Composite enhanced anion exchange membrane and preparation method thereof

Abstract

The invention belongs to the technical field of anion exchange membranes, and particularly provides a novel composite enhanced anion exchange membrane and a preparation method thereof. The preparation method provided by the invention comprises the following steps: S100, coating a substrate with a film casting solution, and heating until an initial functional film layer with the solid content of more than or equal to 50% is formed; and S200, placing a supporting net on the initial functional membrane layer, pressing the supporting net, and heating and curing to obtain the composite anion exchange membrane. According to the invention, the supporting net is pressed into the uncured functional membrane layer with certain viscosity, so that the membrane casting liquid is in full contact with the supporting net, and mechanical interlocking is realized, thereby effectively improving the connection force between the supporting net and the functional membrane layer, and solving the problem that the supporting net and the functional membrane layer are easy to separate and fall off due to stress.

Description

Technical Field

[0001] This invention relates to the field of anion exchange membrane technology, and more specifically, to a composite-enhanced anion exchange membrane and its preparation method. Background Technology

[0002] Against the backdrop of today's energy transition, hydrogen energy, as a clean and efficient energy carrier, is gradually becoming a focus of global attention in the energy sector. Anion exchange membranes, as key materials in the development and utilization of hydrogen energy, directly affect the efficiency and stability of the entire energy system. Existing enhanced anion exchange membranes mostly adopt a double-layer structure, consisting of a support mesh and a functional membrane layer covering the support mesh. This structural design meets the basic performance requirements of the membrane to a certain extent, but with the continuous expansion of application scenarios and the increasing demands on membrane performance, its inherent shortcomings are gradually becoming apparent.

[0003] In terms of mechanical properties, since the support mesh and functional membrane layer are layered structures, the bonding force between them mainly relies on physical adsorption or simple adhesion. When the anion exchange membrane is subjected to external forces such as stretching, bending, or impact during assembly into the electrolyzer equipment, stress concentration is prone to occur at the interface between the support mesh and the functional membrane layer. Once the stress exceeds the bonding strength at the interface, it will cause the support mesh and functional membrane layer to separate, resulting in a significant decrease in the overall mechanical properties of the membrane and severely affecting its service life. Moreover, when the anion exchange membrane is used in water electrolysis hydrogen production equipment, it is immersed in alkaline solution for a long time. The difference in swelling rate between the support mesh and the functional membrane layer leads to huge internal stress at the interface between the functional membrane layer and the support mesh. Under long-term action, the bonding force at the interface will gradually weaken, and separation of the support mesh and functional membrane layer may also occur. Delamination of the support mesh and functional membrane layer under stress will result in a higher hydrogen content in the oxygen produced during water electrolysis hydrogen production.

[0004] Furthermore, the fabrication process of layered structures is relatively complex, requiring separate treatment of the support network and functional membrane layers, which increases fabrication costs and process difficulty. Moreover, due to compatibility issues between the layers, defects are prone to occur during fabrication, affecting the consistency of membrane quality and performance. In summary, existing enhanced anion exchange membranes have many shortcomings in terms of mechanical properties, ion conductivity, and fabrication processes, urgently requiring a new technological solution to address these issues and meet the demands of the modern energy sector for high-performance anion exchange membranes. Summary of the Invention

[0005] This invention presses a support mesh into a functional membrane layer with a certain viscosity and uncured state, allowing the casting liquid to fully contact the support mesh and achieve mechanical interlocking. This effectively improves the connection between the support mesh and the functional membrane layer, solving the problem of easy separation and detachment of the support mesh and the functional membrane layer under stress.

[0006] To address the above problems, this invention provides a novel method for preparing a composite-enhanced anion exchange membrane, comprising: S100: The casting solution is coated onto the substrate and heated until an initial functional film layer with a solid content of 50wt% or more is formed. S200: Place the support mesh on the initial functional membrane layer, press the support mesh, and heat to cure to obtain a composite anion exchange membrane.

[0007] It should be noted that the solid content mentioned in this invention refers to the percentage by mass of the remaining portion after the casting solution has dried relative to the total mass of the casting solution before drying.

[0008] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 800 mPa•s and 12000 mPa•s.

[0009] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 1000 mPa•s and 10000 mPa•s.

[0010] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 2000 mPa•s and 8000 mPa•s.

[0011] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 4000 mPa•s and 6000 mPa•s.

[0012] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 3000 mPa•s and 7000 mPa•s.

[0013] In one embodiment of the present invention, in S100, the viscosity of the casting solution is between 4500 mPa•s and 5500 mPa•s.

[0014] In one embodiment of the present invention, in S100, the viscosity of the casting solution is 5000 mPa•s.

[0015] In one embodiment of the present invention, in S100, the heating temperature is controlled between 30°C and 130°C, and the heating time is controlled between 20 min and 200 min.

[0016] In one embodiment of the present invention, in S100, the heating temperature is controlled between 40°C and 120°C, and the heating time is controlled between 30 min and 120 min.

[0017] In one embodiment of the present invention, in S100, the heating temperature is controlled between 60°C and 130°C, and the heating time is controlled between 60 min and 180 min.

[0018] In one embodiment of the present invention, in S100, the heating temperature is controlled at 80°C-125°C and the heating time is controlled at 80 min-140 min.

[0019] In one embodiment of the present invention, in S100, the heating temperature is controlled at 100℃-125℃ and the heating time is controlled at 100min-130min.

[0020] In one embodiment of the present invention, in S100, the heating temperature is controlled at 70°C-110°C and the heating time is controlled at 40 min-80 min.

[0021] In one embodiment of the present invention, in S100, the heating temperature is controlled at 95°C-105°C and the heating time is controlled at 50 min-70 min.

[0022] In one embodiment of the present invention, in S200, the thickness of the support mesh is 20μm-120μm, and the support mesh is at least one of polyphenylene sulfide support mesh, polyether ether ketone support mesh, polyethylene support mesh, and nonwoven fabric.

[0023] In one embodiment of the present invention, in S200, the thickness of the support mesh is 30μm-50μm, and the material of the support mesh is polyetheretherketone support mesh.

[0024] In one embodiment of the present invention, in S200, the thickness of the support mesh is 50μm-70μm, and the material of the support mesh is polyethylene support mesh.

[0025] In one embodiment of the present invention, in S200, the thickness of the support mesh is 35μm-45μm, and the material of the support mesh is polyetheretherketone support mesh.

[0026] In one embodiment of the present invention, in S200, the thickness of the support mesh is 50μm-60μm, and the material of the support mesh is polyphenylene sulfide support mesh.

[0027] In one embodiment of the present invention, in S200, the temperature for heating and curing is controlled to be between 35°C and 90°C, and the heating time is between 25 min and 70 min.

[0028] In one embodiment of the present invention, in S200, the temperature for heating and curing is controlled to be between 40°C and 80°C, and the heating time is between 30 min and 60 min.

[0029] In one embodiment of the present invention, in S200, the temperature for heating and curing is controlled to be between 60°C and 75°C, and the heating time is between 45 min and 55 min.

[0030] In one embodiment of the present invention, in S200, the temperature for heating and curing is controlled to be between 45°C and 55°C, and the heating time is between 35 min and 45 min.

[0031] In one embodiment of the present invention, in S200, a support mesh is placed on the initial functional membrane layer, and then the support mesh is pressed until the support mesh is fully embedded in the initial functional membrane layer.

[0032] In one embodiment of the present invention, S200 specifically includes: S210: Place the support mesh on the initial functional membrane layer, press the support mesh so that at least part of the support mesh is embedded in the initial functional membrane layer, heat it, and obtain the composite substrate; S220: The casting solution is coated again on one side of the support mesh of the composite substrate and heated to cure, thus obtaining the composite anion exchange membrane.

[0033] In one embodiment of the present invention, in S220, the temperature for heating and curing is controlled to be between 60°C and 120°C, and the heating time is between 60 min and 120 min.

[0034] In one embodiment of the present invention, in S100, the solid content of the initial functional film layer is controlled to be between 60wt% and 80wt%.

[0035] The present invention also provides a novel composite enhanced anion exchange membrane, which is prepared by the above preparation method.

[0036] Compared with the prior art, the advantages of the present invention are: (1) In the preparation method of the present invention, by controlling the four indicators of the casting liquid viscosity, the pre-curing temperature and time, and the solid content, an initial functional film layer with a certain viscosity can be prepared. The viscosity of the initial functional film layer is the key to the embedding of the support mesh. (2) In the preparation method of the present invention, the most important step is to embed the porous support mesh into the initial functional membrane layer with a certain viscosity by a certain pressure. This step not only allows the casting liquid to completely fill the gaps in the support mesh, but also allows the casting liquid to fully contact the support mesh and expel the air between them, so that the connection performance between the support mesh and the functional membrane layer is much higher than that of ordinary physical adsorption or bonding. (3) The present invention also provides a method for preparing a secondary coating casting liquid. By coating the casting liquid again on one side of the support mesh, the integrity of the functional film layer can be improved, and the effect of the support mesh and the functional film layer being integrated can be better guaranteed. (4) The composite anion exchange membrane prepared by the present invention is not a conventional layered structure. The present invention can achieve the effect of the support network being completely wrapped by the casting liquid through the process of embedding the support network. The two are tightly bonded by mechanical interlocking and the interface formed by van der Waals forces, which can effectively improve the connection between the support network and the functional membrane layer. (5) In the preparation method of the present invention, the functional film layer is cured by a secondary curing method, which can further enhance the connection between the support network and the functional film layer. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the initial functional film layer prepared in Embodiments 1 and 2 of the present invention; Figure 2 This is a schematic diagram of the structure of the composite substrate prepared in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the composite anion exchange membranes prepared in Examples 1 and 2 of the present invention.

[0038] Terminology Explanation In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] The terms “room temperature” or “normal temperature” refer to ambient temperature, which is approximately 10°C to approximately 35°C, approximately 10°C to approximately 30°C, or approximately 20°C to 30°C, or approximately 25°C.

[0040] The term "wt%" indicates a weight percentage.

[0041] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] In the following content, all figures disclosed herein, whether or not they use the words "approximately" or "about," are approximate values. The value of each figure may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15%, or 20%. Whenever a figure with a value of N is disclosed, any figure with a value of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15%, or N+ / -20% will be explicitly disclosed, where "+ / -" indicates addition or subtraction. Detailed Implementation

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0044] This invention provides a novel method for preparing a composite-enhanced anion exchange membrane, comprising: S100: The casting solution is applied to the substrate and heated until an initial functional film layer with a solid content of ≥50% is formed; S200: Place the support mesh on the initial functional membrane layer, press the support mesh, and heat to cure to obtain a composite anion exchange membrane.

[0045] In this process, the casting solution is coated onto the substrate using an anion exchange membrane coating machine. The viscosity of the casting solution is a key factor affecting whether the initial functional membrane layer can be effectively connected to the support network. Typically, the viscosity of the casting solution is controlled between 800 mPa•s and 12000 mPa•s.

[0046] The preparation method of the casting solution in this application is as follows: 10g of polymer is added to 60ml of solvent, and the mixture is continuously stirred at 40℃-80℃ until the polymer is completely dissolved, obtaining a casting solution with uniform and stable composition. The polymer is prepared using the method provided in Chinese Patent CN114989437B.

[0047] In S200, the thickness of the support mesh is between 20μm and 120μm, and the support mesh is at least one of polyphenylene sulfide support mesh, polyether ether ketone support mesh, polyethylene support mesh, and nonwoven fabric.

[0048] This application mainly provides two methods for preparing composite anion exchange membranes of different types.

[0049] The first preparation method is as follows: S100: The casting solution is applied to the substrate and heated until an initial functional film layer with a solid content of ≥50% is formed; S200: Place the support mesh on the initial functional membrane layer, then press the support mesh until it is fully embedded in the initial functional membrane layer, heat and cure to obtain a composite anion exchange membrane.

[0050] To improve the connection between the initial functional film layer and the support network, in S100, the coating speed of the casting solution is controlled at 0.5 m / min-1.5 m / min, the coating thickness at 50 μm-120 μm, and the viscosity at 1000 mPa•s-10000 mPa•s. In the subsequent heating step, the heating temperature is controlled at 60℃-130℃ and the heating time at 60 min-180 min. Finally, the solid content of the formed initial functional film layer is controlled at 60%-80%.

[0051] Preferably, in S100, the coating speed of the casting solution is controlled at 0.7 m / min-1.2 m / min, the coating thickness at 85 μm-110 μm, and the viscosity at 2000 mPa•s-8000 mPa•s. The heating temperature in the subsequent heating step is controlled at 80℃-125℃, and the heating time at 80 min-140 min. Finally, the solid content of the initial functional film layer is controlled at 60%-70%.

[0052] More preferably, in S100, the coating speed of the casting solution is controlled at 0.9 m / min-1.1 m / min, the coating thickness at 90 μm-105 μm, and the viscosity at 4000 mPa•s-6000 mPa•s. The heating temperature in the subsequent heating step is controlled at 100℃-125℃, and the heating time is controlled at 100 min-130 min. Finally, the solid content of the initial functional film layer is controlled at 63%-68%.

[0053] Since the support mesh is embedded into the initial functional membrane layer by pressing in the design of this invention, certain requirements are placed on the thickness, material, and pressing pressure of the support mesh to ensure complete encapsulation and contact with the initial functional membrane layer. In S200, the thickness of the support mesh is controlled to be 20μm-80μm, the pressing pressure is controlled to be 0.1MPa-1.2MPa, the material of the support mesh is one of polyphenylene sulfide support mesh, polyether ether ketone support mesh, polyethylene support mesh, and nonwoven fabric, and the heating and curing temperature is controlled to be 40℃-80℃, and the heating time is controlled to be 30min-60min.

[0054] Preferably, in S200, the thickness of the support mesh is controlled to be 30μm-50μm, the pressing pressure is controlled to be 0.3MPa-0.6MPa, the material of the support mesh is polyetheretherketone support mesh, and the heating curing temperature is controlled to be 60℃-75℃, and the heating time is controlled to be 45min-55min.

[0055] Preferably, in S200, the thickness of the support mesh is controlled to be 50μm-70μm, the pressing pressure is controlled to be 0.7MPa-0.9MPa, the material of the support mesh is polyethylene support mesh, and the heating curing temperature is controlled to be 45℃-55℃, and the heating time is controlled to be 35min-45min.

[0056] Preferably, in S200, the support net is pressed by a roller pressing device, and the pressing pressure is controlled at 0.35MPa-0.45MPa and the roller pressing speed is controlled at 0.7m / min-0.9m / min.

[0057] By comparing the heating temperature and time in S100 and the curing heating temperature and time in S200, it can be found that the two-stage heating method used in this application to cure the functional film layer not only facilitates the formation of chemical connection between the support mesh and the functional film layer during the second heating process, but also allows the support mesh to be completely wrapped by the casting liquid through gradient heating, and its voids are completely filled.

[0058] In this application, the second preparation method is as follows: S100: The casting solution is applied to the substrate and heated until an initial functional film layer with a solid content of ≥50% is formed; S210: Place the support mesh on the initial functional membrane layer, press the support mesh so that at least part of the support mesh is embedded in the initial functional membrane layer, heat it, and obtain the composite substrate; S220: The casting solution is coated again on one side of the support mesh of the composite substrate and heated to cure, thus obtaining the composite anion exchange membrane.

[0059] To improve the connection between the initial functional film layer and the support network, in S100, the coating speed of the casting solution is controlled at 0.5 m / min-1.5 m / min, the coating thickness at 15 μm-45 μm, and the viscosity at 1000 mPa•s-10000 mPa•s. The heating temperature in the subsequent heating step is controlled at 40℃-120℃, and the heating time at 30 min-120 min. Finally, the solid content of the formed initial functional film layer is controlled at 60%-80%.

[0060] Preferably, in S100, the coating speed of the casting solution is controlled at 0.8 m / min-1.4 m / min, the coating thickness at 20 μm-40 μm, and the viscosity at 3000 mPa•s-7000 mPa•s. The heating temperature in the subsequent heating step is controlled at 70℃-110℃, and the heating time is controlled at 40 min-80 min. Finally, the solid content of the initial functional film layer is controlled at 70%-80%.

[0061] More preferably, in S100, the coating speed of the casting solution is controlled at 0.95 m / min-1.15 m / min, the coating thickness is controlled at 25 μm-35 μm, and the viscosity is controlled at 4500 mPa•s-5500 mPa•s. In the subsequent heating step, the heating temperature is controlled at 95℃-105℃ and the heating time is controlled at 50 min-70 min. Finally, the solid content of the initial functional film layer is controlled at 71%-75%.

[0062] In S210, the thickness of the support mesh is controlled to be between 20μm and 80μm, the pressing pressure is between 0.1MPa and 1.2MPa, the material of the support mesh is one of polyphenylene sulfide support mesh, polyether ether ketone support mesh, polyethylene support mesh, and non-woven fabric, and the heating temperature is controlled to be between 40℃ and 80℃, and the heating time is between 30min and 60min.

[0063] Preferably, in S210, the thickness of the support mesh is controlled to be 35μm-45μm, the pressing pressure is controlled to be 0.2MPa-0.4MPa, the material of the support mesh is polyetheretherketone support mesh, and the heating temperature is controlled to be 55℃-65℃, and the heating time is controlled to be 35min-45min.

[0064] Preferably, in S210, the thickness of the support mesh is controlled to be 50μm-60μm, the pressing pressure is controlled to be 0.5MPa-0.6MPa, the material of the support mesh is polyphenylene sulfide support mesh, and the heating temperature is controlled to be 65℃-75℃, and the heating time is controlled to be 45min-55min.

[0065] Preferably, in S210, the support net is pressed by a flat plate pressing device, and the pressing pressure is controlled to be between 0.25 MPa and 0.35 MPa, and the pressing time is between 8 s and 12 s.

[0066] In S220, the coating speed of the casting liquid is controlled at 0.5m / min-1.5m / min, the coating thickness at 15μm-45μm, and the viscosity at 1000mPa•s-10000mPa•s. The heating temperature in the subsequent heating and curing step is controlled at 60℃-120℃, and the heating time is controlled at 60min-120min.

[0067] Preferably, in S220, the coating speed of the casting liquid is controlled to be 0.8 m / min-1.1 m / min, the coating thickness is controlled to be 20 μm-40 μm, and the viscosity is controlled to be 4000 mPa•s-7000 mPa•s. The heating temperature in the subsequent heating and curing step is controlled to be 90℃-105℃ and the heating time is controlled to be 85 min-100 min.

[0068] Example 1: This embodiment provides a novel method for preparing a composite-enhanced anion exchange membrane, comprising: S100: Fix the PET base layer on the unwinding device of the coating machine, set the coating speed to 1m / min and the wet film thickness to 30μm, start the coating machine to uniformly apply the casting solution with a viscosity of 5000mPa•s to the surface of the PET release film; after coating, transfer the base layer with the casting solution to the oven, set the oven temperature to 100℃, heat for 60min, take out the sample after heating, and measure the solid content of the functional film layer by the solid content analyzer. The solid content of the functional film layer is 72%, forming an initial functional film layer with viscosity; S210: A 40 μm thick polyetheretherketone (PEEK) support mesh is laid flat on the surface of the initial functional film layer. The support mesh is pressed using a flat plate press (pressure set to 0.3 MPa) for 10 seconds. Due to the adhesiveness of the initial functional film layer, the PEEK support mesh is completely embedded in the film layer. Observation under an optical microscope shows that the pores of the support mesh are fully filled with the casting liquid, with no voids remaining. The functional film layer with the embedded PEEK support mesh is then placed back into an oven at 60°C for 40 minutes. During the heating process, the casting liquid further crosslinks and solidifies, and the support mesh and the initial functional film layer form a strong bond, resulting in a composite substrate. S220: Fix the composite substrate with the support mesh facing upward on the coating machine, set the coating speed to 1m / min and the wet film thickness to 30μm, coat with a casting solution of the same viscosity of 5000mPa•s, transfer to an oven after coating, set the temperature to 100℃ and the heating time to 90min; after heating, allow it to cool naturally to room temperature to obtain the composite anion exchange membrane.

[0069] Observation revealed that the membrane has no layered structure, and the support mesh and functional membrane layer are fused together by the casting solution to form a single unit.

[0070] Example 2: S100: Fix the PET substrate on the coating machine, adjust the coating speed to 1m / min and the wet film thickness to 100μm, apply the casting solution with a viscosity of 5000mPa•s to the surface of the PET film, and then send the sample into the oven. Set the oven temperature to 120℃ and the heating time to 120min. After heating, the solid content of the functional film layer is 65%, forming an initial functional film layer with good adhesion. There are no defects such as bubbles or cracks on the film layer surface. S200: A 40 μm thick polyetheretherketone (PEEK) support mesh is aligned with the surface of the initial functional membrane layer. A roller press (rolling speed 0.8 m / min, pressure 0.4 MPa) is used to embed the support mesh into the initial functional membrane layer. Due to the suitable viscosity of the initial functional membrane layer, the PEEK support mesh completely adheres to the membrane layer, and its pores are fully filled by the casting adhesive. The functional membrane layer with the embedded PEEK support mesh is placed in an oven, and the oven temperature is set to 70℃ for 50 minutes. During the drying process, the membrane layer is observed periodically to avoid excessive shrinkage. After drying, the support mesh and the initial functional membrane layer are tightly bonded, thus preparing a composite anion exchange membrane.

[0071] Observation revealed that the membrane has no layered structure, and the support mesh and functional membrane layer are fused together by the casting solution to form a single unit.

[0072] The performance of the composite anion exchange membranes prepared in Examples 1 and 2 was tested, and the test results are shown in Table 1. The comparative example is a commercially available composite reinforced anion exchange membrane with a polyether ether ketone (PEEK) support network.

[0073] Table 1: Performance test results of composite anion exchange membranes

[0074] Existing interlayer reinforced membranes only physically adhere to the support mesh, resulting in weak interfacial forces. During assembly, operations such as cutting and stretching can easily lead to interlayer delamination and membrane rupture, resulting in high rework rates and potentially causing electrolyte leakage and electrode short circuits.

[0075] As shown in Table 1, the tensile strength of existing membrane products is 50 MPa, while the tensile strength of Examples 1 and 2 can reach 61 MPa to 62 MPa. This invention employs an integrated structure with mechanical interlocking, allowing the support mesh to be completely embedded in the initial membrane layer. The casting solution fills the pores to form a continuous whole, enhancing interfacial adhesion. The swelling rate of existing membrane products is 3.15%, while the swelling rate of the membrane prepared by this invention, when immersed in alkaline solution, is significantly reduced to 1.89%.

[0076] In actual assembly, the breakage rate of the integrated membrane of the present invention was reduced from 15% to below 2%, proving that the integrated membrane can withstand greater tension, is less prone to cracking during cutting, and adheres more evenly to the electrode. Moreover, since no additional protective layer is required, the assembly time of a single device is reduced by 20%. At the same time, due to the improved stability of the membrane material, no additional protective layer or reinforcement process is required, and the assembly time of a single water electrolysis hydrogen production device is reduced by about 20%, which greatly improves the assembly efficiency in large-scale production and lays the foundation for the rapid implementation of water electrolysis hydrogen production technology.

[0077] In the process of producing hydrogen through water electrolysis, hydrogen is produced at the cathode and oxygen at the anode. If the gas separation performance of the anion exchange membrane is insufficient, hydrogen can easily diffuse through the membrane to the anode, leading to an increase in the hydrogen content in the oxygen. When the hydrogen content in the oxygen exceeds a certain amount, it reaches the lower explosive limit of hydrogen, posing a serious safety risk. Therefore, controlling the hydrogen content in the oxygen is one of the reasons restricting the development of anion exchange membrane water electrolysis hydrogen production technology. The integrated structure relies on mechanical interlocking to form a gapless, dense structure, requiring gas to pass through the micropores of the membrane, resulting in a longer path and increased resistance.

[0078] In actual testing of the water electrolysis hydrogen production electrolyzer (operating conditions: temperature 60℃, current density 1A / cm²), 2 The electrolytic cell using an integrated membrane structure maintains a stable hydrogen content in oxygen between 0.2% and 0.25%, compared to 0.4% to 0.5% in existing membrane products.

[0079] The results above show that the composite anion exchange membrane prepared in this application can significantly improve the swelling resistance and structural stability of the membrane material and extend its service life.

[0080] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing a composite-enhanced anion exchange membrane, characterized in that, include: S100: The casting solution is coated onto the substrate and heated until an initial functional film layer with a solid content of more than 50 wt% is formed. S200: Place the support mesh on the initial functional membrane layer, press the support mesh, and heat to cure to obtain a composite anion exchange membrane.

2. The preparation method according to claim 1, characterized in that, In S100, the viscosity of the casting solution is between 800 mPa•s and 12000 mPa•s.

3. The preparation method according to claim 1, characterized in that, In S100, the heating temperature is controlled between 30℃ and 130℃, and the heating time is controlled between 20min and 200min.

4. The preparation method according to claim 1, characterized in that, In S200, the thickness of the support mesh is between 20μm and 120μm, and the support mesh is at least one of polyphenylene sulfide support mesh, polyether ether ketone support mesh, polyethylene support mesh, and nonwoven fabric.

5. The preparation method according to claim 1, characterized in that, In step S200, the temperature for heating and curing is controlled to be between 35°C and 90°C, and the heating time is between 25 min and 70 min.

6. The preparation method according to any one of claims 1-5, characterized in that, In step S200, the support mesh is placed on the initial functional membrane layer, and then the support mesh is pressed until it is fully embedded in the initial functional membrane layer.

7. The preparation method according to any one of claims 1-5, characterized in that, Specifically, S200 includes: S210: Place the support mesh on the initial functional membrane layer, press the support mesh so that at least part of the support mesh is embedded in the initial functional membrane layer, and heat to obtain a composite substrate; S220: The casting solution is applied again to one side of the support mesh of the composite substrate and heated to cure, thereby obtaining the composite anion exchange membrane.

8. The preparation method according to claim 7, characterized in that, In step S220, the temperature for heating and curing is controlled to be between 60°C and 120°C, and the heating time is between 60 min and 120 min.

9. The preparation method according to claim 1, characterized in that, In step S100, the solid content of the initial functional film layer is controlled to be between 60wt% and 80wt%.

10. A novel composite-enhanced anion exchange membrane, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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