KR102212930B1 - composite for production of perfluorinated sulfonic acid ionomer, perfluorinated sulfonic acid ionomer using the same, complex electrolyte membrane for PEMFC containing the same and membrane electrode assembly for PEMFC containing the same - Google Patents

Abstract

The present invention relates to a composition for preparing a perfluorine-based sulfonated ionomer, a perfluorine-based sulfonated ionomer using the same, a composite electrolyte membrane for PEMFC comprising the same, and a membrane-electrode assembly for PEMFC comprising the same, and has excellent safety and durability. The improved composition for preparing a perfluorine-based sulfonated ionomer, a perfluorine-based sulfonated ionomer using the same, a composite electrolyte membrane for PEMFC including the same, and a membrane-electrode assembly for PEMFC including the same.

Description

A composition for producing a perfluorinated sulfonated ionomer, a perfluorinated sulfonated ionomer using the same, a composite electrolyte membrane for PEMFC comprising the same, and a membrane-electrode assembly for PEMFC comprising the same (composite for production of perfluorinated sulfonic acid ionomer, perfluorinated sulfonic acid ionomer using the same, complex electrolyte membrane for PEMFC containing the same and membrane electrode assembly for PEMFC containing the same}

The present invention relates to a composition for preparing a perfluorine-based sulfonated ionomer, a perfluorine-based sulfonated ionomer using the same, a composite electrolyte membrane for PEMFC comprising the same, and a membrane-electrode assembly for PEMFC comprising the same, and has excellent safety and durability. The improved composition for preparing a perfluorine-based sulfonated ionomer, a perfluorine-based sulfonated ionomer using the same, a composite electrolyte membrane for PEMFC including the same, and a membrane-electrode assembly for PEMFC including the same.

A fuel cell is a power generation system that directly converts chemical energy generated by electrochemically reacting fuel (hydrogen or methanol) and oxidizing agent (oxygen) into electrical energy.It is a next-generation energy source with high energy efficiency and eco-friendly features with low pollutant emissions. It is being researched and developed. Fuel cells can be used by selecting high temperature and low temperature fuel cells depending on the application field, and are usually classified according to the type of electrolyte. For high temperature use, solid oxide fuel cells (SOFC), molten carbonate There are fuel cells (Molten Carbonate Fuel Cell, MCFC), etc., and for low temperature applications, Alkaline Fuel Cell (AFC) and Polymer Electrolyte Membrane Fuel Cell (PEMFC) are being developed as a representative.

If the polymer electrolyte fuel cell is subdivided, a hydrogen ion exchange membrane fuel cell (PEMFC, Proton Exchange Membrane Fuel Cell) that uses hydrogen gas as fuel, and direct methanol that is used by supplying liquid methanol directly to the anode as fuel. Fuel cells (Direct Methanol Fuel Cell, DMFC). Polyelectrolyte fuel cells are in the spotlight as portable, vehicle, and home power supplies for their advantages such as low operating temperature of less than 100°C, excluding leakage problems due to the use of solid electrolytes, fast starting and response characteristics, and excellent durability. In particular, as a high-power fuel cell having a larger current density than other types of fuel cells, research into a portable fuel cell is continuing because it can be miniaturized.

The unit cell structure of such a fuel cell has a structure in which an anode (anode) and a cathode (oxygen electrode) are coated on both sides of an electrolyte membrane made of a polymer material, which is a membrane-electrode assembly. Electrode Assembly, MEA). This membrane-electrode assembly (MEA) is a part in which an electrochemical reaction between hydrogen and oxygen occurs, and is composed of a cathode, an anode, and an electrolyte membrane, that is, an ion conductive electrolyte membrane (eg, a hydrogen ion conductive electrolyte membrane).

Hydrogen or methanol, which is a fuel, is supplied from the oxidation electrode to generate hydrogen ions and electrons through the oxidation reaction of hydrogen, and hydrogen ions and oxygen that have passed through the polymer electrolyte membrane are combined to generate water by the reduction reaction of oxygen. .

In this membrane-electrode assembly, the electrode catalyst layers of the anode and the cathode are coated on both sides of the ion conductive electrolyte membrane, and the material constituting the electrode catalyst layer is Pt (platinum) or Pt-Ru (platinum-ruthenium). The catalyst material of is supported on a carbon carrier. Membrane-electrode assembly (MEA), which can be seen as a key component of the electrochemical reaction of fuel cells, uses ion-conducting electrolyte membranes and platinum catalysts, which have a high price-to-price ratio, and is directly connected to power production efficiency. It is regarded as the most important part in improving the performance and price competitiveness of

The conventional method of manufacturing MEA, which is generally used, is to prepare a paste by mixing a catalyst material, a hydrogen ion conductive binder, that is, a fluorine-based Nafion ionomer, and a water and/or alcohol solvent, This is coated with carbon cloth or carbon paper, which is an electrode support supporting the catalyst layer and also serves as a gas diffusion layer, and then dried and thermally fused to a hydrogen ion conductive electrolyte membrane.

In the catalyst layer, a redox reaction of hydrogen and oxygen by a catalyst; Movement of electrons by adhered carbon particles; Supply of hydrogen, oxygen and moisture, and securing a passage for discharging excess gas after the reaction; The movement of oxidized hydrogen ions, etc. must occur simultaneously. In order to improve performance, activation polarization should be reduced by increasing the area of the triple phase boundary where the feed fuel meets the catalyst and the ion conductive polymer electrolyte membrane, and the interface between the catalyst layer and the electrolyte membrane and the catalyst layer. The interface between the gas diffusion layer and the gas diffusion layer must be uniformly bonded to reduce ohmic polarization at the interface. Therefore, in order to improve the performance of the fuel cell by reducing the interfacial resistance between the catalyst layer and the electrolyte membrane as much as possible, not only must there be bonding strength between the catalyst layer and the electrolyte membrane during MEA manufacturing, but also the interfacial bonding between the catalyst layer and the electrolyte membrane during fuel cell operation. It must be maintained.

Accordingly, in recent years, technology has been actively developed for uniformly bonding the interface between the catalyst layer and the electrolyte membrane and the interface between the catalyst layer and the gas diffusion layer, but the interface uniformity is still limited.

In addition, in the case of the MEA having the above-described structure, since an electrolyte membrane having a thick thickness is generally used, transmission of hydrogen ions may be delayed, resulting in performance degradation.

In addition, when the fuel cell is driven, as the movement of hydrogen ions and the use time increase, the interface between the catalyst layer and the electrolyte membrane and the interface bonding between the catalyst layer and the gas diffusion layer are weakened, and thus they are separated from each other. Accordingly, when applied to a fuel cell, the performance of the fuel cell may be deteriorated.

In order to shorten the transfer time of hydrogen ions, etc., the thickness of the electrolyte membrane must be reduced, and for this purpose, there is a method of thinning the thickness of the porous support constituting the electrolyte membrane.In order to decrease the thickness of the support, physical properties such as strength of the support during high stretching In addition to this greatly reduced, there was a problem in that economic feasibility and commerciality were deteriorated due to a high defect rate in manufacturing the support.

US Patent No. US3282875 (Registration Date: 1966.11.01)

The present invention includes a composition for producing a perfluorine-based sulfonated ionomer having excellent physical properties, a composition for producing a perfluorine-based sulfonated ionomer having improved stability and durability of a composite electrolyte membrane for PEMFC, and a perfluorine-based sulfonated composition using the same. It is intended to provide an ionomer, a composite electrolyte membrane for PEMFC including the same, and a membrane-electrode assembly for PEMFC including the same.

In order to solve the above-described problems, the composition for producing a perfluorine-based sulfonated ionomer of the present invention may include tetrafluoroethylene (TFE), a compound represented by the following formula 1, a compound represented by the following formula 2, and a radical initiator. .

[Formula 1]

In Formula 1, a is 1 or 2.

[Formula 2]

In a preferred embodiment of the present invention, the radical initiator is a bis (fluoroacyl) peroxide compound, a bis (chlorofluoroacyl) peroxide compound, a dialkyl peroxydicarbonate compound, a diacyl peroxide compound, It may include at least one selected from peroxyester-based compounds, azo-based compounds, and persulfate-based compounds.

In a preferred embodiment of the present invention, the composition for preparing a perfluorinated sulfonated ionomer of the present invention may further include a hydrolyzing agent and an oxidizing agent.

In a preferred embodiment of the present invention, the compound represented by Formula 1-1 and the compound represented by Formula 2 may be included in a weight ratio of 1:0.45 to 1.32.

[Formula 1-1]

In Formula 1-1, a is 1.

In a preferred embodiment of the present invention, the compound represented by Formula 1-2 and the compound represented by Formula 2 may be included in a weight ratio of 1:0.50 to 1.96.

[Formula 1-2]

In Formula 1-2, a is 2.

Meanwhile, the perfluorine-based sulfonated ionomer of the present invention may include a polymer including a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5).

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

In a preferred embodiment of the present invention, the polymer includes a repeating unit represented by Formula 6 below, and the polymer may have a weight average molecular weight of 20,000 to 10,000,000.

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are rational numbers of 1: 0.01 to 1: 0.01 to 1 as a molar ratio, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified.

In a preferred embodiment of the present invention, the polymer may have a chemical equivalent (EW: equivalent weight) of -SO ₃ H group of 500 to 1200.

Further, the composite electrolyte membrane for PEMFC of the present invention may include a support layer, a first electrolyte layer formed on one surface of the support layer, and a second electrolyte layer formed on the other surface of the support layer.

In a preferred embodiment of the present invention, at least one of the first and second electrolyte layers may contain the perfluorine-based sulfonated ionomer of the present invention.

In a preferred embodiment of the present invention, the composite electrolyte membrane for PEMFC of the present invention may have a durability measured by a Fenton test of 1.5 to 10.0 μmol/hr·g.

In a preferred embodiment of the present invention, the composite electrolyte membrane for PEMFC of the present invention may have an ionic conductivity of 0.07 to 0.2 S/cm.

Meanwhile, the membrane-electrode assembly for PEMFC of the present invention may include an anode (anode), a composite electrolyte membrane for PEMFC of the present invention, and a cathode (reduction electrode).

In a preferred embodiment of the present invention, the membrane-electrode assembly for PEMFC of the present invention may have a hydrogen permeability of 1.0 to 2.6 mA/cm².

Further, the polymer electrolyte membrane fuel cell of the present invention includes the membrane-electrode assembly and separator for PEMFC of the present invention, an electricity generation unit that generates electricity through an electrochemical reaction between fuel and an oxidizing agent, and supplies fuel to the electricity generation unit. It may include a fuel supply unit and an oxidizing agent supply unit for supplying the oxidizing agent to the generator.

On the other hand, the method for preparing a perfluorinated sulfonated ionomer of the present invention is a first step of introducing and stirring deionized water, a compound represented by the following formula 1, and a compound represented by the following formula 2, tetrafluoro. A second step of replacing the internal atmosphere of the reactor with a TFE gas atmosphere by introducing ethylene (TFE) gas into the reactor, and preparing a compound containing -SO ₂ F by introducing a radical initiator into the reactor Step 3 and immersing the compound containing the -SO ₂ F group in a solution containing a hydrolyzing agent to prepare a compound containing a sulfonate group, and immersing the compound containing the sulfonate group in a solution containing an oxidizing agent A fourth step of preparing a polymer including a repeating unit represented by Formula 3 below, a repeating unit represented by Formula 4 below, and a repeating unit represented by Formula 5 below may be included.

[Formula 1]

In Formula 1, a is 1 or 2.

[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

In a preferred embodiment of the present invention, the polymer of the method for producing a perfluorine-based sulfonated ionomer of the present invention includes a repeating unit represented by Formula 6 below, and the polymer may have a weight average molecular weight of 20,000 to 10,000,000.

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are rational numbers of 1: 0.01 to 1: 0.01 to 1 as a molar ratio, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified.

Further, another method for producing a perfluorine-based sulfonated ionomer according to the present invention includes a first step of introducing and stirring deionized water and a compound represented by the following formula (1), tetrafluoroethylene (TFE) gas. The second step of introducing into the reactor to replace the internal atmosphere of the reactor with a TFE gas atmosphere, the third step of introducing a radical initiator into the reactor, and introducing and stirring a compound represented by the following formula (2) into the reactor The fourth step of preparing a compound containing -SO ₂ F group and the compound containing the -SO ₂ F group are immersed in a solution containing a hydrolyzing agent to prepare a compound containing a sulfonic acid group, and the sulfonic acid group A fifth step of preparing a polymer including a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5) by immersing the containing compound in a solution containing an oxidizing agent Can include.

[Formula 1]

In Formula 1, a is 1 or 2.

[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

In a preferred embodiment of the present invention, the polymer of the method for producing another perfluorinated sulfonated ionomer of the present invention includes a repeating unit represented by the following Formula 6, and the polymer may have a weight average molecular weight of 20,000 to 10,000,000.

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are rational numbers of 1: 0.01 to 1: 0.01 to 1 as a molar ratio, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified.

The composite electrolyte membrane for PEMFC containing the perfluorine-based sulfonated ionomer of the present invention has excellent ionic conductivity, and thus, a Proton Exchange Membrane Fuel Cell (PEMFC) using the same can have excellent physical properties.

In addition, the composite electrolyte membrane for PEMFC including the perfluorine-based sulfonated ionomer of the present invention has a high moisture content, so it is easy to process and improves hydrogen permeability.

In addition, the composite electrolyte membrane for PEMFC including the perfluorine-based sulfonated ionomer of the present invention has excellent safety and improved durability.

1 is a schematic diagram of a composite electrolyte membrane for PEMFC according to a preferred embodiment of the present invention.
2 is a schematic diagram of a membrane-electrode assembly for PEMFC according to a preferred embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are added to the same or similar components throughout the specification.

First, a perfluorinated sulfonic acid ionomer (PFSA ionomer) of the present invention will be described.

The perfluorine-based sulfonated ionomer of the present invention is an ionomer contained in the electrolyte layer of the composite electrolyte membrane for PEMFC of the present invention to be described later, and is represented by a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and the following formula (5). It may include a polymer containing a repeating unit, preferably a polymer containing a repeating unit represented by the following formula (6).

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, and x, y and z are molar ratios, 1: 0.01 to 1: rational number of 0.01 to 1, preferably 1: 0.05 to 0.3: rational number of 0.025 to 0.1, further Preferably, it may be a rational number of 1: 0.1 to 0.2: 0.045 to 0.075, even more preferably 1: 0.1 to 0.2: a rational number of 0.045 to 0.065, even more preferably 1: 0.1 to 0.15: 0.045 to 0.055 rational number. .

If the molar ratio of x and y is less than 1:0.01, there may be a problem of ionic conductivity, and if it exceeds 1:1, there may be problems such as compatibility, film forming characteristics, moldability and durability. In addition, if the molar ratio of x and z is less than 1:0.01, there may be a problem of ionic conductivity, and if it exceeds 1:1, there may be a problem of durability.

In addition, in Formula 6, the order of bonding of each constituent unit according to x, y, and z may be randomly modified.

In addition, the polymer of the perfluorinated sulfonated ionomer of the present invention has a weight average molecular weight of 20,000 to 10,000,000, preferably a weight average molecular weight of 30,000 to 8,000,000, more preferably a weight average molecular weight of 50,000 to 1,000,000, and even more preferably a weight average molecular weight of 50,000 to 800,000, even more preferably, the weight average molecular weight may be 100,000 to 300,000.If the weight average molecular weight of the polymer is less than 20,000, there may be problems in durability and mechanical properties, and if the weight average molecular weight exceeds 10,000,000, there may be a problem of moldability. I can.

In addition, the perfluorine-based sulfonated ionomer of the present invention has a chemical equivalent (EW: equivalent weight) of the -SO ₃ H group of 500 to 1200, preferably 550 to 850, more preferably 620 to 730, even more preferably 640. ~ 730, even more preferably 680 ~ 720, if the chemical equivalent of -SO ₃ H group is less than 500, there may be problems in durability and mechanical properties, and if it exceeds 1200, there may be problems in ion conductivity. have.

On the other hand, the above-mentioned perfluorinated sulfonated ionomer of the present invention is a composition for preparing a perfluorine-based sulfonated ionomer comprising tetrafluoroethylene (TFE), a compound represented by the following Formula 1, a compound represented by the following Formula 2, and a radical initiator It can be manufactured using.

[Formula 1]

In Formula 1, a is 1 or 2.

[Formula 2]

In addition, the composition for preparing a perfluorine-based sulfonated ionomer of the present invention may include a compound represented by Formula 1 and a compound represented by Formula 2 in a weight ratio of 1:0.45 to 1.32, and if, the compound represented by Formula 2 If the content is less than 0.45 weight ratio, there may be a problem of ionic conductivity, and if it exceeds 1.32 weight ratio, there may be a problem of durability degradation.

Specifically, the composition for preparing a perfluorine-based sulfonated ionomer of the present invention comprises a compound represented by the following Formula 1-1 and a compound represented by Formula 2 in a weight ratio of 1: 0.45 to 1.32 weight ratio, preferably 1: 0.6 to 1.32 weight ratio, further Preferably, it may be included in a weight ratio of 1: 0.7 to 1.1, even more preferably 1: 0.71 to 0.85.

[Formula 1-1]

In Formula 1-1, a is 1.

In addition, the composition for preparing a perfluorine-based sulfonated ionomer of the present invention comprises a compound represented by the following Formula 1-2 and a compound represented by Formula 2 in a weight ratio of 1: 0.50 to 0.96, preferably 1: 0.52 to 0.80 by weight, more preferably It may be included in a weight ratio of 1: 0.53 to 0.62.

[Formula 1-2]

In Formula 1-2, a is 2.

The radical initiator of the composition for producing a perfluorine-based sulfonated ionomer of the present invention plays a role in causing radical chain polymerization by generating a radical, as a bis (fluoroacyl) peroxide compound, a bis (chlorofluoroacyl) peroxide It may include at least one selected from among compounds based on compounds, dialkyl peroxydicarbonates, diacyl peroxide compounds, peroxyester compounds, perfluoroperoxide compounds, azo compounds and persulfate compounds, and is preferred. For example, it may include one or more selected from perfluoroperoxide-based compounds and persulfate-based compounds.

As a dialkyl peroxydicarbonate-based compound, it may contain at least one selected from dimethyl peroxydicarbonate, diethyl peroxydicarbonate, and dipropyl peroxydicarbonate, and diacyl peroxide Diacetyl peroxide may be included as a compound, and bis (pentafluoro propionyl) peroxide (Bis (Pentafluoro propionyl) peroxide), bis (trifluoromethyl) peroxide as a peroxy ester compound It may contain at least one selected from oxyanhydride (Bis (trifluoromethyl) peroxyanhydride), and as a perfluoroperoxide-based compound, bis (perfluoro-t-butyl) peroxide (Bis (perfluoro-t-butyl) Peroxide), bis (trifluoromethyl) peroxide (Bis (trifluoromethyl) Peroxide) may contain at least one selected from, as an azo-based compound, azobis-2-methylpropane nitrile (Azobisisobutyronitrile, AIBN) It may include, and may include at least one selected from potassium persulfate (KPS) and ammonium persulfate (APS) as a persulfate-based compound.

On the other hand, the composition for preparing a perfluorine-based sulfonated ionomer of the present invention may further include deionized water.

In addition, the composition for preparing a perfluorinated sulfonated ionomer of the present invention of the present invention may further include a hydrolyzing agent and an oxidizing agent.

The hydrolyzing agent is -SO ₂ F group prepared by polymerization of tetrafluoroethylene (TFE) contained in the composition for preparing a perfluorinated sulfonated ionomer, the compound represented by Formula 1, and the compound represented by Formula 2 As a function of converting the containing compound into a compound containing a sulfonate group by hydrolysis, a basic compound may be included. In this case, as the basic compound, at least one selected from lithium hydroxide, sodium hydroxide and potassium hydroxide may be included, and lithium hydroxide may be preferably included.

The oxidizing agent serves to convert a compound containing a sulfonate group prepared through a hydrolyzing agent into a compound containing a -SO ₃ H group, and may include at least one selected from hydrochloric acid and sulfuric acid.

On the other hand, as a preferred embodiment of the method for producing a perfluorinated sulfonated ionomer of the present invention, it includes the first step to the fourth step.

First, as the first step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, deionized water, a compound represented by the following formula 1, and a compound represented by the following formula 2 can be added and stirred into the reactor. have.

[Formula 1]

In Formula 1, a is 1 or 2.

[Formula 2]

At this time, preferably an autoclave may be used as the reactor, and the stirring is 150 to 450 rpm, preferably 200 to 400 rpm, more preferably 250 to 350 rpm, for 15 minutes to 45 minutes, preferably It may be performed for 20 minutes to 40 minutes, more preferably 25 to 35 minutes.

In addition, the compound represented by Formula 1 and the compound represented by Formula 2 introduced into the reactor may be added in a weight ratio of 1:0.45 to 1.32.

Specifically, the compound represented by the following formula 1-1 and the compound represented by the formula 2 are 1:0.45 to 1.32 weight ratio, preferably 1: 0.6 to 1.32 weight ratio, more preferably 1: 0.7 to 1.1 weight ratio, even more Preferably, it may be added in a weight ratio of 1: 0.71 to 0.85.

[Formula 1-1]

In Formula 1-1, a is 1.

In addition, the compound represented by the following formula 1-2 and the compound represented by the formula 2 are 1: 0.50 to 0.96 weight ratio, preferably 1: 0.52 to 0.80 weight ratio, more preferably 1: 0.53 to 0.62 weight ratio I can.

[Formula 1-2]

In Formula 1-2, a is 2.

After performing the first step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the inside of the reactor can be vacuumed to remove moisture, and then purged with nitrogen gas (same process as above). Can be performed by repeating 2 to 5 times.)

Next, as a second step of the method for producing a perfluorinated sulfonated ionomer of the present invention, tetrafluoroethylene (TFE) gas is introduced into the reactor to replace the internal atmosphere of the reactor with a TFE gas atmosphere. I can.

Specifically, in the second step, first, TFE gas is introduced into the reactor, and the pressure inside the reactor is replaced with a TFE gas atmosphere of 0.005 to 0.1 MPa, preferably 0.007 to 0.05 MPa, more preferably 0.008 to 0.03 MPa. can do.

Next, the inside of the reactor is vacuumed to remove moisture, and after that, the TFE gas until the pressure inside the reactor is 0.4 to 1.2 MPa, preferably 0.6 to 1.0 MPa, more preferably 0.7 to 0.9 MPa. Can be introduced into the reactor.

Finally, heat is applied to the inside of the reactor at a rate of 3° C./min to 7° C./min, preferably 4° C./min to 6° C./min, so that the temperature inside the reactor is 30 to 40° C., preferably 33 to 37. The temperature can be raised until it reaches °C.

Next, as a third step of the method for producing a perfluorinated sulfonated ionomer of the present invention, a radical initiator may be added to the inside of the reactor to prepare a compound containing -SO ₂ F.

As mentioned above, the radical initiator is a bis (fluoroacyl) peroxide compound, a bis (chlorofluoroacyl) peroxide compound, a dialkyl peroxydicarbonate compound, a diacyl peroxide compound, a peroxy ester compound, It may include at least one selected from perfluoroperoxide-based compounds, azo-based compounds, and persulfate-based compounds, and preferably at least one selected from perfluoroperoxide-based compounds and persulfate-based compounds, and , The radical initiator may be mixed with deionized water and used as a radical initiator solution. In this case, the radical initiator solution may contain 0.1 to 2% by weight of the radical initiator, preferably 0.5 to 1.5% by weight.

On the other hand, when preparing a compound containing -SO ₂ F group through the third step of the method for producing a perfluorinated sulfonated ionomer of the present invention, the inside of the reactor is 3 ℃ / min ~ 7 ℃ / min, preferably 4 ℃ By applying heat at a rate of /min ~ 6℃/min, the temperature inside the reactor is raised to 40 ~ 60°C, preferably 45 ~ 55°C, and it can be maintained until the production reaction is terminated. The reaction may be carried out for 1 to 5 hours, preferably 2 to 4 hours.

Additionally, the compound containing the -SO ₂ F group prepared in the third step may be repeatedly washed with distilled water to remove foreign matter and unreacted material.

Finally, as a fourth step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the compound containing the -SO ₂ F group prepared in the third step is immersed in a solution containing a hydrolyzing agent to contain a sulfonate group. A compound is prepared, and the compound containing the sulfonate group is immersed in a solution containing an oxidizing agent to include a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5) The polymer can be prepared, and preferably a polymer including a repeating unit represented by the following formula (6) can be prepared.

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, and x, y and z are molar ratios, 1: 0.01 to 1: rational number of 0.01 to 1, preferably 1: 0.05 to 0.3: rational number of 0.025 to 0.1, further Preferably 1: 0.1 to 0.2: 0.045 to 0.075 rational number, even more preferably 1: 0.1 to 0.2: 0.045 to 0.065 rational number, even more preferably 1: 0.1 to 0.15: 0.045 to 0.055 rational number, The order of bonding of each constituent unit according to, x, y and z may be randomly modified.

In addition, the polymer has a weight average molecular weight of 20,000 to 10,000,000, preferably a weight average molecular weight of 30,000 to 8,000,000, more preferably a weight average molecular weight of 50,000 to 1,000,000, even more preferably a weight average molecular weight of 50,000 to 800,000, even more preferably a weight average It may have a molecular weight of 100,000 to 300,000.

Specifically, in the fourth step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the compound containing the -SO ₂ F group prepared in the third step is hydrolyzed through a hydrolyzing agent to form the -SO ₂ F group as a sulfonate group. It is a process of substituting and replacing the sulfonate group with -SO ₃ H group through an oxidizing agent.

A solution containing a hydrolyzing agent is a substance in which the aforementioned hydrolyzing agent is mixed in a solvent, and a solution containing an oxidizing agent is a substance in which the aforementioned oxidizing agent is mixed in a solvent, and the solvent is water or water and a polar solvent. It may be a mixed solvent. As a polar solvent, alcohols (methanol, ethanol, etc.) or dimethyl sulfoxide may be used.

Further, as another preferred embodiment of the method for producing a perfluorinated sulfonated ionomer of the present invention, it includes the first to fifth steps.

First, as a first step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, deionized water and a compound represented by the following formula (1) may be added and stirred into the reactor.

[Formula 1]

In Formula 1, a is 1 or 2.

At this time, preferably an autoclave may be used as the reactor, and the stirring is 150 to 450 rpm, preferably 200 to 400 rpm, more preferably 250 to 350 rpm, for 15 minutes to 45 minutes, preferably It may be performed for 20 minutes to 40 minutes, more preferably 25 to 35 minutes.

After performing the first step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the inside of the reactor can be vacuumed to remove moisture, and then purged with nitrogen gas (same process as above). Can be performed by repeating 2 to 5 times.)

Next, as a second step of the method for producing a perfluorinated sulfonated ionomer of the present invention, tetrafluoroethylene (TFE) gas is introduced into the reactor to replace the internal atmosphere of the reactor with a TFE gas atmosphere. I can.

Specifically, in the second step, first, TFE gas is introduced into the reactor, and the pressure inside the reactor is replaced with a TFE gas atmosphere of 0.005 to 0.1 MPa, preferably 0.007 to 0.05 MPa, more preferably 0.008 to 0.03 MPa. can do.

Next, the inside of the reactor is vacuumed to remove moisture, and after that, the TFE gas until the pressure inside the reactor is 0.4 to 1.2 MPa, preferably 0.6 to 1.0 MPa, more preferably 0.7 to 0.9 MPa. Can be introduced into the reactor.

Finally, heat is applied to the inside of the reactor at a rate of 3° C./min to 7° C./min, preferably 4° C./min to 6° C./min, so that the temperature inside the reactor is 30 to 40° C., preferably 33 to 37. The temperature can be raised until it reaches °C.

Next, as a third step of the method for producing a perfluorinated sulfonated ionomer of the present invention, a radical initiator may be introduced into the reactor.

As mentioned above, the radical initiator is a bis (fluoroacyl) peroxide compound, a bis (chlorofluoroacyl) peroxide compound, a dialkyl peroxydicarbonate compound, a diacyl peroxide compound, a peroxy ester compound, It may include at least one selected from perfluoroperoxide-based compounds, azo-based compounds, and persulfate-based compounds, and preferably at least one selected from perfluoroperoxide-based compounds and persulfate-based compounds, and , The radical initiator may be mixed with deionized water and used as a radical initiator solution. In this case, the radical initiator solution may contain 0.1 to 2% by weight of the radical initiator, preferably 0.5 to 1.5% by weight.

In the third step, after introducing a radical initiator into the reactor, heat is applied to the inside of the reactor at a rate of 3°C/min to 7°C/min, preferably 4°C/min to 6°C/min, thereby increasing the temperature inside the reactor. The temperature may be raised to 40 to 60°C, preferably 45 to 55°C, and maintained for 30 to 90 minutes, preferably 45 to 75 minutes.

Next, as a fourth step of the method for producing a perfluorinated sulfonated ionomer of the present invention, a compound including -SO ₂ F group can be prepared by adding and stirring a compound represented by the following formula (2) in the reactor.

[Formula 2]

In this case, the compound represented by Formula 2 may be added in a weight ratio of 0.45 to 1.32, based on 1 weight of the compound represented by Formula 1 introduced in the first step.

Specifically, relative to 1 weight of the compound represented by the following formula 1-1, the compound represented by the formula (2) is 0.45 to 1.32 weight ratio, preferably 0.6 to 1.32 weight ratio, more preferably 0.7 to 1.1 weight ratio, even more preferably It can be added in a weight ratio of 0.71 to 0.85.

[Formula 1-1]

In Formula 1-1, a is 1.

In addition, the compound represented by Formula 2 may be added in a weight ratio of 0.50 to 0.96, preferably 0.52 to 0.80, more preferably 0.53 to 0.62 by weight, relative to 1 weight of the compound represented by Formula 1-2 below.

[Formula 1-2]

In Formula 1-2, a is 2.

On the other hand, when preparing a compound containing -SO ₂ F group through the fourth step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the inside of the reactor is 0.4 to 1.2 MPa, preferably 0.6 to 1.0 MPa, more preferably Preferably, a pressure of 0.7 to 0.9 MPa, a temperature of 40 to 60° C., preferably 45 to 55° C., 150 to 450 rpm, preferably 200 to 400 rpm, more preferably at a stirring speed of 250 to 350 rpm, 1 to It can be carried out for 5 hours, preferably 2 to 4 hours.

Finally, as the fifth step of the method for producing a perfluorine-based sulfonated ionomer of the present invention, the compound containing the -SO ₂ F group prepared in the fourth step is immersed in a solution containing a hydrolyzing agent to contain a sulfonate group. A compound is prepared, and the compound containing the sulfonate group is immersed in a solution containing an oxidizing agent to include a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5) The polymer can be prepared, and preferably a polymer including a repeating unit represented by the following formula (6) can be prepared.

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.

[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, and x, y and z are molar ratios, 1: 0.01 to 1: rational number of 0.01 to 1, preferably 1: 0.05 to 0.3: rational number of 0.025 to 0.1, further Preferably 1: 0.1 to 0.2: 0.045 to 0.075 rational number, even more preferably 1: 0.1 to 0.2: 0.045 to 0.065 rational number, even more preferably 1: 0.1 to 0.15: 0.045 to 0.055 rational number, The order of bonding of each constituent unit according to, x, y and z may be randomly modified.

In addition, the polymer has a weight average molecular weight of 20,000 to 10,000,000, preferably a weight average molecular weight of 30,000 to 8,000,000, more preferably a weight average molecular weight of 50,000 to 1,000,000, even more preferably a weight average molecular weight of 50,000 to 800,000, even more preferably a weight average It may have a molecular weight of 100,000 to 300,000.

Specifically, the fifth step of the method for producing a perfluorine-based sulfonated ionomer of the present invention is to hydrolyze the compound containing the -SO ₂ F group prepared in the fourth step through a hydrolyzing agent to form the -SO ₂ F group as a sulfonate group. It is a process of substituting and replacing the sulfonate group with -SO ₃ H group through an oxidizing agent.

A solution containing a hydrolyzing agent is a substance in which the aforementioned hydrolyzing agent is mixed in a solvent, and a solution containing an oxidizing agent is a substance in which the aforementioned oxidizing agent is mixed in a solvent, and the solvent is water or water and a polar solvent. It may be a mixed solvent. As a polar solvent, alcohol (methanol, ethanol, etc.) or dimethyl sulfoxide may be used.

Meanwhile, referring to FIG. 1, the composite electrolyte membrane for a polymer electrolyte membrane fuel cell (PEMFC) of the present invention includes a support layer 10, a first electrolyte layer 20 formed on one surface of the support layer 10, and the support layer ( 10) It may include a second electrolyte layer 30 formed on the other surface.

Specifically, the first electrolyte layer 20 may be disposed in an anode direction, and the second electrolyte layer 30 may be disposed in a cathode direction.

At this time, at least one of the first electrolyte layer 20 and the second electrolyte layer 30 may include the perfluorine-based sulfonated ionomer of the present invention described above. Specifically, the first electrolyte layer 20 or the second electrolyte layer 30 includes the perfluorine-based sulfonated ionomer of the present invention mentioned above, or the first electrolyte layer 20 and the second electrolyte layer 30 It may contain the perfluorinated sulfonated ionomer of the present invention mentioned above.

In addition, the perfluorine-based sulfonated ionomer of the present invention may not only constitute the first electrolyte layer 20 and/or the second electrolyte layer 30, but may be included in the pores of the support layer 10.

Meanwhile, the first electrolyte layer 20 and/or the second electrolyte layer 30 of the present invention may further include a radical scavenger for PEMFC in addition to the perfluorine-based sulfonated ionomer of the present invention.

The radical scavenger for PEMFC of the present invention is a CeZnO metal oxide having a ZnO crystal structure doped with cerium ions by mixing and reducing an aqueous solution of Ce precursor in a solution containing [Zn(OH) ₄ ] ^2- It can be produced by forming particles. Here, the "Ce ion-doped ZnO crystal structure" means that a crystal structure in which some of the Zn atoms are replaced with Ce atoms in a ZnO crystal structure having a crystal structure such as a Wurtzite is newly formed.

In more detail, after preparing a Zn precursor solution by dissolving a Zn precursor in alcohol, a first step of heating the Zn precursor solution; [Zn(OH) ₄ ] A second step of preparing a ^2- containing solution; [Zn(OH) ₄ ] A third step of forming CeZnO metal oxide particles having a ZnO crystal structure doped with Ce ions by mixing and reducing an aqueous solution of Ce precursor to the ^2- containing solution; A fourth step of recovering and washing the CeZnO metal oxide particles; And a fifth step of drying the washed CeZnO metal oxide particles, thereby manufacturing a radical scavenger for PEMFC. For a more detailed description of this, Korean Patent Registration No. 10-1860870 by the same applicant may be incorporated by reference.

The radical scavenger for PEMFC of the present invention is a metal oxide particle having a crystal structure composed of a cerium (Ce) atom, a zinc (Zn) atom, and an oxygen (O) atom, and as a preferred example, crystals such as Wurtzite In the structured ZnO crystal structure, it may have a crystal structure in which some of the Zn atoms are substituted with Ce atoms.

In addition, the radical scavenger for PEMFC of the present invention may contain 12 to 91% by weight of Ce, 7 to 84.5% by weight of Zn, and the remaining amount of O, preferably 13.40 to 89.20% by weight of Ce, and 7.55 to 88.20 by weight of Zn. % And the balance of O may be included. In addition, other inevitable impurities may be further included.

In addition, the radical scavenger of the present invention may be 200 nm or less, preferably 160 nm or less, more preferably 45 to 160 nm, when analyzing particle size (D50) with a DLS (Dynamic Light Scattering) nanoparticle size analyzer. have.

Further, the first electrolyte layer 20 and/or the second electrolyte layer 30 of the present invention are each independently 0.5 to 1.5 parts by weight of a radical scavenger for PEMFC based on 100 parts by weight of a perfluorine-based sulfonated ionomer, preferably May contain 0.7 to 1.3 parts by weight, more preferably 0.9 to 1.1 parts by weight, and if it is included in less than 0.5 parts by weight, there may be a problem of poor durability, and if it exceeds 1.5 parts by weight, durability is improved, but ion There may be a problem in that the conductivity of the composite electrolyte membrane is deteriorated due to a decrease in conductivity.

In addition, the first electrolyte layer 20 and/or the second electrolyte layer 30 may each independently further include hollow silica.

The hollow silica may have a spherical shape, and an average particle diameter may be 10 to 300 nm, more preferably 10 to 100 nm. Here, the meaning of the particle diameter means the diameter when the shape of the hollow silica is spherical, and when the shape of the hollow silica is not spherical, it means the maximum distance among the linear distances from one point on the surface of the hollow silica to another point.

In addition, the first electrolyte layer 20 and/or the second electrolyte layer 30 may each further include at least one absorbent selected from zeolite, titania, zirconia, and montmorillonite.

In addition, the support layer 10 and the first electrolyte layer 20 of the present invention may have a thickness ratio of 1: 0.8 to 1.2, preferably 1: 0.9 to 1.1.

On the other hand, the support layer 10 of the present invention may use a general porous support used in the art, and preferably may include a PTFE (Polytetrafluoroethylene) porous support having specific physical properties manufactured by the following manufacturing method.

The PTFE porous support of the present invention comprises: a 1-1 step of mixing and stirring a PTFE powder and a lubricant to prepare a paste; A 1-2 step of aging the paste; Step 1-3 of extruding and rolling the aged paste to produce a green tape; After drying the green tape, step 1-4 of removing the liquid lubricant; 1-5 steps of uniaxially stretching the green tape from which the lubricant has been removed; Steps 1-6 of biaxially stretching the uniaxially stretched unfired tape; And it can be produced by performing a process including a 1-7 step of firing.

In step 1-1, the paste may contain 15 to 35 parts by weight of a lubricant, preferably 15 to 30 parts by weight, and more preferably 15 to 25 parts by weight, based on 100 parts by weight of the PTFE powder. If the lubricant is less than 15 parts by weight based on 100 parts by weight of the PTFE powder, the porosity may be lowered when the PTFE porous support is formed by the biaxial stretching process described below, and if it exceeds 35 parts by weight, the pore size when forming the PTFE porous support is It may become larger and the strength of the support may be weakened.

The average particle diameter of the PTFE powder is 300㎛ ~ 800㎛. Preferably, it may be 450 μm to 700 μm, but is not limited thereto. The lubricant is a liquid lubricant, in addition to hydrocarbon oils such as liquid paraffin, naphtha, white oil, toluene, and xylene, various alcohols, ketones, esters, etc. can be used, preferably selected from liquid paraffin, naphtha, and white oil. More than one type can be used.

Next, the aging of step 1-2 is a preforming process, and the paste can be aged for 12 to 24 hours at a temperature of 30°C to 70°C, and preferably 16 to 60°C at a temperature of 35°C to 60°C. It can be aged for 20 hours. When the aging temperature is less than 30° C. or the aging time is less than 12 hours, the lubricant coating becomes non-uniform on the surface of the PTFE powder, and thus, the stretching uniformity of the PTFE porous support may be limited during biaxial stretching, which will be described later.

In addition, when the aging temperature exceeds 70°C or the aging time exceeds 24 hours, there may be a problem in that the pore size of the PTFE porous support after the biaxial stretching process is too small due to evaporation of the lubricant.

Next, in the extrusion of steps 1-3, the aged paste is compressed in a compressor to produce a PTFE block, and the PTFE block is then compressed at a pressure of 0.069 to 0.200 Ton/cm ² , preferably 0.090 to 0.175 Ton/cm. It can be carried out by pressing extrusion at a pressure of ² .

At this time, when the pressure extruding pressure is less than 0.069 Ton/cm ² , the pore size of the porous support may increase and the strength of the porous support may be weakened. If it exceeds 0.200 Ton/cm ² , the pore size of the porous support after the biaxial stretching process There may be a problem of getting smaller.

In addition, the rolling of steps 1-3 may be performed with a hydraulic pressure of 5 to 10 MPa and a calendering process at 50 to 100°C. In this case, when the hydraulic pressure is less than 5 MPa, the pore size of the porous support increases, so that the strength of the porous support may be weakened, and when it exceeds 10 MPa, there may be a problem that the pore size of the porous support decreases.

Next, the drying of steps 1-4 can be performed through a general drying method used in the art, and a preferred example is, for example, an unfired tape manufactured by rolling 1 to 5M/ at a temperature of 100°C to 200°C. While being transferred to a conveyor belt at a speed of min, it can be carried out while being transferred at a rate of 2 to 4M/min, preferably at a temperature of 140°C to 190°C. At this time, when the drying temperature is 100°C or less or the drying rate exceeds 5M/min, bubbles may occur during the stretching process due to non-evaporation of the lubricant, and the drying temperature is 200°C or more or the drying speed is 1M/min. If it is less than min, the stiffness of the dried tape increases, and thus slip may occur during the stretching process.

Next, the uniaxial stretching of steps 1-5 is a process of stretching the unfired tape from which the lubricant has been removed in the longitudinal direction, and when transported through rollers, uniaxial stretching is performed using the difference in speed between the rollers. . And, uniaxial stretching is 3 to 10 times, preferably 6 to 9.5 times, more preferably 6.2 to 9 times, even more preferably 6.3 to 8.2 times in the longitudinal direction of the unfired tape from which the lubricant is removed. Good to do. In this case, if the uniaxial draw ratio is less than 3 times, sufficient mechanical properties cannot be secured, and if the uniaxial draw ratio exceeds 10 times, mechanical properties are rather reduced, and there may be a problem that the pores of the support become too large.

In addition, uniaxial stretching is performed at a stretching temperature of 260°C to 350°C and a stretching speed of 6 to 12 M/min, preferably a stretching temperature of 270°C to 330°C and a stretching speed of 8 to 11.5 M/min. It is better. If the stretching temperature is less than 260℃ during uniaxial stretching, or when the stretching speed is less than 6 M/min, there may be a problem that the sintering section occurs due to increased heat loaded on the drying sheet. When is greater than 350°C or the stretching speed exceeds 12 M/min, slip occurs during the uniaxial stretching process, resulting in a problem of lowering the thickness uniformity.

Next, in the biaxial stretching of steps 1-6, stretching is performed in the width direction of the unfired tape that has been uniaxially stretched (a direction perpendicular to the uniaxial stretching), and the width is widened in the transverse direction while the end is fixed. Can be stretched. However, it is not limited thereto, and may be stretched according to a stretching method commonly used in the art. In the present invention, the biaxial stretching may be performed 15 to 50 times in the width direction, preferably 25 to 45 times, more preferably 28 to 45 times, even more preferably 29 to 42 times. In this case, if the biaxial draw ratio is 15 times or less, sufficient mechanical properties may not be secured, and even if it exceeds 50 times, mechanical properties are not improved, and the uniformity of properties in the longitudinal and/or width directions decreases. Since there may be, it is good to perform stretching within the above range.

In addition, biaxial stretching is performed under a stretching temperature of 150°C to 260°C at a drawing speed of 10 to 20 M/min, and preferably at a drawing temperature of 200°C to 250°C under a drawing speed of 11 to 18 M/min. If the biaxial stretching temperature is less than 150°C or the stretching speed is less than 10 M/min, there may be a problem of lowering the stretching uniformity in the transverse direction, and the biaxial stretching temperature exceeds 260°C, or If the drawing speed exceeds 20 M/min, there may be a problem of deteriorating physical properties due to occurrence of an unfired section.

Finally, the sintering of the first to seventh steps moves the stretched porous support on a conveyor belt at a speed of 10 to 18 M/min, preferably at a speed of 13 to 17 M/min, while at 350°C to 450°C, Preferably, it can be carried out by applying a temperature of 380°C to 440°C, more preferably 400°C to 435°C, through which the draw ratio can be fixed and strength improvement effect can be achieved. During firing, if the firing temperature is less than 350°C, the strength of the porous support may be lowered, and if it exceeds 450°C, there may be a problem in that the physical properties of the support decrease due to a decrease in the number of fibrils due to undercalcination.

In addition, the PTFE porous support manufactured by performing the processes of steps 1-7 has a stretch ratio (or aspect ratio) of 1:3.00 to 8.5, preferably 1 in the uniaxial direction (length direction) and in the biaxial direction (width direction). : 4.0 to 7.0, more preferably 1: 4.00 to 5.50, and even more preferably 1: 4.20 to 5.00, and the stretching ratio (or aspect ratio) in the uniaxial direction and the biaxial direction is higher in the above range It is preferable in terms of mechanical properties, securing an appropriate pore size of the support, and securing an appropriate current flow.

The prepared PTFE porous support of the present invention may have an average pore size of 0.080 μm to 0.200 μm, preferably 0.090 μm to 0.180 μm, more preferably 0.095 μm to 0.150 μm, and even more preferably 0.100 to 0.140 μm. . In addition, the PTFE porous support of the present invention may have an average porosity of 60% to 90%, more preferably 60% to 79.6%.

If the average pore size of the PTFE porous support of the present invention is less than 0.080 μm or the porosity is less than 60%, when impregnating the electrolyte to prepare an electrolyte membrane using a PTFE porous support, the degree of impregnation of the electrolyte in the PTFE porous support may be limited. I can. In addition, when the average pore size exceeds 0.200 µm or the porosity exceeds 90%, the structure of the PTFE porous support is deformed when impregnated with the electrolyte, and the product life may be deteriorated due to a decrease in dimensional stability.

On the other hand, the PTFE porous support of the present invention, when measured according to ASTM D 882, the modulus values in the uniaxial direction and the modulus in the biaxial direction may satisfy Equation 1 below.

[Equation 1]

0 ≤ │(modulus in 1 axis direction-modulus in 2 axis direction)/(modulus in axis 1 direction)×100%│ ≤ 54%, preferably 0 ≤ │(modulus in 1 axis direction-modulus in 2 axis direction)/(1 axis Directional modulus)×100%│ ≤ 40%, more preferably 1 ≤ │(1 axis direction modulus-2 axis direction modulus)/(1 axis direction modulus)×100%│ ≤ 26%

In addition, the PTFE porous support of the present invention may have a uniaxial (longitudinal) modulus of 40 MPa or more, preferably a uniaxial modulus of 50 MPa or more, more preferably, when measured according to ASTM D 882. Preferably, the modulus in the uniaxial direction may be 48 to 75 Mpa, even more preferably 65 to 75 Mpa. In addition, the modulus in the biaxial direction (width direction) is 40 MPa or more, preferably, the modulus in the biaxial direction (width direction) is 55 Mpa or more, more preferably 46 to 75 Mpa, and even more preferably 55 to 75 Mpa. I can.

In addition, when measured according to ASTM D882, the PTFE porous support of the present invention may have a tensile strength of 40 MPa or more in a uniaxial direction (length direction) and a tensile strength of 40 MPa or more in a biaxial direction (width direction), preferably 1 The tensile strength in the axial direction may be 50 MPa or more, and more preferably, the tensile strength in the uniaxial direction may be 54 to 65 Mpa. In addition, preferably, the tensile strength in the biaxial direction may be 52 Mpa or more, and more preferably the tensile strength in the biaxial direction may be 52 to 70 Mpa.

Further, the method of manufacturing a composite electrolyte membrane for PEMFC of the present invention includes the first to fourth steps.

First, in the first step of the method for manufacturing a composite electrolyte membrane for PEMFC of the present invention, a polytetrafluoroethylene (PTFE) porous support may be prepared.

The PTFE porous support prepared in the first step may be the same as the PTFE porous support and method of manufacturing described above.

Next, in the second step of the method for manufacturing a composite electrolyte membrane for PEMFC of the present invention, a first electrolyte layer may be formed on one surface of the PTFE porous support prepared in the first step.

Specifically, the second step is a process of forming a first electrolyte layer on one surface of the PTFE porous support, which is applied to a solution containing the perfluorinated sulfonated ionomer of the present invention on one surface of the PTFE porous support, or on one surface of the PTFE porous support. May be impregnated in a solution containing the perfluorine-based sulfonated ionomer of the present invention and then dried to form a first electrolyte layer.

The drying in the second step may be performed by applying heat of 60°C to 100°C for 1 to 30 minutes, or preferably by applying heat of 70°C to 90°C for 5 to 15 minutes. At this time, if the drying temperature is less than 60°C, the liquid retention properties of the solution containing the perfluorinated sulfonated ionomer of the present invention impregnated into the porous support may be reduced, and if it exceeds 100°C, the electrolyte membrane and/or the membrane-electrode assembly During manufacture, the adhesion to the electrode may be deteriorated.

Next, in the third step of the method for manufacturing a composite electrolyte membrane for PEMFC of the present invention, a second electrolyte layer may be formed on the other surface of the PTFE porous support prepared in the first step.

Specifically, the third step is a process of forming a second electrolyte layer on the other surface of the PTFE porous support on which the first electrolyte layer is formed, and is applied to a solution containing the perfluorine-based sulfonated ionomer of the present invention on the other surface of the PTFE porous support, or , After impregnating the other surface of the PTFE porous support in the solution containing the perfluorine-based sulfonated ionomer of the present invention, and then drying it, a second electrolyte layer may be formed.

The drying of the third step may be performed by applying heat of 60°C to 100°C for 1 to 30 minutes, or preferably by applying heat of 70°C to 90°C for 5 to 15 minutes. At this time, if the drying temperature is less than 60°C, the liquid retention properties of the solution containing the perfluorinated sulfonated ionomer impregnated into the porous support may be deteriorated. The bonding property with may be deteriorated.

Meanwhile, the solution containing the perfluorine-based sulfonated ionomer of the present invention used to form the first and/or second electrolyte layers in the second and third steps is a radical scavenger for PEMFC, a hollow silica, or a desiccant. May be additionally mixed, and each of the perfluorine-based sulfonated ionomer of the present invention, the radical scavenger for PEMFC, the hollow silica and the desiccant is the perfluorine-based sulfonated ionomer of the present invention described above, the radical scavenger for PEMFC, and hollow It may be the same as type silica and desiccant.

Finally, in the fourth step of the method for manufacturing a composite electrolyte membrane for PEMFC of the present invention, a composite electrolyte membrane for PEMFC of the present invention can be prepared by heat-treating the PTFE porous support on which the first and second electrolyte layers are formed.

The heat treatment in the fourth step can be performed at 100°C to 200°C for 1 minute to 5 minutes, preferably at 140°C to 180°C for 1 minute to 5 minutes, and the heat treatment temperature is less than 100°C or the heat treatment time is less than 1 minute On the back side, the liquid retention properties of the first and/or second electrolyte layers may decrease, and when the heat treatment temperature exceeds 200°C, the adhesion (bonding property) between the first and second electrolyte layers and the porous support may decrease. have.

In the PTFE porous support of the composite electrolyte membrane subjected to the heat treatment of the fourth step, the volume of the closed pores may be 85% by volume or more, preferably 90% by volume or more with respect to the total pore volume.

Further, the composite electrolyte membrane for PEMFC of the present invention may have a durability of 1.5 to 10.0 μmol/hr·g, preferably 1.5 to 3.5 μmol/hr·g, and more preferably 1.5 to 2.2 μmol/hr·g.

In addition, the composite electrolyte membrane for PEMFC of the present invention may have an ionic conductivity of 0.07 to 0.2 S/cm, 0.10 to 0.2 S/cm, preferably 0.135 to 0.18 S/cm, more preferably 0.14 to 0.17 S/cm. .

Meanwhile, referring to FIG. 2, the membrane-electrode assembly for PEMFC of the present invention includes an anode (anode) 200, the composite electrolyte membrane 100 and a cathode (reduction electrode) 300 for PEMFC of the present invention mentioned above. Includes.

In other words, the membrane-electrode assembly according to an embodiment of the present invention includes an anode (anode 200) and a cathode (cathode, reduction electrode, 300) positioned opposite to each other with the composite electrolyte membrane 100 interposed therebetween. It is equipped with. In this case, the anode 200 includes an anode gas diffusion layer 3, an anode catalyst layer 2 and an anode electrode substrate 1, and the cathode 300 is a cathode gas diffusion layer 4, a cathode catalyst layer 5, and a cathode. It may include an electrode substrate 6.

Specifically, the anode 200 may be formed by sequentially stacking the anode gas diffusion layer 3, the anode catalyst layer 2, and the anode electrode substrate 1, and the anode gas diffusion layer 3 is a composite electrolyte membrane 200. It may be bonded to one side of. In addition, the cathode 300 may be formed by sequentially stacking the cathode gas diffusion layer 4, the cathode catalyst layer 5, and the cathode electrode substrate 6, and the cathode gas diffusion layer 4 is formed of the composite electrolyte membrane 200. It may be bonded to the other side.

The membrane-electrode assembly of the present invention may be formed by disposing the anode 200, the composite electrolyte membrane 100, and the cathode 300, respectively, and then fastening them, or compressing them at high temperature and high pressure.

The anode gas diffusion layer 3 may be formed by coating a gas diffusion layer forming material on one surface of the composite electrolyte membrane 100.

The anode gas diffusion layer 3 may be provided to prevent rapid diffusion of fuel injected into the fuel cell and to prevent a decrease in ionic conductivity. In addition, the anode gas diffusion layer 3 may control the diffusion rate of fuel through heat treatment or electrochemical treatment. In addition, the anode gas diffusion layer 3 serves as a current conductor between the composite electrolyte membrane 100 for PEMFC and the anode catalyst layer 2, and serves as a passage for gas as a reactant and water as a product. Accordingly, the anode gas diffusion layer 3 may have a porous structure having a porosity of 20% to 90% so that gas can pass therethrough. The thickness of the anode gas diffusion layer 3 may be appropriately adopted as necessary, and may be, for example, 100 to 400 μm. When the thickness of the anode gas diffusion layer 3 is less than 100 μm, electrical contact resistance between the anode catalyst layer 2 and the anode electrode substrate 1 increases, and the structure may become unstable due to compression. In addition, when the thickness of the anode gas diffusion layer 3 exceeds 400 μm, it may be difficult to move the gas as a reactant.

In addition, the anode gas diffusion layer 3 may be formed of a carbon-based material and a fluorine-based resin. Carbon-based materials include graphite, carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nanowire, fullerene (C60) And it may include one or more selected from the group consisting of super P, but is not limited thereto. In addition, as a fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), polyvinyl alcohol, cellulose acetate, polyvinylidene fluoride-hexafluoropropylene copolymer, or styrene-butadiene high moiety (SBR) It may include one or more selected from the group consisting of. Further, the fuel may be a liquid fuel such as formic acid solution, methanol, formaldehyde, or ethanol.

The anode catalyst layer 2 is a layer into which an oxidation catalyst is introduced, and the anode catalyst layer 2 may be formed by applying a catalyst layer forming material on the anode gas diffusion layer 3.

The catalyst layer forming material may be a metal catalyst or a metal catalyst supported on a carbon-based support. As the metal catalyst, at least one selected from the group consisting of platinum, ruthenium, platinum-ruthenium alloy, platinum-osmium alloy, platinum-palladium alloy, and platinum-transition metal alloy may be used. In addition, as the carbon-based support, graphite (graphite), carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nano It may include at least one selected from the group consisting of wire, fullerene, and super P.

In addition, the anode catalyst layer 2 may include a conductive support and an ion conductive binder (not shown). In addition, the anode catalyst layer 2 may include a main catalyst attached to a conductive support. The conductive support may be carbon black, and the ion conductive binder may be a Nafion ionomer or a sulfonated polymer. In addition, the main catalyst may be a metal catalyst, and as an example, may be platinum (Pt). The anode catalyst layer 2 can be formed using an electroplating method, a spray method, a painting method, a doctor blade method, or a transfer method.

The anode electrode substrate 1 may be a conductive substrate selected from the group consisting of carbon paper, carbon cloth, and carbon felt, but is not limited thereto, and any anode electrode material applicable to a polymer electrolyte fuel cell may be used. It is possible. The anode electrode substrate 1 may be formed on one surface of the anode catalyst layer 2 through a conventional deposition method, and after forming the anode catalyst layer 2 on the anode electrode substrate 1, the anode gas diffusion layer 3 ) On the anode catalyst layer 2 and the anode electrode substrate 1 may be formed to be in contact with each other.

The cathode gas diffusion layer 4 may be formed by applying a gas diffusion layer forming material to the other surface of the composite electrolyte membrane 100.

The cathode gas diffusion layer 4 may be provided to prevent rapid diffusion of gas injected into the cathode 300 and uniformly disperse the gas injected into the cathode 300. In addition, the cathode gas diffusion layer 4 serves as a current conductor between the PEMFC composite electrolyte membrane 100 and the cathode catalyst layer 5, and serves as a passage for gas as a reactant and water as a product. Accordingly, the cathode gas diffusion layer 4 may have a porous structure having a porosity of 20% to 90% to allow gas to pass therethrough. The thickness of the cathode gas diffusion layer 4 may be appropriately adopted as needed, and may be, for example, 100 to 400 μm. When the thickness of the cathode gas diffusion layer 4 is 100 μm or less, electrical contact resistance between the cathode catalyst layer 5 and the cathode electrode substrate 6 increases, and the structure may become unstable due to compression. In addition, when the thickness of the cathode gas diffusion layer 4 exceeds 400 μm, it may be difficult to move the gas as a reactant.

In addition, the cathode gas diffusion layer 4 may be formed of a carbon-based material and a fluorine-based resin. Carbon-based materials include graphite, carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nanowire, fullerene (C60) And it may include one or more selected from the group consisting of super P, but is not limited thereto. In addition, as a fluorine-based resin, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), polyvinyl alcohol, cellulose acetate, polyvinylidene fluoride-hexafluoropropylene copolymer, or styrene-butadiene high moiety (SBR) It may include one or more selected from the group consisting of. Further, the fuel may be a liquid fuel such as formic acid solution, methanol, formaldehyde, or ethanol.

The cathode catalyst layer 5 is a layer into which a reduction catalyst is introduced, and the cathode catalyst layer 5 may be formed by coating a catalyst layer forming material on the cathode gas diffusion layer 4

The catalyst layer forming material may be a metal catalyst or a metal catalyst supported on a carbon-based support. As the metal catalyst, at least one selected from the group consisting of platinum, ruthenium, platinum-ruthenium alloy, platinum-osmium alloy, platinum-palladium alloy, and platinum-transition metal alloy may be used. In addition, as the carbon-based support, graphite (graphite), carbon black, acetylene black, denka black, kecheon black, activated carbon, mesoporous carbon, carbon nanotube, carbon nanofiber, carbon nanohorn, carbon nanoring, carbon nano It may include at least one selected from the group consisting of wire, fullerene, and super P.

In addition, the cathode catalyst layer 5 may include a conductive support and an ion conductive binder (not shown). In addition, the cathode catalyst layer 5 may include a main catalyst attached to the conductive support. The conductive support may be carbon black, and the ion conductive binder may be a Nafion ionomer or a sulfonated polymer. In addition, the main catalyst may be a metal catalyst, and as an example, may be platinum (Pt). The cathode catalyst layer 5 may be formed using an electroplating method, a spray method, a painting method, a doctor blade method, or a transfer method.

The cathode electrode substrate 6 may be a conductive substrate selected from the group consisting of carbon paper, carbon cloth, and carbon felt, but is not limited thereto, and any cathode electrode material applicable to a polymer electrolyte fuel cell may be used. It is possible. The cathode electrode substrate 6 may be formed on one surface of the cathode catalyst layer 5 through a conventional vapor deposition method, and after forming the cathode catalyst layer 5 on the cathode electrode substrate 6, the cathode gas diffusion layer 4 ) May be formed by placing the cathode catalyst layer 5 and the cathode electrode substrate 6 in contact with each other.

Furthermore, the membrane-electrode assembly for PEMFC of the present invention has a hydrogen permeability of 1.0 to 2.6 mA/cm², preferably a hydrogen permeability of 1.5 to 2.5 mA/cm², more preferably a hydrogen permeability of 2.0 to 2.3 mA/cm². I can.

Meanwhile, in the polymer electrolyte membrane fuel cell according to an embodiment of the present invention, at least one electricity generation unit for generating electric energy through an oxidation reaction of fuel and a reduction reaction of an oxidizing agent, and the above-described fuel are supplied to the electricity generation unit. And an oxidizing agent void for supplying an oxidizing agent to the electricity generating unit.

Including at least one membrane-electrode assembly of the present invention, separators for supplying fuel and an oxidizing agent are disposed at both ends of the membrane-electrode assembly of the present invention to constitute an electricity generating unit. At least one of these electric generating units may be gathered to form a stack.

At this time, the arrangement form or manufacturing method of the polymer electrolyte membrane fuel cell of the present invention can be formed without limitation as long as it is applicable to the polymer electrolyte fuel cell, and thus may be variously applied with reference to the prior art.

The embodiments of the present invention have been described above, but these are only examples and do not limit the embodiments of the present invention, and those of ordinary skill in the field to which the embodiments of the present invention pertain are not limited to the essential characteristics of the present invention. It will be appreciated that various modifications and applications not illustrated above are possible within the range not departing from. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

[Example]

Example 1: Preparation of perfluorinated sulfonated ionomer

(1) 500 ml of deionized water, 35 g of a compound represented by the following formula 1-1, and 26 g of a compound represented by the following formula 2 were added to a 1 L stainless steel autoclave, and stirred at a speed of 300 rpm for 30 minutes.

[Formula 1-1]

[Formula 2]

After stirring, the inside of the autoclave can be vacuumed to remove moisture, and the process of purging again with nitrogen gas was performed three times.

(2) Tetrafluoroethylene (TFE) gas was introduced into the autoclave, and the interior of the autoclave was replaced with a TFE gas atmosphere having a pressure of 0.01 MPa. After substitution, the inside of the autoclave was vacuumed to remove moisture, and TFE gas was introduced into the autoclave until the pressure inside the autoclave reached 0.8 MPa. Thereafter, heat was applied to the interior of the autoclave at a rate of 5°C/min, and the temperature was increased until the temperature inside the autoclave reached 35°C.

(3) A solution containing a radical initiator (a solution containing 1% by weight of potassium persulfate (KPS) as a radical initiator in deionized water) in the autoclave was divided 7 times for 30 minutes, and 500 ppm was added. Thereafter, heat was applied to the inside of the autoclave at a rate of 5°C/min, the temperature inside the reactor was raised to 50°C, and the reaction was carried out for 3 hours to prepare a compound containing -SO ₂ F. . The prepared -SO ₂ F group-containing compound was washed with water 3 times using 5 L of distilled water.

(4) Hydrolysis is performed by immersing the washed compound containing the -SO ₂ F group in a solution containing a hydrolysis agent (aqueous solution containing potassium hydroxide), and a solution containing an oxidizing agent (aqueous solution containing hydrochloric acid) ) To prepare a perfluorine-based sulfonated ionomer containing a polymer represented by a repeating unit represented by the following Formula 6-1. The weight average molecular weight of the prepared perfluorine-based sulfonated ionomer and the chemical equivalent of -SO ₃ H group are shown in Table 1 below.

[Formula 6-1]

In Formula 6-1, x, y, and z are molar ratios, and are rational numbers of 1:0.125:0.05.

Examples 2 to 7

In the same way as in Example 1 A perfluorinated sulfonated ionomer was prepared. However, as described in Table 1 below, the perfluorine-based sulfonated ionomers of Examples 2 to 7 were prepared by varying the content of the components used.

Example 8

In the same way as in Example 1 A perfluorinated sulfonated ionomer was prepared. However, a perfluorine-based sulfonated ionomer including a polymer represented by a repeating unit represented by the following Formula 6-2 was prepared by using a compound represented by the following Formula 1-2 instead of the compound represented by Formula 1-1. The weight average molecular weight of the prepared perfluorinated sulfonated ionomer, the chemical equivalent of the -SO ₃ H group, and the contents of the components used are shown in Table 2 below.

[Formula 1-2]

[Chemical Formula 6-2]

In Formula 6-2, x, y, and z are molar ratios, and are rational numbers of 1:0.146:0.05.

Examples 9 to 12

In the same way as in Example 8 A perfluorinated sulfonated ionomer was prepared. However, as shown in Table 2 below, the perfluorinated sulfonated ionomers of Examples 9 to 12 were prepared by varying the content of the components used.

Comparative Example 1: Preparation of perfluorinated sulfonated ionomer

(1) 500 ml of deionized water and 65 g of a compound represented by the following formula 1-1 were added to a 1 L stainless steel autoclave, and stirred at a speed of 300 rpm for 30 minutes.

[Formula 1-1]

After stirring, the inside of the autoclave can be vacuumed to remove moisture, and the process of purging again with nitrogen gas was performed three times.

(2) Tetrafluoroethylene (TFE) gas was introduced into the autoclave, and the interior of the autoclave was replaced with a TFE gas atmosphere having a pressure of 0.01 MPa. After substitution, the inside of the autoclave was vacuumed to remove moisture, and TFE gas was introduced into the autoclave until the pressure inside the autoclave reached 0.8 MPa. Thereafter, heat was applied to the interior of the autoclave at a rate of 5°C/min, and the temperature was increased until the temperature inside the autoclave reached 35°C.

(3) A solution containing a radical initiator (a solution containing 1% by weight of potassium persulfate (KPS) as a radical initiator in deionized water) in the autoclave was divided 7 times for 30 minutes, and 500 ppm was added. Thereafter, heat was applied to the inside of the autoclave at a rate of 5°C/min, the temperature inside the reactor was raised to 50°C, and the reaction was carried out for 3 hours to prepare a compound containing -SO ₂ F. . The prepared -SO ₂ F group-containing compound was washed with water 3 times using 5 L of distilled water.

(4) Hydrolysis is performed by immersing the washed compound containing the -SO ₂ F group in a solution containing a hydrolysis agent (aqueous solution containing potassium hydroxide), and a solution containing an oxidizing agent (aqueous solution containing hydrochloric acid) ) To prepare a perfluorinated sulfonated ionomer. The weight average molecular weight of the prepared perfluorinated sulfonated ionomer is 124,660, and the chemical equivalent of -SO ₃ H group is 709.

Comparative Example 2

In the same way as in Comparative Example 1 A perfluorinated sulfonated ionomer was prepared. However, instead of the compound represented by Formula 1-1, 89g of the compound represented by Formula 1-2 was used to prepare a perfluorine-based sulfonated ionomer. The weight average molecular weight of the prepared perfluorinated sulfonated ionomer is 134,320, and the chemical equivalent of -SO ₃ H group is 701.

[Formula 1-2]

Comparative Example 3: Preparation of perfluorinated sulfonated ionomer

(1) 500 ml of deionized water and 56 g of a compound represented by the following formula (2) were added to a 1 L stainless steel autoclave, followed by stirring at a speed of 300 rpm for 30 minutes.

[Formula 2]

After stirring, the inside of the autoclave can be vacuumed to remove moisture, and the process of purging again with nitrogen gas was performed three times.

(2) Tetrafluoroethylene (TFE) gas was introduced into the autoclave, and the interior of the autoclave was replaced with a TFE gas atmosphere having a pressure of 0.01 MPa. After substitution, the inside of the autoclave was vacuumed to remove moisture, and TFE gas was introduced into the autoclave until the pressure inside the autoclave reached 0.8 MPa. Thereafter, heat was applied to the interior of the autoclave at a rate of 5°C/min, and the temperature was increased until the temperature inside the autoclave reached 35°C.

(3) A solution containing a radical initiator (a solution containing 1% by weight of potassium persulfate (KPS) as a radical initiator in deionized water) in the autoclave was divided 7 times for 30 minutes, and 500 ppm was added. Thereafter, heat was applied to the inside of the autoclave at a rate of 5°C/min, the temperature inside the reactor was raised to 50°C, and the reaction was carried out for 3 hours to prepare a compound containing -SO ₂ F. . The prepared -SO ₂ F group-containing compound was washed with water 3 times using 5 L of distilled water.

(4) Hydrolysis is performed by immersing the washed compound containing the -SO ₂ F group in a solution containing a hydrolysis agent (aqueous solution containing potassium hydroxide), and a solution containing an oxidizing agent (aqueous solution containing hydrochloric acid) ) To prepare a perfluorinated sulfonated ionomer. The weight average molecular weight of the prepared perfluorinated sulfonated ionomer is 150,650, and the chemical equivalent of -SO ₃ H group is 710.

Preparation Example 1: Preparation of PTFE porous support

A paste was prepared by mixing and stirring 23 parts by weight of naphtha, a liquid lubricant, to 100 parts by weight of PTFE fine powder having an average particle diameter of 570 μm, and uniformly dispersing it.

Next, the paste was allowed to stand at 50° C. for 18 hours to be aged, and then compressed using a molding jig to prepare a PTFE block.

Next, after the PTFE block was put into an extrusion mold, pressure extrusion was performed under a pressure of about 0.10 Ton/cm ² .

Next, using a rolling roll, it was rolled to prepare a green tape having an average thickness of 850 μm.

Next, the unfired tape was transferred to a conveyor belt at a rate of 3 M/min and dried by applying heat at 180° C. to remove the lubricant.

Next, the unfired tape from which the lubricant was removed was uniaxially stretched (lengthwise stretched) by 6.5 times under the conditions of a stretching temperature of 280°C and a stretching speed of 10 M/min.

Next, the uniaxially stretched unfired tape was biaxially stretched 30 times (widthwise stretching) under conditions of a stretching temperature of 250°C and a stretching speed of 10 M/min to prepare a porous support.

Next, uniaxially and biaxially stretched porous supports were fired on a conveyor belt at 420°C at a rate of 15 M/min to prepare a PTFE porous support having an average thickness of 5 μm and an average pore size of 0.114 μm.

Preparation Example 1: Preparation of composite electrolyte membrane for PEMFC

(1) The PTFE porous support prepared in Preparation Example 1 was prepared.

(2) A perfluorine-based sulfonated ionomer solution was prepared by mixing 1 part by weight of a PEMFC radical scavenger (Sang-Afrontech, CeZnO metal oxide) with respect to 100 parts by weight of the perfluorine-based sulfonated ionomer prepared in Example 1.

(3) The PTFE porous support prepared in Preparation Example 1 was fixed to a glass substrate, and one surface of the PTFE porous support was impregnated with a perfluorine-based sulfonated ionomer solution using an applicator. Next, the PTFE porous support impregnated with the perfluorine-based sulfonated ionomer solution was put into a vacuum oven at 80° C. and dried for 10 minutes to form a first electrolyte layer on one side of the PTFE porous support.

The first electrolyte layer is a layer formed by a perfluorine-based sulfonated ionomer solution.

(4) Using an applicator, the other surface of the PTFE porous support on which the first electrolyte layer was formed was impregnated with a perfluorine-based sulfonated ionomer solution. Next, the PTFE porous support impregnated with the perfluorine-based sulfonated ionomer solution was put into a vacuum oven at 80° C. and dried for 10 minutes to form a second electrolyte layer on the other surface of the PTFE porous support. The second electrolyte layer is a layer formed by a perfluorine-based sulfonated ionomer solution.

(5) The PTFE porous support on which the first and second electrolyte layers were formed was heat-treated at 160° C. for 3 minutes to prepare a composite electrolyte membrane for PEMFC. The first electrolyte layer had an average thickness of 5 μm, and the second electrolyte layer was The average thickness was formed to 5 μm.

Preparation Examples 2 to 12 and Comparative Preparation Examples 1 to 3

A composite electrolyte membrane for PEMFC was prepared in the same manner as in Preparation Example 1, but in Preparation Example 2, a composite electrolyte for PEMFC using the perfluorine-based sulfonated ionomer prepared in Example 2 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A membrane was prepared, and in Preparation Example 3, a composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Example 3 instead of the perfluorine-based sulfonated ionomer prepared in Example 1, and Preparation Example 4 was performed in Example 1. A composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Example 4 instead of the prepared perfluorine-based sulfonated ionomer, and in Example 5 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A composite electrolyte membrane for PEMFC was prepared using the prepared perfluorine-based sulfonated ionomer, and Preparation Example 6 was for PEMFC by using the perfluorine-based sulfonated ionomer prepared in Example 6 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A composite electrolyte membrane was prepared, and in Preparation Example 7 a composite electrolyte membrane for PEMFC was prepared by using the perfluorine-based sulfonated ionomer prepared in Example 7 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Example 8 instead of the perfluorine-based sulfonated ionomer prepared in 1, and Preparation Example 9 was an Example instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in 9, and Preparation Example 10 used the perfluorine-based sulfonated ionomer prepared in Example 10 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. A composite electrolyte membrane for PEMFC was prepared, and in Preparation Example 11, a composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Example 11 instead of the perfluorine-based sulfonated ionomer prepared in Example 1, and Preparation Example 12 Example instead of the perfluorinated sulfonated ionomer prepared in Example 1 A composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in 12, and Comparative Preparation Example 1 used the perfluorine-based sulfonated ionomer prepared in Comparative Example 1 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. Thus, a composite electrolyte membrane for PEMFC was prepared, and in Comparative Preparation Example 2, a composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Comparative Example 2 instead of the perfluorine-based sulfonated ionomer prepared in Example 1. In Example 3, a composite electrolyte membrane for PEMFC was prepared using the perfluorine-based sulfonated ionomer prepared in Comparative Example 3 instead of the perfluorine-based sulfonated ionomer prepared in Example 1.

Experimental Example 1: Durability and ionic conductivity measurement experiment of PEMFC composite electrolyte membrane

1) Fenton test

Each of the composite electrolyte membranes for PEMFC prepared in Preparation Examples 1 to 12 and Comparative Preparation Examples 1 to 3 was prepared in a size of 5 cm x 5 cm (width x height), and the mass was dried in an oven at 80° C. for 5 hours or longer. Measure. The prepared specimen was immersed in 200 g of a solution prepared by adding 3 ppm Fe ²⁺ to 2% hydrogen peroxide and left at 80° C. for 120 hours. The fluorine ion concentration eluted from the test piece was measured using a fluorine ion selective electrode, and the results are shown in Tables 3 and 4 below. In the Fenton test, the lower the measured value, the lower the elution of fluorine ions, that is, the superior durability of the electrolyte membrane.

2) Ion conductivity measurement

Each of the PEMFC composite electrolyte membranes prepared in Preparation Examples 1 to 12 and Comparative Preparation Examples 1 to 3 was prepared in a size of 1 cm x 5 cm (width x length), immersed in distilled water, and immersed in an oven at 80° C. for 5 hours. The connected cell was immersed in distilled water, and the impedance was measured after setting the temperature at 25°C, and the ionic conductivity was calculated, and the results are shown in Tables 3 and 4 below.

Experimental Example 2: Water content measurement experiment of composite electrolyte membrane for PEMFC

The composite electrolyte membranes for PEMFC prepared in Preparation Examples 1 to 12 and Comparative Preparation Examples 1 to 2 were completely dried at 120°C for 1 hour, and then the weight (W _d ) was measured. This was again immersed in deionized water and left for 5 hours at 60 to 120°C, and then the sample was taken out, and the water was removed from the surface to measure the weight (W _w ).

Thereafter, the moisture content was measured according to Equation 1 below, and the results are shown in Tables 3 and 4 below.

[Equation 1]

Moisture content (%) = ((W _w -W _d )/W _w ))*100

Experimental Example 3: Hydrogen permeability measurement experiment of PEMFC composite electrolyte membrane

A membrane-electrode assembly for PEMFC having an electrode active area of 25 cm ² each including the composite electrolyte membrane for PEMFC prepared in Preparation Examples 1 to 12 and Comparative Preparation Examples 1 to 2 was prepared and measured at a cell station under RH 100% condition, Initial activation was performed to realize the optimum performance by activating the performance of the PEMFC membrane-electrode assembly. After that, to check the performance of the PEMFC membrane-electrode assembly, the performance of the PEMFC membrane-electrode assembly is performed under the condition of waiting for OCV for 1 minute in CC (Constant Current) mode and repeating each section for 1 minute from 0A to 45A. Measured. Finally, in order to measure the hydrogen permeability, the temperature was set at 80℃ and the RH value was 100%, and H ₂ and N ₂ gas were flowed through the anode to float the 0.4V to 0.5V section. It measured by (plotting), and the results are shown in Tables 3 and 4 below.

As can be seen in Table 3, the composite electrolyte membrane for PEMFC prepared in Preparation Examples 1 to 3 is superior to the composite electrolyte membrane for PEMFC prepared in Preparation Examples 4 to 7 and Comparative Preparation Examples 1 and 3, as well as ionic It was confirmed that the conductivity was high and the hydrogen permeability was low.

Specifically, compared with the composite electrolyte membrane for PEMFC prepared in Preparation Examples 1 to 3, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Preparation Examples 4 to 5 was poor in durability and increased hydrogen permeability.

Also, Compared with the composite electrolyte membrane for PEMFC prepared in Preparation Examples 1 to 3, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Preparation Examples 6 to 7 decreased ionic conductivity and increased hydrogen permeability.

Also, Compared with the composite electrolyte membrane for PEMFC prepared in Preparation Examples 1 to 3, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Comparative Preparation Examples 1 and 3 was poor in durability, decreased ionic conductivity, and increased hydrogen permeability. there was.

As can be seen in Table 4, the composite electrolyte membrane for PEMFC prepared in Preparation Example 8 is superior to the composite electrolyte membrane for PEMFC prepared in Preparation Examples 9 to 12 and Comparative Preparation Examples 2 to 3, as well as ionic conductivity. It was confirmed that it was high and the hydrogen permeability was high.

Specifically, compared with the composite electrolyte membrane for PEMFC prepared in Preparation Example 8, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Preparation Examples 9 to 10 was poor in durability and increased hydrogen permeability.

Also, Compared with the composite electrolyte membrane for PEMFC prepared in Preparation Example 8, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Preparation Examples 11 to 12 was not only deteriorated in durability, but also decreased ionic conductivity and increased hydrogen permeability.

Also, Compared with the composite electrolyte membrane for PEMFC prepared in Preparation Example 8, it was confirmed that the composite electrolyte membrane for PEMFC prepared in Comparative Preparation Examples 2 and 3 significantly worsened the durability, significantly lowered the ionic conductivity, and significantly increased the hydrogen permeability. Could

A simple modification or change of the present invention can be easily implemented by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (17)

Tetrafluoroethylene (TFE); A compound represented by the following formula 1-1; A compound represented by the following formula (2); And radical initiators; Including,
A composition for producing a perfluorine-based sulfonated ionomer, comprising a compound represented by the following Formula 1-1 and a compound represented by the following Formula 2 in a weight ratio of 1:0.7 to 1.1.
[Formula 1-1]

[Formula 2]

The method of claim 1,
The radical initiator is a bis (fluoroacyl) peroxide compound, a bis (chlorofluoroacyl) peroxide compound, a dialkyl peroxydicarbonate compound, a diacyl peroxide compound, a peroxy ester compound, an azo compound And a perfluorine-based sulfonated ionomer comprising at least one selected from persulfate-based compounds.
The method of claim 1,
The composition comprises a hydrolyzing agent; And an oxidizing agent; A composition for producing a perfluorine-based sulfonated ionomer further comprising a.
delete Tetrafluoroethylene (TFE); A compound represented by the following formula 1-2; A compound represented by the following formula (2); And radical initiators; Including,
A composition for producing a perfluorine-based sulfonated ionomer comprising a compound represented by the following Formula 1-2 and a compound represented by the following Formula 2 in a weight ratio of 1: 0.52 to 0.80.
[Formula 1-2]

[Formula 2]

Including a polymer comprising a repeating unit represented by the following formula (3), a repeating unit represented by the following formula (4), and a repeating unit represented by the following formula (5),
The polymer comprises a repeating unit represented by the following formula (6), wherein the polymer has a weight average molecular weight of 50,000 to 800,000 perfluorinated sulfonated ionomer;
[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.
[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are molar ratios, and are rational numbers of 1: 0.05 to 0.3: 0.045 to 0.075, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified.
delete The method of claim 6,
The polymer is a perfluorine-based sulfonated ionomer, characterized in that the chemical equivalent (EW: equivalent weight) of the -SO ₃ H group is 500 to 1200.
Support layer;
A first electrolyte layer formed on one surface of the support layer; And
A second electrolyte layer formed on the other surface of the support layer; Including,
A composite electrolyte membrane for PEMFC, comprising the perfluorine-based sulfonated ionomer of claim 6 in at least one of the first and second electrolyte layers.
The method of claim 9,
The composite electrolyte membrane has a durability measured by a Fenton test of 1.5 to 10 μmol/hr·g, and an ionic conductivity of 0.07 to 0.2 S/cm.
Anode (anode); The composite electrolyte membrane for PEMFC of claim 9; And a cathode (reduction electrode); PEMFC membrane-electrode assembly comprising a.
The method of claim 11,
The membrane-electrode assembly is a membrane-electrode assembly for PEMFC, characterized in that the hydrogen permeability is 1.0 ~ 2.6 mA/cm².
An electricity generator comprising the membrane-electrode assembly and separator for PEMFC of claim 11, and generating electricity through an electrochemical reaction between fuel and an oxidizing agent;
A fuel supply unit supplying fuel to the electricity generation unit; And
An oxidizing agent supply unit supplying an oxidizing agent to the electricity generating unit; Polymer electrolyte membrane fuel cell comprising a.
A first step of introducing and stirring deionized water, a compound represented by the following Formula 1, and a compound represented by the following Formula 2 into the reactor;
A second step of injecting tetrafluoroethylene (TFE) gas into the reactor to replace the internal atmosphere of the reactor with a TFE gas atmosphere;
A third step of preparing a compound containing a -SO ₂ F group by introducing a radical initiator into the reactor; And
The compound containing the -SO ₂ F group is immersed in a solution containing a hydrolyzing agent to prepare a compound containing a sulfonic acid group, and the compound containing the sulfonic acid group is immersed in a solution containing an oxidizing agent to formula 3 A fourth step of preparing a polymer including a repeating unit represented by the following formula (4), a repeating unit represented by the following formula (5); Including,
The polymer comprises a repeating unit represented by the following formula (6), and the polymer has a weight average molecular weight of 50,000 to 800,000; a method for producing a perfluorine-based sulfonated ionomer;
[Formula 1]

In Formula 1, a is 1 or 2.
[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.
[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are molar ratios, and are rational numbers of 1: 0.05 to 0.3: 0.045 to 0.075, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified.
delete A first step of introducing and stirring deionized water and a compound represented by the following formula (1) into the reactor;
A second step of injecting tetrafluoroethylene (TFE) gas into the reactor to replace the internal atmosphere of the reactor with a TFE gas atmosphere;
A third step of introducing a radical initiator into the reactor;
A fourth step of preparing a compound containing a -SO ₂ F group by introducing and stirring a compound represented by the following formula (2) into the reactor; And
The compound containing the -SO ₂ F group is immersed in a solution containing a hydrolyzing agent to prepare a compound containing a sulfonic acid group, and the compound containing the sulfonic acid group is immersed in a solution containing an oxidizing agent to formula 3 A fifth step of preparing a polymer including a repeating unit represented by the following formula (4), a repeating unit represented by the following formula (5); Including,
The polymer comprises a repeating unit represented by the following formula (6), and the polymer has a weight average molecular weight of 50,000 to 800,000; a method for producing a perfluorine-based sulfonated ionomer;
[Formula 1]

In Formula 1, a is 1 or 2.
[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, a is 1 or 2.
[Formula 5]

[Formula 6]

In Formula 6, a is 1 or 2, x, y, and z are molar ratios, and are rational numbers of 1: 0.05 to 0.3: 0.045 to 0.075, and the order of bonding of each constituent unit according to x, y and z is Can be randomly modified. delete

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