Electrolyte membrane, fuel cell comprising same, and water electrolysis device and method for manufacturing same

Abstract

The present invention relates to an electrolyte membrane, a fuel cell comprising the same, and a water electrolysis device and a method for manufacturing the same. More specifically, the present invention relates to an electrolyte membrane comprising a polyfluorene-based ionomer having a fluorene backbone consisting of only carbon-carbon bonds and side chains consisting of perfluorinated sulfonic acid groups. The electrolyte membrane comprising the polyfluorene-based ionomer has high proton conductivity, excellent chemical durability, excellent mechanical properties, and excellent volume stability.

Description

Technical Field

[0001] This invention relates to an electrolyte membrane comprising a polyfluorene-based ionomer. More specifically, this invention relates to an electrolyte membrane containing a polyfluorene-based ionomer having a fluorene backbone consisting only of carbon-carbon bonds and side chains consisting of perfluorosulfonic acid groups. Electrolyte membranes containing polyfluorene-based ionomers exhibit high proton conductivity, excellent chemical durability, excellent mechanical properties, and excellent volume stability. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) includes a negative electrode, a positive electrode, and a polymer electrolyte membrane disposed between the negative and positive electrodes, and this structure is called a membrane electrode assembly.

[0003] Hydrogen is supplied as fuel to the positive electrode, and oxygen is supplied as an oxidant to the negative electrode. The hydrogen supplied to the positive electrode loses electrons and becomes a proton (H₂). + Electrons generated by hydrogen gas migrate to the negative electrode through the polymer electrolyte membrane. In this case, electrons do electrical work in the external circuit of the battery and migrate to the negative electrode. At the negative electrode, protons combine with oxygen and electrons to form water.

[0004] Here, the polymer electrolyte membrane is a cation exchange membrane that selectively transfers protons. The polymer electrolyte membrane should possess the following characteristics: 1) high ionic conductivity, 2) excellent physicochemical stability, 3) ease of scale-up, and 4) low production cost.

[0005] at present, It is a typical perfluorinated electrolyte membrane, and Gore These are perfluorinated porous filled membranes from WL Gore & Associates, Inc., both of which possess the advantages of high ionic conductivity and high chemical stability. However, these membranes suffer from the following problems: 1) decomposition due to oxygen free radicals; 2) environmental pollution during incineration due to hydrofluoric acid and other pollutants; and 3) high costs due to complex manufacturing processes. Therefore, it is difficult to apply these membranes to environmentally friendly, efficient, and low-cost energy conversion and storage systems.

[0006] As alternatives to the aforementioned membranes, various publications report the development of hydrocarbon-based ionomers and their applicability in various application areas. However, existing hydrocarbon cation exchange membranes (HC-CEMs) developed through polycondensation reactions exhibit low chemical stability due to the presence of heteroatoms with low binding energy in the polymer backbone. Furthermore, the low phase separation effect prevents the effective formation of ion transport channels, resulting in low ion conductivity. In addition to the above, poor physical stability is also a problem.

[0007] Materials are needed that can address the aforementioned problems of perfluorinated and hydrocarbon-based ionomers and meet the required properties of polymeric electrolyte membranes. Therefore, during the material development phase, polymer structures lacking chemically unstable bonds in the main polymer chain and capable of exhibiting fine phase separation in the regions of the polymer structure responsible for ion transport and physicochemical stability are desirable. Furthermore, methods for synthesizing these polymers relatively easily using inexpensive monomers are also desirable. Summary of the Invention

[0008] The present invention aims to solve the aforementioned problems related to the prior art.

[0009] In one aspect, the present invention provides an electrolyte membrane having high ionic conductivity and excellent chemical durability.

[0010] In another aspect, the present invention provides a method for manufacturing an electrolyte membrane that is advantageous for large-scale production.

[0011] The purpose of this invention is not limited to the above-described purpose, and other unmentioned purposes of this invention can be understood from the following description and will also be apparent from the embodiments of this invention.

[0012] The electrolyte membrane contains an ionomer represented by formula 1a or formula 1b.

[0013] [Equation 1a]

[0014]

[0015] [Equation 1b]

[0016]

[0017] In each of Formulas 1a and 1b, R1 comprises hydrogen or an alkyl group having a carbon number ranging from 1 to 3; R2 comprises hydrogen or an alkyl group having a carbon number ranging from 1 to 3; R3 comprises at least one of hydrogen, an unsubstituted alkyl group having a carbon number ranging from 1 to 3, and a halogen-substituted alkyl group having a carbon number ranging from 1 to 3; R4 comprises an alkylene group having a carbon number ranging from 1 to 7; R5 comprises at least one of an unsubstituted alkylene group having a carbon number ranging from 3 to 7, a halogen-substituted alkylene group having a carbon number ranging from 3 to 7, and an ether group in which a portion of the unsubstituted or substituted alkylene group has carbon atoms substituted with oxygen; and n is an integer in the range of 10 to 2,000.

[0018] The ionomer can be represented by the following formula 2.

[0019] [Equation 2]

[0020]

[0021] In Equation 2, n can be an integer in the range of 10-2,000.

[0022] This electrolyte membrane can be applied to fuel cells and / or water electrolysis devices.

[0023] The method for manufacturing the electrolyte membrane according to the present invention comprises preparing a first precursor of formula 3 by reacting a fluorene-based monomer with a hydrocarbon containing a halogen element having a carbon number range of 2-10 in the presence of an acid catalyst:

[0024] [Formula 3]

[0025]

[0026] (In Formula 3, R1 includes hydrogen or an alkyl group having 1-3 carbon atoms; R2 includes hydrogen or an alkyl group having 1-3 carbon atoms; R3 includes at least one of hydrogen, an unsubstituted alkyl group having 1-3 carbon atoms, and an alkyl group substituted with a halogen having 1-3 carbon atoms; R4 includes an alkylene group having 1-7 carbon atoms; X1 includes a halogen; and n is an integer in the range of 10-2,000).

[0027] The second precursor, represented by formula 4, is prepared by reacting the first precursor with a phenolic compound:

[0028] [Formula 4]

[0029]

[0030] (In Equation 4, R1, R2, R3 and R4 are the same as in Equation 3, X2 includes halogen elements, and n is an integer in the range of 10-2,000);

[0031] An ionomer of formula 1a is prepared by reacting a second precursor with a sulfonic acid-based compound; a polymer solution containing the ionomer and a solvent is prepared; and the polymer solution is applied to a substrate to manufacture an electrolyte membrane.

[0032] The acid catalyst may include at least one selected from the group consisting of aluminum chloride, trifluoromethanesulfonic acid (TFSA), hydrochloric acid, hydrofluoric acid, paratoluene acid, and combinations thereof.

[0033] The first precursor can be prepared by reacting at a temperature in the range of 5-25℃ for 1-2 hours.

[0034] The weight-average molecular weight of the first precursor can be in the range of 10,000 g / mol to 1,000,000 g / mol.

[0035] The weight-average molecular weight of the second precursor can be in the range of 10,000 g / mol to 1,500,000 g / mol.

[0036] Other aspects and preferred embodiments of the invention will be discussed below.

[0037] The above and other features of the invention will be discussed below. Attached Figure Description

[0038] The above and other features of the invention will now be described in detail with reference to certain exemplary embodiments of the invention illustrated in the accompanying drawings, which are given by way of example only and are not intended to limit the invention, wherein:

[0039] Figure 1 This is a photograph showing the electrolyte membrane according to the present invention;

[0040] Figure 2 It is a graph showing the evaluation results of the chemical durability of the electrolyte membrane according to the present invention;

[0041] Figure 3 It is a graph showing the evaluation results of the mechanical properties of the electrolyte membrane according to the present invention;

[0042] Figure 4 These are graphs showing the evaluation results of the volume stability of the electrolyte membrane according to the present invention; and

[0043] Figure 5 This is a graph showing the evaluation results of the ionic conductivity of the electrolyte membrane according to the present invention.

[0044] It should be understood that the accompanying drawings are not necessarily drawn to scale, and present slightly simplified illustrations of various preferred features illustrating the basic principles of the invention. Specific design features of the invention as disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, will be determined in part by the specific intended application and environment of use.

[0045] In the accompanying drawings, the reference numerals in several figures of the present invention refer to the same or equivalent parts. Detailed Implementation

[0046] Referring to the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more apparent from the following description of preferred embodiments. However, the invention is not limited to the embodiments disclosed herein and may be implemented in other forms. The embodiments disclosed herein are provided to make the invention thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

[0047] In describing each accompanying drawing, the same reference numerals refer to the same parts. In the drawings, the dimensions of the structures are shown at an enlarged scale for clarity of the invention. Although the terms "first," "second," etc., may be used herein to describe various parts, these parts should not be limited to these terms. These terms are used only for the purpose of distinguishing one part from another. For example, a first part may be referred to as a second part without departing from the scope of the invention, and similarly, a second part may be referred to as a first part. Unless the context clearly specifies otherwise, the singular form includes the plural form.

[0048] It should be understood that the terms "comprising," "including," and "having" specify the presence of the features, numbers, steps, operations, components, elements, or combinations thereof described herein, but do not preclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, elements, or combinations thereof. Furthermore, when a portion of a layer, membrane, region, plate, etc., is referred to as being "on top of" another portion, this includes not only the case where the portion is "directly on" the other portion, but also the case where other portions exist between the portion and the other portion. Conversely, when a portion of a layer, membrane, region, plate, etc., is referred to as being "below" another portion, this includes not only the case where the portion is "directly below" the other portion, but also the case where other portions exist between the portion and the other portion.

[0049] Unless otherwise specified, all figures, values, and / or expressions indicating the composition, reaction conditions, polymer composition, and quantities of the composite products used herein are approximations reflecting various measurement uncertainties, where various uncertainties arise when obtaining these values ​​in substantially different other things. Therefore, it should be understood that all figures, values, and / or expressions are modified by the term "about". Furthermore, when numerical ranges are disclosed herein, unless otherwise stated, the numerical range is continuous and includes all values ​​from the minimum to the maximum. Moreover, when a numerical range refers to integers, unless otherwise indicated, it includes all integers from the minimum to the maximum.

[0050] It should be understood that the terms "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles such as passenger cars, including SUVs, buses, trucks, various commercial vehicles, watercraft including various boats and ships, aircraft, etc., and include hybrid electric vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a gasoline-powered and an electric-powered vehicle.

[0051] The electrolyte membrane according to the invention comprises an ionomer represented by formula 1a or formula 1b.

[0052] [Equation 1a]

[0053]

[0054] [Equation 1b]

[0055]

[0056] In each of Formula 1a and Formula 1b, R1 comprises hydrogen or an alkyl group having a carbon number ranging from 1 to 3.

[0057] In addition, R2 includes hydrogen or an alkyl group having a carbon number range of 1-3.

[0058] In addition, R3 includes at least one of hydrogen, an unsubstituted alkyl group having a carbon number ranging from 1 to 3, and an alkyl group substituted with a halogen element having a carbon number ranging from 1 to 3.

[0059] In addition, R4 includes alkylene groups having a carbon number range of 1-7.

[0060] In addition, R5 includes at least one of the following: an unsubstituted alkylene group having 3-7 carbon atoms, a halogen-substituted alkylene group having 3-7 carbon atoms, and an ether group in which a portion of the unsubstituted or substituted alkylene group has carbon atoms substituted with oxygen.

[0061] In addition, n is an integer in the range of 10-2,000.

[0062] Recent studies have reported a problem where hydrocarbon-based ionomers with aryl ether bonds (Csp2-O) or low-energy bonds (benzyl CH bonds) decompose under the driving conditions of their application. The technical feature of the hydrocarbon-based ionomers according to the present invention is the absence of weak bonds in the main chain, and that they are polymers composed solely of carbon-carbon bonds. Therefore, the ionomers disclosed herein exhibit excellent chemical stability because the main chain is entirely composed of carbon-carbon bonds.

[0063] Furthermore, the invention is characterized by the design of the hydrocarbon-based ionomer as a branched polymer, which facilitates a fine hydrophilic / hydrophobic phase separation structure, and is formed by an alkyl structure with flexible long side chains. A cation exchange functional group, such as a perfluorosulfonic acid group, is introduced at the end of the hydrocarbon-based ionomer. Water / electrolytes, which play an important role in ion conduction in hydrocarbon-based ionomers, are mainly distributed around the ion exchange functional groups. According to the invention, the chain length of the side chains is controlled in various ways to prevent the interaction between water / electrolytes and the main chain. Furthermore, the invention is characterized by the introduction of perfluorosulfonic acid, which has excellent ion dissociation properties, into only a portion of the side chain ends, thereby simultaneously improving ion conduction behavior and physicochemical stability due to a significant hydrophilic / hydrophobic phase separation effect.

[0064] The hydrocarbon-based ionomers according to the present invention can be represented by the following formula 2.

[0065] [Equation 2]

[0066]

[0067] In Equation 2, n is an integer in the range of 10-2,000.

[0068] The method for manufacturing the electrolyte membrane according to the present invention comprises reacting a fluorene-based monomer with a hydrocarbon compound containing a halogen element and having a carbon number range of 2-10 in the presence of an acid catalyst to prepare a first precursor of formula 3:

[0069] [Formula 3]

[0070]

[0071] (In Formula 3, R1 comprises hydrogen or an alkyl group having 1-3 carbon atoms; R2 comprises hydrogen or an alkyl group having 1-3 carbon atoms; R3 comprises at least one of hydrogen, an unsubstituted alkyl group having 1-3 carbon atoms, and a halogen-substituted alkyl group having 1-3 carbon atoms; R4 comprises an alkylene group having 1-7 carbon atoms; X1 is a halogen; and n is an integer in the range of 10-2,000); The second precursor represented by Formula 4 is prepared by reacting the first precursor with a phenolic compound:

[0072] [Formula 4]

[0073]

[0074] (In Equation 4, R1, R2, R3 and R4 are the same as in Equation 3, X2 is a halogen, and n is an integer in the range of 10-2,000); the ionomer represented by Equation 1a is prepared by reacting the second precursor with a sulfonic acid-based compound; a polymer solution containing the ionomer and a solvent is prepared; and the polymer solution is applied to a substrate to manufacture an electrolyte membrane.

[0075] The manufacturing method according to the invention is characterized by mild manufacturing conditions and monomers suitable for large-scale production and industrialization. Hydrocarbon-based polymers used in existing cation exchange membranes can be obtained by high-temperature, long-term polycondensation in the presence of an alkaline catalyst. Meanwhile, the ionomers according to the invention can be obtained by polycondensation at room temperature in the presence of an acid catalyst for 1-2 hours. In this specification, "room temperature" refers to a temperature in the range of 0°C-40°C or 5°C-25°C.

[0076] The acid catalyst used to prepare the first precursor may include at least one selected from the group consisting of aluminum chloride, trifluoromethanesulfonic acid (TFSA), hydrochloric acid, hydrofluoric acid, p-methylbenzoic acid, and combinations thereof.

[0077] In addition, the first precursor can be obtained by reacting a fluorene-based monomer and a hydrocarbon compound at a temperature in the range of 5°C to 25°C for 1 to 2 hours.

[0078] Meanwhile, the weight-average molecular weight of the first precursor can be in the range of 10,000 g / mol to 1,000,000 g / mol. In addition, the weight-average molecular weight of the second precursor can be in the range of 10,000 g / mol to 1,500,000 g / mol.

[0079] The present invention will be described in more detail below based on embodiments, but the present invention is not limited to the following embodiments.

[0080] Preparation Examples - Preparation of Ionic Polymers

[0081] Ionic polymers are prepared according to the following reaction formula 1.

[0082] [Reaction Formula 1]

[0083]

[0084] (1) Preparation of the first precursor

[0085] 9,9-Dimethylfluorene (2 g, 10.40 mmol) and 7-bromo-1,1,1-trifluoroheptane-2-one (2.83 g, 11.44 mmol) were used as monomers. TFSA (9.2 g, 104.02 mmol) was used as an acid catalyst. Dichloromethane (DCM) was used as the reaction solvent at 26.5 wt% of the monomer weight. The monomers and catalyst were placed in the reaction solvent and reacted at approximately 5 °C for approximately 1 hour to synthesize the first precursor. After the reaction, the first precursor was precipitated in methanol (500 ml), washed several times with methanol, and dried in a vacuum oven at 50 °C.

[0086] (2) Preparation of the second precursor

[0087] The first precursor (2 g, 4.72 mmol) and 4-iodophenol (2.60 g, 11.81 mmol) were used as starting materials. Potassium carbonate (1.63 g, 11.81 mmol) was used as a catalyst. 8 wt% N,N-dimethylformamide (DMF) was used as the reaction solvent based on the weight of the starting materials. The starting materials and catalyst were placed in the reaction solvent and reacted at approximately 90 °C for approximately three hours to synthesize the second precursor. After the reaction, the second precursor was precipitated in a solution of methanol (1,000 ml) and hydrochloric acid (100 ml, 2 M), washed several times with distilled water, and dried in a vacuum oven at 50 °C.

[0088] In this case, the molecular weight of each of the first and second precursors was measured. Gel permeation chromatography was performed using tetrahydrofuran (THF) as the solvent and polystyrene as the standard. The results are shown in Table 1 below.

[0089] [Table 1]

[0090] entry Mn [g / mol] Mw[g / mol] PDI First Precursor 69,100 366,100 5.30 Second precursor 75,200 345,600 4.60

[0091] (3) Synthesis of ionomers

[0092] A second precursor (1 g, 1.78 mmol) and sodium 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-iodoethoxy)ethanesulfonate (ICF2CF2OCF2CF2SO3Na) (2.3 g, 5.33 mmol) were used as starting materials. Copper powder (1.13 g, 17.78 mmol) was used as a catalyst. 10 wt% N,N-dimethylacetamide (DMAc) was used as the reaction solvent based on the weight of the starting materials. The starting materials and catalyst were placed in the reaction solvent, and the temperatures were raised to 95 °C, 120 °C, and 165 °C, and the reaction was carried out for 3 h and 24 h, respectively, to synthesize the ionomer. After the reaction, the ionomer was filtered and centrifuged to remove the catalyst, and dried in a vacuum oven at 50 °C. Hereinafter, this ionomer is referred to as FL1C7ArF4. Furthermore, although the ionomer has been illustrated as a sodium salt in reaction formula 1, the electrolyte membrane is made of the ionomer, and the sodium is ionized when the electrolyte membrane contains water.

[0093] Example

[0094] A membrane was prepared by mixing 0.5 g of FL1C7ArF4 with 2.0 g of DMAc to form a solution, casting it onto a glass plate, and then drying it in a vacuum oven at 50 °C for 6 hours. The prepared membrane was separated from the glass plate using a water permeation method, placed in a desiccator, and dried to finally obtain an electrolyte membrane with a thickness of 20 μm. The results are as follows... Figure 1 As shown.

[0095] Experimental Example 1 - Evaluation of Chemical Durability

[0096] The chemical durability of the electrolyte membrane (FL1C7ArF4) according to the present invention was measured by the following method.

[0097] Fenton's reagent was prepared by dissolving 4 ppm ferrous(II) sulfate in a 3% hydrogen peroxide aqueous solution. The dried electrolyte membrane was cut into 1 cm × 1 cm pieces and placed in vials containing the Fenton's reagent. The vials were then placed in an oven at 80°C, and the state of the electrolyte membrane was observed every 10 minutes. τ1 represents the time when the membrane begins to decompose, while τ2 represents the time from complete decomposition to visual disappearance of the membrane.

[0098] As a comparative example, SPAES65 was used, which is a typical hydrocarbon ionomer represented by the following formula.

[0099]

[0100] The results are as follows Figure 2As shown in the figure. Referring to these results, when compared with comparative examples, the electrolyte membrane according to the invention exhibits three times or more of chemical durability at τ1 and twenty-three times or more of chemical durability at τ2. It has been demonstrated that, since the main chain consists only of carbon-carbon bonds, the electrolyte membrane according to the invention has superior chemical durability compared with comparative examples whose main chains are not composed solely of carbon-carbon bonds.

[0101] Experimental Example 2 - Evaluation of Mechanical Properties

[0102] The mechanical properties of the electrolyte membrane (FL1C7ArF4) according to the present invention were measured using a Lloyd LR-10K microscope, and specimens were prepared according to ASTM standard D638 (V-type specimen). Tensile strength was measured at a rate of 10 mm / min under conditions of 25°C and a relative humidity (RH) range of 20%–40%. In the mechanical property measurement experiments, at least five specimens were prepared and measured, and their average values ​​were calculated.

[0103] Nafion 212 (Sigma-Aldrich Co.) was used as a comparative example.

[0104] The results are as follows Figure 3 As shown in the figure. Referring to this result, it can be seen that the tensile strength of the electrolyte membrane according to the present invention is about 43.8 MPa, which is superior to that of the comparative example (30.1 MPa).

[0105] Experimental Example 3 - Evaluation of Volume Stability

[0106] The water absorption rate and dimensional change of the electrolyte membrane (FL1C7ArF4) according to the present invention were measured. The electrolyte membrane was dried in a desiccator and cut into 1cm × 4cm pieces, and the thickness and weight of the electrolyte membrane were measured. The electrolyte membrane was placed in a vial filled with distilled water and placed in a drying oven at 30°C. After 12 hours, the area, thickness, and weight of the swollen membrane were measured, and the dimensional change was measured using the following equation.

[0107] Water absorption rate (WU) [%] = [(W 湿 -W 干 ) / W 干 ]×100

[0108] Size change [%] = [((A)] 湿 ×T 湿 )-(A 干 ×T 干 )) / (A 干 ×T 干 )]×100

[0109] W 干and W 湿 These are the weights of the dry film and the swollen film, respectively. 干 and A 湿 These are the areas of the dry film and the swollen film, respectively, T 干 and T 湿 These are the thicknesses of the drying film and the swelling film, respectively.

[0110] Nafion 212 (Sigma-Aldrich Co.) was used as a comparative example.

[0111] The results are as follows Figure 4 As shown in Table 2.

[0112] [Table 2]

[0113]

[0114] refer to Figure 4 As can be seen from Table 2, the size variation of the electrolyte membrane according to the present invention is smaller.

[0115] Experimental Example 4 - Evaluation of Ion Conductivity

[0116] The proton conductivity of the electrolyte membrane (FL1C7ArF4) according to the present invention was measured. A 1×4 cm⁻¹ membrane was prepared. 2 Electrolyte membrane samples were prepared and combined with a four-probe cell, and then proton conductivity was measured using a BekkTech BT-552MX instrument.

[0117] Set the measurement conditions to a temperature and total humidity range of 80°C. Calculate the relative humidity using the ratio of the vapor pressure P(Td) at the water dew point to the saturated vapor pressure of the gas at 80°C, using the following equation.

[0118] RH (%) = P(Td) / P(Ts) × 100%

[0119] Before measurement, ionic conductivity was measured by maintaining temperature / humidity equilibrium for two hours at 80°C and 70% RH, and then decreasing the RH from 70% to 20% RH. Similarly, ionic conductivity was measured by increasing the RH from 20% to 100% RH. With the RH partially adjusted by 10%, resistance was measured at each 10% RH level, and conductivity was calculated using the equation for proton conductivity in the surface direction. Humidity equilibrium was maintained for 15 minutes under each humidity condition. The extracted ionic conductivity value (with decreased proton conductivity) was recorded at each humidity level.

[0120] Nafion 212 (Sigma-Aldrich Co.) was used as a comparative example.

[0121] The results are as follows Figure 5As shown in the figure. Referring to this result, it can be seen that the electrolyte membrane according to the present invention exhibits the same level of proton conductivity as the Nafion-based electrolyte membrane (typical electrolyte membrane).

[0122] According to the present invention, an electrolyte membrane with high ionic conductivity and excellent chemical durability can be obtained.

[0123] Furthermore, according to the present invention, the above-mentioned electrolyte membrane can be produced on a large scale using a simple method.

[0124] The effects of the present invention are not limited to those described above. It should be understood that the effects of the present invention include all effects that can be inferred from the above description.

[0125] Although embodiments of the invention have been described with reference to the accompanying drawings, those skilled in the art will understand that the invention can be implemented in other specific forms without departing from the technical spirit or essential features of the invention. Therefore, it should be understood that the above embodiments are not limiting in all respects, but rather illustrative.

Claims

1. An electrolyte membrane comprising an ionomer represented by formula 2: Formula 2 in, In Equation 2, n is an integer in the range of 10-2,000.

2. A fuel cell comprising the electrolyte membrane according to claim 1.

3. A water electrolysis device, comprising the electrolyte membrane according to claim 1.

4. A method for manufacturing an electrolyte membrane, comprising: The first precursor was prepared by reacting a fluorene-based monomer with 7-bromo-1,1,1-trifluoroheptane-2-one in the presence of an acid catalyst. The second precursor is prepared by reacting the first precursor with a phenolic compound; The ionomer represented by Formula 2 is prepared by reacting the second precursor with a sulfonic acid-based compound: Formula 2 In Equation 2, n is an integer in the range of 10-2,000; Prepare a polymer solution containing the ionomer and a solvent; and The polymer solution is applied to a substrate to create an electrolyte membrane.

5. The manufacturing method according to claim 4, wherein the acid catalyst comprises at least one selected from the group consisting of aluminum chloride, trifluoromethanesulfonic acid (TFSA), hydrochloric acid, hydrofluoric acid, and p-methylbenzoic acid.

6. The manufacturing method according to claim 4, wherein the first precursor is prepared by reacting at a temperature in the range of 5°C to 25°C for a period of 1 to 2 hours.

7. The manufacturing method according to claim 4, wherein the weight-average molecular weight of the first precursor is in the range of 10,000 g / mol to 1,000,000 g / mol.

8. The manufacturing method according to claim 4, wherein the weight-average molecular weight of the second precursor is in the range of 10,000 g / mol to 1,500,000 g / mol.

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