An enhanced anion exchange membrane based on a microporous framework and an integrated membrane electrode

Abstract

This invention discloses an enhanced anion exchange membrane and an integrated membrane electrode based on a microporous framework. The enhanced anion exchange membrane includes a microporous framework layer and an anion exchange layer laminated to one side of the microporous framework layer. The anion exchange layer includes anion conductor material. The anion conductor material fills some of the pores in the microporous framework layer to form an anion exchange region on the side near the anion exchange layer. In the anion exchange region, the anion conductor material forms a gradually decreasing concentration gradient from the side near the anion exchange layer inward. Based on a durable microporous framework reinforcement layer, this invention, through gradient filling technology and structural optimization design, prepares a high-performance and stable durable enhanced anion exchange membrane and an integrated membrane electrode, solving the technical problems urgently needing to be addressed in fuel cells and water electrolysis for hydrogen production, such as the contradiction between the mechanical strength and ion conductivity of membrane materials, high catalyst interfacial contact resistance, and easy detachment.

Description

Technical Field

[0001] The invention relates to the field of new energy technology, particularly to the field of ion exchange membrane material manufacturing in fuel cells and water electrolysis hydrogen production devices, and especially to an enhanced anion exchange membrane and an integrated membrane electrode based on a microporous framework, as well as their preparation methods. Background Technology

[0002] Hydrogen energy is a clean and renewable energy source with outstanding advantages such as high energy density and zero pollution. Its use and development are among the most feasible ways to solve energy and environmental problems. Currently, the mainstream hydrogen production routes include fossil fuel-based chemical hydrogen production, biomass hydrogen production, and water electrolysis hydrogen production. Only hydrogen produced by electrolyzing water using green electricity from wind and solar power is truly green. The power output of wind and solar power is unstable; during peak periods, not all electricity can be absorbed by the grid, resulting in curtailment. Electrochemical hydrogen production technology has good compatibility with wind and solar power, and combining water electrolysis hydrogen production technology with green electricity has gradually become a major method for the large-scale comprehensive development and utilization of renewable energy in recent years. Green hydrogen is not only an energy source but also a basic chemical raw material. Converting green electricity into green hydrogen (P2G) through water electrolysis hydrogen production devices (electrolyzers) not only achieves large-scale, long-term energy storage of green electricity but also drives the development of green chemicals, representing a much larger market. There are four main types of electrolyzers: ALKWE, PEMWE, AEMWE, and SOEC. ALKWE is a mature technology that operates under strong alkaline and low-pressure conditions, with low manufacturing costs, but suffers from low electrolysis efficiency, poor power response, and high maintenance costs. PEMWE operates under acidic and high-pressure conditions, offering high current density and electrolysis efficiency, and fast power response, but it relies on platinum group metal (PGM) catalysts, resulting in high costs and limiting its large-scale application due to PGM natural resources. AEMWE electrolyzers are similar to ALKWE electrolyzers, using weakly alkaline electrolytes and non-platinum catalysts, resulting in low costs. Like PEMWE electrolyzers, it employs a polymer electrolyte membrane structure with zero-gap membrane electrodes, thus sharing the characteristics of small size, maintenance-free operation, and fast power response. Furthermore, it boasts higher electrolysis efficiency than PEMWE and is currently a hot research topic for water electrolysis hydrogen production devices, considered a major direction for future electrolyzer development. Although SOEC has a higher electrolysis efficiency than AEMWE, it must operate at high temperatures, has high material costs, and limited application scenarios, making it difficult to enter commercial applications.

[0003] The main technical challenges currently facing AEMWE technology are: 1. The chemical stability of the fixed quaternary ammonium cations in anion exchange membranes (AEMs) is easily decomposed and eliminated, leading to a short service life of the AEM membrane; 2. Compared with proton exchange membranes (PEMs), AEMs have higher ion exchange capacity (IEC), higher water absorption and swelling rate, poorer dimensional stability, and lower wet membrane strength. These two points seriously affect the operational stability and electrochemical performance of AEMWEs.

[0004] To address the issues caused by high swelling rates, nonwoven fabrics, woven meshes, or porous membranes are commonly used as reinforcing layers in anion exchange membranes. These built-in reinforcing layers are typically hydrophobic materials that do not swell in aqueous solutions, thus maintaining their strength when dry. Furthermore, they spatially separate the AEM (anion exchange membrane material), dispersing the swelling stress after AEM water absorption and preventing severe deflection and flatness due to uneven expansion stress. However, the reinforcing layer occupies space, reducing ion transport channels and increasing membrane resistance. Moreover, for reinforcing layer membranes with microporous structures, simple surface AEM solution coating processes cannot completely fill the micropores, further reducing the ionic conductivity of the composite membrane and causing the AEM to detach from the reinforcing layer due to weak bonding. Therefore, for the preparation of reinforced AEM membranes using porous membranes, the interfacial wetting problem between the AEM solution and the porous membrane must be resolved.

[0005] Invention CN119529349A discloses a porous substrate-reinforced anion exchange membrane, which is obtained by uniformly mixing a polyarylene alkylene cationic polymer solution with a C1-C10 alcohol solvent, coating the mixture onto both sides of a porous substrate, and then removing the solvent. This invention eliminates the need for pretreatment of the porous substrate, achieving good wetting of the cationic polymer solution onto the porous substrate, thus obtaining a sandwich-like porous substrate-reinforced anion exchange membrane. Although this membrane exhibits outstanding anti-swelling properties, excellent mechanical properties, and good electrochemical performance, this method of coating both sides of the porous reinforcing layer with AEM solution results in weak adhesion between the catalyst and AEM during catalyst layer coating. This makes the catalyst prone to detachment due to gas-liquid erosion during subsequent use of the membrane electrode, leading to premature degradation of electrode performance. To address this issue, invention CN119506921A discloses a structural design for an AEM electrolyzer, which includes a cathode catalytic substrate and an anode catalytic substrate. These substrates provide a certain surface pressure to the cathode and anode catalytic layers, allowing the catalytic layers to be uniformly adhered to both sides of this enhanced anion exchange membrane. However, this membrane electrode structure is relatively complex, increasing space requirements and manufacturing costs. Furthermore, the planar adhesion cannot guarantee a stable bond between the rough catalyst localization and the AEM membrane.

[0006] As a reinforcing layer, porous membranes have a significant advantage over nonwoven fabrics and woven meshes in terms of tensile strength. Designing and fabricating high-performance, stable, and durable reinforced anion exchange membranes and membrane electrodes based on a microporous framework reinforcing layer resistant to alkali water swelling, resolving the contradiction between low-humidity membrane tensile strength, large swelling deflection, and high ion conductivity of AEM membranes, and simultaneously addressing issues such as high catalyst / AEM interface contact resistance and easy catalyst detachment, are crucial technical challenges that urgently need to be overcome in the fabrication of fuel cells and water electrolysis hydrogen production electrolyzers. Summary of the Invention

[0007] To address the shortcomings of the existing technologies, this invention provides an enhanced anion exchange membrane based on a microporous framework and its preparation method, as well as an integrated membrane electrode and its preparation method. Through gradient filling technology and structural optimization, it solves the problems of the contradiction between the mechanical strength and ion conductivity of membrane materials, high contact resistance at the catalyst / AEM interface, and easy catalyst detachment in the existing technologies.

[0008] In a first aspect, the present invention provides an enhanced anion exchange membrane based on a microporous framework, comprising a microporous framework layer and an anion exchange layer laminated on one side of the microporous framework layer.

[0009] The anion exchange layer includes anion-conducting materials;

[0010] The anion conductor material fills some of the pores in the microporous framework layer to form an anion exchange region on the side near the anion exchange layer;

[0011] In the anion exchange region, the anion conductor material forms a decreasing concentration gradient from the side closest to the anion exchange layer inwards.

[0012] This invention creates a concentration gradient along the thickness of the microporous framework layer by repeatedly permeating the anion-conducting resin casting solution. This allows for the gradual accumulation of anion-conducting resin material on the coating surface and within the micropores, increasing the number of ion transport channels and the conductivity of the ion exchange membrane. Furthermore, due to the gradually decreasing concentration gradient, the microporous framework layer, on the side furthest from the anion exchange layer, contains almost no or only a small amount of anion-conducting polymer, providing micropore anchoring points for the subsequent deposition of other materials in applications.

[0013] Furthermore, the microporous framework layer includes at least one of polyethylene membrane, polypropylene membrane, polyamide membrane, and polytetrafluoroethylene membrane;

[0014] The thickness of the microporous framework layer is 5-60 μm, the porosity is 40-80%, and the pore size is 0.05-2 μm.

[0015] Furthermore, the microporous framework layer undergoes hydrophilic modification treatment, including the following steps:

[0016] A hydrophilic modification solution is prepared, wherein the hydrophilic modification solution contains one or more of ethylene-vinyl alcohol copolymer and dopamine;

[0017] The microporous framework is immersed in the hydrophilic modification solution and then subjected to ultrasonic modification.

[0018] Furthermore, the ultrasonic treatment is preferably performed for 10-30 minutes, after which excess solution is removed from the surface and dried to obtain a surface-hydrophilic microporous skeleton membrane.

[0019] Furthermore, the hydrophilic modified solution is obtained by dissolving one or more of ethylene-vinyl alcohol copolymer and dopamine at a total concentration of 0.5-2.5 g / L in an alcohol-water solution. The alcohol-water solution is obtained by mixing one or more of n-propanol, isopropanol, ethanol, and methanol with deionized water in a certain proportion. The preferred volume ratio of alcohol to water in the alcohol-water solution is (1-5):(5-9).

[0020] Furthermore, the anion conductor material comprises arylpiperidine resins. Specifically, the anion conductor material is a resin material with anion exchange capacity formed by superacid-catalyzed polymerization of aryl polymers as the main chain and piperidine, imidazole, spirocyclic compounds, aliphatic ammonium compounds, quaternary phosphine, guanidine salts, and metal cations as cationic functional groups.

[0021] The anionic conductor material of this invention uses arylpiperidine resins as its core system. Its molecular structure consists of a rigid aromatic backbone and synergistic functional groups of piperidine, imidazole, or spirocyclic quaternary ammonium cationic groups. The material is synthesized using metal-free superacid-catalyzed polymerization technology. Using Brønsted superacids such as trifluoromethanesulfonic acid (TFSA) as proton sources, the aromatic monomers undergo stepwise polycondensation via Friedel-Crafts alkylation in a room-temperature solution system, forming an "ether-free" aromatic polymer network with both high alkali resistance and ion conductivity. During the reaction, the carbonyl groups of ketone monomers are protonated in the superacid environment to form highly reactive carbocation intermediates, driving directional coupling with polycyclic aromatic hydrocarbons such as biphenyl and terphenyl, ultimately constructing a topologically controllable three-dimensional cross-linked structure. Commonly used monomers include two main categories: ketone monomers and aromatic hydrocarbons. Common aromatic hydrocarbons include biphenyl, terphenyl with different conformations, and p-tetraphenyl, etc. Ketone monomers include aldehydes and ketones, nitriles, fluorinated ketone monomers, and 1,2-dicarbonyl (hereinafter referred to as diketone monomers), etc.

[0022] Furthermore, based on the total thickness L0 of the microporous framework layer: the thickness L1 of the anion exchange layer satisfies: 2%×L0≤L1≤20%×L0;

[0023] Starting from the side closest to the anion exchange layer, the thickness L2 of the microporous framework layer filled by the anion conductor material satisfies: 20%×L0≤L2<100%×L0.

[0024] Secondly, the present invention provides a method for preparing an enhanced anion exchange membrane, comprising the following steps:

[0025] Step 1: Perform hydrophilic modification treatment on the microporous framework layer;

[0026] Step 2: Prepare casting solutions C1 and C2 containing anionic conductor materials, with the concentration of casting solution C1 being lower than that of casting solution C2;

[0027] Step 3: Apply casting solution C1 to one side of the microporous framework layer, and repeat the application several times after drying. The anionic conductor material fills part of the pores in the microporous framework layer.

[0028] Step 4: Apply casting solution C2 to the side surface and vacuum dry to obtain an anion exchange layer laminated on one side of the microporous framework layer, and an anion exchange region near the anion exchange layer.

[0029] In this invention, the anion-exchange region exhibits a decreasing concentration gradient of anion conductor material along its thickness. Due to differences in wetting path and resistance along the thickness direction, a certain concentration gradient can be formed after multiple applications of the casting solution. Furthermore, to controllably form a concentration gradient, the same concentration of casting solution can be repeatedly applied multiple times, with the amount applied each time varying to regulate the concentration gradient; alternatively, different drying rates can be used to control the degree of wetting by the casting solution; or different concentrations of casting solution can be applied sequentially to form a concentration gradient with controllable gradient variation. Vacuum-assisted wetting and filling can also be used to guide the formation of concentration gradients in different regions.

[0030] The casting solution is prepared by dissolving anionic conductor material in one or more polar solvents, namely dimethyl sulfoxide, N-methylpyrrolidone, and N,N-dimethylimide, at the required mass fraction and mixing them uniformly. Generally, the mass concentrations of casting solutions C1 and C2 are 10-30 wt%, with the concentration of casting solution C1 being lower than that of casting solution C2. For example, the concentration of casting solution C1 is controlled at 10-25 wt%, and the concentration of casting solution C2 is controlled at 20-30 wt%. The low-concentration casting solution C1 is repeatedly applied to one side of the microporous framework layer and dried, allowing the anionic conductor material in casting solution C1 to gradually fill the pores of the microporous framework layer. After repeated layering and filling, the pores near the anion exchange layer gradually tend to be completely filled, forming a gradually decreasing concentration gradient from that side inwards.

[0031] Furthermore, in step two, the casting solution C1 is configured to contain casting solutions C with progressively increasing concentrations. 1-1 Casting solution C 1-2 ... and casting solution C 1-n n is a natural number greater than 1;

[0032] In step three, casting solution C 1-1 Casting solution C 1-2 ... and casting solution C 1-n The material is applied and dried sequentially, causing the anionic conductor material to fill some of the pores in the microporous framework layer and forming a decreasing concentration gradient from the outside to the inside.

[0033] For example, casting solution C1 can be divided into three casting solutions with progressively increasing concentrations (i.e., taking n=3 as an example), and applied in order from low to high concentration. Casting solution C... 1-1 The concentration can be selected as 10-15 wt%, casting solution C 1-2 The concentration can be selected as 15-20wt%, casting solution C 1-3 The concentration can be selected as 20-25wt%.

[0034] More preferably, 1. Casting solution C 1-1 The concentration can be selected as 10wt%, casting solution C 1-2 The concentration can be selected as 15wt%, casting solution C 1-3 The concentration can be selected as 20wt%.

[0035] The initial low-concentration casting solution, due to its good fluidity and numerous pores in the microporous framework, is easy to fill and can quickly fill a group of pores over a considerable distance. When filling with the subsequent high-concentration casting solution, due to the influence of fluidity and steric hindrance, the furthest point reached will be less than that reached by the initial low-concentration solution within the same filling time. Therefore, the above filling method can easily and quickly form a gradually decreasing concentration gradient in the microporous framework layer. The selection of the above concentration range is also based on the thickness, porosity, and pore size of the microporous framework layer, as well as the viscosity of the casting solution. When the casting solution concentration is too low, a large amount of the casting solution will penetrate the microporous framework layer, making it difficult to leave unfilled pores on the other side. When the casting solution concentration is too high, it is difficult to effectively penetrate and fill the pores within the microporous framework, resulting in a decrease in the number of ion transport channels and conductivity.

[0036] Thirdly, the present invention provides an integrated membrane electrode based on the enhanced anion exchange membrane, which sequentially comprises an anode catalyst layer, an enhanced anion exchange membrane, and a cathode catalyst layer;

[0037] The anode catalyst layer is connected to the anion exchange layer;

[0038] The cathode catalyst layer is connected to the other side of the microporous framework layer opposite to the anion exchange layer.

[0039] The pores of the microporous framework layer near the cathode catalyst layer are at least partially filled with cathode catalyst to form a cathode catalytic region.

[0040] Furthermore, the integrated membrane electrode satisfies at least one of the following characteristics:

[0041] 1) The anode catalyst layer consists of layered double metal hydroxide (LDH) catalyst with a loading of 2-20 mg / cm³. 2 Preferred concentration: 5-18 mg / cm³ 2 More preferably 8-15 mg / cm 2 ;

[0042] 2) The cathode catalyst layer includes a Pt / C catalyst with a loading of 0.2-1.0 mg / cm³. 2 The preferred concentration is 0.3-0.8 mg / cm³. 2 .

[0043] This invention effectively utilizes the pores of the microporous framework layer to not only create an anion conductor material concentration gradient in the anion exchange region of the enhanced anion exchange membrane, but also forms a cathode catalytic region filled with cathode catalyst in at least a portion of the remaining unfilled pores relative to the anion exchange region. The formation of this anion exchange region and cathode catalytic region is particularly advantageous for the application of integrated membrane electrodes in fuel cells and water electrolysis for hydrogen production: on the one hand, the pore filling rate within the microporous framework layer is significantly improved, providing more three-dimensional space to help the catalyst form a three-dimensional structure, improving catalytic efficiency and resolving the contradiction between the mechanical strength and ion conductivity of the membrane material; on the other hand, the pores of the microporous framework layer provide reliable anchoring points for the long-term stable adhesion of the laminated layers on both sides, especially the catalyst layer. The chemical adhesion force enhances the mechanical anchoring effect, effectively reducing the risk of catalyst failure due to gas-liquid erosion during subsequent use, thus solving defects such as high catalyst interfacial contact resistance and easy detachment. Compared to the existing sandwich structure with symmetrical filling on both sides of a single AEM material reinforcement layer, this invention makes full use of the three-dimensional pore network of the microporous skeleton layer to form a dual-fill structure with an insert-type mechanical anchoring micromorphology. This not only improves ion transport performance but also extends the service life of the ion exchange membrane and reduces material costs, making it of great promotional value.

[0044] Fourthly, the present invention also provides a method for preparing an integrated membrane electrode, comprising the following steps:

[0045] S1: Prepare the enhanced anion exchange membrane;

[0046] S2: Prepare the anode catalyst slurry and cathode catalyst slurry;

[0047] S3: Apply the cathode catalyst slurry to the side of the microporous framework layer opposite to the anion exchange layer, and fill part of the cathode catalyst into the pores of the microporous framework layer near the cathode catalyst layer to form the cathode catalyst layer and the cathode catalytic region.

[0048] S4: The anode catalyst layer is formed on the anion exchange layer by means of anode catalyst slurry.

[0049] Furthermore, the cathode catalyst slurry is prepared by mixing 30-60% Pt / C catalyst, ionomer, ethanol, and water in a mass ratio of 0.1-5:5-10:30-50:10-20. The cathode catalyst slurry is applied by a spraying process, wherein the spraying process is selected from ultrasonic spraying, electrostatic spraying, and manual spraying.

[0050] Furthermore, the anode catalyst is an iron-cobalt-nickel double hydroxide obtained by hydrothermal reaction of an iron-cobalt-nickel precursor. The anode catalyst slurry is prepared by mixing LDH catalyst, binder, dispersant, and organic solvent in a mass ratio of 20-50:5-15:5-8:40-60. The binder comprises a mixed solution containing 5-15 wt% anionic ionomer and 2-6 wt% polytetrafluoroethylene; the dispersant comprises one or more of methanol, n-propanol, isopropanol, and ethanol; and the organic solvent comprises one or more of N-methylpyrrolidone, N,N-dimethylimide, and dimethyl sulfoxide.

[0051] Furthermore, step S4 involves forming the anode catalyst layer using a thermal transfer method, including:

[0052] (1) The anode catalyst slurry is coated onto the release film and dried to obtain the anode catalyst heat transfer film;

[0053] (2) Cover the anion exchange layer of the enhanced anion exchange membrane with the thermal transfer sheet of the anode catalyst; cover the cathode catalyst layer on the other side with a blank release film;

[0054] (3) The anode catalyst layer is thermally transferred to the surface of the anion exchange layer of the enhanced anion exchange membrane under certain temperature and pressure on a hot press, and finally an integrated membrane electrode with a "sandwich" structure with a cathode catalyst layer and an anode catalyst layer on both sides is obtained.

[0055] Furthermore, the anode catalyst slurry is applied to the release film via a slit coating process, with a coating thickness of 20-100 μm. The release film is selected from PTFE film or PET film, with a thickness of 50-200 μm.

[0056] Furthermore, in step (3), the hot pressing temperature of the hot press is 60-120℃, the hot pressing pressure is 2-10MPa, and the time is 1-3 hours.

[0057] The beneficial effects of the present invention include at least the following:

[0058] (1) The present invention forms a concentration gradient along the thickness direction of the microporous framework layer by multiple permeation of the anion conductor resin casting solution. This allows the anion conductor resin material to gradually accumulate on the coating surface and in the internal micropores, thereby increasing the number of ion transport channels and the conductivity of the ion exchange membrane. Furthermore, the unfilled pore areas in the microporous framework layer provide three-dimensional filling space and micropore anchoring points for the subsequent cathode catalyst, which is beneficial for forming a stable and highly active catalytic interface.

[0059] (2) The present invention utilizes the three-dimensional structure of the microporous skeleton layer to form a dual-material filling structure with an insert-type mechanical anchoring micromorphology through anionic conductor materials and catalyst materials, which significantly improves the mechanical strength, anti-swelling performance and ion conductivity of the integrated membrane electrode, and the overall performance exceeds that of the homogeneous membrane base material and single-material sandwich structure membrane of the prior art.

[0060] (3) The adhesion and stability of the catalyst layer in the integrated membrane electrode of the present invention are significantly improved. By filling the three-dimensional pores of the microporous framework layer with cathode catalyst, a cathode catalytic region integrated with the cathode catalyst layer is formed. The chemical interlayer bonding force and the insert-type mechanical anchoring force are fully utilized, which enhances the bonding effect between the catalyst layer and the microporous framework layer, reduces the risk of catalyst loss due to gas-liquid scouring, and extends the service life of the ion exchange membrane while improving ion transport and other performance, and reduces material costs. It has great promotional value. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the integrated membrane electrode based on the enhanced anion exchange membrane of the present invention;

[0062] Figure 2 Electron microscope image of a microporous framework layer made of polypropylene;

[0063] Figure 3 This is a cross-sectional electron microscope image of the enhanced anion exchange membrane based on a microporous framework according to the present invention.

[0064] Figure 4 A cross-sectional electron microscope image of the enhanced anion exchange membrane in Comparative Example 2, which is coated on both sides to form an anion exchange layer.

[0065] Figure 5 The stress-strain curves of each sample in Example 1, Comparative Example 1, and Comparative Example 2 are shown below.

[0066] Figure 6 An electron microscope image of the integrated membrane electrode of Application Example 1 of the present invention;

[0067] Figure 7 An electron microscope image of the surface of the anode catalyst layer in the integrated membrane electrode of Application Example 1 of the present invention.

[0068] Explanation of reference numerals in the attached figures: 1-microporous framework layer, 2-anion exchange layer, 3-anodic catalyst layer, 4-cathode catalyst layer, 11-anion exchange region, 12-cathode catalytic region. Detailed Implementation

[0069] To better understand the above technical solutions, a detailed description of the solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0070] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0071] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0072] An enhanced anion exchange membrane based on a microporous framework, see [link to relevant documentation]. Figure 1-3 ,include:

[0073] (1) Microporous framework layer 1 includes at least one of polyethylene membrane, polypropylene membrane, polyamide membrane, and polytetrafluoroethylene membrane; preferably, the microporous framework layer is hydrophilically modified.

[0074] The microporous framework layer 1 includes anion exchange regions 11 and blank regions. The anion exchange regions 11 are formed on the side near the anion exchange layer 2 by filling part of the pores of the microporous framework layer 1 with anion conductor material, and the anion conductor material forms a decreasing concentration gradient from the side near the anion exchange layer 2 inward. The blank regions, relative to the anion exchange regions 11, are unfilled microporous framework pores, mainly distributed on the other side of the microporous framework layer 1 away from the anion exchange layer 2.

[0075] (2) Anion exchange layer 2, laminated on one side of the microporous framework layer 1; the anion exchange layer 2 includes anion conductor material; the anion exchange layer 2 and the anion conductor material in the anion exchange region 11 preferably form an integral structure. The anion conductor material includes arylpiperidine resins. Specifically, the anion conductor material is a resin material with anion exchange capacity formed by superacid catalytic polymerization with aryl polymers as the main chain and piperidine, imidazole, spirocyclic compounds, etc. as cationic functional groups.

[0076] Regarding dimensions, see Figure 2 The thickness L0 of the microporous framework layer 1 is 5-60 μm, the porosity is 40-80%, and the pore size is 0.05-2 μm. Based on the total thickness L0 of the microporous framework layer 1:

[0077] The thickness L1 of the anion exchange layer 2 satisfies: 2%×L0≤L1≤20%×L0;

[0078] Starting from the side closest to the anion exchange layer 2, the thickness L2 of the microporous framework layer 1 filled with the anion conductor material satisfies: 20%×L0≤L2<100%×L0.

[0079] The method for preparing the enhanced anion exchange membrane includes the following steps:

[0080] Step 1: Perform hydrophilic modification treatment on microporous framework layer 1:

[0081] (1) Prepare a hydrophilic modification solution by dissolving one or more of ethylene-vinyl alcohol copolymer and dopamine in an alcohol-water solution at a total concentration of 0.5-2.5 g / L. The alcohol-water solution is obtained by mixing one or more of n-propanol, isopropanol, ethanol, and methanol with deionized water in a certain proportion. The preferred mixing volume ratio of alcohol and water in the alcohol-water solution is (1-5):(5-9).

[0082] (2) Immerse the microporous skeleton in the hydrophilic modification solution, ultrasonically modify it for 10-30 min, remove it to remove excess solution from the surface, and dry it to obtain a microporous skeleton membrane with hydrophilic surface treatment.

[0083] Step 2: Prepare casting solutions C1 and C2 containing anionic conductor materials:

[0084] The casting solution is prepared by dissolving anionic conductor material in one or more of the polar solvents dimethyl sulfoxide, N-methylpyrrolidone, and N,N-dimethylimide at the required mass fraction, and then mixing them uniformly. The mass concentration of the casting solution is 10-30 wt%, and the concentration of casting solution C1 is lower than that of casting solution C2. Preferably, the concentration of casting solution C1 is controlled at 10-25 wt%, and the concentration of casting solution C2 is controlled at 20-30 wt%.

[0085] Preferably, the casting solution C1 is configured to contain casting solutions C with progressively increasing concentrations. 1-1 Casting solution C 1-2 ... and casting solution C 1-n n is a natural number greater than 1; for example, casting solution C1 is divided into 3 casting solutions with progressively increasing concentrations (i.e., taking n=3 as an example), casting solution C 1-1 The concentration can be selected as 10-15 wt%, casting solution C 1-2 The concentration can be selected as 15-20wt%, casting solution C 1-3 The concentration can be selected as 20-25 wt%;

[0086] Step 3: Apply casting solution C1 to one side of the microporous framework layer 1, and repeat the application several times after drying. The anionic conductor material fills part of the pores in the microporous framework layer 1. Preferably, casting solution C1... 1-1 Casting solution C 1-2 ... and casting solution C 1-n The material is applied and dried sequentially, causing the anionic conductor material to fill part of the pores in the microporous framework layer 1 and forming a decreasing concentration gradient from the outside to the inside.

[0087] Step 4: Apply casting solution C2 to the side surface and vacuum dry to obtain an anion exchange layer 2 laminated on one side of the microporous framework layer 1, and an anion exchange region 11 near the anion exchange layer 2.

[0088] See Figure 1 6-7, An integrated membrane electrode based on the enhanced anion exchange membrane, comprising, in sequence:

[0089] (1) Anode catalyst layer 3, connected to anion exchange layer 2, includes layered double metal hydroxide (LDH) catalyst with a loading of 2-20 mg / cm³. 2 ;

[0090] (2) An enhanced anion exchange membrane, comprising a microporous framework layer 1 and an anion exchange layer 2; at least part of the pores of the microporous framework layer 1 on the side near the cathode catalyst layer 4 are filled with cathode catalyst to form a cathode catalytic region 12.

[0091] (3) Cathode catalyst layer 4, comprising Pt / C catalyst with a loading of 0.2-1.0 mg / cm³. 2 It is connected to the other side of the microporous framework layer 1 opposite to the anion exchange layer 2, and forms an integral structure with the cathode catalyst in the cathode catalytic region 12.

[0092] The method for preparing the integrated membrane electrode includes the following steps:

[0093] S1: The preparation of the enhanced anion exchange membrane is as described above and will not be repeated here;

[0094] S2: Prepare the anode catalyst slurry and cathode catalyst slurry:

[0095] The cathode catalyst slurry is prepared by mixing 30-60% Pt / C catalyst, ionomer, ethanol, and water in a mass ratio of 0.1-5:5-10:30-50:10-20.

[0096] The ionomer is selected from at least one of poly(arylpiperidine) polymers, polybenzimidazole polymers, polyfluorene polymers, and polyolefin polymers containing polyethylene, polypropylene, and polybutene.

[0097] The anode catalyst is an iron-cobalt-nickel double hydroxide obtained by hydrothermal reaction of an iron-cobalt-nickel precursor. The anode catalyst slurry is prepared by mixing LDH catalyst, binder, dispersant, and organic solvent in a mass ratio of 20-50:5-15:5-8:40-60; the binder includes a mixed solution containing 5-15 wt% anionic ionomer and 2-6 wt% polytetrafluoroethylene; the dispersant includes one or more of methanol, n-propanol, isopropanol, and ethanol; the organic solvent includes one or more of N-methylpyrrolidone, N,N-dimethylimide, and dimethyl sulfoxide.

[0098] S3: Apply the cathode catalyst slurry to the side of the microporous framework layer opposite to the anion exchange layer, and fill part of the cathode catalyst into the pores of the microporous framework layer near the cathode catalyst layer to form the cathode catalyst layer and the cathode catalytic region; the cathode catalyst slurry is applied by a spraying process, which is selected from ultrasonic spraying, electrostatic spraying and manual spraying.

[0099] S4: The anode catalyst layer is formed on the anion exchange layer using an anode catalyst slurry, preferably by thermal transfer, including:

[0100] (1) The anode catalyst slurry is coated onto the release film and dried to obtain the anode catalyst heat transfer sheet; the coating thickness is 20-100μm, and the release film is selected from PTFE film or PET film with a thickness of 50-200μm;

[0101] (2) Cover the anion exchange layer of the enhanced anion exchange membrane with the thermal transfer sheet of the anode catalyst; cover the cathode catalyst layer on the other side with a blank release film;

[0102] (3) The anode catalyst layer is thermally transferred to the surface of the anion exchange layer of the enhanced anion exchange membrane by applying a certain temperature and pressure on a hot press, for example, the hot pressing temperature is 60-120℃, the hot pressing pressure is 2-10MPa, and the time is 1-3 hours, so as to obtain an integrated membrane electrode with a "sandwich" structure with a cathode catalyst layer and an anode catalyst layer on both sides respectively.

[0103] Example 1

[0104] The enhanced anion exchange membrane of this embodiment includes a microporous framework layer 1 and anion exchange layer 2. The microporous framework layer 1 is made of polypropylene porous membrane with a thickness of about 20 μm, a porosity of 50 ± 10%, and a pore size of 0.05-2 μm. The anion exchange layer 2 has a thickness of about 1.5 μm, and the maximum thickness of the anion exchange region 11 formed is about 14 μm.

[0105] The enhanced anion exchange membrane of this embodiment is prepared by the following steps:

[0106] Step 1: Immerse the polypropylene microporous skeleton membrane in a 0.5 g / L ethylene-vinyl alcohol copolymer ethanol aqueous solution (ethanol and water volume ratio 5:5), sonicate for 30 min, then remove it, remove excess solution from the surface, and dry it.

[0107] Step 2: Dissolve 1g of arylpiperidine resin in 10mL of dimethyl sulfoxide solvent to form a 15wt% casting solution C1. Dissolve 3g of arylpiperidine resin in 10mL of dimethyl sulfoxide solvent to form a 30wt% casting solution C2.

[0108] Step 3: Secure the hydrophilic-modified polypropylene microporous framework layer taut using a membrane frame. Apply a 15wt% concentration of arylpiperidine resin casting solution C1 evenly to the first surface of the hydrophilic microporous framework layer using a brush. After drying, repeat the brushing process 5 times. Finally, pour a 30wt% concentration of arylpiperidine resin casting solution C2 evenly onto the first surface to form a coating approximately 20μm thick. Let it stand for 10 minutes, then scrape off any excess casting solution from the first surface and dry it in a vacuum drying oven. The final result is an enhanced anion exchange membrane with only one side of the first surface of the microporous framework layer 1 coated with anion exchange layer 2 and containing anion exchange regions 11. See [link to relevant documentation]. Figure 3 .

[0109] Example 2

[0110] The difference between the enhanced anion exchange membrane in this embodiment and that in Embodiment 1 is that the thickness of the microporous framework layer 1 is about 60 μm, the porosity is 50 ± 10%, and the pore size is between 0.05 and 2 μm; the thickness of the anion exchange layer 2 is about 2 μm, and the maximum thickness of the formed anion exchange region 11 is about 40 μm.

[0111] Example 3

[0112] The difference between the enhanced anion exchange membrane in this embodiment and that in Embodiment 1 is that the thickness of the microporous framework layer 1 is about 10 μm, the porosity is 40 ± 10%, and the pore size is between 0.05 and 1 μm; the thickness of the anion exchange layer 2 is about 1 μm, and the maximum thickness of the formed anion exchange region 11 is about 7 μm.

[0113] Example 4

[0114] The difference between Example 4 and Example 1 is that the casting solution C1 is divided into three types and coated sequentially, including casting solution C... 1-1 Casting solution C 1-2 and casting solution C 1-3 The maximum thickness of the formed anion exchange region is approximately 16 μm. The enhanced anion exchange membrane of this embodiment is prepared through the following steps:

[0115] Step 1: Perform hydrophilic modification treatment on the microporous framework layer, as above;

[0116] Step 2: Prepare casting solution C separately 1-1 Casting solution C 1-2 Casting solution C 1-3 And 30 wt% casting solution C2, wherein casting solution C 1-1 Concentration 10wt%, casting solution C 1-2 The concentration of the casting solution is 15 wt%, and the concentration of the casting solution is C. 1-3 The concentration was 20 wt%.

[0117] Step 3: Secure the hydrophilic-modified polypropylene microporous framework layer taut using a membrane frame. Apply a layer of casting solution C evenly to the first surface of the hydrophilic microporous framework layer using a brush. 1-1 After drying, a layer of casting solution C is evenly brushed on. 1-2 After drying, a layer of casting solution C is evenly brushed on. 1-3 After drying, a 30wt% concentration of arylpiperidine resin casting solution C2 is poured and spread evenly on the first surface to form a coating of about 20μm thickness. After standing for 10 minutes, excess casting solution on the first surface is scraped off and the membrane is placed in a vacuum drying oven to dry. Finally, an enhanced anion exchange membrane with an anion exchange layer coated on one side of the first surface and having anion exchange regions is obtained.

[0118] Comparative Example 1

[0119] 1.5 g of arylpiperidine resin was dissolved in 10 mL of dimethyl sulfoxide to form a 15 wt% casting solution. The casting solution was poured onto a 15 × 15 cm glass slide and allowed to stand for 30 minutes to allow it to self-level and fully cover the entire glass slide, forming a coating with a thickness of approximately 40 μm. The coating was dried at 65 °C for 6 hours, and then dried under vacuum at 80 °C for 2 hours to obtain a homogeneous anion exchange membrane.

[0120] Comparative Example 2

[0121] Comparative Example 2 uses the same microporous framework layer 1 as Example 1, and its anion exchange membrane is prepared through the following steps:

[0122] (1) Immerse the polypropylene microporous skeleton membrane in 0.5 g / L ethylene-vinyl alcohol copolymer ethanol aqueous solution (ethanol and water volume ratio 5:5), sonicate for 30 min, then take it out, remove excess solution from the surface, and dry.

[0123] (2) The hydrophilically modified polypropylene microporous framework membrane was immersed in a 15wt% arylpiperidine resin casting solution C1 and ultrasonically treated for 30 min. After drying, the above steps were repeated 5 times. The membrane after the above treatment was fixed with a membrane frame, and a 30wt% arylpiperidine resin casting solution C2 was coated on its first surface to form a 20μm thick coating. It was then placed in a vacuum drying oven to dry. Subsequently, a 30wt% arylpiperidine resin casting solution C2 was also coated on the second surface to form a 20μm thick coating. After drying, a double-sided anion exchange membrane with anion exchange layers was finally obtained. See [link to relevant documentation]. Figure 4 .

[0124] Test Standards

[0125] The samples obtained from Examples 1-4 and Comparative Examples 1 and 2 were tested according to the following standards:

[0126] 1. Tensile strength: The test method is based on ASTM D638-14 standard. Dumbbell-shaped alkaline anion exchange membranes are cut and tested using a tensile testing machine.

[0127] 2. Elongation at break: The elongation at break was tested using an Instron 6800 universal tensile testing machine.

[0128] 3. Dimensional change rate at 80℃: A 30mm × 40mm alkaline anion exchange membrane was cut, immersed in 1M KOH solution at 80℃, and the length expansion rate was calculated based on the length increase after 24 hours.

[0129] 4. Ionic Conductivity at 80°C: The ionic conductivity of the membrane was obtained by measuring the electrochemical impedance spectroscopy (EIS) of the membrane at 80°C. Specifically, the test sample was cut into a circle with a diameter of 10 cm and clamped in a homemade laboratory apparatus with platinum wire as electrodes (four-probe electrodes). The humidity in the test cell was controlled using nitrogen gas containing water vapor. The resistance value obtained from the Nyquist plot was used to calculate the ionic conductivity of the membrane. The ionic conductivity of each membrane was defined using the following formula: σ = L / AR, where σ represents the ionic conductivity, L represents the distance between the reference electrodes, A represents the area of ​​the membrane, and R represents the resistance of the sample.

[0130] Test Results

[0131] The main structural parameters and performance test results of Examples 1-4 and Comparative Examples 1-2 are shown in Table 1:

[0132] Table 1

[0133]

[0134] By incorporating a microporous framework layer, the tensile strength of each embodiment exceeded 50 MPa, and the elongation at break exceeded 150%. Compared to Comparative Example 1, which did not use a microporous framework layer, the mechanical properties of the embodiments were significantly improved. Although Comparative Example 2, which also used a microporous framework layer, showed improved tensile strength, the overall softness and elasticity of the anion exchange membrane were inferior to those of the embodiments due to the full filling of the anion exchange material.

[0135] Comparative Example 1, lacking the support and framework of a microporous framework layer, exhibited relatively high ionic conductivity but suffered severe swelling at 80°C, resulting in excessive dimensional changes and rapid degradation of the anion exchange membrane's lifespan. In Comparative Example 2, the swelling degree was lower in the portion supported and protected by the microporous framework layer; however, the thicker anion exchange layers on both sides still experienced significant swelling and loss at high temperatures. Overall, the degree of swelling and deformation was lower than in Comparative Example 1, but the ionic conductivity was relatively lower. The embodiments of this invention demonstrate good anti-swelling performance at high temperatures, with a dimensional change rate of less than 1.5% at 80°C, and an ionic conductivity exceeding 1.75 mS / cm, exhibiting good overall stability and durability.

[0136] Application Example 1

[0137] Application Example 1, based on the enhanced anion exchange membrane prepared in the aforementioned embodiments, further obtained an integrated membrane electrode, including the following steps:

[0138] S1: The enhanced anion exchange membrane of Example 1 is used;

[0139] S2: Prepare the anode catalyst slurry and cathode catalyst slurry:

[0140] (1) Dissolve 5g of ionomer in 40g of ethanol and 10g of water, then add 1g of 50% Pt / C catalyst while stirring magnetically. After dispersion, sonicate for 10min to obtain cathode catalyst slurry.

[0141] (2) Mix 30g of LDH catalyst with 6g of 10wt% anionic ionomer and 6g of 5wt% polytetrafluoroethylene mixed solution, 8g of isopropanol and 50g of dimethyl sulfoxide solvent, and then obtain the anode catalyst slurry after ultrasonic treatment for 10min and vacuum degassing for 5min.

[0142] S3: The enhanced anion exchange membrane obtained in Example 1 is adsorbed onto the heating platform of an ultrasonic spraying instrument, with the side uncoated by the anion conductor material facing upwards. A layer of cathode catalyst slurry is coated according to the parameters of a feed rate of 1.5 mL / min using an injection pump, an effective spraying area of ​​3 cm × 3 cm, and a heating platform temperature of 90 °C. The Pt / C catalyst loading is controlled at 0.8 mg / cm³. 2 .

[0143] S4: The anode catalyst slurry is applied to the anion exchange layer by thermal transfer to form the anode catalyst layer, including:

[0144] (1) Adsorb the PTFE release film onto the surface of the slot coating machine, and coat a layer of anodic catalyst slurry onto the surface of the release film at a coating speed of 0.5 m / min. After drying, the anodic catalyst transfer sheet is obtained. The loading of LDH catalyst is controlled at 8 mg / cm³. 2 .

[0145] (2) The anode catalyst transfer sheet is covered on the anion exchange layer on the surface of the enhanced anion exchange membrane, that is, the side without cathode catalyst, and the other side covered with cathode catalyst is covered with a blank release film.

[0146] (3) Using a hot press, the anode LDH catalyst is thermally transferred to the surface of the enhanced anion membrane for 2 hours at 90°C and 5MPa pressure to form an anode catalyst layer, and finally an integrated membrane electrode with a cathode catalyst layer and an anode catalyst layer on both sides is obtained.

[0147] Application Example 2

[0148] The difference between Application Example 2 and Application Example 1 is that, in step S3, the loading of the Pt / C catalyst is controlled at 0.3 mg / cm³. 2 .

[0149] Application Example 3

[0150] The difference between Application Example 3 and Application Example 1 is that, in step S4, the loading of the LDH catalyst is controlled at 15 mg / cm³.2 .

[0151] Application Example 4

[0152] The difference between Application Example 4 and Application Example 1 is that the enhanced anion exchange membrane of Example 4 is used, while the other preparation steps are the same.

[0153] Application Comparison 1

[0154] The difference between Application Comparison 1 and Application Example 1 is that both the cathode catalyst layer and the anode catalyst layer are formed by heat transfer and hot pressing simultaneously, including the following steps:

[0155] S1: The enhanced anion exchange membrane of Example 1 is used;

[0156] S2: Prepare the anode catalyst slurry and cathode catalyst slurry as above;

[0157] S3: The PTFE release film is adsorbed onto the heating platform of an ultrasonic spraying instrument. A layer of cathode catalyst slurry is coated using parameters including a feed rate of 1.5 mL / min, an effective spraying area of ​​3 cm × 3 cm, and a heating platform temperature of 90℃. After drying, the cathode catalyst transfer sheet is obtained. The Pt / C catalyst loading is controlled at 0.8 mg / cm³. 2 .

[0158] The PTFE release film is adsorbed onto the surface of a slot coating machine. At a coating speed of 0.5 m / min, a layer of anolyte catalyst slurry is coated onto the release film surface. After drying, the anolyte catalyst transfer sheet is obtained. The LDH catalyst loading is controlled at 8 mg / cm³. 2 .

[0159] S4: Cover the side of the enhanced anion exchange membrane of Example 1 that is not coated with anion conductor material with a cathode catalyst transfer sheet, and cover the other side of the anion exchange layer with an anode catalyst transfer sheet. Then, process it in a hot press at 90°C and 5MPa pressure for 2 hours to finally obtain a membrane electrode with a cathode catalyst layer and an anode catalyst layer on both sides respectively.

[0160] Application Comparison 2

[0161] The difference between Application Comparison 2 and Application Comparison 1 is that the anion exchange membrane with double-sided anion exchange layer of Comparison Example 2 is used to obtain a membrane electrode with cathode catalyst layer and anode catalyst layer on both sides respectively.

[0162] Application Comparison 3:

[0163] The difference between application comparison 3 and application comparison 1 lies in the different preparation methods and steps. The specific preparation methods are as follows:

[0164] S1: The enhanced anion exchange membrane of Example 1 is used;

[0165] S2: Prepare the anode catalyst slurry and cathode catalyst slurry:

[0166] (1) Dissolve 5g of ionomer in 40g of ethanol and 10g of water, then add 1g of 50% Pt / C catalyst while stirring magnetically. After dispersion, sonicate for 10min to obtain cathode catalyst slurry.

[0167] (2) Mix 30g of LDH catalyst with 6g of 10wt% ionomer solution, 6g of 5wt% polytetrafluoroethylene solution, 8g of isopropanol and 50g of dimethyl sulfoxide solvent, and then obtain the anode catalyst slurry after ultrasonic treatment for 10min and vacuum degassing for 5min.

[0168] S3: Fix conductive carbon cloth onto the heating platform of an ultrasonic spraying instrument, and coat a layer of catalyst slurry according to the parameters of a feed rate of 1.5 mL / min using an injection pump; an effective spraying area of ​​3 cm × 3 cm; and a heating platform temperature of 90 °C. After drying, a CCS-type cathode catalyst membrane electrode is obtained, with the Pt / C catalyst loading controlled at 0.8 mg / cm³. 2 .

[0169] S4: A 50 μm thick anode catalyst slurry is coated onto the porous nickel mesh surface at a coating speed of 0.5 m / min. After drying, a CCS-type anode catalyst membrane electrode is obtained. The LDH catalyst loading is controlled at 8 mg / cm³. 2 .

[0170] S5: The cathode catalyst membrane electrode and anode catalyst membrane electrode obtained in steps S3 and S4 are covered on both sides of the single-sided coated enhanced anion exchange membrane obtained in Example 1. Then, the cathode / anode catalyst membrane electrode and the enhanced anion exchange membrane are bonded together on a hot press at 90°C and 5MPa pressure.

[0171] Application Comparison 4

[0172] The difference between Application Comparison 4 and Application Comparison 3 is that the single-sided coated enhanced anion exchange membrane obtained in Example 4 is used in step S5.

[0173] Application Comparison 5

[0174] The difference between Application Comparison 5 and Application Comparison 3 is that the double-sided coated enhanced anion exchange membrane obtained in Comparative Example 2 is used in step S5.

[0175] Test Standards

[0176] 1. Membrane electrode interface resistivity: ASTM F84, GB / T1551, and GB / T1552 are used as reference test standards;

[0177] Current density at constant voltage of 2.2V: Refer to GB / T 20042.5-2009: Chinese National Standard "Proton Exchange Membrane Fuel Cells - Part 5: Membrane Electrode Test Methods".

[0178] Test Results

[0179] The main parameters and performance test results of Application Examples 1-4 and Application Comparison 1-5 are shown in Table 2:

[0180] Table 2

[0181]

[0182] In each application example, the membrane electrode interface resistivity is below 0.2 Ω·cm, and the current density at a constant voltage of 2V is 1.2 A / cm. 2 The present invention employs a liquid slurry coating method to apply the cathode catalyst slurry, allowing it to gradually impregnate into the pores on the opposite side of the microporous framework layer and the anion exchange layer. This not only stably supports the loading of the cathode catalyst slurry but also improves its loading stability. After the anode catalyst slurry is applied to the other side via a transfer method, the cathode catalyst layer and the anode catalyst layer are simultaneously hot-pressed together. The process is simple and the forming effect is good. Compared with applications 1 and 2, which only use heat transfer and hot-pressing methods, the present invention not only fully utilizes the structural advantages of the microporous framework layer but also selects a material application method that is more suitable for its structure, thereby obtaining an integrated membrane electrode product with better overall performance.

[0183] In comparison, Application Comparison 5 uses the double-sided coated anion exchange membrane of Comparative Example 2 and combines it with CCS process to prepare membrane electrodes. Its interface resistivity is 0.25 Ω·cm and the current density under a constant voltage of 2V is only 0.95 A / cm², which is significantly worse than Application Examples 1-4 and Application Comparison 1-4.

[0184] The above comparison verifies the innovation of the single-sided gradient coating and asymmetric loading process of the present invention: by controlling the pore size of the microporous framework layer and the differentiated processing strategy of the anode and cathode, the mechanical strength (tensile strength ≥ 55.8 MPa) is guaranteed while the interface resistivity and current density are simultaneously optimized, providing a reliable technical path for the engineering preparation of high-durability anion exchange membrane electrodes.

[0185] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A reinforced anion exchange membrane based on a microporous skeleton, characterized by, The microporous skeleton layer and the anion exchange layer laminated on one side of the microporous skeleton layer; The anion exchange layer comprises an anion conductor material; The anion conductor material fills part of the pores of the microporous skeleton layer to form an anion exchange region on the side close to the anion exchange layer; In the anion exchange region, the anion conductor material forms a gradually decreasing concentration gradient from the side close to the anion exchange layer inward.

2. The reinforced anion exchange membrane of claim 1, wherein, The microporous skeleton layer comprises at least one of a polyethylene film, a polypropylene film, a polyamide film, and a polytetrafluoroethylene film; The thickness of the microporous skeleton layer is 5-60 μm, the porosity is 40-80%, and the pore size is 0.05-2 μm.

3. The reinforced anion exchange membrane of claim 2, wherein, The microporous skeleton layer is subjected to hydrophilic modification treatment, comprising the following steps: A hydrophilic modification solution is prepared, the hydrophilic modification solution comprising one or more of an ethylene-vinyl alcohol copolymer and dopamine; The microporous skeleton is immersed in the hydrophilic modification solution and subjected to ultrasonic modification treatment.

4. The reinforced anion exchange membrane according to any one of claims 1 to 3, wherein The anion conductor material comprises an arylpiperidine resin.

5. The reinforced anion exchange membrane of claim 4, wherein, In terms of the total thickness L0 of the microporous skeleton layer: The thickness L1 of the anion exchange layer satisfies: 2%×L0≤L1≤20%×L0; From the side close to the anion exchange layer, the thickness L2 of the microporous skeleton layer filled with the anion conductor material satisfies: 20%×L0≤L2<100%×L0.

6. A method for producing the reinforced anion exchange membrane according to any one of claims 1 to 5, characterized by, Comprising the following steps: Step 1: hydrophilic modification treatment of the microporous skeleton layer; Step 2: preparation of casting solution C1 and casting solution C2 containing an anion conductor material, the concentration of casting solution C1 being lower than that of casting solution C2; Step 3: application of casting solution C1 to one side of the microporous skeleton layer, and repeated application after drying, the anion conductor material filling part of the pores of the microporous skeleton layer; Step 4: application of casting solution C2 to the side, vacuum drying, to obtain the anion exchange layer laminated on one side of the microporous skeleton layer, and the anion exchange region close to the anion exchange layer.

7. The production method according to claim 6, wherein In Step two, the casting solution C1 is configured to include the casting solutions C 1-1 , C 1-2 , …, and C 1-n , n is a natural number greater than 1; In step three, casting solution C 1-1 , casting solution C 1-2 ,... and casting solution C 1-n are sequentially applied and dried, so that the anion conductor material fills part of the pores of the microporous skeleton layer and forms a decreasing concentration gradient from the outside to the inside.

8. An integrated membrane electrode based on the enhanced anion exchange membrane according to any one of claims 1 to 5, characterized in that In sequence, an anode catalyst layer, a reinforced anion exchange membrane, and a cathode catalyst layer; The anode catalyst layer is connected to the anion exchange layer; The cathode catalyst layer is connected to the other side of the microporous skeleton layer away from the anion exchange layer; The pores on the side of the microporous skeleton layer close to the cathode catalyst layer are at least partially filled with a cathode catalyst to form a cathode catalyst region.

9. The integrated membrane electrode of claim 8, wherein, At least one of the following characteristics is satisfied: 1) The anode catalyst layer includes a layered double hydroxide (LDH) catalyst, with a loading of 2-20 mg / cm 2 ; 2) The cathode catalyst layer includes Pt / C catalyst, the loading amount is 0.2-1.0 mg / cm 2 .

10. A method for producing the integrated membrane electrode as claimed in claim 8 or 9, characterized by Comprising the following steps: S1: preparation of the reinforced anion exchange membrane; S2: preparation of anode catalyst slurry and cathode catalyst slurry; S3: application of the cathode catalyst slurry to the other side of the microporous skeleton layer away from the anion exchange layer, and filling part of the cathode catalyst into the pores on the side of the microporous skeleton layer close to the cathode catalyst layer to form the cathode catalyst layer and the cathode catalyst region; S4: formation of the anode catalyst layer on the anion exchange layer by the anode catalyst slurry.

Images