KR20180047394A - Method of manufacturing polymer electrolyte membrane, polymer electrolyte membrane manufactured thereby, and membrane electrode assembly and fuel cell comprising the same - Google Patents

Abstract

The present invention relates to a method for producing a polymer electrolyte membrane, a polymer electrolyte membrane produced thereby, a membrane electrode assembly including the same, and a fuel cell. To this end, the method comprises the following steps: preparing the polymer electrolyte membrane; treating the polymer electrolyte membrane with acid; and washing the acid-treated polymer electrolyte membrane with ion-exchange water at least once. According to an embodiment of the present invention, the polymer electrolyte membrane ensures high ion exchange capacity.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polymer electrolyte membrane, a polymer electrolyte membrane produced thereby, and a membrane electrode assembly and a fuel cell comprising the membrane electrode assembly,

TECHNICAL FIELD The present invention relates to a method for producing a polymer electrolyte membrane, a polymer electrolyte membrane produced thereby, a membrane electrode assembly including the membrane electrode assembly and a fuel cell.

Recently, as the exhaustion of existing energy resources such as oil and coal is predicted, interest in energy that can replace them is increasing. As one of such alternative energies, fuel cells have attracted particular attention due to their advantages such as high efficiency, no emission of pollutants such as NOx and SOx, and abundant fuel.

A fuel cell is a power generation system that converts the chemical reaction energy of a fuel and an oxidant into electric energy. Hydrogen, hydrocarbons such as methanol and butane are used as fuel, and oxygen is used as an oxidant.

BACKGROUND ART Fuel cells include a polymer electrolyte fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell (PAFC), an alkaline fuel cell (AFC), a molten carbonate fuel cell (MCFC) And a battery (SOFC).

Korean Patent Publication No. 2003-0045324 (published on Jun. 11, 2003)

TECHNICAL FIELD The present invention relates to a method for producing a polymer electrolyte membrane, a polymer electrolyte membrane produced thereby, a membrane electrode assembly including the membrane electrode assembly and a fuel cell.

The present invention relates to a method for producing a polymer electrolyte membrane, comprising: preparing a polymer electrolyte membrane; Acid treating the polymer electrolyte membrane; And washing the acid-treated polyelectrolyte membrane with ion-exchanged water at least once. The present invention also provides a method for producing a polymer electrolyte membrane.

The present invention also provides a polymer electrolyte membrane produced by the above production method, wherein the sum of the concentrations of sodium cations and calcium cations in the polymer electrolyte membrane is 10000 mmol / g or less.

Further, the present specification provides a membrane electrode assembly including an anode, a cathode, and the polymer electrolyte membrane provided between the anode and the cathode.

Further, the present specification provides a fuel cell including the membrane electrode assembly.

The polymer electrolyte membrane according to the method of manufacturing a polymer electrolyte membrane of one embodiment of the present invention has an advantage that ion contamination due to impurities is reduced during the washing process.

The polymer electrolyte membrane according to the method for producing a polymer electrolyte membrane according to one embodiment of the present invention has an advantage of high ion exchange capacity.

1 is a schematic view showing an electricity generation principle of a fuel cell.
2 is a schematic view showing a structure of a membrane electrode assembly.
3 is a schematic view showing one embodiment of a fuel cell.
4 is a graph of ion conductivity of Example 1-2 and Comparative Example.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for producing a polymer electrolyte membrane, comprising: preparing a polymer electrolyte membrane; Acid treating the polymer electrolyte membrane; And washing the acid-treated polyelectrolyte membrane with ion-exchanged water at least once. The present invention also provides a method for producing a polymer electrolyte membrane.

The method of preparing the polymer electrolyte membrane may include preparing a polymer electrolyte membrane, and the prepared polymer electrolyte membrane may be a reinforced membrane impregnated with a polymer electrolyte on a porous support or a polymer electrolyte formed without a porous support.

The step of preparing the polymer electrolyte membrane may include the step of forming a polymer electrolyte membrane, or the step of preparing the prepared polymer electrolyte membrane.

In this case, the polymer electrolyte membrane before the acid treatment may be a polymer electrolyte membrane in which the sulfone group is mostly present in the polymer chain as -SO ₃ K, and the polymer electrolyte membrane having such a large amount of potassium cation is converted into the sulfonic acid group (-SO ₃ H) The conductivity of the fuel cell electrolyte membrane is lowered.

In one embodiment of the present invention, the polymer electrolyte membrane may be a hydrocarbon-based polymer electrolyte membrane, a partially fluorinated polymer electrolyte membrane, or a fluorinated polymer electrolyte membrane, and the electrolyte membrane may be a hydrocarbon-based polymer electrolyte membrane.

In one embodiment of the present invention, the polymer electrolyte composition forming the polymer electrolyte membrane may include a solvent and a polymer.

The polymer may be an ion conductive polymer, and conventional materials known in the art may be used.

The ion conductive polymer is not particularly limited as long as it is a substance capable of ion exchange, and those generally used in the art can be used.

The ion conductive polymer may be a hydrocarbon-based polymer, a partially fluorinated polymer, or a fluorinated polymer.

The hydrocarbon-based polymer may be a hydrocarbon-based sulfonated polymer having no fluorine group. On the contrary, the fluorine-based polymer may be a sulfonated polymer saturated with a fluorine group, and the partial fluorine-based polymer may be saturated with a fluorine group But may be a sulfonated polymer.

The ion conductive polymer may be at least one selected from the group consisting of perfluorosulfonic acid polymer, hydrocarbon polymer, aromatic sulfon polymer, aromatic ketone polymer, polybenzimidazole polymer, polystyrene polymer, polyester polymer, polyimide polymer, polyvinylidene fluoride Based polymers, polyether sulfone type polymers, polyphenylene sulfide type polymers, polyphenylene oxide type polymers, polyphosphazene type polymers, polyethylene naphthalate type polymers, polyester type polymers, doped polybenzimidazole type polymers, And may be one or two or more polymers selected from the group consisting of polyether ketone polymers, polyether ether ketone polymers, polyphenylquinoxaline polymers, polysulfone polymers, polypyrrole polymers and polyaniline polymers. The polymer may be sulfonated and may be a single copolymer, an alternating copolymer, a random copolymer, a block copolymer, a multi-block copolymer or a graft copolymer, but is not limited thereto.

The ion conductive polymer may be a polymer having cation conductivity, and examples thereof include naphion, perfluorosulfonic acid-based polymer, sulfonated polyetheretherketone (sPEEK), sulfonated polyetheretherketone (sPEK, sulfonated polyetherketone), polyvinylidene fluoride-graft-poly (styrene sulfonic acid), PVDF-g-PSSA) and sulfonated poly fluorenyl ether ketone)).

The weight average molecular weight of the polymer may range from tens of thousands to millions. Specifically, the polymer may have a weight average molecular weight of 10,000 or less.

The solvent for the polymer electrolyte membrane is not particularly limited as long as it is a substance capable of reacting with the polymer to dissolve the polymer, and conventional materials known in the art can be used.

The electrolyte membrane may be formed using the polymer electrolyte composition by a conventional method known in the art. For example, an electrolyte membrane may be formed by casting using the polymer electrolyte composition.

The method of manufacturing the polymer electrolyte membrane may include a step of acid-treating the prepared polymer electrolyte membrane. The acid treatment of the polyelectrolyte membrane can increase the concentration of sulfonic acid groups (-SO ₃ H) in the polymer electrolyte membrane through acid treatment.

The acid used in the acid treatment step may be at least one of sulfuric acid, nitric acid, hydrochloric acid, and a mixture thereof, and sulfuric acid may be used as the acid used in the acid treatment step.

In the step of acid-treating the polyelectrolyte membrane, the concentration of the acid may be 2M or less, and specifically, the concentration of the acid may be 0.5M or more and 2M or less.

In the step of acid-treating the polyelectrolyte membrane, the acid treatment temperature is 80 占 폚 or less, and specifically, the acid treatment temperature may be from room temperature to 80 占 폚.

In the step of acid-treating the polymer electrolyte membrane, the acid treatment time is within 24 hours, and the acid treatment time may be 1 hour to 24 hours.

The method of manufacturing the polymer electrolyte membrane may include washing the acid-treated polymer electrolyte membrane with ion exchange water at least once.

The washing may be performed at a room temperature for a period of time not exceeding one week.

The method of washing is not particularly limited, but it is possible to immerse an acid-treated polyelectrolyte membrane in a bath containing ion-exchanged water and wash it.

The ion-exchanged water in the washing step refers to water in which the ion-exchanged water has passed through a filter in which a cation-exchange resin and an anion-exchange resin are mixed. As the water passes through the filter, the cations in the water are replaced with hydrogen ions, and the anions in the water are replaced with hydroxide ions, so that the concentration of hydrogen ions and hydroxide ions in the passed water can be increased.

The ion-exchanged water in the washing step may be an ion-exchanged water which has passed through the filter mixed with the cation-exchange resin and the anion-exchange resin at least once, and the ion-exchanged water in the washing step may be at least one of the second order and the third order .

Here, the second order and the third order represent ion-exchanged water meeting the criteria in Table 1 below.

ASTM Water Grade Type I (3rd order)
-Ultra pure water- Type II (2nd order)
-High Pure water- Electrical Resistivity (Mohm.cm) 18.2 > 1.0 Electrical conductivity (uS / cm) 0.055 &Lt; 1.0 TOC (ppb) <10 <50 Na ⁺ , Cl ^- (ug / L) <1 <5 Germ (CFU / 10 mL) <1 na

* TOC: total organic carbon

Germ: colony-forming units per milliliter (microbes per unit volume, number of microorganisms)

The ion exchange water in the washing step may have a metal cation concentration of 100 mmol / g or less, specifically 0.1 mmol / g or more and 50 mmol / g or less.

In the present specification, the polymer electrolyte membrane prepared by the above-described production method may have a total concentration of sodium cations and calcium cations in the polymer electrolyte membrane of 10000 mmol / g or less, specifically 0.01 mmol / g or more and 5000 mmol / g or less have.

The percentage of the measured ion exchange capacity of the polymer electrolyte membrane may be 70% or more based on the theoretically calculated ion exchange capacity (IEC) in the synthesis of the ion conductive polymer constituting the polymer electrolyte membrane. At this time, a method for calculating the ion exchange capacity theoretically in the synthesis of the ion conductive polymer can be calculated according to the following formula 1.

[Equation 1]

The average thickness of the polymer electrolyte membrane may be 1 탆 or more and 100 탆 or less.

The present invention provides an electrochemical cell including an anode, a cathode, and the polymer electrolyte membrane provided between the anode and the cathode.

The cathode refers to an electrode that receives electrons when discharged, and may be an anode (oxidation electrode) that is oxidized when charged to emit electrons. The anode refers to an electrode which is oxidized when discharged to emit electrons, and may be a cathode (reduction electrode) that is reduced by receiving electrons when charged.

The electrochemical cell means a cell using a chemical reaction. The type of the electrochemical cell is not particularly limited as long as the polymer electrolyte membrane is provided. For example, the electrochemical cell may be a fuel cell, a metal secondary battery, or a flow cell.

The present invention provides an electrochemical cell module comprising an electrochemical cell as a unit cell.

The electrochemical cell module may be formed by stacking a bipolar plate between unit cells according to one embodiment of the present application.

The battery module may be specifically used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

The present invention provides a flow cell comprising an anode, a cathode, and the polymer electrolyte membrane provided between the anode and the cathode.

The flow cell of the present invention includes an anode tank and a cathode tank each storing an anode electrolyte or a cathode electrolyte; A pump connected to the anode tank and the cathode tank to supply the electrolyte solution to the anode or the cathode; An anode inlet and a cathode inlet through which the anode electrolytic solution or the cathode electrolytic solution flows respectively from the pump; And an anode outlet and a cathode outlet from which the electrolyte solution is discharged from the anode or the cathode to the anode tank and the cathode tank, respectively.

The present invention provides a membrane electrode assembly including an anode, a cathode, and the polymer electrolyte membrane provided between the anode and the cathode.

The present specification provides a fuel cell including the membrane electrode assembly. Specifically, the fuel cell may include at least two membrane electrode assemblies.

Said fuel cell comprising a stack comprising at least two membrane electrode assemblies according to this specification and a separator provided between membrane electrode assemblies; A fuel supply unit for supplying fuel to the stack; And an oxidant supply part for supplying the oxidant to the stack.

FIG. 1 schematically shows an electricity generating principle of a fuel cell. In a fuel cell, the most basic unit for generating electricity is a membrane electrode assembly (MEA), which includes an electrolyte membrane M and an electrolyte membrane M, And an anode (A) and a cathode (C) formed on both sides of the cathode (C). Referring to Fig. Showing the electricity generating principle of a fuel cell 1, an anode (A) in the hydrogen or methanol, butane and the oxidation of the fuel (F) of the hydrocarbon and so on up the hydrogen ions (H ⁺⁾ and electron (e ^-), such as And the hydrogen ions move to the cathode C through the electrolyte membrane M. In the cathode (C), the hydrogen ions transferred through the electrolyte membrane (M) react with the oxidizing agent (O) such as oxygen, and water (W) is produced. This reaction causes electrons to migrate to the external circuit.

The anode and the cathode each include an anode catalyst layer and a cathode catalyst layer, and the polymer electrolyte membrane may be provided between the anode catalyst layer and the cathode catalyst layer.

The anode catalyst layer and the cathode catalyst layer may include a catalyst and an ionomer, respectively.

Each of the catalyst inks forming the cathode catalyst layer and the anode catalyst layer may independently include a catalyst, an ionomer, and a solvent.

The catalyst may be one of platinum, a transition metal, and a platinum-transition metal alloy, although the type of the catalyst is not limited as long as it can serve as a catalyst in a fuel cell.

Here, the transition metal is an element of Group 3 to Group 11 in the periodic table, and may be any one of ruthenium, osmium, palladium, molybdenum and rhodium.

Specifically, the catalyst may be selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloy, platinum-osmium alloy, platinum-palladium alloy, platinum-molybdenum alloy and platinum-rhodium alloy. .

The catalysts can be used not only by themselves but also by being supported on a carbon-based carrier.

Examples of the carbon-based support include graphite, carbon black, acetylene black, denka black, cacao black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nano ring, A mixture of two or more selected from the group consisting of fullerene (C60) and Super P black (Super P black) is a preferred example.

The ionomer provides a path for ions generated by the reaction between the fuel and the catalyst, such as hydrogen or methanol, to move to the electrolyte membrane.

As the solvent contained in the catalyst ink, any one or a mixture of two or more selected from the group consisting of water, butanol, isopropanol, methanol, ethanol, n-propanol, n-butyl acetate and ethylene glycol is preferably used Can be used.

The process of introducing the catalyst layer can be performed by a conventional method known in the art. For example, the catalyst ink may be directly coated on the electrolyte membrane, or a catalyst layer may be formed on the releasable substrate, followed by thermocompression bonding to the electrolyte membrane, The catalyst layer may be formed by removing the substrate or by coating the gas diffusion layer. The method of coating the catalyst ink is not particularly limited, but spray coating, tape casting, screen printing, blade coating, inkjet coating, die coating or spin coating may be used.

The membrane electrode assembly further includes a cathode gas diffusion layer provided on a surface of the cathode catalyst layer opposite to a surface provided with an electrolyte membrane and an anode gas diffusion layer provided on a surface of the anode catalyst layer opposite to a surface provided with an electrolyte membrane can do.

The anode gas diffusion layer and the cathode gas diffusion layer are provided on one surface of the catalyst layer, respectively, and serve as a current conductor and have a porous structure as a reaction gas and a water passage. Therefore, the gas diffusion layer may include a conductive base material.

As the conductive base material, any conventional materials known in the art can be used. For example, carbon paper, carbon cloth or carbon felt can be preferably used. It does not.

The average thickness of the gas diffusion layer may be 100 占 퐉 or more and 500 占 퐉 or less. In this case, there is an advantage that the reactant gas transfer resistance through the gas diffusion layer is minimized and the optimum state is obtained from the viewpoint of proper water content in the gas diffusion layer.

2, the membrane electrode assembly may include an electrolyte membrane 10 and a cathode 50 and an anode 51 positioned opposite to each other with the electrolyte membrane 10 interposed therebetween. Specifically, the cathode includes a cathode catalyst layer 20 and a cathode gas diffusion layer 30 sequentially provided from the electrolyte membrane 10, and the anode includes an anode catalyst layer 21 and an anode catalyst layer 21 sequentially provided from the electrolyte membrane 10, And a gas diffusion layer 31.

3 schematically shows the structure of a fuel cell, which includes a stack 60, an oxidant supply unit 70, and a fuel supply unit 80. [

The stack 60 includes one or more of the membrane electrode assemblies described above and includes a separator interposed therebetween when two or more membrane electrode assemblies are included. The separator serves to prevent the membrane electrode assemblies from being electrically connected and to transfer the fuel and oxidant supplied from the outside to the membrane electrode assembly.

The oxidant supply part 70 serves to supply the oxidant to the stack 60. As the oxidizing agent, oxygen is typically used, and oxygen or air can be injected into the pump 70 and used.

The fuel supply unit 80 serves to supply the fuel to the stack 60 and includes a fuel tank 81 for storing the fuel and a pump 82 for supplying the fuel stored in the fuel tank 81 to the stack 60 Lt; / RTI &gt; As the fuel, gas or liquid hydrogen or hydrocarbon fuel may be used. Examples of hydrocarbon fuels include methanol, ethanol, propanol, butanol or natural gas.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following embodiments are intended to illustrate the present disclosure and are not intended to limit the present disclosure.

[Example]

[Example 1]

The polymer resin was dissolved in dimethylsulfoxide (DMSO) solvent in a desired ratio, filtered, and water was added thereto at a specific ratio to prepare a polymer solution. The polymer solution was used to cast a polymer film by a bar casting method, which was performed by using a doctor blade on a substrate of an applicator. The cast film was held in an applicator at 50 ° C for 2 hours or more and then dried in an oven at 100 ° C for a day.

The dried electrolyte membrane was immersed in a ₁ M sulfuric acid aqueous solution at 80 ° C to replace the sulfonic acid group with the -SO ₃ H form. After the acid treatment, the membrane was washed several times while immersed in the second order for 72 hours, and then dried at 80 ° C. to complete the electrolyte membrane.

At this time, the total cation concentration of the second order water was 50 mmol / g or less in total of sodium cation and calcium cation concentration.

[Example 2]

Example 1 was the same as Example 1 except that the acid-treated electrolyte membrane of Example 1 was washed with tertiary water and then dried at 80 캜 to complete an electrolyte membrane.

At this time, the cation concentration of the third order was 10 mmol / g or less, the sum of the sodium cation and the calcium cation concentration.

[Example 3]

The same as Example 1 except that the acid-treated electrolyte membrane of Example 1 was washed with tertiary order and the washing time was shortened to 30 minutes.

At this time, the total cation concentration of the tertiary ion-exchanged water was 10 mmol / g or less in total of sodium cation and calcium cation concentration.

[Comparative Example 1]

Example 1 was the same as Example 1 except that the acid-treated electrolyte membrane of Example 1 was washed with tap water and then dried at 80 캜 to complete an electrolyte membrane.

[Experimental Example 1]

After the electrolyte membrane is dried in a vacuum oven at 80 캜 for one day, the mass of the electrolyte membrane is measured. The electrolyte membrane is put into a supersaturated sodium chloride aqueous solution and stirred for one day. Titrate the hydrogen ion (H ⁺ ) in the electrolyte membrane with a 0.1 M solution of sodium hydroxide (OH ^- ) and calculate by the following formula.

IEC (meq./g) = ionic mmol concentration / mass of dry membrane

Name of sample Measurement IEC (mmal / g) Target IEC
(mmal / g) Measurement IEC / Target IEC (%) Comparative Example 1 0.488 1.919 25.4% Example 1 1.675 1.919 87.3% Example 2 1.818 1.919 94.7% Example 3 1.852 1.919 96.5%

IEC means the number of equivalents (mmol) of -SO ₃ H per g of polymer. From the results of Table 2, it can be seen that when washing with tap water, the sulfonic acid groups in the polymer electrolyte membrane were replaced with other cations due to a large amount of cations in the tap water.

Therefore, the number of -SO ₃ H equivalents in the electrolyte membrane was lowered and the IEC value was lowered.

In Example 1 using the second order, it can be confirmed that the sulfonic acid group was replaced with another cation in comparison with Example 2 using the third order.

It can be seen that the cleaning process after the acid treatment also affects the IEC value of the electrolyte membrane.

[Experimental Example 2]

1. Electrolyte Membrane Cation Analysis: ICP-OES (Optima 7300DV)

1) Aliquot 0.1 g of the sample in the platinum crucible.

2) Add 1.5 mL of concentrated sulfuric acid to the sample and heat it on a hot plate to carbonize the sample.

3) Heat up slowly from 260 ℃ to 430 ℃ in hot plate.

4) If sulfuric acid is removed because no white smoke is generated in the sample, stop heating and cool to room temperature.

5) Carbonize the sample slowly in an electric furnace to decompose organic matter.

- 1 step: carbonization temperature is 200 ℃, carbonization time is 1 hour

- 2 step: decomposition temperature is 400 ℃, decomposition time is 1 hour

- 3 step: decomposition temperature is 650 ℃, decomposition time is 3 hours

6) Add 2 mL of concentrated nitric acid and 0.5 mL of hydrogen peroxide to the residue, and heat / decompose.

7) Add 100 μL of internal standard Sc to the solution, and dilute to 10 mL with ultrapure water.

8) ICP-OES.

2. Analysis of anions in the electrolyte membrane

Approximately 30 mg of the sample was accurately measured on the sample boat and then measured by a combustion IC.

1) Combustion Ion Chromatograph ICS-5000, Combustion Device: AQF-2100

- Combustion temperature: Inlet temperature 900 ℃, Outlet temperature 1 000 ℃

- Gas flow rate: Ar gas 200 mL / min, O2 gas 400 mL / min, Humidity: 0.23 mL / min

- Internal standard (PO ₄ ^3- ): 20 mg / kg, Absorbent (H ₂ O ₂ ): 900 mg / kg

- Absorbent volume: 5 mL, final dilution volume: 10 mL

Column: IonPac AS18 (4 x 250 mm), Eluent type: KOH (30.5 mM), Eluent flow rate: 1 mL / min

- Detector: Suppressed Conductivity Detector, SRS Current: 76 mA, Injection volumn: 20 μL

- Isocratic / Gradient Condition: Isocratic

2) Analysis equipment: Ion Chromatograph: ICS-3000

- Column: IonPac CS12A analytical (4 x 250 mm), IonPac CG12A guard (4 x 50 mm)

- Eluent type: MSA (Methanesulfonic acid, 20 mM)

- Eluent flow rate: 1 mL / min

- Detector: Suppressed Conductivity Detector

- SRS Current: 59mA

- Injection volumn: 25 μL

- Isocratic / Gradient Condition: isocratic

It can be seen from Table 3 and Table 4 that the cation in the washing water (-SO ₃ X; X = Na, Mg, K, Ca, ...) is substituted for the sulfonic acid group (-SO ₃ H) there was. In particular, when washed with tap water, a large amount of positive ions were detected in the electrolyte membrane as compared with the case of using the second and third order electrolytes, and the concentration of sulfonic acid in the electrolyte membrane was decreased due to such contamination, .

[Experimental Example 3]

The results of measurement of the ionic conductivity of the electrolyte membranes of Examples 1-2 and Comparative Example 1 are shown in Fig.

The ionic conductivity of the electrolyte membrane was measured using the 4-proce method. The frequency range was measured by a complex impedance method between 10 Hz and 1 MHz and the Nyquist plots were plotted to obtain the bulk resistance value.

The ionic conductivity of the electrolyte membrane was calculated by Equation 2 below. Where L is the distance between the two sensor electrodes is fixed at 0.425.

R is the bulk resistance of the electrolyte membrane, w is the width of the electrolyte membrane, and t is the thickness of the electrolyte membrane.

[Formula 2]

Ion conductivity (?) = [{L / (R x w x t)} x 100]

In contrast to the IEC results in Table 1 above, it can be seen from the ionic conductivity results that the higher the sulfone equivalent is, the more efficient the proton path.

In particular, cleaning with tap water causes cation contamination in the electrolyte membrane, which decreases the efficiency of the proton path and ultimately affects fuel cell performance.

10: electrolyte membrane
20: cathode catalyst layer
21: anode catalyst layer
30: cathode gas diffusion layer
31: anode gas diffusion layer
50: cathode
51: anode
60: Stack
70: oxidant supplier
80: fuel supply unit
81: Fuel tank
82: Pump

Claims (6)

Preparing a polymer electrolyte membrane;
Acid treating the polymer electrolyte membrane; And
And washing the acid-treated polyelectrolyte membrane with ion-exchange water at least once. The method for producing a polymer electrolyte membrane according to claim 1, wherein the ion exchange water in the washing step is at least one of a second order and a third order. The method for producing a polymer electrolyte membrane according to claim 1, wherein the ion exchange water in the washing step has a metal cation concentration of 100 mmol / g or less. A polymer electrolyte membrane produced by the production method according to any one of claims 1 to 3,
Wherein the sum of the concentrations of the sodium cation and the calcium cation in the polymer electrolyte membrane is 10000 mmol / g or less. A membrane electrode assembly comprising an anode, a cathode, and a polymer electrolyte membrane according to claim 4 provided between the anode and the cathode. A fuel cell comprising the membrane electrode assembly of claim 5.

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