.4 mg Pt / cm 2 The platinum-containing catalyst may be platinum or a platinum alloy.

[0051] A particularly advantageous feature for improving the efficiency of the cathode reaction is that the cathode is supported with a platinum-containing catalyst, and the support for the platinum-containing catalyst preferably contains carbon.

[0052] To ensure the efficiency of the MEA in the case of water electrolysis, or to improve durability in the case of fuel cells, the anode includes at least one oxygen-evolving catalyst (OER catalyst).

[0053] Due to their excellent catalytic activity and stability against dissolution during operation, OER catalysts include iridium oxide or iridium / ruthenium mixed oxides in particular. Alternatively, the OER catalyst may be supported on a base metal oxide, which is preferably titanium oxide or niobium oxide. In this invention, a base metal means a metal with a standard potential of less than 0.7V to RHE.

[0054] From the perspective of improving the efficiency of MEA, a further advantageous improvement is to include a hydrogen oxidation reaction catalyst (HOR catalyst), particularly a platinum-containing HOR catalyst, in the anode. The amount of platinum-containing HOR catalyst packed into the anode should be 0.01 to 0.2 mg Pt / cm² in terms of platinum weight per unit area of ​​the anode. 2 , especially 0.03 to 0.1 mg Pt / cm 2 A particularly advantageous feature is that the HOR catalyst is supported on a carbon-containing carrier.

[0055] The membrane electrode assembly is preferably formed as either a fuel cell membrane electrode assembly or a water electrolysis cell membrane electrode assembly.

[0056] When the MEA is configured as a water electrolysis cell membrane electrode assembly, the amount of catalyst packed into the anode is preferably 0.05 to 2 mgIr / cm², expressed as the weight of iridium per unit area of ​​the anode. 2 , especially 0.1 to 1.5 mg Ir / cm³ 2 Furthermore, especially 0.2 to 1 mg Ir / cm³ 2 It is preferable that this be the case.

[0057] When the MEA is configured as a fuel cell membrane electrode assembly, the amount of catalyst packed into the anode is preferably 0.005 to 0.05 mgIr / cm³, expressed as the weight of iridium per unit area of ​​the anode. 2 In particular, 0.006 to 0.03 mg Ir / cm³ 2 That is the case.

[0058] When the MEA is configured as a water electrolysis cell membrane electrode assembly, the layer thickness of the hydrocarbon membrane is preferably 150 μm or less.

[0059] Hydrocarbon films may have mechanical reinforcement, such as fibers or reinforcing structures. The reinforcing structure can be introduced, for example, during the manufacturing process of the hydrocarbon film from an ionomer dispersion or ionomer solution. In this case, ceramic materials, polymer materials such as (biaxially oriented) PTFE (ePTFE: expanded PTFE), or woven structures such as polyketone (PK) fibers, polyetherketone (PEK) fibers, polyetheretherketone (PEEK) fibers, perfluoroalkoxyalkane (PFA) fibers, or polyphenylene sulfide (PPS) fibers are impregnated with the corresponding ionomer dispersion, then dried, so that the pores of the reinforcing structure are filled with ionomer. In this case, the hydrocarbon film has mechanical reinforcement, and the thickness of the hydrocarbon film is preferably 20-120 μm, particularly 30-100 μm.

[0060] When the MEA is formed as a fuel cell membrane electrode assembly, the layer thickness of the hydrocarbon membrane is preferably 20 μm or less.

[0061] Hydrocarbon membranes may have mechanical reinforcement, such as fibers or reinforcing structures. The reinforcing structure can be introduced, for example, during the hydrocarbon membrane manufacturing process from an ionomer dispersion or ionomer solution. In this case, ceramic materials, polymer materials such as (biaxially oriented) PTFE (ePTFE: expanded PTFE), or woven structures such as polyketone (PK) fibers, polyetherketone (PEK) fibers, polyetheretherketone (PEEK) fibers, perfluoroalkoxyalkane (PFA) fibers, or polyphenylene sulfide (PPS) fibers are impregnated with the corresponding ionomer dispersion, then dried, so that the pores of the reinforcing structure are filled with ionomer. In this case, the hydrocarbon membrane of the fuel cell membrane electrode assembly has mechanical reinforcement, and the layer thickness of the hydrocarbon membrane is preferably 5 to 15 μm.

[0062] If necessary, additional layers can be inserted between the protective layer and the anode, or between the protective layer and the cathode.

[0063] Furthermore, water electrolytic cells and fuel cells including the membrane electrode assembly according to the present invention will also be described. By using the membrane electrode assembly according to the present invention, corrosion and oxidation of the MEA are reduced, thus improving the lifespan of the water electrolytic cells and fuel cells. The water electrolytic cells and fuel cells are, in particular, PEM water electrolytic cells or PEM fuel cells.

[0064] The advantageous improvements to the membrane electrode assembly according to the present invention also apply to the fuel cell and water electrolysis cell according to the present invention.

[0065] Furthermore, the present invention also describes a first method for manufacturing the membrane electrode assembly disclosed above. This method first comprises the step of manufacturing a protective layer dispersion comprising at least one ceramic material and at least one fluorine-containing ionomer, as described above for the MEA of the present invention. The ceramic material and ionomer are dispersed or suspended in a liquid medium such as, for example, a polar organic solvent, a mixture of polar organic solvents, water, or preferably a mixture of water and one or more polar organic solvents. Non-limiting examples of polar organic solvents include acetone, acetonitrile, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), 1-propanol, 2-propanol, ethanol, 1-butanol, or tert-butyl alcohol.

[0066] To produce a protective layer dispersion, ceramic material and fluorine-containing ionomer can be ground using a ball mill (grinding medium: ZrO2 spheres). The grinding time is, for example, 120 minutes, but can be adjusted according to the dispersibility of the ceramic material.

[0067] Alternatively, ultrasonic devices and various grinding machines can be used to produce dispersions. Examples include ball mills, agitated bead mills, agitated mills, attritors, and certain rolling mills.

[0068] In the following explanation, the term "electrode" refers to both the anode and cathode in the case of fuel cells, and specifically refers only to the anode in the case of water electrolysis. This is because high potentials of 1.5V or more can occur at these electrodes, where a protective layer may have a beneficial effect.

[0069] In the next step, the protective layer dispersion is applied to the electrode or hydrocarbon film. Common techniques such as slit dies, doctor blades, spiral applicators, screen printing, or spray equipment are particularly used.

[0070] Subsequently, the protective layer dispersion is dried on the electrode or hydrocarbon film while maintaining the protective layer.

[0071] If the protective layer dispersion is applied to the electrode, a further step may be taken to laminate the electrode with the protective layer and the hydrocarbon film. The lamination temperature is preferably 150 to 190°C, and the pressure is preferably 1 to 3 MPa. The lamination time is preferably about 1 minute.

[0072] The above method also applies when the protective layer dispersion is applied to a hydrocarbon film. Lamination (layering) with the electrode is then performed.

[0073] The first method according to the present invention can be easily carried out using conventional techniques and enables the production of MEA with high oxidation stability and corrosion resistance.

[0074] In the second method according to the present invention, the production of the MEA according to the present invention begins with the production of a protective layer dispersion, which can be carried out in the same manner as in the first method. The protective layer dispersion comprises at least one ceramic material and at least one fluorine-containing ionomer.

[0075] Next, the protective layer dispersion is applied to the substrate. The substrate is inert to the protective layer dispersion and does not react with it chemically or physically.

[0076] In a further step, the protective layer dispersion is dried to form a protective layer, resulting in a so-called decal.

[0077] Subsequently, the protective layer is transferred to the electrode or hydrocarbon film, and the substrate is removed.

[0078] Depending on whether the protective layer is transferred to the electrode or to the hydrocarbon film by a decal method, lamination with either the hydrocarbon film or the electrode can be performed in the same manner as described in the first invention.

[0079] This second invention also allows for the easy implementation of conventional techniques and enables the production of MEA with high oxidation and corrosion stability.

[0080] In the third method according to the present invention, as described above, first, a protective layer dispersion containing at least one ceramic material and at least one fluorine-containing ionomer is prepared.

[0081] Furthermore, an electrode dispersion is manufactured. The electrode dispersion contains at least one catalytically active substance, as described in particular for the MEA according to the present invention.

[0082] Next, the decal method is performed, where the electrode dispersion is first applied to the electrode dispersion coated on the substrate, followed by the protective layer dispersion. This creates a layered structure of substrate / electrode dispersion / protective layer dispersion.

[0083] Then, the dispersion is dried. There is no specific order to follow. For example, the electrode dispersion can be dried or partially dried first, and then the protective layer dispersion can be applied. Alternatively, the protective layer dispersion can be applied over the electrode dispersion, which is still wet or not completely dry, and both dispersions can be dried simultaneously on the substrate while forming the electrode layer and the protective layer.

[0084] Next, the decal, i.e., the dried electrode layer / protective layer assembly, is transferred to the hydrocarbon film so that the protective layer is positioned between the hydrocarbon film and the electrode.

[0085] This third method according to the present invention allows for the easy production of MEA with high oxidation and corrosion stability using conventional techniques.

[0086] In the third method according to the present invention, the lamination process of the electrode layer / protective layer assembly and the hydrocarbon film can be continued in the above step, similar to the first and second methods according to the present invention.

[0087] In the fourth method according to the present invention, as described above, first, a protective layer dispersion containing at least one ceramic material and at least one fluorine-containing ionomer is prepared.

[0088] Furthermore, an electrode dispersion (anodic dispersion or cathode dispersion) is prepared. The electrode dispersion contains at least one catalytically active substance, as described in particular for the MEA according to the present invention.

[0089] Next, the protective layer dispersion is applied onto the hydrocarbon film, followed by the electrode dispersion being applied onto the protective layer dispersion.

[0090] Furthermore, the dispersion is dried while forming the electrode layer and protective layer. The dispersion can be dried sequentially or simultaneously.

[0091] The fourth method according to the present invention also realizes MEA with improved oxidation and corrosion stability, and this method can be easily carried out using conventional techniques.

[0092] If the MEA to be manufactured is a fuel cell membrane electrode assembly, the following fifth method according to the present invention can also be applied.

[0093] In the first step, as with all the methods described above, a protective layer dispersion containing at least one ceramic material and at least one fluorine-containing ionomer is prepared. Similarly, an electrode dispersion is also prepared.

[0094] Next, the electrode dispersion (anodic dispersion or cathode dispersion) is applied to the gas diffusion layer, and then the protective layer dispersion is applied to the electrode dispersion.

[0095] Furthermore, the dispersion is dried while forming the electrode layer and protective layer. The dispersion can be dried sequentially or simultaneously.

[0096] Next, the protective layer, electrode layer, and gas diffusion layer are arranged on the hydrocarbon film, and the lamination process can be continued in the same manner as described above.

[0097] In another step of the fifth method, the protective layer dispersion is applied onto the hydrocarbon film. In yet another step, the protective layer dispersion is dried to form the protective layer. Subsequently, the electrode layer / gas diffusion layer assembly is placed on the protective layer / hydrocarbon film assembly, and the lamination process can be carried out in the same manner as described above.

[0098] The fifth method according to the present invention also realizes MEA with improved oxidation and corrosion stability, and this method can be easily implemented using conventional techniques.

[0099] All of the above methods may be followed by an additional step of annealing at a temperature range of 150-200°C to enhance the mechanical properties of the protective layer. This step can also be performed in conjunction with the decal method.

[0100] In all of the above methods, the counter electrode can be provided as a decal, direct coating, or gas diffusion electrode. In this case, the anode and cathode methods can be combined independently of each other.

[0101] The production of MEA by the method according to the present invention can be easily and with high productivity using state-of-the-art technologies and equipment already used in the production of fuel cell membrane electrode assemblies and water electrolysis cell membrane electrode assemblies.

[0102] Details, advantages, and features of the present invention will become clear from the description of the embodiments with reference to the drawings. The drawings are shown below. [Brief explanation of the drawing]

[0103] [Figure 1] Figure 1 is a cross-sectional view of an MEA according to the first embodiment. [Modes for carrying out the invention]

[0104] Figure 1 shows only the main components of the MEA. Other components have been omitted for clarity.

[0105] Figure 1 shows in detail the MEA1, which can be used in fuel cells or electrolytic cells.

[0106] The MEA1 is shown in cross-section and comprises an anode 2, a cathode 3, and a hydrocarbon film 4 positioned between the anode 2 and the cathode 3. A protective layer 5 is provided between the hydrocarbon film 4 and the anode 2 to protect the MEA1 from corrosion and oxidation processes.

[0107] This protection mechanism is seen, for example, when MEA is used in fuel cells. When a fuel cell operates under low temperature and humid conditions, or when a sudden change occurs in the fuel cell cell that leads to a hydrogen deficiency at the anode, the anode may not receive enough hydrogen to maintain the stack current and supply sufficient electrons, resulting in the affected cell entering a voltage inversion state. In such a cell inversion state, the anode voltage rises to a value significantly higher than the cathode voltage (e.g., 1.5V or more relative to RHE). This can cause rapid corrosion and failure of the anode side of the fuel cell, but this can be prevented by the MEA according to the present invention.

[0108] The above-mentioned advantageous effects are also observed when MEA is applied to a water electrolysis cell. Here, oxygen evolution occurs at the anode at a potential above 1.23V relative to the RHE, which is the thermodynamic potential for water decomposition. Due to reaction overpotential, the typical anode potential is far above this value, usually between 1.5V and 2.0V. In this voltage range, carbon is unstable and oxidizes over a long period of time. This oxidation process is also prevented by the MEA according to the present invention.

[0109] These unexpected beneficial effects are attributed to the structure of the MEA1 shown in Figure 1. Here, a protective layer 5 containing at least one ceramic material 6 and at least one fluorine-containing ionomer 7 is present between the hydrocarbon film 4 and the anode 3, with the ceramic material 6 dispersed in the fluorine-containing ionomer 7. The total amount of ceramic material 6 is in the range of 17 to 76 volume percent relative to the total amount of the protective layer 5.

[0110] The ceramic material 6 is preferably selected from at least one oxide, nitride, carbide, silicide, or boride selected from silicon, tantalum, niobium, zinc, titanium, zirconium, cerium, tungsten, antimony, or mixtures thereof, and mixtures thereof. Furthermore, the ceramic material 6 is particularly reductively stable to hydrogen. In this respect, it is preferably selected from Nb2O5, Ta2O5, SiO2, WO3, ZrO2, and mixtures thereof.

[0111] The equivalent weight of the proton-conducting polymer 7 is less than 1050 g / mol, particularly less than 950 g / mol, and even more particularly less than 850 g / mol. This ensures that even with a limited amount of ionmer, a sufficient number of proton-conducting sulfonic acid groups are present, resulting in high proton conductivity for the entire protective layer.

[0112] The thickness S of the protective layer 5 is in the range of 0.1 to 10 μm, which allows for particularly efficient protection with the smallest possible volume and weight.

[0113] The hydrocarbon film 4 particularly includes sulfonated polyether ketones, sulfonated polyether ether ketones, sulfonated polyketone ketones, sulfonated polyphenylenes, sulfonated phenylated polyphenylenes, and mixtures thereof.

[0114] Cathode 3 contains at least one platinum-containing catalyst, and the amount of catalyst packed into cathode 3 is particularly 0.02 to 1 mg Pt / cm² in terms of platinum weight per unit area of ​​cathode 3. 2 This may be the case, and the catalyst is particularly supported on a carbon-containing support.

[0115] Anode 2 also includes at least one catalyst, which comprises iridium oxide or an iridium / ruthenium mixed oxide, and is optionally supported on a base metal oxide, particularly titanium oxide or niobium oxide.

[0116] Furthermore, anode 2 contains a hydrogen oxidation reaction catalyst, particularly a platinum-containing hydrogen oxidation reaction catalyst, and the amount of platinum-containing hydrogen oxidation catalyst packed into anode 2 is, in terms of weight of platinum per unit area of ​​anode 2, particularly 0.01 to 0.2 mg Pt / cm². 2 That's fine.

[0117] In addition to the above description of the invention, please refer to the drawings of the invention shown in Figure 1 for supplementary disclosure.

[0118] Manufacturing of a membrane electrode device in the form of a catalyst-coated film (CCM) according to the present invention The catalyst coating (CCM) consists of an anode catalyst layer containing 50% by mass of Pt and a cathode catalyst layer containing 50% by mass of PtCo (platinum filling amount: 0.50 mg Pt / cm²). 2 The catalyst coating (CCM) was manufactured using the decal method (standard decal transfer method) by placing an ion exchange membrane between the anode layer and the cathode layer on the opposite side of the membrane. The effective area of ​​both catalyst layers was 71 mm × 62 mm, and the membrane size was 100 mm × 100 mm. Table 1 summarizes the composition of the CCM.

[0119] An anodic catalyst ink was prepared by mixing a Pt / C (50 wt Pt on carbon) catalyst and an iridium oxide catalyst with water, an organic solvent, and a Solvay Specialty Polymers D79-25BS PFSA ionomer dispersion. The mass ratio of platinum to iridium was 1:1. The mass ratio of ionomer to carbon was 0.8:1. The anodic catalyst ink was ground in a ball mill (grinding medium: 1 mm diameter ZrO2 spheres) for 120 minutes. The catalyst ink was applied to a substrate and dried (decal method) to produce an anodic catalyst layer.

[0120] The cathode catalyst ink was prepared by mixing a PtCo / C (50 wt% PtCo on carbon) catalyst, water, an organic solvent, and a Solvay Specialty Polymers D79-25BS PFSA iromer dispersion. The mass ratio of iromer to carbon was 1:1. The cathode catalyst ink was ground in a ball mill (grinding medium: 1 mm diameter ZrO2 spheres) for 120 minutes. The cathode catalyst layer was prepared by coating the catalyst ink onto a substrate and drying it (decal method).

[0121] [Example 1] (Hydroxide film with protective layer) To prepare the protective layer dispersion, 0.83 g of Nb2O5 (BET surface area 6.2 m²) 2 A mixture of 1.40 g of D79-25BS (Solvay's PFSA ionomer dispersion, 25% by mass) and 7.77 g of organic solvent was prepared and ground for 120 minutes using a ball mill (grinding medium: 1 mm diameter ZrCO2 spheres). The mass ratio of metal oxide to ionomer was 2.37:1. This corresponds to 52% by volume of niobium oxide. This conversion is based on the density of niobium oxide, which is 4.6 g / cm³. 3 and the density of the ionomer is 2.1 g / cm³. 3 The procedure was carried out using [a specific method]. Subsequently, the protective layer dispersion was coated onto the anode using a spiral scraper (wire diameter 4 μm) and dried in an oven at 120°C for 5 minutes. Scanning electron microscope measurements showed that the thickness of the protective layer was approximately 200 nm.

[0122] The anode and cathode layers were fabricated using the method described above. A 7 μm thick sPEEK type hydrocarbon film was used for the fabrication of the CCM. The hydrocarbon film was placed between the protective layer / anode assembly and the cathode, laminated at 160°C and 3 MPa for 1 minute, and then the substrate (decal) was removed.

[0123] [Example 2] (Hydroxide film with protective layer) To prepare the protective layer dispersion, 0.59 g of Nb2O5 (BET surface area 6.2 m²) 2 A mixture of 2.36 g of D79-25BS (Solvay's PFSA ionomer dispersion, 25% by mass) and 7.05 g of organic solvent was used, and the mixture was ground for 120 minutes using a ball mill (grinding medium: 1 mm diameter ZrO2 spheres). The mass ratio of metal oxide to ionomer was 1:1. This corresponded to 31% by volume of niobium oxide.

[0124] This conversion is based on the density of niobium oxide, which is 4.6 g / cm³. 3 and the density of the ionomer is 2.1 g / cm³. 3 The procedure was carried out using [a specific method]. Subsequently, the protective layer dispersion was coated onto the anode using a spiral squeegee (wire diameter 4 μm) and dried in an oven at 120°C for 5 minutes. Scanning electron microscope measurements showed that the thickness of the protective layer was approximately 200 nm.

[0125] The anode and cathode layers were manufactured according to the method described above. A 7 μm thick sPEEK type hydrocarbon film was used for the manufacture of the CCM. The hydrocarbon film was placed between the protective layer / anode assembly and the cathode, laminated at 160°C and 3 MPa for 1 minute, and then the substrate (decal) was removed.

[0126] [Comparative Example 1] (Hydroxide film) The anode and cathode layers were manufactured according to the above description. No protective layer was used. The same hydrocarbon film type (7 μm thick) as in Example 1 was used for the manufacture of the CCM.

[0127] [Comparative example 2] (PFSA membrane) The anode and cathode layers were fabricated in the same manner as described above. No protective layer was used. A 12 μm thick PFSA film was used for the fabrication of the CCM.

[0128] [Comparative Example 3] (Hydrogen film) The anode and cathode layers were prepared according to the method described above. A protective layer consisting solely of an ionomer was used. For this purpose, 1.40 g of D79-25BS (Solvay's PFSA ionomer dispersion, 25% by mass) was mixed with 7.77 g of an organic solvent. The protective layer dispersion was then coated onto the anode using a spiral squeegee (wire diameter 8 μm) and dried in an oven at 120°C for 5 minutes. As a result, the thickness of the protective layer was approximately 200 nm. For the preparation of the CCM, the same 7 μm thick hydrocarbon film as in Example 1 was used.

[0129] Fuel cell testing The electrochemical test was conducted using a 38 cm² flow plate equipped with a graphitized serpentine type flow plate. 2 The experiment was conducted using a single PEM cell. The cell's temperature was controlled by a thermocouple using a heat-resistant heat plate and a cooling fan. The gas was humidified using a humidifier (bubbler). The cell operated in a countercurrent configuration.

[0130] All manufactured CCMs had carbon-based gas diffusion layers on both sides of the membrane electrode unit (CCM). All CCM samples had incompressible PTFE seals reinforced with glass fibers that resulted in a 10 volume% compression of the GDL. Before conducting fuel depletion tests on the MEA samples, the single cells were rated at 1 A / cm². 2 , pressure 1.5 bar abs The cells were conditioned in hydrogen / air for 8 hours. The temperature of the single cell was T cell The temperature was 80°C, and the humidifier temperatures were 80°C (anode) and 80°C (cathode).

[0131] Fuel depletion test (cell inversion) The cells were subjected to an extended reversal test, in which a current of 0.2 A / cm² was applied while the fuel cell was operated with air on the cathode side and nitrogen on the anode side (simulating a fuel depletion state). The test was terminated when the average cell voltage dropped to below -1.5V. The time required to reach -1.5V was quantified as the extended reversal tolerance time.

[0132] Carbon dioxide (CO2) content was measured at the anode outlet using a Binos 100 2M sensor from Fisher-Rosemont GmbH & Co (Germany). This measurement principle is based on the use of a non-dispersive infrared (NDIR) photometer.

[0133] Adhesion test To measure adhesion, a full-face CCM (Cambodia Compressor) was fabricated, i.e., a 50 x 50 mm specimen with the anode and cathode the same size as the film, and immersed in boiling water for 4 hours. If adhesion was good, the bond between both electrodes and the film was maintained; if adhesion was poor, one or both electrodes peeled off from the film.

[0134] In the fuel cell configuration, Example 1, which included the protective layer according to the present invention between the anode and the membrane, showed a significant improvement in cell inversion tolerance compared to a CCM using a hydrocarbon membrane without such a protective layer (Comparative Example 1). Furthermore, Example 1 showed the same level of cell inversion tolerance as a corresponding CCM with a PFSA membrane without the protective layer according to the present invention. Comparative Example 3 had a protective layer without ceramic components between the anode and the membrane. Due to poor adhesion between the hydrocarbon membrane and the PFSA protective layer, it was not possible to measure the cell inversion strength.

[0135] [Table 1] [Explanation of Symbols]

[0136] 1. Membrane electrode assembly 2 Anode 3 cathode 4. Hydrocarbon film 5 Protective layer 6. Ceramic Materials 7 Fluorinated ionomers S Protective layer thickness

Claims

1. A membrane electrode assembly (1) comprising an anode (2), a cathode (3), and a hydrocarbon film (4) disposed between the anode (2) and the cathode (3), further comprising a protective layer (5) disposed between the anode (2) and the hydrocarbon film (4) and / or between the cathode (3) and the hydrocarbon film (4), wherein the protective layer (5) comprises at least one ceramic material (6) and at least one fluorine-containing ionomer (7), and the ceramic material (6) is dispersed in the fluorine-containing ionomer (7).

2. The hydrocarbon film (4) comprises and / or sulfonated polyether ketone, sulfonated polyether ether ketone, sulfonated polyketone ketone, sulfonated polyphenylene, sulfonated phenylated polyphenylene, and mixtures thereof. The total volume of the ceramic material (6) in the protective layer (5) is at least 17 volume%, particularly at least 25 volume%, and more particularly at least 30 volume%, and / or The total volume of the ceramic material (6) in the protective layer (5) is less than 76 volume%, more particularly less than 65 volume%, and / or more particularly less than 54 volume%, relative to the total volume of the protective layer (6), and / or The specific surface area of ​​the ceramic material (6) is 5 to 800 m² when measured by the BET method. ２ / g, especially 20 to 500m ２ / g and / or The ceramic material (6) has a weight loss of less than 2 mass% when exposed to a 3.3 volume% hydrogen stream in argon at a temperature of 80°C for 12 hours, and / or The ceramic material (6) is selected from at least one oxide, nitride, carbide, silicide, boride, and mixtures thereof selected from silicon, tantalum, niobium, zinc, titanium, zirconium, cerium, tungsten, antimony, or mixtures thereof, particularly Nb ２ O ５ , Ta ２ O ５ , SiO ２ , WO ３ , ZrO ２ and mixtures thereof, and / or The equivalent amount of the proton-conducting polymer (7) in the protective layer is less than 1050 g / mol, more particularly less than 950 g / mol, and / or The thickness (S) of the protective layer (5) is less than 10 μm, particularly less than 5 μm, and even more particularly less than 3 μm, and / or The thickness (S) of the protective layer (5) is 0.1 μm or more, particularly 0.15 μm or more, and even more particularly 0.2 μm or more. The membrane electrode assembly (1) according to feature 1.

3. The cathode (3) contains at least one platinum-containing catalyst, and the amount of catalyst packed into the cathode (3) is, in particular, 0.02 to 1 mg Pt / cm², expressed as the weight of platinum per unit area of ​​the cathode (3). ２ In particular, 0.05 to 0.6 mg Pt / cm ２ Furthermore, especially 0.1 to 0.4 mg Pt / cm ２ The film electrode assembly (1) according to claim 1 or 2, wherein the catalyst is particularly supported, and the support for the catalyst particularly contains carbon.

4. The film electrode assembly (1) according to any one of claims 1 to 3, wherein the anode (2) comprises at least one oxygen-evolving catalyst, the oxygen-evolving catalyst particularly comprises iridium oxide or an iridium-ruthenium mixed oxide, and / or the oxygen-evolving catalyst is particularly supported on a base metal oxide, and more particularly supported on titanium oxide or niobium oxide.

5. The anode (2) further comprises a hydrogen oxidation reaction catalyst, particularly a platinum-containing hydrogen oxidation reaction catalyst, and the amount of platinum-containing hydrogen oxidation reaction catalyst packed into the anode (2) is, in terms of the weight of platinum per unit area of ​​the anode, particularly 0.01 to 0.2 mg Pt / cm². ２ , especially 0.03 to 0.1 mg Pt / cm ２ The film electrode assembly (1) according to any one of claims 1 to 4, wherein the hydrogen oxidation reaction catalyst is particularly supported on a carbon-containing support.

6. The membrane electrode assembly (1) according to any one of claims 1 to 5, characterized in that the membrane electrode assembly (1) is a water electrolysis cell membrane electrode assembly.

7. The membrane electrode assembly (1) according to any one of claims 1 to 5, characterized in that the membrane electrode assembly (1) is a fuel cell membrane electrode assembly.

8. The amount of catalyst packed into the anode (2) is expressed as the weight of iridium per unit area of ​​the anode (2), which is between 0.05 and 2 mgIr / cm². ２ In particular, 0.1 to 1.5 mg Ir / cm² ２ Furthermore, especially 0.2 to 1 mg Ir / cm² ２ The membrane electrode assembly (1) according to claim 6, which refers to feature 4.

9. The amount of catalyst packed into the anode (2) is 0.005 to 0.05 mgIr / cm², expressed as the weight of iridium per unit area of ​​the anode (2). ２ In particular, 0.006 to 0.03 mg Ir / cm² ２ The membrane electrode assembly (1) according to claim 7, which refers to feature 4.

10. The membrane electrode assembly (1) according to claim 6 or 8, characterized in that the layer thickness of the hydrocarbon film (4) is 150 μm or less, or the hydrocarbon film (4) has mechanical reinforcement and the layer thickness of the hydrocarbon film (4) is 20 to 120 μm, particularly 30 to 100 μm.

11. The membrane electrode assembly (1) according to claim 7 or 9, characterized in that the layer thickness of the hydrocarbon film (4) is 20 μm or less, or the hydrocarbon film (4) has mechanical reinforcement and the layer thickness of the hydrocarbon film (4) is 5 to 15 μm.

12. A water electrolysis cell comprising a membrane electrode assembly (1) according to any one of claims 1 to 6, 8, and 10.

13. A fuel cell comprising a membrane electrode assembly (1) according to any one of claims 1 to 5, 7, 9, and 11.

14. A method for manufacturing a membrane electrode assembly (1) according to any one of claims 1 to 11, A step of producing a protective layer dispersion containing at least one ceramic material (6) and at least one fluorine-containing ionomer (7), The steps include applying the protective layer dispersion to the anode (2), the cathode (3), or the hydrocarbon film (4), A step of drying the protective layer dispersion, wherein the protective layer (5) is obtained on the anode (2), the cathode (3), or the hydrocarbon film (4); A method for manufacturing a membrane electrode assembly (1) comprising the above.

15. A method for manufacturing a membrane electrode assembly (1) according to any one of claims 1 to 11, A step of producing a protective layer dispersion containing at least one ceramic material (6) and at least one fluorine-containing ionomer (7), The steps include: applying the protective layer dispersion onto the substrate; A step of drying the protective layer dispersion, wherein the protective layer (5) is manufactured, A step of transferring the protective layer (5) to the anode (2), the cathode (3), or the hydrocarbon film (4), A method for manufacturing a membrane electrode assembly (1) comprising the above.

16. A method for manufacturing a membrane electrode assembly (1) according to any one of claims 1 to 11, A step of producing a protective layer dispersion containing at least one ceramic material (6) and at least one fluorine-containing ionomer (7), A process for manufacturing an anodic dispersion or a cathode dispersion, A step of applying the anodic dispersion or the cathode dispersion onto a substrate, A step of applying the protective layer dispersion onto the anode dispersion or the cathode dispersion, A step of drying the dispersion, wherein the anode layer and the protective layer (5) are manufactured in the form of an anode layer / protective layer assembly, or the cathode layer and the protective layer (5) are manufactured in the form of a cathode layer / protective layer assembly, A step of transferring a dried anode layer / protective layer assembly or a cathode layer / protective layer assembly onto the hydrocarbon film (4), Equipped with, A method for manufacturing a membrane electrode assembly (1), optionally further comprising the step of laminating the anode layer / protective layer assembly and the hydrocarbon film (4).

17. A method for manufacturing a membrane electrode assembly (1) according to any one of claims 1 to 5, 7, 9, and 11, A step of producing a protective layer dispersion containing at least one ceramic material (6) and at least one fluorine-containing ionomer (7), A process for manufacturing an anodic dispersion or a cathode dispersion, A step of applying the anode dispersion or the cathode dispersion onto a gas diffusion layer, A step of applying the protective layer dispersion onto the anode dispersion or the cathode dispersion, A step of drying the dispersion, wherein the anode layer and the protective layer (5) are manufactured in the form of an anode layer / protective layer / gas diffusion layer assembly, or the cathode layer and the protective layer (5) are manufactured in the form of a cathode layer / protective layer / gas diffusion layer assembly, A step of placing a dried anode layer / protective layer / gas diffusion layer assembly, or a dried cathode layer / protective layer / gas diffusion layer assembly, on the hydrocarbon film (4) A method for manufacturing a membrane electrode assembly (1) comprising the above.

18. A method for manufacturing a membrane electrode assembly (1) according to any one of claims 1 to 5, 7, 9, and 11, A step of producing a protective layer dispersion containing at least one ceramic material (6) and at least one fluorine-containing ionomer (7), A process for manufacturing an anodic dispersion or a cathode dispersion, The steps include applying the protective layer dispersion onto the hydrocarbon film (4), A step of applying the anode dispersion or the cathode dispersion to the protective layer dispersion, A step of drying the dispersion, wherein the anode layer or the cathode layer and the protective layer (5) are manufactured, A method for manufacturing a membrane electrode assembly (1) comprising the above.

19. The method according to any one of claims 14 to 18, further comprising the step of annealing in a temperature range of 150 to 200°C.

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