Preparation method of composite anion exchange membrane and electrochemical device

Abstract

The invention provides a preparation method of a composite anion exchange membrane and an electrochemical device. The preparation method of the composite anion exchange membrane comprises the following steps: mixing anion exchange resin, a plasticizer and a solvent to obtain blended slurry; respectively carrying out film forming treatment on the blended slurry on two sides of a porous substrate to obtain a composite film; and carrying out ion exchange treatment on the composite membrane by using an ion exchange liquid to obtain the composite anion exchange membrane. A plasticizer is introduced, the plasticizer and anion exchange resin are blended in a solvent to form blended slurry, the plasticizer can be inserted between polymer molecular chains of the anion exchange resin, the interaction force between the polymer molecular chains is weakened, the mobility and flexibility of the molecular chains are improved, and the viscosity of the blended slurry is reduced; therefore, when the blended slurry forms a membrane on the porous substrate, the blended slurry can effectively infiltrate the porous substrate, so that the compatibility between the anion exchange resin and the porous substrate is improved, and the performance of the composite anion exchange membrane is improved.

Description

Technical Field

[0001] This application relates to the field of membrane technology, specifically to a method for preparing a composite anion exchange membrane and an electrochemical device thereof. Background Technology

[0002] Anion exchange membranes (AEMs) are the core components of alkaline electrochemical devices; their function is to convert anions (hydroxyl radicals) into hydroxide ions (OH radicals). - Anion exchange membranes conduct electricity from the cathode to the anode, while simultaneously preventing direct transfer of gas and electrons between the electrodes (cathode and anode). In alkaline electrochemical devices, anion exchange membranes should be as thin as possible while ensuring sufficient mechanical strength. Thinner membranes exhibit lower ohmic resistance during water electrolysis, resulting in better performance. However, developing ultrathin anion exchange membranes presents challenges related to thickness and mechanical stability. Thinner membranes, due to water absorption and size swelling, compromise the mechanical stability of anion exchange, increasing the risk of membrane breakage.

[0003] Related technologies employ a strategy of preparing composite anion exchange membranes with porous substrates to address the challenges of thickness and mechanical stability faced by anion exchange membranes. However, during the membrane formation process of composite anion exchange membranes, the poor compatibility between the anion exchange resin and the porous substrate affects the performance of the composite anion exchange membrane. Summary of the Invention

[0004] The embodiments of this application provide a method for preparing a composite anion exchange membrane and an electrochemical device, which can improve the technical problem of poor compatibility between anion exchange resin and porous substrate.

[0005] In a first aspect, embodiments of this application provide a method for preparing a composite anion exchange membrane, comprising: Anion exchange resin, plasticizer, and solvent are mixed to obtain a blended slurry; The blended slurry is subjected to film-forming treatment on both sides of a porous substrate to obtain a composite membrane; The composite membrane is subjected to ion exchange treatment using an ion exchange solution to obtain a composite anion exchange membrane.

[0006] This application embodiment introduces a plasticizer, which is blended with anion exchange resin in a solvent to form a blend slurry. During this process, the plasticizer inserts between the polymer molecular chains of the anion exchange resin, weakening the interaction forces between the polymer molecular chains, increasing the mobility and flexibility of the molecular chains, and reducing the viscosity of the blend slurry. Thus, when the blend slurry forms a film on a porous substrate, it can effectively wet the porous substrate, thereby improving the compatibility between the anion exchange resin and the porous substrate, enhancing the reliability of the bonding between the anion exchange resin and the porous substrate, and thus improving the performance of the composite anion exchange membrane.

[0007] In one embodiment, the mixing of anion exchange resin, plasticizer, and solvent to obtain a blended slurry includes: Anion exchange resin is added to a solvent to obtain anion exchange resin slurry; A plasticizer is added to the anion exchange resin slurry to obtain a blended slurry.

[0008] By adding the anion exchange resin and plasticizer to the solvent in steps, it is easier to control the viscosity of the blended slurry.

[0009] In one embodiment, the solid content of the anion exchange resin slurry is 10wt% to 60wt%.

[0010] By controlling the solid content in the anion exchange resin slurry, the viscosity of the blended slurry can be effectively controlled, thereby enabling the blended slurry to better wet the porous substrate and improve the compatibility between the porous substrate and the anion exchange resin.

[0011] In one embodiment, at 25°C, the viscosity of the anion exchange resin slurry is 1000 mPa·s to 80000 mPa·s.

[0012] By controlling the viscosity of the anion exchange resin slurry, the viscosity of the blended slurry can be indirectly controlled, thereby ensuring the compatibility between the anion exchange resin and the porous substrate in the composite membrane, as well as the forming quality of the composite membrane.

[0013] In one embodiment, the solid content of the anion exchange resin slurry is 15wt%~30wt%.

[0014] Reducing the solid content of the anion exchange resin slurry increases the distance between polymer molecules of the anion exchange resin in the blended slurry, reduces the interaction between polymer molecules, thereby reducing the viscosity of the blended slurry, improving the wetting effect of the blended slurry on porous substrates, and improving compatibility.

[0015] In one embodiment, the viscosity of the anion exchange resin slurry is 4000 mPa·s to 60000 mPa·s at 25°C.

[0016] When the viscosity of the anion exchange resin slurry is within the above range, the blended slurry can be used to prepare composite membranes by casting, and the blended slurry can also effectively wet porous substrates.

[0017] In one embodiment, the plasticizer content in the blended slurry is 0.5 wt% to 20 wt%.

[0018] By controlling the content of plasticizer in the blended slurry within the above-mentioned range, the anion exchange resin and the porous substrate can be effectively bonded together, and the composite anion exchange membrane can also have high strength.

[0019] In one embodiment, the plasticizer has a relative molecular mass of 100 to 500.

[0020] By controlling the relative molecular mass of the plasticizer within the above range, the steric hindrance of the plasticizer can be reduced, allowing the plasticizer to effectively insert between the molecular chains of the anion exchange resin, thereby reducing the viscosity of the blend slurry and improving the wetting effect of the blend slurry on the porous substrate.

[0021] In one embodiment, the plasticizer comprises at least one of the following substances: , , , , , .

[0022] The aforementioned plasticizers not only have good compatibility with anion exchange resins, but are also inexpensive, readily available, and have low toxicity.

[0023] In one embodiment, the solvent is an organic solvent, which includes at least one selected from dimethyl sulfoxide, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and acetonitrile.

[0024] The aforementioned organic solvents are highly polar, which facilitates the dissolution of anion exchange resins and plasticizers within them. This allows the plasticizers to be more evenly dispersed in the anion exchange resins, weakens the intermolecular interactions of the anion exchange resins, and reduces the viscosity of the blended slurry.

[0025] In one embodiment, the ion exchange solution is an alkaline solution, which is used to alkalize the composite membrane, and the resulting composite anion exchange membrane is a hydroxide-type anion exchange membrane.

[0026] By alkalizing the composite membrane with an alkaline solution, the anions in the composite membrane are replaced with hydroxide ions, thus obtaining a hydroxide-type anion exchange membrane. This hydroxide-type anion exchange membrane can attract and conduct OH- ions. - ion.

[0027] In one embodiment, the method for preparing the composite anion exchange membrane further includes: filtering the blended slurry with a 2000-6000 mesh filter cloth before the film-forming treatment.

[0028] Filtration can remove some impurities from the blended slurry, thus improving the film-forming effect.

[0029] In one embodiment, the step of forming a composite membrane by depositing the blended slurry on both sides of a porous substrate includes: The blended slurry is coated on the surface of the base film to obtain the first wet film layer; A porous substrate is laid on the surface of the first wet film layer facing away from the base film; The first wet film layer is subjected to a first drying treatment; The blended slurry is coated onto the surface of the porous substrate on the side opposite to the first wet film layer to obtain a second wet film layer. The second wet film layer is subjected to a second drying process; The base film is removed to obtain a composite film.

[0030] The above operation process is simple and easy to scale up.

[0031] In one embodiment, the total thickness of the first wet film layer and the second wet film layer is 30 μm to 1000 μm.

[0032] The thickness of the composite anion exchange membrane can be adjusted by controlling the total thickness of the first and second wet membrane layers, ensuring that the composite anion exchange membrane has sufficient mechanical stability and good ion transport efficiency.

[0033] In one embodiment, the preparation process of the blended slurry includes: adding a plasticizer to the anion exchange resin slurry and physically blending and stirring at 60°C to 80°C to obtain the blended slurry.

[0034] Heating and stirring can promote the molecular movement of plasticizers, thereby accelerating the mixing of plasticizers with anion exchange resins and improving efficiency and mixing effect.

[0035] In one embodiment, the general structural formula of the anion exchange resin is shown in formula (Ⅰ): Equation (Ⅰ); Ar is selected from substituted or unsubstituted aryl groups; R1 and R3 are each independently selected from one of the following: alkyl chain, hydrogen, heteroatom group, and polycyclic ring structure; R2 is selected from alkyl chains and polycyclic ring structures; R4, R5, R6, R7, and R8 are each independently selected from one of hydrogen, alkyl, alkenyl, alkynyl, and aromatic rings; Z - It is an anion; x, y, and z are each any number between 0 and 1, x + y + z = 1, at least one of x, y, and z is not 0, and when x is not 0, at least one of y and z is not 0; n is an integer between 10 and 1,000,000.

[0036] The molecular chain of the anion exchange resin is an ether-free polymer backbone, which is bonded with piperidine cationic groups and / or quinine cationic groups, thus giving the anion exchange membrane excellent alkali resistance.

[0037] In one embodiment, Z - Selected from OH - Cl - ,Br - HCO3 - CO3 2- NO3 - CF3COO - CH3COO - and R0SO3 - One or more of the following; wherein R0 is an organic group.

[0038] In one embodiment, R0 is selected from methyl, ethyl, vinyl, cyclopropyl, trifluoromethyl, phenyl, tolyl, nitrophenyl and benzyl.

[0039] In one embodiment, the alkyl chain has 10 or fewer carbon atoms.

[0040] In one embodiment, the heteroatomic group includes at least one of Br, Cl, F, N, O, and S.

[0041] In one embodiment, the multi-ring structure includes at least one of a ternary ring, a quaternary ring, a pentagonal ring, and a hexagram ring.

[0042] In the above situations, anion exchange resins exhibit better overall performance.

[0043] In one embodiment, the preparation process of the anion exchange resin includes: The first monomer and the second monomer are polymerized under superacid catalysis to form a multi-component copolymer intermediate, wherein the first monomer includes at least one of aryl monomers and carbonyl monomers, and the second monomer includes at least one of piperidinone monomers and quininecycloketone monomers. The anion exchange resin is obtained by quaternizing the multi-component copolymer intermediate, and the anion exchange resin is a quaternized anion exchange resin.

[0044] The above-mentioned method for preparing anion exchange resin can effectively prepare quaternized anion exchange resin. Quaternized anion exchange resin has strong basicity, high exchange capacity and good thermal stability, which effectively improves the performance of composite anion exchange membrane.

[0045] In one embodiment, the aryl monomer includes at least one selected from biphenyl, p-terphenyl, m-terphenyl, p-tetraphenyl, diphenylmethane, 1,3,5-triphenylbenzene, triphenylmethane, 9,10-benzophenanthrene, tetraphenylmethane, triphenylene, 9,9'-diphenylfluorene, 9,9'-spirobifluorene, 9,9'-bifluorene, 9,9'-bicarbazole, 2,2'-bi-9,9'-spirobi[9H-fluorene], 4,4-bis(9-carbazole)biphenyl, and triphenylamine.

[0046] In one embodiment, the carbonyl monomer includes at least one of butanedione, trifluoroacetone, and hydroxyacetone.

[0047] In one embodiment, the piperidone monomer comprises at least one of the following substances: .

[0048] In one embodiment, the quinine cyclic ketone monomer comprises at least one of the following substances: .

[0049] Using the above-mentioned monomers to prepare anion exchange resins can effectively reduce the difficulty of preparing anion exchange resins.

[0050] In one embodiment, the porous substrate is a mesh fabric.

[0051] The mesh fabric has a mesh structure, which not only has good air permeability, but also flexibility and tear resistance. This allows the composite anion exchange membrane to not only have good mechanical stability, but also high ion transport efficiency.

[0052] In one embodiment, the material of the mesh includes at least one of polyetheretherketone, polyphenylene sulfide, polyphenylene sulfone, polyethylene terephthalate, polypropylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, liquid crystal polymer, and polyethersulfone.

[0053] The above-mentioned materials have high temperature resistance, chemical stability and good mechanical properties, which are beneficial to improving the performance of the mesh fabric.

[0054] In one embodiment, the thickness of the mesh fabric is 5μm to 250μm.

[0055] In one embodiment, the mesh size of the mesh fabric is 20μm to 200μm.

[0056] The performance of the mesh can be controlled by adjusting its thickness and the size of the mesh openings.

[0057] Secondly, embodiments of this application provide an electrochemical device comprising a composite anion exchange membrane prepared by the above-described method for preparing a composite anion exchange membrane.

[0058] The electrochemical device includes the composite anion exchange membrane prepared by the above-mentioned method. Therefore, the electrochemical device has all the beneficial effects of the above-mentioned composite anion exchange membrane, which will not be elaborated here.

[0059] In one embodiment, the electrochemical device includes at least one of a battery and a water electrolysis hydrogen production device. Detailed Implementation The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0060] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0061] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0062] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0063] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0064] Anion exchange membranes (AEMs) are membrane materials with specific functions. They are typically composed of ionic polymers with anion-exchange functional groups attached to their main polymer chain. The core function of anion exchange membranes is to exchange anions (such as hydroxide ions, OH-) through these functional groups on the polymer main chain. - or chloride ions Cl - Selective conduction of anion exchangers. Anion exchange functional groups are typically positively charged cationic groups. As an example, the anion exchange functional group is selected from at least one of quaternary ammonium salt groups, imidazole salt groups, and guanidine groups.

[0065] Anion exchange membranes have a wide range of applications in many fields, including but not limited to water electrolysis for hydrogen production and alkaline fuel cells.

[0066] Some embodiments of this application provide an electrochemical device including an anion exchange membrane. An electrochemical device refers to a device in which an electrochemical reaction can occur. The core of the electrochemical device is an electrode system, including an anode and a cathode. An oxidation reaction occurs at the anode, and a reduction reaction occurs at the cathode. The electrochemical device includes an anion exchange membrane located between the anode and the cathode. Optionally, the electrochemical device includes a battery and an electrolysis device. The battery includes an alkaline fuel cell, such as an anion exchange membrane fuel cell (AEMFCs), and the electrolysis device includes a water electrolysis device for hydrogen production, such as an anion exchange membrane water electrolysis device (AEM-WE).

[0067] In some embodiments of this application, the electrochemical device includes a water electrolysis hydrogen production device, which includes an anion exchange membrane. The water electrolysis hydrogen production device is a device that generates hydrogen and oxygen by electrolyzing water molecules. In the water electrolysis hydrogen production device, the anion exchange membrane is OH-. -The anion exchange membrane is a type of hydrogen-oxygen anion exchange membrane. In water electrolysis hydrogen production devices, the anion exchange membrane can conduct hydroxide ions, causing them to migrate from the cathode side to the anode side, thus improving the efficiency of the water electrolysis process. The anion exchange membrane also plays a role in physical isolation in water electrolysis hydrogen production devices, preventing hydrogen and oxygen from mixing on both sides of the membrane, thereby improving the safety of the water electrolysis process.

[0068] Electrolysis of water to produce hydrogen typically includes a cathode and an anode, which are positioned opposite each other and located on opposite sides of an anion exchange membrane. During water electrolysis, when an electric current passes through the water, water molecules are broken down into hydrogen ions (H+). + ) and hydroxide ions (OH) - At the cathode (negative electrode), hydrogen ions are reduced to hydrogen gas; at the anode (positive electrode), hydroxide ions are oxidized to oxygen gas, i.e., the oxygen evolution reaction (OER) occurs at the anode and the hydrogen evolution reaction (HER) occurs at the cathode.

[0069] When electrolyzing water to produce hydrogen, the electrolyte used in the water electrolysis device can be water or an alkaline aqueous solution, i.e., an alkaline solution.

[0070] In some embodiments of this application, the anode includes an anode catalyst layer, which is the primary site for the oxygen evolution reaction. The anode catalyst layer is typically composed of a noble metal or its oxide, such as platinum (Pt), iridium (Ir), ruthenium (Ru), etc.

[0071] In some embodiments of this application, the cathode includes a cathode catalyst layer, which is the main site where the hydrogen evolution reaction occurs. The material of the cathode catalyst layer can be selected from noble metal-based catalysts, such as Pt / C and Ir / C, or from non-noble metal-based catalysts, such as Ni, NiMo, and NiP.

[0072] In some embodiments of this application, the water electrolysis hydrogen production device further includes a gas diffusion layer (GDL). The gas diffusion layer comprises a first gas diffusion layer and a second gas diffusion layer. The first gas diffusion layer is located on the side of the anode catalyst layer away from the anion exchange membrane, and the second gas diffusion layer is located on the side of the cathode catalyst layer away from the anion exchange membrane. The first gas diffusion layer assists in the rapid diffusion and discharge of gaseous products (such as oxygen) from the anode catalyst layer, and also assists in the transport of electrolyte to the anode catalyst layer, ensuring a sufficient supply of reactants. The second gas diffusion layer assists in the rapid diffusion and discharge of gaseous products (such as hydrogen) from the cathode catalyst layer, and also assists in the transport of electrolyte to the cathode catalyst layer, ensuring a sufficient supply of reactants. Exemplarily, the gas diffusion layer is made of carbon fiber or graphene material, thus giving it good electrical conductivity and permeability. It can be seen that the catalytic layer (including the cathode catalytic layer and the anode catalytic layer) and the gas diffusion layer work together in the process of producing hydrogen by water electrolysis. The catalytic layer is responsible for accelerating the reaction, while the gas diffusion layer is responsible for the transport of gas and liquid. The two work together to ensure the high efficiency of the electrolysis reaction.

[0073] In some embodiments of this application, the water electrolysis hydrogen production device further includes a bipolar plate, which includes a first electrode plate and a second electrode plate. The first electrode plate is located on the side of the anode catalyst layer away from the anion exchange membrane, and a first gas diffusion layer is located between the first electrode plate and the anode catalyst layer. The second electrode plate is located on the side of the cathode catalyst layer away from the anion exchange membrane, and a second gas diffusion layer is located between the second electrode plate and the cathode catalyst layer.

[0074] In a first aspect, embodiments of this application provide a method for preparing a composite anion exchange membrane, comprising: S1. Mix anion exchange resin, plasticizer and solvent to obtain a blended slurry; S2. The blended slurry is subjected to film-forming treatment on both sides of the porous substrate to obtain a composite membrane; S3. The composite membrane is subjected to ion exchange treatment using an ion exchange solution to obtain a composite anion exchange membrane.

[0075] In composite membranes, a porous substrate acts as a carrier to support the anion exchange resin, enhancing the mechanical stability of the composite membrane and ultimately reducing the risk of rupture. However, the bonding effect between the anion exchange resin and the porous substrate can affect the performance of the composite anion exchange membrane, such as its conductivity and gas permeability.

[0076] It should be noted that the film-forming process of the blended slurry on a porous substrate includes, but is not limited to, casting. If the film formed by curing the blended slurry is called a blended film, then the porous substrate is located within the blended film, and the blended film is attached to the porous substrate.

[0077] This application embodiment introduces a plasticizer, which is blended with anion exchange resin in a solvent to form a blend slurry. During this process, the plasticizer inserts between the polymer molecular chains of the anion exchange resin, weakening the interaction forces between the polymer molecular chains, increasing the mobility and flexibility of the molecular chains, and reducing the viscosity of the blend slurry. Thus, when the blend slurry forms a film on a porous substrate, it can effectively wet the porous substrate, thereby improving the compatibility between the anion exchange resin and the porous substrate, enhancing the reliability of the bonding between the anion exchange resin and the porous substrate, and thus improving the performance of the composite anion exchange membrane.

[0078] In some embodiments of this application, step S1: mixing anion exchange resin, plasticizer, and solvent to obtain a blended slurry includes: S11. Add the anion exchange resin to the solvent to obtain anion exchange resin slurry; S12. Add plasticizer to anion exchange resin slurry to obtain blended slurry.

[0079] By adding the anion exchange resin and plasticizer to the solvent in stages, the viscosity of the blended slurry can be better controlled. Generally, if a lower viscosity of the blended slurry is required, the amount of plasticizer introduced can be increased; if a higher viscosity of the blended slurry is required, the amount of plasticizer introduced can be decreased.

[0080] In some embodiments of this application, the solid content of the anion exchange resin slurry is 10wt% to 60wt%.

[0081] The solid content of anion exchange resin slurry refers to the total content of substances other than solvent in the anion exchange resin slurry. When the anion exchange resin slurry contains only anion exchange resin and solvent, the solid content of the anion exchange resin slurry is simply the content of anion exchange resin in the anion exchange resin slurry. Since blended slurries are obtained by introducing plasticizers into anion exchange resin slurries, the solid content of the anion exchange resin slurry will affect the solid content of the blended slurry to a certain extent, which in turn affects the viscosity of the blended slurry. The viscosity of the blended slurry, in turn, affects the wetting effect of the blended slurry on porous substrates.

[0082] Therefore, by controlling the solid content in the anion exchange resin slurry, the viscosity of the blended slurry can be effectively controlled, thereby enabling the blended slurry to better wet the porous substrate and improve the compatibility between the porous substrate and the anion exchange resin.

[0083] As an example, the solid content of the anion exchange resin slurry is a range of any one or any two of 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, and 60wt%.

[0084] In some embodiments of this application, the viscosity of the anion exchange resin slurry is 1000 mPa·s to 80000 mPa·s at 25°C. Controlling the viscosity of the anion exchange resin slurry can indirectly control the viscosity of the blended slurry, thereby ensuring the compatibility between the anion exchange resin and the porous substrate in the composite membrane, as well as the molding quality of the composite membrane. As an example, the viscosity of the anion exchange resin slurry is within the range of any one or any two of 1000 mPa·s, 5000 mPa·s, 10000 mPa·s, 20000 mPa·s, 30000 mPa·s, 40000 mPa·s, 50000 mPa·s, 60000 mPa·s, 70000 mPa·s, and 80000 mPa·s. It should be noted that methods for controlling the viscosity of the blended slurry include, but are not limited to, controlling the content of anion exchange resin and / or plasticizer in the blended slurry.

[0085] In some embodiments of this application, the solid content of the anion exchange resin slurry is 15wt% to 30wt%. Reducing the solid content of the anion exchange resin slurry increases the distance between polymer molecules of the anion exchange resin in the blended slurry, reduces the interaction between polymer molecules, thereby reducing the viscosity of the blended slurry, improving the wetting effect of the blended slurry on porous substrates, and improving compatibility. As an example, the solid content of the anion exchange resin slurry is any one or any two of 15wt%, 16wt%, 18wt%, 20wt%, 22wt%, 24wt%, 26wt%, 28wt%, and 30wt%.

[0086] In some embodiments of this application, the viscosity of the anion exchange resin slurry is 4000 mPa·s to 60000 mPa·s at 25°C. When the viscosity of the anion exchange resin slurry is within the above range, the blended slurry is suitable for preparing composite membranes by casting, and the blended slurry can also effectively wet porous substrates. As an example, the viscosity of the anion exchange resin slurry is any or any combination of 4000 mPa·s, 4200 mPa·s, 4400 mPa·s, 4600 mPa·s, 4800 mPa·s, 5000 mPa·s, 5200 mPa·s, 5400 mPa·s, 5600 mPa·s, 5800 mPa·s, and 60000 mPa·s.

[0087] In some embodiments of this application, the plasticizer content in the blended slurry is 0.5 wt% to 20 wt%. Increasing the plasticizer content in the blended slurry can reduce the viscosity of the blended slurry and improve its compatibility with the porous substrate. However, excessive plasticizer content will reduce the cohesion of the composite anion exchange membrane, affecting its strength. Therefore, by controlling the plasticizer content in the blended slurry within the above-mentioned range, the anion exchange resin and the porous substrate can be effectively bonded, and the composite anion exchange membrane can possess high strength. As an example, the plasticizer content in the blended slurry is any one or any two of the following: 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, and 20 wt%.

[0088] In some embodiments of this application, the relative molecular mass of the plasticizer is 100-500. In this case, the plasticizer is a small molecule organic compound. Relative molecular mass refers to the sum of the relative atomic masses of all atoms in a molecule. As an organic compound, the larger the relative molecular mass of the plasticizer, the larger the volume of the plasticizer molecule, for example, the longer the plasticizer molecular chain. This increases the steric hindrance of the plasticizer, which is detrimental to its insertion between the polymer molecular chains of the anion exchange resin. Therefore, by controlling the relative molecular mass of the plasticizer within the above range, the steric hindrance of the plasticizer can be reduced, allowing the plasticizer to effectively insert between the molecular chains of the anion exchange resin, thereby reducing the viscosity of the blend slurry and improving the wetting effect of the blend slurry on the porous substrate. As an example, the relative molecular mass of the plasticizer is any one or any two of 100, 150, 200, 250, 300, 350, 400, 450, and 500.

[0089] In some embodiments of this application, the plasticizer includes at least one of the following substances: , , , , , .

[0090] The aforementioned plasticizers not only have good compatibility with anion exchange resins, but are also inexpensive, readily available, and have low toxicity.

[0091] In some embodiments of this application, the solvent is an organic solvent, including at least one selected from dimethyl sulfoxide, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and acetonitrile.

[0092] Anion exchange resin is an organic polymer. According to the principle of "like dissolves like", anion exchange resin can be dissolved in organic solvents. When anion exchange resin is completely dissolved in an organic solvent, the resulting anion exchange resin slurry is a clear and transparent solution.

[0093] Plasticizers are usually organic compounds and can be dissolved in organic solvents. When the plasticizer is completely dissolved, the resulting blend slurry is a clear and transparent solution.

[0094] Specifically, the organic solvent includes at least one of dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), and acetonitrile (MeCN).

[0095] The aforementioned organic solvents are highly polar, which facilitates the dissolution of anion exchange resins and plasticizers within them. This allows the plasticizers to be more evenly dispersed in the anion exchange resins, weakens the intermolecular interactions of the anion exchange resins, and reduces the viscosity of the blended slurry.

[0096] In some embodiments of this application, the ion exchange solution is an alkaline solution, which is used to alkalize the composite membrane, and the resulting composite anion exchange membrane is a hydroxide-type anion exchange membrane.

[0097] Alkaline solution refers to an alkaline solution, such as an aqueous solution of NaOH. Optionally, the concentration of hydroxide ions in the alkaline solution is 1 mol / L to 2 mol / L. As examples, the concentration of hydroxide ions in the alkaline solution is 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, or 2 mol / L.

[0098] By alkalizing the composite membrane with an alkaline solution, the anions in the composite membrane are replaced with hydroxide ions, thus obtaining a hydroxide-type anion exchange membrane. This hydroxide-type anion exchange membrane can attract and conduct OH- ions. - ion.

[0099] In some embodiments of this application, the method for preparing the composite anion exchange membrane further includes: filtering the blended slurry using a 2000-6000 mesh filter cloth before the film-forming process. Filtration can remove some impurities from the blended slurry, improving the film-forming effect. As an example, the filter cloth is 2000 mesh, 3000 mesh, 4000 mesh, 5000 mesh, or 6000 mesh.

[0100] In some embodiments of this application, step S2: performing film-forming treatment on both sides of the porous substrate to obtain a composite membrane includes: S21. The blended slurry is coated on the surface of the base film to obtain the first wet film layer; S22. A porous substrate is laid on the surface of the first wet film layer away from the base film. S23. Perform a first drying treatment on the first wet film layer; S24. The blended slurry is coated on the surface of the porous substrate away from the first wet film layer to obtain the second wet film layer. S25. Perform a second drying treatment on the second wet film layer; S26. Remove the base film to obtain the composite film.

[0101] The first and second wet film layers contain solvents. The first and second drying processes are solvent removal processes. After drying, the wet film layers are obtained as dry film layers, i.e., composite films. The composite films contain no solvents or have very low solvent content. Optionally, the base film is a polymer film, such as polyethylene terephthalate film (PET film).

[0102] The above operation process is simple and easy to scale up.

[0103] In some embodiments of this application, the total thickness of the first wet film layer and the second wet film layer is 30 μm to 1000 μm.

[0104] The total thickness of the first and second wet membrane layers affects the thickness of the composite membrane and ultimately the thickness of the composite anion exchange membrane. The thickness of the composite anion exchange membrane affects its performance; generally, a greater thickness results in better mechanical stability, but also increases the resistance of ions passing through the membrane, reduces ion transport efficiency, and increases ohmic loss during use.

[0105] The thickness of the composite anion exchange membrane can be adjusted by controlling the total thickness of the first and second wet membrane layers, ensuring that the composite anion exchange membrane has sufficient mechanical stability and good ion transport efficiency.

[0106] As an example, the total thickness of the first wet film layer and the second wet film layer is 30 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm and 1000 μm.

[0107] In some embodiments of this application, the preparation process of the blended slurry in step S12 includes: adding a plasticizer to anion exchange resin slurry and physically blending and stirring at 60°C to 80°C to obtain a blended slurry. Heating and stirring can promote the molecular movement of the plasticizer, thereby accelerating the mixing of the plasticizer and the anion exchange resin, improving efficiency and mixing effect. As an example, the heating and stirring temperature is 60°C, 65°C, 70°C, 75°C, or 80°C.

[0108] In some embodiments of this application, the general structural formula of the anion exchange resin is shown in formula (Ⅰ): Equation (Ⅰ); Wherein, Ar is selected from substituted or unsubstituted aryl groups; R1 and R3 are each independently selected from one of alkyl chains, hydrogen, heteroatomic groups, and polycyclic ring structures; R2 is selected from one of alkyl chains and polycyclic ring structures; R4, R5, R6, R7, and R8 are each independently selected from one of hydrogen, alkyl, alkenyl, alkynyl, and aromatic rings; Z - The ion is an anion; x, y, and z are each independent arbitrary numbers between 0 and 1, x + y + z = 1, at least one of x, y, and z is not 0, and when x is not 0, at least one of y and z is not 0; n is an integer between 10 and 1000000.

[0109] The asterisk in the structure represents the connection point. As an example, n is a range of values ​​between any one or any two of 10, 100, 1000, 10000, 100000, and 1000000.

[0110] It is understandable that, depending on the values ​​of x, y, and z, equation (Ⅰ) can have many different specific forms.

[0111] As an example, when x=0, y=0, and z≠0, equation (Ⅰ) simplifies to the following form: .

[0112] As an example, when x=0, y≠0, z=0, equation (Ⅰ) simplifies to the following form: .

[0113] As an example, when x=0, y≠0, z≠0, equation (Ⅰ) simplifies to the following form: .

[0114] As an example, when x≠0, y=0, z≠0, equation (Ⅰ) simplifies to the following form: .

[0115] As an example, when x≠0, y≠0, and z=0, equation (Ⅰ) simplifies to the following form: .

[0116] As an example, when x≠0, y≠0, z≠0, equation (Ⅰ) is not simplified, and equation (Ⅰ) is as follows: .

[0117] It can be seen that the molecular chain of the anion exchange resin is an ether-free polymer backbone, which is bonded with piperidine cationic groups and / or quinine cationic groups, thus enabling the anion exchange membrane to have excellent alkali resistance.

[0118] In some embodiments of this application, Z - Selected from OH - Cl - ,Br - HCO3 - CO3 2- NO3 - CF3COO - CH3COO - and R0SO3 - One or more of the following; wherein R0 is an organic group. Optionally, R0 is selected from methyl, ethyl, vinyl, cyclopropyl, trifluoromethyl, phenyl, tolyl, nitrophenyl, and benzyl. As an example, the anion exchange resin is an anion exchange resin after alkalization treatment, Z - OH - .

[0119] In some embodiments of this application, the alkyl chain has 10 or fewer carbon atoms. Optionally, the alkyl chain can be R1, R2, or R3. As an example, the alkyl chain has 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. The alkyl chain can be straight or branched.

[0120] In some embodiments of this application, the heteroatomic groups include at least one of Br, Cl, F, N, O, and S.

[0121] In some embodiments of this application, the multi-ring structure includes at least one of a ternary ring, a quaternary ring, a pentagonal ring, and a hexagram ring. Optionally, the multi-ring structure may be R1, R2, or R3.

[0122] In the above situations, anion exchange resins exhibit better overall performance.

[0123] In some embodiments of this application, the preparation process of the anion exchange resin includes: The first monomer and the second monomer are polymerized under superacid catalysis to form a multi-component copolymer intermediate, wherein the first monomer includes at least one of aryl monomers and carbonyl monomers, and the second monomer includes at least one of piperidinone monomers and quinine cycloketone monomers. An anion exchange resin is obtained by quaternizing the multi-component copolymer intermediate. The anion exchange resin is a quaternized anion exchange resin.

[0124] Superacids are substances with extremely high acidity. Typically, superacids are stronger than 100% sulfuric acid. For example, superacids include at least one of trifluoroacetic acid, trifluoromethanesulfonic acid (CF3SO3H), and fluorosulfonic acid (HSO3F).

[0125] Depending on the monomers used in the polymerization reaction, different multi-component copolymer intermediates are obtained. Possible methods include: polymerizing aryl monomers with piperidinone monomers; polymerizing aryl monomers with quinine cyclic ketone monomers; polymerizing aryl monomers with both piperidinone and quinine cyclic ketone monomers; polymerizing carbonyl monomers with piperidinone monomers; polymerizing carbonyl monomers with both piperidinone and quinine cyclic ketone monomers; polymerizing aryl monomers and carbonyl monomers with both piperidinone and quinine cyclic ketone monomers; polymerizing aryl monomers and carbonyl monomers with both piperidinone and quinine cyclic ketone monomers.

[0126] Quaternization refers to the introduction of quaternary ammonium groups (-N) into organic compounds. + R3R4X - The chemical reaction process of quaternization. As an example, quaternization treatment includes dissolving a multi-component copolymer intermediate in an organic solvent, adding a quaternizing agent and reacting it with the multi-component copolymer intermediate to obtain a quaternized anion exchange resin. Optionally, the quaternizing agent is selected from one or more of iodomethane, iodoethane, iodopropane, iodobutane, iodopentane, iodohexane, bromoethane, bromopropane, bromobutane, bromopentane, bromohexane, bromocyclohexane, bromocyclopentane, bromocyclohexane, methyl methanesulfonate, ethyl methanesulfonate, propyl methanesulfonate, butyl methanesulfonate, propyl ethanesulfonate, ethyl ethanesulfonate, but-3-yn-1-yl methanesulfonate, allyl allyl sulfonate, methyl benzenesulfonate, methyl p-toluenesulfonate, methyl nitrobenzenesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, ethyl toluenesulfonate, cyclobutyl toluene-4-sulfonate, butyl toluenesulfonate, neopentylbenzenesulfonate, tetrahydro-2H-pyran-4-yl methanesulfonate, methyl trifluoroacetate, and cyclohexyl p-toluenesulfonate. Optionally, the quaternization reaction temperature is 70℃~85℃.

[0127] When quaternized anion exchange resins undergo a simplified treatment in an alkaline solution, the quaternary ammonium salt is converted into a quaternary ammonium base. As an example, the halide ions (X) in the quaternary ammonium salt... - ) and the OH- in strong bases (such as NaOH, KOH) - An exchange occurs, resulting in the formation of quaternary ammonium bases.

[0128] The above-mentioned method for preparing anion exchange resin can effectively prepare quaternized anion exchange resin. Quaternized anion exchange resin has strong basicity, high exchange capacity and good thermal stability, which effectively improves the performance of anion exchange membrane.

[0129] In some embodiments of this application, the aryl monomer includes at least one selected from biphenyl, p-terphenyl, m-terphenyl, p-tetraphenyl, diphenylmethane, 1,3,5-triphenylbenzene, triphenylmethane, 9,10-benzophenanthrene, tetraphenylmethane, tripterene, 9,9'-diphenylfluorene, 9,9'-spirodifluorene, 9,9'-bifluorene, 9,9'-bicarbazole, 2,2'-bi-9,9'-spirobis[9H-fluorene], 4,4-bis(9-carbazole)biphenyl, and triphenylamine.

[0130] In some embodiments of this application, the carbonyl monomer includes at least one of butanedione, trifluoroacetone, and hydroxyacetone.

[0131] In some embodiments of this application, the piperidone monomer includes at least one of the following substances: .

[0132] In some embodiments of this application, the quinine cyclic ketone monomer includes at least one of the following substances: .

[0133] Using the above-mentioned monomers to prepare anion exchange resins can effectively reduce the difficulty of preparing anion exchange resins.

[0134] In some embodiments of this application, the porous substrate is a mesh fabric. The mesh fabric has a mesh structure, which not only has good air permeability but also flexibility and tear resistance, thus enabling the composite anion exchange membrane to not only have good mechanical stability but also high ion transport efficiency.

[0135] In some embodiments of this application, the material of the mesh fabric includes at least one selected from polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), polyethylene terephthalate (PET), polypropylene (PP), polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), liquid crystal polymer (LCP), and polyethersulfone (PES). These materials possess high-temperature resistance, chemical stability, and good mechanical properties, which are beneficial for improving the performance of the mesh fabric.

[0136] In some embodiments of this application, the thickness of the mesh fabric is 5 μm to 250 μm. As an example, the thickness of the mesh fabric is within the range of any one or any two of 5 μm, 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, and 250 μm. By adjusting the thickness of the mesh fabric, its performance can be controlled, thereby improving the performance of the composite anion exchange membrane.

[0137] In some embodiments of this application, the pore size of the mesh fabric is 20 μm to 200 μm. As an example, the pore size is any one or a range between 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, and 200 μm. By adjusting the pore size of the mesh fabric, the performance of the mesh fabric can be controlled, thereby improving the performance of the composite anion exchange membrane.

[0138] In some embodiments of this application, the anion exchange membrane in the electrochemical device is a composite anion exchange membrane prepared by the above-described method for preparing composite anion exchange membranes.

[0139] The following description is based on specific embodiments.

[0140] Preparation Example 1 A binary copolymer polymer resin was obtained by reacting terphenyl with N-methyl-4-piperidinone under low-temperature catalysis in dichloromethane using superacids (trifluoroacetic acid and trifluoromethanesulfonic acid). This resin was then reacted with iodomethane as a quaternizing agent to prepare polyarylpiperidine anion exchange resin (PQAPPT), the structure of which is shown below: .

[0141] The intrinsic viscosity of the above-mentioned polyarylpiperidine anion exchange resin is 380s. The method for determining this intrinsic viscosity is as follows: take 10g of intermediate resin, crush it, add a certain amount of DMSO to prepare 40ml of 5mg / ml resin solution; place the viscosity tube containing pure solvent DMSO and the sample in a constant temperature bath; and use an automatic viscometer to test its intrinsic viscosity.

[0142] Preparation Example 2 A binary copolymer polymer resin was obtained by reacting terphenyl with quinine cyclic ketones under low-temperature catalysis in dichloromethane with superacids (trifluoroacetic acid and trifluoromethanesulfonic acid). This resin was then reacted with iodomethane as a quaternizing agent to prepare a polyarylquinine anion exchange resin, the structure of which is shown below: .

[0143] The intrinsic viscosity of the above-mentioned polyarylequinine anion exchange resin is 385s. For the method of measuring this intrinsic viscosity, please refer to the intrinsic viscosity measurement method in Preparation Example 1.

[0144] Preparation Example 3 A ternary copolymer polymer resin was obtained by reacting terphenyl, butanedione, and N-methyl-4-piperidinone with superacids (trifluoroacetic acid and trifluoromethanesulfonic acid) at low temperature in dichloromethane solvent. This resin was then reacted with iodomethane as a quaternizing agent to prepare a polycarbonylpiperidin anion exchange resin, the structure of which is shown below: .

[0145] The intrinsic viscosity of the above-mentioned polycarbonylpiperidine anion exchange resin is 378 s. For the method of measuring this intrinsic viscosity, please refer to the intrinsic viscosity measurement method in Preparation Example 1.

[0146] Preparation Example 4 A terpolymer polymer resin was obtained by reacting terphenyl, butanedione, and quinine cyclic ketone with superacids (trifluoroacetic acid and trifluoromethanesulfonic acid) at low temperature in dichloromethane solvent. This resin was then reacted with iodomethane as a quaternizing agent to prepare a polycarbonylquinine anion exchange resin, the structure of which is shown below: .

[0147] The intrinsic viscosity of the above-mentioned polycarbonylquinine anion exchange resin is 385s. For the method of measuring this intrinsic viscosity, please refer to the intrinsic viscosity measurement method in Preparation Example 1.

[0148] Preparation Example 5 A quaternary copolymer polymer resin was obtained by reacting terphenyl, butanedione, quinine cyclohexane, and N-methyl-4-piperidinone with superacids (trifluoroacetic acid and trifluoromethanesulfonic acid) in dichloromethane solvent at low temperature. This resin was then reacted with iodomethane as a quaternizing agent to prepare a polycarbonylquinine piperidine anion exchange resin, the structure of which is shown below: .

[0149] The intrinsic viscosity of the above-mentioned polycarbonylquinine piperidine anion exchange resin is 390s. For the method of measuring this intrinsic viscosity, please refer to the intrinsic viscosity measurement method in Preparation Example 1.

[0150] Example 1 This embodiment provides a composite anion exchange membrane, and the preparation process of the composite anion exchange membrane is as follows: S1. Take 20g of the polyarylpiperidine anion exchange resin (PQAPPT) provided in Preparation Example 1 and 80mL of dimethyl sulfoxide, heat and stir in a water bath at 80°C for 6h until completely dissolved to obtain a PQAPPT resin slurry with a solid content of 23wt%. S2. The plasticizer N-ethyl-p-toluenesulfonamide is physically mixed with PQAPPT resin slurry and stirred at room temperature for 1 hour to obtain a homogeneous solution containing N-ethyl-p-toluenesulfonamide; the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is 5 wt%; the structural formula of N-ethyl-p-toluenesulfonamide is shown below: ; S3. Filter the homogeneous solution containing N-ethyl-p-toluenesulfonamide using a 6000-mesh filter cloth. By adjusting the blade height, coat the homogeneous solution containing N-ethyl-p-toluenesulfonamide onto a flat PET base film with a coating thickness of 150 μm. Then, lay a 60 μm PPS mesh fabric flat on the coating surface and dry at 50℃ for 30 min. Next, coat a 430 μm thick coating onto the PPS mesh fabric surface and further dry at 60℃ for 2 h, 80℃ for 3 h, and finally at 70℃ for 1 h to obtain a composite film with a thickness of 100±5 μm. S4. After immersing the composite membrane in a 1 mol / L KOH solution at 60℃ for 48 hours, the final product is an OH-containing plasticizer N-ethyl-p-toluenesulfonamide. - Type of composite anion exchange membrane.

[0151] Example 2 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 2 and Example 1 is as follows: In S2, the plasticizer N-ethyl-p-toluenesulfonamide is replaced with triphenyl phosphate, the structural formula of which is shown below: .

[0152] Example 3 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 3 and Example 1 is as follows: In S2, the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is set to 0.5 wt%.

[0153] Example 4 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 4 and Example 1 is as follows: In S2, the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is set to 3 wt%.

[0154] Example 5 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 5 and Example 1 is as follows: In S2, the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is set to 7 wt%.

[0155] Example 6 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 6 and Example 1 is as follows: In S2, the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is set to 10 wt%.

[0156] Example 7 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 7 and Example 1 is as follows: In S2, the content of plasticizer N-ethyl-p-toluenesulfonamide in the homogeneous solution is set to 20 wt%.

[0157] Example 8 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 8 and Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polyarylquinine anion exchange resin provided in Preparation Example 2.

[0158] Example 9 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 9 and Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylpiperidine anion exchange resin provided in Preparation Example 3.

[0159] Example 10 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 10 and Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylquinine anion exchange resin provided in Preparation Example 4.

[0160] Example 11 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 11 and Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylpiperidine quinine anion exchange resin provided in Preparation Example 5.

[0161] Example 12 This embodiment provides a composite anion exchange membrane. The preparation method of the composite anion exchange membrane can be found in Example 1 and Table 1. The difference between Example 12 and Example 1 is as follows: S3. Filter the homogeneous solution containing N-ethyl-p-toluenesulfonamide using a 6000-mesh filter cloth. By adjusting the blade height, coat the homogeneous solution containing N-ethyl-p-toluenesulfonamide onto a flat PET base film with a coating thickness of 120 μm. Then, lay a 40 μm PEEK mesh on the coating surface and dry it at 50°C for 30 min. Next, coat a 400 μm thick coating onto the PEEK mesh surface and further dry it at 60°C for 2 h, 80°C for 3 h, and finally at 70°C for 1 h to obtain a composite film with a thickness of 100 ± 5 μm.

[0162] Comparative Example 1 This comparative example provides a composite anion exchange membrane, the preparation process of which includes: S1. Take 20g of the polyarylpiperidine anion exchange resin (PQAPPT) provided in Preparation Example 1 and 80mL of dimethyl sulfoxide, heat and stir in a water bath at 80°C for 6h until completely dissolved to obtain a PQAPPT resin slurry with a solid content of 23wt%. S2. After filtering the PQAPPT resin slurry with a 6000-mesh filter cloth, a homogeneous solution is obtained. S3. By adjusting the blade height, the homogeneous solution is coated onto a flat PET base film with a coating thickness of 150μm. Then, a 60μm PPS mesh is laid flat on the coating surface and dried at 50℃ for 30min. Next, a 430μm coating is coated on the PPS mesh surface, and then dried at 60℃ for 2h, 80℃ for 3h, and finally at 70℃ for 1h to obtain a composite film with a thickness of 100±5μm. S4. After immersing the composite membrane in a 1 mol / L KOH solution at 60℃ for 48 hours, the final OH... - Type of composite anion exchange membrane.

[0163] Comparative Example 2 This comparative example provides a composite anion exchange membrane. The preparation method of this composite anion exchange membrane can be found in Comparative Example 1 and Table 1. The difference between Comparative Example 2 and Comparative Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polyarylquinine anion exchange resin provided in Preparation Example 2.

[0164] Comparative Example 3 This comparative example provides a composite anion exchange membrane. The preparation method of this composite anion exchange membrane can be found in Comparative Example 1 and Table 1. The difference between Comparative Example 3 and Comparative Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylpiperidine anion exchange resin provided in Preparation Example 3.

[0165] Comparative Example 4 This comparative example provides a composite anion exchange membrane. The preparation method of this composite anion exchange membrane can be found in Comparative Example 1 and Table 1. The difference between Comparative Example 4 and Comparative Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylquinine anion exchange resin provided in Preparation Example 4.

[0166] Comparative Example 5 This comparative example provides a composite anion exchange membrane. The preparation method of this composite anion exchange membrane can be found in Comparative Example 1 and Table 1. The difference between Comparative Example 5 and Comparative Example 1 is as follows: In S1, the polyarylpiperidine anion exchange resin provided in Preparation Example 1 was replaced with the polycarbonylpiperidine quinine anion exchange resin provided in Preparation Example 5.

[0167] Comparative Example 6 This comparative example provides a composite anion exchange membrane, the preparation process of which includes: S1. Take 20g of the polyarylpiperidine anion exchange resin (PQAPPT) provided in Preparation Example 1 and 60mL of dimethyl sulfoxide and heat and stir in a water bath at 80°C for 6h until completely dissolved to obtain a PQAPPT resin slurry with a solid content of 23wt%. S2. After filtering the PQAPPT resin slurry with a 6000-mesh filter cloth, a homogeneous solution is obtained. S3. By adjusting the blade height, the homogeneous solution is coated onto a flat PET base film with a coating thickness of 120μm. Then, a 40μm PEEK mesh is laid flat and laminated onto the coating surface, and dried at 50℃ for 30min. Next, a 400μm thick coating is coated onto the PEEK mesh surface, and further dried at 60℃ for 2h, 80℃ for 3h, and finally at 70℃ for 1h to obtain a composite film with a thickness of 100±5μm. S4. After immersing the composite membrane in a 1 mol / L KOH solution at 60℃ for 48 hours, the final OH... - Type of composite anion exchange membrane.

[0168] Table 1

[0169] I. Performance Testing 1. Slurry viscosity test Test method: Using a syringe, take ≥10ml of the slurry to be tested into a container. Place the container into the viscosity test chamber of the integrated viscometer. Assemble the rotor and connector into a connection device. Set the test program, select the speed and range according to the type of rotor used, and start the test. The reading after the data stabilizes is the viscosity of the slurry.

[0170] Slurry preparation: Take 20g of the anion exchange resin provided in Preparation Example 1 and 80mL of dimethyl sulfoxide, heat and stir in a water bath at 80°C for 6h until completely dissolved to obtain a resin slurry without plasticizer; The plasticizer and resin slurry are physically mixed and stirred at room temperature for 1 hour to obtain the resin slurry with added plasticizer.

[0171] A series of slurries can be prepared by adjusting the content and type of plasticizer in the resin slurry after adding plasticizer. The viscosity of different slurries was tested, and the results are recorded in Table 2.

[0172] Table 2

[0173] As can be seen from Table 2, the viscosity of the slurry decreases after the addition of plasticizer. Furthermore, the viscosity reduction rate increases with the increase of the mass fraction of plasticizer in the slurry. However, the viscosity reduction rate tends to stabilize after the mass fraction of plasticizer in the slurry reaches 10 wt%.

[0174] 2. Mechanical performance testing The test method refers to GB / T 20042.3, and the test results are recorded in Table 3.

[0175] Anion exchange membranes were used as samples. The length and width of the samples were measured under constant temperature and humidity conditions of 23℃±2℃ and 50%±10% relative humidity. The samples were placed in the test fixture. Different tensile speeds, ranging from 50 mm / min to 200 mm / min, could be used to determine tensile strength and elongation at break. Each tensile speed should be applied to a separate sample. After the sample broke, the corresponding load value was recorded.

[0176] 2.1 Tensile strength: The ratio of the maximum load that an anion exchange membrane can withstand when it breaks under pure tensile force to the width of the stretched anion exchange membrane. It is divided into transverse and longitudinal tensile strength and is used to evaluate the mechanical strength of the membrane material. 2.2 Elongation at break: The ratio of the distance between two points at break under the maximum load before the anion exchange membrane breaks to its original length. Elongation at break represents the maximum deformation that the anion exchange membrane can withstand before breaking, and is used to indicate the flexibility of the anion exchange membrane.

[0177] 3. Water absorption and swelling performance test Test method: a. Cut the anion exchange membrane into 1cm×4cm pieces, immerse it in 1mol / L KOH solution and change the alkali three times, and test its swelling performance in deionized water at 80℃. b. Cut the anion exchange membrane into 5cm×5cm pieces, immerse it in a 1mol / L KOH solution to change the alkali three times, and test its water absorption performance in deionized water at 80℃.

[0178] The test results are recorded in Table 3.

[0179] 4. OH - Ion conductivity performance test The anion exchange membrane was cut into 10 mm × 45 mm samples. The samples were placed in a 1 mol / L KOH solution and ion exchanged at 80 °C for 24 h. After completion, the samples were washed with deionized water until neutral and stored in deionized water.

[0180] Before testing, the thickness and width of the anion exchange membrane sample were measured using a thickness gauge and a ruler, respectively. The average value of multiple test points was taken as the width 'a' and the thickness 'b'. At least 3 test points were taken for each sample group.

[0181] The ionic conductivity of the sample was tested using a four-electrode probe method. First, the sample was laid flat on top of the platinum wire electrode without any wrinkles to ensure good contact between the sample and the platinum wire electrode. Then, the top cover was gently placed on top and the screws were tightened with a wrench. After tightening, there should be no protrusions on the sample, thus completing the assembly of the test module.

[0182] Connect the test fixture to the temperature and humidity control system. After connection, purge with N2 (99.999%, the same below), setting the flow rate on both sides to 500 sccm. Set the humidification condition to 100% RH, ensuring the pipeline temperature is 5°C higher than the test device temperature; the actual test temperature should be set according to requirements. Then start the temperature and humidity control system, and begin the electrolysis process once the set conditions are reached, maintaining N2 purging throughout the process with a constant gas flow rate.

[0183] The sample to be tested is electrolyzed using a constant current method. The electrolysis current value can be adjusted within an electrolysis potential of 2V to meet actual testing requirements. During electrolysis, an electrochemical reaction occurs at the electrodes, causing carbonate (bicarbonate) ions in the anion exchange membrane to be released as CO2 gas, until all anions in the membrane are exchanged in situ for OH-. - Whether electrolysis has reached equilibrium is determined based on the change in overpotential during the test. Generally, when the potential fluctuation value is less than 1%, the electrolysis process is considered to be over and the system has reached equilibrium.

[0184] After electrolysis equilibrium, EIS testing was performed using a current perturbation mode with a frequency range of 0.1 Hz to 1.0 MHz and a perturbation amplitude of 1 mA to obtain the impedance spectrum. The impedance value R of the membrane sample was read from the intersection of the low-frequency portion of the spectrum with the real axis, and the in-plane ionic conductivity of the sample was calculated using the following formula: σ = l / (a×b×R) In the formula: σ — the in-plane ionic conductivity of the sample, in millisiemens per centimeter (mS / cm); l — the distance between electrodes, in centimeters (cm); a — the width of the membrane sample, in centimeters (cm); b — the thickness of the membrane sample, in centimeters (cm); R represents the measured impedance of the membrane sample, measured in ohms (Ω).

[0185] The test results are recorded in Table 3.

[0186] Table 3

[0187] As can be seen from Table 3, compared with Comparative Examples 1 to 6, Examples 1 and 8 to 12 show that when the composite anion exchange membrane contains plasticizer, the tensile strength of the composite anion exchange membrane decreases, the elongation at break increases, but the water absorption rate decreases, the swelling rate decreases, and the ionic conductivity decreases. This is because when plasticizers are included in composite anion exchange membranes, the plasticizer molecules insert into the polymer molecular chains of the anion exchange resin, weakening the stress between the polymer molecular chains, increasing the mobility of the polymer molecular chains, reducing the crystallinity of the polymer molecular chains, and improving the plasticity of the polymer. This results in a decrease in the cohesion of the composite anion exchange membrane, an increase in its toughness, and consequently a decrease in its tensile strength and an increase in its elongation at break. At the same time, plasticizers can reduce the viscosity of the slurry and improve its wettability in the porous substrate, allowing the slurry to better enter the pores of the porous substrate. This also reduces the porosity of the resulting composite anion exchange membrane, making it more difficult for water molecules to enter the composite anion exchange membrane, thus reducing its water absorption and swelling rate. In addition, as an impurity molecule, the plasticizer in the composite anion exchange membrane is easily hydrolyzed in an alkaline environment, which hinders ion conduction and reduces the ionic conductivity of the composite anion exchange membrane.

[0188] Compared with Example 2, Example 1 differs in the type of plasticizer, but the tensile strength, elongation at break, water absorption, swelling rate, and ionic conductivity of the composite anion exchange membrane are similar.

[0189] Comparing Examples 3, 4, 1, and 5 through 7, it can be seen that as the plasticizer content in the composite anion exchange membrane increases, the tensile strength of the composite anion exchange membrane decreases, the elongation at break increases, the water absorption rate decreases, the swelling rate decreases, and the ionic conductivity decreases. 5. Electrolysis performance test 5.1 Polarization Performance Test Test method: The polarization curve of a single cell of the alkaline membrane was tested at 60℃ in a 1 mol / L KOH solution under a nickel ferrite anode-platinum carbon cathode catalytic system. The current density of 1 A / cm² was obtained from the polarization curve. 2 The voltage data at that time were recorded in Table 4.

[0190] 5.2 Hydrogen in Oxygen Test The oxygen on the anode side of the nickel ferrite anode-platinum carbon cathode catalytic system was tested by gas chromatography (GC) to obtain the hydrogen data in the oxygen. The results are recorded in Table 4.

[0191] 5.3 Ohmic Impedance Test The ohmic impedance of the composite anion exchange membrane was tested using an electrochemical workstation under open-circuit conditions, and the results are recorded in Table 4.

[0192] Table 4

[0193] As can be seen from the structure in Table 4, compared with Comparative Examples 1 to 6, Examples 1 and 8 to 12 show that, compared with the case where the composite anion exchange membrane does not contain plasticizer, when the composite anion exchange membrane contains plasticizer, the application of the composite anion exchange membrane in the nickel ferrite anode-platinum carbon cathode catalytic system shows that the hydrogen content in the oxygen on the anode side is reduced, and the current density in the polarization curve is 1 A / cm. 2 As the voltage increases, the internal resistance of the composite anion exchange membrane also increases. This is because the presence of plasticizers in the composite anion exchange membrane reduces its porosity. This allows the membrane to better prevent hydrogen from the cathode side from passing through to the anode layer during water electrolysis, thus reducing the hydrogen content in the oxygen at the anode side. Simultaneously, the presence of plasticizers reduces the ionic conductivity of the composite anion exchange membrane, further increasing its internal resistance. When applied in a water electrolysis system (specifically, an electrolyzer), this results in a higher voltage value at the same current density in the polarization curve. This voltage value corresponds to the cell voltage of the electrolyzer, meaning the cell voltage increases.

[0194] Compared with Example 2, Example 1 differs in the type of plasticizer used. When the composite anion exchange membrane was applied to the nickel ferrite anode-platinum carbon cathode catalytic system, tests revealed that the hydrogen content in the oxygen on the anode side and the current density in the polarization curve were 1 A / cm². 2 The voltage value and the internal resistance of the composite anion exchange membrane are close.

[0195] Comparing Examples 3, 4, 1, and 5 to 7, it can be seen that as the content of plasticizer in the composite anion exchange membrane increases, when the composite anion exchange membrane contains plasticizer, the application of the composite anion exchange membrane in the nickel ferrite anode-platinum carbon cathode catalytic system shows that the hydrogen content in the oxygen on the anode side decreases, and the current density in the polarization curve is 1 A / cm. 2 As the voltage increases, the internal resistance of the composite anion exchange membrane increases.

[0196] 6. Ultraviolet transmittance test The UV-transmittance test method can be used to characterize the filling effect of the homogeneous layer in the unalkalized composite membrane, as well as the bonding effect between the homogeneous layer and the reinforcing layer (specifically PEEK or PPS) (i.e., the wettability of the resin slurry and the reinforcing layer).

[0197] Test method: a: After fixing the composite membrane onto the hollow base membrane (in a U-shape), fix the base membrane in the cuvette tank; b: The ultraviolet transmittance curve of the composite film was tested in qualitative analysis mode. The transmittance was taken at 720nm, and the results are recorded in Table 5.

[0198] As shown in Table 5, without the addition of plasticizer, the resin slurry and the reinforcing layer have poor bonding, and the overall membrane surface appears frosted and hazy. The UV transmittance is less than 35%. This is because the composite membrane has poor flatness, and because the reinforcing layer (PEEK or PPS) is woven and has a certain pore size, the resin slurry needs to be immersed in the pores (i.e., it needs to completely fill the pores of the reinforcing layer). Without the addition of plasticizer, the bonding between the resin slurry and the reinforcing layer is poor, and some of the resin slurry may float on the surface of the reinforcing layer, resulting in low UV transmittance. After the addition of plasticizer, the filling effect of the resin slurry and the reinforcing layer is more obvious, and the overall membrane surface appears smooth and transparent, with a UV transmittance higher than 35%, indicating that the wettability of the resin slurry and the reinforcing layer is significantly improved.

[0199] Table 5

[0200] Note: The smooth surface is the contact surface between the base film and the first layer of slurry, and the rough surface is the film surface after the second layer of slurry is cast and dried after the reinforcing layer is attached to the first layer of slurry.

[0201] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing a composite anion exchange membrane, characterized in that, include: Anion exchange resin, plasticizer, and solvent are mixed to obtain a blended slurry; The blended slurry is subjected to film-forming treatment on both sides of a porous substrate to obtain a composite membrane; The composite membrane is subjected to ion exchange treatment using an ion exchange solution to obtain a composite anion exchange membrane.

2. The method for preparing the composite anion exchange membrane according to claim 1, characterized in that, The process of mixing anion exchange resin, plasticizer, and solvent to obtain a blended slurry includes: Anion exchange resin is added to a solvent to obtain anion exchange resin slurry; A plasticizer is added to the anion exchange resin slurry to obtain a blended slurry.

3. The method for preparing the composite anion exchange membrane according to claim 2, characterized in that, The solid content of the anion exchange resin slurry is 10wt%~60wt%; and / or, at 25°C, the viscosity of the anion exchange resin slurry is 1000mPa.s~80000mPa.s.

4. The method for preparing the composite anion exchange membrane according to claim 3, characterized in that, The solid content of the anion exchange resin slurry is 15wt%~30wt%; and / or, at 25°C, the viscosity of the anion exchange resin slurry is 4000mPa.s~60000mPa.s.

5. The method for preparing the composite anion exchange membrane according to any one of claims 1 to 4, characterized in that, The step of forming a composite membrane by depositing the blended slurry on both sides of a porous substrate includes: The blended slurry is coated on the surface of the base film to obtain the first wet film layer; A porous substrate is laid on the surface of the first wet film layer facing away from the base film; The first wet film layer is subjected to a first drying treatment; The blended slurry is coated onto the surface of the porous substrate on the side opposite to the first wet film layer to obtain a second wet film layer. The second wet film layer is subjected to a second drying process; The base film is removed to obtain a composite film.

6. The method for preparing the composite anion exchange membrane according to claim 5, characterized in that, The total thickness of the first wet film layer and the second wet film layer is 30μm~1000μm.

7. The method for preparing the composite anion exchange membrane according to any one of claims 1 to 6, characterized in that, In the blended slurry, the content of the plasticizer is 0.5 wt% to 20 wt%; and / or, The plasticizer has a relative molecular mass of 100-500; and / or, The plasticizer includes at least one of the following substances: , , , , , ; and / or, The solvent is an organic solvent, including at least one selected from dimethyl sulfoxide, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and acetonitrile; and / or, The ion exchange solution is an alkaline solution, which is used to alkalize the composite membrane, and the resulting composite anion exchange membrane is a hydroxide-type anion exchange membrane. And / or, The method for preparing the composite anion exchange membrane further includes: filtering the blended slurry with a 2000-6000 mesh filter cloth before the film-forming treatment; and / or, The preparation process of the blended slurry includes: adding plasticizer to anion exchange resin slurry, and physically blending and stirring at 60℃~80℃ to obtain the blended slurry.

8. The method for preparing the composite anion exchange membrane according to any one of claims 1 to 7, characterized in that, The general structural formula of the anion exchange resin is shown in formula (Ⅰ): Equation (Ⅰ); Ar is selected from substituted or unsubstituted aryl groups; R1 and R3 are each independently selected from one of the following: alkyl chain, hydrogen, heteroatom group, and polycyclic ring structure; R2 is selected from alkyl chains and polycyclic ring structures; R4, R5, R6, R7, and R8 are each independently selected from one of hydrogen, alkyl, alkenyl, alkynyl, and aromatic rings; Z - It is an anion; x, y, and z are each any number between 0 and 1, x + y + z = 1, at least one of x, y, and z is not 0, and when x is not 0, at least one of y and z is not 0; n is an integer between 10 and 1,000,000.

9. The method for preparing the composite anion exchange membrane according to claim 8, characterized in that, Z - Selected from OH - Cl - ,Br - HCO3 - CO3 2- NO3 - CF3COO - CH3COO - and R0SO3 - One or more of the following; wherein R0 is an organic group.

10. The method for preparing the composite anion exchange membrane according to claim 9, characterized in that, R0 is selected from one of methyl, ethyl, vinyl, cyclopropyl, trifluoromethyl, phenyl, tolyl, nitrophenyl, and benzyl.

11. The method for preparing the composite anion exchange membrane according to any one of claims 8 to 10, characterized in that, The alkyl chain has 10 or fewer carbon atoms; and / or, The heteroatomic group includes at least one of Br, Cl, F, N, O, and S; and / or, The multi-ring structure includes at least one of ternary rings, quaternary rings, quinary rings, and hexa-rings.

12. The method for preparing the composite anion exchange membrane according to any one of claims 8 to 11, characterized in that, The preparation process of the anion exchange resin includes: The first monomer and the second monomer are polymerized under superacid catalysis to form a multi-component copolymer intermediate, wherein the first monomer includes at least one of aryl monomers and carbonyl monomers, and the second monomer includes at least one of piperidinone monomers and quininecycloketone monomers. The anion exchange resin is obtained by quaternizing the multi-component copolymer intermediate, and the anion exchange resin is a quaternized anion exchange resin.

13. The method for preparing the composite anion exchange membrane according to claim 12, characterized in that, The aryl monomer comprises at least one selected from biphenyl, p-terphenyl, m-terphenyl, p-tetraphenyl, diphenylmethane, 1,3,5-triphenylbenzene, triphenylmethane, 9,10-benzophenanthrene, tetraphenylmethane, triphenylene, 9,9'-diphenylfluorene, 9,9'-spirodifluorene, 9,9'-bifluorene, 9,9'-bicarbazole, 2,2'-bi-9,9'-spirobis[9H-fluorene], 4,4-bis(9-carbazole)biphenyl, and triphenylamine; and / or, The carbonyl monomer includes at least one selected from butanedione, trifluoroacetone, and hydroxyacetone; and / or, The piperidone monomer includes at least one of the following substances: ; and / or, The quinine cyclic ketone monomer includes at least one of the following substances: 。 14. The method for preparing the composite anion exchange membrane according to any one of claims 1 to 13, characterized in that, The porous substrate is a mesh fabric.

15. The method for preparing the composite anion exchange membrane according to claim 14, characterized in that, The material of the mesh fabric includes at least one selected from polyetheretherketone, polyphenylene sulfide, polyphenylene sulfone, polyethylene terephthalate, polypropylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, liquid crystal polymer, and polyethersulfone; and / or, The thickness of the mesh fabric is 5μm~250μm; and / or, The mesh size of the fabric is 20μm~200μm.

16. An electrochemical device, characterized in that, The composite anion exchange membrane prepared by the method described in any one of claims 1 to 15 includes the composite anion exchange membrane prepared by the method described in any one of claims 1 to 15.

17. The electrochemical device according to claim 16, characterized in that, The electrochemical device includes at least one of a battery and a water electrolysis hydrogen production device.

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