Ion-conductive polymer electrolyte membrane and method for manufacturing the same

Abstract

The present invention relates to an ion-conducting polymer electrolyte membrane and a method for manufacturing the same. Specifically, the ion-conducting polymer electrolyte membrane of the present invention comprises an ion-conducting polymer having a repeating unit of a styrene derivative in which an ionic functional group is introduced at a specific position of a benzene ring, thereby providing an ion-conducting polymer electrolyte membrane having excellent conductivity and a wide electrochemical stability window. Furthermore, a lithium-sulfur battery having excellent capacity and low polarization characteristics can be provided by including the ion-conducting polymer electrolyte membrane.

Description

Technology Field

[0001] The present invention relates to an ion-conducting polymer electrolyte membrane and a method for manufacturing the same. Background Technology

[0002] Ion-conducting polymer electrolyte membranes are critically used in various electrochemical devices, such as fuel cells, secondary batteries, sensors, and ion exchange membranes, and play a role in improving the stability and efficiency of these devices by allowing ions to pass through while blocking electrons.

[0003] Nafion®, a perfluorinated polymer, has been used as a representative electrolyte membrane material due to its excellent ionic conductivity and chemical resistance. However, Nafion has problems such as a complex synthesis process, high manufacturing costs, and reduced conductivity due to decreased moisture retention at high temperatures. In addition, there are difficulties in the treatment and degradation of fluorinated polymers from an environmental perspective, so the development of alternative materials is required.

[0004] Against this backdrop, polymer electrolyte membranes in which ion-conducting functional groups, such as sulfonic acid groups (-SO3H), are introduced into styrene-based aromatic polymers are attracting attention. While these membranes offer advantages in terms of structural design freedom, process simplicity, and cost efficiency, they have limitations in maintaining high-temperature stability and mechanical properties. Furthermore, since physical properties vary significantly depending on the substitution positions and patterns of the functional groups, structural control technology is required. Prior art literature

[0005] Korean Published Patent Application No. 10-1997-0067985 (October 13, 1997) The problem to be solved

[0006] The present invention aims to provide an ion-conducting polymer electrolyte membrane having excellent conductivity and a wide electrochemical stability window by comprising an ion-conducting polymer having a repeating unit of a styrene derivative in which an ionic functional group is introduced at a specific position of a benzene ring.

[0007] In addition, the present invention aims to provide a lithium-sulfur battery having excellent capacity and low polarization, comprising the above-mentioned ion-conducting polymer electrolyte membrane. means of solving the problem

[0008] The present invention relates to an ionic liquid; and

[0009] The present invention provides an ion-conducting polymer electrolyte membrane comprising an ion-conducting polymer composed of repeating units represented by the following chemical formula 1.

[0010] [Chemical Formula 1]

[0011]

[0012] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0013] In one embodiment, the ionic liquid may be any one or more mixtures selected from the group consisting of cationic liquids, anionic liquids, and neutral liquids.

[0014] In one embodiment, the ionic liquid may comprise an ion pair selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations.

[0015] In one embodiment, the number average molecular weight of the ion-conducting polymer may be 1,000 to 50,000 g / mol.

[0016] In one embodiment, the polydispersity index (PDI) of the ion-conducting polymer may be 1.00 to 1.20.

[0017] In one embodiment, the above ion-conducting polymer 1 The degree of polymerization (DP) measured by H NMR spectroscopy may be 2 to 200.

[0018] In one embodiment, the ion-conducting polymer may be composed of repeating units represented by the following chemical formula 2.

[0019] [Chemical Formula 2]

[0020]

[0021] In the above chemical formula 2, R1 is -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0022] In one embodiment, the shear modulus of the ion-conducting polymer electrolyte membrane is 1.0 × 10⁻⁶ 2 Up to 1.0 × 10 8 It could be Pa.

[0023] In one embodiment, the ion-conducting polymer electrolyte membrane has an ion conductivity of 1.0 × 10⁻⁶ at room temperature (23±5 ℃). -2 It may be greater than mS / cm.

[0024] In one embodiment, the glass transition temperature (T) of the ion-conducting polymer electrolyte membrane g ) may be -50 to 100 ℃.

[0025] Another aspect of the present invention provides a lithium-sulfur battery comprising the ion-conducting polymer electrolyte membrane.

[0026] Another aspect of the present invention comprises the step of preparing a mixed solution by mixing an ionic conductive polymer composed of repeating units represented by the following chemical formula 1 with an ionic liquid;

[0027] A step of freeze-drying the above mixed solution at -100 to -10 ℃ to remove the solvent and obtaining an ion-conductive polymer electrolyte;

[0028] The present invention provides a method for manufacturing an ion-conducting polymer electrolyte membrane comprising the step of manufacturing an ion-conducting polymer electrolyte membrane by compressing or molding the above ion-conducting polymer electrolyte.

[0029] [Chemical Formula 1]

[0030]

[0031] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0032] In one embodiment, the ionic liquid may be included with the substituent of the polymer in an equivalent ratio of 0.1 to 1:1. Effects of the invention

[0033] An ion-conducting polymer electrolyte membrane according to one embodiment of the present invention comprises an ion-conducting polymer having a repeating unit of a styrene derivative in which an ionic functional group is introduced at a specific position of a benzene ring, thereby having excellent ion conductivity and broad electrochemical stability.

[0034] In addition, the lithium-sulfur battery including the above-mentioned ion-conducting polymer electrolyte membrane can have excellent capacity and low polarization. Brief explanation of the drawing

[0035] Figure 1 shows b) of O-[3-(dimethylcarbamothioyloxy)-5-formylphenyl] N,N-dimethylcarbamothioate synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 2 shows b) of S-[3-(dimethylcarbamoylsulfonyl)-5-formylphenyl]N,N-dimethylcarbamothioate synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 3 shows b) of 1-({3-[(dimethylcarbamoyl)sulfonyl]-5-(1,3-dioxolane-2-yl)phenyl}sulfonyl)-N,N-dimethylformamide synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 4 shows b) of sodium 5-(1,3-dioxolane-2-yl)benzene-1,3-disulfonate synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 5 shows b) of sodium 5-formylbenzene-1,3-disulfonate synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 6 shows b) of 5-vinyl-1,3-benzenedisulfonic acid synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 7 shows b) of polystyrene-3,5-disulfite (PSdi35S) synthesized in the preparation example of the present invention 1 H NMR and c) 13 This is the C NMR spectrum. Figure 8 shows the viscoelastic properties of an ion-conducting polymer electrolyte membrane according to Example 3 of the present invention as measured with temperature change. In Figure 8, filled symbols represent the elastic response (Storage modulus; G'), and open symbols represent the viscous response (Loss modulus; G"). Figure 9 shows the viscoelastic properties of an ion-conducting polymer electrolyte membrane according to Example 4 of the present invention measured according to temperature change. FIG. 10 shows the ion-conducting polymer electrolyte membrane according to Examples 3 and 4 of the present invention measured by Differential Scanning Calorimetry (DSC) in a temperature range of -60 to 120 ℃. Figure 11 shows the temperature-dependent conductivity characteristics of ion-conducting polymer electrolyte membranes according to Example 1 and Comparative Example 1 of the present invention as an Arrhenius plot. FIG. 12 shows a Linear Sweep Voltammetry (LSV) graph of an ion-conducting polymer electrolyte membrane according to Example 1 and Comparative Example 1 of the present invention. FIG. 13 shows the voltage-capacity curves of a coin cell according to Example 1 and Comparative Example 1 of the present invention. Figure 14 shows a linear scanning voltage graph of an ion-conducting polymer electrolyte membrane according to Example 2 and Comparative Example 2 of the present invention. FIG. 15 shows the voltage-capacity curves of a coin cell according to Example 2 and Comparative Example 2 of the present invention. Specific details for implementing the invention

[0036] The present invention will be described in more detail below. However, the following specific examples or embodiments are merely references for the detailed explanation of the present invention and are not limited thereto, and the present invention may be implemented in various forms.

[0037] Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as generally understood by one of the art to which the present invention pertains. The terms used in the description of the present invention are merely for the purpose of effectively describing specific embodiments and are not intended to limit the present invention.

[0038] Additionally, the singular form used in the specification and the appended claims may be intended to include the plural form unless specifically indicated otherwise in the context.

[0039] Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] Furthermore, unless otherwise specifically defined in the present invention, when a layer or member is described as being located “on” another layer or member, this includes not only cases where a layer or member is in contact with another layer or member, but also cases where another layer or member exists between two layers or two members.

[0041] Additionally, terms used herein such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said sense, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0042] In addition, in the chemical formulas of this specification, the * symbol is used to indicate a variable part that is not part of a fixed structure within a repeating unit, and indicates that the position in the chemical structure can change or be combined in various forms (such as specific substituents or groups).

[0043] The present invention will be described below.

[0044] The present invention relates to an ionic liquid; and

[0045] The present invention provides an ion-conducting polymer electrolyte membrane comprising an ion-conducting polymer composed of repeating units represented by the following chemical formula 1.

[0046] [Chemical Formula 1]

[0047]

[0048] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0049] In one embodiment, the ionic liquid may be a mixture of one or more selected from the group consisting of cationic liquids, anionic liquids, and neutral liquids.

[0050] The above cationic liquid may be any one or more mixtures selected from the group consisting of imidazolium-based, pyrrolidinium-based, and piperidinium-based ionic compounds, but is not limited thereto.

[0051] The above anionic liquid is trifluoroacetate ([TFA] - ), trifluoromethanesulfonate (Trifluoromethanesulfonate; [CF3SO3] - ), bis(fluorosulfonyl)imide ([N(SO2F)2] - ), Bis(Trifluoromethanesulfonyl)Imide ([N(SO2CF3)2] - ), dicyanamide (Dicyanamide; [N(CN)2] - ), tetracyanoborate (Tetracyanoborate; [B(CN)4] - ), Dihydrogenphosphate (Dihydrogenphosphate; [H2PO4] - ), hexafluorophosphate (Hexafluorophosphate; [PF6] - ) and hydrogen sulfate (Hydrogen Sulfate; [HSO4] - It may be any one or more mixtures selected from the group consisting of ), but is not limited thereto.

[0052] The above neutral liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMTFSI), 1-methyl-3-propylimidazolium iodide (PMI), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMTF), 1-ethyl-3-methylimidazolium hydrogensulfate (EMIHSO4), and 1-ethyl-3-methylimidazolium It may be any one or more mixtures selected from the group consisting of trifluoromethanesulfonate (1-ethyl-3-methylimidazolium trifluoromethanesulfonate, EMITf) and N-methyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYRTFSI), but is not limited thereto.

[0053] In one embodiment, the ionic liquid may comprise an ion pair selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations.

[0054] The above metal ion is copper (Cu 2+ ), zinc (Zn 2+ ), Iron (Fe 2+ / Fe 3+ ), manganese (Mn 2+ / Mn 3+ ), Aluminum (Al 3+ ) and calcium (Ca 2+It may be a metal ion such as ), but is not limited thereto.

[0055] The above organic cations may be ammonium ions, pyridinium ions, benzyl ammonium ions, trimethylamine ions, and ethyldiamine ions, but are not limited thereto.

[0056] In one embodiment, the number average molecular weight of the ion-conducting polymer may be 1,000 to 50,000 g / mol, 2,000 to 25,000 g / mol, or 3,000 to 10,000 g / mol. An ion-conducting polymer having the number average molecular weight may have excellent mechanical strength and can withstand external pressure or physical stress well when used as a separation membrane. In addition, it may be advantageous for adsorption of ionic liquids, but is not limited thereto.

[0057] In one embodiment, the polydispersity index (PDI) of the ion-conducting polymer may be 1.00 to 1.20, 1.01 to 1.15, or 1.02 to 1.10. An ion-conducting polymer having the above polydispersity index range may maintain excellent ion conductivity by having a uniform ion transport pathway and low resistance. Additionally, it may be preferred as it may possess excellent mechanical strength and electrochemical stability, but is not limited thereto.

[0058] In one embodiment, the degree of polymerization (DP) of the ion-conducting polymer measured by 1H NMR spectroscopy may be 2 to 200, 5 to 100, or 10 to 50. An ion-conducting polymer having the above range of degrees of polymerization allows ions to move easily between molecules, which may be advantageous in terms of ion conductivity and rapid diffusion rate. In addition, it is preferred because it has excellent flexibility and mechanical strength, allowing it to be well adapted to mechanical stress or temperature changes within a battery cell, but is not limited thereto.

[0059] In one embodiment, the ion-conducting polymer may be composed of repeating units represented by the following chemical formula 2.

[0060] [Chemical Formula 2]

[0061]

[0062] In the above chemical formula 2, R1 is -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0063] In one embodiment, the ion-conducting polymer may be composed of repeating units represented by the following chemical formula 3.

[0064] [Chemical Formula 3]

[0065]

[0066] In the above chemical formula 3, n is 10 < n < 10,000.

[0067] In one embodiment, the ion-conducting polymer electrolyte membrane has an ion conductivity of 1.0 × 10⁻⁶ at room temperature (23±5 ℃). -2 Up to 1.0 × 10 1 mS / cm, 2.0 × 10 -2 to 5.0 mS / cm, 4.0 × 10 -2 Up to 1.0 mS / cm, 1.0 × 10 -1 It may be up to 1.0 mS / cm. An ion-conducting polymer electrolyte membrane having the above ion conductivity range is preferred because it allows for smooth ion movement within the electrolyte, improves the charge / discharge efficiency of the lithium-sulfur battery, and enhances battery performance, but is not limited thereto.

[0068] In one embodiment, the glass transition temperature (T) of the ion-conducting polymer electrolyte membrane g ) may be -50 to 100 ℃, -45 to 80 ℃, or -40 to 50 ℃. An ion-conducting polymer electrolyte membrane having the above glass transition temperature range is preferred because it offers high electrolyte stability and can consistently provide conductivity and electrochemical performance, but is not limited thereto. The above glass transition temperature range may vary depending on the ionic liquid used. For example, [PYR 13 In the case of an ion-conducting polymer electrolyte membrane prepared using a ][TFSI] ionic liquid and an ion-conducting polymer of the present invention, it may have a glass transition temperature range of 0 to 50 ℃, 10 to 30 ℃, and 15 to 20 ℃, and in the case of an ion-conducting polymer electrolyte membrane prepared using a PMpipFSI ionic liquid and an ion-conducting polymer of the present invention, it may have a glass transition temperature range of -20 to 10 ℃, -10 to 5 ℃, and -5 to 0 ℃.

[0069] In one embodiment, the shear modulus of the ion-conducting polymer electrolyte membrane is 1.0 × 10⁻⁶ 2 Up to 1.0 × 10 8 Pa, 2.0 × 10 2 Up to 5.0 × 10 7 Pa, 3.0 × 10 2 Up to 1.0 × 10 7 It may be Pa. Ion-conducting polymer electrolyte membranes having the above-mentioned shear modulus range are preferred because they can secure a balance of excellent mechanical stability and flexibility and are advantageous for controlling ion conductivity and interfacial properties, but are not limited thereto.

[0070] Another aspect of the present invention provides a lithium-sulfur battery comprising the ion-conducting polymer electrolyte membrane.

[0071] Another aspect of the present invention comprises the step of preparing a mixed solution by mixing an ionic conductive polymer composed of repeating units represented by the following chemical formula 1 with an ionic liquid;

[0072] A step of freeze-drying the above mixed solution at -100 to -10 ℃ to remove the solvent and obtaining an ion-conductive polymer electrolyte;

[0073] The present invention provides a method for manufacturing an ion-conducting polymer electrolyte membrane comprising the step of manufacturing an ion-conducting polymer electrolyte membrane by compressing or molding the above ion-conducting polymer electrolyte.

[0074] [Chemical Formula 1]

[0075]

[0076] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000.

[0077] In one embodiment, the ionic liquid may be included with the substituents of the polymer in an equivalent ratio of 0.1 to 1:1, 0.25 to 1:1, or 0.5 to 1:1. It is preferred to prepare an ion-conducting polymer electrolyte membrane by including the ionic liquid within the above equivalent ratio range, as this can improve conductivity while balancing the polymer and the ionic liquid, but it is not limited thereto.

[0078] The present invention will be explained in more detail below based on the following examples and comparative examples. However, the following examples and comparative examples are merely illustrative of the present invention and are not intended to limit the present invention.

[0079] [measurement method]

[0080] 1. Chemical Structure Analysis of Ion-Conducting Polymers

[0081] ion-conducting polymer 1 H and 13 Nuclear Magnetic Resonance (NMR) spectra were measured using a Bruker AVANCE-III 500 instrument. CDCl3, D2O, MeOD-d4, and DMSO-d6 were used as NMR solvents depending on the solubility of the sample.

[0082] 2. Molecular weight of ion-conducting polymers

[0083] The molecular weight and polydispersity of the ion-conducting polymer were measured and the degree of polymerization was calculated using aqueous gel permeation chromatography (GPC, Shimadzu 1 HPLC, H2O / MeOH containing 0.15 M NaNO3 (9 / 1, v / v), flow rate 1.0 mL / min). Polyethylene oxide was used as the reference material.

[0084] 3. Analysis of Conductivity Characteristics of Ion-Conducting Polymer Electrolyte Membranes According to Temperature

[0085] Ion-conducting polymer electrolyte membranes with a thickness of 0.1 to 0.4 mm were analyzed using an electrochemical impedance analyzer (VersaSTAT 3; Princeton Applied Research) at a temperature range of 20 to 120 °C, 1-10 6 Conductivity characteristics were analyzed in a glove box filled with Ar gas (anhydrous environment) under Hz conditions.

[0086] 4. Analysis of Viscoelastic Properties of Ion-Conducting Polymer Electrolyte Membranes According to Temperature

[0087] The elastic response (Storage modulus; G') and viscous response (Loss modulus; G") of an ion-conducting polymer electrolyte membrane with a diameter of 0.8 cm and a thickness of 0.5 mm were measured using a rheometer (Discovery TA DHR-2 rheometer; Waters) in a temperature range of 20 to 200 ℃ and are shown in Fig. 8.

[0088] The shear modulus was calculated using the following formula 1 and is shown in Table 2.

[0089] [Formula 1]

[0090] G = ((G') 2 + (G") 2 ) 1 / 2 ,

[0091] In the above formula 1, G is the shear modulus, G' is the storage modulus, and G" is the loss modulus.

[0092] 5. Evaluation of Oxidation Stability of Ion-Conducting Polymer Electrolyte Membranes

[0093] The electrochemical stability of the ion-conducting polymer electrolyte membrane was evaluated by performing linear sweep voltammetry (LSV) using an electrochemical measurement system (VersaSTAT 3 potentiostat; Princeton Applied Research) at room temperature (23±5 ℃) with a voltage range of 0 to 6 V and a voltage scan rate of 1.0 mV / s, and the results are shown in Figure 12.

[0094] 6. Measurement of Electrochemical Performance of Coin Cells

[0095] Using a battery cycling system (WBCS3000; Wonatech), charge / discharge tests were performed at room temperature (23±5 ℃) at a charge / discharge rate of 0.1 C under voltage ranges of 1.7 to 2.7 V or 1.0 to 3.0 V.

[0096] [Preparation Example]

[0097] 1. Preparation of ion-conductive polymers

[0098] 1) O -[3-(dimethylcarbamothioyloxy)-5-formylphenyl] N,N - Synthesis of dimethylcarbamothioate

[0099]

[0100] 3,5-dihydroxybenzaldehyde (3,5-DHBH, 10.0 g, 72.4 mmol) and anhydrous degassed dimethylformamide (DMF) (100 mL) were added to a two-necked flask (500 mL), mixed, and then cooled to 0 ℃. After stirring for 30 minutes, 1,4-diazabicyclo[2.2.2]octane (DABCO) (28.4 g, 253.4 mmol) was slowly added, followed by the dropwise addition of a solution of 5,5-dimethylthiazolidine-4-carboxylic acid (DMTC) (31.3 g, 253.3 mmol) dissolved in anhydrous degassed DMF (100 mL). The reaction mixture was stirred at room temperature under an argon atmosphere for 8 hours. After the reaction was complete, the product mixture was precipitated several times in 2 L of distilled water and vacuum dried to obtain a white powder. O -[3-(dimethylcarbamothioyloxy)-5-formylphenyl] N,N 19.3 g of dimethylcarbamothioate was obtained (yield 85.5%).

[0101] 1 H and 13 1C NMR (CDCl3, ppm): δ H = 9.97 (s, 1H), 7.47-7.51 (d, 2H), 7.10-7.15 (t, 1H), 3.46 (s, 6H), 3.36 (s, 6H) δ c = 190.19, 186.78, 154.60, 137.56, 124.40, 121.44, 43.48, 39.01 (See Fig. 1)

[0103] 2) S -[3-(dimethylcarbamoylsulfonyl)-5-formylphenyl] N,N - Synthesis of dimethylcarbamothioate

[0104]

[0105] In a single-neck flask (250 mL) O-[3-(dimethylcarbamothioyloxy)-5-formylphenyl] N,N ε-dimethylcarbamothioate (13.4 g, 42.9 mmol) and diphenyl ether (Ph2O, 67 mL) were added, and the mixture was heated to 240 °C under an argon atmosphere and stirred for 6 hours. During this process, a Newman-Kwart rearrangement reaction occurred, which was confirmed by dynamic NMR measurements. The reaction mixture was cooled and precipitated in n-hexane, followed by washing with n-hexane several times and vacuum drying. As a result, in the form of a gray solid S -[3-(dimethylcarbamoylsulfonyl)-5-formylphenyl] N,N 12.8 g of dimethylcarbamothioate was obtained, and the yield was 95.5%.

[0106] 1 H and 13 1C NMR (CDCl₃, ppm): δ H = 9.99 (s, 1H), 7.99-8.01 (d, 2H), 7.86-7.90 (t, 1H), 3.08 (brs, 6H), 3.02 (brs, 6H) δ C = 190.61, 165.59, 147.43, 137.29, 137.02, 131.22, 37.06 (See Fig. 2)

[0108] 3) 1-({3-[(dimethylcarbamoyl)sulfonyl]-5-(1,3-dioxolane-2-yl)phenyl}sulfonyl)- N,N -Synthesis of dimethylformamide

[0109]

[0110] In a three-necked flask (500 mL) equipped with a Dean-Stark apparatus S -[3-(dimethylcarbamoylsulfonyl)-5-formylphenyl] N,NDimethylcarbamothioate (10.1 g, 32.4 mmol), ethylene glycol (EG) (6.0 g, 97.2 mmol), and p-toluenesulfonic acid monohydrate (p-TsOH·H2O, 61.6 mg, 0.32 mmol) were mixed with toluene (80 mL). Cyclohexane (60 mL) was added to this mixture, and the mixture was heated to 140 °C under an argon atmosphere and stirred for 4 hours. After cooling the reaction mixture, it was extracted with ethyl acetate (EA) and washed several times with a saturated NaHCO3 solution and deionized water. The organic layer was dried with MgSO4, then the solvent was evaporated and vacuum dried to obtain 1-({3-[(dimethylcarbamoyl)sulfonyl]-5-(1,3-dioxolane-2-yl)phenyl}sulfonyl)- in the form of a pale yellow liquid. N,N 11.0 g of dimethylformamide was obtained (yield 95.3%).

[0111] 1 H and 13 1C NMR (CDCl3, ppm): δ H = 7.62-7.64 (t, 1H), 7.59-7.62 (d, 2H), 5.88 (s, 1H), 4.02-4.07 (m, 2H), 3.95-4.02 (m, 2H), 3.07 (brs, 6H), 3.01 (brs, 6H) δ C = 166.24, 142.56, 139.84, 134.14, 129.64, 102.60, 65.19, 37.03 (See Fig. 3)

[0113] 4) Synthesis of Sodium 5-(1,3-dioxolane-2-yl)benzene-1,3-disulfonate

[0114]

[0115] 1-({3-[(dimethylcarbamoyl)sulfonyl]-5-(1,3-dioxolane-2-yl)phenyl}sulfonyl)- in a single-neck flask (250 mL) N,NDimethylformamide (10.0 g, 30.9 mmol) and sodium hydroxide (NaOH) (3.1 g, 77.2 mmol) were mixed in anhydrous methanol (MeOH) (80 mL). The mixture was heated to 85 °C under an argon atmosphere and stirred for 6 hours. After the reaction, the mixture was cooled in an ice bath for 30 minutes, and hydrogen peroxide (H2O2, 42 g) was slowly added dropwise. The mixture was then returned to room temperature and stirred for 12 hours. After the reaction was complete, the solvent was evaporated, the residue was washed several times with ethyl acetate, and then vacuum dried to obtain 10.0 g of sodium 5-(1,3-dioxolane-2-yl)benzene-1,3-disulfonate in the form of a yellowish-white powder (yield 91.5%).

[0116] 1 H and 13 CN`R (D₂O, ppm): δ H = 8.18-8.24 (t, 1H), 8.02-8.07 (d, 2H), 5.98 (s, 1H), 4.15-4.23 (m, 2H), 4.07-4.15 (m, 2H) δ C = 143.96, 139.44, 126.41, 123.90, 101.79, 65.47 (See Fig. 4)

[0118] 5) Synthesis of Sodium 5-Formylbenzene-1,3-Disulfonate

[0119]

[0120] Sodium 5-(1,3-dioxolane-2-yl)benzene-1,3-disulfonate (10.0 g, 28.2 mmol), distilled water (8 mL), concentrated sulfuric acid (4.5 g, 45.9 mmol), and ethanol (EtOH) (80 mL) were mixed in a single-neck flask (250 mL). This mixture was heated at 90 °C under an argon atmosphere for 6 hours while stirring. Afterward, 50 mL of ethanol was added, and the product was filtered. The filtered solid was washed several times with ethyl acetate and vacuum dried to obtain the final product. As a result, 8.2 g of sodium 5-formylbenzene-1,3-disulfonate in the form of a pale yellow solid was obtained, with a yield of 93.1%.

[0121] 1 H and 13 1C NMR: δ H (DMSO-d6, ppm) = 10.05 (s, 1H), 8.15-8.22 (t, 1H), 8.05-8.10 (d, 2H) δ C (D₂O, ppm) = 193.90, 144.70, 137.07, 129.13, 128.29 (See Fig. 5)

[0123] 6) Synthesis of Sodium 5-Vinyl-1,3-Benzenedisulfonate

[0124]

[0125] Sodium 5-formylbenzene-1,3-disulfonate (3.8 g, 12.4 mmol), methyltriphenylphosphonium bromide (MTPPB, 5.1 g, 14.2 mmol), potassium carbonate (K2CO3, 2.6 g, 18.5 mmol), and anhydrous DMSO (23 mL) were added to a 1-neck flask (250 mL) and mixed under an argon atmosphere. The mixture was heated with stirring at 130 °C for 6 hours, then cooled to room temperature. The cooled reaction mixture was filtered and precipitated in 500 mL of dichloromethane (DCM). The precipitated solid was washed several times with ethyl acetate, and Soxhlet extraction was performed using acetone. Afterward, vacuum drying was performed to obtain 3.1 g of sodium 5-vinyl-1,3-benzenedisulfonate in the form of a white powder, with a yield of 79.5%.

[0126] 1 H and 13 1C NMR (based on sodium salt, DMSO-d6, ppm): δ H = 8.07-8.09 (t, 2H), 8.04-8.05 (d, 1H), 6.87-6.94 (q, 1H), 6.01-6.05 (d, 1H), 5.45-6.05 (d, 1H) δ C = 143.77, 139.59, 134.70, 125.69, 121.54, 117.57 (See Fig. 6)

[0128] 7) Ion-conductive polymer polystyrene-3,5-bisulfonic acid (PS di Synthesis of 35S)

[0129]

[0130] Polystyrene-3,5-bisulfonic acid (PS diTo synthesize 35S), 1.0 g (3.2 mmol) of sodium 5-vinyl-1,3-benzenedisulfonate, 60.4 mg (0.22 mmol) of 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (4-Cyano-4-(Phenylcarbonothioylthio)Pentanoic Acid (CPADB), 36.4 mg (0.13 mmol) of 4,4'-azobis(4-cyanovaleric acid) (4,4-Azobis(4-cyanovaleric acid); ACVA), and 6.0 mL of deionized water were placed in a 25 mL one-neck flask. After purging with argon gas for 30 minutes, reversible addition-cleavage chain transfer (RAFT) polymerization was carried out at 75 °C for 8 hours. The acid-form polymer was obtained by performing membrane dialysis with a mixed solution of methanol and water (1:1, v / v) for one week, followed by passing it through Amberlite IR-120 H acid-form ion exchange resin several times. After freeze-drying, 0.6 g of PS represented by Chemical Formula 4 below was obtained. di 35S was obtained, and the degree of polymerization was confirmed to be 12 via 1H NMR spectroscopy. (See Fig. 7)

[0131] [Chemical Formula 4]

[0132]

[0133] [Example 1]

[0134] 1) Preparation of ion-conducting polymer electrolyte membranes

[0135] PS prepared in the above manufacturing example di PS by substituting only one of the two functional groups -SO3H at 35S with -SO3Li di 35Li was manufactured. Manufactured PS di 35Li and ionic liquid [PYR 13 ][TFSI], LiTFSI salts 1 : 1 : 1 (PS di -SO3Li functional group of 35Li: [PYR 13An ionic liquid / salt / polymer solution was prepared by mixing in anhydrous DMSO at a molar ratio of ][TFSI] : LiTFSI salt. The prepared ionic liquid / salt / polymer solution was stirred at 40 °C for 12 hours and then freeze-dried at -20 °C for one week. A polymer electrolyte membrane was prepared by pressing the dried polymer electrolyte with a hot press.

[0136] 2) Electrode

[0137] The anode used lithium metal.

[0138] A slurry was prepared by mixing sulfur, conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) with NMP in a mass ratio of 60:30:10. The prepared slurry was coated onto a carbon-coated aluminum current collector using the doctor blade method (Loading density: approximately 2.0 mg / cm²). 2 ) and dried it in a vacuum oven at 60 ℃ and used it as the cathode.

[0139] 5 μL / cm² of 1,3-dioxolane (DOL) / 1,2-dimethoxyethane (DME) (1:1 vol%) was applied to the ion-conducting polymer electrolyte membrane prepared above. 2 CR2032 coin cells were fabricated in a glove box filled with argon gas by adding the following.

[0140] [Example 2]

[0141] In the preparation of the ion-conducting polymer electrolyte membrane of Example 1 above, the PS prepared in the preparation example above di By substituting both -SO3H functional groups at 35S with -SO3Na, PS di 35Na was manufactured, and the manufactured PS di 35Na and ionic liquid PMpipFSI, LiTFSI salts in a 1:1:1 ratio (PS diA battery cell was prepared in the same manner as in Example 1, except that an ionic liquid / salt / polymer solution was prepared by mixing in anhydrous DMSO in the molar ratio of -SO3Na functional group of 35Na : PMpipFSI : LiTFSI salt).

[0142] [Example 3]

[0143] In the preparation of the ion-conducting polymer electrolyte membrane of Example 1 above, the PS prepared in the preparation example above di A battery cell was prepared in the same manner as in Example 1, except that an ionic liquid / polymer solution was prepared by mixing 35S and the ionic liquid [HMIm][TFSI] in an anhydrous DMSO at a molar ratio of 1:0.5 (the -SO3H functional group of PSdi35S: [HMIm][TFSI]).

[0144] [Example 4]

[0145] In the preparation of the ion-conducting polymer electrolyte membrane of Example 1 above, the PS prepared in the preparation example above di A battery cell was prepared in the same manner as in Example 1, except that an ionic liquid / polymer solution was prepared by mixing 35S and the ionic liquid [HMIm][PF6] in an anhydrous DMSO at a molar ratio of 1:0.5 (the -SO3H functional group of PSdi35S: [HMIm][PF6]).

[0146] [Comparative Example 1]

[0147] 1) Preparation of ion-conducting polymer electrolyte membranes

[0148] Polystyrene-3,4-bisulfonic acid (PS) represented by Chemical Formula 5 below di By substituting only one of the two functional groups -SO3H of 34S with -SO3Li, PS di 34Li was manufactured. Manufactured PS di 34Li and ionic liquid [PYR 13 ][TFSI], LiTFSI salts 1 : 1 : 1 (PS di -SO3Li functional group of 34Li: [PYR13 An ionic liquid / salt / polymer solution was prepared by mixing in anhydrous DMSO at a molar ratio of ][TFSI] : LiTFSI salt. The prepared ionic liquid / salt / polymer solution was stirred at 40 °C for 12 hours and then freeze-dried at -20 °C for one week. A polymer electrolyte membrane was prepared by pressing the dried polymer electrolyte with a hot press.

[0149] [Chemical Formula 5]

[0150]

[0151] 2) Electrode

[0152] The anode used lithium metal.

[0153] A slurry was prepared by mixing sulfur, conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) with NMP in a mass ratio of 60:30:10. The prepared slurry was coated onto a carbon-coated aluminum current collector using the doctor blade method (Loading density: approximately 2.0 mg / cm²). 2 ) and dried it in a vacuum oven at 60 ℃ and used it as the cathode.

[0154] 5 μL / cm² of 1,3-dioxolane (DOL) / 1,2-dimethoxyethane (DME) (1:1 vol%) was applied to the ion-conducting polymer electrolyte membrane prepared above. 2 CR2032 coin cells were fabricated in a glove box filled with argon gas by adding the following.

[0155] [Comparative Example 2]

[0156] In the preparation of the ion-conducting polymer electrolyte membrane of Comparative Example 1 above, PS di By substituting both -SO3H functional groups of 34S with -SO3Na, PS di 34Na was manufactured, and the manufactured PS di34Na and ionic liquid PMpipFSI, LiTFSI salts in a 1:1:1 ratio (PS di A battery cell was prepared in the same manner as Comparative Example 1, except that an ionic liquid / salt / polymer solution was prepared by mixing in anhydrous DMSO in the molar ratio of -SO3Na functional group of 34Na : PMpipFSI : LiTFSI salt).

[0157] Comparison of ion-conducting polymers Degree of polymerization Number average molecular weight (kg / mol) Dispersion Example 1 (PS di 35Li) 12 3.45 1.04 Comparative Example 1 (PS di 34Li) 12 3.45 1.05

[0158] Comparison of ion-conducting polymer electrolyte membranes Glass transition temperature (°C) Ionic conductivity (23 ± 5 ℃) (mS / cm) Shear modulus (Pa) Example 1 15.1 0.71 2.3 x 10 5 Example 2 -3.6 0.78 1.6 x 10 3 Example 3 47.6 0.41 8.7 x 10 6 Example 4 -38.5 0.04 4.7 x 10 2 Comparative Example 1 -9.5 0.54 5.2 x 10 4 Comparative Example 2 -5.5 0.35 7.2 x 10 2

[0159] In Table 2 above, it was confirmed that the ionic conductivity and shear modulus of Example 1 showed superior values ​​compared to Comparative Example 1. This means that the ionic conductive polymer electrolyte membrane prepared from the ionic conductive polymer of the present invention can simultaneously achieve excellent ionic conductivity and appropriate mechanical properties by including a styrene derivative, in which an ionic functional group is introduced at a specific position of the benzene ring represented by Chemical Formula 1, as a repeating unit.

[0160] In Fig. 11, the ion conductivity measurement results confirmed that the ion-conducting polymer electrolyte membrane of Example 1 had higher conductivity over the entire temperature range compared to Comparative Example 1.

[0161] In Fig. 12, linear sweep voltammetry (LSV) measurement results confirmed that the ion-conducting polymer electrolyte membrane of Example 1 has wider electrochemical stability compared to Comparative Example 1.

[0162] In Fig. 13, it was confirmed that when the ion-conducting polymer electrolyte membrane of Example 1 is used, it has a higher capacity and lower polarization compared to Comparative Example 1.

[0163] As described above, the present invention has been explained by specific details and limited embodiments; however, this is provided merely to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above embodiments. Those skilled in the art can make various modifications and variations from this description.

[0164] Accordingly, the scope of the present invention is not limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

Claims

Claim 1 An ion-conducting polymer electrolyte membrane comprising: an ionic liquid; and an ion-conducting polymer polymer composed of repeating units represented by the following chemical formula 1. [Chemical Formula 1] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000. Claim 2 An ion-conducting polymer electrolyte membrane according to claim 1, wherein the ionic liquid is one or more mixtures selected from the group consisting of cationic liquids, anionic liquids, and neutral liquids. Claim 3 An ion-conducting polymer electrolyte membrane according to claim 1, wherein the ionic liquid comprises an ion pair selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Claim 4 An ion-conducting polymer electrolyte membrane according to claim 1, wherein the number average molecular weight of the ion-conducting polymer is 1,000 to 50,000 g / mol. Claim 5 An ion-conducting polymer electrolyte membrane according to claim 1, wherein the polydispersity index (PDI) of the ion-conducting polymer is 1.00 to 1.

20. Claim 6 In claim 1, the ion-conducting polymer 1 An ion-conducting polymer electrolyte membrane having a degree of polymerization (DP) of 2 to 200 as measured by H NMR spectroscopy. Claim 7 The ion-conducting polymer electrolyte membrane according to claim 1, wherein the ion-conducting polymer is composed of repeating units represented by the following chemical formula 2. [Chemical Formula 2] In the above chemical formula 2, R1 is -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000. Claim 8 In claim 1, the shear modulus of the ion-conducting polymer electrolyte membrane is 1.0 × 10⁻⁶ 2 Up to 1.0 × 10 8 Ion-conducting polymer electrolyte membrane that is Pa. Claim 9 In claim 1, the ion-conducting polymer electrolyte membrane has an ion conductivity of 1.0 × 10⁻⁶ at room temperature (23±5 ℃). -2 Ion-conducting polymer electrolyte membrane with a conductivity of mS / cm or higher. Claim 10 In claim 1, the glass transition temperature (T) of the ion-conductive polymer electrolyte membrane g ) is an ion-conducting polymer electrolyte membrane that is -50 to 100 ℃. Claim 11 A lithium-sulfur battery comprising an ion-conducting polymer electrolyte membrane selected from any one of claims 1 to 10. Claim 12 A method for manufacturing an ion-conducting polymer electrolyte membrane comprising: a step of preparing a mixed solution by mixing an ion-conducting polymer composed of repeating units represented by the following chemical formula 1 with an ionic liquid; a step of freeze-drying the mixed solution at -100 to -10 ℃ to remove the solvent and obtaining an ion-conducting polymer electrolyte; and a step of manufacturing an ion-conducting polymer electrolyte membrane by pressing or molding the ion-conducting polymer electrolyte. [Chemical Formula 1] In the above Chemical Formula 1, R1 and R2 are each independently -O(X 1 ), -SO3(X 2 ), -PO3(X 3 )2, -N(X 4 )2, -SO2N(X 5 )SO2CF3, -COO(X 6 ), -CN and It is a substituent selected from the group consisting of, where X 1 To X 7 Each is a monovalent cation independently selected from the group consisting of hydrogen, metal ions, ammonium ions, and organic cations. Also, n is 10 < n < 10,000. Claim 13 A method for manufacturing an ion-conducting polymer electrolyte membrane according to claim 12, wherein the ionic liquid is included in an equivalent ratio of 0.1 to 1:1 with the substituents of the polymer.

Images