A porous substrate reinforced anion exchange membrane, and a preparation method and application thereof

Abstract

The application discloses a porous substrate reinforced anion exchange membrane and a preparation method and application thereof, relates to the technical field of anion exchange membranes, and discloses a porous substrate reinforced anion exchange membrane which is obtained by uniformly mixing a polyarylene alkylidene cationic polymer solution and a C1-C10 alcohol solvent, coating the mixture on both sides of a porous substrate, and removing the solvent. The application does not need to pretreat the porous substrate, can realize good infiltration of the cationic polymer solution to the porous substrate, and further obtains a porous substrate reinforced anion exchange membrane with a sandwich structure. The thin film has outstanding anti-swelling property and excellent mechanical property, and has good electrochemical performance, and has a good application prospect in an alkaline membrane energy conversion device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anion exchange membrane, and particularly relates to a porous substrate reinforced anion exchange membrane and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen energy has the advantages of high energy density and zero pollution, and its use and development is one of the most feasible ways to solve energy and environmental problems. As an important carrier of hydrogen energy use and development, anion exchange membrane fuel cell (AEMFC) and anion exchange membrane water electrolysis (AEMWE) have the potential advantages of using non-precious metal catalysts and low-cost accessories due to the alkaline working environment, and are an important direction for future hydrogen energy conversion.

[0003] As a key material of AEMFC and AEMWE, it is of great significance to develop anion exchange membranes with excellent mechanical properties, anti-swelling and mechanical durability. Good mechanical properties can ensure the smooth progress of anion exchange membranes from the preparation of membrane electrodes to the assembly and operation of devices. At present, due to the high ion content of cationic polymers, the water absorption swelling of the cationic polymers in the hydrated state is too high, which causes most AEMs to exhibit low tensile strength and mechanical durability. Using a porous substrate to reinforce the cationic polymer is an effective strategy. The addition of the porous substrate as a support can improve the mechanical properties of the AEM as a whole, and the cationic polymer filled in the microporous fiber is constrained by the substrate, and the swelling will be effectively inhibited. However, the cationic polymer is usually a hydrophilic compound, and the commonly used porous substrate (such as polyethylene, expanded polytetrafluoroethylene, polyphenylene sulfide, polyether ether ketone, etc.) is a hydrophobic material, and the compatibility of the two is poor. In the reported preparation process, the porous reinforcing substrate has been pretreated in advance by using solvents such as ethanol and propanol to improve its hydrophilicity, but this strategy increases the film preparation process, and the rapid evaporation of the alcohol solvent can easily cause the hydrophilic treatment to fail. SUMMARY

[0004] The present application aims to provide a porous substrate reinforced anion exchange membrane and a preparation method and application thereof. A cheap porous base film is used as a reinforcing substrate, and a polyarylene alkylene type cationic polymer is used as a filled electrolyte to prepare a sandwich-structured reinforced anion exchange membrane. The feature of the present application is that a polyarylene alkylene type cationic polymer is selected as an electrolyte, and the anion exchange membrane prepared therefrom has excellent alkali stability and ionic conductivity, but its dimensional stability needs to be improved. After being reinforced by the substrate, the porous substrate reinforced anion exchange membrane not only retains the excellent alkali stability and ionic conductivity of the original membrane, but also has significantly improved dimensional stability and mechanical properties due to the constraint and reinforcement of the porous substrate.

[0005] The present application provides a porous substrate reinforced anion exchange membrane, the anion exchange membrane has a sandwich-like structure, which comprises a porous substrate arranged in the middle and cationic polymers arranged on the top and bottom, and the internal voids of the porous substrate are filled with the cationic polymers.

[0006] Preferably, the molecular structure of the cationic polymer is as follows:

[0007]

[0008] wherein n represents the degree of polymerization, n is an integer between 10-1,000,000;

[0009] The Ar fragment is independently selected from the disubstituted fragment Ar1 and the polysubstituted fragment Ar2, and the molar ratio of the Ar2 fragment to the Ar1 fragment is r, and 0≤r≤1.0;

[0010] Ar1 is independently selected from one or more of the following structures:

[0011]

[0012] Ar2 is independently selected from one or more of the following structures:

[0013]

[0014] R 1 The hydrogen atom, the hydrocarbon group containing carbon atoms between 1-20 or the alkyl group containing carbon atoms between 1-6 which is completely or partially fluorinated is independently selected;

[0015] k=0 or 1; x=0-12;

[0016] Z is independently selected from one or more of the H atom, the quaternary ammonium cation and the cation containing a nitrogen heterocycle.

[0017] Preferably, the quaternary ammonium cation has the following formula:

[0018]

[0019] wherein R 2 -R 7 is independently selected from the hydrocarbon group containing carbon atoms between 1-20, and in addition R 2 and R 6 may be connected to each other between the molecular chains or within the molecular chains; J=0-3; the counterion A - is selected from one or more of the halide ion, the methyl sulfate ion, the hydroxide ion or the bicarbonate ion.

[0020] Preferably, the nitrogen-containing heterocyclic cation comprises one or more of partially or fully substituted pyrazole, pyrrole, piperidine, imidazole and quinuclidine cations, having the following structure:

[0021]

[0022] wherein R 81r -R 810 are independently selected from hydrocarbyl groups having a carbon number of 1-20, counterion A - is selected from one or more of halide, methyl sulfate, hydroxide or bicarbonate.

[0023] The preparation steps of the porous substrate reinforced anion exchange membrane are as follows:

[0024] S1, dissolving the cationic polymer in a first organic solvent to obtain a first cationic polymer solution;

[0025] S2, adding a second organic solvent to the first cationic polymer solution obtained in S1, and mixing uniformly to obtain a second cationic polymer solution containing a co-solvent;

[0026] S3, coating the second cationic polymer solution containing a co-solvent obtained in S2 on a substrate to perform coating;

[0027] S4, laying a porous substrate on the surface of the coated substrate obtained in S3, and drying to obtain a single-side coated anion exchange membrane;

[0028] S5, coating a second cationic polymer solution on the surface of the single-side coated anion exchange membrane obtained in S4, removing the solvent in the drying tunnel, and peeling off after drying to obtain a porous substrate reinforced anion exchange membrane.

[0029] Preferably, the first organic solvent used in S1 is at least one of polar aprotic solvents such as dimethyl sulfoxide, N-methyl pyrrolidone, N,N-dimethylacetamide or N,N-dimethylformamide; and the second organic solvent used in S2 is at least one of C1-C10 alcohol solvents.

[0030] Preferably, the second organic solvent is added in an amount of 10-150wt% of the first cationic polymer solution; and the solid content of the first cationic polymer solution is 10-40wt%.

[0031] Preferably, the coating method used in S3 and S5 includes at least one of slot coating, doctor blade, wire bar, and micro-recess coating, and the coating thickness is 8-500μm.

[0032] Preferably, the porous substrate used in S4 is at least one of polyethylene, polypropylene, expanded polytetrafluoroethylene, expanded polyvinylidene fluoride, polyphenylene sulfide, polyether ether ketone or nylon, and the thickness thereof ranges from 3 to 100 μm.

[0033] The application provides an application of the above-mentioned porous substrate reinforced anion exchange membrane in an alkaline membrane energy conversion device.

[0034] Therefore, the application provides a porous substrate reinforced anion exchange membrane, a preparation method and an application thereof, and has the following beneficial effects:

[0035] 1. The application uses a polyarylene alkylidene type cationic polymer, which has high ion conductivity and good alkaline stability, so that the reinforced membrane obtained after the porous substrate is reinforced still has good electrochemical performance and chemical stability;

[0036] 2. The compatibility of the porous substrate and the cationic polymer solution is improved by adding a C1-C10 alcohol solvent to the cationic polymer solution, so that the cationic polymer solution can be well infiltrated and filled into the porous substrate, the film preparation process in actual production is simplified, and large-scale production is suitable; and the addition of the alcohol solvent with low boiling point reduces the use of high-boiling-point solvents such as N,N-dimethylformamide and dimethyl sulfoxide in the initial film coating solution, facilitates subsequent solvent recovery and drying processes, and effectively reduces production costs.

[0037] 3. The three-layer composite membrane prepared by the above preparation method has the same thickness of the upper and lower layers, which is convenient for subsequent film production and assembly.

[0038] 4. After being reinforced by the porous substrate, the composite membrane has higher mechanical strength and dimensional stability.

[0039] 5. The reinforced membrane reduces the amount of cationic polymer used, and has good cost-effectiveness.

[0040] 6. The porous substrate reinforced anion exchange membrane prepared by the application can be used in alkaline membrane fuel cells, water electrolysis and many other fields. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 FIG. 1 is a SEM diagram of the anion exchange membrane in Example 1 of the application;

[0042] Figure 2 FIG. 3 is a curve diagram of the variation of the hydroxyl ion conductivity of the anion exchange membrane two in Example 1 and Comparative Example 1 with temperature;

[0043] Figure 3 FIG. 5 is a curve diagram of the variation of the water absorption rate of the anion exchange membrane one in Example 1 and Comparative Example 1 with temperature;

[0044] Figure 4 Figure 1 is a graph showing the change of swelling rate of the anion exchange membrane one in Example 1 and Comparative Example 1 with temperature;

[0045] Figure 5 Figure 2 is a graph showing the comparison of mechanical properties of the anion exchange membrane one in Example 1 and Comparative Example 1;

[0046] Figure 6 Figure 3 is a graph showing the polarization curve of the fuel cell of the anion exchange membrane two in Example 1;

[0047] Figure 7 Figure 4 is a graph showing the polarization curve of the water electrolysis cell of the anion exchange membrane two in Example 1. DETAILED DESCRIPTION

[0048] The technical solutions of the present application are further illustrated by the following examples.

[0049] Example 1

[0050] S1, dissolve the polymer electrolyte P1 (0.5 g) in 2.5 mL of N,N-dimethylformamide, stir at room temperature until completely dissolved, to obtain a cationic polymer P1 solution.

[0051] S2, add 5.5 mL of methanol to the cationic polymer P1 solution obtained in S1, mix uniformly to obtain a cationic polymer solution with a co-solvent of N,N-dimethylformamide / methanol and a cationic polymer solid content of 7%.

[0052] S3, take the cationic polymer solution of S2 and perform blade coating to coat a cationic polymer layer with an area of 10 cm x 10 cm on a coating film substrate, then lay an expanded polytetrafluoroethylene porous substrate with a thickness of 11 μm on the upper surface thereof, the average pore size being 250 nm and the porosity being 80%, to obtain a single-sided coated anion exchange membrane.

[0053] S4, coat the cationic polymer solution on the upper surface of the single-sided coated anion exchange membrane obtained in S3, dry the solvent, and after peeling off the substrate film, obtain a porous substrate reinforced anion exchange membrane P1-ePTFE with a thickness of 38 μm, wherein the thicknesses of the upper and lower cationic polymer layers are 13.5 μm respectively, and the thickness of the reinforced layer in the middle is 11 μm.

[0054] The above porous substrate reinforced anion exchange membrane P1-ePTFE with counterion Br - is immersed in a 2 mol / L NaCl solution for 24 h and then washed thoroughly with deionized water to obtain a P1-ePTFE anion exchange membrane one with counterion Cl - .

[0055] The above counterion is Br - The porous substrate-enhanced anion exchange membrane P1-ePTFE was immersed in 2 mol / L NaOH solution for 48 h and then thoroughly washed with deionized water to obtain an anti-ion of OH-. - P1-ePTFE anion exchange membrane II.

[0056] The chemical structure of the above-mentioned cationic polymer P1 is as follows:

[0057]

[0058] Application Example 1

[0059] a) Anion exchange membrane fuel cell

[0060] The P1-ePTFE anion exchange membrane II from Example 1 above was modified using Pt / C as both the cathode and anode catalysts, with a Pt loading of 0.5 mg / cm³. -2 A membrane electrode was prepared using catalyst coating membrane technology and applied to H2-O2 fuel cell testing.

[0061] b. Anion exchange membrane water electrolysis cell

[0062] The P1-ePTFE anion exchange membrane II from Example 1 above was modified using Pt / C as both the cathode and anode catalysts, with a Pt loading of 0.5 mg / cm³. -2 Membrane electrodes were prepared using catalyst coating technology and applied to water electrolyzer testing.

[0063] Comparative Example 1

[0064] Preparation of intrinsic P1 anion exchange membrane

[0065] S1. Dissolve the polymer electrolyte P1 (0.8 g) in 6.5 mL of N,N-dimethylformamide and stir at room temperature until completely dissolved. Then pour the solution onto a coating substrate and coat the substrate. Heat at 80 °C for 24 h to fully evaporate the solvent. After peeling off the substrate, an anion exchange membrane P1 with a thickness of 38 μm is obtained.

[0066] The above counterion is Br - The P1 anion exchange membrane was immersed in 2 mol / L NaCl solution for 24 h and then thoroughly washed with deionized water to obtain an anti-counterion of Cl. - The P1 anion exchange membrane.

[0067] The above counterion is Br - The P1 anion exchange membrane was soaked in 2 mol / L NaOH solution for 48 h and then thoroughly washed with deionized water to obtain an anti-counterion of OH-. - The P1 anion exchange membrane II.

[0068] Test Example 1

[0069] The following tests were performed on P1-ePTFE anion exchange membranes I and II obtained in Example 1 and P1 anion exchange membranes I and II obtained in Comparative Example 1 to characterize their basic performance and make comparisons.

[0070] a. Characterization of membrane cross-section morphology

[0071] The P1-ePTFE anion exchange membrane (1cm×3cm) was quenched with liquid nitrogen. The quenched section was then treated with platinum sputtering and gold sputtering using a Hitachi SU3500 sputtering instrument. The cross-sectional image of the sample was obtained using a SEM equipped with an EDS detector at an accelerating voltage of 15.0kV.

[0072] The fracture section of the P1-ePTFE anion exchange membrane was characterized by SEM, and the results are as follows: Figure 1 As shown, the thickness of the upper and lower cation polymer layers in the P1-ePTFE anion exchange membrane is basically consistent, approximately 13 μm. There are no obvious delaminations or gaps between the layers, and the intermediate reinforcement layer is well-filled with no obvious defects. b. Hydroxide ion conductivity

[0073] The four-electrode AC impedance method was used for measurement. P1-ePTFE anion exchange membrane II and P1 anion exchange membrane II were cut into 1cm × 5cm strips, clamped in a fixture, and then placed in a water bath filled with pure water. After installing the electrodes, the electrochemical workstation was connected. In constant current mode (0.1mA), the scanning frequency range was 1MHz-100Hz. The frequency range where impedance was stable was found on the Bode curve, and the resistance R of the anion exchange membrane was then read from the corresponding curve.

[0074] The conductivity of hydroxide ions is calculated using the following formula:

[0075]

[0076] Where R is the resistance of the anion exchange membrane, L is the distance between the electrodes (1.0 cm), w is the width of the anion exchange membrane, and d is the thickness of the anion exchange membrane.

[0077] Based on the hydroxide ion conductivity measured at different temperatures, the hydroxide ion conductivity curves of P1-ePTFE anion exchange membrane II and P1 anion exchange membrane II as a function of temperature are shown in the figure below. Figure 2 As shown, at 80℃, the hydroxide ion conductivity of the P1-ePTFE reinforced membrane II reaches 190 mS·cm. -1The conductivity of hydroxyl ion increased slightly compared with P1 anion exchange membrane two after adding non-functionalized ePTFE matrix.

[0078] c. Water uptake and swelling ratio

[0079] P1-ePTFE anion exchange membrane one and P1 anion exchange membrane one were cut into 1 cm x 8 cm samples, dried in an oven, and the weight of the dried anion exchange membrane was recorded as W dry The anion exchange membrane was then immersed in deionized water, removed every 12 h, wiped off the surface water, and the weight of the anion exchange membrane after immersion at different temperatures (30-80°C) was recorded as W wet .

[0080] The water uptake (WU) was calculated by the following formula,

[0081]

[0082] According to the calculation of the water uptake detected at different temperatures, the water uptake of P1-ePTFE anion exchange membrane one and P1 anion exchange membrane one as a function of temperature was obtained, as shown in Figure 3 .

[0083] The swelling ratio (SR) is an important indicator of the dimensional stability of the membrane, which is calculated by the length of the dry and wet anion exchange membrane (L dry and (L wet ), and is calculated by the following formula:

[0084]

[0085] According to the calculation of the swelling ratio detected at different temperatures, the swelling ratio of P1-ePTFE anion exchange membrane one and P1 anion exchange membrane one as a function of temperature was obtained, as shown in Figure 4 .

[0086] d. Determination of mechanical properties:

[0087] The tensile properties of P1-ePTFE anion exchange membrane one and P1 anion exchange membrane one were determined by electronic universal testing machine at a tensile speed of 10 mm min -1 The P1-ePTFE anion exchange membrane one and P1 anion exchange membrane one were cut into dumbbell shapes, and each group of samples was set with 3 parallel samples. The samples were equilibrated in the test environment for 24 hours before use. The test results are as follows Figure 5As shown, the tensile strength of P1-ePTFE anion exchange membrane reaches 55 MPa and the elongation at break exceeds 110%, while the tensile strength of P1 anion exchange membrane is only 35 MPa and the elongation at break is less than 80%. This proves that the P1-ePTFE anion exchange membrane reinforced with ePTFE has superior mechanical properties.

[0088] e. Measurement of fuel cell performance

[0089] The P1-ePTFE anion exchange membrane was used with Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 Membrane electrodes were prepared using catalyst coating technology. The gas flow rate was 300 mL / min. -1 Under conditions of 150 kPa back pressure and 100% relative humidity, the electrochemical performance of the P1-ePTFE anion exchange membrane II in Example 1 was tested. Figure 6 As shown, it reaches 1.2 W·cm -2 Maximum power density.

[0090] f. Determination of the performance of the water electrolysis cell

[0091] The P1-ePTFE anion exchange membrane was used with Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 Membrane electrodes were prepared using catalyst-coated membrane technology. The performance of the water electrolyzer was tested at 80°C in 1M KOH solution, and the performance of the water electrolyzer using the P1-ePTFE anion exchange membrane II in Example 1 was evaluated. Figure 7 As shown.

[0092] In summary, at 80℃, the hydroxide ion conductivity of the P1-ePTFE anion exchange membrane reaches 190 mS·cm. -1 It possesses high water absorption, an in-plane swelling rate of less than 10%, and excellent mechanical properties, making it suitable for use in fuel cells. In an alkaline membrane water electrolyzer, it can achieve a flux of 5.75 Acm at 2V. -2 High current density.

[0093] Example 2

[0094] S1. Dissolve polymer electrolyte P2 (0.7g) in 2.0mL of N,N-dimethylformamide and stir at room temperature until completely dissolved to obtain a cationic polymer P1 solution.

[0095] S2, 7.5 mL of isopropanol was added into the cationic polymer P1 solution obtained in S1, and mixed to obtain a cationic polymer solution with co-solvent of N,N-dimethylformamide / isopropanol and cationic polymer solid content of 8%.

[0096] S3, the cationic polymer solution obtained in S2 was subjected to blade coating to coat a cationic polymer layer with an area of 10 cm x 10 cm on a film substrate, and then a polyethylene porous substrate with a thickness of 8 μm, an average pore size of 110 nm and a porosity of 45% was laid on the upper surface of the cationic polymer layer to obtain a single-side coated anion exchange membrane.

[0097] S4, the cationic polymer solution was coated on the upper surface of the single-side coated anion exchange membrane obtained in S3, and the solvent was dried, and after the substrate film was peeled off, a porous substrate reinforced anion exchange membrane P2-PE with a thickness of 40 μm was obtained, wherein the thicknesses of the upper and lower cationic polymer layers were 16 μm respectively, and the thickness of the reinforced layer in the middle was 8 μm.

[0098] The above-mentioned porous substrate reinforced anion exchange membrane P2-PE with counterion Br - was immersed in a 2 mol / L NaOH solution for 24 h and then washed with deionized water to obtain a P2-PE anion exchange membrane with counterion OH - .

[0099] The chemical structure of the above-mentioned cationic polymer P2 is as follows:

[0100]

[0101] Application Example 2

[0102] a. Anion exchange membrane fuel cell

[0103] The above-mentioned P2-PE anion exchange membrane with counterion OH - in Example 2 was used to prepare a membrane electrode by catalyst coated membrane technology, with Pt / C as the cathode and anode catalysts, wherein the loading amount of Pt was 0.5 mg cm -2 , and the membrane electrode was applied in H2-O2 fuel cell test.

[0104] b. Anion exchange membrane water electrolyzer

[0105] The above-mentioned P2-PE anion exchange membrane with counterion OH - in Example 2 was used to prepare a membrane electrode by catalyst coated membrane technology, with Pt / C as the cathode and anode catalysts, wherein the loading amount of Pt was 0.5 mg cm -2 , and the membrane electrode was applied in water electrolyzer test.

[0106] Example 3

[0107] S1, dissolve the polymer electrolyte P3 (0.5 g) in 2.0 mL of N,N-dimethylformamide, stir at room temperature until completely dissolved, to obtain a cationic polymer P3 solution.

[0108] S2, add 5.0 mL of isopropyl alcohol to the cationic polymer P1 solution obtained in S1, mix well to obtain a cationic polymer solution with a co-solvent of N,N-dimethylformamide / isopropyl alcohol and a cationic polymer solid content of 10%.

[0109] S3, take the cationic polymer solution of S2 and perform blade coating to coat a cationic polymer layer with an area of 10 cm x 20 cm on a coating film substrate, then lay a polyethylene porous substrate with a thickness of 8 μm on the upper surface, with an average pore size of 110 nm and a porosity of 45%, to obtain a single-sided coated anion exchange membrane.

[0110] S4, coat the cationic polymer solution on the upper surface of the single-sided coated anion exchange membrane obtained in S3, dry the solvent, and after peeling off the base film, obtain a porous substrate reinforced anion exchange membrane P3-PE with a thickness of 20 μm, wherein the thicknesses of the upper and lower cationic polymer layers are 6 μm respectively, and the thickness of the middle reinforcing layer is 8 μm.

[0111] The above-mentioned counterion for Br - The porous substrate reinforced anion exchange membrane P3-PE is immersed in a 2 mol / L NaOH solution for 24 h and then washed thoroughly with deionized water to obtain a P3-PE anion exchange membrane with OH - as the counterion.

[0112] The chemical structure of the above-mentioned cationic polymer P3 is as follows:

[0113]

[0114] Application Example 3

[0115] a, anion exchange membrane fuel cell

[0116] The P3-PE anion exchange membrane with OH - as the counterion in the above-mentioned Example 3 is used to prepare a membrane electrode by catalyst coating film technology, using Pt / C as the cathode and anode catalysts, with a Pt loading of 0.5 mg cm -2 , and applied in H2-O2 fuel cell testing.

[0117] b, anion exchange membrane water electrolyzer

[0118] The P3-PE anion exchange membrane with OH -P3-PE anion exchange membrane, Pt / C as cathode and anode catalysts, and the loading of Pt is 0.5 mg cm -2 The membrane electrode was prepared by catalyst-coated membrane technology and applied in water electrolysis cell test.

[0119] Example 4

[0120] S1, dissolve the polymer electrolyte P4 (0.55 g) in 3.0 mL of dimethyl sulfoxide, stir at room temperature until completely dissolved, and obtain a cationic polymer P4 solution.

[0121] S2, add 1.2 mL of n-butanol to the cationic polymer P4 solution obtained in S1, mix uniformly to obtain a cationic polymer solution with dimethyl sulfoxide / n-butanol as co-solvent and a cationic polymer solid content of 12%.

[0122] S3, take the cationic polymer solution in S2 and perform blade coating to obtain a cationic polymer layer with an area of 8 cm x 10 cm on the coating film substrate, and then lay an expanded polyvinylidene fluoride porous substrate with a thickness of 8 μm on the upper surface, the average pore size is 300 nm, and the porosity is 78%, to obtain a single-sided coated anion exchange membrane.

[0123] S4, coat the cationic polymer solution on the upper surface of the single-sided coated anion exchange membrane obtained in S3, dry the solvent, and after peeling off the base film, obtain a porous substrate reinforced anion exchange membrane P4-ePVDF with a thickness of 38 μm, wherein the thicknesses of the upper and lower cationic polymer layers are 15 μm respectively, and the thickness of the reinforced layer in the middle is 8 μm.

[0124] The above-mentioned counterion is Br - The porous substrate reinforced anion exchange membrane P4-ePVDF with Br - as the counterion is immersed in a 2 mol / L NaOH solution for 24 h and then washed with deionized water to obtain a P4-ePVDF anion exchange membrane with OH - as the counterion.

[0125] The chemical structure of the above-mentioned cationic polymer P4 is as follows:

[0126]

[0127] Application Example 4

[0128] a, anion exchange membrane fuel cell

[0129] The above-mentioned P4-ePVDF anion exchange membrane with OH - as the counterion in Example 4, Pt / C as cathode and anode catalysts, and the loading of Pt is 0.5 mg cm -2, the membrane electrode was prepared by catalyst coated membrane technology and applied in H2-O2 fuel cell test.

[0130] b、anion exchange membrane water electrolyzer

[0131] The P4-ePVDF anion exchange membrane with OH - as counter ion in the above example 4 was used, Pt / C was used as cathode and anode catalyst, the loading of Pt was 0.5 mg cm -2 -2, the membrane electrode was prepared by catalyst coated membrane technology and applied in water electrolyzer test.

[0132] Example 5

[0133] S1, the polymer electrolyte P5 (1.2 g) was dissolved in 5.0 mL N, N- dimethylformamide, stirred at room temperature until completely dissolved, and the cationic polymer P5 solution was obtained.

[0134] S2, 2.5 mL of isopropyl alcohol was added to the cationic polymer P5 solution obtained in S1, and the cationic polymer solution with N, N-dimethylformamide / isopropyl alcohol as co-solvent and 15% solid content of cationic polymer was obtained.

[0135] S3, the cationic polymer solution in S2 was taken for blade coating, and a cationic polymer layer with an area of 16 cm x 9 cm was coated on the film coating substrate, and then an expanded polytetrafluoroethylene porous substrate with a thickness of 10 μm was laid on the upper surface, with an average pore size of 250 nm and a porosity of 80%, to obtain a single-sided coated anion exchange membrane.

[0136] S4, the cationic polymer solution was coated on the upper surface of the single-sided coated anion exchange membrane obtained in S3, and the solvent was dried, and after the base film was peeled off, a porous substrate reinforced anion exchange membrane P5-ePTFE was obtained, with a thickness of 70 μm, and the thicknesses of the upper and lower cationic polymer layers were 30 μm respectively, and the thickness of the reinforced layer in the middle was 10 μm.

[0137] The porous substrate reinforced anion exchange membrane P5-ePTFE with Br - as counter ion was immersed in 2 mol / L NaOH solution for 24 h and then washed with deionized water to obtain a P5-ePTFE anion exchange membrane with OH - as counter ion.

[0138] The chemical structure of the above cationic polymer P5 is as follows:

[0139]

[0140] Application example 5

[0141] a、anion exchange membrane fuel cell

[0142] The P5-ePTFE anion exchange membrane with OH - as counter ion in Example 5 above was used in H2-O2 fuel cell test with Pt / C as cathode and anode catalyst, where the loading of Pt was 0.5 mg cm -2

[0143] b. Water electrolyzer with anion exchange membrane

[0144] The P5-ePTFE anion exchange membrane with OH - as counter ion in Example 5 above was used in water electrolyzer test with Pt / C as cathode and anode catalyst, where the loading of Pt was 0.5 mg cm -2

[0145] Example 6

[0146] S1, Dissolve the polymer electrolyte P6 (0.6 g) in 4.0 mL of N,N-dimethylformamide, stir at room temperature until completely dissolved, to obtain a cationic polymer P6 solution.

[0147] S2, Add 2.0 mL of ethanol to the cationic polymer P6 solution obtained in S1, mix well to obtain a cationic polymer solution with N,N-dimethylformamide / ethanol as co-solvent and a cationic polymer solid content of 10%.

[0148] S3, Take the cationic polymer solution in S2 and perform blade coating to coat a cationic polymer layer with an area of 20 cm x 10 cm on a film coating substrate, then lay a polyethylene porous substrate with a thickness of 7 μm on the upper surface, with an average pore size of 80 nm and a porosity of 45%, to obtain a single-sided coated anion exchange membrane.

[0149] S4, Coat the upper surface of the single-sided coated anion exchange membrane obtained in S3 with a cationic polymer solution, dry the solvent, and after peeling off the base film, obtain a porous substrate reinforced anion exchange membrane P6-PE with a thickness of 27 μm, where the thicknesses of the upper and lower cationic polymer layers are 10 μm respectively, and the thickness of the reinforced layer in the middle is 7 μm.

[0150] The porous substrate reinforced anion exchange membrane P6-PE with Br - as counter ion above was immersed in a 2 mol / L NaOH solution for 24 h and then washed thoroughly with deionized water to obtain a P6-PE anion exchange membrane with OH - as counter ion.

[0151] The chemical structure of the cationic polymer P6 above is as follows:​​

[0152]

[0153] Example 6

[0154] a. Anion exchange membrane fuel cell

[0155] The P6-PE anion exchange membrane with OH - counter anion in Example 6 above was used to prepare membrane electrode by catalyst coated membrane technique with Pt / C as cathode and anode catalyst, where the loading of Pt was 0.5 mg cm -2

[0156] b. Anion exchange membrane water electrolyzer

[0157] The P6-PE anion exchange membrane with OH - counter anion in Example 6 above was used to prepare membrane electrode by catalyst coated membrane technique with Pt / C as cathode and anode catalyst, where the loading of Pt was 0.5 mg cm -2

[0158] Example 7

[0159] S1. Dissolve the polymer electrolyte P7 (0.5 g) in 3.2 mL of dimethyl sulfoxide at room temperature with stirring until complete dissolution to obtain a cationic polymer P7 solution.

[0160] S2. Add 1.5 mL of ethanol to the cationic polymer P7 solution obtained in S1 and mix well to obtain a cationic polymer solution with a co-solvent of dimethyl sulfoxide / ethanol and a cationic polymer solid content of 10.5%.

[0161] S3. Take the cationic polymer solution in S2 and perform blade coating to obtain a cationic polymer layer with an area of 8 cm x 10 cm on a film coating substrate, and then lay an expanded polytetrafluoroethylene porous substrate with a thickness of 10 pm on the upper surface of the cationic polymer layer, where the average pore size is 250 nm and the porosity is 80%, to obtain a single-sided coated anion exchange membrane.

[0162] S4. Coat the cationic polymer solution on the upper surface of the single-sided coated anion exchange membrane obtained in S3, dry the solvent, and then peel off the substrate film to obtain a porous substrate reinforced anion exchange membrane P7-ePTFE with a thickness of 50 pm, where the thicknesses of the upper and lower cationic polymer layers are 20 pm and the thickness of the reinforced layer in the middle is 10 pm.

[0163] The P6-PE anion exchange membrane with Br - ​​The porous substrate-reinforced anion exchange membrane P7-ePTFE was immersed in 2 mol / L NaOH solution for 24 h and then thoroughly washed with deionized water to obtain an anti-ion of OH-. - P7-ePTFE anion exchange membrane.

[0164] The chemical structure of the above-mentioned cationic polymer P7 is as follows:

[0165]

[0166] Application Example 7

[0167] a) Anion exchange membrane fuel cell

[0168] In Example 7 above, the counter ion is OH. - The P7-ePTFE anion exchange membrane uses Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 A membrane electrode was prepared using catalyst coating membrane technology and applied in H2-O2 fuel cell testing.

[0169] b. Anion exchange membrane water electrolysis cell

[0170] In Example 7 above, the counter ion is OH. - The P7-ePTFE anion exchange membrane uses Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 Membrane electrodes were prepared using catalyst coating technology and applied in water electrolyzer testing.

[0171] Example 8

[0172] S1. Dissolve polymer electrolyte P8 (1.0 g) in 2.8 mL of N,N-dimethylformamide and stir at room temperature until completely dissolved to obtain a cationic polymer P8 solution.

[0173] S2. Add 6.0 mL of isopropanol to the cationic polymer P8 solution obtained in S1, and mix well to obtain a cationic polymer solution with N,N-dimethylformamide / isopropanol as the cosolvent and a cationic polymer solid content of 11.5%.

[0174] S3. Take the S2 cationic polymer solution and apply it by scraping. Apply a cationic polymer layer with an area of ​​10cm×10cm on the coating substrate. Then, lay an expanded polytetrafluoroethylene porous substrate with a thickness of 20μm on its upper surface. The average pore size is 200nm and the porosity is 78%, thus obtaining a single-sided coated anion exchange membrane.

[0175] S4, coating the cationic polymer solution on the upper surface of the single-sided coated anion exchange membrane obtained in S3, drying the solvent, and peeling off the base film to obtain a porous substrate reinforced anion exchange membrane P8-ePTFE having a thickness of 80 μm, wherein the thicknesses of the upper and lower cationic polymer layers are 30 μm respectively, and the thickness of the middle reinforced layer is 20 μm.

[0176] The above counterion is Br - The P8-ePTFE anion exchange membrane with OH - as the counterion is obtained by immersing the above porous substrate reinforced anion exchange membrane P8-ePTFE with Br - as the counterion in a 2 mol / L NaOH solution for 24 h and then washing it thoroughly with deionized water.

[0177] The chemical structure of the above cationic polymer P8 is as follows:

[0178]

[0179] Application Example 8

[0180] a, anion exchange membrane fuel cell

[0181] The P8-ePTFE anion exchange membrane with OH - as the counterion obtained in the above Example 8 is used to prepare a membrane electrode by the catalyst-coated membrane technology, with Pt / C as the cathode and anode catalysts, wherein the loading of Pt is 0.5 mg cm -2 , and the membrane electrode is applied in H2-O2 fuel cell tests.

[0182] b, anion exchange membrane water electrolyzer

[0183] The P8-ePTFE anion exchange membrane with OH - as the counterion obtained in the above Example 8 is used to prepare a membrane electrode by the catalyst-coated membrane technology, with Pt / C as the cathode and anode catalysts, wherein the loading of Pt is 0.5 mg cm -2 , and the membrane electrode is applied in water electrolyzer tests.

[0184] Example 9

[0185] S1, dissolving the polymer electrolyte P9 (0.8 g) in 3.0 mL of N,N-dimethylformamide, stirring at room temperature until complete dissolution, to obtain a cationic polymer P9 solution.

[0186] S2, adding 2.0 mL of ethanol to the cationic polymer P8 solution obtained in S1, and mixing uniformly to obtain a cationic polymer solution with N,N-dimethylformamide / ethanol as the co-solvent and a cationic polymer solid content of 15%.

[0187] S3. Take the S2 cationic polymer solution and apply it by scraping. Apply a cationic polymer layer with an area of ​​15cm×20cm on the coating substrate. Then, lay a polyethylene porous substrate with a thickness of 7μm on its upper surface. The average pore size is 80nm and the porosity is 45%, thus obtaining a single-sided coated anion exchange membrane.

[0188] S4. A cationic polymer solution is coated on the surface of the single-sided coated anion exchange membrane obtained in S3. The solvent is dried, and the base membrane is peeled off to obtain a porous substrate-reinforced anion exchange membrane P9-PE with a thickness of 25 μm. The thickness of the upper and lower cationic polymer layers is 9 μm and the thickness of the middle reinforcement layer is 7 μm.

[0189] The above counterion is Br - The porous substrate-reinforced anion exchange membrane P9-PE was soaked in 2 mol / L NaOH solution for 24 h and then thoroughly washed with deionized water to obtain an anti-counterion of OH-. - P9-PE anion exchange membrane.

[0190] The chemical structure of the above-mentioned cationic polymer P9 is as follows:

[0191]

[0192] Application Example 9

[0193] a) Anion exchange membrane fuel cell

[0194] In Example 9 above, the counterion is OH. - The P9-PE anion exchange membrane uses Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 A membrane electrode was prepared using catalyst coating membrane technology and applied in H2-O2 fuel cell testing.

[0195] b. Anion exchange membrane water electrolysis cell

[0196] In Example 9 above, the counterion is OH. - The P9-PE anion exchange membrane uses Pt / C as both the cathode and anode catalysts, with Pt loading at 0.5 mg / cm³. -2 A membrane electrode was prepared using catalyst coating technology and applied to water electrolyzer testing.

[0197] Example 10

[0198] S1. Dissolve polymer electrolyte P10 (0.9g) in 3.5mL of dimethyl sulfoxide and stir at room temperature until completely dissolved to obtain a cationic polymer P10 solution.

[0199] S2, 5.0 mL of n-propanol was added into the cationic polymer P8 solution obtained in S1, and mixed to obtain a cationic polymer solution with dimethyl sulfoxide / n-propanol as the co-solvent and the solid content of the cationic polymer being 11%.

[0200] S3, the cationic polymer solution obtained in S2 was subjected to blade coating to form a cationic polymer layer with an area of 10 cm x 10 cm on a film substrate, and then a polyethylene porous substrate with a thickness of 15 μm, an average pore size of 80 nm and a porosity of 43% was laid on the upper surface of the cationic polymer layer to obtain a single-side coated anion exchange membrane.

[0201] S4, the cationic polymer solution was coated on the upper surface of the single-side coated anion exchange membrane obtained in S3, and the solvent was dried, and then the substrate was peeled off to obtain a porous substrate reinforced anion exchange membrane P10-PE with a thickness of 85 μm, wherein the thicknesses of the upper and lower cationic polymer layers were 35 μm respectively, and the thickness of the reinforced layer in the middle was 15 μm.

[0202] The above-mentioned porous substrate reinforced anion exchange membrane P10-PE with Br - as the counter ion was immersed in a 2 mol / L NaOH solution for 24 h and then washed with deionized water to obtain a P10-PE anion exchange membrane with OH - as the counter ion.

[0203] The chemical structure of the above-mentioned cationic polymer P10 is as follows:

[0204]

[0205] Application Example 10

[0206] a, fuel cell

[0207] The above-mentioned P10-PE anion exchange membrane with OH - as the counter ion in Example 10 was used to prepare a membrane electrode by a catalyst coated membrane technique with Pt / C as the cathode and anode catalysts, wherein the loading amount of Pt was 0.5 mg cm -2 , and the membrane electrode was applied in H2-O2 fuel cell test.

[0208] b, water electrolyzer

[0209] The above-mentioned P10-PE anion exchange membrane with OH - as the counter ion in Example 10 was used to prepare a membrane electrode by a catalyst coated membrane technique with Pt / C as the cathode and anode catalysts, wherein the loading amount of Pt was 0.5 mg cm -2 , and the membrane electrode was applied in water electrolyzer test.

[0210] Therefore, the application provides a porous substrate reinforced anion exchange membrane and a preparation method and application thereof. A certain amount of alcohol solvent is directly added to a cationic polymer solution to greatly improve the compatibility of the cationic polymer solution with the porous substrate, so that the cationic polymer is efficiently infiltrated in the porous substrate. The method effectively simplifies the membrane preparation process in actual production and is suitable for large-scale production. In addition, the addition of alcohol low-boiling solvent reduces the use of high-boiling solvents such as N,N-dimethylformamide and dimethyl sulfoxide in the initial coating solution, facilitating subsequent solvent recovery and drying processes, and effectively reducing production costs. The porous substrate reinforced anion exchange membrane with the above structure as the filling polymer electrolyte has good electrochemical performance, dimensional stability and excellent mechanical properties, and has a good application prospect in alkaline membrane energy conversion devices. The preparation method of the porous substrate reinforced anion exchange membrane has simple and continuous production process and low production cost, and is suitable for large-scale continuous production.

[0211] In the description of the present specification, the description referring to the terms "one experimental example", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the experimental example or example are included in at least one experimental example or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0212] Finally, it should be noted that: the above experimental examples are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements also cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A porous substrate reinforced anion exchange membrane, characterized by, The anion exchange membrane has a sandwich type structure, which comprises a porous substrate arranged in the middle and cationic polymers arranged on the top and bottom, and the internal voids of the porous substrate are filled with the cationic polymers; The molecular structure of the cationic polymer is as follows: n represents the degree of polymerization, and n is an integer between 10-1,000,000; The Ar fragments are independently selected from the disubstituted fragments Ar1 and the polysubstituted fragments Ar2, and the molar ratio of the Ar2 fragments to the Ar1 fragments is r, and 0≤r≤1.0; Ar1 is independently selected from one or more of the following structures: Ar2 is independently selected from one or more of the following structures: R 1 a hydrogen atom, a hydrocarbon group having carbon atoms number comprised between 1 and 20 or a completely or partially fluorinated alkyl group having carbon atoms number comprised between 1 and 6; k=0 or 1; x=0-12; Z is independently selected from one or more of H atoms, quaternary ammonium cations and nitrogen-containing heterocyclic cations.

2. The porous substrate reinforced anion exchange membrane according to claim 1, wherein The quaternary ammonium cation has the following formula: wherein R 2 -R 7 The carbon atom-containing hydrocarbon groups are independently selected to have a number of carbon atoms between 1 and 20, and R 2 and R 6 may be connected to each other either intermolecularly or intramolecularly; J = 0-3; the counter ion A - is selected from one or more of a halide ion, a methyl sulfate ion, a hydroxide ion, or a bicarbonate ion.

3. The porous substrate reinforced anion exchange membrane according to claim 1, wherein The nitrogen-containing heterocyclic cation comprises one or more of partially or completely substituted pyrazoles, pyrroles, piperidines, imidazoles and quinine cations, and has the following structure: wherein R 81 - R 810 are independently selected from a hydrocarbon group having a carbon number of 1 to 20, a counter ion A - is selected from one or more of a halide ion, a methyl sulfate ion, a hydroxide ion, or a bicarbonate ion.

4. A method for producing a porous substrate-reinforced anion exchange membrane according to any one of claims 1 to 3, characterized by, The method comprises the following steps: S1, dissolving the cationic polymer in a first organic solvent to obtain a first cationic polymer solution; S2, adding a second organic solvent to the first cationic polymer solution obtained in S1, and uniformly mixing to obtain a second cationic polymer solution containing a co-solvent; S3, coating the second cationic polymer solution containing the co-solvent obtained in S2 on a substrate to perform coating; S4, laying a porous substrate on the surface of the coated substrate obtained in S3, and drying to obtain a single-sided coated anion exchange membrane; S5, coating a second cationic polymer solution on the surface of the single-sided coated anion exchange membrane obtained in S4, removing the solvent in a drying process, and peeling off after drying to obtain a porous substrate reinforced anion exchange membrane.

5. The method of claim 4, wherein the porous substrate is a porous ceramic substrate. The first organic solvent used in S1 is a polar aprotic solvent, including at least one of dimethyl sulfoxide, N-methyl pyrrolidone, N,N-dimethylacetamide or N,N-dimethylformamide; and the second organic solvent used in S2 is at least one of C1-C10 alcohol solvents.

6. The method of claim 4, wherein the porous substrate is a porous ceramic substrate. The second organic solvent is added in an amount of 10-150wt% of the first cationic polymer solution; and the solid content of the first cationic polymer solution is 10-40wt%.

7. The method of claim 4, wherein the porous substrate is a porous ceramic substrate. The coating method used in S3 and S5 includes at least one of slot coating, doctor blade, wire bar and micro-recess coating, and the coating thickness is 8-500μm.

8. The method of claim 4, wherein the porous substrate is a porous ceramic substrate. The porous substrate used in S4 is at least one of polyethylene, polypropylene, expanded polytetrafluoroethylene, expanded polyvinylidene fluoride, polyphenylene sulfide, polyether ether ketone or nylon, and the thickness range is 3-100μm.

9. Application of the porous substrate reinforced anion exchange membrane according to any one of claims 1-3 in an alkaline membrane energy conversion device.

Images