An in-situ generated alkaline electrolyzed water membrane and a method of making the same

Abstract

The application relates to the technical field of composite diaphragms, in particular to an in-situ generated alkaline electrolytic water diaphragm and a preparation method thereof. The diaphragm comprises a polymer matrix which is composed of polysulfone and / or polyethersulfone; the polymer matrix contains in-situ generated layered double metal hydroxide nanoparticles; the preparation method comprises the following steps: firstly, alkaline precursors are added into an organic polar solvent, the pH value of the solution is controlled to be 8-11 to obtain an alkaline polar solution; then, polysulfone or polyethersulfone is dissolved in the alkaline polar solution; subsequently, metal salt precursors are added into the polymer solution to make the layered double metal hydroxide in-situ generated in the polymer solution; the metal salt precursors and the polymer are stirred and mixed; finally, the polymer solution is subjected to casting, phase inversion, post-treatment and then solidification into a film. The application reduces the surface resistance of the diaphragm and improves the chemical stability and long-term operation stability of the composite diaphragm, and has the prospect of large-scale production.

Description

Technical Field

[0001] This invention relates to the field of composite membrane technology, specifically to an in-situ generated alkaline water electrolysis membrane and its preparation method. Background Technology

[0002] Alkaline water electrolysis for hydrogen production is a mature, safe, and reliable green hydrogen production route, crucial for the large-scale development of the hydrogen energy industry. The membrane is one of its core working components, undertaking the dual functions of isolating hydrogen and oxygen gases to prevent mixing and explosion, while simultaneously allowing efficient conduction of hydroxide ions (OH⁻). This directly affects the electrolyzer's operating efficiency, energy consumption, and long-term stability. Therefore, optimizing the performance of the membrane material is a key breakthrough for improving the overall energy efficiency and economy of alkaline water electrolysis systems.

[0003] The conventional approach to applying LDH to membranes is synthesis followed by blending: LDH powder is synthesized first through hydrothermal or co-precipitation methods, and then incorporated into the polymer casting solution through mechanical stirring or ultrasonic dispersion. However, this method suffers from technical problems such as disrupting structural uniformity and easily generating interface issues under complex operating conditions. Moreover, in actual preparation, nano- or micro-sized filler particles are prone to agglomeration, making it difficult to achieve uniform dispersion, and filler particles in traditional composite membranes are prone to detachment (powder shedding).

[0004] Therefore, the industry needs a new material preparation method that can improve the ionic conductivity, mechanical strength and long-term alkaline stability of composite membranes, providing technical support for the development of next-generation high-performance alkaline water electrolysis hydrogen production membranes. Summary of the Invention

[0005] The purpose of this invention is to provide an in-situ generated bimetallic hydroxide composite membrane with strong interfacial bonding, high ion conduction efficiency and simplified preparation process, as well as its preparation method and application.

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

[0007] An in-situ generated alkaline water electrolysis membrane includes a membrane comprising a polymer matrix composed of polysulfone (PSU) and / or polyethersulfone (PES); and further comprising a layered double metal hydroxide (LDH) grown in situ within an alkaline polymer solution of polysulfone and / or polyethersulfone, wherein the layered double metal hydroxide (LDH) accounts for 5-40 wt% of the total mass of the membrane.

[0008] The sheet resistance of the membrane is reduced by ≥15% compared to a pure polymer membrane without layered bimetallic hydroxide (LDH); due to the introduction of layered bimetallic hydroxide (LDH), it forms a continuous multiphase ion conduction channel in the membrane, which increases the OH⁻ mobility by ≥10%; the membrane remains intact and without significant swelling damage after being immersed in 6 M KOH for ≥300 h; the average particle size of the layered bimetallic hydroxide (LDH) is 10–150 nm.

[0009] Preferably, the polysulfone and / or polyethersulfone alkaline polymer solution is prepared by dissolving polysulfone and / or polyethersulfone in an alkaline solution with pH 8-11, wherein the alkaline solution with pH 8-11 is prepared by adding an alkaline precursor to an organic polar solvent; the layered bimetallic hydroxide (LDH) nanoparticles include at least magnesium and aluminum, and are formed by in-situ nucleation and growth of dissolved metal salt precursors in the polysulfone and / or polyethersulfone alkaline polymer solution through a chemical reaction.

[0010] Preferably, the layered bimetallic hydroxide (LDH) accounts for 10-30 wt% of the total mass of the diaphragm.

[0011] Preferably, the metal salt precursor includes anhydrous magnesium chloride (MgCl2, analytical grade) and anhydrous aluminum chloride (AlCl3, analytical grade).

[0012] Preferably, the polymer matrix further includes polyphenylene oxide (PPO), polyarylene ether nitrile (PAEN), polyarylene ether ketone (PAEK), and polyimide (PI).

[0013] Preferably, the diaphragm can be used directly as a self-supporting membrane, or an inner reinforcing layer can be provided according to the actual mechanical strength requirements. The inner reinforcing layer includes, but is not limited to, polyphenylene sulfide (PPS) mesh, polypropylene (PP) mesh, etc., to enhance the structural strength of the diaphragm.

[0014] Preferably, the diaphragm is used in an alkaline water electrolysis hydrogen production device.

[0015] A method for preparing an in-situ generated alkaline water electrolysis membrane, the process flow diagram is shown below. Figure 1 As shown, it includes the following membrane preparation steps:

[0016] S1. Add a basic precursor to an organic polar solvent and control the pH value of the organic polar solvent at 8-11 to obtain an alkaline solution.

[0017] S2. Dissolve polysulfone or polyethersulfone in the alkaline solution prepared in S1, and stir to form a homogeneous and transparent solution to obtain an alkaline polymer solution; wherein the stirring temperature during dissolution is 40-80 ℃, and the stirring time is 4-12 hours.

[0018] S3. Add the metal salt precursor to the polymer solution obtained in S2 and stir to mix the metal salt precursor and the polymer.

[0019] S4. At this point, stir the polymer solution until all the metal salt precursors are dissolved, which promotes the in-situ nucleation and growth of layered bimetallic hydroxides, namely magnesium-aluminum bimetallic hydroxides, in the polymer network, and obtains a composite casting solution containing uniformly dispersed layered bimetallic hydroxide nanoparticles.

[0020] S5. The polymer solution is degassed, cast, and phase-inverted, and then cured into a film. Specifically, the composite casting solution obtained in step S3 is first degassed and then coated on a support to form a liquid film. Then, it is immersed in a non-solvent (such as water) for phase inversion to form a wet film with a microporous structure. Finally, the wet film is washed, dried, and heat-treated to obtain the composite membrane.

[0021] Preferably, the alkaline precursor is one or more of lithium hydroxide, urea, sodium hydroxide, potassium hydroxide, and triethylamine.

[0022] Preferably, the organic polar solvent is one or a combination of N-methylpyrrolidone, N,N-dimethylformamide, or dimethyl sulfoxide.

[0023] The beneficial effects of this invention are as follows:

[0024] The process achieves highly uniform dispersion of LDH nanostructures, fundamentally eliminating filler agglomeration and shedding; it constructs a continuous and efficient three-dimensional ion conduction network, significantly reducing the sheet resistance of the membrane; through strong interfacial interactions, it greatly improves the chemical stability and long-term operational stability of the composite membrane; the process is simple, the raw material cost is low, and it has good potential for large-scale production; while significantly improving ion conduction, it maintains excellent mechanical properties and processability.

[0025] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0026] Figure 1 Schematic diagram of in-situ nucleation of magnesium-aluminum LDH in polymer solution;

[0027] Figure 2 A photograph of the magnesium-aluminum LDH diaphragm in Example 1;

[0028] Figure 3 Scanning electron microscope image of the surface of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1;

[0029] Figure 4 Scanning electron microscope image of the cross-section of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1;

[0030] Figure 5 Tensile strength test diagram of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1;

[0031] Figure 6 Contact angle test diagram of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1;

[0032] Figure 7 Impedance diagram of ionic conductivity test of the cross section of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1 in 1 mol / L KOH solution;

[0033] Figure 8 Blank impedance diagram of the clamp without magnesium-aluminum LDH microporous diaphragm in Example 1;

[0034] Figure 9 Graph of surface resistivity of the in-situ synthesized magnesium-aluminum LDH microporous membrane in Example 1;

[0035] Figure 10 Scanning electron microscope image of LDH powder synthesized in situ;

[0036] Figure 11 TEM image of LDH particles synthesized in situ;

[0037] Figure 12 Schematic diagram of XRD pattern of LDH powder synthesized in situ;

[0038] Figure 13 Thermogravimetric analysis diagram of LDH powder synthesized in situ;

[0039] Figure 14 Scanning electron microscope image of the surface of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 2;

[0040] Figure 15 Scanning electron microscope image of the cross-section of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 2;

[0041] Figure 16 Example 2: Tensile strength test diagram of in-situ synthesized magnesium-aluminum LDH microporous membrane;

[0042] Figure 17 Contact angle test diagram of the in-situ synthesized magnesium-aluminum LDH microporous membrane in Example 2;

[0043] Figure 18 Blank impedance diagram of the clamp without magnesium-aluminum LDH microporous diaphragm in Example 2;

[0044] Figure 19 Graph of surface resistivity test of the in-situ synthesized magnesium-aluminum LDH microporous membrane in Example 2;

[0045] Figure 20 The electrolytic cell performance test diagram of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 1 at 60 °C in 30% KOH;

[0046] Figure 21 Performance test diagram of the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 2 in an electrolyzer at 60 °C in 30% KOH. Detailed Implementation

[0047] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] Example 1: In-situ synthesis of 10 wt% magnesium-aluminum LDH microporous membrane, specifically including the following steps:

[0052] (1) Preparation of a lithium-based solvent system: Weigh 20.00 g of N-methylpyrrolidone (NMP, analytical grade) into a 50 mL beaker as the solvent, and then add 0.48 g of lithium hydroxide (LiOH, analytical grade). Place the beaker on a 60 °C constant-temperature magnetic stirrer, add a magnetic stir bar, and stir continuously at a stirring rate of 300 rpm for 3 hours until the lithium hydroxide is completely dissolved, resulting in a clear lithium-based solution.

[0053] (2) Dissolving the polymer: Add 5.00 g of polysulfone (PSU, grade P-3500) powder to the solution obtained in step S1. Maintain the system temperature at 60 °C, increase the stirring speed to 400 rpm, and continue stirring for 6 hours until the polysulfone is completely dissolved to form a homogeneous, transparent and viscous polymer solution.

[0054] (3) Adding and mixing the metal salt precursor: Under continuous stirring (400 rpm), 0.63 g of anhydrous magnesium chloride (MgCl2, analytical grade) and 0.29 g of anhydrous aluminum chloride (AlCl3, analytical grade) were added sequentially to the above polymer solution. Stirring was continued at 60 °C for 4 hours to ensure complete dissolution and uniform dispersion of the metal salt in the polymer solution, forming a homogeneous and stable casting solution. The mass percentages of each component in this casting solution, calculated by solid content, are approximately: polysulfone 76.1%, MgCl2 9.6%, AlCl3 4.4%, and LiOH 7.3%.

[0055] (4) Casting and Phase Inversion: The casting solution obtained in step S3 was allowed to stand for 30 minutes to degas. Then, on a clean flat glass plate, the casting solution was evenly coated into a film using a doctor blade with a preset gap of 200 μm. The glass plate with the liquid film was immediately immersed in a coagulation bath containing deionized water, and a phase inversion was carried out at room temperature (25 °C). After 10 minutes, a self-supporting wet composite membrane with a microporous structure was peeled off from the glass plate.

[0056] (5) Post-treatment: The obtained wet composite membrane was soaked and washed with a large amount of deionized water for 24 hours to completely remove residual solvents and soluble salts. Then, the membrane was placed in a vacuum drying oven and dried at 60 °C for 24 hours to finally obtain a flexible, light-colored in-situ generated LDH composite membrane.

[0057] Experimental calculations show that the content of magnesium-aluminum bimetallic hydroxide (Mg-Al LDH) generated from the metal salt precursor through in-situ reaction in the composite membrane prepared in this embodiment is about 10% of the membrane dry weight.

[0058] Following the experimental steps described above, the following results were obtained:

[0059] Figure 2 Photo of a magnesium-aluminum LDH microporous diaphragm; Figure 3 Scanning electron microscope image of the surface of the magnesium-aluminum LDH microporous membrane; Figure 4 This is a scanning electron microscope image of the cross-section of a magnesium-aluminum LDH microporous membrane.

[0060] Scanning electron microscopy (SEM) revealed that LDH was uniformly embedded in the polysulfone matrix in a nanosheet structure without significant agglomeration. The sheet resistivity of this film in 30 wt% KOH solution was approximately 35% lower than that of a pure polysulfone reference film of the same thickness.

[0061] Figure 5 The image shows the tensile strength test results of the in-situ synthesized magnesium-aluminum LDH microporous membrane. The sample width is 12.46 mm and the sample thickness is 0.23 mm. It can be seen that the tensile strength of the magnesium-aluminum LDH microporous membrane is 2556.66 kPa.

[0062] Figure 6 The figure shows the contact angle test results of the magnesium-aluminum LDH microporous membrane. As can be seen from the figure, the contact angle of the membrane is 57.7°, which indicates good hydrophilicity.

[0063] Figure 8 The blank impedance diagram is for the clamp without the addition of a magnesium-aluminum LDH microporous diaphragm. Figure 9 The diagram shows the surface resistivity of the magnesium-aluminum LDH microporous membrane. Table 1 shows the surface resistivity test data of the Mg-Al LDH microporous membrane. It can be seen that the surface resistivity of the magnesium-aluminum LDH microporous membrane is 0.0962 Ω cm. 2 The blank group is the group without a diaphragm. The national standard specifies that the surface resistance of the diaphragm is the product of the difference between the resistance value of the diaphragm with the area and the resistance value of the potassium hydroxide solution with the same concentration and area, and the diaphragm area.

[0064]

[0065] As shown in Table 1, the final measured sheet resistivity of the composite diaphragm was 0.0962 Ω cm. 2 The measured thickness of the film is 0.23 mm.

[0066] Table 2 shows the alkali absorption rate test data of the magnesium-aluminum LDH microporous membrane. The method refers to the electronic industry standard SJ / T10171.7-91 "Determination of Alkali Absorption Rate of Membrane" and the alkali absorption rate is about 150%. The high alkali absorption rate of the membrane means that it has a rich microporous structure and hydrophilic groups, which can quickly and massively adsorb and store electrolyte. This reflects that the composite microporous membrane has extremely high alkali absorption capacity and hydrophilicity, which is conducive to the transport of hydroxide ions and the discharge of product gas. Among them, sample H1 and sample H2 are samples of Mg-Al LDH microporous membranes from different batches.

[0067]

[0068] The ionic conductivity of the Mg-Al LDH microporous membrane prepared by the same method in 1 M KOH solution was tested. The membrane thickness was 0.60 mm. Figure 7 As shown, tests were conducted at 20 °C and 40 °C, respectively. The results indicate that the Mg-Al LDH microporous membrane still exhibits good ion conductivity even in low-concentration alkaline solutions. Calculations show that the ion conductivity of the membrane at 20 °C is approximately 687 mS / cm. -2 The ionic conductivity at 40 °C is approximately 932 mS / cm. -2 .

[0069] Figure 20 The figures show the electrolytic cell performance tests of the in-situ synthesized magnesium-aluminum LDH microporous membrane prepared by the same method and the commercial membrane Zirfon UTP 500 in 30% KOH electrolyte at 60 °C. The commercial membrane Zirfon UTP 500 was used as a comparative experimental material. Figure 20 It can be seen that the performance of the in-situ synthesized magnesium-aluminum LDH microporous membrane is superior to that of commercial membranes.

[0070] To investigate the morphology and structural characteristics of the powder itself, magnesium-aluminum bimetallic hydroxide powder was synthesized in situ using a hydrothermal method. Figure 10 Scanning electron microscope image of LDH powder synthesized in situ; Figure 11 Transmission electron microscopy image of LDH powder synthesized in situ; Figure 12 The XRD pattern of LDH powder synthesized in situ; Figure 13 Thermogravimetric analysis diagram of LDH powder synthesized in situ.

[0071] Example 2: In-situ synthesis of 30 wt% magnesium-aluminum LDH microporous membrane, the method is basically the same as that in Example 1, the difference being that the casting solution formulation is changed and the proportion of metal salt is increased; specifically including the following steps:

[0072] (1) Preparation of a lithium-based solvent system: Weigh 50.00 g of N-methylpyrrolidone (NMP, analytical grade) into a 100 mL beaker as a solvent, and then add 1.83 g of lithium hydroxide (LiOH, analytical grade). Place the beaker on a 60 °C constant-temperature heating magnetic stirrer, add a magnetic stir bar, and stir continuously at a stirring rate of 300 rpm for 3 hours until the lithium hydroxide is completely dissolved, resulting in a clear lithium-based solution.

[0073] (2) Dissolving the polymer: Add 5.00 g of polysulfone (PSU, grade P-3500) powder to the solution obtained in step S1. Maintain the system temperature at 60 °C, increase the stirring speed to 400 rpm, and continue stirring for 6 hours until the polysulfone is completely dissolved to form a homogeneous, transparent and viscous polymer solution.

[0074] (3) Adding and mixing the metal salt precursor: Under continuous stirring (400 rpm), add 2.42 g of anhydrous magnesium chloride (MgCl2, analytical grade) and 1.13 g of anhydrous aluminum chloride (AlCl3, analytical grade) to the above polymer solution in sequence. Continue stirring at 60 °C for 4 hours to ensure that the metal salt is completely dissolved and uniformly dispersed in the polymer solution to form a homogeneous and stable casting solution.

[0075] (4) Casting and Phase Inversion: The casting solution obtained in step S3 was allowed to stand for 30 minutes to degas. Then, on a clean flat glass plate, the casting solution was evenly coated into a film using a doctor blade with a preset gap of 200 μm. The glass plate with the liquid film was immediately immersed in a coagulation bath containing deionized water, and a phase inversion was carried out at room temperature (25 °C). After 10 minutes, a self-supporting wet composite membrane with a microporous structure was peeled off from the glass plate.

[0076] (5) Post-treatment: The obtained wet composite membrane was soaked and washed with a large amount of deionized water for 24 hours to completely remove residual solvents and soluble salts. Then, the membrane was placed in a vacuum drying oven and dried at 60 °C for 24 hours to finally obtain a flexible, light-colored in-situ generated LDH composite membrane.

[0077] Experimental calculations show that the content of magnesium-aluminum bimetallic hydroxide (Mg-Al LDH) generated from the metal salt precursor through in-situ reaction in the composite membrane prepared in this embodiment is about 30% of the membrane dry weight.

[0078] Following the experimental steps described above, the following results were obtained:

[0079] Figure 14 Scanning electron microscope image of the surface of the magnesium-aluminum LDH microporous membrane; Figure 15 This is a scanning electron microscope image of the cross-section of a magnesium-aluminum LDH microporous membrane.

[0080] Figure 16 The image shows the tensile strength test results of the in-situ synthesized magnesium-aluminum LDH microporous diaphragm. The sample width is 12.03 mm and the sample thickness is 0.17 mm. The tensile strength of the magnesium-aluminum LDH microporous diaphragm is 1583.28 kPa. Compared to Example 1, the mechanical properties of the diaphragm slightly decrease due to the increased proportion of metal hydroxide, but it is still suitable for the diaphragm frame fixing structure of industrial electrolytic cells.

[0081] Figure 17 The contact angle test diagram of the magnesium-aluminum LDH microporous diaphragm is shown. Figure 17 It can be seen that the contact angle of the diaphragm is 30°, indicating good hydrophilicity;

[0082] Figure 18 The blank impedance diagram is for the clamp without the addition of a magnesium-aluminum LDH microporous diaphragm. Figure 19 The graph shows the surface resistivity of the magnesium-aluminum LDH microporous membrane. Table 3 shows the test data for the surface resistivity of the magnesium-aluminum LDH microporous membrane. It can be seen that the surface resistivity of the magnesium-aluminum LDH microporous membrane is 0.0652 Ω cm. 2 (The blank group is the group without a diaphragm. The national standard specifies the resistance value of the diaphragm with a certain area and the resistance value of a potassium hydroxide solution with the same concentration and area. The product of the difference between the two and the diaphragm area is the surface resistance of the diaphragm.)

[0083] Figure 21 The figures show the electrolytic cell performance test results of the in-situ synthesized magnesium-aluminum LDH microporous membrane and the commercial membrane Zirfon UTP 500 in 30% KOH electrolyte at 60 °C in Example 2. The commercial membrane Zirfon UTP 500 was used as a comparative experimental object. Figure 21 It was found that the magnesium-aluminum LDH microporous membrane synthesized in situ in Example 2 showed significantly better performance than commercial membranes, achieving a current density of 4250 A / m at 1.8 V. -2 It reduces energy consumption by 325% compared to commercial membranes, significantly lowering electrolysis energy consumption.

[0084]

[0085] The sheet resistivity of the composite diaphragm was measured to be 0.0652 Ω cm. 2 The measured thickness of the film is 0.17 mm;

[0086] Table 4 shows the alkali absorption rate test data of the magnesium-aluminum LDH microporous membrane. The method refers to the electronic industry standard SJ / T10171.7-91 "Determination of Alkali Absorption Rate of Membranes", and the alkali absorption rate is about 600%. Compared with Example 1, the increase in the proportion of metal salt in Example 2 significantly improves the alkali absorption rate of the membrane. This means that the membrane can maintain a more sufficient alkaline electrolyte, providing a continuous channel for the transport of hydroxide ions (OH⁻), thereby significantly improving the ionic conductivity of the membrane. This effectively reduces the internal impedance of the battery or electrolytic cell. Among them, sample H1 and sample H2 are samples from different batches of Mg-Al LDH microporous membranes.

[0087]

[0088] In summary:

[0089] This invention proposes an in-situ generation technology that directly reacts magnesium-aluminum bimetallic hydroxide (LDH) nanoparticles in a polymer slurry, allowing the filler and matrix to be integrally formed, fundamentally avoiding the problems of easy detachment and "powdering" common in traditional technologies. The prepared diaphragm features uniform LDH dispersion and strong interfacial bonding, improving the chemical stability and long-term operational stability of the composite diaphragm.

[0090] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An in-situ generated alkaline water electrolysis membrane, characterized in that, The membrane includes a polymer matrix composed of polysulfone and / or polyethersulfone; it also includes a layered bimetallic hydroxide grown in situ within the polysulfone and / or polyethersulfone basic polymer, the layered bimetallic hydroxide comprising 5-40 wt% of the total mass of the membrane, and the layered bimetallic hydroxide nanoparticles comprising at least magnesium and aluminum; The diaphragm is prepared by the following steps: S1. Add an alkaline precursor to an organic polar solvent and control the pH value of the organic polar solvent at 8-11 to obtain an alkaline solution. S2. Dissolve polysulfone or polyethersulfone in the alkaline solution in S1 and stir to obtain an alkaline polymer solution; S3. Add the metal salt precursor to the alkaline polymer solution and stir to mix the metal salt precursor and the polymer. S4. Stir the polymer solution until the metal salt precursor is completely dissolved, which promotes the in-situ nucleation and growth of layered bimetallic hydroxide in the polymer network, and obtains a composite casting solution containing uniformly dispersed layered bimetallic hydroxide nanoparticles. S5. The polymer solution is degassed, cast, phase-inverted, and post-treated, and then cured into a film.

2. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The layered bimetallic hydroxide accounts for 10-30 wt% of the total mass of the diaphragm.

3. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The metal salt precursors include anhydrous magnesium chloride and anhydrous aluminum chloride.

4. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The polymer matrix also includes polyphenylene ether, polyaryletheronitrile, polyaryletherketone, and polyimide.

5. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The diaphragm may have an inner reinforcing layer.

6. The in-situ generated alkaline water electrolysis membrane as described in any one of claims 1-5, characterized in that, The diaphragm is used in an alkaline water electrolysis hydrogen production device.

7. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The alkaline precursor is one or more of lithium hydroxide, urea, sodium hydroxide, potassium hydroxide, and triethylamine.

8. The in-situ generated alkaline water electrolysis membrane as described in claim 1, characterized in that, The organic polar solvent is one or more combinations of N-methylpyrrolidone, N,N-dimethylformamide, or dimethyl sulfoxide.

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