Ion channel-containing cross-linked polyaryl piperidinium polymer and preparation method and application of anion exchange membrane of ion channel-containing cross-linked polyaryl piperidinium polymer

Abstract

The invention discloses a preparation method and application of a cross-linked polyaryl piperidinium polymer containing ion channels and an anion exchange membrane thereof, a set amount of polyaryl piperidinium polymer is taken and dissolved in an aprotic polar solvent, a set weight percentage of 1, 3, 5-benzoyl trichloride is added, the mixture is placed in a set second temperature interval, the temperature is kept for 30-60 min, and the cross-linked polyaryl piperidinium polymer containing ion channels and the anion exchange membrane thereof are obtained. Pouring an ethyl acetate and isopropanol solution, and washing with water and ethanol for multiple times; drying to obtain a product; dissolving the product in alkyl halide; adding potassium carbonate and methyl iodide, and stirring for reaction; pouring into an ethyl acetate and isopropanol solution to precipitate, and washing with water, ethanol and isopropanol for multiple times; and drying in a vacuum environment to obtain the cross-linked polyaryl piperidinium polymer. The cross-linking agent is added for cross-linking reaction and quaternization, so that the prepared anion exchange membrane of the cross-linked polyaryl piperidinium polymer has higher mechanical strength and tensile strain, the conductivity is not influenced, and the electrochemical performance of the anion exchange membrane is not damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of anion exchange membranes, and particularly to a crosslinked polyarylpyridinium polymer containing ion channels, and a preparation method and application of an anion exchange membrane thereof. Background Art

[0002] In today's era of green energy, fuel cells and water electrolyzers are technologies for generating environmentally friendly energy or utilizing alternative fuels such as hydrogen, hydrocarbons, alcohols, greenhouse gases, ammonia, seawater, alkaline aqueous solutions, and acidic aqueous solutions to produce hydrogen. The structures of these two devices are similar, both including an anode layer, a cathode layer, a gas diffusion layer, and a membrane. Among the anode layer, cathode layer, and gas diffusion layer, the membrane plays a crucial role in the performance and stability of fuel cells and water electrolyzers. According to the type of membrane, these two devices are mainly divided into proton exchange membrane fuel cells and proton exchange membrane water electrolyzers, anion exchange membrane fuel cells and anion exchange membrane water electrolyzers, and solid oxide fuel cells and solid oxide water electrolyzers. Each type of fuel cell or water electrolyzer has its significant advantages and disadvantages.

[0003] Proton exchange membrane fuel cells or water electrolyzers require expensive noble metal electrodes and catalysts, need to use expensive metal bipolar plates, and have problems such as corrosion, thermal stability of the catalyst, and thermal stability of the membrane, which hinder their large-scale promotion in industry. Solid oxide fuel cells and water electrolyzers mainly face problems of high temperature, stability, and component cost. The performance of anion exchange membrane fuel cells and water electrolyzers is lower than that of proton exchange membrane fuel cells and water electrolyzers because the alkaline stability of the membrane is poor, and the conductivity and mechanical properties are limited, so they have not been promoted on a large scale either.

[0004] However, in terms of cost and performance, AEM (Anion Exchange Membrane) - based fuel cells and water electrolyzers are far superior to other fuel cells or water electrolyzers, and moreover, AEM - based (anion exchange membrane water electrolysis) fuel cells or water electrolyzers can be adjusted in terms of cost, stability, and performance. Therefore, AEM - based fuel cells and water electrolyzers are the key to promoting progress in the field of green energy.

[0005] Prior art has conducted research to solve the mechanical and stability problems of AEMs, such as in the literature [1]: Chen, N., & Lee, Y.M. (2021). Anion exchange polyelectrolytes for membranes and ionomers. Progress in Polymer Science, 113; literature [2]: Mandal, M. (2020). Recent Advancement on Anion Exchange Membranes for Fuel Cell and Water Electrolysis. ChemElectroChem, 8(1), 36 - 45; literature [3]: You, W., Noonan, K.J.T., & Coates, G.W. (2020). Alkaline-stable anion exchange membranes: A review of synthetic approaches. Progress in Polymer Science, 100. In particular, to solve the alkaline stability problem of anion exchange membranes, researchers have introduced nitrogen-containing cyclic structures, which can exhibit higher stability in alkaline media compared to ether-based membranes. In addition, introducing coupling molecules with fluorine atoms also improves its ionic conductivity to some extent. The main advantage of the nitrogen-containing cyclic structure is that quaternization can be easily achieved through alkyl halides and it is easy to be modified with other organic compounds containing complex halogenated groups.

[0006] In contrast, the AEMs containing sulfonium groups and phosphorus groups have limited ionic conductivity, chemical stability and thermal stability, which will limit their applications in fuel cells and water electrolyzers. And the AEMs with nitrogen-containing cyclic structures also have limitations in mechanical properties and chemical stability. So far, only a small amount of research work has been devoted to improving their mechanical properties and stability by crosslinking without compromising the actual performance of AEMs. The main advantage of the crosslinking method is that it can form hydroxide ion channels. Although there are already hydroxide ion channels in the main chain, the ionic conductivity of the membrane is still poor and the mechanical properties also decline.

[0007] Therefore, the present application provides a crosslinked polyarylpiperidinium polymer containing ion channels and a preparation method and application of its anion exchange membrane to improve the mechanical properties, ionic conductivity and stability of AEMs. Summary of the Invention

[0008] Based on the technical problems existing in the background art, the present invention proposes a crosslinked polyarylpiperidinium polymer containing ion channels and a preparation method and application of its anion exchange membrane.

[0009] The crosslinked polyarylpiperidinium polymer containing ion channels proposed by the present invention is composed of multiple crosslinked polyarylpiperidinium chains, and the molecular formula of the crosslinked polyarylpiperidinium chain is:

[0010]

[0011] Among them, R1 is a hydrogen ion or a methyl group; R2 is a methyl group or an alkyl chain with 1 - 10 carbon atoms; X - is I - , CO3 2- , Br - , Cl - , OH - or CF3SO3 - ;

[0012] A is an aromatic monomer;

[0013] B is a crosslinking agent, and the crosslinking agent includes a trifluorocarbonyl derivative and an aprotic solvent with at least one halogen atom;

[0014] The molecular formula of the trifluorocarbonyl derivative is:

[0015]

[0016] Among them, R ， is a benzene ring, a substituted benzene ring, a methyl group or (CH2)-Y, where Y is a halogen atom; the number of (CH2) is 1 to 10.

[0017] Furthermore, the A includes at least one fused aromatic ring or spirocyclic compound, and can be the same or different types of aromatic monomers; the B can be the same or different crosslinking agents.

[0018] The present invention provides a preparation method of a polyarylpiperidinium polymer containing ion channels, which includes the following steps:

[0019] S1. Mix the first crosslinking agent, the second crosslinking agent and the aromatic monomer A in a set molar ratio, and stir, and maintain the temperature at 0°C - 25°C to obtain a first mixed solution; among them, the first crosslinking agent includes but is not limited to 1 - methyl - 4 - piperidone, isatin, indole - 2,3 - dione and 3 - quinuclidinone;

[0020] S2. Slowly add trifluoroacetic acid and trifluoromethanesulfonic acid to the first mixed solution, and react at a preset temperature condition for a preset time to obtain a reaction product;

[0021] S3. Pour the reaction product into a second mixed solution;

[0022] S4. Filter and wash in a 0.5 - 1 M potassium carbonate solution at 20°C - 50°C.

[0023] S5. Wash repeatedly with water and dry in a vacuum oven at 45°C - 70°C for 24 hours to obtain the polyarylpiperidinium polymer.

[0024] Furthermore, the molar ratio of the first cross - linker to the second cross - linker is 0.01 - 99; the molar ratio of trifluoroacetic acid to trifluoromethanesulfonic acid is 0.5 - 13, the temperature condition is - 5°C to 3°C, and the time is 5 - 48 h; the second mixed solution consists of water and ethanol, and water:ethanol is 2:1 or 1:1.

[0025] The present invention provides a method for preparing a cross - linked polyarylpiperidinium polymer containing ion channels, which includes the following steps:

[0026] S1. Take a set amount of polyarylpiperidinium polymer and dissolve it in an aprotic polar solvent at a temperature range of 0°C - 60°C for a reaction time of 5 - 48 hours.

[0027] S2. Add a set weight percentage of 1,3,5 - benzenetricarbonyl trichloride at - 5°C - 10°C and stir at 25°C - 60°C for 12 - 36 hours.

[0028] S3. Pour into a set ratio of ethyl acetate and isopropanol solution and wash repeatedly with water and ethanol.

[0029] S4. Dry at 45°C - 65°C in a vacuum environment to obtain the product.

[0030] Quaternization: S5. Dissolve the product in an alkyl halide.

[0031] S6. Add potassium carbonate and iodomethane and stir - react in a 20°C - 40°C environment for 8 - 48 hours.

[0032] S7. Precipitate in an ethyl acetate and isopropanol solution and wash repeatedly with water, ethanol, and isopropanol.

[0033] S8. Dry at 45°C - 65°C in a vacuum environment to obtain the cross - linked polyarylpiperidinium polymer.

[0034] Furthermore, the weight percentage of 1,3,5 - benzenetricarbonyl trichloride is 0.5% - 40%; the ratio of the ethyl acetate and isopropanol solution is 1:1 or 2:1.

[0035] The present invention provides a method for preparing an anion - exchange membrane of a cross - linked polyarylpiperidinium polymer containing ion channels. For the cross - linked polyarylpiperidinium polymer containing ion channels, it further includes the following steps:

[0036] S1. Dissolve the cross-linked polyarylpyridinium polymer in an aqueous solution of dimethyl sulfoxide, N-methylpyrrolidone or isopropanol with a set concentration to obtain a polymer solution.

[0037] S2. Filter the polymer solution, coat it on a glass plate, and dry it at 50°C - 90°C for 8 - 24 hours.

[0038] S3. Heat it at 90°C - 100°C in a vacuum environment for 12 hours to obtain a preliminary membrane.

[0039] S4. Immerse it in 1M NaOH, 1M NaCl, 1M Na2CO3 solutions to obtain a cross-linked polyarylpyridinium polymer anion exchange membrane.

[0040] The present invention provides an anion exchange membrane, which is prepared by a preparation method of an anion exchange membrane of a cross-linked polyarylpyridinium polymer containing ion channels.

[0041] The present invention provides a membrane electrode assembly for an alkaline fuel cell, which includes an anion exchange membrane of a cross-linked polyarylpyridinium polymer containing ion channels.

[0042] The present invention provides a membrane electrode assembly for a water electrolyzer, which includes an anion exchange membrane of a cross-linked polyarylpyridinium polymer containing ion channels.

[0043] The present invention provides an alkaline fuel cell, which includes an anion exchange membrane of a cross-linked polyarylpyridinium polymer containing ion channels.

[0044] The present invention provides a water electrolyzer device, which includes an anion exchange membrane of a cross-linked polyarylpyridinium polymer containing ion channels.

[0045] The present invention has the following beneficial effects:

[0046] In this application, a polyarylpyridinium polymer is prepared by adding a cross-linking agent, and the polyarylpyridinium polymer is subjected to a cross-linking reaction and quaternization to obtain a cross-linked polyarylpyridinium polymer. An anion exchange membrane of the cross-linked polyarylpyridinium polymer is prepared with the cross-linked polyarylpyridinium polymer. The prepared anion exchange membrane has high mechanical strength and tensile strain, and does not affect the conductivity and damage the electrochemical performance of the anion exchange membrane, and has the advantages of low cost and high efficiency. Description of the Drawings

[0047] Figure 1 It is a process flow chart of the preparation method of the polyarylpyridinium polymer containing ion channels proposed by the present invention;

[0048] Figure 2Process flow chart of the preparation method of the crosslinked polyarylpiperidinium polymer containing ion channels proposed by the present invention;

[0049] Figure 3 Process flow chart of the preparation method of the anion exchange membrane of the crosslinked polyarylpiperidinium polymer containing ion channels proposed by the present invention;

[0050] Figure 4 1H-NMR spectrum of QCPDPP-78;

[0051] Figure 5 SEM image of QCPDPP-78;

[0052] Figure 6 SEM image of QCPTPP-82;

[0053] Figure 7 Mechanical property diagrams of different anion exchange membranes;

[0054] Figure 8 Linear sweep voltammograms of different crosslinked QCPDPP-78 membranes in 1 M KOH solution at 60 °C;

[0055] Figure 9 Curves of current (I) vs. time (t) of different crosslinked QCPDPP-78 membranes in 1 M KOH solution at 60 °C;

[0056] Figure 10 Curves of potential (E) vs. time (t) of different crosslinked QCPDPP-78 membranes in 1 M KOH solution at 60 °C;

[0057] Figure 11 Schematic diagrams of stability tests of potential, current and time for different crosslinked QCPDPP-78 membranes in 1 M KOH solution at 60 °C;

[0058] Figure 12 Schematic diagrams of stability tests of current, potential and time for different crosslinked QCPDPP-78 membranes in 1 M KOH solution at 60 °C;

[0059] Figure 13 Mechanical property diagrams of different anion exchange membranes;

[0060] Figure 14 Linear sweep voltammograms of different crosslinked membranes in 1 M KOH solution at 60 °C;

[0061] Figure 15 Schematic diagrams of stability tests of potential, current and time for different crosslinked QCPTPP-82 and QC@PDPP-78:PTPP82 membranes in 1 M KOH solution at 60 °C;

[0062] Figure 16 Figure showing the results of stability tests of different crosslinked QCPTPP-82 and QC@PDPP-78:PTPP82 membranes at a constant current, potential, and time in 1 M KOH solution at 60 °C. Detailed implementation manners

[0063] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used herein in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0065] The present application provides a crosslinked polyarylpiperidinium polymer containing ion channels, which is composed of multiple crosslinked polyarylpiperidinium chains. The molecular formula of the crosslinked polyarylpiperidinium chain is:

[0066]

[0067] Among them, R1 is a hydrogen ion or a methyl group; R2 is a methyl group or an alkyl chain having 1 to 10 carbon atoms; X - is I - 、CO3 2- 、Br - 、Cl - 、OH - or CF3SO3 - ; A is an aromatic monomer; B is a crosslinking agent, and the crosslinking agent includes a trifluorocarbonyl derivative and an aprotic solvent having at least one halogen atom; the molecular formula of the trifluorocarbonyl derivative is:

[0068]

[0069] Among them, R ， is a benzene ring, a substituted benzene ring, a methyl group or (CH2)-Y, where Y is a halogen atom; the number of (CH2) is 1 to 10.

[0070] In this embodiment, A can be two monomers of the same type and two monomers of different types, and B can be two crosslinking agents of the same type or two crosslinking agents of different types. The monomer A and the crosslinking agent B are crosslinked to obtain a polyarylpiperidinium polymer. In the molecular formula, R1 is -H or -CH3; R2 is -CH3 or an alkyl chain having 1 to 10 carbon atoms; X is I - 、CO3 2- 、Br - 、Cl - 、OH - or CF3SO3 - ; A represents the following aromatic monomers:

[0071]

[0072] B is a crosslinking agent, mainly including trifluorocarbonyl derivatives:

[0073]

[0074] wherein, R ， is a benzene ring, a substituted benzene ring, a methyl group, -(CH2)-Y, wherein the number of (CH2) is 1 to 10, and Y is a halogen atom; and at least includes a non-protic solution of a halogen atom. Preferably, the non-protic solution is 1,1-dichloromethane or dichloromethane (DCM).

[0075] In one embodiment, A includes at least one fused aromatic ring or spiro compound, and can be aromatic monomers of the same or different types; B can be crosslinking agents of the same or different types.

[0076] In specific implementation, the monomer A includes 1 to 6 different types of fused aromatic rings or spiro compounds. In addition, multiple monomers A in the molecular formula can be aromatic monomers of the same type or aromatic monomers of different types; and the crosslinking agent B can be a crosslinking agent of the same type or a crosslinking agent of different types to synthesize a new crosslinked PAP chain.

[0077] Referring to the attached Figure 1 , the present application provides a method for preparing a polyarylpiperidinium polymer containing an ion channel, including the following steps:

[0078] S1, mixing a first crosslinking agent, a second crosslinking agent and an aromatic monomer A in a set molar amount, and stirring, maintaining the temperature at 0°C - 25°C to obtain a first mixed solution; wherein, the first crosslinking agent includes but is not limited to 1-methyl-4-piperidone, isatin, indole-2,3-dione and 3-quinone;

[0079] S2, slowly adding trifluoroacetic acid and trifluoromethanesulfonic acid to the first mixed solution, and reacting at a preset temperature condition for a preset time to obtain a reactant;

[0080] S3. Pour the reactants into the second mixed solution;

[0081] S4. Filter and wash it in a 0.5 - 1 M potassium carbonate solution at 20°C - 50°C;

[0082] S5. Wash it with water multiple times and dry it in a vacuum oven at 45°C - 70°C for 24 hours to obtain the polyarylpiperidinium polymer.

[0083] In the above steps, the first cross - linker is one of 1 - methyl - 4 - piperidone, isatin, indole - 2,3 - dione, and 3 - quinuclidinone. Among them, the structures of isatin and 3 - quinuclidinone are:

[0084]

[0085] The second cross - linker is the above - mentioned cross - linker B, including an aprotic solution of a trifluorocarbonyl derivative and a halogen atom. The molar ratio of the first cross - linker to the second cross - linker is 0.01 - 99, and it is mixed with 0.1 or 1 mole of aromatic monomer A, and after stirring, the first mixed solution is obtained. Then, a superacid composed of trifluoroacetic acid and trifluoromethanesulfonic acid is slowly added to the first mixed solution and used as a catalyst in the polymerization reaction. Preferably, the molar ratio of trifluoroacetic acid to trifluoromethanesulfonic acid is 0.5 - 13. And it is placed in an environment of - 5°C to 3°C for reaction for 5 - 48 hours to obtain the reactants. Finally, the reactants are poured into the second mixed solution to obtain the fibrous polyarylpiperidinium polymer. Preferably, the second mixed solution is prepared from water and ethanol, and the ratio of water to ethanol is 2:1 or 1:1.

[0086] Specifically, for synthesizing the polyarylpiperidinium polymer (PDPP - x, where x represents the molar ratio of the first cross - linker), first add diphenyl (DP) and N - methyl - 4 - piperidone to an aprotic solvent and stir. Maintain the temperature between 0 - 25°C. After 15 - 20 minutes, slowly add a mixture of trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFSA) with a molar ratio of 0.5 - 12.0 while stirring, and let the reaction proceed for 8 - 48 hours. The specific time can be determined by the viscosity of the solution. Then pour the reaction mixture into an ethanol - water solution to form a fibrous solid polymer. Then filter it and wash it overnight in a 0.5 - 1 molar potassium carbonate solution at a high temperature of 20°C - 50°C. Finally, wash it with water multiple times and dry it in a vacuum oven at 45°C - 70°C for 24 hours to obtain the polyarylpiperidinium polymer.

[0087] Reference appendix Figure 2 , this application proposes a preparation method of a cross - linked polyarylpiperidinium polymer containing ion channels, including the following steps:

[0088] S1. Take a set amount of polyarylpiperidinium polymer and dissolve it in an aprotic polar solvent at a temperature range of 0 °C - 60 °C for a reaction time of 5 - 48 hours;

[0089] S2. Add a set weight percentage of 1,3,5-benzenetricarbonyl trichloride at -5 °C - 10 °C and stir for 12 - 36 hours at 25 °C - 60 °C;

[0090] S3. Pour in a set ratio of ethyl acetate and isopropanol solution and wash repeatedly with water and ethanol;

[0091] S4. Place it in a drying environment at 45 °C - 65 °C under vacuum to obtain the product;

[0092] Quaternization: S5. Dissolve the product in an alkyl halide;

[0093] S6. Add potassium carbonate and iodomethane and stir and react for 8 - 48 hours in an environment of 20 °C - 40 °C;

[0094] S7. Pour it into ethyl acetate and isopropanol solution to precipitate and wash repeatedly with water, ethanol and isopropanol;

[0095] S8. Place it in a drying environment at 45 °C - 65 °C under vacuum to obtain the cross-linked polyarylpiperidinium polymer.

[0096] In the above steps, first take the polyarylpiperidinium polymer and dissolve it in an aprotic polar solution. Among them, the aprotic polar solvent is dimethyl sulfoxide (DMSO) or N-methylpiperidone (NMP). Then add an aromatic carbonyl halide as a cross-linking agent for cross-linking. Preferably, 1,3,5-benzenetricarbonyl trichloride (BTCTC) is used, and other cross-linking agents such as dihaloalkanes with a carbon chain length of 1 - 10 can also be used. Further, at -5 °C - 10 °C, the weight percentage of the cross-linking agent added is 0.5% - 40%, stir for 12 - 36 hours at 20 °C - 60 °C, then pour in a set ratio of ethyl acetate and isopropanol solution and wash repeatedly with water and ethanol; then place it in a drying environment at 45 °C - 65 °C under vacuum to obtain the product.

[0097] Then carry out the quaternization reaction, that is, mix it with alkyl halides of different chain lengths. Preferably, iodomethane is used. Dissolve the product in an alkyl halide, then add potassium carbonate and iodomethane, stir and react for 8 - 48 hours in an environment of 20 °C - 40 °C, pour it into ethyl acetate and isopropanol solution to produce precipitation, and wash repeatedly with water, ethanol and isopropanol to obtain the cross-linked polyarylpiperidinium polymer.

[0098] Specifically, for cross-linked polyarylpiperidinium polymers (cross-linked PDPP-x polymers, where x represents the molar ratio of the cross-linking agent), an appropriate amount of PDPP-x is first dissolved in an aprotic polar solvent, and 1,3,5-benzenetricarbonyl trichloride with a weight percentage of 0.5 - 40% is added in a low-temperature environment of -5°C to 10°C. Then, it is placed in a temperature range of 25°C - 60°C and stirred for reaction for 12 - 36 hours. Subsequently, it is poured into a solution of ethyl acetate:isopropyl alcohol with a ratio of 2:1, washed multiple times with water and ethanol, and dried in a temperature range of 45°C - 65°C under a vacuum environment to obtain a preliminary product. Then, the product is subjected to a quaternization reaction, that is, the remaining piperidine nitrogen is quaternized by using different alkyl halides. Preferably, the alkyl halide is methyl iodide. First, the product is dissolved in a polar aprotic solvent, then potassium carbonate and methyl iodide are added, and the mixture is stirred for reaction for 8 - 48 hours. Then, it is poured into a solution of ethyl acetate and isopropyl alcohol to obtain a solid product. The solid product is washed multiple times with water, ethanol, and isopropyl alcohol, and finally dried in a temperature range of 45°C - 65°C under a vacuum environment to complete the quaternization reaction and obtain a cross-linked polyarylpiperidinium polymer (CPDPP-x, where x represents the molar ratio of the cross-linking agent).

[0099] Please refer to the attached Figure 3 , and this application proposes a method for preparing an anion exchange membrane of a cross-linked polyarylpiperidinium polymer containing ion channels, including the following steps:

[0100] S1, Dissolve the cross-linked polyarylpiperidinium polymer in dimethyl sulfoxide, N-methylpyrrolidone, or an aqueous solution of isopropyl alcohol with a set concentration to obtain a polymer solution;

[0101] S2, Filter the polymer solution, coat it on a glass plate, and dry it at 50°C - 90°C for 8 - 24 hours;

[0102] S3, Heat it at 90°C - 100°C in a vacuum environment for 12 hours to obtain a preliminary membrane;

[0103] S4, Immerse it in 1M NaOH, 1M NaCl, and 1M Na2CO3 solutions to obtain a cross-linked polyarylpiperidinium polymer anion exchange membrane.

[0104] In specific implementation, the crosslinked polyarylpiperidinium polymer is dissolved in dimethyl sulfoxide (DMSO) or N-methylpyrrolidone (NMP) or aqueous isopropanol solution with a concentration of 2-30% to obtain a polymer solution. Then the polymer solution is filtered and coated on a glass plate, and then dried at 50°C - 90°C for 8 - 24 hours, and then heated in a vacuum environment at 90°C - 100°C for 12 hours to wash away the residual organic solvents, obtaining a preliminary membrane. Finally, the preliminary membrane is soaked in a solution of 1 mol of NaOH, 1M NaCl and 1M Na2CO3 to exchange the halide ions for hydroxide ions, obtaining a crosslinked polyarylpiperidinium polymer anion exchange membrane.

[0105] Specifically, the crosslinked polyarylpiperidinium polymer is dissolved in dimethyl sulfoxide, or N-methylpyrrolidone, or aqueous isopropanol solution, and stirred to obtain a homogeneous polymer solution. The polymer solution is coated on a glass plate and dried at an ambient temperature of 50 - 90°C, and then heated at 90°C - 100°C and in a vacuum environment for 12 hours to obtain a preliminary membrane. The obtained preliminary membrane is soaked in 1M NaCl, 1M Na2CO3 and 1M NaOH to obtain a crosslinked polyarylpiperidinium polymer anion exchange membrane containing different anions. Finally, before use, the anion exchange membrane is washed with water multiple times.

[0106] The present application proposes an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels, which is prepared by a preparation method of an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels.

[0107] The present invention provides a membrane electrode assembly applied to an alkaline fuel cell, including an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels.

[0108] In this embodiment, the anion exchange membrane of the crosslinked polyarylpiperidinium polymer is used as the anion exchange membrane electrode assembly (MEA) of an alkaline fuel cell.

[0109] The present invention provides a membrane electrode assembly applied to a water electrolyzer, including an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels.

[0110] In the embodiment, the anion exchange membrane of the crosslinked polyarylpiperidinium polymer can also be used as the anion exchange membrane electrode assembly (MEA) of a water electrolyzer.

[0111] The present invention provides an alkaline fuel cell, including an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels.

[0112] In this embodiment, a cross-linked polyarylpiperidinium polymer is used as an adhesive in electrode preparation. A 2 to 10% w / w cross-linked polyarylpiperidinium polymer solution is mixed with a catalyst and cast on nickel foam or carbon cloth; where w / w represents concentration.

[0113] The present invention provides a water electrolysis cell device including an anion exchange membrane of a cross-linked polyarylpiperidinium polymer containing an ion channel.

[0114] In this embodiment, a cross-linked polyarylpiperidinium polymer is used as an adhesive in electrode preparation. A 2 to 10% w / w cross-linked polyarylpiperidinium polymer solution is mixed with a catalyst and cast on nickel foam or carbon cloth; where w / w represents concentration.

[0115] Furthermore, the present application can be used to prepare anion exchange electrolyte membranes for batteries and fuel cells.

[0116] Example 1: Based on cross-linked poly(diphenylpiperidinium) polymer (CPDPP-78), its reaction formula is:

[0117]

[0118] Among them, (a) the reaction process is as follows: Add 20 mL of dichloromethane or 1,2-dichloromethane to a 500 mL three-necked flask, then add 0.1 mole of diphenyl (DP), and then stir and react for 10 minutes until DP is completely dissolved. Cool the reaction to 0 °C, add the first cross-linking agent, that is, 0.018 mole of trifluoroacetylbenzene. Add the second cross-linking agent, that is, 0.082 mole of N-methyl-4-piperidone (m-PiP), under cooling conditions and keep the reaction temperature at 0 °C. After vigorously mixing the reagents, slowly add the mixed acid, which is 1 equivalent of trifluoroacetic acid (TFA) and 10 equivalents of trifluoroethanesulfonic acid (TFSA). Keep the reaction temperature at 0 °C during the addition process and react at the same temperature for 24 - 48 hours. Pour the viscous reaction solution into a solution of ethanol: water solution of 1:1 to obtain a solid PAP (polyarylpiperidinium) polymer. Filter and wash with water multiple times to obtain a pure PDPP (polydiphenylpiperidinium) polymer.

[0119] (b) The reaction process is the cross-linking (CPDPP-78) of PDPP-78 (polydiphenylpiperidinium polymer, 78 represents the molar number of diphenyl): Dissolve the above-synthesized PDPP in DMSO or NMP respectively, and add 1 wt% - 5 wt% of a trihalocarbonyl derivative (such as 1,3,5-benzenetricarbonyl chloride). The reaction is carried out in N-dimethyl sulfoxide (DMSO) or N-methylpyrrolidone (NMP) for 36 hours. Then pour it into a mixture of ethyl acetate and isopropanol to obtain the product, and store it at room temperature after washing.

[0120] (c)Quaternization of CPDPP-78 (crosslinked polydiphenylpiperidinium polymer): Dissolve the crosslinked PAP polymer in DMSO or NMP, and add 2 to 2.5 times of methyl iodide for quaternization. Stir the mixture at room temperature for 48 hours, then pour it into a solvent of ethyl acetate:isopropanol at a ratio of 1:3 to obtain a brown product. Then wash the product with ethanol and water multiple times, filter it, and place it in a vacuum dryer at 55 °C to obtain the quaternized crosslinked polydiphenylpiperidinium polymer (QCPDPP-78), where Q is the English abbreviation of the quaternization reaction.

[0121] Preparation of crosslinked polydiphenylpiperidinium anion exchange membrane:

[0122] Dissolve the crosslinked polydiphenylpiperidinium polymer in NMP or DMSO, and stir for at least 24 hours to obtain a homogeneous solution with a viscosity between 80 - 120 MPa·s. Then filter the solution and cast it on a 10 cm×10 cm glass plate to obtain a preliminary membrane. Further immerse the preliminary membrane in 1M NaOH, 1M NaCl, and 1M Na2CO3 to exchange OH - 、Cl - and CO3 2- ions, then wash it with water multiple times, and dry it at room temperature.

[0123] In Figure 4 , the 1H-NMR spectrum of CPDPAP-78 contains multiple aromatic bonds, mainly showing signals between 7.0 - 8.0 δ ppm, while the methyl group where the piperidone proton is directly connected to the nitrogen atom shows signals between 2.5 - 4.0 δ ppm. Generally speaking, the proton NMR spectrum confirms the successful synthesis of CPDPP-78.

[0124] As Figure 5 shown, the surface of the crosslinked PDPP-78 shows microphase separation, where the black part represents the hydrophobic chain, and the white part represents the hydrophilic chain. The water absorption capacities of QPDPP-78 and QCPDPP-78 at 60 °C are 130% and 80% respectively, while the ionic conductivities are 150 mS / cm and 180 mS / cm respectively. The IEC (ion exchange capacity) of QPDPP-78 and CQPDPP-78 are 2.1 ± 0.5 meq. / g and 2.5 ± 0.5 meq. / g respectively.

[0125] In Figure 7 , with the increase of the crosslinking agent, the mechanical strengths of QPDPP-78 and QCPDPP-78 from 1 wt% to 10% increase significantly, but the tensile strain decreases.

[0126] Figure 8Linear sweep voltammogram (LSV) of different cross-linked QCPDPP-78 membranes in 1 M KOH solution at 60 °C. Potential range: 1.0 - 2.0 V; Scan rate: 10 mV / min; Sample area: 1 cm 2 As can be seen from the figure, the current density of the quaternized cross-linked poly(diphenylpiperidinium) polymer ion exchange membrane with a concentration of 1 wt% is the largest.

[0127] Figure 9 Graph of current (I) vs. time (t) of different cross-linked QCPDPP-78 membranes in 1 M KOH solution at 60 °C. Applied potential is 2.0 V, sample area is 1 cm 2 As can be seen from the figure, the electrochemical performance of the quaternized cross-linked poly(diphenylpiperidinium) polymer ion exchange membrane with a concentration of 1 wt% is more stable over time at the same temperature.

[0128] Figure 10 Graph of potential (E) vs. time (t) of different cross-linked QCPDPP-78 membranes in 1 M KOH solution at 60 °C. Current density is 0.8 A / cm 2 ; Sample area is 1 cm 2 As can be seen from the figure, at the same current density and temperature, the curve of the quaternized cross-linked poly(diphenylpiperidinium) polymer ion exchange membrane with a concentration of 1 wt% is the most stable and has the highest durability.

[0129] Figure 11 Schematic diagram of the stability test of different cross-linked QCPDPP-78 membranes in 1 M KOH solution at 60 °C. The test method is constant potential and the applied voltage of current (I) vs. time (t) is 2.0 V, sample area is 1 cm 2 As can be seen from the figure, as time increases, the current of QCPDPP-78@1 wt% is the highest.

[0130] Figure 12 Schematic diagram of the stability test of different cross-linked QCPDPP-78 membranes in 1 M KOH solution at 60 °C with constant current, potential vs. time; Current density is 0.8 A / cm 2 , Sample area is 1 cm 2 As can be seen from the figure, the higher the concentration of the quaternized cross-linked poly(diphenylpiperidinium) polymer ion exchange membrane, the higher its potential.

[0131] Example 2: The molecular formula of the preparation process of cross-linked poly(triphenylpiperidinium) polymer (CPTPP) is:

[0132]

[0133] Among them, the preparation steps of reaction process (a) are the same as those in Example 1, but the monomer used is 0.1 mole of biphenyl (TP), and the first cross-linking agent and the second cross-linking agent used are also the same as those in Example 1, obtaining PTPP-82 (poly(biphenylpiperidinium) polymer, where 82 represents the molar number of triphenyl or the number of triphenyl units).

[0134] The preparation steps of reaction process (b) and reaction process (c) are the same as those in Example 1. Reaction process (b) is the cross-linking of PTPP-82 to obtain CPTPP-82. Reaction process (c) is the quaternization of CPTPP-82 to obtain QCPTPP-82.

[0135] Figure 6 is the scanning electron microscope image of QCPTPP-82. It can be seen from Figure 6 that the surface of QCPTPP-82 has microphase separation. The dark regions in the figure represent hydrophobic chains, and the white parts represent hydrophilic chains. The water absorption capacities of QPTPP-82 and QCPTPP-82 at 60 °C are 56% and 45% respectively, while the ionic conductivities are 135 mS / cm and 150 mS / cm respectively. The IEC (ion exchange capacity) of QPTPP-82 and QCPTPP-82 are 2.0 ± 0.5 meq. / g and 2.3 ± 0.3 meq. / g respectively.

[0136] Example 3: Cross-linking two different types of poly(arylpiperidinium) chains, and their molecular formula is:

[0137]

[0138] Mix the two PAP polymers, PDPP-78 and PTPP-82 in Example 1, according to a mass ratio of 0.05 - 0.95, and add 0.5% - 20% wt of cross-linking agent to the mixture. Reaction process (b) is cross-linking, and reaction process (c) is quaternization. The processes of cross-linking, quaternization and membrane preparation are the same as those in Example 1.

[0139] To compare PAP chains of different types, taking the mass ratio of PDPP-78 and PTPP-82 as 1:4 as an example, it is named QC@PDPP78:PTPP82; and a non-cross-linked membrane is prepared, that is, obtained by mixing QPTPP-82 and QPDPP-78, and named Q@PDPP78:PTPP82.

[0140] Please refer to Figure 13 , which is the mechanical property test result graph of different anion exchange membranes. It can be seen from the figure that the mechanical properties of the ion exchange membrane of poly(diphenylpiperidinium) polymer without cross-linking are much lower than those of the ion exchange membrane of poly(diphenylpiperidinium) polymer with cross-linking and quaternization.

[0141] At 60 °C, the water absorption capacities of Q@PDPP78:PTPP82 and QC@PDPP78:PTPP82 are 100% and 95% respectively, while the ionic conductivities are 130 mS / cm and 165 mS / cm respectively. The IECs of Q@PDPP78:PTPP82 and QC@PDPP78:PTPP82 are 1.85 ± 0.3 meq. / g and 2.25 ± 0.6 meq. / g respectively.

[0142] As Figure 13 shown, it is the test result diagram of the mechanical properties of different anion exchange membranes. In Figure 13 , the mechanical strength and tensile strain of QC@PDPP78:PTPP82 are far superior to those of Q@PDPP78:PTPP82, which is due to the interconnection of PDPP and PTPP chains in the cross-linked PAP membrane. In Figure 13 , the mechanical strength and tensile strain of QPTPP-82 and QCPTPP-82@ are significantly improved after cross-linking.

[0143] Figure 14 Figure shows the linear sweep voltammogram (LSV) of different cross-linked membranes in 1 M KOH solution at 60 °C, the potential range is 1.0 - 2.0 V, the scan rate is 10 mV / minute, and the sample area is 1 cm 2 . As Figure 14 can be seen, the stability test carried out at a constant current density of 0.8 A / cm2 shows that the voltage decay is negligible. The performance of QCPTPP-82 is slightly lower than that of QCPDPP-78 because the presence of larger aromatic rings hinders the water absorption capacity of QCPTPP-82. Figure 15 Figure shows the stability test of different cross-linked QCPTPP82 and QC@PDPP78:PTPP82 membranes in 1 M KOH solution at 60 °C, the test method is constant potential - current (I) vs. time (t); applied voltage: 2.0 V; sample area: 1 cm 2 .

[0144] As Figure 14 and Figure 15 shown, at a temperature of 60 °C and a potential of 2.0 V, the current density of QPTPP-82 increases from 0.77 to 0.96 A / cm2. Generally speaking, the performance of these two membranes is improved compared with their original membranes. Thus, it can be seen that the QC@PDPP78:PTPP82 membrane is far superior to the non-cross-linked mixed PAP.

[0145] The present invention improves the electrical properties of AEM membranes through crosslinking. Compared with QPDPP-78 and QPTPP-82, QCPDPP-78 or QCPTPP-82 has a higher current density and a lower voltage decay. Moreover, it can improve the mechanical properties, electrochemical properties, especially the voltage drop, and can provide ion capture channels for hydroxide ions. The improvement in the properties of the crosslinked membrane is mainly due to the formation of ion channels and hydroxide ion capture mechanisms, while the non-crosslinked membrane does not have such properties.

[0146] Figure 16 Figure showing the results of the constant current, potential and time stability tests of different crosslinked QCPTPP82 and QC@PDPP-78:PTPP82 membranes in 1M KOH solution at 60°C. As Figure 16 shown, the voltage decay value of QC@PDPP78:PTPP82 is lower than that of Q@PDPP78:PTPP82. Therefore, crosslinking two different PAPs solves the mechanical property problem and does not damage the electrochemical properties of the membrane, and has a longer lifespan.

[0147] In summary, compared with the prior art, in the present application, a polyarylpiperidinium polymer is prepared by adding a crosslinking agent, and the polyarylpiperidinium polymer is subjected to a crosslinking reaction and quaternization to obtain a crosslinked polyarylpiperidinium polymer. An anion exchange membrane of the crosslinked polyarylpiperidinium polymer is prepared from the crosslinked polyarylpiperidinium polymer. The prepared anion exchange membrane has high mechanical strength and tensile strain, and does not affect the conductivity and damage the electrochemical properties of the anion exchange membrane. At the same time, it has the advantages of low cost and high efficiency.

[0148] Characterization and testing:

[0149] (1) Specifically, obtained by scanning electron microscopy (SEM): The sample is cut into 0.2 cm × 0.2 cm and pasted on a carbon tape. To improve the electron conductivity, a layer of platinum is sputtered on the membrane surface, and then the sample holder is injected into the SEM microscope. Preferably, surface topography and cross-sectional images are taken.

[0150] (2) Specifically, ICE is the ion exchange capacity. Ion exchange capacity (IEC) test method: The IEC of each membrane is confirmed by the back-titration method. The precisely cut CPAP membrane is immersed in 0.01M HCl for 2 days. Then, the membrane is taken out and the remaining dispersion is titrated with 0.01M NaOH. The IEC is calculated using the following formula;

[0151]

[0152] where V and C correspond to volume and concentration respectively, and w d is the mass of the dry sample.

[0153] (3) When testing the conductivity of the ion exchange membrane: The ionic conductivity of the membrane is obtained through electrochemical impedance spectroscopy (EIS). The conductivity of the membrane is tested at four different temperatures between 30 °C and 80 °C. Each EIS test is carried out on a CORETEST electrochemical workstation (CS310M potentiostat / galvanostat / ZRA). The frequency of the EIS test is set from 100 kHz to 1 Hz, and the potential amplitude is set at 20 mV. The test sample is cut into a circle with a diameter of 10 cm and clamped in a self-made laboratory device with platinum wires as electrodes (four-probe electrode). Nitrogen with water vapor is used to control the humidity in the test cell. The resistance value obtained from the Nyquist plot is used to calculate the ionic conductivity of the membrane. The ionic conductivity of each membrane is defined using the following formula:

[0154]

[0155] 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.

[0156] (4) When testing the water absorption rate and swelling rate of the membrane: Each sample is cut into a size of 1 cm × 1 cm and soaked in water at a specific temperature for 24 hours or 48 hours. The changes in the mass and length of the sample are measured. Then the sample is dried and its length and weight are measured again. The following formulas are used to calculate the water absorption rate (WU) and swelling rate (SR) of the membrane.

[0157]

[0158] where W and L represent the weight and length of the sample respectively, and w and d represent the wet and dry sample tensile strength test methods respectively.

[0159] (5) The mechanical properties of the sample are tested on an HZ-1004B mechanical testing machine. The size of the wet membrane sample is 5 × 0.5 cm, and the tensile rate is set at 5 mm / min.

[0160] (6) Electrochemical performance testing of the membrane: To expand the application of the crosslinked PAP (CPAP) membrane, it is further used as an anion exchange membrane in an alkaline membrane electrolyzer to produce hydrogen. The cathode material is made by spraying Pt / C (platinum on carbon) containing 75% Pt (platinum) on carbon cloth, and finally contains 0.1 - 1.0 mg / cm² of Pt, while the anode material is made by casting a nickel-iron oxide double hydroxide (NiFe-LDH) on nickel foam, with a content of 3 mg / cm² to 10 mg / cm². Different types of electrochemical methods are used to confirm the performance of CPAP. Linear sweep voltammograms are recorded between 1.0 V and 2.0 V at a scan rate of 5 mV / s. The durability test is carried out at a current density of 0.8 A / cm² for several hours, and the test temperature is 60 °C.

[0161] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, with equivalent substitution or change, should be covered by the protection scope of the present invention.

Claims

1. A crosslinked polyarylpiperidinium polymer containing ion channels, characterized in that, Composed of multiple cross-linked polyarylpiperidinium chains, the molecular formula of the cross-linked polyarylpiperidinium chain is: Wherein, R1 is a hydrogen ion or a methyl group; R2 is a methyl group or an alkyl chain having 1 to 10 carbon atoms; X - is I - , CO3 2- , Br - , Cl - , OH - or CF3SO3 - ; A is an aromatic monomer; B is a cross-linking agent, and the cross-linking agent includes a trifluorocarbonyl derivative and an aprotic solvent with at least one halogen atom; The molecular formula of the trifluorocarbonyl derivative is: wherein, R ， is a benzene ring, a substituted benzene ring, a methyl group or (CH2)-Y, wherein Y is a halogen atom; the number of (CH2) is from 1 to 10.

2. The crosslinked polyarylpiperidinium polymer containing ion channels according to claim 1, wherein A includes at least one fused aromatic ring or spiro compound, and can be the same or different types of aromatic monomers; B can be the same or different cross-linking agents.

3. Preparation method of polyarylpiperidinium polymer containing ion channels, characterized in that, Including the following steps: S1. Mix the first cross-linking agent, the second cross-linking agent and the aromatic monomer A in a set molar ratio, and stir, maintaining the temperature at 0°C - 25°C to obtain a first mixed solution; wherein, the first cross-linking agent includes but is not limited to 1-methyl-4-piperidone, isatin, indole-2,3-dione and 3-quinone; S2. Slowly add trifluoroacetic acid and trifluoromethanesulfonic acid to the first mixed solution, and react at a preset temperature condition for a preset time to obtain a reactant; S3. Pour the reactant into a second mixed solution; S4. Filter, and wash in a 0.5 - 1M potassium carbonate solution at 20°C - 50°C; S5. Wash with water multiple times, and dry in a vacuum oven at 45°C - 70°C for 24 hours to obtain a polyarylpiperidinium polymer.

4. The preparation method of the polyarylpiperidinium polymer containing ion channels according to claim 3, characterized in that, The molar ratio of the first cross-linking agent to the second cross-linking agent is 0.01 - 99; The molar ratio of trifluoroacetic acid to trifluoromethanesulfonic acid is 0.5 - 13, the temperature condition is -5°C to 3°C, and the time is 5 - 48h; The second mixed solution is composed of water and ethanol, and water:ethanol is 2:1 or 1:

1.

5. Preparation method of crosslinked polyarylpiperidinium polymer containing ion channels, characterized in that, Including the following steps: S1. Take a set amount of polyarylpiperidinium polymer and dissolve it in an aprotic polar solvent, and the temperature range is 0°C - 60°C, and the reaction time is 5 - 48 hours; S2. Add a set weight percentage of 1,3,5-benzenetricarbonyl trichloride at -5°C - 10°C, and stir at 25°C - 60°C for 12 - 36 hours; S3. Pour into a set ratio of ethyl acetate and isopropanol solution, and wash with water and ethanol multiple times; S4. Dry at 45°C - 65°C and in a vacuum environment to obtain a product; Quaternization: S5. Dissolve the product in an alkyl halide; S6. Add potassium carbonate and iodomethane, and stir and react in a 20°C - 40°C environment for 8 - 48 hours; S7. Pour into ethyl acetate and isopropanol solution to precipitate, and wash with water, ethanol and isopropanol multiple times; S8. Dry at 45°C - 65°C and in a vacuum environment to obtain a cross-linked polyarylpiperidinium polymer.

6. The preparation method of the crosslinked polyarylpiperidinium polymer containing ion channels according to claim 5, characterized in that, The weight percentage of 1,3,5-benzenetricarbonyl trichloride is 0.5% - 40%; The ratio of the ethyl acetate and isopropanol solution is 1:1 or 2:

1.

7. Preparation method of an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels, characterized in that, Including the cross-linked polyarylpiperidinium polymer containing an ion channel according to any one of claims 1 - 2, and further including the following steps: S1. Dissolve the cross-linked polyarylpiperidinium polymer in a dimethyl sulfoxide, N-methylpyrrolidone or aqueous isopropanol solution with a set concentration to obtain a polymer solution; S2. Filter the polymer solution, and coat it on a glass plate, and dry at 50°C - 90°C for 8 - 24 hours; S3, heat it at 90°C - 100°C in a vacuum environment for 12 hours to obtain a preliminary membrane; S4, soak it in a solution of 1M NaOH, 1M NaCl, and 1M Na2CO3 to obtain a crosslinked polyarylpiperidinium polymer anion exchange membrane.

8. An anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels, characterized in that, It is prepared by the method for preparing an anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels according to claim 7.

9. A membrane electrode assembly applied to an alkaline fuel cell, characterized in that It includes the anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels according to claim 8.

10. A membrane electrode assembly applied to a water electrolysis cell, characterized in that, It includes the anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels according to claim 8.

11. An alkaline fuel cell, characterized in that, It includes the anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels according to claim 8.

12. A water electrolysis cell device, characterized in that, It includes the anion exchange membrane of a crosslinked polyarylpiperidinium polymer containing ion channels according to claim 8.

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