Composite alkaline ion membrane, preparation method and application thereof

Abstract

This invention relates to a composite alkaline ion-exchange membrane, its preparation method, and its applications. The composite alkaline ion-exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion-exchange membrane polymer and an ion-solubilized polymer nanofiber membrane. The quaternized anion-exchange membrane polymer is distributed on the surface and in the pores of the ion-solubilized polymer nanofiber membrane, and the two are covalently bonded together. The preparation method involves coating the surface of the ion-solubilized polymer nanofiber membrane with an anion-exchange membrane polymer solution and filling the pores of the membrane, followed by a crosslinking reaction, a quaternization reaction, and an anion exchange reaction to obtain the composite alkaline ion-exchange membrane. Its applications include using it as an alkaline ion-exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis. The composite alkaline ion-exchange membrane of this invention possesses both excellent ionic conductivity and mechanical strength; the preparation method is simple and easy to implement; and it has a wide range of applications.

Description

Technical Field

[0001] This invention relates to a composite alkaline ion exchange membrane, its preparation method, and its application, belonging to the field of alkaline ion exchange membrane technology. Background Technology

[0002] In today's world, energy shortages and environmental pollution are becoming increasingly prominent, forcing people to accelerate the exploration of new energy sources. Energy-efficient and cost-effective water electrolysis is crucial for the large-scale implementation of renewable energy. Proton exchange membrane water electrolyzers are limited in their widespread application due to the use of expensive perfluorosulfonic acid membranes and precious metal catalysts. Alkaline environments allow water electrolyzers to operate without precious metal catalysts, thus promoting their rapid development in recent years. As a key material in alkaline water electrolyzers, alkaline membranes are currently mainly divided into three categories: traditional porous membranes, anion exchange membranes, and ion-solventizing membranes. Traditional porous membranes are typically composed of stable inert polymers and hydrophilic inorganic fillers (enhancing mechanical properties) and have a porous structure, which facilitates hydroxide ion transport through the high concentration of alkaline solution stored in the pores. However, traditional alkaline water electrolyzers based on porous membranes have relatively thick membranes, resulting in high internal resistance and poor voltage efficiency. Simultaneously, the generated hydrogen and oxygen gases can easily permeate bidirectionally through the porous membrane, resulting in a very low hydrogen production rate and potential safety hazards. Therefore, dense anion exchange membranes and ion-solvated membranes have attracted increasing attention. Anion exchange membranes are typically polymers with fixed cation side groups, where hydroxide ions coordinate with the cation side groups, thereby dissociating and hopping for transport in water. However, anion exchange membranes still face limitations such as low ionic conductivity and insufficient mechanical properties.

[0003] Currently, the common method to improve the ionic conductivity of anion exchange membranes is to increase their ion exchange capacity. However, excessively high ion exchange capacity often leads to excessive water absorption and swelling, which can damage the membrane's mechanical properties. To improve mechanical properties, researchers have introduced a supporting framework into the anion exchange membrane. For example, Chinese patent CN113249980A mixes polyvinyl benzyl chloride, dimethylamino-N-ethyl-N,N-dimethylhexyl-1-amine, and a dispersant, coats the mixture onto a polytetrafluoroethylene membrane, and then hot-presses it into a film. This is followed by ion exchange to obtain a fiber-reinforced anion exchange membrane. However, because this patent uses polytetrafluoroethylene, an inert reinforcing material that cannot conduct hydroxide ions, its ionic conductivity is reduced. Therefore, introducing a reinforcing material with ion transport capabilities is crucial for resolving the trade-off between the ionic conductivity and mechanical properties of anion exchange membranes. Furthermore, optimizing the synergistic effect between the anion exchange membrane and the reinforcing material with ion transport capabilities to further improve its ionic conductivity is also essential.

[0004] Therefore, it is of great significance to study a composite alkaline ion exchange membrane, its preparation method and application, in order to solve the problems existing in the prior art. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a composite alkaline ion exchange membrane, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention adopts the following solution:

[0007] A composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane.

[0008] The quaternized anion exchange membrane polymer is distributed on the surface (preferably on both sides of the surface, but distribution on only one side is also within the scope of protection of this invention) and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded together by covalent bonds.

[0009] As a preferred technical solution:

[0010] As described above, the composite alkaline ion exchange membrane is prepared by halogen modification of polymer A. Polymer A is one or more of polyphenylene ether, polyarylene ether sulfone (PAES), polyarylene ether ketone, polyethylene, polystyrene, polynorbornene, polytetrafluoroethylene, poly(styrene-b-(ethylene-co-butene)-b-styrene) (SEBS), and polysulfone (PSU). The halogen modification method is one or more of chloromethylation and bromhexylation.

[0011] As described above, the composite alkaline ion exchange membrane is prepared by electrospinning of an ion-solventized polymer nanofiber membrane. The ion-solventized polymer is one or more of poly[2,2'-(m-phenyl)-5,5'-bibenzimidazole] (mPBI), poly(2,5-benzimidazole) (ABPBI), and poly(4,4′-diphenyl ether-5,5′-bibenzimidazole) (OPBI).

[0012] The composite alkaline ion exchange membrane described above has a mass fraction of 60-90% in the composite membrane composed of quaternized anion exchange membrane polymer.

[0013] The composite alkaline ion exchange membrane described above has a thickness of 40–50 μm, a tensile strength of 20–50 MPa, a swelling ratio of 8–14% at 80°C, and an ionic conductivity of 50–120 mS / cm at 80°C.

[0014] The composite alkaline ion exchange membrane described above has a thickness of 30–40 μm, a pore size of 0.8–7 μm, and a porosity of 70–90%; the diameter of the ion-solventized polymer nanofibers is 400–2000 nm.

[0015] The present invention also provides a method for preparing a composite alkaline ion exchange membrane as described in any of the preceding claims, wherein an anion exchange membrane polymer solution is coated onto the surface of an ion-solventized polymer nanofiber membrane and filled into the pores of the membrane, and then cross-linking reaction, quaternization reaction and anion exchange reaction are performed sequentially to obtain a composite alkaline ion exchange membrane.

[0016] As a preferred technical solution:

[0017] The preparation method of the composite alkaline ion exchange membrane described above includes the following specific steps:

[0018] (1) After the polymer A, catalyst B and modifying agent C are mixed evenly in solvent D in an ice-water bath, the mixture is reacted at room temperature. After the reaction is completed, the product is precipitated in solvent E and dried to obtain anion exchange membrane polymer.

[0019] (2) Dissolve the anion exchange membrane polymer obtained in step (1) in solvent F, stir at room temperature until completely dissolved to prepare an anion exchange membrane polymer solution;

[0020] (3) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0021] (4) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (3) with the anion exchange membrane polymer solution obtained in step (2) and fill the pores on the membrane;

[0022] (5) The ion-solventized polymer nanofiber membrane coated with the anion exchange membrane polymer solution in step (4) is subjected to a cross-linking reaction. The anion exchange membrane polymer and the ion-solventized polymer nanofiber membrane undergo a cross-linking reaction to achieve covalent bonding and obtain a cross-linked membrane.

[0023] (6) The cross-linked membrane obtained in step (5) is immersed in trimethylamine solution to carry out quaternization reaction. Through the reaction between trimethylamine and the anion exchange membrane polymer in the cross-linked membrane, the halogen groups in the anion exchange membrane polymer are transformed into quaternary ammonium salt functional groups to obtain the quaternized cross-linked membrane, i.e., the composite membrane.

[0024] (7) The composite membrane obtained in step (6) is immersed in sodium hydroxide solution or potassium hydroxide solution to carry out anion exchange reaction, so as to convert the anions in the composite membrane into hydroxide ions and obtain a composite alkaline ion membrane.

[0025] In the preparation method of the composite alkaline ion exchange membrane as described above, in step (1), catalyst B is one or more of anhydrous tin tetrachloride, aluminum trichloride, zinc chloride and concentrated hydrochloric acid (concentration of 37 wt%), modifying agent C is one or more of 1,4-dichloromethoxybutane (BCMB), chloromethyl ether, paraformaldehyde and 6-bromohexanoyl chloride (paraformaldehyde and 6-bromohexanoyl chloride must be used together as modifying agents), solvent D is one or more of chloroform and p-xylene, and solvent E is one or more of methanol, ethanol and propanol; the ratio of the amount of polymer A, catalyst B, modifying agent C, solvent D and solvent E is 1-5 g: 1-4 mL: 5-20 mL: 40-80 mL: 200-500 mL; the reaction time at room temperature is 3-7 h, the drying temperature is 30-80 °C, and the drying time is 24-48 h;

[0026] In step (2), solvent F is a mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1; the concentration of the anion exchange membrane polymer solution is 8–12 wt%; and the dissolution time at room temperature is 10–30 h.

[0027] In step (3), solvent G is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide; the concentration of the ion-solventized polymer in the spinning solution is 10-20 wt%; the electrospinning process parameters are: temperature 25-35℃, humidity 25-35%, voltage 18-24kV, pushing speed 0.1-0.5mL / h, receiving distance 12-16cm; drying temperature is 60-80℃, and drying time is 6-18h.

[0028] In step (5), the temperature of the crosslinking reaction is 60–120°C and the time is 6–18 h;

[0029] In step (6), the concentration of the trimethylamine solution is 30 wt%, and the quaternization reaction time is 48 h;

[0030] In step (7), the concentration of sodium hydroxide solution or potassium hydroxide solution is 1-6M, and the soaking time is 24-100h.

[0031] The present invention also provides the application of a composite alkaline ion exchange membrane as described in any of the preceding claims, used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0032] The mechanism of this invention is as follows:

[0033] Conventional anion exchange membranes are mechanically reinforced by adding inert, non-hydroxyl-conducting reinforcing materials such as polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE). However, adding inert reinforcing materials inevitably results in a loss of ionic conductivity, requiring a trade-off between mechanical strength and ionic conductivity. Unlike conventional reinforcement methods, the composite alkaline ion exchange membrane prepared in this invention possesses both high ionic conductivity and high mechanical strength.

[0034] To improve ionic conductivity, the composite alkaline ion exchange membrane of this invention constructs a unique hydroxide ion conduction mechanism, specifically as follows: In the anion exchange membrane portion of the composite alkaline ion exchange membrane, hydroxide ions are mainly conducted via cationic groups (quaternary ammonium cations) grafted onto the anion exchange membrane backbone. Hydroxide ion transport is achieved through the mutual adsorption and dissociation of cationic groups and hydroxide ions. The ion-solubilized polymer nanofiber membrane in the composite alkaline ion exchange membrane can swell in alkaline solution to form a polymer / alkali / water ternary system for hydroxide ion conduction. Simultaneously, the ion-solubilized polymer nanofiber membrane and the anion exchange membrane polymer in the composite alkaline ion exchange membrane form a two-phase microdomain through chemical cross-linking. This allows for uniform mixing of the cationic groups in the anion exchange membrane and the swollen alkaline solution of the ion-solubilized nanofiber membrane at the molecular scale, thereby constructing a rapid channel for hydroxyl ion conduction through the synergistic interaction of cationic groups and alkaline solution, thus improving ionic conductivity.

[0035] The improved mechanical strength and dimensional stability of the composite anion exchange membrane of this invention come from two aspects: Firstly, the introduced ion-solventized polymer nanofibers themselves possess high mechanical strength. Preparing them in fiber form and adding them to the composite system utilizes the toughness and high strength of the fibers to reinforce the composite membrane. Simultaneously, the anti-swelling properties of the fibers improve the dimensional stability of the composite membrane, enabling it to better resist physical deformation and damage under the actual working environment of the electrolyzer. Secondly, the anion exchange membrane polymer can undergo a cross-linking reaction with the ion-solventized polymer to produce a strong chemical bond. Strong chemical bonds, such as covalent bonds, can significantly improve the interface and compatibility of the two polymers, thereby enhancing the physical stability of the composite anion exchange membrane.

[0036] Beneficial effects:

[0037] (1) The composite alkaline ion exchange membrane of the present invention uses an ion-solventized polymer nanofiber membrane that can conduct hydroxide ions. The two-phase micro-region formed by chemical cross-linking of the nanofiber membrane with the anion exchange membrane polymer can also construct a fast channel for hydroxide ions to conduct through the synergistic conduction of cationic groups and alkaline solution, which significantly improves the ionic conductivity of the composite anion exchange membrane.

[0038] (2) A composite alkaline ion exchange membrane of the present invention uses an ion-solventized polymer nanofiber membrane with high mechanical strength as a reinforcing phase. At the same time, the strong chemical bond between the nanofiber membrane and the anion exchange membrane type polymer significantly improves the interface and compatibility of the two polymers, further enhancing the mechanical strength and anti-swelling performance of the composite anion exchange membrane.

[0039] (3) The preparation method of the composite alkaline ion membrane of the present invention is simple, has a wide range of polymer selectivity, and has high economic benefits.

[0040] (4) The composite alkaline ion membrane of the present invention can be applied to fields such as alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, and electrochemical ammonia synthesis, and has a wide range of applications. Attached Figure Description

[0041] Figure 1 This is a scanning electron microscope image of the surface of the ion-solventized polymer nanofiber membrane in Example 1;

[0042] Figure 2 This is a scanning electron microscope image of the surface of the composite alkaline ion exchange membrane in Example 1;

[0043] Figure 3 This is a cross-sectional scanning electron microscope image of the composite alkaline ion exchange membrane in Example 1. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0045] The test methods involved in the performance indicators in the embodiments and comparative examples of this invention are as follows:

[0046] Tensile strength and elongation at break: The film to be tested was washed or dried according to the test requirements, and then cut into samples with a size of 1×3cm. The tensile strength and elongation at break of the samples were tested using a general-purpose material testing machine of Torizan Corporation of Japan, with a tensile rate of 20mm / min.

[0047] Ionic conductivity: The membrane sample was cut into 1×4cm pieces, washed with deionized water after ion exchange, and the membrane impedance was measured at different temperatures using a Solartron electrochemical workstation with a four-electrode method. The test frequency ranged from 0.1Hz to 100,000Hz. The ionic conductivity was then calculated using the following formula:

[0048]

[0049] Where σ is the ionic conductivity, in S / cm; L is the distance between two adjacent electrodes, in cm; R is the impedance, in Ω; and S is the cross-sectional area, in cm². 2 .

[0050] Swelling rate: Cut the membrane sample into specimens with sides of 2×2cm, immerse them in deionized water at a specified temperature for 5 hours, remove them, wipe off the surface moisture, and record the side length of the wet film. Then, thoroughly dry the specimens in a vacuum oven and record the side length of the dry film. By changing the temperature of the deionized water, the swelling value under different temperature conditions can be calculated using the following formula:

[0051]

[0052] Where SR is the swelling ratio; l 湿 The length of the sample under wet film condition, in cm; l 干 The side length is the sample length when it is completely dried, in cm.

[0053] The sources of some of the materials in this invention are as follows:

[0054] Polyaryl ether sulfone: Manufacturer: Merck Chemical Technology Co., Ltd., Grade: 440965.

[0055] Polysulfone: Manufacturer: Shanghai McLean Biochemical Technology Co., Ltd., Grade: P856835.

[0056] Poly(styrene-b-(ethylene-co-butene)-b-styrene): Manufacturer: Shanghai McLean Biochemical Technology Co., Ltd., Grade: P922032.

[0057] Poly[2,2'-(m-phenyl)-5,5'-bibenzimidazole]: Manufacturer: Shanghai Shengjun Plastics Technology Co., Ltd., Brand: PBISJ-60.

[0058] Poly(2,5-benzimidazole): Manufacturer: Fumatech Technology Co., Ltd., molecular weight 100,000.

[0059] Poly(4,4′-diphenyl ether-5,5′-bibenzimidazole): Manufacturer: Shanghai Shengjun Plastics Technology Co., Ltd., Brand: PBISJ-10.

[0060] Polyethylene: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., Grade: P434351.

[0061] Polynorbornene: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., Grade: P301648.

[0062] Polystyrene: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., Grade: P434446.

[0063] Polytetrafluoroethylene: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., Grade: P434335.

[0064] Paraformaldehyde: Manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., Brand: C104188.

[0065] Example 1

[0066] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0067] (1) Preparation of raw materials:

[0068] Polymer A: Poly(styrene-b-(ethylene-co-butene)-b-styrene) (SEBS);

[0069] Catalyst B: Anhydrous tin tetrachloride;

[0070] Modifying agent C: 1,4-dichloromethoxybutane (BCMB);

[0071] Solvent D: Chloroform;

[0072] Solvent E: Ethanol;

[0073] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0074] Solvent G: N,N-dimethylacetamide;

[0075] Ionically solvated polymer: poly[2,2'-(m-phenyl)-5,5'-bibenzimidazole](mPBI);

[0076] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 3 hours. After the reaction was completed, the product was precipitated in solvent E and dried at 30°C for 24 hours to obtain anion exchange membrane polymer.

[0077] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D, and solvent E is 2g:2.4mL:9.2mL:60mL:350mL.

[0078] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 20 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 11 wt%.

[0079] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0080] The concentration of the ion-solventized polymer in the spinning solution was 15 wt%; the electrospinning process parameters were: temperature 25℃, humidity 25%, voltage 24 kV, pushing speed 0.5 mL / h, receiving distance 12 cm; the drying temperature was 80℃, and the drying time was 6 h.

[0081] The prepared ion-solventized polymer nanofiber membrane has a thickness of 30 μm, a pore size of 1–3 μm, and a porosity of 84%; the diameter of the ion-solventized polymer nanofiber is 500–1500 nm.

[0082] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0083] like Figure 1 As shown, the ion-solventized polymer nanofiber membrane has a uniform thickness and pore size distribution with no obvious defects, and the pores are completely filled by anion exchange membrane polymer.

[0084] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 80°C for 12 h to obtain a cross-linked membrane;

[0085] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0086] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 83 wt%.

[0087] (8) The composite membrane obtained in step (7) is immersed in a 1M potassium hydroxide solution for 24 hours to carry out anion exchange reaction, and a composite alkaline ion exchange membrane is obtained.

[0088] The final composite alkaline ion exchange membrane was obtained by anion exchange of a composite membrane consisting of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane; for example... Figures 2-3As shown, the quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded together by covalent bonds; the composite alkaline ion membrane has a thickness of 40 μm, a tensile strength of 36 MPa, and an ionic conductivity of 120 mS / cm at 80 °C; the swelling ratio of the composite alkaline ion membrane at 80 °C is 12%; the composite alkaline ion membrane is used as an alkaline ion membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0089] Comparative Example 1

[0090] A method for preparing an alkaline ion exchange membrane is basically the same as in Example 1, except that step (4) is omitted and the anion exchange membrane polymer solution obtained in step (3) is directly coated onto a glass plate.

[0091] The final alkaline ion exchange membrane has a tensile strength of 30.3 MPa, an ionic conductivity of 75.2 mS / cm at 80℃, and a swelling ratio of 105.3% at 80℃.

[0092] Comparing Comparative Example 1 and Example 1, it can be found that the tensile strength and ionic conductivity of the composite alkaline ion exchange membrane in Example 1 are higher than those of the alkaline ion exchange membrane in Comparative Example 1. At the same time, the swelling rate of the composite alkaline ion exchange membrane in Example 1 is significantly lower than that in Comparative Example 1. This is because the introduction of fiber structure and the presence of cross-linking in the composite alkaline ion exchange membrane improves the mechanical strength, the optimized ion synergistic conduction effect in the composite alkaline membrane improves the ionic conductivity, and the fiber structure can effectively suppress swelling, thereby improving dimensional stability.

[0093] Comparative Example 2

[0094] A method for preparing an alkaline ion exchange membrane is basically the same as in Example 1, except that: steps (2), (3), (5), (6), and (7) are omitted, and step (4) is carried out directly. The ion-solventized polymer nanofiber membrane obtained in step (4) is immersed in a 1M potassium hydroxide solution for 24 hours to carry out anion exchange reaction, thereby obtaining an alkaline ion exchange membrane.

[0095] The final alkaline ion exchange membrane has a tensile strength of 21.5 MPa and an ionic conductivity of 15.8 mS / cm at 80 °C.

[0096] Comparing Comparative Example 2 and Example 1, it can be found that the tensile strength and ionic conductivity of the composite alkaline ion exchange membrane in Example 1 are higher than those in Comparative Example 2. This is because the alkaline ion exchange membrane in Comparative Example 2 is porous and has low mechanical strength. At the same time, it is insufficient in absorbing alkali and water at low alkali concentrations, resulting in insufficient ionic conductivity. In contrast, the pores of the composite alkaline ion exchange membrane in Example 1 are filled and cross-linked, which improves mechanical strength. The optimized ion transport pathway improves ionic conductivity.

[0097] Example 2

[0098] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0099] (1) Preparation of raw materials:

[0100] Polymer A: Polyarylene ether sulfone (PAES);

[0101] Catalyst B: Aluminum trichloride;

[0102] Modifying agent C: Chloromethyl ether;

[0103] Solvent D: Chloroform;

[0104] Solvent E: Ethanol;

[0105] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0106] Solvent G: N,N-dimethylacetamide;

[0107] Ionically solvated polymer: poly(4,4′-diphenyl ether-5,5′-bibenzimidazole) (OPBI);

[0108] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 5 hours. After the reaction was completed, the product was precipitated in solvent E and dried at 80°C for 24 hours to obtain anion exchange membrane polymer.

[0109] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D, and solvent E is 2g:2.4mL:20mL:60mL:350mL.

[0110] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 30 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 8 wt%.

[0111] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0112] The concentration of the ion-solventized polymer in the spinning solution was 10 wt%; the electrospinning process parameters were: temperature 35℃, humidity 35%, voltage 18kV, pushing speed 0.1mL / h, receiving distance 16cm; the drying temperature was 60℃, and the drying time was 18h.

[0113] The prepared ion-solventized polymer nanofiber membrane has a thickness of 34 μm, a pore size of 0.8–1.5 μm, and a porosity of 90%; the diameter of the ion-solventized polymer nanofiber is 400–800 nm.

[0114] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0115] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 60°C for 18 h to obtain a cross-linked membrane;

[0116] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0117] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 90 wt%.

[0118] (8) The composite membrane obtained in step (7) is immersed in a 3M potassium hydroxide solution for 48 hours to carry out anion exchange reaction, and a composite alkaline ion exchange membrane is obtained.

[0119] The final composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane. The quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded by covalent bonds. The composite alkaline ion exchange membrane has a thickness of 42 μm, a tensile strength of 20 MPa, and an ionic conductivity of 94 mS / cm at 80 °C. The swelling ratio of the composite alkaline ion exchange membrane at 80 °C is 13.5%. The composite alkaline ion exchange membrane is used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0120] Comparative Example 3

[0121] A method for preparing an alkaline ion exchange membrane is basically the same as in Example 2, except that step (4) is omitted and the anion exchange membrane polymer solution obtained in step (3) is directly coated onto a glass plate.

[0122] The final alkaline ion exchange membrane has a tensile strength of 16.7 MPa, an ionic conductivity of 49.6 mS / cm at 80℃, and a swelling ratio of 18.8% at 80℃.

[0123] Comparing Comparative Example 3 and Example 2, it can be found that the tensile strength and ionic conductivity of the composite alkaline ion exchange membrane in Example 2 are higher than those of the alkaline ion exchange membrane in Comparative Example 3. The swelling rate in Example 2 is significantly lower than that in Comparative Example 3. This is because, compared with Comparative Example 3, the introduction of fiber structure and the presence of cross-linking in the composite alkaline ion exchange membrane in Example 2 improve the mechanical strength, the optimized ion synergistic conduction effect in the composite alkaline ion exchange membrane improves the ionic conductivity, and the fiber structure in the composite alkaline ion exchange membrane effectively inhibits swelling.

[0124] Example 3

[0125] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0126] (1) Preparation of raw materials:

[0127] Polymer A: Polysulfone (PSU);

[0128] Catalyst B: Zinc chloride;

[0129] Modifying reagent C: paraformaldehyde and 6-bromohexanoyl chloride in a 1:1 mass ratio;

[0130] Solvent D: Chloroform;

[0131] Solvent E: Ethanol;

[0132] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0133] Solvent G: N,N-dimethylacetamide;

[0134] Ionically solvated polymer: poly(2,5-benzimidazole) (ABPBI);

[0135] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 7 hours. After the reaction was completed, the product was precipitated in solvent E and dried at 30°C for 24 hours to obtain anion exchange membrane polymer.

[0136] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D, and solvent E is 2g:2.4mL:10mL:60mL:350mL.

[0137] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 10 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 9 wt%.

[0138] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0139] The concentration of the ion-solventized polymer in the spinning solution was 20 wt%; the electrospinning process parameters were: temperature 30℃, humidity 30%, voltage 20 kV, pushing speed 0.2 mL / h, receiving distance 12 cm; the drying temperature was 70℃, and the drying time was 12 h.

[0140] The prepared ion-solventized polymer nanofiber membrane has a thickness of 36 μm, a pore size of 4–7 μm, and a porosity of 70%; the diameter of the ion-solventized polymer nanofiber is 800–2000 nm.

[0141] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0142] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 120°C for 6 hours to obtain a cross-linked membrane;

[0143] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0144] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 60%.

[0145] (8) The composite membrane obtained in step (7) is immersed in a 6M potassium hydroxide solution for 100 hours to carry out anion exchange reaction, thereby obtaining a composite alkaline ion exchange membrane.

[0146] The final composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane. The quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded by covalent bonds. The composite alkaline ion exchange membrane has a thickness of 44 μm, a tensile strength of 32 MPa, and an ionic conductivity of 106 mS / cm at 80 °C. The swelling ratio of the composite alkaline ion exchange membrane at 80 °C is 8%. The composite alkaline ion exchange membrane is used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0147] Comparative Example 4

[0148] A method for preparing an alkaline ion exchange membrane is basically the same as in Example 3, except that step (4) is omitted and the anion exchange membrane polymer solution obtained in step (3) is directly coated onto a glass plate.

[0149] The final alkaline ion exchange membrane has a tensile strength of 27.5 MPa, an ionic conductivity of 47.1 mS / cm at 80℃, and a swelling ratio of 22.8% at 80℃.

[0150] Comparing Comparative Example 4 and Example 3, it can be found that the tensile strength and ionic conductivity of the composite alkaline ion exchange membrane in Example 3 are higher than those of the alkaline ion exchange membrane prepared by the anion exchange membrane polymer used. At the same time, the swelling rate in Example 3 is significantly reduced. This is because, compared with Comparative Example 4, the introduction of fiber structure and the presence of cross-linking in the composite alkaline ion exchange membrane in Example 3 improve the mechanical strength, the optimized ion synergistic conduction effect in the composite alkaline membrane improves the ionic conductivity, and the fiber structure in the composite alkaline ion exchange membrane effectively inhibits swelling, thereby improving dimensional stability.

[0151] Example 4

[0152] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0153] (1) Preparation of raw materials:

[0154] Polymer A: Polyethylene;

[0155] Catalyst B: Zinc chloride and concentrated hydrochloric acid (37 wt%);

[0156] Modifying reagent C: paraformaldehyde and 6-bromohexanoyl chloride in a 1:1 mass ratio;

[0157] Solvent D: p-xylene;

[0158] Solvent E: Methanol;

[0159] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0160] Solvent G: N,N-dimethylformamide;

[0161] Ionically solvated polymer: poly[2,2'-(m-phenyl)-5,5'-bibenzimidazole];

[0162] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 5 hours. After the reaction was completed, the product was precipitated in solvent E and dried at 60°C for 32 hours to obtain anion exchange membrane polymer.

[0163] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D and solvent E is 1g:1mL:5mL:40mL:200mL.

[0164] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 10 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 12 wt%.

[0165] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0166] The concentration of the ion-solventized polymer in the spinning solution was 20 wt%; the electrospinning process parameters were: temperature 28℃, humidity 25%, voltage 24 kV, pushing speed 0.2 mL / h, receiving distance 12 cm; the drying temperature was 80℃, and the drying time was 12 h.

[0167] The prepared ion-solventized polymer nanofiber membrane has a thickness of 38 μm, a pore size of 2–5 μm, and a porosity of 76%; the diameter of the ion-solventized polymer nanofiber is 700–1800 nm.

[0168] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0169] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 90°C for 8 hours to obtain a cross-linked membrane;

[0170] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0171] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 74 wt%.

[0172] (8) The composite membrane obtained in step (7) is immersed in a 1M sodium hydroxide solution for 48 hours to carry out anion exchange reaction, thereby obtaining a composite alkaline ion exchange membrane.

[0173] The final composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane. The quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded by covalent bonds. The composite alkaline ion exchange membrane has a thickness of 45 μm, a tensile strength of 28 MPa, and an ionic conductivity of 50 mS / cm at 80 °C. The swelling ratio of the composite alkaline ion exchange membrane at 80 °C is 9.2%. The composite alkaline ion exchange membrane is used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0174] Example 5

[0175] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0176] (1) Preparation of raw materials:

[0177] Polymer A: Polystyrene and polynorbornene in a 1:1 mass ratio;

[0178] Catalyst B: Anhydrous tin tetrachloride and aluminum trichloride in a 1:1 mass ratio;

[0179] Modifying agent C: 1,4-dichloromethoxybutane and chloromethyl ether in a mass ratio of 1:1;

[0180] Solvent D: Chloroform and p-xylene in a 1:1 mass ratio;

[0181] Solvent E: Methanol and ethanol in a 1:1 volume ratio;

[0182] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0183] Solvent G: Dimethyl sulfoxide;

[0184] Ionically solvated polymer: poly(2,5-benzimidazole);

[0185] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 6 hours. After the reaction was completed, the product was precipitated in solvent E and dried at 80°C for 24 hours to obtain anion exchange membrane polymer.

[0186] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D, and solvent E is 2g:1.4mL:9.2mL:60mL:400mL.

[0187] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 20 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 10 wt%.

[0188] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0189] The concentration of the ion-solventized polymer in the spinning solution was 20 wt%; the electrospinning process parameters were: temperature 28℃, humidity 25%, voltage 24 kV, pushing speed 0.2 mL / h, receiving distance 16 cm; the drying temperature was 80℃, and the drying time was 12 h.

[0190] The prepared ion-solventized polymer nanofiber membrane has a thickness of 40 μm, a pore size of 2–6 μm, and a porosity of 74%; the diameter of the ion-solventized polymer nanofiber is 600–1700 nm.

[0191] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0192] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 120°C for 12 h to obtain a cross-linked membrane;

[0193] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0194] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 79 wt%.

[0195] (8) The composite membrane obtained in step (7) is immersed in a 3M sodium hydroxide solution for 72 hours to carry out anion exchange reaction, thereby obtaining a composite alkaline ion exchange membrane.

[0196] The final composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane. The quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded by covalent bonds. The composite alkaline ion exchange membrane has a thickness of 48 μm, a tensile strength of 50 MPa, and an ionic conductivity of 76 mS / cm at 80 °C. The swelling ratio of the composite alkaline ion exchange membrane at 80 °C is 10.6%. The composite alkaline ion exchange membrane is used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

[0197] Example 6

[0198] A method for preparing a composite alkaline ion-exchange membrane, the specific steps of which are as follows:

[0199] (1) Preparation of raw materials:

[0200] Polymer A: polytetrafluoroethylene and poly(styrene-b-(ethylene-co-butene)-b-styrene) in a 1:1 mass ratio;

[0201] Catalyst B: Aluminum trichloride and zinc chloride in a 1:1 mass ratio;

[0202] Modifying reagent C: chloromethyl ether, paraformaldehyde, and 6-bromohexanoyl chloride in a mass ratio of 2:1:1;

[0203] Solvent D: Chloroform and p-xylene in a 1:1 mass ratio;

[0204] Solvent E: Ethanol and propanol in a 1:1 volume ratio;

[0205] Solvent F: A mixture of chloroform and p-xylene, with a mass ratio of chloroform to p-xylene of 2:1;

[0206] Solvent G: N,N-dimethylformamide and dimethyl sulfoxide in a 1:1 volume ratio;

[0207] Ionically solvated polymers: poly(2,5-benzimidazole) (ABPBI) and poly(4,4′-diphenyl ether-5,5′-bibenzimidazole) in a 1:1 mass ratio;

[0208] (2) After mixing polymer A, catalyst B and modifying agent C in solvent D in an ice-water bath, the mixture was reacted at room temperature for 7 h. After the reaction was completed, the product was precipitated in solvent E and dried at 30 °C for 48 h to obtain anion exchange membrane polymer.

[0209] The ratio of the amounts of polymer A, catalyst B, modifying agent C, solvent D, and solvent E is 5g:4mL:20mL:80mL:500mL.

[0210] (3) Dissolve the anion exchange membrane polymer obtained in step (2) in solvent F, stir at room temperature for 30 h to completely dissolve and prepare an anion exchange membrane polymer solution with a concentration of 10 wt%.

[0211] (4) The ion-solventized polymer is dissolved in solvent G to prepare a spinning solution. After heating and stirring until completely dissolved, electrospinning is performed, and then drying is carried out to obtain an ion-solventized polymer nanofiber membrane.

[0212] The concentration of the ion-solventized polymer in the spinning solution was 10 wt%; the electrospinning process parameters were: temperature 28℃, humidity 25%, voltage 24 kV, pushing speed 0.2 mL / h, receiving distance 12 cm; the drying temperature was 80℃, and the drying time was 12 h.

[0213] The prepared ion-solventized polymer nanofiber membrane has a thickness of 40 μm, a pore size of 1–2 μm, and a porosity of 86%; the diameter of the ion-solventized polymer nanofiber is 400–1000 nm.

[0214] (5) Coat the surface of the ion-solventized polymer nanofiber membrane prepared in step (4) with the anion exchange membrane polymer solution obtained in step (3) and fill the pores on the membrane. The coating thickness is 40 μm.

[0215] (6) The ion-solventized polymer nanofiber membrane coated with anion exchange membrane polymer solution in step (5) is subjected to cross-linking reaction at 60°C for 16 h to obtain a cross-linked membrane;

[0216] (7) The cross-linked membrane obtained in step (6) was immersed in a 30 wt% trimethylamine aqueous solution for quaternization reaction for 48 h to obtain a composite membrane;

[0217] The mass fraction of the quaternized anion exchange membrane polymer in the composite membrane is 89 wt%.

[0218] (8) The composite membrane obtained in step (7) is immersed in a 6M potassium hydroxide solution for 24 hours to carry out anion exchange reaction, thereby obtaining a composite alkaline ion exchange membrane.

[0219] The final composite alkaline ion exchange membrane is obtained by anion exchange of a composite membrane composed of a quaternized anion exchange membrane polymer and an ion-solventized polymer nanofiber membrane. The quaternized anion exchange membrane polymer is distributed on the surface and in the pores of the ion-solventized polymer nanofiber membrane, and the two are bonded by covalent bonds. The composite alkaline ion exchange membrane has a thickness of 50 μm, a tensile strength of 24 MPa, and an ionic conductivity of 55 mS / cm at 80 °C. The swelling rate of the composite alkaline ion exchange membrane at 80 °C is 14%. The composite alkaline ion exchange membrane is used as an alkaline ion exchange membrane in alkaline water electrolysis for hydrogen production, alkaline fuel cells, carbon dioxide conversion, or electrochemical ammonia synthesis.

Claims

1. A composite alkaline ion exchange membrane, characterized by: The composite membrane is obtained by anion exchange of a composite membrane composed of a quaternary aminated anion exchange membrane type polymer and an ionic solvated polymer nanofiber membrane; The quaternary aminated anion exchange membrane type polymer is distributed on the surface and in the pores of the ionic solvated polymer nanofiber membrane, and is covalently bonded to the ionic solvated polymer nanofiber membrane; The anion exchange membrane type polymer is prepared by halogen modification of a polymer A, the polymer A being one or more of polyphenylene ether, polyarylene ether sulfone, polyarylene ether ketone, polyethylene, polystyrene, polynorbornene, polytetrafluoroethylene, poly(styrene-b-(ethylene-co-butylene)-b-styrene), and polysulfone, and the halogen modification being one or more of chloromethylation and bromohexylation; The ionic solvated polymer nanofiber membrane is prepared by electrospinning of an ionic solvated polymer, the ionic solvated polymer being one or more of poly[2,2'-(m-phenyl)-5,5'-biphenyl imidazole], poly(2,5-benzimidazole), and poly(4,4'-diphenyl ether-5,5'-biphenyl imidazole); The composite alkaline ion membrane has a thickness of 40-50 μm, a tensile strength of 20-50 MPa, a swelling rate of 8-14% at 80°C, and an ionic conductivity of 50-120 mS / cm at 80°C.

2. The composite basic ion-exchange membrane according to claim 1, wherein The quaternary aminated anion exchange membrane type polymer in the composite membrane has a mass fraction of 60-90%.

3. The composite basic ion-exchange membrane according to claim 1, wherein The ionic solvated polymer nanofiber membrane has a thickness of 30-40 μm, a pore size of 0.8-7 μm, and a porosity of 70-90%; and the ionic solvated polymer nanofiber has a diameter of 400-2000 nm.

4. The method for preparing a composite alkaline ion-exchange membrane according to any one of claims 1 to 3, characterized by: The anion exchange membrane type polymer solution is coated on the surface of the ionic solvated polymer nanofiber membrane and filled into the pores of the membrane, followed by crosslinking, quaternization, and anion exchange to obtain the composite alkaline ion membrane.

5. The method of claim 4 wherein the method further comprises the step of: The specific preparation steps are as follows: (1) The polymer A, catalyst B, and modification reagent C are mixed uniformly in solvent D in an ice water bath, and then reacted at room temperature. After the reaction is completed, the product is precipitated in solvent E, and then dried to obtain the anion exchange membrane type polymer; (2) The anion exchange membrane type polymer obtained in step (1) is dissolved in solvent F, and then stirred at room temperature until completely dissolved to obtain an anion exchange membrane type polymer solution; (3) The ionic solvated polymer is dissolved in solvent G to prepare a spinning solution, which is heated and stirred until completely dissolved, and then electrospun, and then dried to obtain the ionic solvated polymer nanofiber membrane; (4) The anion exchange membrane type polymer solution obtained in step (2) is coated on the surface of the ionic solvated polymer nanofiber membrane prepared in step (3) and filled into the pores of the membrane; (5) The ionic solvated polymer nanofiber membrane coated with the anion exchange membrane type polymer solution in step (4) is subjected to crosslinking to obtain a crosslinked membrane; (6) The crosslinked membrane obtained in step (5) is immersed in a trimethylamine solution for quaternization to obtain the composite membrane. (7) soaking the composite membrane obtained in step (6) in a sodium hydroxide solution or a potassium hydroxide solution to perform an anion exchange reaction, thereby obtaining a composite alkaline ion membrane.

6. The method of claim 5 wherein the method further comprises the step of: In step (1), the catalyst B is one or more of anhydrous tin tetrachloride, aluminum trichloride, zinc chloride, and concentrated hydrochloric acid, the modification reagent C is one or more of 1,4-dichloromethoxybutane, chloromethyl ether, paraformaldehyde, and 6-bromohexanoyl chloride, the solvent D is one or more of chloroform and p-xylene, and the solvent E is one or more of methanol, ethanol, and propanol; the ratio of the amounts of the polymer A, the catalyst B, the modification reagent C, the solvent D, and the solvent E is 1-5 g: 1-4 mL: 5-20 mL: 40-80 mL: 200-500 mL; the reaction time at room temperature is 3-7 h, the drying temperature is 30-80 ℃, and the drying time is 24-48 h; In step (2), the solvent F is a mixture of chloroform and p-xylene, the mass ratio of chloroform to p-xylene is 2:1, the concentration of the anion exchange membrane type polymer solution is 8-12 wt%, and the stirring and dissolving time at room temperature is 10-30 h; In step (3), the solvent G is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide; the concentration of the ionic solvated polymer in the spinning solution is 10-20 wt%; the electrospinning process parameters are as follows: temperature 25-35 ℃, humidity 25-35%, voltage 18-24 kV, push speed 0.1-0.5 mL / h, and receiving distance 12-16 cm; the drying temperature is 60-80 ℃, and the drying time is 6-18 h; In step (5), the crosslinking reaction temperature is 60-120 ℃, and the time is 6-18 h; In step (6), the concentration of the trimethylamine solution is 30 wt%, and the quaternization reaction time is 48 h; In step (7), the concentration of the sodium hydroxide solution or the potassium hydroxide solution is 1-6 M, and the soaking time is 24-100 h.

7. Use of a composite alkaline ion-exchange membrane according to any one of claims 1 to 3, characterized in that: The composite alkaline ion membrane is used in the production of hydrogen by alkaline electrolysis of water, alkaline fuel cells, carbon dioxide conversion, or electrochemical synthesis of ammonia.

Images