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CN-121975167-A - AEM alkaline anion exchange membrane with high conductivity and preparation method thereof

CN121975167ACN 121975167 ACN121975167 ACN 121975167ACN-121975167-A

Abstract

The invention discloses a high-conductivity alkaline anion exchange membrane and a preparation method thereof, wherein the membrane is prepared from a rigid aromatic monomer, reactive quaternized polyarylethersulfone, immobilized quaternary ammonium salt, hydrophobic mesoporous SiO 2 and a cross-linking agent, and a cation density gradient transition layer and an anti-corrosion coating are arranged on the surface of the membrane. The membrane promotes alkali resistance stability through covalent bonding quaternary ammonium and a three-dimensional crosslinking structure, mesoporous SiO 2 regulates and controls swelling and builds an ion channel, and the gradient structure reduces interface contact resistance. OH ‑ conductivity reaches 149-168mS/cm at 80 ℃, alkali-resistant retention rate is more than or equal to 90% in 4000 hours, in-plane swelling rate is less than or equal to 5.1%, the interface contact resistance is as low as 0.08Ω & cm 2 , has high conductivity, low swelling, high alkali resistance and excellent interface compatibility, and is suitable for alkaline fuel cells.

Inventors

  • LIU XIANG
  • GUO ZHENBO

Assignees

  • 苏州工业园区和顺电气股份有限公司

Dates

Publication Date
20260505
Application Date
20260403

Claims (7)

  1. 1. The AEM alkaline anion exchange membrane with high conductivity is characterized by being prepared from the following raw materials in parts by weight: 30-40 parts of rigid aromatic monomer, 10-15 parts of quaternized modified polyarylethersulfone containing reactive end groups, 15-25 parts of immobilized quaternary ammonium compound, 1-3 parts of surface hydrophobic modified mesoporous SiO 2 nanospheres, 2-5 parts of anhydride cross-linking agent, 100-150 parts of green aprotic solvent, 6-8 parts of alkali-resistant cationic monomer, 2-4 parts of alkali-resistant cationic polymer, 1-2 parts of alkali-resistant reinforced micro powder, 0.1-0.5 part of free radical initiator, 4-6 parts of alkali-resistant polymer and 1-2 parts of conductive filler as transition layer raw materials; The polymer matrix of the alkaline anion exchange membrane is formed by nucleophilic substitution copolymerization of a rigid aromatic monomer and quaternized modified polyarylethersulfone containing a reactive end group to form a copolymer main chain containing an active side group, and then a three-dimensional crosslinked network is formed by bonding functionalization of an immobilized quaternary ammonium compound and crosslinking of an anhydride crosslinking agent, and the transition layer is formed into a cationic density gradient structure by in-situ polymerization.
  2. 2. The high conductivity AEM basic anion exchange membrane according to claim 1, wherein the rigid aromatic monomer is selected from one or more of 1,1' -bi-2-naphthol, 2' -dihydroxy-1, 1' -binaphthyl and 1,3, 5-tris (4-hydroxyphenyl) benzene, and the supported quaternary ammonium compound is selected from one or two of 3-chloro-2-hydroxypropyl trimethylammonium chloride and didodecyl dimethylammonium chloride.
  3. 3. The AEM alkaline anion exchange membrane with high conductivity according to claim 1, wherein the alkali-resistant cationic monomer is selected from one or more of acryloyloxyethyl trimethyl ammonium chloride, (3-acrylamidopropyl) trimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride, the alkali-resistant cationic polymer is selected from one or more of polydiallyl dimethyl ammonium chloride, polyquaternium-7 and polyquaternium-10, the free radical initiator is selected from one or more of ammonium persulfate, potassium persulfate and tert-butyl hydroperoxide, and the alkali-resistant reinforcing micro powder is selected from one or more of nano zirconium oxide, nano titanium oxide and nano montmorillonite.
  4. 4. The high conductivity AEM basic anion exchange membrane according to claim 1, wherein the anhydride cross-linking agent is selected from one or more of pyromellitic dianhydride, trimellitic anhydride and maleic anhydride, and the green aprotic solvent is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide.
  5. 5. The high conductivity AEM basic anion exchange membrane according to claim 1, wherein the alkali-resistant polymer in the corrosion-resistant coating is selected from one or more of polyphenylene oxide, polyethersulfone and polyvinylidene fluoride, and the conductive filler is selected from one or more of carbon nanotubes, graphene and conductive carbon black.
  6. 6. The highly conductive AEM basic anion exchange membrane according to claim 1, wherein the mass ratio of alkali resistant cationic monomer to alkali resistant cationic polymer in the cation density gradient transition layer is 3:1-2:1, the membrane having an OH - conductivity of 100-180mS/cm at 80 ℃.
  7. 7. A method for preparing a high-conductivity AEM alkaline anion exchange membrane, which is used for preparing the high-conductivity AEM alkaline anion exchange membrane according to any one of claims 1 to 6, and is characterized by comprising the following specific preparation steps: S1, dissolving a rigid aromatic monomer and quaternized modified polyarylethersulfone containing a reactive end group in a green aprotic solvent according to the weight portion ratio, stirring and reacting for 4-8 hours at 200-400rpm and 80-100 ℃, and carrying out nucleophilic substitution copolymerization to obtain a copolymer solution containing an active side group; s2, adding an immobilized quaternary ammonium compound into the copolymer solution, carrying out heat preservation reaction for 2-4 hours at the temperature of 60-70 ℃ at 200-300rpm to carry out bonding functionalization, adding an anhydride cross-linking agent, and continuously stirring and reacting for 3-6 hours at the temperature of 90-110 ℃ to form a three-dimensional cross-linked network matrix solution; s3, adding surface hydrophobic modified mesoporous SiO 2 nanospheres into a matrix solution, performing ultrasonic dispersion for 30-60min, forming a film by adopting a tape casting method, and performing vacuum drying at 60-80 ℃ for 12-24h to obtain a matrix film body; S4, dissolving alkali-resistant cationic monomers, alkali-resistant cationic polymers, alkali-resistant reinforced micro powder and free radical initiator in a green aprotic solvent, stirring at 200-300rpm for 10-20min to prepare a transition layer liquid, coating the transition layer liquid on the surface of a base film by a gradient coating process, and preserving heat for 2-4h at 60-85 ℃ to initiate in-situ polymerization to form a cationic density gradient transition layer; S5, dissolving the alkali-resistant polymer and the conductive filler in a green aprotic solvent, stirring at 300-500rpm for 20-30min to prepare an anti-corrosion coating liquid, coating the anti-corrosion coating liquid on the contact area of the membrane edge only by a mask dip-coating process, and drying in vacuum at 70-90 ℃ for 6-12h for curing to obtain the AEM alkaline anion exchange membrane.

Description

AEM alkaline anion exchange membrane with high conductivity and preparation method thereof Technical Field The invention relates to the field of high-performance materials, in particular to a high-conductivity AEM alkaline anion exchange membrane and a preparation method thereof. Background An alkaline Anion Exchange Membrane (AEM) is a core component of an energy device such as a fuel cell, electrolyzed water, etc., and its performance directly determines the energy conversion efficiency and service life of the device. The existing AEM has three general technical bottlenecks, namely, the OH - conductivity and the mechanical stability are difficult to be compatible, the quaternized polymer matrix is easy to degrade in an alkaline environment, the membrane is seriously swelled due to high ion exchange capacity, the interface impedance of the membrane and the electrode is large, the compatibility of the traditional homogeneous membrane and a catalytic layer is poor, the charge transfer efficiency is low, and the edge area is easy to be corroded by electrolyte, so that the problem of delamination and damage occurs after long-term operation. In order to solve the above problems, the prior art is optimized by single modification means, such as physical blending of inorganic filler to improve stability or improving quaternary ammonium group content to enhance conductivity, but none of the prior art breaks through the dilemma of synergistic optimization of "conduction-stability-interface". In addition, the transition layer is designed to be of a homogeneous structure, interface impedance cannot be reduced through gradient regulation and control, and quaternary ammonium groups are easy to fall off, so that performance is attenuated. Therefore, developing an AEM with high OH - conductivity, excellent alkali resistance stability and low interface resistance is a critical issue to be addressed in the industry. Disclosure of Invention Aiming at the problems, the invention provides the AEM alkaline anion exchange membrane with high conductivity and the preparation method thereof, and the AEM alkaline anion exchange membrane has excellent conductivity, alkali resistance stability and long-term use property, simultaneously has excellent corrosion resistance, mechanical strength, swelling property and the like, and can meet the application requirements of alkaline water electrolysis hydrogen production and other severe electrochemical environments. In order to achieve the above purpose, the present invention adopts the following technical scheme: a highly conductive AEM basic anion exchange membrane, which is prepared from the following raw materials in parts by weight: 30-40 parts of rigid aromatic monomer, 10-15 parts of quaternized modified polyarylethersulfone containing reactive end groups, 15-25 parts of immobilized quaternary ammonium compound, 1-3 parts of surface hydrophobic modified mesoporous SiO 2 nanospheres, 2-5 parts of anhydride cross-linking agent, 100-150 parts of green aprotic solvent, 6-8 parts of alkali-resistant cationic monomer, 2-4 parts of alkali-resistant cationic polymer, 1-2 parts of alkali-resistant reinforced micro powder, 0.1-0.5 part of free radical initiator, 4-6 parts of alkali-resistant polymer and 1-2 parts of conductive filler as transition layer raw materials; The polymer matrix of the alkaline anion exchange membrane is formed by nucleophilic substitution copolymerization of a rigid aromatic monomer and quaternized modified polyarylethersulfone containing a reactive end group to form a copolymer main chain containing an active side group, and then a three-dimensional crosslinked network is formed by bonding functionalization of an immobilized quaternary ammonium compound and crosslinking of an anhydride crosslinking agent, and the transition layer is formed into a cationic density gradient structure by in-situ polymerization. Optionally, the rigid aromatic monomer is selected from one or more of 1,1' -bi-2-naphthol, 2' -dihydroxyl-1, 1' -binaphthyl and 1,3, 5-tri (4-hydroxyphenyl) benzene, and the immobilized quaternary ammonium compound is selected from one or two of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride and didodecyl dimethyl ammonium chloride. The alkali-resistant cationic monomer is selected from one or more of acryloyloxyethyl trimethyl ammonium chloride, (3-acrylamide propyl) trimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride, the alkali-resistant cationic polymer is selected from one or more of polydiallyl dimethyl ammonium chloride, polyquaternary ammonium salt-7 and polyquaternary ammonium salt-10, the free radical initiator is selected from one or more of ammonium persulfate, potassium persulfate and tert-butyl hydroperoxide, and the alkali-resistant reinforced micro powder is selected from one or more of nano zirconium oxide, nano titanium oxide and nano montmorillonite. Optionally, the anhydride cross-linking agent is selected f