KR102098640B1 - Polymer electrolyte membrane, method for manufacturing the same and membrane-electrode assembly comprising the same - Google Patents

Abstract

The present invention relates to a polymer electrolyte membrane, a method for manufacturing the same, and a membrane-electrode assembly including the same, and provides a polymer electrolyte membrane including a porous support and a hydrocarbon-based ion conductor melt-impregnated inside the porous support.
The polymer electrolyte membrane improves the impregnation property of the hydrocarbon-based ion conductor to the porous support, thereby reducing the film thickness and improving process convenience, and the hydrocarbon-based ion conductor is uniformly and densely impregnated inside the porous support. Dimensional stability and ion conductivity are improved.

Description

Polymer electrolyte membrane, manufacturing method thereof, and membrane-electrode assembly including the same {POLYMER ELECTROLYTE MEMBRANE, METHOD FOR MANUFACTURING THE SAME AND MEMBRANE-ELECTRODE ASSEMBLY COMPRISING THE SAME}

The present invention relates to a polymer electrolyte membrane, a method for manufacturing the same, and a membrane-electrode assembly including the same, more specifically, to improve the impregnation property of the hydrocarbon-based ion conductor to the porous support, thereby reducing the film thickness and processing It relates to a polymer electrolyte membrane having improved dimensional stability and ion conductivity by improving the convenience and uniformly and densely impregnating the hydrocarbon-based ion conductor into the porous support, a method for manufacturing the same, and a membrane-electrode assembly including the same.

A fuel cell is a cell that directly converts chemical energy generated by oxidation of fuel into electrical energy, and has been spotlighted as a next-generation energy source due to its high energy efficiency and eco-friendly features with less pollutant emission.

Fuel cells generally have a structure in which an anode and a cathode are formed on both sides of an electrolyte membrane, and such a structure is called a membrane-electrode assembly (MEA).

Fuel cells can be classified into alkaline electrolyte fuel cells and polymer electrolyte fuel cells (PEMFC), depending on the type of electrolyte membrane. Among them, polymer electrolyte fuel cells have a low operating temperature of less than 100 ° C and quick start. Due to its advantages such as over-response characteristics and excellent durability, it has been spotlighted as a portable, vehicle, and home power supply.

A typical example of such a polymer electrolyte fuel cell is a hydrogen ion exchange membrane fuel cell (PEMFC) that uses hydrogen gas as fuel.

Summarizing the reactions occurring in the polymer electrolyte fuel cell, first, when fuel such as hydrogen gas is supplied to the anode, hydrogen ions (H +) and electrons (e-) are generated by the oxidation reaction of hydrogen in the anode. The generated hydrogen ion (H +) is transferred to the cathode through the polymer electrolyte membrane, and the generated electron (e-) is transmitted to the cathode through an external circuit. At the cathode, oxygen is supplied, and oxygen is combined with hydrogen ions (H +) and electrons (e-) to generate water by the reduction reaction of oxygen.

Since the polymer electrolyte membrane is a passage through which hydrogen ions (H +) generated in the anode are transferred to the cathode, the conductivity of the hydrogen ions (H +) should be excellent. In addition, the polymer electrolyte membrane must have excellent separation ability to separate hydrogen gas supplied to the anode and oxygen supplied to the cathode, and in addition, it must have excellent mechanical strength, dimensional stability, chemical resistance, and resistance loss at high current density ( It is required to have characteristics such as low ohmic loss.

As a polymer electrolyte membrane currently used, there is a perfluorosulfonic acid resin (hereinafter referred to as a fluorine-based ion conductor) as a fluorine-based resin. However, the fluorine-based ion conductor has a weak mechanical strength, and when used for a long time, pinholes are generated and thus energy conversion efficiency is deteriorated. There are attempts to increase the film thickness of the fluorine-based ion conductor in order to reinforce the mechanical strength, but in this case, there is a problem in that the resistance loss is increased and the use of expensive materials is increased, resulting in poor economic efficiency.

In order to improve the disadvantages of the fluorine-based ion conductor as described above, recently, hydrocarbon-based ion conductors have been actively developed. However, the polymer electrolyte membrane made of the hydrocarbon-based ion conductor has a disadvantage that the durability of the membrane is poor due to low dimensional stability and tensile strength.

To solve this problem, a polymer electrolyte membrane has been proposed in which the hydrocarbon-based ion conductor is impregnated into a porous support to improve mechanical strength. When the hydrocarbon-based ion conductor is prepared in the form of a reinforced film as described above, dimensional stability and tensile strength can be improved.

On the other hand, in order to prepare the hydrocarbon-based ion conductor in the form of a reinforced film, after dissolving the hydrocarbon-based ion conductor in a solvent to prepare an impregnation solution, the porous support is immersed in the impregnation solution for a certain period of time, or the impregnation is performed. A method of applying a solution to the surface of the porous support will be used. However, in the case of the method, in the process of evaporating and removing the solvent after the impregnation or application process, the affinity between the hydrocarbon-based ion conductor and the porous support decreases, and a cavity is generated inside the porous support, Cracks are generated on the surface of the porous support. For this reason, the impregnation or application process is repeated several times, and accordingly, the thickness of the polymer electrolyte membrane increases, and the thickness becomes non-uniform.

Accordingly, there is a great demand for a technology capable of improving impregnation property of the hydrocarbon-based ion conductor with respect to the porous support when manufacturing a reinforced film including a hydrocarbon-based ion conductor.

Korean Patent Publication No. 2006-0083374 (Publication Date: 2006.07.20) Korean Patent Publication No. 2006-0083372 (Publication date: 2006.07.20) Korean Patent Publication No. 2011-0120185 (Publication Date: 2011.11.03)

The object of the present invention is to improve the impregnation property of the hydrocarbon-based ion conductor to the porous support, thereby reducing the film thickness and improving process convenience, and the hydrocarbon-based ion conductor uniformly and densely impregnated inside the porous support. This is to provide a polymer electrolyte membrane having improved dimensional stability and ion conductivity.

Another object of the present invention is to provide a method for manufacturing the polymer electrolyte membrane.

Another object of the present invention is to provide a membrane-electrode assembly comprising the polymer electrolyte membrane.

The polymer electrolyte membrane according to an embodiment of the present invention includes a porous support, and a hydrocarbon-based ion conductor melt-impregnated inside the porous support.

The hydrocarbon-based ion conductor may have a glass transition temperature of 150 ° C to 200 ° C.

The hydrocarbon-based ion conductors include sulfonated polyimide, sulfonated polyaryl ether sulfone, sulfonated polyether ether ketone, sulfonated polybenzimidazole, sulfonated polysulfone, sulfonated polystyrene, sulfonated polyphosphazene, and combinations thereof It may be any one selected from the group consisting of.

The porous support is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof It may be any one selected from the group.

The polymer electrolyte membrane has hydrogen and / or oxygen gas at a rate of 20 mL / min on one side of the polymer electrolyte membrane cut to have an effective area of 50 cm ² and a thickness of 15 to 30 μm under a temperature of 80 ° C. and 50% relative humidity. When supplying, when argon or helium gas is supplied to the other surface of the polymer electrolyte membrane at the same rate, the concentration of hydrogen and / or oxygen detected by gas chromatography on the other surface of the polymer electrolyte membrane may be 20 barrer or less.

In addition, the polymer electrolyte membrane may have excellent dimensional stability. Specifically, the polymer electrolyte membrane may satisfy the condition of Equation 2 below.

[Equation 2]

12% ≥ (Twet-Tdry / Tdry) × 100 = △ T

In Equation 2, Twet is a thickness measured after immersing the polymer electrolyte membrane in distilled water at 80 ° C. for 24 hours, and then measuring the thickness after drying the same film for 24 hours at 80 ° C. under vacuum.

A method of manufacturing a polymer electrolyte membrane according to another embodiment of the present invention includes a step of melting and impregnating a hydrocarbon-based ion conductor with a porous support.

The manufacturing method of the polymer electrolyte membrane may include placing the hydrocarbon-based ion conductor on the surface of the porous support, and impregnating the porous support with molten hydrocarbon-based ion conductor by heating and melting the hydrocarbon-based ion conductor. You can.

The heating may be at a temperature of 150 to 250 ℃.

The hydrocarbon-based ion conductor may have a glass transition temperature of 150 to 200 ℃.

The hydrocarbon-based ion conductors include sulfonated polyimide, sulfonated polyaryl ether sulfone, sulfonated polyether ether ketone, sulfonated polybenzimidazole, sulfonated polysulfone, sulfonated polystyrene, sulfonated polyphosphazene, and combinations thereof It may be any one selected from the group consisting of.

The porous support is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof It may be any one selected from the group.

The porous support may be prepared by electrospinning.

The membrane-electrode assembly according to another embodiment of the present invention includes an anode electrode and a cathode electrode positioned opposite each other, and a polymer electrolyte membrane positioned between the anode electrode and the cathode electrode, wherein the polymer electrolyte membrane is a porous support, And a hydrocarbon-based ion conductor melt-impregnated inside the porous support.

The polymer electrolyte membrane of the present invention improves the impregnation property of the hydrocarbon-based ion conductor to the porous support, thereby reducing the film thickness and improving process convenience, and the hydrocarbon-based ion conductor uniformly and densely inside the porous support. Impregnation improves dimensional stability and ion conductivity.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

The polymer electrolyte membrane according to an embodiment of the present invention includes a porous support, and a hydrocarbon-based ion conductor melt-impregnated inside the porous support.

The polymer electrolyte membrane is a polymer electrolyte membrane in the form of a reinforced membrane filled with the hydrocarbon-based ion conductor on the porous support. The polymer electrolyte membrane is solidified after the hot-melted hydrocarbon-based ion conductor is impregnated inside the porous support. That is, after preparing the impregnation solution by dissolving the hydrocarbon-based ion conductor in a solvent as in the prior art, the impregnation solution is applied to the porous support, or the porous support is immersed in the impregnation solution for a period of time to obtain the hydrocarbon-based ion. The conductor is not impregnated inside the porous support. Accordingly, the polymer electrolyte membrane does not need to be removed by evaporating the solvent in a post-process, and there is no problem of cavities or cracks that may occur in the polymer electrolyte membrane when evaporating the solvent, thereby impregnating or There is no need to repeat the application several times, so the thickness of the polymer electrolyte membrane is thin and uniform.

The porous support consists of a collection of nanofibers that are irregularly and discontinuously connected in three dimensions, and thus includes a plurality of pores uniformly distributed. The porous support made of a plurality of pores uniformly distributed in this way has excellent porosity and properties (dimensional stability, etc.) that can complement the properties of the ion conductor.

The pore diameter, which is the diameter of the pores formed on the porous support, may be formed within the range of 0.05 to 30 μm. When the pore diameter is less than 0.05 μm, the ion conductivity of the polymer electrolyte may deteriorate, and the pore diameter is 30 μm. If exceeded, the mechanical strength of the polymer electrolyte may deteriorate.

In addition, porosity indicating the degree of pore formation in the porous support may be formed within a range of 50 to 98%. When the porosity of the porous support is less than 50%, the ionic conductivity of the polymer electrolyte may decrease, and when the porosity exceeds 98%, the mechanical strength and morphological stability of the polymer electrolyte may deteriorate.

The porosity (%) may be calculated by the ratio of the total volume of the porous support to the air volume, as shown in Equation 4 below.

[Equation 4]

Porosity (%) = (air volume / total volume) × 100

At this time, the total volume of the porous support is calculated by measuring the width, length, and thickness of a sample of a rectangular porous support, and the air volume of the porous support is calculated from the density after measuring the mass of the porous support sample. One polymer volume can be obtained by subtracting from the total volume of the porous support.

The porous support is composed of a collection of nanofibers that are irregularly and discontinuously connected in three dimensions, and an average diameter of the nanofibers may range from 0.005 to 5 μm. When the average diameter of the nanofibers is less than 0.005㎛, the mechanical strength of the porous support may be lowered, and when the average diameter of the nanofibers exceeds 5㎛, the porosity of the porous support may not be easily controlled.

The nanofiber is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof It may be any one selected from the group, but the present invention is not limited thereto.

The porous support may be formed to a thickness of 5 to 30㎛. When the thickness of the porous support is less than 5 μm, mechanical strength and morphological stability of the polymer electrolyte may deteriorate, and when the thickness of the porous support exceeds 30 μm, resistance loss of the polymer electrolyte may increase.

The polymer electrolyte membrane includes a hydrocarbon-based ion conductor impregnated into the porous support. The hydrocarbon-based ion conductor performs the ion-conducting function, which is a main function of the polymer electrolyte membrane, and the hydrocarbon-based ion conductor has excellent ion-conducting function and is advantageous in terms of price.

Meanwhile, the hydrocarbon-based ion conductor is solidified after being melt-impregnated inside the porous support. The hydrocarbon-based ion conductor may preferably use a glass transition temperature of 200 ° C or less. Melt impregnation of the hydrocarbon-based ion conductor is performed at 150 ° C or higher, and when the glass-ion temperature of the hydrocarbon-based ion conductor exceeds 200 ° C, melting of the hydrocarbon-based ion conductor may not occur. The glass transition temperature of the hydrocarbon-based ion conductor may be, for example, 150 ° C or higher. In this range, it is possible to provide a polymer electrolyte membrane exhibiting excellent mechanical strength and performance.

The hydrocarbon-based ion conductor may be preferably used as long as it has a glass transition temperature of 200 ° C. or less as described above. Specifically, sulfonated polyimide, sulfonated polyaryl ether sulfone, sulfonated polyether ether ketone, sulfonated poly Any one selected from the group consisting of benzimidazole, sulfonated polysulfone, sulfonated polystyrene, sulfonated polyphosphazene, and combinations thereof can be exemplified, and the sulfonated polyarylene ether series can be preferably used. .

Fuels separated by a polymer electrolyte membrane as a boundary due to the properties of the material of the polymer electrolyte membrane or binding or damage of the polymer electrolyte membrane may be mixed (crossover phenomenon). This crossover phenomenon is considered to be the main cause of deteriorating the performance of the fuel cell. Therefore, it can be said that the permeability of the polymer electrolyte membrane to fuel is a very important factor in determining the performance of the fuel cell.

The polymer electrolyte membrane may have very low fuel permeability by melting the ion conductor as well as the material of the ion conductor and impregnating the porous support. Since fuel in a fuel cell is hydrogen and oxygen gas, the fuel permeability may be referred to as gas permeability or gas permeability.

The polymer electrolyte membrane may have a gas permeability of 20 barrer or less under 50% relative humidity. Specifically, the gas permeability may be permeability of hydrogen, oxygen, or a mixture thereof, and may be measured under the following conditions.

Hydrogen and / or oxygen gas at a rate of 20 mL / min on one surface of the polymer electrolyte membrane cut to have an effective area of 50 to 100 cm ² and a thickness of 15 to 30 μm under a temperature of 60 to 80 ° C. and 50% relative humidity. , And argon or helium gas is supplied at the same rate to the other surface of the polymer electrolyte membrane. And, the gas permeability can be calculated by measuring the concentrations of hydrogen and / or oxygen by gas chromatography on the other side of the polymer electrolyte membrane. The effective area in the above refers to an area in contact with the gas so that the gas can permeate.

The gas permeability (Q, Barrer = 1x10 ^-10 cm ³ (STP) cm cm ^-2 cm ^-1 mmHg ^-1 ) can be obtained by Equation 1 below.

[Equation 1]

Gas permeability = B · l / A · t · Pwater · T

* T: Absolute temperature (K)

* A: Transmission area (cm ² )

* B: volume of hydrogen and / or oxygen passing through the electrolyte membrane (cm ³ )

* t: Processing time (sec)

* l: thickness of electrolyte membrane (cm)

* Pwater: Vapor pressure of water (cmHg)

The gas permeability has been tested under conditions similar to the actual operating environment of the fuel cell to show that it can provide a fuel cell with substantially superior performance.

The gas permeability measured under the above conditions may be, for example, less than 20 barrer, less than 15 barrer, less than 14 barrer, or less than 13 barrer. When the polymer electrolyte membrane has the gas permeability as described above, it is possible to provide a fuel cell with excellent performance. Ideally, it is preferable that no gas is passed through the polymer electrolyte membrane, so the lower limit of the gas permeability is not particularly limited and the lower limit may be 0.

The polymer electrolyte membrane may have excellent gas permeability even under more severe conditions than the above conditions. In one example, under a temperature of 80 ° C. and a relative humidity of 100%, hydrogen and / or oxygen gas is applied at a rate of 20 mL / min to one side of the polymer electrolyte membrane cut to have an effective area of 50 cm ² and a thickness of 15 to 30 μm. When supplied with argon or helium gas to the other side of the polymer electrolyte membrane at the same rate, the concentration of hydrogen and / or oxygen detected by gas chromatography on the other side of the polymer electrolyte membrane is 50 barrer or less, 40 barrer or less, 35 barrer Less than, 30 barrer or less, or 25 barrer or less.

In addition, the polymer electrolyte membrane may have excellent dimensional stability. Specifically, the polymer electrolyte membrane may satisfy the conditions of Equation 2 and / or Equation 3 below.

[Equation 2]

12% ≥ (Twet-Tdry / Tdry) × 100 = △ T

[Equation 3]

2% ≥ (Lwet-Ldry / Ldry) × 100 = △ L

In Equation 2, Twet is a thickness measured after immersing the polymer electrolyte membrane in distilled water at 80 ° C. for 24 hours, and then measuring the thickness after drying the same film for 24 hours at 80 ° C. under vacuum.

In Equation 3, Lwet is the area measured after immersing the polymer electrolyte membrane in distilled water at 80 ° C for 24 hours, and then taking out and measuring it. Ldry is the area measured after drying the same film at 80 ° C for 24 hours under vacuum.

A method of manufacturing a polymer electrolyte membrane according to another embodiment of the present invention includes a step of melting and impregnating a hydrocarbon-based ion conductor with a porous support.

More specifically, the method of manufacturing the polymer electrolyte membrane includes placing the hydrocarbon-based ion conductor on the surface of the porous support, and heating and melting the hydrocarbon-based ion conductor to impregnate the porous support with molten hydrocarbon-based ion conductor. It may include steps.

The polymer electrolyte membrane is a polymer electrolyte membrane in the form of a reinforced membrane impregnated with the hydrocarbon-based ion conductor on the porous support. The polymer electrolyte membrane is solidified after the hot-melted hydrocarbon-based ion conductor is impregnated inside the porous support. That is, after preparing the impregnation solution by dissolving the hydrocarbon-based ion conductor in a solvent as in the prior art, the impregnation solution is applied to the porous support, or the porous support is immersed in the impregnation solution for a period of time to obtain the hydrocarbon-based ion. The conductor is not impregnated inside the porous support. Accordingly, the polymer electrolyte membrane does not need to be removed by evaporating the solvent in a post-process, and there is no problem of cavities or cracks that may occur in the polymer electrolyte membrane when evaporating the solvent, thereby impregnating or There is no need to repeat the application several times, so the thickness of the polymer electrolyte membrane is thin and uniform.

First, the porous support is prepared by dissolving a precursor (precusor) in a spinning solvent to prepare a spinning solution, and spinning the prepared spinning solution to prepare a porous nanoweb composed of nanofibers having an average diameter of 0.005 to 5 μm, followed by preparation. It can be produced through a process of post-processing the nanoweb.

The porous support is preferably prepared through an electrospinning process to obtain high porosity and fine pores and thin films, but the present invention is not limited thereto.

The porous support is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof It can be produced by spinning any one selected from the group.

A detailed description will be given of a case in which a porous support is prepared using the polyimide. After the polyamic acid precursor is electrospinned to form a nanoweb precursor, the nanoweb precursor is imidized using a hot press to prepare a polyimide porous support.

More specifically, a precursor solution is prepared by dissolving a polyamic acid in a tetrahydrofuran (THF) solvent, and the spinning solution is sprayed with a temperature of 20 to 100 ° C. and a high voltage of 1 to 1,000 MPa. After discharging through to form a polyamic acid nanoweb on a collector, the polyamic acid nanoweb can be prepared by heat-treating the polyamic acid nanoweb in a hot press set at a temperature of 80 to 400 ° C to produce a porous polyimide support.

When preparing a polymer electrolyte membrane by impregnating the porous support with a hydrocarbon-based ion conductor, the mechanical properties of the polymer electrolyte can be improved compared to the polymer electrolyte membrane made of only the ion conductor, thereby reducing the film thickness, thereby minimizing the membrane resistance. To maximize performance. For example, in the case of a polymer electrolyte membrane (reinforced membrane) prepared by impregnating a support compared to a polymer electrolyte membrane (non-reinforced membrane) made of only an ion conductor of the same thickness, it is stable in moisture in a humid state due to a hydrophobic support. The rate of change is low and the tensile strength is high.

The hydrocarbon-based ion conductor is placed on the surface of the prepared porous support. The description of the hydrocarbon-based ion conductor is the same as that of the polymer electrolyte membrane according to the embodiment of the present invention, so a detailed description thereof will be omitted.

However, the hydrocarbon-based ion conductor may be preferably used having a glass transition temperature of 150 to 200 ℃. Melt impregnation of the hydrocarbon-based ion conductor is performed at 150 ° C or higher, and when the glass-ion temperature of the hydrocarbon-based ion conductor exceeds 200 ° C, melting of the hydrocarbon-based ion conductor may not occur.

The process of placing the hydrocarbon-based ion conductor on the surface of the porous support may use various methods known in the art, such as a laminating process, a spray process, a screen or rotary printing process, a gravure process.

Next, the hydrocarbon-based ion conductor is heated to melt.

The heating may be performed at a temperature of 150 to 250 ° C, preferably 150 to 200 ° C. The heating may be performed before or after the glass transition temperature of the hydrocarbon-based ion conductor, and when the heating temperature is less than 150 ° C., the hydrocarbon-based ion conductor may not be sufficiently dissolved and partially impregnated into the porous support, and the heating temperature may be When it exceeds 250 ° C, the ion-conducting functional group of the hydrocarbon-based ion conductor, typically a sulfonic acid group, can be decomposed.

The heating can be applied to any means that can transfer heat to the hydrocarbon-based ion conductor, and specifically, a heated roll or plate press is brought into contact with a laminate in which the hydrocarbon-based ion conductor is present on the surface of the porous support, or Alternatively, the laminate may be placed on a heating plate, and the entire laminate may be heated, but the present invention is not limited thereto.

The molten hydrocarbon-based ion conductor may be impregnated into the porous support without any special process. However, in order to improve the impregnation property of the molten hydrocarbon-based ion conductor, the melting and impregnation may be performed in a vacuum state. In addition, it is also possible to proceed by compressing the hydrocarbon-based ionic conductivity and the porous support with a roll or plate-shaped press for the same reason as described above.

The membrane-electrode assembly according to another embodiment of the present invention includes an anode electrode and a cathode electrode positioned opposite to each other, and the polymer electrolyte membrane positioned between the anode electrode and the cathode electrode. The polymer electrolyte membrane is the same as the polymer electrolyte membrane according to an embodiment of the present invention, where repeated descriptions are omitted.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[ Manufacturing example  A: Preparation of hydrocarbon-based ion conductors]

( Manufacturing example  One. Sulfonated Polyethersulfone - Ether ketone Random copolymer )

After installing a 4-neck round flask and Dean Stark Trap, 4,4'-biphenol (BP) and K ₂ CO ₃ were replaced with N-methyl-2-pyrrolidone ( NMP) and toluene, and the mixture was stirred with a mechanical stirrer and the temperature was gradually raised to 150 ° C over about 2 hours. At a temperature of 150 ° C, toluene was refluxed through the Dean Stark trap. After maintaining the reflux state for about 4 hours, toluene was removed. The dried SDCDPS (3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone), DCDPK (4,4'-Dichlorodiphenyl ketone) and biphenol were weighed in a glove box and put into a reactor with NMP. . The temperature was slowly raised to 195 ° C and stirred for 16 hours. After the polymerization was completed, precipitated in water, the salt was removed at 100 ° C. for 2 hours, filtered, and the resultant filtrate was dried to obtain a sulfonated polyether sulfone-ether ketone random copolymer.

( Manufacturing example  2. Sulfonated Polyethersulfone - Ether ketone Block copolymer )

After installing the four-necked round flask and Dean Stark trap, BP and K ₂ CO ₃ were added together with NMP and toluene and stirred with a mechanical stirrer, and the temperature was gradually raised to 150 ° C. over about 2 hours. Toluene was refluxed through a Dean Stark trap at a temperature of 150 ° C. After maintaining reflux for about 4 hours, toluene was removed. The dried SDCDPS (3,3'-Disulfonated-4,4'-dichlorodiphenyl sulfone) was weighed in a glove box and placed in a reactor with NMP. The temperature was slowly raised to 195 ° C and stirred for 16hr. After the polymerization was completed, the precipitate was precipitated in water to remove the salt for 2 hours at 100 ° C., filtered, and the resultant filtrate was dried to prepare a first polymer.

Next, a second polymer was prepared in the same manner as above, except that DCDPK (4,4'-Dichlorodiphenyl ketone) and biphenol were used in the same apparatus instead of SDCDPS.

The first and second polymers prepared above were put into a reactor together with NMP, the temperature was slowly raised to 150 ° C., stirred for 12 hrs, filtered, and the resulting filtrate was dried to sulfonate polyethersulfone-ether. A ketone block copolymer was obtained.

[ Manufacturing example  B: polymer Electrolyte membrane  Produce]

( Example  One)

The ion conductor solution prepared by dissolving 50 mol% of sulfonated polyarylene ethersulfone-etherketone (SPAESK) prepared in Preparation Example 1 in DMAc at 20 wt% was cast on a glass plate. After drying in a vacuum at 80 ° C. for 10 hours, a single membrane (non-reinforced film) was prepared, placed on both sides of the porous support, and then pressed and melted in a roll press at a temperature of 180 ° C. to impregnate the ion conductor with the polymer electrolyte membrane. It was prepared.

( Example  2)

The ion conductor solution prepared by dissolving 50 mol% of sulfonated polyarylene ethersulfone-etherketone (SPAESK) in DMAc at 20% by weight in DMAc was cast on a glass plate. After drying in a vacuum at 80 ° C. for 10 hours, a single membrane (non-reinforced film) was prepared, placed on both sides of the porous support, and then pressed and melted in a roll press at a temperature of 180 ° C. to impregnate the ion conductor with the polymer electrolyte membrane. It was prepared.

( Comparative example  One)

The porous support was added to the ion conductor solution prepared by dissolving 50 mol% of sulfonated polyarylene ethersulfone-etherketone (SPAESK) in DMAc at 20% by weight in DMAc. After impregnation for 30 minutes over a period of time, the mixture was left under reduced pressure for 1 hour, and dried under vacuum at 80 ° C. for 10 hours to prepare a polymer electrolyte membrane.

( Comparative example  2)

The porous support was impregnated in the ion conductor solution prepared by dissolving a perfluorinated sulfonic acid polymer (fluorine-based ion conductor) at 10% by weight in DMAc twice for 30 minutes, then left under reduced pressure for 1 hour and vacuumed at 80 ° C. The polymer electrolyte membrane was prepared by drying at 10 hours.

[ Experimental example : Polymer Electrolyte membrane  Measurement of properties]

The physical properties of the polymer electrolyte membranes prepared in Examples and Comparative Examples were measured, and the results are shown in Table 1 below.

Relative humidity (%) Comparative Example 1 Comparative Example 2 Example 1 Example 2 Ion conductivity (S / cm) ⁽¹⁾ 50 0.02 0.03 0.02 0.03 100 0.2 0.17 0.2 0.25 Water uptake (%) ⁽²⁾ 50 18 10 17 16 100 37 20 38 40 Hydrogen gas permeability ⁽³⁾
(Barrer) 50 15 90 13 10 100 35 120 23 25 Cell performance ⁽⁴⁾
(A / cm ² at 0.6V) 50 0.5 0.7 0.7 0.8 100 0.9 One One 1.2 Swelling ratio (%) ⁽⁵⁾ Thickness swelling ratio 15 20 8 5 Area swelling ratio 2 5 2 One

(1) Ion conductivity: After cutting the polymer electrolyte membrane prepared in Examples or Comparative Examples to 1 X 3 cm, it was mounted on a measuring cell with a conductivity platinum electrode. Impedance device (model name: Solartron 1287 + 1255B) connected to a measuring device (model name: MSB-AD-V-FC, manufacturer: Bell Japan) at 80 ° C, which is similar to the actual operating conditions, changing the relative humidity from 10% to 100%. Manufacturer: Lloyd Instruments) to measure the film resistance to evaluate the ion conductivity.

(2) Water uptake: 50 mg of the polymer electrolyte membrane prepared in Examples or Comparative Examples was mounted on a sample holder of a magnetic suspension balance (MSB). And at 80 ℃, which is similar to the actual operating conditions, the relative humidity is changed from 10% to 100%, and the measurement device (model name: MSB-AD-V-FC, manufacturer: Bell Japan) causes the moisture content due to the relative humidity of the sample. Water uptake was calculated from the following equation by measuring the weight change.

Water uptake (%) = (Wwet-Wdry / Wdry) × 100

(3) Permeability of hydrogen or oxygen gas: The polymer electrolyte membrane prepared in Examples or Comparative Examples was cut to have an effective area of 50 cm ² and a thickness of 25 μm. Subsequently, the cut polymer electrolyte membrane was mounted on a gas permeable cell, and gas permeability was measured using a measuring device (model name: Membrane test station, manufacturer: ETIS).

For measurement of gas permeability, hydrogen or oxygen gas is supplied at a rate of 20 ml / min using argon or helium gas as a carrier gas at one side of the polymer electrolyte membrane at a temperature of 80 ° C. and a relative humidity of 50% to 100%, and the polymer electrolyte Argon or helium gas was supplied at the same speed to the other side of the membrane. Then, the hydrogen or oxygen gas flowing out to the other surface of the polymer electrolyte membrane supplied with hydrogen or oxygen gas is analyzed by gas chromatography (model name: SHIMADZU GC-14B, manufacturer: SHIMADZU) to determine the gas permeation amount of the polymer electrolyte membrane in the actual operating environment. It was measured.

The gas permeability (Q, Barrer = 1x10 ^-10 cm ³ (STP) cm cm ^-2 cm ^-1 mmHg ^-1 ) is obtained by Equation 1 below.

[Equation 1]

Gas permeability = B · l / A · t · Pwater · T

* T: Absolute temperature (K)

* A: Transmission area (cm ² )

* B: volume of hydrogen and / or oxygen passing through the electrolyte membrane (cm ³ )

* t: Processing time (sec)

* l: thickness of electrolyte membrane (cm)

* Pwater: Vapor pressure of water (cmHg)

(4) Cell performance: A membrane-electrode assembly was prepared by forming an electrode layer using a decal method on a polymer electrolyte membrane prepared in Examples or Comparative Examples. At this time, the catalyst layer of the electrode is coated on a release film with a composition for forming a catalyst layer containing a Pt / carbon catalyst and dried to form a catalyst layer, so that the release layer coated with the catalyst layer faces the catalyst layer and the reinforced composite film on both sides of the reinforced composite film. After positioning, the catalyst layer was transferred to both sides of the reinforced composite film by hot pressing at a pressure of 100 to 200 kg / cm ² and a temperature of 120 ° C. Subsequently, a membrane-electrode assembly (MEA) was prepared by fastening a gas fiddusion layer (GDL) on both sides of the reinforced composite membrane bonded with the catalyst layer. At this time, the loading amount of the catalyst was 0.4 mg / cm ² .

The fabricated MEA was concluded as a unit cell with GDL. Mounted the unit cell to the evaluation device (model name: PEMFC test station, manufacturer: CNL) and humidified by setting the temperature to 80 ℃, relative humidity to 50% or 100%, and hydrogen to the Anode and Cathode. Air was supplied by setting a flow rate according to a stoichiometric ratio of 1.2: 2.0. Then, after circulating the voltage and activating it in an appropriate cycle according to MEA, cell performance was measured by drawing a polarization curve (IV curve) according to the voltage and current density.

(5) Swelling ratio: The polymer electrolyte membrane prepared in Examples or Comparative Examples was immersed in distilled water at 80 ° C. for 24 hours. Then, the polymer electrolyte membrane was taken out from distilled water, and the thickness and area of the wet polymer electrolyte membrane were measured. Then, the polymer electrolyte membrane was dried in a vacuum at 80 ° C. for 24 hours, and then thickness and area were measured. The swelling ratio with respect to the thickness and the swelling ratio with respect to the thickness by substituting the thicknesses (Twet) and the area (Lwet) of the polymer electrolyte membrane and the thicknesses of the dry state (Tdry) and the area (Ldry) into Equations 2 and 3 below. Was measured.

[Equation 2]

(Twet-Tdry / Tdry) × 100 = △ T (swelling ratio to thickness,%)

[Equation 3]

(Lwet-Ldry / Ldry) × 100 = △ L (swelling ratio to area,%)

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (13)

A polymer electrolyte membrane comprising a porous support and a hydrocarbon-based ion conductor melt-impregnated inside the porous support,
The hydrocarbon-based ion conductor is a sulfonated polyether sulfone-ether ketone random copolymer or a sulfonated polyether sulfone-ether ketone block copolymer,
The polymer electrolyte membrane is (i) a first hydrogen gas permeability of 10 to 13 barrer at a temperature of 80 ° C and a relative humidity of 50%, and (ii) a second of 23 to 25 barrer at a temperature of 80 ° C and a relative humidity of 100%. Hydrogen gas permeability, and (iii) has a thickness swelling ratio of 5% to 8% when immersed in distilled water at 80 ° C. for 24 hours and then dried in a vacuum at 80 ° C. for 24 hours-the thickness swelling ratio is as follows. Calculated by equation-,
△ T (%) = [(Twet-Tdry) / Tdry] × 100
(Wherein, △ T is the thickness swelling ratio, Twet is the thickness of the polymer electrolyte membrane in a wet state measured immediately after immersion for 24 hours, Tdry is the thickness of the polymer electrolyte membrane in a dry state measured immediately after drying for 24 hours)
Each of the first and second hydrogen gas permeabilities is 50 cm ² and an argon or helium gas at a rate of 20 mL / min, respectively, and hydrogen gas on one surface of the polymer electrolyte membrane cut to have an effective area of 25 μm and a thickness of 25 μm. Obtained by measuring the concentration of hydrogen detected by gas chromatography on the other side when supplied,
Polymer electrolyte membrane. According to claim 1,
The hydrocarbon-based ion conductor is a polymer electrolyte membrane having a glass transition temperature of 150 to 200 ℃. According to claim 1,
The polymer electrolyte membrane has an area swelling ratio of 1% to 2% when immersed in distilled water at 80 ° C for 24 hours and then dried in a vacuum at 80 ° C for 24 hours-the area swelling ratio is calculated by the following equation. Calculated-,
△ L (%) = [(Lwet-Ldry) / Ldry] × 100
(Wherein, ΔL is the area swelling ratio, Lwet is the area of the polymer electrolyte membrane in a wet state measured immediately after immersion for 24 hours, Ldry is the area of the polymer electrolyte membrane in a dry state measured immediately after drying for 24 hours)
Polymer electrolyte membrane. According to claim 1,
The porous support is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof A polymer electrolyte membrane that is any one selected from the group. delete Placing a hydrocarbon-based ion conductor on the surface of the porous support; And
Heating and melting the hydrocarbon-based ion conductor to impregnate the porous support with molten hydrocarbon-based ion conductor.
Including,
The hydrocarbon-based ion conductor is a sulfonated polyether sulfone-ether ketone random copolymer or a sulfonated polyether sulfone-ether ketone block copolymer,
Method for manufacturing polymer electrolyte membrane. delete The method of claim 6,
The heating is a method of manufacturing a polymer electrolyte membrane consisting of a temperature of 150 to 250 ℃. The method of claim 6,
The hydrocarbon-based ion conductor is a method of manufacturing a polymer electrolyte membrane having a glass transition temperature of 150 to 200 ℃. delete The method of claim 6,
The porous support is made of nylon, polyimide, polybenzoxazole, polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene, polyarylene ether sulfone, polyether ether ketone, copolymers thereof, and combinations thereof Method for producing a polymer electrolyte membrane that is any one selected from the group. The method of claim 6,
The porous support is a method for producing a polymer electrolyte membrane that is produced by electrospinning. An anode electrode and a cathode electrode positioned to face each other, and
A membrane-electrode assembly comprising the polymer electrolyte membrane of claim 1 positioned between the anode electrode and the cathode electrode.