Anion exchange polymers and membranes for electrolysis

Abstract

The anion exchange polymer comprises a plurality of repeating units of formula (I). The polymer can be synthesized by a superacid catalyzed polyhydroxyalkylation reaction of monomers Ar1 ', Ar2', and X1 'to form a neutral precursor polymer followed by a Menshutkin reaction to convert the neutral precursor polymer to an anion exchange polymer. Anion exchange membranes and membrane electrode assemblies incorporating anion exchange polymers are also described. # imgabs0 #

Description

[0001] Priority declaration

[0002] This application claims priority to U.S. patent application No. 17 / 823,975, filed on September 1, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] Hydrogen plays an important role in the path towards an environmentally friendly, low-carbon energy structure as an energy carrier for grid balancing or power-to-gas and power-to-liquid processes. Water electrolysis produces high-quality hydrogen by electrochemically decomposing water into hydrogen and oxygen; the reaction is given by the following equation 1. The water electrolysis process is an endothermic process, and electricity is the energy source. When the method is operated by renewable energy such as wind, solar or geothermal energy, water electrolysis has a zero carbon footprint. The main water electrolysis technologies include alkaline electrolysis, proton exchange membrane (PEM) water electrolysis (such as Figure 1 PEMWE as shown), anion exchange membrane (AEM) water electrolysis (such as Figure 2 AEMWE) and solid oxide water electrolysis shown.

[0004] like Figure 1 As shown, in the PEMWE system 100, the anode 105 and the cathode 110 are separated by a solid PEM electrolyte 115, such as the one shown in the trademark A fluorinated copolymer based on sulfonated tetrafluoroethylene sold by the Chemours company. The anode and cathode catalysts typically comprise IrO2 and Pt, respectively. At the positively charged anode 105, pure water 120 is oxidized to produce oxygen 125, electrons (e - ) and protons; the reaction is given by Equation 2. Protons are transported from the anode 105 to the cathode 110 through the proton-conducting PEM 115. At the negatively charged cathode 110, a reduction reaction occurs in which electrons from the cathode 110 are given to protons to form hydrogen 130; the reaction is given by Equation 3. The PEM 115 not only conducts protons from the anode 105 to the cathode 110, but also separates the H2 gas 130 and O2 gas 125 produced in the water electrolysis reaction. PEM water electrolysis is one of the advantageous methods for converting renewable energy into high-purity hydrogen, with the advantages of compact system design at high pressure difference, high current density, high efficiency, fast response, small footprint, low temperature (20°C-90°C) operation, and high-purity oxygen byproduct. However, one of the main challenges of PEM water electrolysis is the high capital cost of the cell stack, including expensive acid-resistant stack hardware (such as Pt-coated Ti bipolar plates), expensive precious metal catalysts required for electrodes, and expensive PEMs.

[0005] Water electrolysis reaction: 2H2O→2H2+O2 (1)

[0006] Anodic oxidation reaction of PEMWE: 2 H2O→O2+4 H + +4 e - (2)

[0007] Cathodic reduction reaction of PEMWE: 2 H + +2 e - →H2 (3)

[0008] AEMWE is a developing technology. Figure 2 As shown, in the AEMWE system 200, the anode 205 and the cathode 210 are separated by a solid AEM electrolyte 215. Typically, a water feed 220 with an added electrolyte (such as diluted KOH or K2CO3 or deionized water) is fed to the cathode side. The anode and cathode catalysts typically include Ni-based or Ni alloy catalysts that do not contain platinum group metals. At the negatively charged cathode 210, water is reduced to form hydrogen 225 and hydroxyl ions by adding four electrons; the reaction is given by Equation 4. The hydroxyl ions diffuse from the cathode 210 to the anode 205 through the AEM 215 that conducts hydroxyl ions. At the positively charged anode 205, the hydroxyl ions are recombined into water and oxygen 230; the reaction is given by Equation 5. The AEM 215 not only conducts hydroxyl ions from the cathode 210 to the anode 205, but also separates H2 225 and O2 230 produced in the water electrolysis reaction. The AEM 215 allows the production of hydrogen 225 with a very high purity of at least 99.9% at high pressures of up to 35 bar.

[0009] Cathodic reduction reaction of AEMWE: 4 H2O+4 e - →2 H2+4 OH - (4)

[0010] Anodic oxidation reaction of AEMWE: 4 OH - →2 H2O+O2+4 e - (5)

[0011] AEMWE has advantages over PEMWE because it allows the use of cheaper platinum group metal-free catalysts, such as Ni and Ni alloy catalysts. In addition, much cheaper stainless steel bipolar plates can be used in the gas diffusion layer (GDL) of AEMWE instead of the expensive Pt-coated Ti bipolar plates currently used in PEMWE. However, the biggest obstacle to the development of AEM systems is the membrane hydroxyl ion conductivity and stability, as well as the lack of understanding of how to integrate catalysts into AEM systems. Research on AEMWE in the literature focuses on the development of electrocatalysts, AEMs, and understanding the operating mechanism, with the general goal of obtaining efficient, low-cost and stable AEMWE technology.

[0012] Fuel cells, which are the next generation of clean energy, convert the energy of chemical reactions such as oxidation / reduction redox reactions of hydrogen and oxygen into electrical energy. The three main types of fuel cells are alkaline electrolyte fuel cells, polymer electrolyte membrane fuel cells, and solid oxide fuel cells. Polymer electrolyte membrane fuel cells may include proton exchange membrane fuel cells (PEMFC), anion exchange membrane fuel cells (AEMFC), and direct methanol fuel cells. PEMFC uses PEM to conduct protons from the anode to the cathode, and it also separates H2 gas and O2 gas to prevent gas crossover. AEMFC uses AEM to conduct OH - It conducts from cathode to anode, and it also separates H2 gas and O2 gas to prevent gas crossover.

[0013] The anode in an electrochemical cell is an electrode whose main reaction is oxidation (e.g., a water oxidation / oxygen evolution reaction electrode for a water electrolyzer, or a hydrogen oxidation electrode for a fuel cell). The cathode in an electrochemical cell is an electrode whose main reaction is reduction (e.g., a proton reduction / hydrogen evolution reaction electrode for a water electrolyzer, or an oxygen reduction electrode for a fuel cell). The membrane is one of the key materials constituting an electrolyzer or a fuel cell, and is an important driving factor for safety and performance. Some important properties of membranes for fuel cells and membrane electrolysis include high conductivity, high ion permeability, high ion exchange capacity (for ion exchange membranes), high ion / H2 and O2 selectivity (low H2 and O2 permeability / crossover), low price, low area resistance to minimize efficiency loss caused by ohmic polarization, high tolerance to oxidation and reduction conditions, chemical inertness, high thermal stability, high proton conductivity, and high mechanical strength (thickness, low swelling) over a wide pH range.

[0014] For AEM water electrolysis and AEMFC to have widespread applications in renewable energy systems, significant advances are needed in cost-effective, high-performance, and stable catalysts, membrane materials, and other cell stack components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram of one embodiment of a PEMWE battery.

[0016] Figure 2 is a diagram of one embodiment of an AEMWE battery.

[0017] Figure 3 It is poly(triphenylene-co-phenanthrenylpiperidinium iodide) (abbreviated as PTPP-I)

[0018] Schematic representation of one embodiment of the synthesis of an anion exchange polymer. DETAILED DESCRIPTION

[0019] Novel anion exchange polymers comprising a plurality of repeating units of formula (I)

[0020]

[0021] Anion exchange polymers have been developed for the preparation of AEMs. Anion exchange polymers have a stable hydrophobic polymer backbone containing linear aromatic units (such as biphenyl and terphenyl) and polycyclic aromatic units (such as naphthalene and phenanthrene). Cationic groups, such as piperidinium, quaternized carbazole derivatives, quaternized phenothiazine derivatives, or piperidinium salts, are covalently introduced into the polymers for the preparation of novel AEMs. Therefore, these polymers provide high OH - Conductivity, high chemical stability, low swelling in alkaline water at 60°C to 120°C, and high mechanical stability. Anion exchange polymers can be used in electrolysis, such as water or CO2 electrolysis, and other uses such as redox flow batteries and fuel cell applications.

[0022] Anion exchange polymers are designed to achieve high OH by incorporating piperidinium, piperidinium salts, or both into the polymer side chains. - Conductivity; high chemical stability by having a polymer backbone without ether bonds; and high mechanical strength due to high polymer backbone rigidity and molecular weight by incorporating both linear aromatic units (such as biphenyl and terphenyl) and polycyclic aromatic units (such as naphthalene and phenanthrene) into the polymer backbone. The polymer has hydrophilic anion exchange functional groups (such as piperidinium functional groups) on the polymer side chains and a stable hydrophobic polymer backbone without ether bonds, the hydrophobic polymer backbone comprising linear aromatic units (such as biphenyl and terphenyl) and polycyclic aromatic units (such as naphthalene and phenanthrene), which enables efficient and stable operation in water or CO2 electrolysis, redox flow batteries and fuel cell applications.

[0023] One aspect of the present invention is an anion exchange polymer. In one embodiment, the polymer comprises a plurality of repeating units of formula (I)

[0024]

[0025] wherein Ar1 is selected from the group consisting of:

[0026]

[0027] and mixtures thereof;

[0028] Ar2 is selected from the group consisting of:

[0029]

[0030] and mixtures thereof;

[0031] X1 is selected from the group consisting of:

[0032]

[0033] Optionally and mixtures thereof;

[0034] Among them, Y1 - and Y2 - It is an anion;

[0035] Where R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0036] Where R 29 To R 31 are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0037] Where R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0038] Where A is O, S or NR 100 ;

[0039] Where R 100 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0040] wherein m is an integer from 5 to 500;

[0041] wherein n is an integer from 0 to 500, and the molar ratio of n / m is in the range of 0:1 to 20:1;

[0042] Where p is 1, 2, 3 or 4;

[0043] where q is 0, 1, 2, or 3; and

[0044] Where t is 1, 2, 3, 4, 5 or 6.

[0045] In some embodiments, Ar1 is selected from the group consisting of:

[0046]

[0047] and mixtures thereof;

[0048] Where R 25 , R 26 , R 27 and R 28 Each is independently -H or -CH3;

[0049] where p is 1 or 2; and

[0050] Where q is 0 or 1.

[0051] In some embodiments, Ar2 is selected from the group consisting of:

[0052]

[0053] and mixtures thereof.

[0054] In some embodiments, Ar2 is selected from the group consisting of:

[0055]

[0056] and mixtures thereof.

[0057] In some embodiments, X1 is

[0058]

[0059] And where R 30 and R 31 each independently is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; and

[0060] Among them, Y1 - HCO3 - OH - or I - .

[0061] In some embodiments, X1 is

[0062]

[0063] wherein t is 1, 2, 3, 4, 5 or 6; and

[0064] Among them, Y2 - HCO3 - OH - or I - .

[0065] In some embodiments, X1 is a mixture of

[0066]

[0067] Where R 30 and R 31 Each is independently -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2;

[0068] wherein t is 1, 2, 3, 4, 5 or 6; and

[0069] Among them, Y1 - and Y2 - Selected from HCO3 - OH - or I - .

[0070] In some embodiments, the polymer comprising a plurality of repeating units of formula (I) is formed by superacid-catalyzed polyhydroxyalkylation of monomers Ar1', Ar2' and X1', followed by a Menshutkin reaction, wherein Ar1' is selected from the group consisting of:

[0071]

[0072] and mixtures thereof;

[0073] Ar2' is selected from the group consisting of:

[0074]

[0075] and mixtures thereof; and

[0076] X1' is selected from the group consisting of:

[0077]

[0078] Optionally and mixtures thereof;

[0079] Among them, Y2 - It is an anion;

[0080] Where R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0081] Where R 29 and R 30are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0082] Where R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0083] Where A is O, S or NR 100 ;

[0084] Where R 100 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group;

[0085] Where p is 1, 2, 3 or 4;

[0086] where q is 0, 1, 2, or 3; and

[0087] Where t is 1, 2, 3, 4, 5 or 6.

[0088] In some embodiments, Ar1' is selected from the group consisting of:

[0089]

[0090] and mixtures thereof;

[0091] Where R 25 , R 26 , R 27 and R 28 Each is independently -H or -CH3;

[0092] where p is 1 or 2; and

[0093] Where q is 0 or 1.

[0094] In some embodiments, Ar2' is selected from the group consisting of:

[0095]

[0096] and mixtures thereof.

[0097] In some embodiments, wherein Ar2' is selected from the group consisting of:

[0098]

[0099] and mixtures thereof.

[0100] In some embodiments, X1' is

[0101]

[0102] And where R 30 It is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2.

[0103] In some embodiments, X1' is

[0104]

[0105] And wherein t is 1, 2, 3, 4, 5 or 6.

[0106] In some embodiments, X1' is a mixture of

[0107]

[0108] Where R 30 is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2;

[0109] And wherein t is 1, 2, 3, 4, 5 or 6.

[0110] An anion exchange polymer comprising a plurality of repeating units of formula (I) can be synthesized by two steps: 1) a superacid-catalyzed polyhydroxyalkylation reaction of monomers Ar1′ and Ar2′ with X1′ (such as p-terphenyl as Ar1′ and phenanthrene as Ar2′ with --N-methyl-4-piperidinone as X1′) to form a neutral precursor polymer; and 2) a Menshutkin reaction to convert the neutral precursor polymer having a functional group (such as a piperidine-based group) into an anion exchange polymer comprising a plurality of repeating units of formula (I) having an anion-conducting functional group (such as a piperidinium-based cationic group). Optionally, an anion exchange polymer comprising a plurality of repeating units of formula (I) (having anion-conducting functional groups such as piperidinium-based cationic groups and negatively charged halide ions or bicarbonate ions) is converted into an anion exchange polymer comprising a plurality of repeating units of formula (I) (having anion-conducting functional groups such as piperidinium-based cationic groups and negatively charged OH groups) by soaking the polymer in an alkaline solution before forming the polymer into a membrane. - ion).

[0111] The polyhydroxyalkylation reaction of monomers Ar1' and Ar2' with monomer X1' provides an anion exchange polymer having a polymer backbone without ether bonds, which achieves high chemical stability of the polymer. The incorporation of electron-rich monomers Ar1' and Ar2' into the anion exchange polymer provides a hydrophobic polymer backbone without ether bonds, and the incorporation of monomer X1' into the anion exchange polymer provides a piperidinium derivative or a piperidinium salt derivative anion conducting functional group or both, which helps to achieve a stable high OH - Conductivity. Incorporation of monomers Ar1' and Ar2' into anion exchange polymers provides polymers with high mechanical strength due to high polymer backbone rigidity and molecular weight. The combination of a hydrophobic polymer backbone with high mechanical strength, hydrophilic polymer side chains, and alkaline stable hydrophilic piperidinium cation groups provides an anion exchange polymer with high OH - New anion exchange polymers with high conductivity, high chemical stability, high mechanical strength and long-term performance stability.

[0112] The molar ratio of Ar1' monomer to Ar2' monomer may be in the range of 0: 1 to 20: 1, or in the range of 0: 1 to 10: 1, or in the range of 0: 1 to 5: 1. The molar ratio of X1' monomer to Ar1' monomer and Ar2' monomer may be in the range of 1.2: 1 to 1: 1.2, or in the range of 1.1: 1 to 1: 1.1, or in the range of 1.05: 1 to 1: 1.05.

[0113] The superacid-catalyzed polyhydroxy alkylation reaction can be carried out at -10°C to 50°C, or at -5°C to 30°C, or at -5°C to 25°C for 2h to 72h, or 10h to 48h, or 12h to 24h. Suitable superacid catalysts include, but are not limited to, trifluoromethanesulfonic acid (CF3SO3H (TFSA)), methanesulfonic acid (MSA), fluorosulfuric acid (FSO3H), or mixtures thereof. Solvents for polyhydroxy alkylation reactions are those that dissolve one or more of the monomers. Suitable solvents include, but are not limited to, dichloromethane, chloroform, trifluoroacetic acid (TFA), or mixtures thereof.

[0114] The Menshutkin reaction is used to react a neutral precursor polymer with an alkyl halide, or first with an alkyl amine and then with an alkyl halide to convert the neutral precursor polymer into an anion exchange polymer comprising a plurality of repeating units of formula (I) (which has linear aromatic units (such as biphenyl and terphenyl), polycyclic aromatic units (such as naphthalene and phenanthrene) and stable cation-conducting functional groups (such as piperidinium, quaternized carbazole derivatives, quaternized phenothiazine derivatives and piperidinium salts)). Suitable alkyl halides include, but are not limited to, iodoalkyls or bromalkyls. Suitable alkyl amines include, but are not limited to, trimethylamine or triethylamine. The Menshutkin reaction can be carried out at 10° C. to 80° C., or 20° C. to 30° C., for 2 h to 72 h, or 10 h to 48 h, or 12 h to 24 h. Solvents used in the Menshutkin reaction are those capable of dissolving the neutral precursor polymer. Suitable solvents include, but are not limited to, N-methylpyrrolidone (NMP), N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 1,3-dioxolane, or mixtures thereof.

[0115] Anion exchange polymers comprising a plurality of repeating units of formula (I) have a weight average molecular weight in the range of 10,000 Daltons to 1,000,000 Daltons, or in the range of 50,000 Daltons to 500,000 Daltons.

[0116] Another aspect of the present invention is an anion exchange membrane comprising the above-mentioned polymer. Anion exchange membrane can be used in a variety of applications, including but not limited to fuel cells, electrolyzers, flow batteries, electrodialyzers, waste metal recovery systems, electrocatalytic hydrogen production systems, desalination devices, water purifiers, wastewater treatment systems, ion exchangers or CO2 separators.

[0117] In some embodiments, the anion exchange membrane comprises a non-porous symmetrical dense membrane, a dense skin asymmetric membrane, a reinforced composite membrane, or a thin film composite membrane. "Dense" means that the membrane has no pores larger than 1 nm.

[0118] In some embodiments, the reinforced composite membrane or thin film composite membrane comprises a porous substrate membrane impregnated or coated with an anion exchange polymer. The porous substrate membrane is made of a polymer different from the anion exchange polymer.

[0119] In some embodiments, the nonporous symmetrical dense membrane, dense skin asymmetric membrane, reinforced composite membrane, or thin film composite membrane can be a flat sheet membrane.

[0120] In some embodiments, a nonporous symmetrical dense membrane anion exchange membrane is prepared using a method comprising the following steps: 1) dissolving an anion exchange polymer in a solvent to form a polymer casting solution; 2) casting the polymer casting solution on a nonporous substrate to form a uniform layer of the polymer casting solution; 3) drying the polymer casting solution layer at 50°C to 180°C, or 50°C to 120°C, or 80°C to 120°C to form a dried membrane on the nonporous substrate; and optionally 4) ion-exchanging the halide anions of the anion exchange polymer in the membrane with hydroxide ions, bicarbonate ions, carbonate ions, or a combination thereof to form a nonporous symmetrical dense membrane anion exchange polymer membrane. When the membrane is used in a desired application, the nonporous substrate is removed from the membrane. The solvent for dissolving the anion exchange polymer can be selected from, but not limited to, NMP, DMAC, DMF, DMSO, 1,3-dioxolane, or a mixture thereof. The nonporous substrate used to make the nonporous symmetrical dense membrane can be selected from, but not limited to, glass plate, polyolefin membrane, polyimide membrane, polyester membrane, or fluorocarbon-based polymer membrane, such as poly(tetrafluoroethylene) (PTFE) membrane and poly(vinylidene fluoride) (PVDF) membrane.

[0121] In some embodiments, a dense skin asymmetric anion exchange membrane is prepared using a method comprising the following steps: 1) preparing an anion exchange polymer membrane casting solution, the casting solution comprising an anion exchange polymer of formula (I), a solvent miscible with water and soluble in the anion exchange polymer, and a non-solvent that cannot dissolve the anion exchange polymer; 2) casting a layer of the anion exchange polymer membrane casting solution onto a supporting substrate; 3) evaporating the solvent and non-solvent from the surface of the coated layer, and then solidifying the coated polymer layer in a solidification bath to form a dense skin asymmetric membrane structure; 5) drying the membrane at 50°C to 150°C, or 50°C to 120°C, or 80°C to 120°C; and optionally 6) ion-exchanging the halide anions of the anion exchange polymer in the membrane with hydroxide ions, bicarbonate ions, carbonate ions, or a combination thereof to form a dense skin asymmetric anion exchange polymer membrane. In some embodiments, when the membrane is used in a desired application, the supporting substrate is removed from the membrane. In some embodiments, the support substrate is part of the final dense cortical asymmetric anion exchange polymer membrane. The support substrate may include polyolefins (such as polypropylene and polyethylene), polyesters, polyamides (such as nylon 6 and nylon 6,6), cellulose or fluorocarbon-based polymers (such as PTFE and PVDF). Solvents for preparing dense cortical asymmetric membranes include but are not limited to NMP, DMAC, DMF, DMSO, dioxane, 1,3-dioxolane and mixtures thereof. Non-solvents for preparing dense cortical asymmetric membranes include but are not limited to acetone, methanol, ethanol, tetrahydrofuran (THF), toluene, n-octane, n-decane, lactic acid, citric acid, isopropanol and mixtures thereof. The dense cortical asymmetric membrane may have a thin non-porous dense layer less than 500nm located on a microporous support layer.

[0122] In some embodiments, the reinforced composite anion exchange membrane is prepared using a method comprising the following steps: 1) dissolving an anion exchange polymer in a solvent to form a polymer solution; 2) impregnating a porous matrix support membrane with an anion exchange polymer via dip coating, soaking, spray coating, painting or other known conventional solution impregnation methods to fill the pores with the anion exchange polymer; 3) drying the impregnated membrane at 50°C to 150°C, or 50°C to 120°C, or 80°C to 120°C; and optionally 4) ion exchange with hydroxide ions, bicarbonate ions, carbonate ions or a combination thereof with the halide anions of the anion exchange polymer in the pores of the reinforced membrane to form a reinforced composite anion exchange membrane having interconnected anion exchange polymer domains in the porous matrix. Solvents for preparing thin film composite anion exchange membranes include, but are not limited to, NMP, DMAC, DMF, DMSO, dioxane, 1,3-dioxolane and mixtures thereof. The porous matrix should have good thermal stability (stable up to at least 120°C), high stability under high pH conditions (e.g., pH greater than 8), high tolerance to oxidative and reductive conditions (insoluble and no degradation under oxidative and reductive conditions), high mechanical strength (no dimensional changes under system operating conditions), and other factors determined by the operating conditions of the electrochemical reaction. The porous matrix must be chemically compatible with the electrochemical cell and meet the mechanical requirements of the cell stacking or winding assembly operation.

[0123] Suitable polymers for preparing porous substrates can be selected from, but not limited to, polyolefins (such as polyethylene and polypropylene), polyamides (such as nylon 6 and nylon 6,6), polyesters, cellulose acetate, polybenzimidazole, fluorocarbon-based polymers (such as PTFE and PVDF), polycarbonate, cellulose, or combinations thereof. These polymers provide a variety of properties such as, such as low cost, high stability in alkaline water, good mechanical stability, and ease of processing for porous substrate fabrication.

[0124] The porous matrix can be a nonwoven matrix or a woven matrix, and has a symmetrical porous structure or an asymmetrical porous structure. The porous matrix can be formed by direct air drying after electrostatic spinning, phase conversion membrane manufacturing method, or by solvent exchange method after phase conversion. The porous matrix can also be manufactured via dry processing of thermoplastic polyolefin or wet processing of thermoplastic olefin. The dry processing of thermoplastic polyolefin utilizes extrusion to make the polymer higher than its melting point and form it into a desired shape. Subsequent annealing and stretching processes can also be carried out to increase the crystallinity and orientation and size of the pores. The wet processing of polyolefin porous matrix is ​​carried out by mixing a mixture of hydrocarbon liquid or low molecular weight oil with polymer resin or polymer resin and inorganic nanoparticles in the molten phase. The molten mixture is extruded through a mold similar to a separator of dry processing. The thickness of the porous matrix can be in the range of 10 microns to 400 microns, or in the range of 10 microns to 200 microns, or in the range of 10 microns to 100 microns, or in the range of 20 microns to 100 microns. The pore size of the porous matrix may be in the range of 1 micron to 500 microns, or in the range of 10 microns to 200 microns, or in the range of 50 microns to 100 microns.

[0125] In some embodiments, a thin film composite anion exchange membrane is prepared using a method comprising the following steps: 1) dissolving an anion exchange polymer in a solvent to form a polymer coating solution; 2) coating a layer of the anion exchange polymer coating solution on one surface of a microporous support membrane via dip coating, meniscus coating, spin coating, casting, soaking, spraying, painting or other known conventional solution coating techniques. 3) drying the coated membrane at 50°C to 150°C, or 50°C to 120°C, or 80°C to 120°C; and optionally 4) ion exchanging the halide anions of the anion exchange polymer in the coating layer with hydroxide ions, bicarbonate ions, carbonate ions or a combination thereof to form a thin film composite anion exchange membrane. Solvents for preparing thin film composite anion exchange membranes include, but are not limited to, NMP, DMAC, DMF, DMSO, dioxane, 1,3-dioxolane and mixtures thereof. The microporous support membrane should have good thermal stability (stable up to at least 120°C), high stability under high pH conditions (e.g., pH greater than 8), high tolerance to oxidation and reduction conditions (insoluble and no performance degradation under oxidation and reduction conditions), high mechanical strength (no dimensional change under system operating conditions), and other factors determined by the operating conditions of the electrochemical reaction. The microporous support membrane must be chemically compatible with the electrochemical cell and meet the mechanical requirements of the cell stacking or winding assembly operation.

[0126] The polymer suitable for preparing the microporous support membrane can be selected from, but not limited to, polyolefins (such as polyethylene and polypropylene), polyamides (such as nylon 6 and nylon 6,6), polyesters, cellulose acetate, polybenzimidazole, fluorocarbon-based polymers (such as PTFE and PVDF), polycarbonates, cellulose, or combinations thereof. These polymers provide a variety of properties such as, such as low cost, high stability in alkaline water, good mechanical stability, and ease of processability for membrane manufacturing.

[0127] The microporous support film can have a symmetrical porous structure or an asymmetrical porous structure. The asymmetrical microporous support film can be formed by direct air drying after the phase inversion membrane manufacturing method, or by a solvent exchange method after the phase inversion. The microporous support film can also be manufactured by the dry processing of thermoplastic polyolefins or the wet processing of thermoplastic olefins. The dry processing of thermoplastic polyolefins utilizes extrusion to make the polymer higher than its melting point and form it into a desired shape. Subsequent annealing and stretching processes can also be carried out to increase the crystallinity and orientation and size of the micropores. The wet processing of polyolefin separators is carried out by mixing a mixture of hydrocarbon liquids or low molecular weight oils with polymer resins or polymer resins and inorganic nanoparticles in the molten phase. The molten mixture is extruded through a mold similar to the separator of the dry process. The thickness of the microporous support film can be in the range of 10 microns to 400 microns, or in the range of 10 microns to 200 microns, or in the range of 10 microns to 100 microns, or in the range of 20 microns to 100 microns. The pore size of the microporous membrane may be in the range of 10 nanometers to 50 micrometers, or in the range of 50 nanometers to 10 micrometers, or in the range of 0.2 micrometers to 1 micrometer.

[0128] Another aspect of the present invention is a membrane electrode assembly. In one embodiment, the membrane electrode assembly includes: an anion exchange membrane, the anion exchange membrane comprising the above polymer; an anode, the anode comprising an anode catalyst on a first surface of the anion exchange membrane; and a cathode, the cathode comprising a cathode catalyst on a second surface of the anion exchange membrane; and

[0129] In some embodiments, the membrane electrode assembly further comprises: an anode porous transport layer adjacent to the anode; and a cathode porous transport layer adjacent to the cathode. In some embodiments, the anode and cathode catalysts are electrocatalysts that do not contain platinum group metals (PGM). The anode and cathode catalysts are used for oxygen evolution reaction and hydrogen evolution reaction, respectively. The anode and cathode catalysts should have low cost, good conductivity, and good electrocatalytic activity and stability. Suitable cathode catalysts may be selected from, but are not limited to, Ni-based alloys (such as Ni-Mo, Ni-Al, Ni-Cr, Ni-Sn, Ni-Co, Ni-W, and Ni-Al-Mo), metal carbides (such as Mo2C), metal phosphides (such as CoP), metal dichalcogenides (such as MoSe2), and mixtures thereof. Suitable anode catalysts may be selected from, but are not limited to, Ni-Fe alloys, Ni-Mo alloys, spinel Cu x Co 3x O3, Ni-Fe layered binary hydroxide nanoplates on carbon nanotubes, immobilized metal catalysts on conductive supports, and mixtures thereof.

[0130] In some embodiments, the anode comprising an anode catalyst on the first surface of the anion exchange membrane is formed by coating an anode catalyst ink on the first surface of the anion exchange membrane via meniscus coating, doctor blade coating, spray coating, painting or other known conventional ink coating techniques, followed by drying the coated anion exchange membrane.

[0131] In some embodiments, the cathode comprising a cathode catalyst on the second surface of the anion exchange membrane is formed by coating the cathode catalyst ink on the second surface of the anion exchange membrane via meniscus coating, doctor blade coating, spray coating, painting or other known conventional ink coating techniques, followed by drying the coated anion exchange membrane.

[0132] In some embodiments, the anode catalyst ink comprises an anode catalyst, OH as a binder, - In some embodiments, the cathode catalyst ink comprises a cathode catalyst, an OH group as a binder, - Exchange ionomer and solvent. OH - The exchange of ionomer binders generates OH between the reactive sites in the membrane and the electrode. - transport channels, thus greatly improving the utilization of electrocatalyst particles while reducing internal resistance. - The ion exchange polymer binder may have a chemical structure similar to the anion exchange polymers described above, such that the binder will achieve low interfacial resistance and similar swelling upon contact with water to avoid catalyst delamination, but maintain OH -Conductivity and high oxygen and hydrogen permeability. The solvent may be selected from, but not limited to, water, alcohol or mixtures thereof.

[0133] The anode porous transport layer and the cathode porous transport layer simultaneously transport electrons, heat and products with minimal voltage, current, heat, interface and fluid losses. The cathode porous transport layer may be made of, but not limited to, stainless steel, titanium mesh, titanium felt, titanium foam or a carbon-based material such as non-woven carbon paper, non-woven carbon cloth or woven carbon cloth. The anode porous transport layer may be made of, but not limited to, stainless steel, titanium mesh, titanium felt or titanium foam.

[0134] Example

[0135] Example 1: Synthesis of poly(triphenylene-co-phenanthrenylpiperidine) polymer (abbreviated as PTPP)

[0136] Terphenyl (10.36g, 45mmol), phenanthrene (0.89g, 5mmol) and 1-methyl-4-piperidone (6.22g, 55mmol) are mixed with 40mL of dichloromethane, and are cooled to 0 ℃ in ice water.Under stirring, trifluoroacetic acid (6mL) and trifluoromethanesulfonic acid (40mL) are added dropwise continuously in the stirred mixture.The mixture is stirred for 11 hours, while remaining at 0 ℃.The reaction mixture is blended with 1L of water to produce slurry.The slurry is filtered and rinsed with 1L of water, and then the filter cake is immersed in the water of 1L containing the sodium hydroxide of 5g and spends the night.The mixture is filtered again, and the filter cake is washed with water until pH is neutral.Then the solid obtained is dried overnight at 60 ℃, and then dried overnight under vacuum at 80 ℃.

[0137] Example 2: Synthesis of poly(triphenylene-co-phenanthrenylpiperidinium iodide) (abbreviated as PTPP-I)

[0138] The obtained PTPP polymer (50 mmol of piperidine units) was dissolved in 160 mL of dimethyl sulfoxide containing 4 mL of trifluoroacetic acid. To the solution, iodomethane (150 mmol) and anhydrous potassium carbonate (180 mmol) were added. The mixture was stirred for 24 hours while being shielded from light. The reaction mixture was poured into 1 L of ethyl acetate. The obtained mixture was filtered, and the filter cake was washed with 500 mL of ethyl acetate and water until the pH was neutral. The obtained solid was dried overnight at 60 ° C.

[0139] Example 3: Poly(triphenylene-co-phenanthrenylpiperidinium hydroxide) (abbreviated as PTPP-OH) anionic crosslinking Preparation of polymer membranes

[0140] The PTPP-1 anion exchange polymer membrane was prepared by dissolving PTPP-1 anion exchange polymer (5.0 g) in DMSO (20 g), casting the solution on a clean substrate, and drying at 60° C. overnight. The membrane was peeled off from the substrate and further dried in a vacuum oven at 100° C. for 48 h. The membrane was ion exchanged in 1 M KOH aqueous solution for 10 h to replace the I - The anionic PTPP-1 anion exchange polymer was converted into an OH - An anion exchange polymer of anions was prepared to form a poly(triphenylene-co-phenanthrenylpiperidinium hydroxide) anion exchange polymer membrane (abbreviated as PAPP-OH membrane). The in-plane hydroxide conductivity of the PAPP-OH membrane was 124.7 mS / cm at room temperature.

[0141] Specific implementation plan

[0142] While the following is described in conjunction with specific embodiments, it should be understood that this description is intended to illustrate and not to limit the scope of the foregoing description and the appended claims.

[0143] A first embodiment of the present invention is an anion exchange polymer comprising a plurality of repeating units of formula (I) Wherein Ar1 is selected from

[0144] And the group consisting of mixtures thereof; Ar2 is selected from

[0145] And mixtures thereof; X1 is selected from Optionally And mixtures thereof; wherein Y1 - and Y2 - is an anion; wherein R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein R 29 To R 31 are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein A is O, S or NR100 ; where R 100 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, alkenyl group, alkynyl group or aryl group is optionally substituted with a halide or a positively charged functional group; wherein m is an integer from 5 to 500; wherein n is an integer from 0 to 500, and the molar ratio of n / m is in the range of 0:1 to 20:1; wherein p is 1, 2, 3 or 4; wherein q is 0, 1, 2 or 3; and wherein t is 1, 2, 3, 4, 5 or 6. An embodiment of the present invention is one, any one or all of the previous embodiments in this paragraph up to the first embodiment in the paragraph, wherein Ar1 is selected from the group consisting of:

[0146]

[0147] and mixtures thereof; wherein R 25 , R 26 , R 27 and R 28 Each is independently -H or -CH3; wherein p is 1 or 2; and wherein q is 0 or 1. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein Ar2' is selected from

[0148] And a group consisting of mixtures thereof. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein Ar2' is selected from And a group consisting of mixtures thereof. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1 is And where R 30 and R 31 Each is independently -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; and wherein Y1 - HCO3 - OH - or I - The embodiments of the present invention are one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1 is wherein t is 1, 2, 3, 4, 5 or 6; and wherein Y2 - HCO3 - OH - or I- . Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1 is A mixture of R 30 and R 31 Each is independently -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; wherein t is 1, 2, 3, 4, 5 or 6; and wherein Y1 - , and Y2 - Selected from HCO3 - OH - or I - Embodiments of the invention are one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein the anion exchange polymer is synthesized from monomers Ar1', Ar2' and X1', wherein Ar1' is selected from And the group consisting of mixtures thereof; Ar2' is selected from

[0149]

[0150] and mixtures thereof; and X1' is selected from Optionally And mixtures thereof; wherein Y2 - is an anion; wherein R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein R 29 and R 30 are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein A is O, S or NR 100 ; where R 100wherein Ar is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and the alkyl group, alkenyl group, alkynyl group, or aryl group is optionally substituted with a halide or a positively charged functional group; wherein p is 1, 2, 3, or 4; wherein q is 0, 1, 2, or 3; and wherein t is 1, 2, 3, 4, 5, or 6. Embodiments of the invention are one, any, or all of the prior embodiments in this paragraph up to the first embodiment in this paragraph, wherein Ar is selected from And mixtures thereof; wherein R 25 , R 26 , R 27 and R 28 Each is independently -H or -CH3; wherein p is 1 or 2; and wherein q is 0 or 1. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein Ar2' is selected from And a group consisting of mixtures thereof. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein Ar2' is selected from And a group consisting of mixtures thereof. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1' is And where R 30 is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2. Embodiments of the present invention are one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1 is and wherein t is 1, 2, 3, 4, 5 or 6. Embodiments of the invention are one, any or all of the previous embodiments in this paragraph up to the first embodiment in this paragraph, wherein X1 is A mixture of R 30 is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; and wherein t is 1, 2, 3, 4, 5 or 6.

[0151] The second embodiment of the present invention is an anion exchange membrane comprising an anion exchange polymer of the first embodiment. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the second embodiment in this paragraph, wherein the anion exchange membrane is used in a fuel cell, an electrolyzer, a flow battery, an electrodialyzer, a waste metal recovery system, an electrocatalytic hydrogen production system, a desalinator, a water purifier, a wastewater treatment system, an ion exchanger or a CO2 separator. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the second embodiment in this paragraph, wherein the anion exchange membrane comprises a non-porous symmetrical dense membrane, a dense skin asymmetric membrane, a reinforced composite membrane or a thin film composite membrane. An embodiment of the present invention is one, any or all of the previous embodiments in this paragraph up to the second embodiment in this paragraph, wherein the dense skin asymmetric membrane, the reinforced composite membrane or the thin film composite membrane comprises a porous substrate material impregnated or coated with an anion exchange polymer.

[0152] A third embodiment of the present invention is a membrane electrode assembly comprising an anion exchange membrane comprising the anion exchange polymer of the first embodiment; an anode comprising an anode catalyst on a first surface of the anion exchange membrane; and a cathode comprising a cathode catalyst on a second surface of the anion exchange membrane.

[0153] Although there is no further detailed description, it is believed that those skilled in the art can utilize the present invention to the greatest extent by using the foregoing description and can easily determine the essential characteristics of the present invention without departing from the spirit and scope of the present invention to make various changes and modifications of the present invention and adapt it to various usages and conditions. Therefore, the aforementioned preferred specific embodiments should be understood as merely illustrative and not to limit the rest of the present disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0154] In the foregoing, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. An anion exchange polymer comprising a plurality of repeating units of formula (I) wherein Ar1 is selected from the group consisting of: and mixtures thereof; Ar2 is selected from the group consisting of: and mixtures thereof; X1 is selected from the group consisting of: Optionally and mixtures thereof; Among them, Y1 - and Y2 - It is an anion; Where R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where R 29 To R 31 are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where A is O, S or NR 100 ; Where R 100 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; wherein m is an integer from 5 to 500; wherein n is an integer from 0 to 500, and the molar ratio of n / m is in the range of 0:1 to 20:1; Where p is 1, 2, 3 or 4; where q is 0, 1, 2, or 3; and Where t is 1, 2, 3, 4, 5 or 6.

2. The anion exchange polymer according to claim 1, wherein Ar1 is selected from the group consisting of: and mixtures thereof; Where R 25 , R 26 , R 27 and R 28 Each is independently -H or -CH3; where p is 1 or 2; and Where q is 0 or 1.

3. The anion exchange polymer according to any one of claims 1 to 2, wherein Ar2 is selected from the group consisting of: and mixtures thereof.

4. An anion exchange polymer according to any one of claims 1 to 2, wherein X1 is And where R 30 and R 31 each independently is -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; and Among them, Y1 - HCO3 - OH - or I - .

5. An anion exchange polymer according to any one of claims 1 to 2, wherein X1 is wherein t is 1, 2, 3, 4, 5 or 6; and Among them, Y2 - HCO3 - OH - or I - .

6. An anion exchange polymer according to any one of claims 1 to 2, wherein X1 is a mixture of Where R 30 and R 31 Each is independently -H, -CH3, -CH2CH3, -CH(CH3)2, -C(CH3)3, -CH2-C6H5 or -CH2-CH(CH3)2; wherein t is 1, 2, 3, 4, 5 or 6; and Among them, Y1 - and Y2 - Selected from HCO3 - OH - or I - .

7. The anion exchange polymer according to any one of claims 1 to 2, wherein the anion exchange polymer is synthesized from monomers Ar1', Ar2' and X1', wherein Ar1' is selected from the group consisting of: and mixtures thereof; Ar2' is selected from the group consisting of: and mixtures thereof; and X1' is selected from the group consisting of: Optionally and mixtures thereof; Among them, Y2 - It is an anion; Where R1 to R 28 are each independently hydrogen, a halide, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where R 29 and R 30 are each independently hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where R 32 is an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where A is O, S or NR 100 ; Where R 100 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group or an aryl group, and the alkyl group, the alkenyl group, the alkynyl group or the aryl group is optionally substituted with a halide or a positively charged functional group; Where p is 1, 2, 3 or 4; where q is 0, 1, 2, or 3; and Where t is 1, 2, 3, 4, 5 or 6.

8. An anion exchange membrane comprising the anion exchange polymer according to any one of claims 1 to 2.

9. The anion exchange membrane of claim 8, wherein the anion exchange membrane comprises a dense skin asymmetric membrane, a reinforced composite membrane or a thin film composite membrane or a non-porous symmetrical dense membrane, wherein the dense skin asymmetric membrane, the reinforced composite membrane or the thin film composite membrane comprises a porous substrate material impregnated or coated with the anion exchange polymer.

10. A membrane electrode assembly comprising: An anion exchange membrane comprising an anion exchange polymer according to any one of claims 1 to 2; an anode comprising an anode catalyst on a first surface of the anion exchange membrane; and a cathode comprising a cathode catalyst on a second surface of the anion exchange membrane; Optionally, an anode porous transport layer adjacent to the anode; and Optionally, a cathode porous transport layer adjacent to the cathode.

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