KR20220048254A - Reinforced composite meebrane for fuel cells and manufacturing method for the same - Google Patents

Abstract

The present invention relates to a reinforced composite membrane for a fuel cell and a method for manufacturing the same. The reinforced composite membrane for a fuel cell according to an embodiment of the present invention includes: a support; perfluorinated sulfonic acid (PFSA) ionomers disposed in the pores of the support; and hydrocarbon-based nonionic surfactants disposed in the pores of the support.

Description

Reinforced composite meebrane for fuel cells and manufacturing method for the same

The present invention relates to a reinforced composite membrane for a fuel cell and a method for manufacturing the same.

A fuel cell is a power generation device that generates electricity by electrochemically converting fuel supplied from the outside, unlike a secondary battery that undergoes a long charging process. Recently, interest in fuel cells with high energy efficiency and low emission of environmental pollutants due to depletion of petroleum resources and environmental pollution caused by excessive use of fossil fuels is increasing.

Such a fuel cell is composed of an anode, a cathode, and an electrolyte membrane that separates the anode and the cathode to move only specific ions. Perfluorinated sulfonic acid ionomer (PFSA ionomer) is used as a polymer electrolyte membrane material for a polymer electrolyte fuel cell. Such perfluorinated sulfonated ionomers include Nafion manufactured by Dupont, Aquivion manufactured by Solvay, and products from 3M. However, such perfluorinated sulfonated ionomers are expensive and have problems such as delamination.

Korean Patent Publication No. 10-2020-0033630

An object of the present invention is to provide a reinforced composite membrane for a fuel cell excellent in ion conductivity and a method for manufacturing the same.

In addition, it has excellent mechanical properties and dimensional stability.

In addition, it is possible to reduce the manufacturing cost.

A method for manufacturing a reinforced composite membrane for a fuel cell according to an embodiment of the present invention includes preparing a mixed solution by mixing a perfluorinated sulfonated ionomer solution and a hydrocarbon-based nonionic surfactant; and impregnating the support with the mixed solution.

The hydrocarbon-based nonionic surfactant may include at least one of 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol and nonyl phenoxypolyethoxylethanol.

The content of the hydrocarbon-based nonionic surfactant may be 0.5 to 5 parts by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution.

When the hydrocarbon-based nonionic surfactant is 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol, the content of the hydrocarbon-based nonionic surfactant is the perfluorinated sulfonated ionomer solution It may be 1 to 2 parts by weight based on 100 parts by weight.

When the hydrocarbon-based nonionic surfactant is nonyl phenoxypolyethoxylethanol, the content of the hydrocarbon-based nonionic surfactant may be 0.1 to 1 part by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution.

After the step of impregnating the mixed solution in the support, the step of dissolving the surfactant may be further included.

The reinforced composite membrane for a fuel cell according to an embodiment of the present invention is manufactured by the manufacturing method described above.

The reinforced composite membrane for a fuel cell according to an embodiment of the present invention and the reinforced composite membrane manufactured by the method for manufacturing the same have excellent ion conductivity.

In addition, it has excellent mechanical properties and dimensional stability.

In addition, it is possible to reduce the manufacturing cost.

1 and 2 show the FT IR analysis results of Examples 1 to 12 and Comparative Example 1.
3 and 4 show the proton conductivity analysis results of Examples 1 to 12 and Comparative Example 1.
5 and 6 show the moisture content analysis results of Examples 1 to 12 and Comparative Example 1.
7 shows the results of thermal gravimetric analysis.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

Manufacturing method of reinforced composite membrane for fuel cell

A method for manufacturing a reinforced composite membrane for a fuel cell according to an embodiment of the present invention includes preparing a mixed solution by mixing a perfluorinated sulfonated ionomer solution and a hydrocarbon-based nonionic surfactant; and impregnating the support with the mixed solution.

After impregnating the support with the mixed solution, a step of drying the mixed solution may be performed, and then the dried mixture may be immersed in distilled water.

In addition, after the step of impregnating the mixed solution in the support, the step of dissolving the surfactant may be further included, and this step may be performed after the drying and immersion steps described above.

After the impregnating step, a step of removing impurities in the impregnated mixture may be further performed, and then washing and drying may be performed.

The perfluorinated sulfonic acid ionomer (PFSA ionomer) is a material having hydrogen ion conductivity and allows hydrogen ions to selectively pass through the reinforced composite membrane. The perfluorinated sulfonated ionomer is not particularly limited as long as it is used as a hydrogen ion conductive material in the field of fuel cells. When preparing the reinforced composite membrane, the perfluorinated sulfonated ionomer may be in a solution state. Preferably, the perfluorinated sulfonated ionomer solution may be any one of Nafion, Flemion, Aquivion, 3M FSA ionomer, and Aciplex.

The hydrocarbon-based nonionic surfactant performs a function of evenly dispersing the perfluorinated sulfonated ionomer in a mixed solution state, thereby stably and uniformly impregnating the perfluorinated sulfonated ionomer into the pores of the support. . The hydrocarbon-based nonionic surfactant facilitates the wetting process between the hydrophobic support (particularly, PTFE) and the hydrophilic polar solvent, and between the hydrophobic portion of the perfluorinated sulfonated ionomer and the hydrophilic polar solvent. By reducing the surface tension of the perfluorinated sulfonated ionomer can be effectively impregnated.

The hydrocarbon-based nonionic surfactant may include at least one of 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol and nonyl phenoxypolyethoxylethanol. Nonyl phenoxypolyethoxylethanol has a lower critical micelle concentration (CMC) than 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol. The contact angle between them can be reduced. Through this, it is possible to increase the impregnation rate of the perfluorinated sulfonated ionomer.

2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol may be represented by Formula 1 and Formula 1 below, and related products include Triton X-100 manufactured by Rohm & Haas.

[Formula 1]

C ₁₄ H ₂₂ O(C ₂ H ₄ O) _n

(n = 9 - 10)

[Structural Formula 1]

Nonyl phenoxypolyethoxylethanol can be represented by the following Chemical Formulas 2 and 2, and a related product is IGEPAL CO-630 from Rhodia.

[Formula 2]

H(C ₂ H ₄ O) _n O(C ₆ H ₄ )C ₉ H ₁₉

(n = 9 - 10)

[Structural Formula 2]

The solvent may be a hydrophilic solvent. By using a hydrophilic solvent, the perfluorinated sulfonated ionomer can be efficiently impregnated into the pores of the support by acting together with the hydrocarbon-based nonionic surfactant. The solvent is not particularly limited, and may be a mixture of at least one polar solvent such as water, Isopropanol and n-Propanol.

In this step, the hydrocarbon-based nonionic surfactant may include at least one of 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol and nonyl phenoxypolyethoxylethanol, and the hydrocarbon-based nonionic surfactant The content of the ionic surfactant may be 0.5 to 5 parts by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution. In addition, when the hydrocarbon-based nonionic surfactant is 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol, the content of the hydrocarbon-based nonionic surfactant is, It may be 1 to 2 parts by weight, preferably 1.3 to 1.7 parts by weight, based on 100 parts by weight of the ionomer solution, and when the hydrocarbon-based nonionic surfactant is nonyl phenoxypolyethoxylethanol, the content of the hydrocarbon-based nonionic surfactant is overpaid It may be 0.1 to 1 parts by weight, preferably 0.3 to 0.7 parts by weight, based on 100 parts by weight of the sub-sulfonated ionomer solution. When the content of the hydrocarbon-based nonionic surfactant is too low, there is a problem of low ionic conductivity and moisture content, and when the content of the hydrocarbon-based nonionic surfactant is too high, there is a problem of low ionic conductivity.

The perfluorinated sulfonated ionomer may be provided to the extent that it can be sufficiently impregnated into the support. As described above, in the manufacturing process of the embodiment of the present invention, the perfluorinated sulfonated ionomer is provided in a solution state, and the content of the perfluorinated sulfonated ionomer with respect to the total weight of the perfluorinated sulfonated ionomer solution is, It may be 1 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the sulfonated ionomer solution. When the content of the perfluorinated sulfonated ionomer is too low, there is a problem of low ionic conductivity, and when the content is too high, the price increases and physical properties decrease.

This step may be performed by sequentially or simultaneously mixing a perfluorinated sulfonated ionomer and a hydrocarbon-based nonionic surfactant in a solvent and stirring.

In the step of impregnating the support with the mixed solution, the support may have a plurality of pores formed therein, and the perfluorinated sulfonated ionomer is impregnated inside the pores and disposed to reduce the content of the perfluorinated sulfonated ionomer while reducing the ion conductivity. can be improved and cost can be reduced. In addition, since the perfluorinated sulfonated ionomer is impregnated inside the support, mechanical properties can be supplemented and dimensional stability can be improved.

The support has excellent chemical stability, heat resistance, and mechanical properties, and may be generally used in the field of fuel cells. Specifically, the support may include at least one of polytetrafluoroethylene (PTFE), polyethylene (PE), polyvinylidene fluoride (PVdF), polyimide (PI), nylon, polypropylene (PP), and cellulose. can The support may be formed of a single layer, but if necessary, several layers may be laminated.

Before performing this step, the step of washing the support may be performed. In this way, impurities can be removed, and the surface properties of the support can be favorably changed for impregnation. In this step, the support may be washed using an organic solvent, and in this case, the support may be heated to 40 to 70° C., preferably 50 to 60° C., and then washed. This can improve the cleaning effect.

The step of impregnating the support with the mixed solution may be performed by pouring the mixed solution onto the support or by putting the support into a container on which the mixed solution is supported. The impregnation time in this step may be 10 to 30 hours.

The drying of the mixed solution is performed to remove the solvent from the impregnated support and the mixed solution. In one example, it can be carried out by putting the impregnated support and the mixed solution in a dryer. The drying conditions are not particularly limited, but may be performed at 100° C. for 30 minutes.

Next, distilled water is poured into a container containing the dried support and the mixed solution, and the mixture of the support and the dried mixture may be immersed in water. This step can be performed for about 24 hours. Through this process, H ⁺ to the SO ^-3 group may be sufficiently substituted to improve conductivity.

After the step of impregnating the support with the mixed solution, the step of dissolving the surfactant may be further included, and this step may be performed after the drying and immersion steps described above. This step may be for removing the surfactant remaining after reacting from the support. This step may be performed by washing the support and the dried mixture using an organic solvent or immersing the support and the dried mixture in an organic solvent. The organic solvent may preferably be isopropyl alcohol, and may be carried out for 5 to 15 minutes.

The step of removing the impurities is a step of removing unnecessary materials and unreacted materials from the support. In this step, the support can be washed using an acid solution, preferably sulfuric acid. Thereafter, drying and washing may be repeatedly performed as needed.

Manufacture of reinforced composite membrane for fuel cell

Example 1 (T _0.5 )

As a perfluorinated sulfonated ionomer solution, 2 g of Sigma Aldrich's Nafion mixed solution (Product number: 274704) was used. The content of Nafion included in the Nafion mixed solution is 5 parts by weight based on 100 parts by weight of the Nafion mixed solution, and the solvent is water, isopropyl alcohol and n-propyl alcohol mixed in a volume ratio of 20:44:36 it has become Triton X-100 of Rohm & Haas was used as a hydrocarbon-based nonionic surfactant, and 0.01 g of the Triton X-100 was mixed and stirred so that 0.5 parts by weight based on 100 parts by weight of the Nafion mixed solution was mixed and stirred. was prepared.

A PTFE support (5 cm x 5 cm, about 0.005 g to 0.008 g) was prepared as a porous support, and the support was heated to 55 °C and washed with acetone.

Next, the support was impregnated in the mixed solution and maintained for 24 hours.

Next, the support and the mixed solution were put in a dryer and dried at 100° C. for 30 minutes to remove the solvent.

Next, the dried support and mixture were placed in distilled water and maintained for 24 hours.

Next, the support and the mixture were placed in isopropyl alcohol and maintained for 10 minutes.

Next, the support and the mixture were soaked in 1N sulfuric acid solution for 4 hours to remove impurities to prepare a reinforced composite membrane for a fuel cell.

Example 2 (T _One )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that 0.02 g was added so that the content of Triton X-100 was 1.0 parts by weight based on 100 parts by weight of the Nafion mixed solution when preparing the mixed solution.

Example 3 (T _1.5 )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that 0.03 g was added so that the content of Triton X-100 was 1.5 parts by weight based on 100 parts by weight of the Nafion mixed solution when preparing the mixed solution.

Example 4 (T ₂ )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that 0.04 g was added so that the content of Triton X-100 was 2.0 parts by weight based on 100 parts by weight of the Nafion mixed solution when preparing the mixed solution.

Example 5 (T ₃ )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that 0.06 g was added so that the content of Triton X-100 was 3.0 parts by weight based on 100 parts by weight of the Nafion mixed solution when preparing the mixed solution.

Example 6 (T ₅ )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that 0.10 g was added so that the content of Triton X-100 was 5.0 parts by weight based on 100 parts by weight of the Nafion mixed solution when preparing the mixed solution.

Example 7 (I _0.5 )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.01 g was added so that the content of IGEPAL CO-630 was 0.5 parts by weight based on 100 parts by weight of the Nafion mixed solution Example 1 A reinforced composite membrane for a fuel cell was manufactured in the same manner as described above.

Example 8 (I _One )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.02 g was added so that the content of IGEPAL CO-630 was 1.0 parts by weight based on 100 parts by weight of the Nafion mixed solution Example 1 A reinforced composite membrane for a fuel cell was manufactured in the same manner as described above.

Example 9 (I _1.5 )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.03 g was added so that the content of IGEPAL CO-630 was 1.5 parts by weight based on 100 parts by weight of the Nafion mixed solution Example 1 A reinforced composite membrane for a fuel cell was manufactured in the same manner as described above.

Example 10 (I ₂ )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.04 g was added so that the content of IGEPAL CO-630 was 2.0 parts by weight based on 100 parts by weight of the Nafion mixed solution Example 1 A reinforced composite membrane for a fuel cell was manufactured in the same manner as described above.

Example 11 (I ₃ )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.06 g was added so that the content of IGEPAL CO-630 was 3.0 parts by weight based on 100 parts by weight of the Nafion mixed solution Example 1 A reinforced composite membrane for a fuel cell was manufactured in the same manner as described above.

Example 12 (I ₅ )

When preparing the mixed solution, Rhodia's IGEPAL CO-630 was added instead of Triton X-100, and 0.10 g was added so that the content of IGEPAL CO-630 was 5.0 parts by weight to 100 parts by weight of the Nafion mixed solution. In the same manner, a reinforced composite membrane for a fuel cell was prepared.

Comparative Example 1 (T ₀ )

A reinforced composite membrane for a fuel cell was prepared in the same manner as in Example 1, except that only a perfluorinated sulfonated ionomer solution was used without adding a hydrocarbon-based nonionic surfactant when preparing the mixed solution.

Fourier Transform Infrared Spectroscopy (FT IR) Analysis

The resolution was 4 cm ^-1 , and the spectrum was observed at a wavelength range of 650 to 4,000 cm ^-1 to determine whether the impregnation or the surfactant was dissolved.

1 and 2 show the FT IR analysis results of Examples 1 to 12 and Comparative Example 1. 1 and 2 , in Examples 1 to 12, SO (1057 cm ^-1 ) and COC (976 cm ^-1 ) peaks are observed, and it can be confirmed that Nafion is impregnated into the support.

Analysis of proton conductivity

Ion conductivity was analyzed using an impedance measuring instrument under AC power conditions of 0.6 V, 0.1-105 Hz frequency range, and 5 mV voltage strength.

3 and 4 show the proton conductivity analysis results of Examples 1 to 12 and Comparative Example 1. Referring to FIGS. 3 and 4 , in the example to which Triton x-100 was applied, the ionic conductivity of Example 3 in which the content of Triton x-100 was contained in 1.5 parts by weight based on the entire mixed solution was the highest. In the example to which IGEPAL CO-630 was applied, the ionic conductivity of Example 7 in which the content of IGEPAL CO-630 was 0.5 parts by weight based on the entire mixed solution was found to be the highest.

Water uptake analysis

의 물에서 24시간 함수시키고 과도한 물기를 제거 후 건조기에 5분 건조하여 무게를 측정하였다. 80 by drying the reinforced composite film prepared in each Example and Comparative Example

After soaking in water for 24 hours, removing excess moisture, drying in a dryer for 5 minutes, and measuring the weight.

5 and 6 show the moisture content analysis results of Examples 1 to 12 and Comparative Example 1. 5 and 6, in the example to which Triton x-100 was applied, the moisture content of Example 3, in which the content of Triton x-100 contained 1.5 parts by weight with respect to the entire mixed solution, was 63%, the highest, and IGEPAL CO In the example to which -630 was applied, the ionic conductivity of Example 7 in which the content of IGEPAL CO-630 was 0.5 parts by weight with respect to the entire mixed solution was found to be the highest.

Thermogravimetric Analysis (TGA)

Example 3 (T _1.5 ), Example 7 (I _0.5 ), PTFE support (PTFE membrane), and DuPont (Dupont) for the Nafion 212 membrane (Nafion) was subjected to thermogravimetric analysis. The weight loss of the sample was measured by raising the temperature from 30 to 700 °C in a nitrogen atmosphere at 10 °C/min.

7 shows the results of thermal gravimetric analysis. In this experiment, the thermal decomposition temperature of the Nafion 212 membrane was 420 °C, the thermal decomposition temperature of the PTEF support was 570 °C, the thermal decomposition temperature of Example 3 was 480 °C, and the thermal decomposition temperature of Example 7 was 480 °C. Compared with the Nafion pure membrane, the thermal decomposition temperature of Examples 3 and 7 is increased, and it is judged that the thermal properties are excellent.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

Claims (12)

preparing a mixed solution by mixing a perfluorinated sulfonated ionomer solution and a hydrocarbon-based nonionic surfactant; and
Including; impregnating the mixed solution in the support;
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
The hydrocarbon-based nonionic surfactant comprises at least one of 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol and nonyl phenoxypolyethoxylethanol,
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
The hydrocarbon-based nonionic surfactant will include a material represented by the following structural formula 1,
Manufacturing method of reinforced composite membrane for fuel cell:
[Structural Formula 1]

.
2. The method of claim 1
The hydrocarbon-based nonionic surfactant will include a material represented by the following structural formula 2,
Manufacturing method of reinforced composite membrane for fuel cell:
[Structural Formula 2]

.
2. The method of claim 1
The content of the hydrocarbon-based nonionic surfactant is 0.5 to 5 parts by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution,
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
When the hydrocarbon-based nonionic surfactant is 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol, the content of the hydrocarbon-based nonionic surfactant is the perfluorinated sulfonated ionomer solution 1 to 2 parts by weight based on 100 parts by weight,
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
When the hydrocarbon-based nonionic surfactant is nonyl phenoxypolyethoxylethanol, the content of the hydrocarbon-based nonionic surfactant is 0.1 to 1 part by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution,
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
The perfluorinated sulfonated ionomer solution includes a perfluorinated sulfonated ionomer and a solvent,
The content of the perfluorinated sulfonated ionomer is 1 to 10 parts by weight based on 100 parts by weight of the perfluorinated sulfonated ionomer solution,
A method for manufacturing a reinforced composite membrane for a fuel cell.
9. The method of claim 8,
The solvent included in the perfluorinated sulfonated ionomer solution includes at least one of water and an organic solvent,
A method for manufacturing a reinforced composite membrane for a fuel cell.
9. The method of claim 8,
The perfluorinated sulfonated ionomer solution is any one of Nafion, Flemion, Aquivion, 3M FSA ionomer and Aciplex,
A method for manufacturing a reinforced composite membrane for a fuel cell.
2. The method of claim 1
After impregnating the support with the mixed solution,
Further comprising the step of dissolving the surfactant,
A method for manufacturing a reinforced composite membrane for a fuel cell.
A reinforced composite membrane for a fuel cell manufactured by the manufacturing method of claim 1.

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