Membrane electrode for low-humidity fuel cell and preparation method of membrane electrode

Abstract

The invention discloses a membrane electrode for a low-humidity fuel cell and a preparation method of the membrane electrode. The hydrophilic nanoparticles are mixed with the catalyst slurry in an atomized state and are immediately deposited and fixed, so that the agglomeration phenomenon of the hydrophilic nanoparticles in slurry mixing and storage stages is avoided, and nano-scale uniform dispersion in a three-dimensional space of a catalyst layer is realized. By independently controlling the conveying rate of the two fluids, the loading capacity and proportion of the hydrophilic nano-particles in the final catalyst layer can be accurately and flexibly regulated and controlled. According to the present invention, the uniformly dispersed hydrophilic nanoparticles construct the efficient hydrophilic channel, such that the water balance management ability of the catalyst layer is significantly improved, and particularly under the low humidity or starting working condition, the water can be effectively stored, the proton exchange membrane can be reversely wetted, and the membrane drying can be prevented so as to improve the battery performance;

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to a membrane electrode for low-humidity fuel cells and its preparation method. Background Technology

[0002] The membrane electrode assembly (MEA) is a core component of a fuel cell, and its performance directly affects the cell's energy conversion efficiency and stability. Proton conduction in the MEA relies on a continuous hydrogen bond network formed by water molecules absorbed within the membrane. The wetter the membrane, the more complete the hydrogen bond network, the higher the proton conductivity, the lower the cell's internal resistance, and the better its overall performance.

[0003] To improve system efficiency and simplify the structure (e.g., reducing or even eliminating complex humidification devices), fuel cells are expected to operate stably without external humidification or under low humidity conditions. However, under high temperature and low humidity conditions, the proton exchange membrane is prone to dehydration, leading to a sharp drop in proton conductivity, a significant increase in internal resistance, severe performance degradation, and even the potential for membrane perforation, resulting in permanent damage to the battery.

[0004] To address the aforementioned issues, a common strategy is to introduce hydrophilic nanoparticles, such as SiO2, TiO2, and Al2O3. These particles are rich in hydroxyl groups (-OH), which are strongly hydrophilic groups. They can strongly bind water molecules through physical adsorption and capillary condensation, thereby improving the hydration state within the membrane.

[0005] For example, patent application CN117476986A discloses a membrane electrode comprising an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer stacked sequentially. The anode catalyst layer comprises a first catalyst layer, a second catalyst layer, and a third catalyst layer stacked sequentially. The first catalyst layer, the second catalyst layer, and the third catalyst layer each independently include a hydrophilic catalyst. The third catalyst layer also includes a hydrophilic substance, which includes any one or a combination of at least two of TiO2, ZnO, Al2O3, ZrO2, or SiO2.

[0006] For example, patent application CN1750301A discloses a self-humidifying membrane electrode and its preparation method. The method involves pretreating a proton exchange membrane, mixing a carbon-supported platinum catalyst, a perfluorosulfonic acid polymer, a hydrophilic substance, and a low-boiling-point solvent, coating the mixture on one side of the proton exchange membrane, and drying it to obtain a hydrophilic hydrogen electrode. Then, the same mixture is applied to the other side of the proton exchange membrane and dried to obtain a hydrophobic oxygen electrode. Finally, two pieces of carbon paper are bonded to the proton exchange membrane to form a self-humidifying membrane electrode. The hydrophilic substance includes one or more of the following: perfluorosulfonic acid polymer, glycerol, succinic acid, propanesulfonic acid, amino acids, SiO2, and TiO2.

[0007] Compared to layered spraying, mixed spraying produces a more uniform structure, which is beneficial for constructing continuous proton conduction channels, electron conduction channels, and hydrophilic pores, thereby reducing interfacial impedance and improving the transport efficiency of protons and reactants. Therefore, in the traditional membrane electrode assembly (MEA) fabrication process, the catalyst, ionomer, and hydrophilic components are typically mixed into a single slurry for coating. However, this method has a significant drawback: the hydrophilic components tend to agglomerate in the slurry, leading to uneven distribution within the catalyst layer. This, in turn, affects proton conduction efficiency and water management capabilities, ultimately reducing the performance and durability of the fuel cell. Summary of the Invention

[0008] To address the aforementioned shortcomings in the prior art, this invention provides a membrane electrode for low-humidity fuel cells and its preparation method.

[0009] This invention first separately disperses the hydrophilic components and catalyst slurry, and then simultaneously atomizes and sprays them, achieving uniform dispersion of hydrophilic nanoparticles in the catalyst layer, thereby significantly improving the water management capability and electrochemical performance of the membrane electrode under high current density.

[0010] This invention first provides a method for preparing a membrane electrode for a low-humidity fuel cell, comprising the following steps: (1) Dissolve the cathode catalyst in the first solvent and add perfluorosulfonic acid resin to prepare a cathode catalyst slurry; The anode catalyst is dissolved in a second solvent, and perfluorosulfonic acid resin is added to prepare the anode catalyst slurry. Hydrophilic nanoparticles were dispersed in a third solvent to prepare a hydrophilic nanoparticle dispersion. (2) The anode catalyst slurry is coated on the anode side of the proton exchange membrane to form an anode catalyst layer; (3) The cathode catalyst slurry and hydrophilic nanoparticle dispersion are sprayed onto the cathode side of the proton exchange membrane using synchronous ultrasonic atomization to form a cathode catalyst layer, thereby obtaining CCM (Catalyst Coated Membrane).

[0011] Preferably, in step (1), the first solvent, the second solvent, and the third solvent are each selected from at least one of water and an alcohol. The alcohol is preferably isopropanol. Preferably, a mixed solution of water and isopropanol is used, with a volume ratio of water to isopropanol of 1:1 / 3 to 3, wherein the volume ratio of water to isopropanol in the first solvent is 1:1 / 3 to 3, and the volume ratio of water to isopropanol in the second solvent is 1:1 / 2 to 3. Preferably, the third solvent is isopropanol alone.

[0012] Preferably, in step (1), both the cathode catalyst and the anode catalyst are platinum-carbon catalysts, and the mass percentage of platinum in the platinum-carbon catalyst is 50%~60%.

[0013] After dissolving the cathode catalyst in the first solvent, or dissolving the anode catalyst in the second solvent, the concentration of the catalyst is 10~20 mg of catalyst per mL of solvent.

[0014] Perfluorosulfonic acid resins are readily available for purchase, typically in the form of a solution. The solvent is a mixture of water and n-propanol, with the perfluorosulfonic acid resin comprising approximately 22% by volume. For example, Chemours D2020 from Chemours, by volume percentage, contains 34% water and 44% n-propanol, with the remainder being perfluorosulfonic acid resin.

[0015] The mass ratio of the catalyst dissolved in the solvent to the perfluorosulfonic acid resin solution is 0.1~0.5:1. Preferably, in the cathode catalyst slurry, the mass ratio of the cathode catalyst dissolved in the solvent to the perfluorosulfonic acid resin solution is 0.1~0.5:1; and in the anode catalyst slurry, the mass ratio of the anode catalyst dissolved in the solvent to the perfluorosulfonic acid resin solution is 0.2~0.4:1.

[0016] Preferably, in step (1), the hydrophilic nanoparticles are at least one of SiO2, TiO2, and Al2O3; The concentration of hydrophilic nanoparticles in the hydrophilic nanoparticle dispersion is 1 mg of hydrophilic nanoparticles per 1 mL of the third solvent.

[0017] Preferably, in step (3), during synchronous ultrasonic atomization spraying, the cathode catalyst slurry and the hydrophilic nanoparticle dispersion are each transported to the spray port through independent pipelines, and the transport rate of the cathode catalyst slurry is 0.5~1.2 mL / min; the transport rate of the hydrophilic nanoparticle dispersion is 0.05~0.12 mL / min.

[0018] Preferably, in step (3), during synchronous ultrasonic atomization spraying, the ultrasonic atomization frequency is 100kHz~200kHz.

[0019] Preferably, the CCM obtained in step (3) has a Pt loading of 0.05~0.08 mg / cm³ in the anode catalyst layer. 2 The Pt loading in the cathode catalyst layer is 0.35~0.4 mg / cm³. 2 .

[0020] Preferably, after the CCM is obtained in step (3), it is encapsulated with a sealing frame material to obtain a CCM with a sealing frame; then the gas diffusion layer is attached to both sides of the CCM to obtain the membrane electrode for the low-humidity fuel cell.

[0021] The present invention also provides a low-humidity membrane electrode for fuel cells prepared by the aforementioned preparation method.

[0022] The beneficial effects of this invention are: (1) Excellent uniform distribution effect: The hydrophilic nanoparticles are mixed with the catalyst slurry in the atomized state and immediately deposited and fixed, avoiding the aggregation of hydrophilic nanoparticles in the slurry mixing and storage stage, and realizing the nanoscale uniform dispersion in the three-dimensional space of the catalyst layer.

[0023] (2) Strong controllability of components: By independently controlling the delivery rate of the two fluids, the loading and proportion of hydrophilic nanoparticles in the final catalyst layer can be precisely and flexibly controlled.

[0024] (3) Improve the performance of the catalyst layer: The uniformly dispersed hydrophilic nanoparticles construct efficient hydrophilic channels, which significantly improve the water balance management capability of the catalyst layer. Especially under low humidity or start-up conditions, it can effectively store water and reverse wet the proton exchange membrane to prevent the membrane from drying out, thereby improving the battery performance. Attached Figure Description

[0025] Figure 1 This is a diagram showing the performance of membrane electrode assembly (MEA) IV for low-humidity fuel cells.

[0026] Figure 2 This is a diagram showing the durability performance of membrane electrode assemblies (MEAs) for low-humidity fuel cells. Detailed Implementation

[0027] The perfluorosulfonic acid resin solution, purchased from Chemours, Chemours D2020, comprises 34% water and 44% n-propanol by volume percentage, with the balance being perfluorosulfonic acid resin.

[0028] The gas diffusion layer is made of Toray carbon paper.

[0029] Example 1 (1) Dissolve 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) in 50 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:2), add perfluorosulfonic acid resin solution at a mass ratio of 0.15:1 (0.15 parts of cathode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain cathode catalyst slurry after ultrasonic shearing.

[0030] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.2:1 (0.2 parts of anode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain anode catalyst slurry after ultrasonic shearing.

[0031] (3) Disperse 10 mg SiO2 in 10 mL of isopropanol to obtain SiO2 dispersion.

[0032] (4) The anode catalyst slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.05 mg / cm³). 2 ).

[0033] (5) Start the system, set the delivery rate of the cathode catalyst slurry to 0.5 mL / min, the delivery rate of the SiO2 dispersion to 0.12 mL / min, and the ultrasonic atomization frequency to 200 kHz. The two fluids are ultrasonically atomized at the nozzle and sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading of 0.35 mg / cm³). 2 ), and thus CCM is obtained.

[0034] (6) The CCM is encapsulated using a 45μm thick PEN (polyethylene naphthalate) sealing frame material.

[0035] (7) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0036] Example 2 (1) 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) was dissolved in 50 mL of a mixed solution of deionized water and isopropanol (the volume ratio of deionized water and isopropanol was 1:2). Perfluorosulfonic acid resin solution was added at a mass ratio of 0.1:1 (0.1 part of the cathode catalyst was dissolved in the mixed solution and 1 part of the perfluorosulfonic acid resin solution). After ultrasonic shearing, cathode catalyst slurry was obtained.

[0037] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.2:1 (0.2 parts of anode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain anode catalyst slurry after ultrasonic shearing.

[0038] (3) Disperse 10 mg TiO2 in 10 mL of isopropanol to obtain TiO2 dispersion.

[0039] (4) The anode catalyst slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.05 mg / cm³). 2 ).

[0040] (5) The catalyst slurry delivery rate was set to 1.2 mL / min, the TiO2 dispersion delivery rate to 0.05 mL / min, and the ultrasonic atomization frequency to 100 kHz. The two fluids were ultrasonically atomized at the nozzle and sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading of 0.35 mg / cm³). 2 ), and thus CCM is obtained.

[0041] (6) The CCM is encapsulated using a 45μm thick PEN sealing frame material.

[0042] (7) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0043] Example 3 (1) Dissolve 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) in 50 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 3:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.2:1 (0.2 parts of cathode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain cathode catalyst slurry after ultrasonic shearing.

[0044] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:3), add perfluorosulfonic acid resin solution at a mass ratio of 0.4:1 (0.4 parts of anode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain anode catalyst slurry after ultrasonic shearing.

[0045] (3) Disperse 10 mg SiO2 in 10 mL of isopropanol to obtain SiO2 dispersion.

[0046] (4) The anode catalyst slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.08 mg / cm³). 2 ).

[0047] (5) Start the system, set the delivery rate of the cathode catalyst slurry to 0.8 mL / min, the delivery rate of the SiO2 dispersion to 0.08 mL / min, and the ultrasonic atomization frequency to 150 kHz. The two fluids are ultrasonically atomized at the nozzle and sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading of 0.4 mg / cm³). 2 ), and thus CCM is obtained.

[0048] (6) The CCM is encapsulated using a 45μm thick PEN (polyethylene naphthalate) sealing frame material.

[0049] (7) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0050] Example 4 (1) Dissolve 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) in 50 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:3), add perfluorosulfonic acid resin solution at a mass ratio of 0.5:1 (0.5 parts of cathode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain cathode catalyst slurry after ultrasonic shearing.

[0051] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 2:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.3:1 (0.3 parts of anode catalyst dissolved in the mixed solution and 1 part of perfluorosulfonic acid resin solution), and obtain anode catalyst slurry after ultrasonic shearing.

[0052] (3) Disperse 10 mg SiO2 in 10 mL of isopropanol to obtain SiO2 dispersion.

[0053] (4) The anode catalyst slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.06 mg / cm³). 2 ).

[0054] (5) Start the system, set the delivery rate of the cathode catalyst slurry to 1 mL / min, the delivery rate of the SiO2 dispersion to 0.1 mL / min, and the ultrasonic atomization frequency to 200 kHz. The two fluids are ultrasonically atomized at the nozzle and sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading of 0.38 mg / cm³). 2 ), and thus CCM is obtained.

[0055] (6) The CCM is encapsulated using a 45μm thick PEN (polyethylene naphthalate) sealing frame material.

[0056] (7) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0057] Comparative Example 1 (1) 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) and 12.5 mg of SiO2 were dissolved in 50 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol was 1:2). Perfluorosulfonic acid resin solution was added at a mass ratio of 0.5:1. After ultrasonic shearing, a mixed slurry of cathode catalyst and SiO2 was obtained.

[0058] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.2:1, and obtain anode catalyst slurry after ultrasonic shearing.

[0059] (3) The anode catalyst slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.05 mg / cm³). 2 ).

[0060] (4) The delivery rate of the cathode catalyst and SiO2 mixed slurry was set to 0.5 mL / min, and the ultrasonic atomization frequency was set to 200 kHz. The mixture was sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading of 0.35 mg / cm³). 2 ), and thus CCM is obtained.

[0061] (5) The CCM is encapsulated using a 45μm thick PEN sealing frame material.

[0062] (6) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0063] Comparative Example 2 (1) 500 mg of cathode catalyst (Pt / C, containing 50% platinum by mass) was dissolved in 50 mL of a mixed solution of deionized water and isopropanol (the volume ratio of deionized water and isopropanol was 1:2), and perfluorosulfonic acid resin solution was added at a mass ratio of 0.5:1. After ultrasonic shearing, cathode catalyst slurry was obtained.

[0064] (2) Dissolve 200 mg of anode catalyst (Pt / C, containing 60% platinum by mass) in 10 mL of a mixed solution of deionized water and isopropanol (volume ratio of deionized water and isopropanol is 1:1), add perfluorosulfonic acid resin solution at a mass ratio of 0.2:1, and obtain anode catalyst slurry after ultrasonic shearing.

[0065] (3) The anode slurry is coated onto one side of the proton exchange membrane using ultrasonic spraying to form a uniform anode catalyst layer (Pt loading is 0.05 mg / cm³). 2 ).

[0066] (4) The delivery rate of the cathode catalyst and SiO2 mixed slurry was set to 0.5 mL / min, the ultrasonic atomization frequency was 200 kHz, and it was sprayed onto the other side of the proton exchange membrane to form a uniform cathode catalyst layer (Pt loading was 0.35 mg / cm³). 2 ), and thus CCM is obtained.

[0067] (5) The CCM is encapsulated using a 45μm thick PEN sealing frame material.

[0068] (6) A gas diffusion layer with a thickness of 180 μm is attached to both sides of the CCM to obtain a membrane electrode for a low-humidity fuel cell.

[0069] Detection Example 1 The membrane electrodes of the examples and comparative examples were assembled into single cells and tested under the following conditions: Single cell temperature: 80 ℃; Anode: H2 flow rate 1L / min, relative humidity 30%, back pressure 150kPa; Cathode: Air flow rate of 2L / min, relative humidity of 30%, back pressure of 150kPa.

[0070] per 100mA / cm 2 The load is applied by increasing the current density, with a dwell time of 5 minutes set for each current density, and the cutoff voltage set to >0.4V.

[0071] Table 1 From the test results ( Figure 1 , Figure 2 As shown in Table 1, under low humidity conditions of 30% RH, the test results are as follows: Figure 1 , Figure 2 As shown in Table 1, under low humidity conditions of 30% RH, the proton exchange membrane in the comparative example dehydrated, resulting in a sharp decrease in proton conductivity, a significant increase in battery internal resistance, and severe performance degradation. In contrast, the hydrophilic nanoparticles in the examples, uniformly dispersed at the nanoscale within the three-dimensional space of the catalyst layer, exhibited excellent performance under low humidity operating conditions. Specifically, the rated power density of Example 1 was 13.2% higher than that of Comparative Example 2, and after 30,000 cycle AST testing, the voltage decay rate of Example 1 was significantly lower than that of the comparative example.

Claims

1. A method for preparing a membrane electrode assembly for a low-humidity fuel cell, characterized in that, Includes the following steps: (1) Dissolve the cathode catalyst in the first solvent and add perfluorosulfonic acid resin to prepare a cathode catalyst slurry; The anode catalyst is dissolved in a second solvent, and perfluorosulfonic acid resin is added to prepare the anode catalyst slurry. Hydrophilic nanoparticles were dispersed in a third solvent to prepare a hydrophilic nanoparticle dispersion. (2) The anode catalyst slurry is coated on the anode side of the proton exchange membrane to form an anode catalyst layer; (3) The cathode catalyst slurry and hydrophilic nanoparticle dispersion are sprayed onto the cathode side of the proton exchange membrane using synchronous ultrasonic atomization to form a cathode catalyst layer, thereby obtaining CCM.

2. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, In step (1), the first solvent, the second solvent, and the third solvent are each selected from at least one of water and alcohol.

3. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 2, characterized in that, In step (1), the alcohol is isopropanol.

4. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, In step (1), both the cathode catalyst and the anode catalyst are platinum-carbon catalysts, and the mass percentage of platinum in the platinum-carbon catalyst is 50%~60%.

5. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, In step (1), the hydrophilic nanoparticles are at least one of SiO2, TiO2, and Al2O3.

6. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, In step (3), during synchronous ultrasonic atomization spraying, the cathode catalyst slurry and the hydrophilic nanoparticle dispersion are each transported to the spray port through independent pipelines. The transport rate of the cathode catalyst slurry is 0.5~1.2 mL / min, and the transport rate of the hydrophilic nanoparticle dispersion is 0.05~0.12 mL / min.

7. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, In step (3), during synchronous ultrasonic atomization spraying, the ultrasonic atomization frequency is 100kHz~200kHz.

8. The method for preparing a membrane electrode for a low-humidity fuel cell according to claim 1, characterized in that, After obtaining the CCM in step (3), it is encapsulated with a sealing frame material to obtain a CCM with a sealing frame; then the gas diffusion layer is attached to both sides of the CCM to obtain the membrane electrode for the low-humidity fuel cell.

9. A membrane electrode for a low-humidity fuel cell prepared by the preparation method according to any one of claims 1 to 8.

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