KR20110120185A - Polymer electrolyte membrane for fuel cell and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A polymer electrolyte membrane for a fuel cell is provided to decrease ohmic loss, to reduce costs for materials, to improve heat resistance of a membrane and to lower the heat expansion rate of the membrane. CONSTITUTION: A polymer electrolyte membrane comprises: a porous nanoweb which has a melting point of 300 deg.C or higher, and is insoluble in an organic solvent such as NMP, DMF, DMA or DMSO at room temperature; and ion conductors which fill the interiors of the pores of the porous nanoweb and contain hydrocarbon-based materials soluble in the organic solvent at room temperature.

Description

Polymer Electrolyte Membrane for Fuel Cell and Method for Manufacturing the Same

The present invention relates to an electrolyte membrane used for a fuel cell, and more particularly to a polymer electrolyte membrane.

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

A fuel cell generally has 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) according to the type of electrolyte membrane. Among them, polymer electrolyte fuel cells have a low operating temperature of less than 100 ° C. and fast start-up. Due to the advantages of over response characteristics and excellent durability, it has been spotlighted as a portable, vehicle, and home power supply.

Representative examples of such a polymer electrolyte fuel cell may include a hydrogen ion exchange membrane fuel cell (PEMFC) using hydrogen gas as a fuel.

Summarizing the reaction occurring in the polymer electrolyte fuel cell, first, when a fuel such as hydrogen gas is supplied to the anode, hydrogen ions (H ⁺ ) and electrons (e ⁻ ) are generated by the oxidation of hydrogen at the anode. The generated hydrogen ions (H ⁺ ) are transferred to the reduction electrode through the polymer electrolyte membrane, and the generated electrons (e ⁻ ) are transferred to the reduction electrode through an external circuit. Oxygen is supplied from the reduction electrode, and oxygen is combined with hydrogen ions (H ⁺ ) and electrons (e ⁻ ) to generate water by reduction of oxygen.

Since the polymer electrolyte membrane is a passage through which hydrogen ions (H ⁺ ) generated from 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 also have excellent mechanical strength, dimensional stability, chemical resistance, and the like. Ohmic loss) should be small.

The polymer electrolyte membrane currently used is a fluororesin, a perfluorosulfonic acid resin (hereinafter referred to as a fluorine-based ion conductor). However, fluorine-based ion conductors have a weak mechanical strength, so that when used for a long time, pinholes are generated, thereby lowering energy conversion efficiency. In order to reinforce the mechanical strength, attempts have been made to increase the thickness of the fluorine-based ion conductor, but in this case, the resistance loss is increased, and the use of expensive materials is increased, thereby reducing the economic efficiency.

In order to solve such a problem, a polymer electrolyte membrane having improved mechanical strength by impregnating a liquid fluorine ion conductor in a porous polytetrafluoroethylene resin (trade name: Teflon) (hereinafter referred to as' teflon resin), which is a fluorine resin, It has been proposed. In this case, the hydrogen ion conductivity may be slightly lower than that of the polymer electrolyte membrane composed of the fluorine-based ion conductor alone, but the mechanical strength is relatively excellent, and thus the thickness of the electrolyte membrane can be reduced, thereby reducing the loss of resistance.

However, since Teflon resin has very low adhesiveness, the ion conductor selection is limited, and a product having a fluorine-based ion conductor has a disadvantage in that a fuel crossover phenomenon is larger than that of a hydrocarbon system. In addition, since the price of not only the fluorine-based ion conductor but also the porous Teflon resin is expensive, it is required to develop new materials which are still inexpensive for mass production.

In order to solve the above problems, the present invention has a high melting point, insoluble in organic solvents and excellent porosity of the nano-web filled with ion conductors under optimum conditions, the overall thickness can be reduced, the resistance loss The purpose of the present invention is to provide a polymer electrolyte membrane having the effect of reducing the material cost, reducing the heat resistance and lowering the thickness expansion rate, so that the ion conductivity does not decrease for a long time.

As one aspect for achieving the above object, the present invention, a porous nano web having a melting point of 300 ℃ or more, insoluble in organic solvents of NMP, DMF, DMA, or DMSO at room temperature; And an ion conductor filled in the pores of the porous nanoweb and comprising a hydrocarbon-based material soluble in the organic solvent at room temperature.

As another aspect for achieving the above object, the present invention is a process for preparing a spinning solution by melting a precursor (precusor) in a spinning solvent; Electrospinning the spinning solution to prepare a porous nanoweb made of nanofibers having an average diameter of 0.005 to 5 μm; Post-processing the porous nanoweb such that the porous nanoweb is insoluble in an organic solvent of NMP, DMF, DMA, or DMSO; Preparing an ion conductor solution by dissolving an ion conductor including a hydrocarbon-based material soluble in the organic solvent in the organic solvent; And removing the organic solvent after filling the ion conductor solution in the pores of the post-processed porous nanoweb such that the thickness ratio of the nanoweb measured by the following equation is 20% or more. An electrolyte membrane is provided.

Thickness ratio of nano web = [A / (B + C)] × 100

A is the average thickness of the nanoweb, B is the average thickness of the upper ion conductor, and C is the average thickness of the lower ion conductor.

The present invention has the following effects.

First, since the polymer electrolyte membrane according to the present invention is a structure in which the ion conductor is filled in the pores of the nanoweb which are excellent in heat resistance and insoluble in organic solvents under optimum conditions, the overall thickness of the electrolyte membrane can be reduced, thereby improving ion conductivity and resistance. The loss is reduced, and the thickness expansion ratio can be lowered, thereby maintaining the performance for a long time.

Second, since the polymer electrolyte membrane according to the present invention is composed of both a hydrocarbon-based polymer material and the nanoweb and the ion conductor, there is an excellent effect of adhesion between both excellent durability.

Third, since the polymer electrolyte membrane according to the present invention uses a relatively inexpensive hydrocarbon-based polymer material without using an expensive fluorine-based ion conductor or Teflon resin as in the prior art, it is excellent in economical efficiency in mass production.

1 is a cross-sectional view of a polymer electrolyte membrane according to an embodiment of the present invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

Hereinafter, the present invention will be described in detail.

The polymer electrolyte membrane according to the present invention includes a porous nanoweb, and an ion conductor filled in pores of the porous nanoweb.

The porous nanoweb serves to enhance the mechanical strength of the polymer electrolyte membrane and to promote morphological stability by inhibiting volume expansion by moisture. In addition, the porous nanoweb is made of a hydrocarbon-based polymer which is advantageous in terms of price.

In particular, since the porous nanoweb is insoluble in the organic solvent of NMP, DMF, DMA, or DMSO at room temperature, the process of filling the ion conductor in the nanoweb pores is easy. That is, in order to fill the ion conductor in the pores of the nanoweb, the ion conductor is dissolved in an organic solvent to prepare an ion conductor solution, and then the ion conductor solution is filled in the pores of the porous nanoweb, and the porous nanoweb is dissolved in the organic solvent. In this case, during the process of filling the ion conductor solution into the pores of the porous nanoweb, the nanoweb is dissolved to obtain a polymer electrolyte membrane having a desired structure. Thus, the porous nanoweb comprises a hydrocarbon-based material that is insoluble in organic solvents.

The porous nanoweb includes a hydrocarbon-based material having a melting point of 300 ° C. or higher. As such, since the porous nanoweb has a high melting point, the porous nanoweb maintains a stable shape even in a high temperature environment and is not easily separated from the electrode.

Examples of the porous nanoweb that satisfies all of the above required characteristics include polyimide, polybenzoxazole, copolymers thereof, or mixtures thereof.

The porous nanoweb consists of a three-dimensionally connected web consisting of a predetermined fiber, in this case the thickness of the fiber may be in the range of 0.005 to 5 ㎛. If the thickness of the fibers constituting the nano-web is less than 0.005 ㎛ may decrease the mechanical strength of the porous nano-web, and if the thickness of the fiber exceeds 5 ㎛ may not be easy to control the porosity of the porous nano-web.

The porous nanoweb may be formed to a thickness of 5 to 20 ㎛. When the thickness of the porous nanoweb is less than 5 μm, the mechanical strength and shape stability of the polymer electrolyte membrane may be reduced, and when the thickness of the porous nanoweb exceeds 20 μm, the resistance loss of the polymer electrolyte membrane may increase.

The porous nanoweb may have a porosity of 70 to 98%. When the porosity of the porous nanoweb is less than 70%, the ionic conductivity of the polymer electrolyte membrane may drop, and when the porosity of the porous nanoweb exceeds 98%, the mechanical strength and shape stability of the polymer electrolyte membrane may decrease.

The ion conductor performs an ion conducting function, which is a main function of the polymer electrolyte membrane, and can use a hydrocarbon-based polymer having such an ion conducting function and advantageous in terms of price, and as described above, the pores of the porous nanoweb. In order to facilitate the process of filling the ion conductor therein, a hydrocarbon-based material soluble in an organic solvent is included. Hydrocarbon-based polymers that can satisfy all of these requirements can be used in ionic conductors such as sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (S-PEEK), and sulfonate polybenzimidazole (sulfonated polybenzimidazole: S-PBI), sulfonated polysulfone (S-PSU), sulfonated polystyrene (S-PS), sulfonated polyphosphazene, or mixtures thereof. However, the present invention is not limited thereto. Here, "soluble" with respect to the organic solvent means a characteristic that is dissolved in the organic solvent of NMP, DMF, DMA, or DMSO at room temperature.

The ion conductor is filled in the pores of the porous nanoweb, the adhesion between the ion conductor and the porous nanoweb may be degraded when the operating conditions such as temperature or humidity during fuel cell operation is changed, in the case of the present invention Since both the ion conductor and the porous nanoweb are composed of hydrocarbon-based polymers, the adhesion between the two is basically excellent. In addition, the hydrocarbon-based material included in the ion conductor and the hydrocarbon-based material included in the porous nanoweb may be composed of the same material system. Specifically, S-PI (sulfonated polyimide) is used as the ion conductor and as the porous nanoweb. If polyimide is used, the adhesion between the ion conductor and the porous nanoweb may be very excellent.

As described above, as the adhesion between the porous nanoweb and the ion conductor is excellent, the electrolyte membrane including these can inhibit expansion in three dimensions by moisture, so that the length and thickness expansion ratio are relatively low.

As described above, the polymer electrolyte membrane including the porous nanoweb having excellent pore properties and the ion conductor sufficiently filled in the pores of the porous nanoweb has a thickness expansion ratio of 10% or less. That is, it may be preferable that the thickness expansion ratio of the degree of deformation in the thickness direction with respect to the moisture of the polymer electrolyte membrane is 10% or less. The polymer electrolyte membrane may be used in a fuel cell separator, and the separator repeats expansion and contraction as it is exposed to high humidity. If the thickness expansion ratio of the separator is too high, the separator may be separated from the electrode. If so, the performance of the fuel cell may be drastically reduced.

The thickness expansion ratio of the polymer electrolyte membrane is measured from the following equation.

Thickness Expansion Rate (%) = [(T1-T0) / T0)] × 100

In this case, T0 is the average thickness of the polymer electrolyte membrane before expansion in water, T1 is the average thickness of the polymer electrolyte membrane after expansion in water.

This thickness expansion ratio is most affected by the material of construction, but also greatly affected by the shape of the electrolyte membrane. For example, when the electrolyte membrane is a single membrane composed of only ion conductors, the membrane has a very high moisture content due to the ion conductor characteristics, and due to this characteristic, the single membrane is directly affected by moisture, and thus the thickness expansion ratio may be very large.

In addition, the electrolyte membrane in which the ion conductor is filled in the web formed by entangled fibers in three dimensions can suppress expansion in three dimensions by moisture, so that the length and thickness expansion ratio are relatively low. In particular, when the web serving as the support and the ion conductor are strongly attached, the thickness expansion ratio of the electrolyte membrane is further lowered. Because the web serving as the support is usually hydrophobic, the expansion does not occur easily due to moisture, and the ion-conductor strongly attached to the web is affected by the water expansion characteristics of the web, thereby lowering the thickness expansion rate.

In addition, when the web is composed of fibers having a small diameter, the surface area, porosity, and orientation can have an optimal three-dimensional structure, and thus the electrolyte membrane prepared therefrom has a lower thickness expansion ratio.

The polymer electrolyte membrane of the present invention uses a nanoweb having excellent surface area and porosity, which is prepared by laminating nanofibers under optimum conditions, and has a low thickness expansion rate of 10% or less because it consists of such nanoweb and strongly adhered ion conductors. Will have

The polymer electrolyte membrane may have a thickness ratio of 20% or more as measured by the following formula.

Thickness ratio of nano web = [A / (B + C)] × 100

A is the average thickness of the nanoweb, B is the average thickness of the upper ion conductor, and C is the average thickness of the lower ion conductor.

If the thickness ratio of the nanoweb is less than 20%, as the support portion of the electrolyte membrane is too low, the mechanical properties may be drastically lowered, so durability may be greatly reduced, and battery performance decreases as the thickness expansion ratio is increased. Because it can be.

Since the polymer electrolyte membrane according to the present invention has a structure in which the ion conductor is filled in the pores of the porous nanoweb, the mechanical strength is excellent to 10 MPa or more. In addition, as the mechanical strength is improved, the overall thickness of the polymer electrolyte membrane can be reduced to 80 μm or less, thereby increasing the ion conduction speed, reducing the resistance loss, and reducing the material cost.

In addition, since the porous nanoweb and the ion conductor constituting the polymer electrolyte membrane both use a hydrocarbon-based polymer material, the present invention has excellent adhesive strength, and thus, durability is excellent, and in addition, the conventional fluorine-based ion conductor or Teflon resin, etc. Because of using a relatively inexpensive hydrocarbon-based polymer material without using a has a good economical advantage in mass production.

Hereinafter, a method of manufacturing a polymer electrolyte membrane according to an embodiment of the present invention will be described. Detailed description of the same parts as described above, such as the type, weight ratio of the polymer will be omitted.

First, a method of preparing a polymer electrolyte membrane includes a process of preparing a porous nanoweb containing a hydrocarbon-based material insoluble in an organic solvent, and an ion conductor solution by dissolving an ion conductor containing a hydrocarbon-based material insoluble in an organic solvent in an organic solvent. It includes the process of manufacturing.

There is no special process sequence between the nanoweb preparation and the ion conductor solution preparation.

Since the porous nanoweb includes a hydrocarbon-based material that is insoluble in an organic solvent, the porous nanoweb may be prepared through a predetermined reaction after forming the nanoweb using a precursor soluble in the organic solvent.

Specifically, a precursor is prepared by dissolving a precursor in a spinning solvent, followed by electrospinning the prepared spinning solution to prepare a porous nanoweb made of nanofibers having an average diameter of 0.005 to 5 μm. Porous nanowebs can be prepared by post-treatment of nanowebs.

The porous nanoweb is manufactured through an electrospinning process to obtain high porosity and fine pores and thin films.

On the other hand, porous nano webs that are insoluble in organic solvents cannot be directly manufactured through an electrospinning process. In other words, the polyimide or polybenzoxazole forming the porous nanoweb is difficult to prepare a spinning solution because it is difficult to dissolve in a solvent of NMP, DMF, DMA, or DMSO.

Therefore, first, the precursor nanoweb is prepared by using a precursor that is well soluble in an organic solvent, and then the prepared precursor nanoweb is post-treated so that it is not dissolved in the organic solvent, thereby preparing a porous nanoweb which is insoluble in the organic solvent.

It may be preferred that the precursor has a moisture content of 0.5% or less. This is because, if the moisture content of the precursor exceeds 0.5%, the viscosity of the spinning solution may be lowered by the moisture, and the filament may be cut by the moisture after spinning, thereby decreasing processability and deteriorating physical properties by acting as a defect.

The post-treatment method for preparing the precursor nanoweb into the insoluble porous nanoweb includes a heat treatment method or a chemical treatment method. In particular, the heat treatment method may be performed using a hot press set to a high temperature and a high pressure.

It describes a method for producing a polyimide porous nanoweb as an embodiment of the present invention.

The polyimide porous nanoweb may be prepared by electrospinning a polyamicacid precursor to form a nanoweb precursor and then imidizing the nanoweb precursor using a hot press.

In more detail, a precursor solution is prepared by dissolving polyamic acid in a tetrahydrofuran (THF) solvent, and the precursor solution is sprayed at a temperature of 20 to 100 ° C. and a high voltage of 1 to 1,000 kPa. The polyimide porous nanoweb may be completed by forming a polyamic acid nanoweb on a collector by discharging it and then heat treating the polyamic acid nanoweb in a hot press set at a temperature of 80 to 400 ° C.

Polybenzoxazole porous nanoweb of another embodiment of the present invention, by using a polyhydroxyamide (polyhydroxyamide) precursor can be prepared by an electrospinning and heat treatment in a similar manner as described above.

As such, the polyimide or polybenzoxazole porous nanoweb having a high melting point and insoluble in an organic solvent serves to improve heat resistance, chemical resistance, and mechanical properties of the electrolyte membrane.

Next, the ion conductor solution is filled in the pores of the porous nanoweb.

The process of filling the ion conductor solution into the pores of the porous nanoweb may use a supporting process, but is not necessarily limited thereto, and various methods known in the art, such as a laminating process, a spray process, a screen printing process, a doctor blade process, and the like. The method can be used.

When using the immersion process, it is preferable to perform the immersion process 2 to 5 times for 5 to 30 minutes at room temperature.

After the ion conductor solution is filled, the organic solvent in the ion conductor solution is removed so that the ion conductor is filled in the pores of the porous nanoweb. The process of removing the organic solvent may be a process of drying for 2 to 5 hours in a 60 to 150 degree hot air oven.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are only intended to help the understanding of the present invention, and the scope of the present invention should not be limited.

Example  One

The polyamic acid / THF spinning solution having a concentration of 12% by weight was electrospun in a state where a voltage of 30 kV was applied, and then a polyamic acid nano web precursor was formed, followed by heat treatment in an oven at 350 ° C. for 15 hours Polyimide porous nanowebs with average thicknesses were prepared. At this time, the electrospinning was carried out in a state in which a voltage of 30 kW was applied in a spray jet nozzle at 25 ℃.

S-PEEK (sulfonated polyetheretherketone) was dissolved in N-methyl-2-pyrrolidinone (NMP) to prepare a 10 wt% ion conductor solution.

The porous nanoweb was immersed in the ion conductor solution. Specifically, the immersion process was performed three times at room temperature for 20 minutes. At this time, a reduced pressure atmosphere was applied for 1 hour to remove fine bubbles. Thereafter, the resultant was dried in a hot air oven maintained at 80 ° C. for 3 hours to remove NMP to prepare a polymer electrolyte membrane having an average thickness of 45 μm.

Example  2

In Example 1 described above, except that the average thickness of the porous nanoweb is changed to 10 μm by adjusting the electrospinning conditions, and the average thickness of the electrolyte membrane is changed to 50 μm by adjusting the amount of ion conductor impregnation. A polymer electrolyte membrane was prepared in the same manner as in 1.

Comparative example  One

S-PEEK (sulfonated polyetheretherketone) was dissolved in N-methyl-2-pyrrolidinone (NMP) to prepare a 15 wt% ion conductor solution. The film was formed on a glass plate using a doctor blade, and dried in a hot air oven maintained at 80 ° C. for 3 hours to remove NMP, thereby preparing a polymer membrane having a thickness of 50 μm.

Comparative example  2

After dissolving 25% by weight of polysulfone and 5% by weight of PVP in a DMAc solution, a film was formed using a doctor blade on a glass plate and immersed in water at room temperature. This was again immersed in ultrapure water for one day to remove the residual solvent and dried for 24 hours in hot air maintained at 80 ℃ to prepare a porous polysulfone membrane of 30 ㎛ thickness. The polysulfone porous membrane thus prepared was impregnated and dried in the same manner as in Example 1 to dry the Nafion solution in alcohol to prepare a polymer electrolyte membrane having an average thickness of 45 μm.

Comparative example  3

In Example 1, the electrospinning conditions were adjusted to change the average thickness of the porous nanoweb to 8 μm, and the average thickness of the polymer electrolyte membrane was changed to 50 μm by adjusting the amount of ion conductor impregnation. A polymer electrolyte membrane was prepared in the same manner as in Example 1.

The physical properties of the porous nanoweb and the porous polymer electrolyte membranes prepared by Examples and Comparative Examples were measured by the following method and are shown in Table 1 below.

Porous Nano Webs and Polymers Electrolyte membrane  Thickness (㎛)

The thickness of the sample 10 points was measured using a micrometer to evaluate the thickness of the porous nanoweb and the polymer electrolyte membrane as an average value.

% Thickness of nano web

As shown in FIG. 1, the average thickness (A) of the nanoweb and the average thickness (B + C) of the ion conductor (B + C) obtained through the cross-sectional photograph of the polymer electrolyte membrane obtained through the electron microscope, are used. The ratio was measured.

% Thickness of nanoweb = [A / (B + C)] × 100

Polymer Electrolyte membrane  Mechanical strength (MPa)

It was measured according to ASTM 638. At this time, specific measurement conditions are as follows.

Tensile Speed: 25 cm / min

Grip Spacing: 6.35 cm

Temperature and humidity: 25 ℃ × 50%

Polymer Electrolyte membrane  Thickness Expansion Rate (%)

Samples of 10 cm × 10 cm were prepared from the polymer electrolyte membranes obtained in Examples and Comparative Examples, and each sample was vacuum dried at 80 ° C. for 3 hours, and then the thickness (T 0) was measured. Subsequently, each sample was immersed in water at room temperature for 3 hours, then taken out to remove the surface water, and then the thickness (T1) was measured. Next, using the obtained sample thickness before and after swelling, the thickness expansion ratio (%) of the polymer electrolyte membrane was measured from the following equation.

Thickness Expansion Rate (%) = [(T1-T0) / T0)] × 100

Thickness ratio Mechanical strength (MPa) Thickness Expansion Rate (%) Example 1 50 25 5 Example 2 25 18 9 Comparative Example 1 0 8 37 Comparative Example 2 50 20 11 Comparative Example 3 19 12 13

A: average thickness of the nanoweb B: thickness of the upper ion conductor
C: thickness of lower ion conductor

Claims (13)

Porous nano webs having a melting point of 300 ° C. or higher and insoluble in organic solvents of NMP, DMF, DMA, or DMSO at room temperature; And
A polymer electrolyte membrane filled with pores of the porous nano-web, comprising an ion conductor containing a hydrocarbon-based material soluble in the organic solvent at room temperature. The method of claim 1,
The polymer electrolyte membrane is a polymer electrolyte membrane, characterized in that having a thickness expansion rate of 10% or less. The method of claim 1,
The polymer electrolyte membrane is a polymer electrolyte membrane, characterized in that the thickness ratio of the nanoweb measured by the formula below 20% or more.
Thickness ratio of nano web = [A / (B + C)] × 100
A is the average thickness of the nanoweb, B is the average thickness of the upper ion conductor, and C is the average thickness of the lower ion conductor. The method of claim 1,
The nanoweb is a polyimide (polyimide), polybenzoxazole (polybenzoxazole), a polymer electrolyte membrane comprising a copolymer or a mixture thereof. The method of claim 1,
The nanoweb is a polymer electrolyte membrane, characterized in that consisting of nanofibers having an average diameter of 0.005 to 5 ㎛. The method of claim 1,
The polymer web membrane, characterized in that the nanoweb has an average thickness of 1 to 20 ㎛. The method of claim 1,
The nanoweb has a porosity of 50 to 98% and an average diameter of pores is 0.05 to 30 ㎛ polymer electrolyte membrane. The method of claim 1,
The ion conductor is sulfonated polyimide (S-PI), sulfonated polyarylethersulfone (S-PAES), sulfonated polyetheretherketone (S-PEEK), sulfonated polybenzimidazole (S-PBI), sulfonated polysulfone (sulfonated polysulfone) : S-PSU), a sulfonated polystyrene (S-PS), a sulfonate polyphosphazene (sulfonated polyphosphazene) or a polymer electrolyte membrane comprising a mixture thereof. The method of claim 1,
The polymer electrolyte membrane is a polymer electrolyte membrane, characterized in that the mechanical strength is 10MPa or more. Preparing a spinning solution by dissolving a precursor in a spinning solvent;
Electrospinning the spinning solution to prepare a porous nanoweb made of nanofibers having an average diameter of 0.005 to 5 μm;
Post-processing the porous nanoweb such that the porous nanoweb is insoluble in an organic solvent of NMP, DMF, DMA, or DMSO;
Preparing an ion conductor solution by dissolving an ion conductor including a hydrocarbon-based material soluble in the organic solvent in the organic solvent; And
A polymer electrolyte comprising filling the ion conductor solution in the pores of the post-processed porous nanoweb so as to have a thickness ratio of 20% or more measured by the following equation, and then removing the organic solvent. membrane.
Thickness ratio of nano web = [A / (B + C)] × 100
A is the average thickness of the nanoweb, B is the average thickness of the upper ion conductor, and C is the average thickness of the lower ion conductor. The method of claim 10,
The precursor is a method of producing a polymer electrolyte membrane containing less than 0.5% by weight of water. The method of claim 10,
The post-treatment process includes a heat treatment process or a chemical treatment process. The method of claim 10,
The porous nanoweb is a method for producing a polymer electrolyte membrane comprising a polyimide (polyimide) or polybenzoxazole (polybenzoxazole).

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