Solid electrolyte membrane for hydrogen production by alkaline electrolyzed water and preparation method and application thereof

Abstract

The invention relates to a solid electrolyte membrane for hydrogen production from alkaline electrolyzed water and a preparation method and application thereof, the solid electrolyte membrane comprises an anion exchange membrane and coatings arranged on the two sides of the anion exchange membrane, and a'coating-anion exchange membrane-coating 'sandwich composite structure is formed; the coating includes a mixture of a thermoplastic resin and hydrophilic inorganic nanoparticles. The preparation method comprises the following steps: respectively preparing coating slurry and anion exchange membrane slurry; coating the coating slurry on a transfer printing substrate, and drying to obtain a transfer printing substrate / coating; coating the coating slurry and the anion exchange membrane slurry on a transfer printing substrate in sequence, and drying to obtain a transfer printing substrate / coating / anion exchange membrane; and thermal transfer printing. Compared with the prior art, swelling deformation and damage of the anion exchange membrane can be effectively prevented, the mechanical property and stability of the anion exchange membrane are improved, and meanwhile the problem that the air tightness of the composite membrane is limited is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of anion exchange membrane preparation, and in particular to a solid electrolyte membrane for alkaline water electrolysis hydrogen production, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, extreme weather has occurred frequently, and people have paid more and more attention to environmental protection and governance. Terms such as "carbon emission" have become hot topics in our country. The country urgently needs reliable clean energy to replace traditional fossil energy. Hydrogen energy has the characteristics of rich sources, pollution-free, and wide application, and is an important part of the national energy strategic transformation. As the most efficient current solution for "green hydrogen" production, water electrolysis hydrogen production technology is the key link to achieve zero carbon emissions throughout the process of hydrogen production and use. Among them, anion exchange membrane water electrolysis hydrogen production technology fully combines the advantages of alkaline water electrolysis technology and proton exchange membrane water electrolysis hydrogen production technology, and is expected to become the most promising renewable energy hydrogen production technology.

[0003] Anion exchange membranes are essential components in anion exchange membrane water electrolysis hydrogen production systems. They are mainly responsible for isolating the generated hydrogen and oxygen, preventing hydrogen-oxygen intermixing from causing an explosion, and also avoiding short circuits between the cathode and anode. Compared with mainstream alkaline water electrolysis systems, anion exchange membrane water electrolysis hydrogen production systems generally have better electrochemical performance and lower energy consumption. This is due to the functional groups of anion exchange membrane resins that can transfer hydroxide ions and their excellent hydrophilicity. However, the excellent hydrophilicity causes problems such as swelling deformation and poor dimensional stability in the actual use of anion exchange membranes, resulting in a significant decline in mechanical properties and a reduction in service life. In addition, the problem of damage to anion exchange membranes frequently occurs during the assembly process. Due to limitations in the preparation process or to increase the reaction interface area, the electrode surface is usually designed to be relatively rough. However, the thickness of anion exchange membranes is usually only a few tens of micrometers. Therefore, under the action of a rough electrode surface, they are easily punctured. This physical damage will directly affect the stability and safety of the water electrolysis system, possibly leading to a decrease in electrolysis efficiency and even causing safety accidents.

[0004] Patent CN 118996525 A discloses a preparation method of a highly stable ultra-thin composite diaphragm for an alkaline water electrolyzer. The method includes mixing a thermoplastic resin and a hydrophilic inorganic nanoparticle to obtain a casting solution, roughening a support mesh substrate by an adhesion-peeling method, then coating the casting solution and performing phase inversion. Finally, an ultra-thin composite diaphragm with good stability and low surface resistance is obtained. However, due to limitations in the pore structure and preparation process, the airtightness of this type of composite diaphragm has an upper limit, which is far inferior to that of anion exchange membranes. It cannot adapt to operating conditions with large air pressure fluctuations, and is prone to cortical damage during packaging, transportation, and assembly, resulting in the failure of the composite diaphragm. Summary of the Invention

[0005] The object of the present invention is to provide a solid electrolyte membrane for alkaline electrolytic water hydrogen production, its preparation method and application, which can effectively prevent the swelling deformation and damage of the anion exchange membrane, improve the mechanical properties and stability of the anion exchange membrane, and at the same time solve the problem of limited airtightness of the composite diaphragm.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] In the first aspect, the present invention provides a solid electrolyte membrane for alkaline electrolytic water hydrogen production, which includes an anion exchange membrane and coatings provided on both sides of the anion exchange membrane, forming a "sandwich" composite structure of "coating - anion exchange membrane - coating", and the coating includes a mixture of a thermoplastic resin and hydrophilic inorganic nanoparticles.

[0008] Preferably, the thickness of the anion exchange membrane is 10 - 200 μm, and the thickness of the coatings on both sides is 0.5 - 3 times the thickness of the anion exchange membrane.

[0009] Preferably, the anion exchange membrane is prepared from an anion exchange membrane resin, and the anion exchange membrane resin includes one or more of quaternized polysulfone, quaternized polyphenylene ether, quaternized polybenzimidazole, quaternized polystyrene, alkylated polybenzimidazole, polyarylpiperidine, and polyarylquinine.

[0010] Preferably, the thermoplastic resin includes one or more of polysulfone, polyethersulfone, polyphenylene sulfide, polypropylene, polyetheretherketone, polyimide, and polyetherimide.

[0011] Preferably, the particle size of the hydrophilic inorganic nanoparticles is 30 - 100 nm, and includes one or more of zirconia, ceria, titania, and barium sulfate.

[0012] In the second aspect, the present invention provides a preparation method of the solid electrolyte membrane for alkaline electrolytic water hydrogen production as described above, including the following steps:

[0013] S1: Prepare coating slurry and anion exchange membrane slurry respectively;

[0014] S2: Coat the coating slurry on a transfer substrate, and obtain a transfer substrate / coating after drying;

[0015] S3: Coat the coating slurry and the anion exchange membrane slurry on the transfer substrate in sequence, and obtain a transfer substrate / coating / anion exchange membrane after drying;

[0016] S4: Thermal transfer.

[0017] Preferably, in step S1, the preparation process of the coating slurry includes the following steps: dissolving a thermoplastic resin and a hydrophilic inorganic nanoparticle in an organic solvent, and mixing them evenly to obtain the coating slurry.

[0018] Further preferably, in step S1, the mass ratio of the thermoplastic resin to the organic solvent is 1:9 - 1:1, and the mass ratio of the thermoplastic resin to the hydrophilic inorganic nanoparticle is 1:10 - 10:3.

[0019] Further preferably, in step S1, the mixing is carried out evenly by means of mechanical stirring or dispersion methods such as ball milling and ultrasonic treatment.

[0020] Preferably, in step S1, the preparation process of the anion exchange membrane slurry includes the following steps: dissolving an anion exchange membrane resin in an organic solvent, and obtaining the anion exchange membrane slurry after dissolution.

[0021] Further preferably, in step S1, the content of the anion exchange membrane resin in the organic solvent is 10 - 50 wt%.

[0022] Further preferably, in step S1, the organic solvents in the coating slurry and the anion exchange membrane slurry include one or more of N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, formamide, and N,N-dimethylacetamide.

[0023] Preferably, in steps S2 and S3, the transfer substrate includes any one of a polypropylene film, a polyethylene film, and a polytetrafluoroethylene film.

[0024] Further preferably, in step S2, a doctor blade or a coating head is used to coat the coating slurry.

[0025] Further preferably, in step S3, a spray gun, a doctor blade or a coating head is used to coat the anion exchange membrane slurry.

[0026] Preferably, in steps S2 and S3, the drying temperature is 50 - 90 °C, and the time is more than 3 hours.

[0027] Further preferably, in step S3, after coating the coating slurry on the transfer substrate and drying it, the anion exchange membrane slurry is coated, and after drying again, the transfer substrate / coating / anion exchange membrane is obtained.

[0028] Preferably, in step S4, the specific process of thermal transfer is: thermally pressing the transfer substrate / coating and the printing substrate / coating / anion exchange membrane together, waiting for cooling to room temperature, and removing the transfer substrates on both sides to obtain the solid electrolyte membrane for alkaline electrolytic water hydrogen production.

[0029] Further preferably, in step S4, the temperature of the hot pressing is 100-200 °C, the pressure is 0.1-10 MPa, and the time is 1-20 minutes.

[0030] Further preferably, the method for preparing the solid electrolyte membrane for alkaline electrolytic water hydrogen production includes the following steps:

[0031] S1: Dissolve the thermoplastic resin in an organic solvent, then add hydrophilic inorganic nanoparticles, and mix evenly by mechanical stirring, ball milling, ultrasonic dispersion or other dispersion methods to obtain a coating slurry; dissolve the anion exchange membrane resin in an organic solvent, and fully dissolve it to obtain an anion exchange membrane slurry.

[0032] S2: Coat the coating slurry on the transfer substrate with a doctor blade or a coating head, and then put it into an oven to evaporate the organic solvent.

[0033] S3: Coat the anion exchange membrane slurry on the transfer substrate coated with the coating slurry with a spray gun, a doctor blade or a coating head, and then put it into an oven to evaporate the organic solvent.

[0034] S4: Thermally press the coating with the anion exchange membrane and the coating without the anion exchange membrane together with a hot press. After the coating is cooled to room temperature, remove the transfer substrates on both sides to obtain a solid electrolyte membrane for alkaline electrolytic water hydrogen production.

[0035] In a third aspect, the present invention also provides an application of the solid electrolyte membrane for alkaline electrolytic water hydrogen production in alkaline electrolytic water hydrogen production.

[0036] The present invention provides a solid electrolyte membrane for alkaline electrolytic water hydrogen production and a preparation method thereof. Stable coatings that do not swell, are hard and wear-resistant are prepared on both sides of the anion exchange membrane to form a "sandwich" composite structure of "coating - anion exchange membrane - coating", which restricts the deformation of the middle anion exchange membrane. At the same time, the anion exchange membrane in the middle position of the electrolyte membrane provides excellent airtightness for the electrolyte membrane. The coating in the present invention is mainly composed of a thermoplastic resin and hydrophilic inorganic nanoparticles. The thermoplastic resin is the main body of the coating and is closely connected to the anion exchange membrane, while the hydrophilic inorganic nanoparticles are responsible for compensating for the poor hydrophilicity of the thermoplastic resin and reducing the influence of the coating on the electrochemical performance of the anion exchange membrane.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention provides a solid electrolyte membrane for alkaline electrolytic water hydrogen production, which includes an anion exchange membrane and coatings provided on both sides of the anion exchange membrane. The coating includes a mixture of a thermoplastic resin and hydrophilic inorganic nanoparticles. This coating greatly limits the swelling deformation of the anion exchange membrane by virtue of its excellent mechanical properties and stability, and at the same time compensates for the drawback of the decreased mechanical properties of the anion exchange membrane after swelling, solving the problem of limited airtightness of the composite diaphragm.

[0039] (2) The present invention forms a "sandwich" composite structure of "coating - anion exchange membrane - coating" by coating coatings on both sides of the anion exchange membrane. The coating has wear resistance and can act as a protective layer for the anion exchange membrane. The wear-resistant coating can effectively prevent the sharp parts on the electrode surface from directly contacting the thinner anion exchange membrane, ensuring the integrity of the anion exchange membrane and the stability of the airtightness of the electrolyte membrane.

[0040] (3) Compared with commercial products of organic-inorganic composite diaphragms, the airtightness of the present invention is more excellent, and the purities of hydrogen and oxygen prepared in the alkaline electrolyzer are both relatively high, getting rid of the limitation of the porous structure of the traditional composite diaphragm on the airtightness of the diaphragm.

[0041] (4) The present invention not only realizes the improvement of airtightness, but also shows excellent electrochemical performance. When the thicknesses are similar, the electrochemical performance of the present invention is comparable to that of commercial products of organic-inorganic composite diaphragms, and as the thickness of the coating decreases, the performance of the solid electrolyte membrane is better. Compared with the anion exchange membrane without a coating, the electrochemical performance loss caused by the coating is also within an acceptable range.

[0042] (5) The solid electrolyte membrane prepared by the present invention can be adapted to an alkaline electrolyzer with a higher pressure due to its better airtightness, so as to further improve the electrolysis rate.

[0043] (6) The "sandwich" composite structure proposed by the present invention is simple, easy to operate, and easy to industrialize, and can be used for alkaline electrolytic water hydrogen production and anion exchange membrane electrolytic water hydrogen production.

[0044] (7) The present invention can be used for strengthening the mechanical properties of commercial anion exchange membrane products, and only needs to hot-press the commercial anion exchange membrane and the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flowchart of the preparation method of the present invention;

[0046] Figure 2 is a structural schematic diagram of the present invention (in the figure: 1 - anion exchange membrane; 2 - coating);

[0047] Figure 3This is the pore size distribution diagram of the coating 2 provided on both sides of the anion exchange membrane in the present invention. Detailed implementation manners

[0048] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0049] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following embodiments are all commercially available.

[0050] A solid electrolyte membrane for alkaline electrolytic water hydrogen production, the structural schematic diagram is as Figure 2 shown, including an anion exchange membrane 1 and coatings 2 provided on both sides of the anion exchange membrane, forming a "sandwich" composite structure of "coating - anion exchange membrane - coating", and the coating includes a mixture of a thermoplastic resin and hydrophilic inorganic nanoparticles.

[0051] Its preparation method is as Figure 1 shown, and includes the following steps:

[0052] S1: Prepare coating slurry and anion exchange membrane slurry respectively;

[0053] S2: Coat the coating slurry on a transfer substrate, and obtain a transfer substrate / coating after drying;

[0054] S3: Coat the coating slurry and the anion exchange membrane slurry on the transfer substrate in sequence, and obtain a transfer substrate / coating / anion exchange membrane after drying;

[0055] S4: Thermal transfer.

[0056] Example 1

[0057] A solid electrolyte membrane for alkaline electrolytic water hydrogen production is prepared as follows. At 80 °C, 20 g of polysulfone (PSU) is placed in 85 g of N-methyl-2-pyrrolidone (NMP) and mechanically stirred until the PSU is completely dissolved. Then, 85 g of zirconia with a particle size of 40 nm is added in batches, and mechanically stirred and dispersed at 2000 rpm for 6 hours. After vacuum degassing, a coating slurry is obtained. Using a 50-μm doctor blade, the coating slurry is scraped onto a polytetrafluoroethylene membrane (transfer substrate) and placed in an oven at 80 °C for 3 hours. At 80 °C, 25 g of quaternized polysulfone (QAPSU) is placed in 75 g of NMP and mechanically stirred until the QAPSU is completely dissolved to obtain an anion exchange membrane slurry. Using a 75-μm doctor blade, the anion exchange membrane slurry is scraped onto the coating and placed in an oven at 80 °C for 3 hours. The coating with the anion exchange membrane and the coating without the anion exchange membrane are placed in a hot press and hot pressed at 150 °C and 1 MPa for 10 minutes. After cooling to room temperature, the polytetrafluoroethylene membranes on both sides are removed, and the solid electrolyte membrane for alkaline electrolytic water hydrogen production can be obtained.

[0058] Example 2

[0059] A solid electrolyte membrane for alkaline electrolytic water hydrogen production is prepared as follows. At 80 °C, 20 g of polysulfone (PSU) is placed in 85 g of NMP and mechanically stirred until the PSU is completely dissolved. Then, 85 g of zirconia with a particle size of 40 nm is added in batches, and mechanically stirred and dispersed at 2000 rpm for 6 hours. After vacuum degassing, a coating slurry is obtained. Using a 100-μm doctor blade, the coating slurry is scraped onto a polytetrafluoroethylene membrane and placed in an oven at 80 °C for 3 hours. At 80 °C, 25 g of quaternized polysulfone (QAPSU) is placed in 75 g of NMP and mechanically stirred until the QAPSU is completely dissolved to obtain an anion exchange membrane slurry. Using a 75-μm doctor blade, the anion exchange membrane slurry is scraped onto the coating and placed in an oven at 80 °C for 3 hours. The coating with the anion exchange membrane and the coating without the anion exchange membrane are placed in a hot press and hot pressed at 150 °C and 1 MPa for 10 minutes. After cooling to room temperature, the polytetrafluoroethylene membranes on both sides are removed, and the solid electrolyte membrane for alkaline electrolytic water hydrogen production can be obtained.

[0060] Example 3

[0061] A solid electrolyte membrane for alkaline electrolytic water hydrogen production is prepared as follows. At 80 °C, 20 g of polysulfone (PSU) is placed in 85 g of NMP and mechanically stirred until the PSU is completely dissolved. Then, 85 g of zirconia with a particle size of 40 nm is added in batches, and mechanically stirred and dispersed at 2000 rpm for 6 hours. After vacuum degassing, a coating slurry is obtained. Using a 50-μm doctor blade, the coating slurry is scrape-coated onto a polytetrafluoroethylene membrane and placed in an oven at 80 °C for 3 hours. At 80 °C, 25 g of quaternized polyphenylene oxide (QAPPO) is placed in 75 g of NMP and mechanically stirred until the QAPSU is completely dissolved to obtain an anion exchange membrane slurry. Using a 75-μm doctor blade, the anion exchange membrane slurry is scrape-coated onto the coating. And it is placed in an oven at 80 °C for 3 hours. The coating with the anion exchange membrane and the coating without the anion exchange membrane are placed in a hot press and hot-pressed at 150 °C and 1 MPa for 10 minutes. After cooling to room temperature, the polytetrafluoroethylene membranes on both sides are removed, and the solid electrolyte membrane for alkaline electrolytic water hydrogen production can be obtained.

[0062] Example 4

[0063] A solid electrolyte membrane for alkaline electrolytic water hydrogen production is prepared as follows. At 80 °C, 20 g of polysulfone (PSU) is placed in 85 g of NMP and mechanically stirred until the PSU is completely dissolved. Then, 85 g of zirconia with a particle size of 40 nm is added in batches, and mechanically stirred and dispersed at 2000 rpm for 6 hours. After vacuum degassing, a coating slurry is obtained. Using a 100-μm doctor blade, the coating slurry is scrape-coated onto a polytetrafluoroethylene membrane and placed in an oven at 80 °C for 3 hours. At 80 °C, 25 g of quaternized polyphenylene oxide (QAPPO) is placed in 75 g of NMP and mechanically stirred until the QAPSU is completely dissolved to obtain an anion exchange membrane slurry. Using a 75-μm doctor blade, the anion exchange membrane slurry is scrape-coated onto the coating. And it is placed in an oven at 80 °C for 3 hours. The coating with the anion exchange membrane and the coating without the anion exchange membrane are placed in a hot press and hot-pressed at 150 °C and 1 MPa for 10 minutes. After cooling to room temperature, the polytetrafluoroethylene membranes on both sides are removed, and the solid electrolyte membrane for alkaline electrolytic water hydrogen production can be obtained.

[0064] Comparative Example 1

[0065] A quaternized polysulfone anion exchange membrane is prepared in the same process as in Example 1, but no coating is applied on both sides.

[0066] Comparative Example 2

[0067] A quaternized polyphenylene oxide anion exchange membrane is prepared in the same process as in Example 3, but no coating is applied on both sides.

[0068] Comparative Example 3

[0069] An organic-inorganic composite diaphragm commercial product, model Zirfon PERL UTP 220.

[0070] Table 1 Pore structure of the coating

[0071] Example 1 Example 2 Doctor blade specification / μm 50 100 Coating 2 thickness / μm 33 82 Average pore diameter / nm 49.3 49.9 Most probable pore diameter / nm 49 50.1 Bubble point pore diameter / nm 75.3 72.9 Minimum pore diameter / nm 46.9 47 Bubble point pressure / bar 8.41 8.69

[0072] The pore structure of coating 2 in the solid electrolyte membranes for alkaline water electrolysis hydrogen production prepared in Example 1 and Example 2 was tested under the following conditions: the test method was the bubble pressure method, the temperature was 20 °C, the wetting liquid was absolute ethanol, and nitrogen displacement was used. The results are shown in Table 1 and Figure 3 As shown, in the present invention, the coating 2 provided on both sides of the anion exchange membrane is a porous structure. In Example 1, when a 50 μm doctor blade was used for coating preparation of coating 2, its average pore diameter was about 49.3 nm. In Example 2, when a 100 μm doctor blade was used for coating preparation of coating 2, its average pore diameter was about 49.9 nm.

[0073] Table 2 Performance parameters of the solid electrolyte membrane

[0074]

[0075] Table 3 Performance parameters of the solid electrolyte membrane after being rubbed 1000 times with 500 g steel wool

[0076]

[0077] Table 2 shows the water absorption swelling rate and tensile strength of Comparative Examples 1-2 and Examples 1-4, indicating that the coating in the "sandwich" composite structure of "coating - anion exchange membrane - coating" successfully limits the swelling phenomenon of the anion exchange membrane and improves the tensile strength.

[0078] Table 3 shows the performance parameters of Comparative Examples 1-2 and Examples 1-4 after the steel wool friction test. Compared with the anion exchange membrane without coating, the water absorption swelling rate and tensile strength of Examples 1-4 show almost no obvious change, indicating that the coating plays a protective role on the anion exchange membrane, proving that the solid electrolyte membrane for alkaline water electrolysis hydrogen production proposed by the present invention has excellent stability.

[0079] Table 4 Air tightness of Comparative Example 3 and Examples 1-4 in an alkaline electrolyzer at 500 mA / cm 2 under

[0080] Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Hydrogen purity / % 99.935 99.992 99.993 99.992 99.992 Oxygen purity / % 99.880 99.915 99.921 99.917 99.917

[0081] Table 4 shows the air tightness of Comparative Example 3 and Examples 1-4 in an alkaline electrolyzer at 500 mA / cm 2Regarding the airtightness below, it can be seen that the purity of hydrogen and oxygen produced by the alkaline water electrolyzers equipped with Examples 1-4 is much higher than that of the alkaline water electrolyzer equipped with Comparative Example 3. This is exactly the role played by the anion exchange membrane in the solid electrolyte membrane proposed by the present invention, getting rid of the limitation of the porous structure of the traditional composite diaphragm on the airtightness of the diaphragm.

[0082] Table 5 Electrochemical Performance of Comparative Examples 1-2 and Examples 1-4 in Anion Exchange Membrane Electrolyzers

[0083]

[0084] Table 6 Electrochemical Performance of Comparative Examples 1-2 and Examples 1-4 in Alkaline Water Electrolyzers

[0085]

[0086] Table 5 shows the electrochemical performance of Comparative Examples 1-2 and Examples 1-4 in anion exchange membrane electrolyzers. The upper cell test conditions are as follows: the electrolyzer temperature is 90 °C, the anode and cathode are both nickel foam, the electrolyte is 1 M KOH solution, the flow rate is 500 ml / min, and the liquid is fed from both sides. It can be seen that the "sandwich" composite structure proposed by the present invention significantly increases the thickness of the solid electrolyte membrane. Coupled with the fact that the coating itself has a certain resistance to OH - conduction, the electrochemical performance of the examples all shows a small decrease, and with the increase of the coating thickness, the performance decline intensifies. However, considering the importance of diaphragm stability for safe hydrogen production, the performance loss caused by the coating is within an acceptable range.

[0087] Table 6 shows the electrochemical performance of Comparative Example 3 and Examples 1-4 in alkaline water electrolyzers. The upper cell test conditions are as follows: the electrolyzer temperature is 90 °C, the anode and cathode are both ordinary nickel meshes, the electrolyte is 30 wt% KOH solution, the flow rate is 500 ml / min, the liquid is fed from both sides, and it is carried out under normal pressure. It can be seen that the electrochemical performance of Comparative Example 3 and Examples 2 and 4 with similar thicknesses is almost the same, and with the decrease of the coating thickness, the performance of the solid electrolyte membrane is better. The solid electrolyte membrane proposed by the present invention not only improves the airtightness compared with the traditional organic-inorganic composite diaphragm, but also shows excellent electrochemical performance.

[0088] In summary, the present invention prepares a solid electrolyte membrane with a "sandwich" composite structure of "coating - anion exchange membrane - coating" by coating a coating composed of a thermoplastic resin and hydrophilic inorganic nanoparticles on both sides of the anion exchange membrane, which can effectively prevent the swelling deformation and damage of the anion exchange membrane, improve the mechanical properties and stability of the anion exchange membrane, and at the same time solve the problem of limited airtightness of the composite diaphragm.

[0089] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A solid electrolyte membrane for producing hydrogen by alkaline water electrolysis, characterized in that: The invention comprises an anion exchange membrane and a coating arranged on both sides of the anion exchange membrane, forming a "coating-anion exchange membrane-coating" "sandwich" composite structure, wherein the coating comprises a mixture of a thermoplastic resin and hydrophilic inorganic nanoparticles.

2. A solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The thickness of the anion exchange membrane is 10-200 μm, and the thickness of the coatings on both sides is 0.5-3 times the thickness of the anion exchange membrane.

3. The solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The anion exchange membrane is prepared from anion exchange membrane resin, and the anion exchange membrane resin includes one or more of quaternized polysulfone, quaternized polyphenylene ether, quaternized polybenzimidazole, quaternized polystyrene, alkylated polybenzimidazole, polyaryl piperidine, and polyaryl quinine.

4. The solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: The thermoplastic resin includes one or more of polysulfone, polyethersulfone, polyphenylene sulfide, polypropylene, polyetheretherketone, polyimide, and polyetherimide; The hydrophilic inorganic nanoparticles have a particle size of 30 to 100 nm and include one or more of zirconium dioxide, cerium dioxide, titanium dioxide, and barium sulfate.

5. A method for preparing a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1: preparing coating slurry and anion exchange membrane slurry respectively; S2: coating the coating slurry on the transfer substrate, and drying to obtain the transfer substrate / coating; S3: coating the coating slurry and the anion exchange membrane slurry on the transfer substrate in sequence, and drying to obtain the transfer substrate / coating / anion exchange membrane; S4: Thermal transfer.

6. The method for preparing a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 5, characterized in that: In step S1, The preparation process of the coating slurry comprises the following steps: dissolving a thermoplastic resin and hydrophilic inorganic nanoparticles in an organic solvent, and mixing them uniformly to obtain the coating slurry; the mass ratio of the thermoplastic resin to the organic solvent is 1:9-1:1, and the mass ratio of the thermoplastic resin to the hydrophilic inorganic nanoparticles is 1:10-10:3; The preparation process of the anion exchange membrane slurry comprises the following steps: dissolving anion exchange membrane resin in an organic solvent to obtain the anion exchange membrane slurry after dissolution; the content of the anion exchange membrane resin in the organic solvent is 10-50wt%.

7. The method for preparing a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 6, characterized in that: In step S1, the organic solvent in the coating slurry and the anion exchange membrane slurry includes one or more of N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, formamide, and N,N-dimethylacetamide.

8. The method for preparing a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 5, characterized in that: In steps S2 and S3, the transfer substrate comprises any one of a polypropylene film, a polyethylene film, and a polytetrafluoroethylene film; the drying temperature is 50-90° C., and the drying time is more than 3 hours.

9. The method for preparing a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis according to claim 5, characterized in that: The specific process of thermal transfer in step S4 is: hot pressing the transfer substrate / coating and the printing substrate / coating / anion exchange membrane together, and after cooling to room temperature, removing the transfer substrates on both sides to obtain the solid electrolyte membrane for hydrogen production by alkaline water electrolysis; the hot pressing temperature is 100-200°C, the pressure is 0.1-10MPa, and the time is 1-20 minutes.

10. Use of a solid electrolyte membrane for producing hydrogen by alkaline water electrolysis as claimed in any one of claims 1 to 4 in producing hydrogen by alkaline water electrolysis.

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