Propargyl-grafted poly (aryl piperidinium) copolymer ionic polymer, cross-linked anion exchange membrane and preparation method of cross-linked anion exchange membrane

Abstract

The present invention relates to: a poly (aryl piperidinium) copolymer ionic polymer which is grafted with propargyl, contains a piperidinium group, and does not contain any aryl ether bond in the polymer main chain; an anion exchange membrane formed by cross-linking thereof; and a preparation method thereof. The propargyl-grafted poly (aryl piperidinium) copolymer ionic polymer has excellent chemical stability, thermal stability, ionic conductivity, mechanical properties, dimensional stability and durability. In addition, according to the cross-linked anion exchange membrane prepared from the cross-linked anion exchange membrane, the peel strength of a catalyst layer is greatly improved, so that the interaction between the ionic polymer and the membrane is promoted, the catalyst layer is stabilized, and the durability of a fuel cell is remarkably improved.

Description

Technical Field

[0001] The present disclosure relates to a poly(arylpiperidinium) copolymer ionomer grafted with a propargyl group, a cross-linked anion exchange membrane and a preparation method. More specifically, the present disclosure relates to a technology for synthesizing a poly(arylpiperidinium) copolymer ionomer, wherein the ionomer is grafted with a propargyl group and a piperidinium is introduced therein, and there is no aryl ether bond in the polymer main chain; and a cross-linked anion exchange membrane is prepared therefrom, which is applied to alkaline fuel cells, water electrolysis devices, etc. Background Art

[0002] Anion-exchange membrane fuel cells (AEMFCs) and anion-exchange membrane water electrolyzers (AEMWEs) are promising energy conversion devices that can replace expensive proton exchange membrane fuel cells (PEMFCs). Anion-exchange membrane fuel cells or water electrolysis technologies have made significant progress in the past few years due to the development of non-platinum catalyst-based anion exchange membranes and ionic polymers with high activity, durability, and conductivity.

[0003] Advanced anion exchange membranes achieve an anion conductivity of 150 mS cm at 80 °C -1 or higher, and exhibits remarkable chemical stability (degradation <10%) in harsh alkaline environments (80°C, 1M NaOH or KOH solution, over 1000 hours). -2 1 or higher, similar to those of commercial PEMFCs. However, most AEMFCs still have durability issues during long-term operation. -2 AEMFC that can operate stably at 80°C for more than 500 hours at a current density of 1.1 or lower.

[0004] The reason for the poor durability of AEMFC is the unstable contact between the catalyst layer and the membrane. The interfacial stability of the electrochemical reaction occurring between the catalyst layer and the membrane is one of the factors determining the performance and lifespan of AEMFC and AEMWE. In particular, under high current density conditions, the rapid adsorption and desorption of water in the catalyst layer reduce the interfacial stability between the catalyst layer and the membrane, leading to the aggregation and desorption of catalyst particles from the catalyst layer. In addition, the excessive swelling of the ionomer interferes with the movement of hydrogen gas as fuel. An ideal catalyst layer should be porous and have a stable three-phase interface structure, where the catalyst is evenly distributed, and the membrane and the ionomer should have a durable chemical structure. This is to reduce the interfacial resistance between the catalyst layer and the anion exchange membrane and enable the ionomer to have good adhesion ability, thereby improving the stability of the catalyst layer. Therefore, developing technologies for stabilizing the catalyst layer is very important for achieving durable AEMFC and AEMWE.

[0005] Meanwhile, a crosslinked poly(arylpiperidinium) anion exchange membrane grafted with propargyl groups and introducing piperidinium groups on the polymer backbone without any aryl ether bonds has not been synthesized, and the technology for applying it to alkaline fuel cells or water electrolysis is not clear.

[0006] Therefore, the inventors of the present disclosure have conducted continuous research to expand the application fields of aromatic polymer ion exchange membranes with excellent thermal stability, chemical stability, and mechanical properties. We have attempted to stabilize the catalyst layer by promoting the interfacial interaction between the catalyst layer and the AEM and the catalyst layer itself, thereby significantly improving the durability of AEMFC, which is the weakness of traditional AEMFC.

[0007] That is to say, the present disclosure is completed by synthesizing a poly(arylpiperidinium) copolymer ionomer (wherein propargyl groups are grafted and piperidinium groups are introduced, but there are no aryl ether bonds in the polymer backbone), and by preparing an anion exchange membrane with a crosslinked structure therefrom. It has been found that the anion exchange membrane can be applied to alkaline fuel cells, water electrolysis devices, supercapacitors, carbon dioxide reduction, redox flow batteries, etc.

[0008]

Related Technical References

[0009]

Patent Documents

[0010] Patent Document 1: Korean Patent Publication No. 10-2021-0071810.

[0011] Patent Document 2: International Patent Publication No. WO 2019 / 068051.

[0012] Patent document 3: Chinese Patent Publication No. CN 109384908.

[0013] Patent Document 4: U.S. Patent Publication No. US2019 / 0036143. Summary of the invention

[0014]

Technical issues

[0015] The present disclosure aims to provide a propargyl-grafted poly(arylpiperidinium) copolymer ionomer having high chemical stability, thermal stability, ionic conductivity, mechanical properties, dimensional stability and durability; and a method for preparing the ionomer.

[0016] The present disclosure also aims to provide an anion exchange membrane with a cross-linked structure, wherein the membrane is prepared from a novel propargyl-grafted poly(arylpiperidinium) copolymer ion polymer. Since the interaction between the catalyst layer and the anion exchange membrane is promoted, the dimensional stability of the membrane is greatly improved and the membrane has a stable catalyst layer. Therefore, the membrane is suitable for alkaline fuel cells, water electrolysis devices, supercapacitors, carbon dioxide reduction, redox flow batteries, etc., and the durability is significantly improved.

[0017]

Technical solution

[0018] The present disclosure provides a propargyl-grafted poly(arylpiperidinium) copolymer ionomer having a repeating unit represented by <Chemical Formula 1>.

[0019] <Chemical Formula 1>

[0020]

[0021] In Chemical Formula 1, the aryl group is two or more different compounds selected from compounds represented by the following structural formulas:

[0022]

[0023] In addition, the present disclosure also provides a method for preparing a poly(arylpiperidinium) copolymer ion polymer grafted with a propargyl group, comprising: (I) a step of dissolving (a) two or more different compounds represented by the following structural formula as monomers, and (b) 1-methyl-4-piperidone in an organic solvent to form a solution; (II) a step of slowly adding a strong acid catalyst to the solution, and stirring and reacting the reaction mixture to obtain a viscous solution; (III) a step of precipitating, washing and drying the viscous solution to obtain a solid polymer; (IV) a step of adding potassium carbonate, propargyl bromide and an excess of methyl halide to a polymer solution formed by dissolving the solid polymer in an organic solvent, and reacting to form a quaternary piperidine salt grafted with a propargyl group; and (V) a step of precipitating, washing and drying the mixed solution.

[0024]

[0025] In addition, the present disclosure provides an anion exchange membrane formed by cross-linking the poly(arylpiperidinium) copolymer grafted with propargyl groups.

[0026] In addition, the present disclosure provides a method for preparing a cross-linked anion exchange membrane, comprising: (i) dissolving the poly(arylpiperidinium) copolymer grafted with propargyl groups in an organic solvent to form a polymer solution; (ii) casting the polymer solution on a glass plate and heating to remove the organic solvent to obtain a dry membrane; (iii) heat-treating the dry membrane to obtain a membrane inducing a cross-linking reaction; and (iv) treating the dry membrane with 1 M NaHCO 3 Or the step of treating the obtained membrane with 1 M NaOH, washing it several times with ultrapure water, and drying it.

[0027] In addition, the present disclosure provides an alkaline fuel cell comprising the cross-linked anion exchange membrane.

[0028] In addition, the present disclosure provides a water electrolysis device, comprising the cross-linked anion exchange membrane.

[0029] In addition, the present disclosure provides a supercapacitor comprising the cross-linked anion exchange membrane.

[0030] In addition, the present disclosure provides a carbon dioxide reduction device, comprising the cross-linked anion exchange membrane.

[0031] In addition, the present disclosure provides a redox flow battery comprising the cross-linked anion exchange membrane.

[0032]

Beneficial Effects

[0033] The propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to the present disclosure has excellent chemical and thermal stability, ionic conductivity, mechanical properties, dimensional stability, and durability.

[0034] In addition, the peel strength of the catalyst layer of the cross-linked anion exchange membrane prepared from the novel propargyl-grafted poly(arylpiperidinium) copolymer ionomer is significantly improved, thereby promoting the interaction between the ionomer and the membrane, stabilizing the catalyst layer, and significantly improving the durability of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The poly(arylpiperidinium) copolymer ionomers Trip-PFBP-Pr-m series and PDTP-Pr-m series (m is 10, 30 or 50) grafted with propargyl groups obtained in Synthesis Examples 1 to 6 of the present disclosure are shown. 1 H NMR spectroscopy.

[0036] Figure 2 The (A) moisture content and (B) expansion rate of the cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30 or 50) in Preparation Examples 1 to 6 of the present disclosure after heat treatment at 170°C for 0 minutes, 120 minutes and 240 minutes.

[0037] Figure 3 The analysis results of the change of the cross-linking degree of the anion exchange membrane x-PDTP-Pr-50 prepared in Preparation Example 3 of the present disclosure as a function of heat treatment time are shown [A: FT-IR spectrum of the x-PDTP-Pr-50 anion exchange membrane as a function of heat treatment time; B: residual propargyl groups in the x-PDTP-Pr-50 anion exchange membrane as a function of heat treatment time (calculated by integrating the peak of the propargyl groups in the FT-IR spectrum)].

[0038] Figure 4 The contact angles of the cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30, 50) prepared in Preparation Examples 1 to 6 of the present disclosure and the PDTP and Trip-PFBP prepared in Comparative Examples 1 and 2 measured after heat treatment at 170°C for 120 minutes are shown.

[0039] Figure 5The thermogravimetric analysis (TGA) results of the Trip-PFBP-Pr-m series and PDTP-Pr-m series (before heat treatment) prepared in Synthesis Examples 1 to 6 of the present disclosure, and the cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series prepared in Preparation Examples 1 to 6 after heat treatment at 170°C for 120 minutes (m is 10, 30 or 50).

[0040] Figure 6 The cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30 or 50) prepared in Preparation Examples 1 to 6 of the present disclosure are shown in Figure 2 after heat treatment at 170°C for 0 minutes, 120 minutes and 240 minutes, respectively. 3 2- Conductivity (30℃).

[0041] Figure 7 The peel strength of the catalyst coated membranes as well as the anion exchange membranes depending on the copolymer ionomer type is shown.

[0042] FIG8 shows the electrochemical stability data of the catalyst layer analyzed by the rotating disk electrode (RDE) test [transmission electron microscopy images, average nanoparticle size, linear scan voltammograms (LSV) of the oxygen reduction reaction (ORR) of the catalysts with different ionic polymers (A: Trip-PFBP, B: x-Trip-PFBP-10, C: x-Trip-PFBP-30, D: x-Trip-PFBP-50)].

[0043] Fig. 9 The performance of the fuel cell is shown to be dependent on the degree of crosslinking of the copolymer ionomer and the anion exchange membrane.

[0044] Fig.10 Results are shown for measuring the in situ durability of a fuel cell based on the anion exchange membrane x-PDTP-Pr-10 using an asymmetric copolymer ionomer.

[0045] Fig.11 The water electrolysis performance (linear sweep voltammogram, LSV) and the resistance (potentiostatic electrochemical impedance spectroscopy, PEIS) are shown, which depend on the cross-linking degree of the copolymer ionomer, temperature and base composition.

[0046] Fig.12 The results show that the x-PDTP-Pr-10 anion exchange membrane has good conductivity at 60 °C, 1 M KOH solution and different current densities (0.5 A cm -2 , 1.0A cm -2 , 1.5A cm -2 ) conditions. DETAILED DESCRIPTION

[0047] A propargyl-grafted poly(arylpiperidinium) copolymer ionomer, a cross-linked anion exchange membrane and a preparation method thereof according to the present disclosure will be described in detail below.

[0048] The present disclosure provides a propargyl-grafted poly(arylpiperidinium) copolymer ionomer, a repeating unit of which is represented by <Chemical Formula 1>.

[0049] <Chemical Formula 1>

[0050]

[0051] In Chemical Formula 1, the aryl group is two or more different compounds selected from compounds represented by the following structural formulas:

[0052]

[0053] As shown in Chemical Formula 1, the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to the present disclosure substantially does not contain an aryl ether group in the polymer backbone, but has excellent film-forming ability and chemical and thermal stability due to the grafted propargyl group and the presence of the piperidinium group.

[0054] In addition, ion conductivity, mechanical properties, dimensional stability and durability are greatly improved. In particular, when forming an anion exchange membrane, the water content and expansion rate are reduced because the hydrophobicity is improved due to the cross-linked structure formed after heat treatment through the propargyl group.

[0055] In addition, the present disclosure provides a method for preparing a poly(arylpiperidinium) copolymer ionomer grafted with a propargyl group, comprising: (I) a step of dissolving (a) two or more different compounds represented by the following structural formula as monomers, and (b) 1-methyl-4-piperidone in an organic solvent to form a solution; (II) a step of slowly adding a strong acid catalyst to the solution, and stirring and reacting the reaction mixture to obtain a viscous solution; (III) a step of precipitating, washing and drying the viscous solution to obtain a solid polymer; (IV) a step of adding potassium carbonate, propargyl bromide and excess methyl halide to a polymer solution formed by dissolving the solid polymer in an organic solvent and reacting to form a quaternary piperidinium salt grafted with a propargyl group; and (V) a step of precipitating, washing and drying the mixed solution.

[0056]

[0057] The organic solvent in the step (I) may be one or more halogen-based solvents selected from the group consisting of dichloromethane, chloroform, dichloroethane, dibromomethane and tetrachloroethane. Specifically, dichloromethane may be used.

[0058] The strong acid catalyst in the step (II) can be trifluoroacetic acid, trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoro-1-propanesulfonic acid, perfluoropropionic acid, heptafluorobutyric acid or a mixture thereof.

[0059] The organic solvent in step (IV) can be N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide or dimethylformamide.

[0060] In the step (IV), the polymer reacts with a methyl halide to form a quaternary piperidinium salt. The methyl halide may be methyl fluoride, methyl chloride, methyl bromide or methyl iodide. Specifically, methyl iodide may be used.

[0061] In addition, the present disclosure provides an anion exchange membrane, which is formed by cross-linking the poly(arylpiperidinium) copolymer grafted with propargyl groups through an ion polymer.

[0062] The anion exchange membrane according to the present disclosure not only greatly improves mechanical durability, but also increases alkaline stability. In particular, when applied to alkaline fuel cells or water electrolysis devices, it can promote the interaction between the catalyst layer and the anion exchange membrane, exhibit a lower contact resistance, and stabilize the catalyst layer. Therefore, the cross-linked anion exchange membrane based on the poly (aryl piperidinium) copolymer ion polymer grafted with propargyl groups disclosed in the present disclosure has excellent alkaline fuel cell performance or water electrolysis performance, and has excellent durability due to high electrochemical stability.

[0063] In addition, the present disclosure provides a method for preparing a cross-linked anion exchange membrane, comprising: (i) dissolving the propargyl-grafted poly(arylpiperidinium) copolymer ion polymer in an organic solvent to form a polymer solution; (ii) casting the polymer solution on a glass plate and heating to remove the organic solvent to obtain a dry membrane; (iii) heat-treating the dry membrane to obtain a membrane in which a cross-linking reaction is induced; and (iv) treating the dry membrane with 1M NaHCO 3 Or the step of treating the obtained membrane with 1 M NaOH, washing it several times with ultrapure water, and drying it.

[0064] The organic solvent in step (i) may be N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide or dimethylformamide.

[0065] In addition, the concentration of the polymer solution may be specifically 2 wt % to 30 wt %, more specifically 3.0 wt % to 5.0 wt %. If the concentration of the polymer solution is lower than 2 wt %, the film-forming ability will decrease, and if it exceeds 30 wt %, the viscosity will be too high, resulting in deterioration of the film properties after film formation.

[0066] In addition, in step (ii), the organic solvent is slowly removed in an oven at 80° C. to 90° C. for 24 hours to obtain a dried membrane. Next, in step (iii), the dried membrane is heat-treated in a dark vacuum atmosphere at 160° C. to 180° C. for 120 to 240 minutes to complete the cross-linking reaction after the trimerization reaction and the coupling reaction are initiated to obtain an anion exchange membrane.

[0067] The synthesis process of the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to the present disclosure can be represented by Scheme 1.

[0068]

[0069] Scheme 1. Synthesis of propargyl-grafted poly(arylpiperidinium) copolymer ionomer (aryl group has the same definition as in Chemical Formula 1)

[0070] In addition, the present disclosure provides an alkaline fuel cell comprising the cross-linked anion exchange membrane.

[0071] In addition, the present disclosure provides a water electrolysis device comprising the cross-linked anion exchange membrane.

[0072] In addition, the present disclosure provides a supercapacitor comprising the cross-linked anion exchange membrane.

[0073] In addition, the present disclosure provides a carbon dioxide reduction device, which includes the cross-linked anion exchange membrane.

[0074] In addition, the present disclosure provides a redox flow battery including the cross-linked anion exchange membrane.

[0075] Hereinafter, embodiments and comparative examples according to the present disclosure are described in detail with reference to the accompanying drawings.

[0076] [Example]

[0077] [Synthesis Examples 1 to 3] Preparation of propargyl-grafted poly(arylpiperidinium) copolymer ionomer

[0078] Diphenylethane (1.0252 g, 5.625 mmol), terphenyl (3.885 g, 16.875 mmol) and 1-methyl-4-piperidone (2.8005 g, 24.750 mmol) were placed in a 100 mL reactor as monomers, and then dichloromethane (DCM, 18 mL) was added to dissolve each monomer and the mixture was stirred to form a solution. The solution was cooled to 1 ° C, and then a mixture of trifluoroacetic acid (trifluoroacetic acid, TFA, 2.7 mL) and trifluoromethanesulfonic acid (trifluoromethanesulfonic acid, TFSA, 18 mL) was slowly added to the solution, and the reaction was stirred for 12 hours to obtain a viscous solution. The viscous solution was poured into 500 mL of distilled water, precipitated, washed with deionized water several times, and then dried in an oven at 70 ° C for 24 hours to prepare a solid poly (diphenyl-co-terphenyl-N-methylpiperidine) polymer (PDTM) (yield 95.3%).

[0079] Then, the prepared PDTM (7.247 g) was dissolved in dimethyl sulfoxide (100 mL) to obtain a transparent polymer solution. Then, potassium carbonate (5.4 g) and propargyl bromide (0.5579 g) were added to the polymer solution, and the mixture was stirred continuously at room temperature for 24 hours. Then, methyl iodide (CH3I, 4.6 g) was added to the polymer solution, and the reaction was carried out at room temperature in a dark room for 24 hours to generate a quaternary piperidinium salt. Then, the mixed solution was precipitated in 500 mL of ethyl acetate, filtered, washed several times with deionized water, and dried in a vacuum oven at 45° C. for 24 hours to prepare a solid poly (aryl piperidinium) copolymer ion polymer grafted with propargyl, named PDTP-Pr-10 (grafting rate 10%, Synthesis Example 1).

[0080] In addition, propargyl-grafted poly(arylpiperidinium) copolymer ionomers were prepared in the same manner as in Synthesis Example 1, except that the grafting rate of 10% was controlled at 30% and 50% by adjusting the content of propargyl bromide to 30% and 50% during the reaction. They were named PDTP-Pr-30 (Synthesis Example 2) and PDTP-Pr-50 (Synthesis Example 3), respectively.

[0081] [Synthesis Examples 4 to 6] Preparation of propargyl-grafted poly(arylpiperidinium) copolymer ionomers

[0082] The propargyl-grafted poly(arylpiperidinium) copolymer ionomers were prepared by the same method as in Synthesis Examples 1 to 3, except that triptycene, biphenyl and 9,9'-dimethylfluorene were used instead of diphenylethane and terphenyl as monomers. They were named Trip-PFBP-Pr-10 (grafting rate 10%, Synthesis Example 4), Trip-PFBP-Pr-30 (grafting rate 30%, Synthesis Example 5) and Trip-PFBP-Pr-50 (grafting rate 50%, Synthesis Example 6), respectively.

[0083] [Preparation Examples 1 to 6] Preparation of Crosslinked Anions Using Propargyl-Grafted Poly(arylpiperidinium) Copolymer Ionomers Ion exchange membrane

[0084] Each of the poly(arylpiperidinium) copolymer grafted with propargyl groups obtained in Synthesis Examples 1 to 6 was dissolved in dimethyl sulfoxide to form a 5 wt% polymer solution. Next, the polymer solution was filtered with a PTFE filter (pore size 1 μm), cast on a glass plate, dried in a vacuum oven at 80° C. for 24 hours, and then peeled off from the glass plate to obtain a transparent film. The dried film was heat-treated at 170° C. for 120 to 240 minutes in a dark vacuum atmosphere to obtain a film in which a cross-linking reaction was induced. The prepared membranes were named x-PDTP-Pr-10 (Preparation Example 1), x-PDTP-Pr-30 (Preparation Example 2), x-PDTP-Pr-50 (Preparation Example 3), x-Trip-PFBP-Pr-10 (Preparation Example 4), x-Trip-PFBP-Pr-30 (Preparation Example 5) and x-Trip-PFBP-Pr-50 (Preparation Example 6).

[0085] The obtained I - The membrane was immersed in a 1 M NaOH aqueous solution at 60 °C for 24 h to convert the counter ions into OH - , washed several times with ultrapure water, and then dried to obtain a cross-linked anion exchange membrane.

[0086] [Preparation Example 7] Preparation of a membrane electrode assembly having a cross-linked structure assembly, MEA)

[0087] A catalyst containing a grafted propargyl poly(arylpiperidinium) copolymer ion polymer Trip-PFBP-Pr-m (m and x are the grafting rate and crosslinking degree, 10%, 30% or 50%) was sprayed on the PDTP-Pr-x anion exchange membrane to form a catalyst-coated membrane (CCM). The membrane electrode assembly was heat treated at 170°C for 120 to 240 minutes in a dark vacuum atmosphere to induce trimerization and coupling reactions, and then a crosslinking reaction was performed. The obtained I - The membrane electrode assembly was immersed in a 1 M KOH aqueous solution at 60 °C for 24 h to convert the counter ions into OH - The membrane was then washed with ultrapure water for several times and dried to prepare a membrane electrode assembly (MEA) with a cross-linked structure.

[0088] [Comparative Example 1] Preparation of poly(arylpiperidinium) copolymer ionomer and anion exchange membrane without propargyl group

[0089] A poly(diphenyl-co-terphenyl dimethylpiperidinium) copolymer ionomer was synthesized in the same manner as in Synthesis Example 1, except that propargyl bromide was not used as a reactant; and an anion exchange membrane was prepared therefrom in the same manner as in Preparation Example 1, and was named PDTP.

[0090] [Comparative Example 2] Preparation of poly(arylpiperidinium) copolymer ionomers without propargyl groups

[0091] A triptycene poly(fluorene-co-biphenyl dimethylpiperidinium) copolymer ion polymer was synthesized by the same method as in Synthesis Example 4, except that propargyl bromide was not used as a reactant; and an anion exchange membrane was prepared therefrom by the same method as in Preparation Example 4, and was named Trip-PFBP.

[0092] [Test example]

[0093] Test data such as mechanical properties, moisture content, expansion ratio, fuel cell performance, etc. of the anion exchange membranes prepared in the preparation examples and comparative examples of the present disclosure were measured and evaluated by the method described in Korean Patent Publication No. 10-2021-0071810 filed by the inventors of the present disclosure.

[0094] first, Figure 1 The poly(arylpiperidinium) copolymer ionomers Trip-PFBP-Pr-m series and PDTP-Pr-m series (m is 10, 30 or 50) grafted with propargyl groups obtained in Synthesis Examples 1 to 6 of the present disclosure are shown. 1 H NMR spectroscopy.

[0095] like Figure 1As shown, the characteristic peak of methylene hydrogen derived from propargyl appears at about 4.5 ppm, which means that the grafting reaction is successfully carried out. The grafting rate is calculated as the integrated ratio of methylene hydrogen atoms at about 4.5 ppm to aromatic hydrogen atoms at about 7.0 ppm to 7.8 ppm.

[0096] also, Figure 2 The (A) moisture content and (B) expansion rate of the cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30 or 50) in Preparation Examples 1 to 6 of the present disclosure after heat treatment at 170°C for 0 minutes, 120 minutes and 240 minutes, respectively. It can be seen that the moisture content and expansion rate decrease rapidly with the composition of the cross-linked structure and the cross-linking time.

[0097] In addition, FT-IR analysis was also performed to confirm whether the cross-linked anion exchange membrane series obtained in Preparation Examples 1 to 6 of the present disclosure had undergone a cross-linking reaction. Figure 3 The analysis results of the change of the cross-linking degree of the anion exchange membrane x-PDTP-Pr-50 prepared in Preparation Example 3 of the present disclosure as a function of heat treatment time are shown [A: FT-IR spectrum of the x-PDTP-Pr-50 anion exchange membrane as a function of heat treatment time; B: residual propargyl groups in the x-PDTP-Pr-50 anion exchange membrane as a function of heat treatment time (calculated by integrating the peak of the propargyl groups in the FT-IR spectrum)].

[0098] like Figure 3 As shown in A, 2120cm -1 The absorption peak nearby is due to the stretching vibration of acetylenic hydrocarbons. As the heat treatment time increases, the intensity of the absorption peak decreases, which means that the propargyl group is consumed during the heat treatment.

[0099] In addition, if Figure 3 As shown in Figure B, when the heat treatment time is shorter than 80 minutes, most of the propargyl groups remain unreacted, while when the heat treatment time is longer than 120 minutes, about 70% of the propargyl groups react, indicating that the crosslinking reaction proceeds successfully. Therefore, the critical heat treatment time is 120 minutes or longer. In the present disclosure, it is preferred to perform the heat treatment within 120 minutes to 240 minutes.

[0100] also, Figure 4 The contact angles of the cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30, 50) prepared in Preparation Examples 1 to 6 of the present disclosure and PDTP and Trip-PFBP prepared in Comparative Examples 1 and 2 after heat treatment at 170°C for 120 minutes are shown. It can be seen that the water contact angle increases with the increase in the degree of cross-linking, which indicates an increase in hydrophobicity.

[0101] also, Figure 5 The thermogravimetric analysis (thermogravimetric) of the trip-PFBP-Pr-m series and the PDTP-Pr-m series (before heat treatment) prepared in the synthesis examples 1 to 6 of the present disclosure, and the cross-linked anion exchange membranes x-trip-PFBP-Pr-m series and the x-PDTP-Pr-m series prepared in the preparation examples 1 to 6 after heat treatment at 170°C for 120 minutes is shown. Analysis, TGA) results (m is 10, 30 or 50) [A. Trip-PFBP-Pr-10 and x-Trip-PFBP-Pr-10, B: Trip-PFBP-Pr-30 and x-Trip-PFBP-Pr-30, C: Trip-PFBP-Pr-50 and x-Trip-PFBP-Pr-50, D: PDTP-Pr-10 and x-PDTP-Pr-10, E: PDTP-Pr-30 and x-PDTP-Pr-30, F: PDTP-Pr-50 and x-PDTP-Pr-50]. It can be confirmed that the cross-linked anion exchange membrane obtained after heat treatment has higher thermal stability than the copolymer ion polymer before heat treatment.

[0102] also, Figure 6 The cross-linked anion exchange membranes x-Trip-PFBP-Pr-m series and x-PDTP-Pr-m series (m is 10, 30 or 50) prepared in Preparation Examples 1 to 6 of the present disclosure are shown in Figure 2 after heat treatment at 170°C for 0 minutes, 120 minutes and 240 minutes, respectively. 3 2- Conductivity (30°C). As the crosslinking time increases, the conductivity tends to decrease. In particular, when the crosslinking time exceeds 240 minutes, the conductivity decreases rapidly. Therefore, from the perspective of ensuring good conductivity, a crosslinking time of 120 minutes to 240 minutes is more desirable.

[0103] also, Figure 7 The peel strength of the catalyst coating membrane and the anion exchange membrane depending on the type of copolymer ionomer is shown.

[0104] A comparative membrane electrode assembly (MEA) was prepared using the Trip-PFBP and PDTP obtained in Comparative Examples 1 and 2, and the 180° peel strength of the MEA was recorded using a universal testing machine (UTM).

[0105] like Figure 7As shown in Figure 2, the peel strength of the membrane electrode assembly based on x-Trip-PFBP-Pr-x ionomer is much higher than that of the membrane electrode assembly based on PDTP and Trip-PFBP (membrane and ionomer). In particular, the peel strength of the membrane electrode assembly based on x-Trip-PFBP-Pr-50 is 1.15N mm -1 , which is about twice that of the membrane electrode assemblies based on PDTP and Trip-PFBP. The high peel strength of the membrane electrode assembly indicates that the interaction between the catalyst layers is stronger. In other words, it is confirmed that the presence of the cross-linked structure can effectively improve the stability of the catalyst layer of the membrane electrode assembly.

[0106] Figures 8a to 8d The electrochemical stability data of the catalyst layer analyzed by rotating disk electrode (RDE) test [transmission electron microscopy image, average nanoparticle size, linear sweep voltammogram (LSV) of oxygen reduction reaction of catalysts of different ionic polymers (A: Trip-PFBP, B: x-Trip-PFBP-10, C: x-Trip-PFBP-30, D: x-Trip-PFBP-50)] are shown.

[0107] After the durability test, the half-wave potential of the Trip-PFBP and Pt / C catalysts dropped from 0.683V to 0.843V. It is speculated that this is caused by the loss of ionic polymers and the aggregation of catalyst particles. To verify this, the microscopic morphology of the catalysts was observed using a high-resolution transmission electron microscope. After it test, the Pt particles aggregated into larger sizes. Specifically, the average particle size of the Trip-PFBP and Pt / C catalysts increased from 3.7nm to 4.4nm after the durability test, indicating that their stability is low. In contrast, the ORR LSV performance of the catalyst based on the x-Trip-PFBP-Pr-m ionic polymer is much more stable. The attenuation of the half-wave potential is less than 11mV. At the same time, the aggregation of Pt particles was also significantly suppressed. Specifically, the average particle size of the x-Trip-PFBP-Pr-10, 30 and 50 ionic polymer catalysts increased from 3.36nm to 3.62nm (B in Figures 8A to 8D), from 3.17nm to 3.41nm ( Figures 8a to 8d The C in Figure 1 and the average particle size of the PFBP catalyst increased from 3.37 nm to 3.46 nm, which is much smaller than the average particle size of the PFBP catalyst (increased from 3.7 nm to 4.4 nm). This suggests that the cross-linked structure can stabilize the energy device by fixing the catalyst particles.

[0108] also, Fig. 9 The performance of the fuel cell is shown to be dependent on the degree of crosslinking of the copolymer ionomer and the anion exchange membrane.

[0109] The peak power density (PPD) of the fuel cell based on x-Trip-PFBP-Pr-10 and x-Trip-PFBP-Pr-30 ionomers reached 1.0 W cm without back pressure. -2 or higher, is a fuel cell based on x-Trip-PFBP-Pr-50 ionomer (PPD of 0.502 W cm -2 ). The improvement in peak power density is attributed to the high ionic conductivity of x-Trip-PFBP-Pr-10 and x-Trip-PFBP-Pr-30. In addition, the fuel cell based on x-PDTP-Pr-10 AEM has better PPD than x-PDTP-Pr-30 and x-PDTP-Pr-50 due to its higher water uptake (WU) and conductivity.

[0110] Fig.10 Results are shown for measuring the in situ durability of a fuel cell based on the anion exchange membrane x-PDTP-Pr-10 using an asymmetric copolymer ionomer.

[0111] Long-term stability testing over 1000 hours showed that the HFR (High Frequency Impedance) of the fuel cell can be recovered after the replenishment process, indicating that the ohmic loss is caused by reasons other than chemical degradation of the membrane and ionomer (e.g., carbonization or uneven water distribution). These results indicate that improving the interaction between the AEM and the catalyst layer is an effective way to extend the life of the anion exchange membrane fuel cell.

[0112] Fig.11 The water electrolysis performance (linear sweep voltammogram, LSV) and the resistance (potentiostatic electrochemical impedance spectroscopy, PEIS) are shown, which depend on the cross-linking degree of the copolymer ionomer, temperature and base composition.

[0113] In 1 M KOH solution, the AEMWE based on x-Trip-PFBP-Pr-10 ionomer has the highest current density, reaching 14.34 A cm -2 @2.0V, R ohm The value is lower, 22.58MΩcm -2 , R charge The value is 12.28mΩcm -2When using x-Trip-PFBP-Pr-30 ionomer, the water electrolysis performance decreased (11.9 A cm -2 @2.0V), which is believed to be due to the low water absorption capacity of the anode ionomer due to the use of a dry anode. Asymmetric ionomers were used in the electrolytic performance and durability tests, and x-Trip-PFBP-Pr-10 and x-Trip-PFBP-Pr-30 were used as the positive electrode ionomers. When using asymmetric ionomers, 15.17A cm was achieved at 80°C -2 The improvement of current density. ohm and R charge The current density naturally decreases with increasing temperature. Due to the conductivity (0.01M KOH 66mΩcm -2 vs.1M KOH 23mΩcm - 2 R charge ) and electroactivity (0.01M KOH 79mΩcm -2 vs.1M KOH 10mΩcm -2 R charge ) was enhanced, and the AEMWE operated in concentrated alkaline solution showed a higher current density. Nevertheless, the performance of the AEMWE operated in 0.1 M KOH solution was still much superior.

[0114] also, Fig.12 The results show that the x-PDTP-Pr-10 anion exchange membrane has good conductivity at 60 °C, 1 M KOH solution and different current densities (0.5 A cm -2 , 1.0A cm -2 , 1.5A cm -2 ) conditions.

[0115] like Fig.12 As shown, at 0.5A cm -2 The initial voltage of AEMWE under operation was low, 1.63 V, and the voltage drop rate was 88 μV h-1 within 1000 h. -1 When the current density increases to 1.0 A cm -2 When the AEMWE voltage increases naturally to 1.70 V, it also exhibits a 98 μV h -1 The low voltage drop rate indicates its excellent stability.

[0116] 1.5A cm -2This is a rather harsh condition for the long-term operation of AEMWE, because it will generate a large number of oxygen bubbles in a short period of time, which will cause the catalyst layer to collapse. However, the AEMWE using the catalyst layer obtained in Preparation Example 7 of the present disclosure can operate at 1.5 A cm -2 More importantly, the AEMWE operating under these harsh conditions also showed an excellent Faradaic efficiency of 95% or more during the test, indicating that the membrane electrode assembly has high gas robustness. These results show that stabilizing the catalyst layer by thermal cross-linking is a promising method to improve the performance and stability of AEMWE.

Claims

1. A propargyl-grafted poly(arylpiperidinium) copolymer ionomer having a repeating unit represented by <Chemical Formula 1>: <Chemical Formula 1> Wherein the aryl group is two or more different compounds selected from the compounds represented by the following structural formulas:

2. A method for preparing a propargyl-grafted poly(arylpiperidinium) copolymer ionomer, include: (I) a step of dissolving (a) two or more different compounds represented by the following structural formula as monomers, and (b) 1-methyl-4-piperidone in an organic solvent to form a solution; (II) slowly adding a strong acid catalyst to the solution and stirring the reaction mixture to obtain a viscous solution; (III) a step of precipitating, washing and drying the viscous solution to obtain a solid polymer; (IV) adding potassium carbonate, propargyl bromide and an excess of methyl halide to a polymer solution in which the solid polymer is dissolved in an organic solvent and reacting the solution to form a quaternary piperidinium salt grafted with a propargyl group; and (V) The steps of precipitating, washing and drying the mixed solution.

3. The method for preparing the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to claim 2, in, The organic solvent in the step (I) is one or more halogen-based solvents selected from the group consisting of dichloromethane, chloroform, dichloroethane, dibromomethane and tetrachloroethane.

4. The method for preparing the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to claim 2, in, The strong acid catalyst in the step (II) is trifluoroacetic acid, trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoro-1-propanesulfonic acid, perfluoropropionic acid, heptafluorobutyric acid or a mixture thereof.

5. The method for preparing the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to claim 2, in, The organic solvent in step (IV) is N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide or dimethylformamide.

6. The method for preparing the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to claim 2, in, The methyl halide in step (IV) is methyl fluoride, methyl chloride, methyl bromide or methyl iodide.

7. An anion exchange membrane, formed by cross-linking the propargyl-grafted poly(arylpiperidinium) copolymer of claim 1.

8. A method for preparing an anion exchange membrane, include: (i) dissolving the propargyl-grafted poly(arylpiperidinium) copolymer ionomer according to claim 1 in an organic solvent to form a polymer solution; (ii) casting the polymer solution on a glass plate and heating to remove the organic solvent to obtain a dry film; (iii) a step of heat-treating the dried film to obtain a film in which a cross-linking reaction is induced; and (iv) 1M NaHCO 3 Alternatively, the obtained membrane is treated with 1 M NaOH, washed several times with ultrapure water, and then dried.

9. The method for preparing anion exchange membrane according to claim 8, in, The concentration of the polymer solution is 2-30 wt%.

10. The method for preparing anion exchange membrane according to claim 8, in, The heat treatment in step (iii) is performed at 160° C. to 180° C. for 120 to 240 minutes in a dark vacuum atmosphere to complete the cross-linking reaction after initiating the trimerization reaction and the coupling reaction.

11. An alkaline fuel cell comprising the anion exchange membrane according to claim 7.

12. A water electrolysis device comprising the anion exchange membrane according to claim 7.

13. A supercapacitor comprising the anion exchange membrane according to claim 7.

14. A carbon dioxide reduction device comprising the anion exchange membrane according to claim 7.

15. A redox flow battery comprising the anion exchange membrane according to claim 7.

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