Water electrolysis hydrogen production diaphragm, preparation method thereof and water electrolysis hydrogen production device

Abstract

The invention relates to the technical field of hydrogen production, and provides a water electrolysis hydrogen production diaphragm, a preparation method thereof and a water electrolysis hydrogen production device. The water electrolysis hydrogen production diaphragm comprises a base material layer and a porous hydrophilic layer. Wherein the porous hydrophilic layer is arranged on the surface of at least one side of the base material layer, a plurality of modified inorganic particles are dispersed in the porous hydrophilic layer, and the modified inorganic particles comprise inorganic particles and modified materials coating at least part of the surfaces of the inorganic particles. The modified material contains a siloxane main chain, a polyether chain segment and an alkyl chain segment, so that the compatibility between inorganic particles and an organic polymer is improved, and high ionic conductivity, excellent gas barrier property, good mechanical strength and long-term operation stability of the diaphragm are realized.

Description

Technical Field

[0001] This application relates to the field of hydrogen production technology, and in particular to the electrolysis of water to produce hydrogen membranes, their preparation methods, and the electrolysis of water to produce hydrogen apparatus. Background Technology

[0002] Alkaline water electrolysis for hydrogen production offers advantages such as relatively low cost and ease of scalability. In an alkaline water electrolysis system, the diaphragm is a core component. Its main function is to prevent hydrogen and oxygen from mixing within the electrolyzer, thus avoiding the formation of explosive gases, while simultaneously allowing efficient conduction of hydroxide ions to complete the circuit and ensure the continuous electrolysis reaction. Therefore, the performance of the diaphragm directly affects the electrolyzer's operating efficiency, gas purity, safety, and service life.

[0003] Currently, membrane materials mainly include organic polymer membranes, such as polysulfone (PSF), polyetheretherketone (PEEK), and polyphenylene sulfide (PPS). Organic polymer membranes generally possess superior mechanical strength and chemical stability. However, they often suffer from poor hydrophilicity and low ionic conductivity. Furthermore, long-term operation in alkaline solutions may lead to swelling or microstructural changes, affecting the efficiency of hydrogen production through water electrolysis. Although inorganic fillers can be added to the aforementioned organic polymer membranes to improve their hydrophilicity and ionic conductivity, the compatibility between inorganic fillers and organic polymers is poor. Inorganic fillers are prone to agglomeration, resulting in uneven distribution of the inorganic fillers within the membrane and the formation of interfacial defects. This not only affects the mechanical properties of the membrane but may also worsen its gas barrier properties. Summary of the Invention

[0004] Therefore, it is necessary to provide a water electrolysis hydrogen production membrane, its preparation method, and a water electrolysis hydrogen production device that can take into account high ionic conductivity, low gas permeability, excellent mechanical strength, and long-term chemical stability.

[0005] In a first aspect, this application provides a membrane for hydrogen production through water electrolysis, comprising:

[0006] Substrate layer;

[0007] A porous hydrophilic layer is disposed on at least one surface of a substrate layer. Multiple modified inorganic particles are dispersed within the porous hydrophilic layer. The modified inorganic particles include inorganic particles and a modifying material coating at least a portion of the surface of the inorganic particles. The structural formula of the modifying material is as follows:

[0008]

[0009] Among them, R 11 R 12 and R 13Each is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group; the number average molecular weight of the modified material is 200-2000.

[0010] In some embodiments, the modified material R2 contains at least one of polyoxyethylene segments and polyoxypropylene segments.

[0011] In some embodiments, the porous hydrophilic layer satisfies at least one of the following conditions:

[0012] (1) The porous hydrophilic layer contains 0.1% to 1% by mass of the modified material, which is inorganic particles;

[0013] (2) The porous hydrophilic layer contains inorganic particles accounting for 70% to 90% of the total mass.

[0014] In some embodiments, the porous hydrophilic layer also satisfies at least one of the following conditions:

[0015] (1) The porosity of the porous hydrophilic layer is 50%~65%, and the average pore size is 80nm~120nm;

[0016] (2) The thickness of the porous hydrophilic layer is 100μm~150μm.

[0017] In some embodiments, the water electrolysis hydrogen production membrane satisfies at least one of the following conditions:

[0018] (1) The material of the porous hydrophilic layer includes at least one of polysulfone resin, sulfonated polysulfone, polyethersulfone, polyetheretherketone resin and polyphenylene sulfide resin;

[0019] (2) The inorganic particles include at least one of zirconium dioxide, titanium dioxide and silicon dioxide;

[0020] (3) The particle size D90 of the inorganic particles is less than 1 μm;

[0021] (4) The substrate layer includes at least one of polyphenylene sulfide mesh, polypropylene mesh and nylon mesh.

[0022] Secondly, this application provides a method for preparing a water electrolysis hydrogen production membrane, the method comprising:

[0023] A mixture comprising inorganic particles and a modifying material is prepared, such that the modifying material coats at least a portion of the surface of the inorganic particles to form modified inorganic particles; the structural formula of the modifying material is:

[0024]

[0025] Among them, R 11 R 12 and R 13Each is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group; the number average molecular weight of the modified material is 200-2000;

[0026] A resin material and a pore-forming agent are added to a mixture to form a casting solution; the casting solution is then coated onto at least one side of a substrate layer to form a wet film layer. After removing the pore-forming agent from the wet film layer, a porous hydrophilic layer containing multiple modified inorganic particles is formed on the surface of the substrate layer.

[0027] In some embodiments, the preparation method satisfies at least one of the following conditions:

[0028] (1) The mass percentage of inorganic particles in the mixture is 70% to 90%, and the mass of the modified material is 0.1% to 1% of the mass of the inorganic particles;

[0029] (2) The mass ratio of the resin material to the inorganic particles is 1:(5~8);

[0030] (3) The mass of the pore-forming agent is 1% to 10% of the mass of the resin material.

[0031] In some embodiments, the preparation method also satisfies at least one of the following conditions:

[0032] (1) A mixture is formed by at least one of stirring, ball milling and ultrasonication;

[0033] (2) Before forming the wet film layer, the preparation method also includes: degassing the casting solution.

[0034] In some implementations, a coagulation bath phase transformation method is used to remove the pore-forming agent.

[0035] The solvent used for the phase transition in the coagulation bath includes at least one of water, ethanol, and methanol; the temperature for the phase transition in the coagulation bath is 5℃~80℃.

[0036] Thirdly, this application also provides a water electrolysis hydrogen production device, which includes a water electrolysis hydrogen production membrane prepared by the method described in the first aspect or the second aspect.

[0037] Compared with traditional technologies, this application has at least the following beneficial effects:

[0038] This application employs modified materials to modify inorganic particles. The siloxane backbone contained in the modified material has strong physical / chemical interactions with the inorganic particles, and the polyether segments have good compatibility with the porous hydrophilic layer material and possess a certain degree of hydrophilicity. This allows for the formation of interconnected hydrophilic regions within the membrane, effectively reducing the interfacial energy between the inorganic particles and the porous hydrophilic layer material and preventing the aggregation of inorganic particles. Simultaneously, the modified material also possesses certain surface activity, which can improve the leveling properties during the film formation process, thereby forming a porous hydrophilic layer with a smooth surface, uniform dispersion, and good stability. This layer has advantages such as fewer microscopic defects, good density, and high mechanical strength.

[0039] Furthermore, the polyether segments in the modified material of this application can impart appropriate hydrophilicity to the diaphragm, thereby facilitating electrolyte wetting and hydroxide ion transport, effectively improving the ionic conductivity of the diaphragm, and effectively reducing the energy consumption of the electrolyzer. Moreover, the modified material of this application exhibits excellent chemical and thermal stability, enabling it to remain stably present in the diaphragm and ensuring its long-term operational stability. Attached Figure Description

[0040] Figure 1 This is a SEM image of the water electrolysis hydrogen production membrane prepared in Example 1 of this application;

[0041] Figure 2 SEM image of the water electrolysis hydrogen production membrane prepared in Comparative Example 1 of this application;

[0042] Figure 3 This is a comparison graph of the current density of Embodiment 1 and Comparative Example 1 under different electrolysis voltages. Detailed Implementation

[0043] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0044] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0045] In this application, the terms "first aspect," "second aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first aspect," "second aspect," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0046] The term "alkyl" refers to a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-C6 alkyl," refer to alkyl groups containing 1 to 6 carbon atoms, and each time it appears, it can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, or C6 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -C H(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl -1-Butyl(-CH2CH2CH(CH3)2), 2-Methyl-1-Butyl(-CH2CH(CH3)CH2CH3), 1-Hexyl(-CH2CH2CH2CH2CH2CH3), 2-Hexyl(-CH(CH3)CH2CH2CH2CH3), 3-Hexyl(-CH(CH2CH3)(CH2CH2CH3)), 2-Methyl-2-pentyl(-C(CH3)2CH2CH2CH3), 3-Methyl-2-pentyl( -CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2) and 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3).

[0047] The term "alkoxy" refers to a group having an -O-alkyl group, i.e., an alkyl group as defined above connected to the parent nucleus via an oxygen atom. Phrases containing this term, such as "C1-C6 alkoxy," refer to alkyl moieties containing 1-9 carbon atoms, and each occurrence can be independently C1 alkoxy, C4 alkoxy, C5 alkoxy, or C6 alkoxy. Suitable examples include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-OC(CH3)3 or -OtBu).

[0048] In traditional technologies, compatibilizers or surfactants can be added to improve the compatibility between inorganic particles and organic polymers, preventing the aggregation of inorganic particles and improving membrane performance. For example, silane coupling agents (KH-550, γ-aminopropyltriethoxysilane) can be used. However, traditional compatibilizers or surfactants lack stability under strong alkaline, high-temperature, and electric field environments during water electrolysis, and are prone to decomposition or migration, leading to a gradual decline in membrane performance.

[0049] Based on this, the first aspect of this application provides a water electrolysis hydrogen production membrane, comprising a substrate layer and a porous hydrophilic layer. The porous hydrophilic layer is disposed on at least one surface of the substrate layer, and a plurality of modified inorganic particles are dispersed in the porous hydrophilic layer. The modified inorganic particles include inorganic particles and a modifying material coating at least a portion of the surface of the inorganic particles. The modified material has the following structural formula:

[0050]

[0051] Among them, R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group, and the number average molecular weight of the modified material is 200-2000.

[0052] This application uses modified materials to modify inorganic particles. The siloxane backbone contained in the modified materials has strong physical / chemical interactions with the inorganic particles, and the polyether segments have good compatibility with the porous hydrophilic layer material and have a certain degree of hydrophilicity. It can form interconnected hydrophilic regions in the membrane, effectively reducing the interfacial energy between the inorganic particles and the porous hydrophilic layer material and preventing the inorganic particles from agglomerating. At the same time, the modified materials also have a certain degree of surface activity, which can improve the leveling during the film formation process, thereby forming a porous hydrophilic layer with a smooth surface, uniform dispersion and good stability. It has the advantages of few microscopic defects, good density and high mechanical strength.

[0053] Furthermore, the polyether segments in the modified material of this application can impart appropriate hydrophilicity to the diaphragm, thereby facilitating electrolyte wetting and hydroxide ion transport, effectively improving the ionic conductivity of the diaphragm, and effectively reducing the energy consumption of the electrolyzer. Moreover, the modified material of this application exhibits excellent chemical and thermal stability, enabling it to remain stably present in the diaphragm and ensuring its long-term operational stability.

[0054] The number-average molecular weight of the modified material is 200-2000, for example, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, or 2000. This application selects the molecular weight of the modified material as described above. The modified material has a fast migration speed and can quickly adsorb onto the interface of inorganic particles, reducing surface tension. Furthermore, the modified material contains a high proportion of hydrophilic polyether segments, thereby further improving the material's hydrophilicity. If the molecular weight of the modified material is relatively high, the polymer chains in the modified material may become severely entangled, greatly increasing the material viscosity and resulting in poor dispersibility in the slurry, making film formation difficult. Moreover, a relatively large molecular weight of the modified material may also clog the nano- or micro-sized pores of the membrane, affecting the membrane performance.

[0055] In some embodiments, the modified material R2 contains at least one of polyoxyethylene segments and polyoxypropylene segments. Optionally, it contains polyoxyethylene segments. In this application, R2 contains polyoxyethylene segments, which can synergistically cooperate with the ether oxygen bonds (-Si-O-Si-) in the segments to generate strong interactions with KOH or NaOH in the alkaline electrolyte, thereby rapidly adsorbing the electrolyte, allowing the electrolyte to fully wet the membrane, and quickly forming ion transport channels.

[0056] In some embodiments, the mass ratio of the modified material in the porous hydrophilic layer to inorganic particles is 0.1% to 1%, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%.

[0057] In some embodiments, the porous hydrophilic layer contains inorganic particles in a mass ratio of 70% to 90%, for example, 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, or 90%.

[0058] This application controls the content of modified materials to further improve the ionic conductivity, airtightness, and operational stability of the diaphragm. If the content of modified materials is relatively high, the modified materials may act as a second phase, severely hindering the formation of a continuous phase in the diaphragm matrix material during film formation, leading to problems such as phase separation and aggregation, resulting in irregular macropores or defects in the diaphragm.

[0059] In some embodiments, the porosity of the porous hydrophilic layer is 50% to 65%, for example, it can be 50%, 53%, 56%, 59%, 62%, or 65%. The average pore size is 80 nm to 120 nm, for example, it can be 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, or 120 nm. The thickness of the porous hydrophilic layer is 100 μm to 150 μm, for example, it can be 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, or 150 μm.

[0060] In some embodiments, the material of the porous hydrophilic layer includes at least one selected from polysulfone resin, sulfonated polysulfone, polyethersulfone, polyetheretherketone resin, and polyphenylene sulfide resin. Optionally, the polysulfone resin includes at least one selected from sulfonated polysulfone, polyethersulfone, poly(arylene ether sulfone), tertiary amination polysulfone, and chloromethyl polysulfone.

[0061] In some embodiments, the inorganic particles are made of at least one of zirconium dioxide, titanium dioxide, and silicon dioxide. Zirconium dioxide may be selected as the material.

[0062] In some embodiments, the particle size D90 of the inorganic particles is less than 1 μm, for example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm. Here, D90 of 1 μm means that in the particle size distribution curve, 90% of the particles are smaller than 1 μm.

[0063] In some embodiments, the substrate layer includes at least one layer of polyphenylene sulfide mesh, polypropylene mesh, and nylon mesh.

[0064] The second aspect of this application provides a method for preparing a water electrolysis hydrogen production membrane, the method comprising:

[0065] A mixture comprising inorganic particles and a modifying material is prepared, such that the modifying material coats at least a portion of the surface of the inorganic particles to form modified inorganic particles; the structural formula of the modifying material is:

[0066]

[0067] Among them, R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group, and the number average molecular weight of the modified material is 200-2000;

[0068] A resin material and a pore-forming agent are added to a mixture to form a casting solution; the casting solution is then coated onto at least one side of a substrate layer to form a wet film layer. After removing the pore-forming agent from the wet film layer, a porous hydrophilic layer containing multiple modified inorganic particles is formed on the surface of the substrate layer.

[0069] In some embodiments, the modified material can be prepared by hydrosilylation of a polymer material containing active silane-hydrogen bonds and a polyether material. For example, the preparation method of the modified material includes: using silicone oil containing active silane-hydrogen bonds (Si-H) and polyether with allyl groups at the end as the main raw materials, an addition reaction is carried out under the catalysis of a platinum catalyst at a certain temperature (e.g., 80℃~110℃) and under an inert atmosphere, so that the Si-H bonds combine with the carbon-carbon double bonds at the end of the polyether to form stable Si-C bond connections, thereby obtaining the target product. After neutralization, filtration and other post-treatment steps, the product can be purified to obtain the product.

[0070] In some embodiments, the inorganic particles in the mixture constitute 70% to 90% by mass, for example, 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, or 90%. The modified material constitutes 0.1% to 1% by mass, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0%.

[0071] Optionally, the solvent in the mixture includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide.

[0072] In some embodiments, the mass ratio of the resin material to the inorganic particles is 1:(5~8), for example, it can be 1:5.0, 1:5.3, 1:5.6, 1:5.9, 1:6.2, 1:6.5, 1:6.8, 1:7.1, 1:7.4, 1:7.7 or 1:8.0.

[0073] The mass of the pore-forming agent is 1% to 10% of the mass of the resin material, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0074] Optionally, the pore-forming agent includes at least one of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA).

[0075] In some embodiments, the mixture is formed by at least one of stirring, ball milling, and ultrasonication.

[0076] In some embodiments, when adding resin material to the mixture, the resin material is completely dissolved by heating and stirring.

[0077] In some embodiments, the preparation method further includes degassing the casting solution before forming the wet film layer.

[0078] In some embodiments, a coagulation bath phase inversion method is used to remove the porogen. Optionally, the wet film layer is pre-evaporated before removing the porogen to remove the solvent from the wet film layer.

[0079] Optionally, the solvent used for the phase inversion in the coagulation bath includes at least one of water, ethanol, and methanol.

[0080] Optionally, the phase transformation temperature of the solidification bath is 5℃~80℃, for example, it can be 5℃, 10℃, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃ or 80℃.

[0081] Exemplary, a method for preparing the above-mentioned water electrolysis hydrogen production membrane is provided, comprising the following steps:

[0082] The modified material, inorganic particles, and solvent are mixed to form a mixture. The inorganic particles account for 70% to 90% of the mass of the mixture, and the modified material accounts for 0.1% to 1% of the mass of the inorganic particles.

[0083] Add resin material and pore-forming agent to the mixture, heat and stir until the resin material is completely dissolved to obtain casting solution, and then degas the casting solution.

[0084] The degassed casting solution is coated onto at least one side of the substrate layer to form a wet film layer. After the wet film layer is pre-evaporated, a coagulation bath phase transformation is performed to remove the pore-forming agent. After curing, an electrolytic water hydrogen production membrane is prepared.

[0085] The third aspect of this application also provides an electrolytic water hydrogen production device, which includes an electrolytic water hydrogen production membrane prepared by the method of the first aspect or the method of the second aspect.

[0086] In some embodiments, the water electrolysis hydrogen production device includes a cathode, an anode, the water electrolysis hydrogen production diaphragm, and an electrolytic cell filled with electrolyte. The water electrolysis hydrogen production diaphragm is disposed in the electrolytic cell, dividing the electrolytic cell into a cathode side and an anode side. The cathode is disposed on the cathode side, and the anode is disposed on the anode side.

[0087] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0088] The polysulfone resin used in the following examples was purchased from Solvay, and its brand name was Udels P-3500.

[0089] Example 1

[0090] 200g of zirconium dioxide particles and 0.6g of the modified material were dissolved in 200mL of N-methylpyrrolidone and mixed at 10000rpm in a shear emulsifier for 10min to obtain a mixture. The zirconium dioxide particles had a D90 of 1μm; in the structural formula of the modified material, R1 and R3 were methyl groups, R2 was a polyoxyethylene segment, and the number-average molecular weight of the modified material was approximately 1000.

[0091] Add 50g of polysulfone resin and 2g of pore-forming agent (polyvinylpyrrolidone) to the above mixture, stir at 60°C until completely dissolved to obtain a homogeneous and stable casting solution, and then degas the casting solution for 24 hours.

[0092] The deaerated casting solution was coated onto both sides of the polyphenylene sulfide (PPS) mesh fabric and pre-evaporated at 25°C for 30 seconds. Then, it was immersed in water at 25°C for phase inversion. After complete curing, a porous hydrophilic layer with a thickness of 150 μm was formed on both sides of the PPS mesh fabric, with a porosity of 62% and an average pore diameter of 90 nm. This yielded the desired film. Figure 1 The membrane shown is used for hydrogen production via water electrolysis.

[0093] Example 2

[0094] The water electrolysis hydrogen production membrane was prepared according to the method of Example 1, except that the amount of modified material added was 0.2g.

[0095] Example 3

[0096] The water electrolysis hydrogen production membrane was prepared according to the method of Example 1, except that the amount of modified material added was 1g.

[0097] Example 4

[0098] The water electrolysis hydrogen production membrane was prepared according to the method of Example 1, except that the number average molecular weight of the modified material was approximately 2500.

[0099] Comparative Example 1

[0100] The water electrolysis hydrogen production membrane was prepared according to the method in Example 1, except that no modifying material was added. The SEM image of the prepared water electrolysis hydrogen production membrane is shown below. Figure 2 As shown.

[0101] Comparative Example 2

[0102] The water electrolysis hydrogen production membrane was prepared according to the method of Example 1, except that the modified material was replaced with an equal mass of silane coupling agent (KH-550, γ-aminopropyltriethoxysilane).

[0103] The tensile strength of the water electrolysis hydrogen production membranes prepared in the above embodiments and comparative examples was tested according to GB-T 1040.3-2006, and the test results are shown in Table 1.

[0104] The electrolytic water hydrogen production membranes prepared in the above embodiments and comparative examples are assembled to form an electrolytic water hydrogen production device. The electrolyte is a 30% KOH solution, the cathode is Raney nickel, and the anode is a nickel mesh.

[0105] The sheet resistance, current at 1.8V, bubble point, and resistance retention rate of the diaphragm were tested at an electrolyte temperature of 80℃. The test results are shown in Table 1, where the current density of Example 1 and Comparative Example 1 at different electrolysis voltages is shown in Table 1. Figure 3 As shown. Among them, the surface resistance test is based on patent CN 104678173 B. The bubble point test is based on standard GB / T 32361-2015.

[0106] Table 1

[0107]

[0108] As can be seen from the table above:

[0109] In this application, modified materials are introduced into the membrane, forming more efficient ion conduction channels and a denser barrier structure, resulting in higher ion conductivity and better gas barrier properties. Furthermore, the polysiloxane backbone and polyether segments of the modified material synergistically improve the mechanical strength of the membrane, and the balance between hydrophilic and hydrophobic properties leads to slower membrane degradation and better operational stability.

[0110] Compared with Example 4, Example 1 shows that this application controls the molecular weight of the modified material, thereby improving the balance between the hydrophilicity and hydrophobicity of the membrane, effectively inhibiting membrane swelling, and maintaining its dimensional stability and mechanical integrity. If the molecular weight of the modified material is relatively large, it leads to severe polymer chain entanglement, a significant increase in viscosity, difficulty in uniform dispersion in the membrane-forming solution, and easy formation of visible micelles. Simultaneously, excessively large molecular chains may physically block the carefully designed nano- or micro-sized pores of the membrane.

[0111] Compared with Comparative Example 1, Example 1 combines Figure 1 and Figure 2 The diaphragm of this application has a dense surface structure with no obvious defects; while the surface of Comparative Example 1 has obvious pits. Further... Figure 3It can also be seen that, under the same electrolysis voltage, the current density of Example 1 is significantly better than that of Comparative Example 1. Therefore, by introducing modified materials into the diaphragm, this application not only reduces surface defects, but also ensures good diaphragm density and high mechanical strength.

[0112] Compared with Comparative Example 2, it can be seen that although introducing a silane coupling agent into the diaphragm can slightly improve the diaphragm performance, the silane coupling agent is prone to decomposition and migration during electrolysis, which affects the stability of the diaphragm. Furthermore, the silane coupling agent does not contain hydrophilic groups, which will affect the hydrophilicity of zirconium oxide, thus negatively impacting the surface resistance of the diaphragm.

[0113] In summary, this application introduces specific modified materials into the diaphragm to improve the compatibility between inorganic particles and organic polymers. Furthermore, by utilizing the synergistic effect of polysiloxane backbone, polyether segments, and alkyl segments in the modified materials, the diaphragm achieves high ionic conductivity, excellent gas barrier properties, good mechanical strength, and long-term operational stability.

[0114] 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.

[0115] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A membrane for hydrogen production via water electrolysis, characterized in that, include: Substrate layer; A porous hydrophilic layer is disposed on at least one surface of the substrate layer. The porous hydrophilic layer contains a plurality of modified inorganic particles. The modified inorganic particles include inorganic particles and a modifying material coating at least a portion of the surface of the inorganic particles. The modified material has the following structural formula: Among them, R 11 R 12 and R 13 Each of the following components is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group; and the number average molecular weight of the modified material is 200-2000.

2. The water electrolysis hydrogen production membrane as described in claim 1, characterized in that, The modified material R2 contains at least one of polyoxyethylene segments and polyoxypropylene segments.

3. The water electrolysis hydrogen production membrane as described in claim 1, characterized in that, The porous hydrophilic layer satisfies at least one of the following conditions: (1) The porous hydrophilic layer contains the modified material at a mass of 0.1% to 1% of the inorganic particles; (2) The inorganic particles contained in the porous hydrophilic layer account for 70% to 90% of the total mass.

4. The water electrolysis hydrogen production membrane as described in claim 1, characterized in that, The porous hydrophilic layer also satisfies at least one of the following conditions: (1) The porosity of the porous hydrophilic layer is 50%~65%, and the average pore size is 80nm~120nm; (2) The thickness of the porous hydrophilic layer is 100μm~150μm.

5. The water electrolysis hydrogen production membrane according to any one of claims 1-4, characterized in that, The water electrolysis hydrogen production membrane satisfies at least one of the following conditions: (1) The material of the porous hydrophilic layer includes at least one of polysulfone resin, sulfonated polysulfone, polyethersulfone, polyetheretherketone resin and polyphenylene sulfide resin; (2) The inorganic particles are made of at least one of zirconium dioxide, titanium dioxide and silicon dioxide; (3) The particle size D90 of the inorganic particles is less than 1 μm; (4) The substrate layer includes at least one layer of polyphenylene sulfide mesh, polypropylene mesh and nylon mesh.

6. A method for preparing a water electrolysis hydrogen production membrane, characterized in that, The preparation method includes: A mixture comprising inorganic particles and a modifying material is prepared, such that the modifying material coats at least a portion of the surface of the inorganic particles to form modified inorganic particles; the structural formula of the modifying material is: Among them, R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or alkoxy group; R2 contains a polyether segment; R3 is a C1-C6 alkyl group; the number average molecular weight of the modified material is 200-2000; A resin material and a pore-forming agent are added to the mixture to form a casting solution; the casting solution is then coated onto at least one side of the substrate layer to form a wet film layer. After removing the pore-forming agent from the wet film layer, a porous hydrophilic layer containing a plurality of the modified inorganic particles is formed on the surface of the substrate layer.

7. The method for preparing the water electrolysis hydrogen production membrane as described in claim 6, characterized in that, The preparation method satisfies at least one of the following conditions: (1) The inorganic particles in the mixture account for 70% to 90% of the total mass, and the modified material accounts for 0.1% to 1% of the total mass of the inorganic particles. (2) The mass ratio of the resin material to the inorganic particles is 1:(5~8); (3) The mass of the pore-forming agent is 1% to 10% of the mass of the resin material.

8. The method for preparing the water electrolysis hydrogen production membrane as described in claim 6, characterized in that, The preparation method also satisfies at least one of the following conditions: (1) The mixture is formed by at least one of stirring, ball milling and ultrasonication; (2) Before forming the wet film layer, the preparation method further includes: degassing the casting solution.

9. The method for preparing the water electrolysis hydrogen production membrane according to any one of claims 6-8, characterized in that, The pore-forming agent was removed by a coagulation bath phase inversion method. Optionally, the solvent used for the coagulation bath phase inversion includes at least one of water, ethanol, and methanol; Optionally, the phase transformation temperature of the coagulation bath is 5℃~80℃.

10. A device for producing hydrogen through water electrolysis, characterized in that, The water electrolysis hydrogen production device includes a water electrolysis hydrogen production membrane prepared by any one of claims 1-5 or any one of claims 6-9.

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