Enhanced proton exchange membrane containing multiple sulfonic acid resins and preparation method thereof

Abstract

The invention provides an enhanced proton exchange membrane containing various sulfonic acid resins. The enhanced proton exchange membrane comprises the following components: perfluorinated sulfonic acid resin: one or two of sulfonated polyetheretherketone and sulfonated polysulfone; the additive comprises polyvinyl alcohol, quaternary ammonium salt and polybenzimidazole; compared with the prior art, the enhanced proton exchange membrane provided by the invention has the following beneficial effects: the enhanced proton exchange membrane has excellent proton conductivity, mechanical properties and chemical stability, is suitable for the electrochemical fields of fuel cells, electrolyzed water and the like, and can be used in the fields of fuel cells, electrolyzed water and the like. By optimizing a resin formula and a preparation process, the performance of the membrane can be further improved, the requirements of different application scenes are met, and the invention also provides a preparation method of the enhanced proton exchange membrane containing various sulfonic acid resins.

Description

Technical Field

[0001] The invention belongs to the field of proton exchange membrane equipment, and in particular relates to an enhanced proton exchange membrane containing multiple sulfonic acid resins and a preparation method thereof. Background Art

[0002] Currently, the difficulty in synthesizing and using perfluorinated sulfonic acid resins has led to high prices for proton exchange membranes, limiting the commercialization of PEM water electrolysis technology. Some companies and laboratories have developed and pilot-tested non-fluorinated / non-perfluorinated sulfonic acid resins. While this approach offers greater convenience, lower production costs, and environmental friendliness, the chemical stability and durability of the polymer remain significant drawbacks. Furthermore, due to the technical approach, the structural and mechanical strength of these non-fluorinated proton exchange membranes is relatively weak. These issues have severely hampered the further commercialization of proton exchange membranes. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide an enhanced proton exchange membrane containing multiple sulfonic acid resins and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0004] The present invention is achieved through the following technical solution: an enhanced proton exchange membrane containing multiple sulfonic acid resins, comprising the following components:

[0005] Perfluorosulfonic acid resin: one or two of sulfonated polyetheretherketone and sulfonated polysulfone;

[0006] Additives: including polyvinyl alcohol, quaternary ammonium salt, polybenzimidazole;

[0007] Reinforcement material: one or more of polyperfluoroalkoxy, polyetheretherketone, polyphenylene sulfide, and expanded polytetrafluoroethylene.

[0008] As a preferred embodiment, the total mass ratio of sulfonated polyetheretherketone to sulfonated polysulfone in the perfluorosulfonic acid resin is no more than 2.

[0009] As a preferred embodiment, among the additives, the amount of polyvinyl alcohol added is 1%-10% of the total mass of the perfluorosulfonic acid resin, the amount of quaternary ammonium salt added is 0.1%-5% of the total mass of the perfluorosulfonic acid resin, and the amount of polybenzimidazole added is 0.5%-15% of the total mass of the perfluorosulfonic acid resin.

[0010] As a preferred embodiment, the mass of the reinforcing material accounts for 5%-50% of the total mass of the proton exchange membrane.

[0011] A method for preparing an enhanced proton exchange membrane containing multiple sulfonic acid resins comprises the following steps:

[0012] Perfluorosulfonic acid resin, polyvinyl alcohol, quaternary ammonium salt and polybenzimidazole are mixed and treated by a homogenization method to obtain a uniform slurry;

[0013] The slurry is coated on the reinforcing material by a coating method, and the enhanced proton exchange membrane is obtained after drying.

[0014] As a preferred embodiment, the homogenization method is high-speed shearing, ball milling or high-pressure homogenization;

[0015] The coating method is slit coating, blade coating or micro-concave coating.

[0016] As a preferred embodiment, the drying temperature is 50° C.-150° C., and the drying time is 1 hour-24 hours.

[0017] As a preferred embodiment, when the reinforcing material is expanded polytetrafluoroethylene (ePTFE), its porosity is 60%-95% and its thickness is 10 μm-100 μm.

[0018] Enhanced proton exchange membranes are used in fuel cells or water electrolysis.

[0019] After adopting the above technical solution, the beneficial effects of the present invention are: through chemical / physical cross-linking and mixing of multiple sulfonic acid resins, the cost of the proton membrane is further reduced, and at the same time, through the introduction of non-fluorine resin, the internal structure of the membrane is optimized, and the proton conductivity and hydrogen barrier effect of the membrane are further improved.

[0020] The enhanced proton exchange membrane of this invention has excellent proton conductivity, mechanical properties, and chemical stability, making it suitable for electrochemical applications such as fuel cells and water electrolysis. By optimizing the resin formulation and preparation process, the membrane's performance can be further improved to meet the needs of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 Schematic diagram of the enhanced proton exchange membrane of Example 1.

[0023] Figure 2 Graph showing the hydrogen content in oxygen for Example 1, Example 2, Example 3, and the control group. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] The present invention provides a technical solution: an enhanced proton exchange membrane containing multiple sulfonic acid resins, comprising the following components:

[0026] Perfluorosulfonic acid resin: one or two of sulfonated polyetheretherketone and sulfonated polysulfone;

[0027] Additives: including polyvinyl alcohol, quaternary ammonium salt, polybenzimidazole;

[0028] Reinforcement material: one or more of polyperfluoroalkoxy, polyetheretherketone, polyphenylene sulfide, and expanded polytetrafluoroethylene.

[0029] The total mass ratio of sulfonated polyetheretherketone and sulfonated polysulfone in the perfluorosulfonic acid resin is no more than 2.

[0030] Among the additives, the amount of polyvinyl alcohol added is 1%-10% of the total mass of the perfluorosulfonic acid resin, the amount of quaternary ammonium salt added is 0.1%-5% of the total mass of the perfluorosulfonic acid resin, and the amount of polybenzimidazole added is 0.5%-15% of the total mass of the perfluorosulfonic acid resin.

[0031] The mass of the reinforcing material accounts for 5%-50% of the total mass of the proton exchange membrane.

[0032] The present invention provides a technical solution: a method for preparing an enhanced proton exchange membrane containing multiple sulfonic acid resins, comprising the following steps:

[0033] Perfluorosulfonic acid resin, polyvinyl alcohol, quaternary ammonium salt and polybenzimidazole are mixed and treated by a homogenization method to obtain a uniform slurry;

[0034] The slurry is coated on the reinforcing material by a coating method, and the enhanced proton exchange membrane is obtained after drying.

[0035] The homogenization method is high-speed shearing, ball milling or high-pressure homogenization;

[0036] The coating method is slit coating, blade coating or micro-concave coating.

[0037] The drying temperature is 50° C.-150° C., and the drying time is 1 hour-24 hours.

[0038] When the reinforcing material is expanded polytetrafluoroethylene (ePTFE), its porosity is 60%-95% and its thickness is 10 μm-100 μm.

[0039] The present invention provides a technical solution: an enhanced proton exchange membrane is applied in a fuel cell or in water electrolysis.

[0040] As an embodiment of the present invention:

[0041] Example 1:

[0042] A combination of perfluorosulfonic acid resin and sulfonated polyetheretherketone (sPEEK), using expanded polytetrafluoroethylene (ePTFE) as reinforcement

[0043] Step 1. Mixing and Homogenization: Add 50g of perfluorosulfonic acid resin, 30g of sulfonated polyetheretherketone (sPEEK), 5g of polyvinyl alcohol (PVA), 20g of purified water, 40g of ethanol, and 10g of n-propanol to a reactor. Use a high-speed shear homogenizer at 10,000 rpm for 30 minutes to ensure thorough mixing of the components and form a uniform slurry.

[0044] Step 2. Coating: Place the expanded polytetrafluoroethylene (ePTFE) film on the substrate holder of the coating machine. Use the slot coating method to evenly coat the slurry on the surface of the ePTFE film, controlling the coating wet thickness to 100 μm.

[0045] Step 3. Drying: Place the coated film in an oven, set the maximum temperature to 180°C, and the overall drying time to 1 hour to ensure that the slurry is completely dry and forms a uniform film layer.

[0046] Performance test results: The performance of the membrane produced by this method is as follows:

[0047] Proton conductivity: 0.12S / cm (at 80°C, 100% relative humidity)

[0048] Tensile strength: 50MPa

[0049] Elongation at break: 120%

[0050] Chemical stability: After being immersed in sulfuric acid solution at 80°C for 100 hours, the performance has no obvious decline;

[0051] Example 2:

[0052] Step 1. Mixing and Homogenization: Add 60g of perfluorosulfonic acid resin, 10g of sulfonated polysulfone (sPSU), 3g of polyvinyl alcohol (PVA), 1g of quaternary ammonium salt, 1g of polybenzimidazole (PBI), 10g of n-propanol, 30g of dimethyl sulfone, 2g of purified water, and 30g of isopropanol to a reaction vessel. Homogenize using a ball mill for 4 hours at 200 rpm to ensure thorough mixing of the components to form a uniform slurry.

[0053] Step 2. Coating: Use a doctor blade coating method to evenly coat the slurry on the surface of the release film, controlling the coating thickness to 200 μm, and place the pretreated polyetheretherketone (PEEK) mesh on the wet film.

[0054] Step 3. Drying: Place the coated film in an oven, set the temperature to 180°C, and dry it for 1 hour to ensure that the slurry is completely dry and forms a uniform film layer.

[0055] Performance test results

[0056] Proton conductivity: 0.10S / cm (at 80°C, 100% relative humidity)

[0057] Tensile strength: 45MPa

[0058] Elongation at break: 30%

[0059] Chemical stability: After being immersed in sulfuric acid solution at 80℃ for 100 hours, the performance has no obvious decline.

[0060] Example 3: Perfluorosulfonic acid resin alone, using polyperfluoroalkoxy (PFA) as a reinforcing material Raw material ratio Perfluorosulfonic acid resin: 70g Polyvinyl alcohol (PVA): 4g Quaternary ammonium salt: 1.5g Polybenzimidazole (PBI): 2.5g Polyperfluoroalkoxy (PFA): 90g (thickness 60μm)

[0061] Step 1. Mixing and Homogenization: Add 70g of perfluorosulfonic acid resin, 4g of polyvinyl alcohol (PVA), 1.5g of quaternary ammonium salt, 2.5g of polybenzimidazole (PBI), 10g of NMP, and 100g of DMAc to a reaction kettle. Use a high-pressure homogenizer to homogenize at 1200 bar for 30 minutes to ensure thorough mixing of the components to form a uniform slurry.

[0062] Step 2. Coating: Use a doctor blade coating method to evenly coat the slurry on the surface of the release film, controlling the coating thickness to 330 μm.

[0063] Step 3. Drying: Place the coated film in an oven with a set temperature of 210°C and a drying time of 30 hours to ensure that the slurry is completely dry and forms a uniform film layer.

[0064] Performance test results

[0065] Proton conductivity: 0.08S / cm (at 80°C, 100% relative humidity)

[0066] Tensile strength: 40MPa

[0067] Elongation at break: 200%

[0068] Chemical stability: After being immersed in sulfuric acid solution at 80℃ for 100 hours, the performance has no obvious decline.

[0069] Reference Figure 2 As shown in Table 1, the control group is a proton exchange membrane in the prior art. It can be seen that the present invention achieves further cost reduction of the proton membrane through chemical / physical crosslinking and mixing of multiple sulfonic acid resins. At the same time, by introducing non-fluorine resin, the internal structure of the membrane is optimized, and the proton conductivity and hydrogen barrier effect of the membrane are further improved.

[0070] Hydrogen value in oxygen (%) 0MPa-2A / cm2 2MPa-0.5A / cm2 2MPa-2A / cm2 Example 1 0.25 0.95 0.53 Example 2 0.01 0.78 0.05 Example 3 0.05 0.58 0.01 control group 0.15 1.72 0.72

[0071] Table 1

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An enhanced proton exchange membrane containing multiple sulfonic acid resins, characterized in that: Includes the following ingredients: Perfluorosulfonic acid resin: one or two of sulfonated polyetheretherketone and sulfonated polysulfone; Additives: including polyvinyl alcohol, quaternary ammonium salt, polybenzimidazole; Reinforcement material: one or more of polyperfluoroalkoxy, polyetheretherketone, polyphenylene sulfide, and expanded polytetrafluoroethylene.

2. The enhanced proton exchange membrane containing multiple sulfonic acid resins and the preparation method thereof according to claim 1, characterized in that: The total mass ratio of sulfonated polyetheretherketone and sulfonated polysulfone in the perfluorosulfonic acid resin is no more than 2.

3. The enhanced proton exchange membrane containing multiple sulfonic acid resins and the preparation method thereof according to claim 2, characterized in that: Among the additives, the amount of polyvinyl alcohol added is 1%-10% of the total mass of the perfluorosulfonic acid resin, the amount of quaternary ammonium salt added is 0.1%-5% of the total mass of the perfluorosulfonic acid resin, and the amount of polybenzimidazole added is 0.5%-15% of the total mass of the perfluorosulfonic acid resin.

4. The enhanced proton exchange membrane containing multiple sulfonic acid resins and the preparation method thereof according to claim 3, characterized in that: The mass of the reinforcing material accounts for 5%-50% of the total mass of the proton exchange membrane.

5. A method for preparing a reinforced proton exchange membrane containing multiple sulfonic acid resins according to any one of claims 1 to 4, characterized in that: The following steps are involved: Perfluorosulfonic acid resin, polyvinyl alcohol, quaternary ammonium salt and polybenzimidazole are mixed and treated by a homogenization method to obtain a uniform slurry; The slurry is coated on the reinforcing material by a coating method, and the enhanced proton exchange membrane is obtained after drying.

6. The method for preparing a reinforced proton exchange membrane containing multiple sulfonic acid resins according to claim 5, characterized in that: The homogenization method is high-speed shearing, ball milling or high-pressure homogenization; The coating method is slit coating, blade coating or micro-concave coating.

7. The method for preparing a reinforced proton exchange membrane containing multiple sulfonic acid resins according to claim 5, wherein: The reinforcing material is pretreated before use, and the pretreatment method includes surface activation, chemical modification or physical treatment.

8. The method for preparing a reinforced proton exchange membrane containing multiple sulfonic acid resins according to claim 5, wherein: The drying temperature is 50° C.-150° C., and the drying time is 1 hour-24 hours.

9. The method for preparing a reinforced proton exchange membrane containing multiple sulfonic acid resins according to claim 5, wherein: When the reinforcing material is expanded polytetrafluoroethylene (ePTFE), its porosity is 60%-95% and its thickness is 10 μm-100 μm.

10. The enhanced proton exchange membrane containing multiple sulfonic acid resins according to claim 4 or 9, characterized in that: Enhanced proton exchange membranes are used in fuel cells or water electrolysis.

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