KR102599935B1 - Ion exchange membrane for fuel cell with layer by layer, method of manufacturing ion exchange membrane for fuel cell and fuel cell comprising the same - Google Patents

Abstract

The present invention discloses an ion exchange membrane for fuel cells, a method for manufacturing the same, and a fuel cell including the same. The ion exchange membrane for a fuel cell of the present invention includes a polymer electrolyte membrane formed of a first compound having the structure of the following formula (1), wherein the polymer electrolyte membrane has a first surface layer in which cerium nanoparticles are dispersed on one side and a first surface layer on the opposite side of the first surface layer. It is characterized by forming a layer-by-layer structure including a second surface layer in which cerium nanoparticles are dispersed, and has the advantage of blocking electron flow and ensuring oxidation stability.

Description

Ion exchange membrane for fuel cells having a layered structure, manufacturing method thereof, and fuel cell comprising the same

The present invention relates to an ion exchange membrane for fuel cells that forms a layer-by-layer structure by dispersing cerium nanoparticles on both sides of a sulfonated polyarylene ether sulfone (PAES) electrolyte membrane, a method of manufacturing the same, and a fuel cell containing the same. It's about.

The polymer electrolyte membrane used in a cation exchange membrane fuel cell (PEMFC) serves as a passage through which cations, the main driving force of the fuel cell, move, and the performance and durability of this electrolyte membrane have a significant impact on the efficiency of the fuel cell. do.

Currently commercialized electrolyte membranes with the Nafion structure exhibit high ionic conductivity, but have the disadvantage of being expensive and having poor chemical durability as they are decomposed by H·, HO·, or HOO· radical ions generated during fuel cell operation.

To solve this problem, attempts have been made to introduce cerium nanoparticles into polymer electrolyte membranes, but the disadvantage is that electrons move between electrolyte membranes through cerium atoms, causing a decrease in membrane performance.

One purpose of the present invention is to solve the disadvantage of deteriorating the performance of the membrane due to electrons moving into the electrolyte membrane through cerium nanoparticles, and to create a fuel having a layer-by-layer structure in which cerium nanoparticles are dispersed only in the surface layer. The object is to provide an ion exchange membrane for a battery and a fuel cell including the same.

Another object of the present invention is to provide a method for manufacturing an ion exchange membrane for a fuel cell having a layer-by-layer structure in which cerium nanoparticles are dispersed only in the surface layer, and an ion exchange membrane for a fuel cell manufactured through the method.

An ion exchange membrane for a fuel cell for the purpose of the present invention includes a polymer electrolyte membrane formed of a first compound having the structure of the following formula (1), wherein the polymer electrolyte membrane includes a first surface layer with cerium nanoparticles dispersed on one side and the first surface layer with cerium nanoparticles dispersed on one side. It is characterized in that it forms a layered structure including a second surface layer in which cerium nanoparticles are dispersed on the opposite side of the surface layer:

<Formula 1>

In one embodiment, the first and second surface layers may each have a thickness of 1 to 10 ㎛.

In one embodiment, the first and second surface layers may each have 2 to 4 wt% of cerium nanoparticles dispersed relative to the surface layer of the ion exchange membrane for a fuel cell. Specifically, it may be dispersed at 2 to 4 wt% based on the polymer contained in the first and second surface layers of the ion exchange membrane for fuel cells.

In one embodiment, the cerium nanoparticles may be cerium oxide (CeO ₂ ) nanoparticles.

In one embodiment, the thickness of the ion exchange membrane for a fuel cell may be 80 to 100 μm.

A fuel cell for one purpose of the present invention includes an anode, a cathode, and an ion exchange membrane for a fuel cell of the present invention disposed between the anode and the cathode.

A method of manufacturing an ion exchange membrane for a fuel cell for another purpose of the present invention includes a first step of preparing a first compound having the structure of the following formula (1) and mixing cerium nanoparticles dispersed in a polymer solution in a thin film formed from the first compound. It includes a second step of applying a solution, and the second step is characterized in that a mixed solution is applied to both sides of the thin film formed of the first compound to form a layered structure.

In one embodiment, the first step may be performed by grafting a sulfonic acid group containing an alkyl group to a benzene ring of poly(arylene ethersulfone) containing a benzene ring. The alkyl group may be a propane group.

In one embodiment, the grafting may be performed using sodium 3-mercapto-1-propanesulfonate.

In one embodiment, the second step may be applied through a spray method.

In one embodiment, the polymer solution is a group consisting of SPI (Sulfonated polyimide), SPEEK (Sulfonated poly(ether ether ketone)), SPAEK (Sulfonated poly(arylene ether ketone)), and SPAES (Sulfonated poly(arylene ether sulfone)) It may be any one selected from.

An ion exchange membrane for a fuel cell for another purpose of the present invention is manufactured through the method for manufacturing an ion exchange membrane for a fuel cell of the present invention, and includes a polymer electrolyte membrane formed of a first compound having the structure of the following formula (1), wherein the polymer electrolyte membrane It includes a first surface layer in which cerium nanoparticles are dispersed on one side and a second surface layer in which cerium nanoparticles are dispersed in an opposite side of the first surface layer.

In one embodiment, the first and second surface layers may each have a thickness of 1 to 10 ㎛.

In one embodiment, the first and second surface layers may each have cerium nanoparticles dispersed in an amount of 2 to 4 wt% based on the total weight of the ion exchange membrane for a fuel cell.

In one embodiment, the cerium nanoparticles may be cerium oxide (CeO ₂ ) nanoparticles.

In one embodiment, the thickness of the ion exchange membrane for a fuel cell may be 80 to 100 μm.

According to the present invention, it is possible to primarily prevent the main chain of the electrolyte membrane from being deteriorated by radicals by grafting a sulfonic acid group containing an alkyl group to prevent radical ions from approaching the main chain, and cerium nanoparticles are placed on both sides of the electrolyte membrane. By preventing electrons from crossing the membrane and ensuring oxidation stability through the dispersed layered structure, there is an advantage in preventing secondary chemical deterioration while maintaining the performance of the cell including the ion exchange membrane.

In addition, the inclusion of a layered structure has the advantage of preventing the performance of the film from deteriorating due to the movement of electrons and cerium nanoparticles, which are conductors, compared to a composite in which cerium nanoparticles are dispersed throughout.

1 is a diagram for explaining an ion exchange membrane for a fuel cell having a layered structure, a manufacturing method thereof, and a fuel cell including the same.
Figure 2 is a cross-sectional SEM and EDS image of an ion exchange membrane for a fuel cell with a layered structure manufactured according to Example 2 of the present invention.
Figure 3 is a FE-SEM image and component analysis diagram for analyzing the structure and components of ion exchange membranes for fuel cells manufactured according to Examples 1 and 2 of the present invention.
Figure 4 is a graph for comparing the cation conductivity of ion exchange membranes for fuel cells with a layered structure manufactured according to Examples and Comparative Examples of the present invention.
Figure 5 is a Nyquist plot showing the interfacial ohmic resistance according to the concentration of cerium nanoparticles of an ion exchange membrane for a layered fuel cell manufactured according to examples and comparative examples of the present invention.
Figure 6 is a diagram showing the water content and swelling rate according to the ratio of sulfonic acid groups and the water content and swelling rate according to the concentration of cerium nanoparticles of the ion exchange membrane for a fuel cell with a layered structure manufactured according to examples and comparative examples of the invention, respectively. .
Figure 7 is a graph showing the weight change after the Fenton test over time to evaluate the chemical stability of the ion exchange membrane for a layered fuel cell manufactured according to Examples and Comparative Examples of the present invention.
Figure 8 is a graph showing the open circuit voltage of the electrolyte membrane at 90°C and 30% relative humidity for evaluating the voltage loss rate of the ion exchange membrane for a layered fuel cell manufactured according to the examples and comparative examples of the present invention.
Figure 9 is a graph showing the voltage and power density of a single cell measured in order to analyze the performance of the ion exchange membrane for fuel cells manufactured according to Examples and Comparative Examples of the present invention when applied to a single cell.
Figure 10 is a graph showing the voltage and power density of an ion exchange membrane subjected to an open circuit voltage test for 100 hours to measure the stability of a cell containing an ion exchange membrane for a fuel cell manufactured according to embodiments of the present invention.
Figure 11 shows a composite electrolyte membrane (composite) that does not have a layered structure and only contains cerium oxide nanoparticles inside the ion exchange membrane, in order to examine the effect of the ion exchange membrane for a fuel cell with a layered structure manufactured according to embodiments of the present invention. This is a graph showing the voltage and power density of cells including ion exchange membranes for each fuel cell, using as a comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Since the present invention can be subject to various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features or steps. , it should be understood that it does not exclude in advance the possibility of the existence or addition of operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

The ion exchange membrane for a fuel cell of the present invention, its manufacturing method, and a fuel cell including the same will be described with reference to FIG. 1.

Referring to Figure 1, the ion exchange membrane for a fuel cell of the present invention is a hydrocarbon-based electrolyte membrane and includes a polymer electrolyte membrane formed of a first compound having the structure of the following formula (1), and the polymer electrolyte membrane has cerium nanoparticles dispersed on one side. It is characterized in that it forms a layer-by-layer structure including a first surface layer and a second surface layer in which cerium nanoparticles are dispersed on the opposite side of the first surface layer.

<Formula 1>

The first compound has a main chain of poly(arylene ether sulfone) (hereinafter referred to as PAES) having the structure of Formula 2 below, and a sulfonic acid group containing an alkyl group is grafted to the side chain ( It may have a grafting structure.

The ratio of the sulfonic acid group may be about 120 to 160 relative to the mole fraction of the ion exchange membrane for a fuel cell.

<Formula 2>

The polymer electrolyte membrane formed from the first compound is less expensive than the conventional Nafion electrolyte membrane and has high proton conductivity, so it can be very suitable as an electrolyte membrane for the fuel cell of the present invention.

The first and second surface layers may be formed on the first side of the polymer electrolyte membrane and the second side opposite the first side, respectively, and may have a structure in which cerium particles are dispersed in the polymer electrolyte membrane.

The thickness of the first and second surface layers may each be 10 ㎛ or less. When the thickness of the first and second surface layers exceeds about 10㎛, cerium as well as polymers that transmit ions are distributed in the first and second surface layers, forming a channel through which cerium particles can transmit ions ( Clusters) can reduce ionic conductivity. That is, as the first and second surface layers become thicker, it becomes more difficult for ions to pass across the electrolyte membrane, which may lead to a decrease in ionic conductivity. Therefore, it is preferable that the thickness is such that resistance due to the thickness does not deteriorate cell performance. Specifically, the thickness of the first and second surface layers may be preferably about 1 to 10 μm, respectively.

The first and second surface layers may each have cerium nanoparticles dispersed in an amount of about 2 to 4 wt% based on the total polymer of the first and second surface layers. If the cerium nanoparticles are dispersed at less than about 2 wt%, the radical removal ability of the cerium nanoparticles may be lowered, whereas if the cerium nanoparticles are dispersed at more than about 4 wt%, the cerium nanoparticles may be able to transfer ions. It can block the channels in the electrolyte membrane, hindering the movement of ions into the electrolyte membrane, and there is a problem in that the moisture absorption rate is lowered due to the combination of cerium ions (+) and sulfonic acid groups (-) inside. Therefore, in order to secure ionic conductivity performance and at the same time perform the role of a radical scavenger above a certain level, an appropriate amount of cerium nanoparticles can be applied in the present invention.

As for the ion exchange membrane for fuel cells, if the thickness of the membrane becomes thin at the same concentration of cerium nanoparticles, the effect of preventing oxidation decreases, and if the membrane thickness becomes thick, cell performance may decrease.

Therefore, the preferred ion exchange membrane for fuel cells of the present invention may have first and second surface layers with a thickness of 10 μm, and the cerium nanoparticles may be dispersed at 4 wt% relative to the entire ion exchange membrane for fuel cells.

The size of the cerium nanoparticles is not particularly limited as long as they can be dispersed in the polymer electrolyte membrane, but preferably, they may have a size of about 5 nm to 10 nm. Cerium nanoparticles may have the form of uniformly sized spheres, plates, rods, and polymorphs, but are not necessarily limited thereto.

In one embodiment, the cerium nanoparticles may be cerium oxide (CeO ₂ ) nanoparticles.

In one embodiment, the thickness of the ion exchange membrane for a fuel cell may be 80 to 100 ㎛.

Meanwhile, the method for manufacturing an ion exchange membrane for a fuel cell of the present invention includes a first step of preparing a first compound having the structure of Formula 1 and a mixed solution in which cerium nanoparticles are dispersed in a polymer solution in a thin film formed of the first compound. It includes a second step of applying, and the second step is characterized in that a mixed solution is applied to both sides of the thin film formed of the first compound to form a layered structure.

The first step may be performed by grafting a sulfonic acid group containing an alkyl group onto poly(arylene ethersulfone) having the structure of Formula 2. Specifically, first, poly(arylene ethersulfone) having the structure of Formula 2 is 4,4-bis(4-hydroxy-3-methylphenyl)propane (2,2-bis(4-hydroxy-3-methylphenyl) )propane), 2,2-bis(4-hydroxyphenyl)propane) and bis(4-fluorophenyl)sulfone) It can be synthesized using

Grafting of the sulfonic acid group containing the alkyl group can be performed using sodium 3-mercapto-1-propanesulfonate.

The ratio of sulfonic acid groups of the first compound prepared through the first step may be about 120 to 160 compared to the mole fraction of the ion exchange membrane for fuel cells.

The mixed solution is a solution in which cerium nanoparticles are dispersed in a polymer solution. The polymer solution is, for example, SPI (Sulfonated polyimide), SPEEK (Sulfonated poly(ether ether ketone)), SPAEK (Sulfonated poly(arylene ether ketone)) ) and SPAES (Sulfonated poly(arylene ether sulfone)). Preferably, the polymer solution may be SPAES (Sulfonated poly(arylene ether sulfone)).

The size of the cerium nanoparticles is not particularly limited as long as they can be dispersed in the polymer electrolyte membrane, but preferably, they may have a size of about 5 nm to 10 nm. Cerium nanoparticles may have the form of uniformly sized spheres, plates, rods, and polymorphs, but are not necessarily limited thereto.

In one embodiment, the cerium nanoparticles may be cerium oxide (CeO2) nanoparticles.

The second step may be performed through a spray method. The spray method can be performed through a commonly used spray device, and the spray device is not particularly limited in the present invention. The application may be performed on each of the first side and the second side opposite the first side of the thin film formed of the first compound.

In the second step, application may be performed to the extent that the layer in which the cerium nanoparticles are dispersed has a thickness of about 10 μm or less. If the layer in which cerium nanoparticles are dispersed exceeds 10㎛, there is a problem in that ionic conductivity decreases. Therefore, the second step may be performed so that the layer in which the cerium nanoparticles are dispersed has a thickness of about 1 to 10 μm. Additionally, the application may be performed so that the cerium nanoparticles are dispersed in an amount of about 2 to 4 wt% based on the total surface layer in which the cerium nanoparticles are dispersed.

The ion exchange membrane for a fuel cell manufactured through the above manufacturing method is a thin film formed of a first compound. The thin film formed of the first compound includes a first surface layer in which cerium nanoparticles are dispersed and cerium nanoparticles dispersed on the opposite side of the first surface layer. It is characterized by having a layer-by-layer structure including a second surface layer, and may have a thickness of about 80 to 100 ㎛.

The fuel cell of the present invention includes an anode, a cathode, and a polymer electrolyte membrane disposed between the anode and the cathode and formed of a first compound having the structure of Formula 1, wherein the polymer electrolyte membrane has cerium nanoparticles dispersed on one side. It is characterized in that it forms a layered structure including a first surface layer and a second surface layer in which cerium nanoparticles are dispersed on a surface opposite to the first surface layer.

According to the present invention, cerium nanoparticles are applied in a layered structure to a poly(arylene ether sulfone) polymer electrolyte membrane containing a sulfonic acid group, thereby blocking electron and oxygen transfer into the polymer electrolyte membrane to ensure oxidation stability and secured ions. It can provide conductivity.

Hereinafter, the ion exchange membrane for a fuel cell having a layered structure of the present invention, its manufacturing method, and a fuel cell including the same will be described in more detail through specific examples and comparative examples. However, the embodiments of the present invention are only some embodiments of the present invention, and the scope of the present invention is not limited to the following examples.

Example 1: PAES140-2CeO ₂ membrane

① PAES synthesis

PAES is a monomer called 4,4-bis(4-hydroxy-3-methylphenyl)propane (2,2-bis(4-hydroxy-3-methylphenyl)propane), 2,2-bis(4-hydroxyphenyl) It was synthesized using propane (2,2-bis(4-hydroxyphenyl)propane) and bis(4-fluorophenyl)sulfone.

② SPAES synthesis

The PAES prepared above was used as a main chain, and sodium 3-mercapto-1-propanesulfonate was grafted onto the main chain to produce sulfonated poly(arylene ether sulfone). (arylene ether sulfone), SPAES) was prepared and the sulfonic acid group was activated to prepare a SPAES polymer electrolyte membrane. The ratio of sulfonic acid groups in the prepared SPAES membrane was 140% compared to the entire membrane.

③ Manufacturing of layer-by-layer structure

A spray technique was used to create a layered cation exchange membrane containing cerium oxide nanoparticles only on the surface layer of the SPAES polymer electrolyte membrane. Cerium oxide nanoparticles were dispersed in a polymer solution and then uniformly applied to both surfaces of the SPAES polymer electrolyte membrane using a spray to prepare a SPAES140-2CeO2 membrane according to Example 1 of the present invention. The concentration of cerium oxide nanoparticles in the surface layer of the ion exchange membrane for fuel cells was 2%. The thickness of the prepared SPAES140-2CeO ₂ film was about 100 ㎛, and the surface layer containing cerium nanoparticles was 10 ㎛ each.

Example 2: SPAES140-4CeO ₂ membrane

A SPAES140-4CeO ₂ membrane was manufactured through the same process as Example 1 of the present invention, except that the concentration of cerium oxide nanoparticles was set to 4% relative to the entire surface layer of the ion exchange membrane for fuel cells. The thickness of the prepared SPAES140-4CeO ₂ film was about 100 ㎛, and the surface layer containing cerium nanoparticles was 10 ㎛ each.

Comparative Example 1: SPAES120 membrane

Through the SPAES synthesis process in Example 1 of the present invention, a SPAES120 membrane was prepared in which the ratio of sulfonic acid groups in the SPAES membrane was 120.

Comparative Example 2: SPAES140 membrane

Through the SPAES synthesis process in Example 1 of the present invention, a SPAES140 membrane was prepared in which the ratio of sulfonic acid groups in the SPAES membrane was 140.

Comparative Example 3: SPAES160 membrane

Through the SPAES synthesis process in Example 1 of the present invention, a SPAES160 membrane was prepared in which the ratio of sulfonic acid groups in the SPAES membrane was 160.

Comparative Example 4: Nafion 212 membrane

Nafion 212 (Nafion solution 5wt% EW1100, Dupont, USA) was used.

Experimental Example 1: Structure and component analysis

In order to analyze the structure of the ion exchange membrane for a fuel cell manufactured according to Example 2 of the present invention, images were obtained using SEM and EDS, and the results are shown in FIG. 2.

Referring to Figure 2, the thickness of the ion exchange membrane for a fuel cell manufactured according to Example 2 is about 100㎛, the surface layer containing cerium oxide nanoparticles is about 10㎛, and the central layer made of SPAES is about 80㎛. You can check it. In addition, it was confirmed that the cerium element (yellow) was evenly distributed on the surface of the exchange membrane, and the oxygen element (green) contained in the cerium oxide particles and polymer was evenly distributed throughout the cross section.

The structure and components of the ion exchange membrane for fuel cells manufactured according to Examples 1 and 2 of the present invention were analyzed, and the results are shown in FIG. 3.

Referring to Figure 3, since the number of cerium oxide nanoparticles in the surface layer of the ion exchange membrane containing 4% cerium oxide nanoparticles is greater than that of the ion exchange membrane containing 2% cerium oxide nanoparticles, the SPAES140-4CeO ₂ ion exchange membrane is larger than the SPAES140-2CeO ₂ ion exchange membrane. It can be expected that the anti-oxidation ability of is high.

Experimental Example 2: Measurement of ion conductivity and ion exchange capacity

The ion conductivity and ion exchange capacity (ICE) of each ion exchange membrane for fuel cells manufactured according to the examples and comparative examples of the present invention were measured, and these are shown in Figure 4 and Table 1, respectively.

IEC (theory)
( meq g ^-1 ) IEC (appropriate)
( meq g ^-1 ) IEC(NMR)
( meq g ^-1 ) SPAES120 1.865 1.745 1.824 SPAES140 2.086 1.979 2.036 SPAES160 2.251 2.103 2.120 _{SPAES140-2CeO2} 2.031 1.844 - _{SPAES140-4CeO2} 2.003 1.792 - Nafion 212 - 0.870 -

Referring to Figure 4 and Table 1 together, it can be seen that the ion exchange capacity and cation conductivity increase as the sulfonic acid group contained in the polymer increases.

Additionally, in order to determine the ion conductivity according to the cerium particle concentration, the Nyquist curves of each of the ion exchange membranes for fuel cells manufactured according to Examples 1 and 2 and Comparative Example 2 of the present invention were derived, and the results were is shown in Figure 5.

Referring to Figure 5, it can be seen that the resistance value of the ion exchange membrane increases as the concentration of cerium nanoparticles contained in the ion exchange membrane increases. An increase in resistance value may mean that ionic conductivity in the direction across the ion exchange membrane decreases. The layer in which cerium nanoparticles are dispersed is not only formed of a polymer that transmits ions, but also cerium nanoparticles that block the channel through which ions can transmit are also dispersed, so the layer in which cerium nanoparticles are dispersed becomes very thick or the dispersed cerium As the concentration of nanoparticles increases, the path for ions to pass through the membrane becomes longer, which can be a factor that hinders the movement of ions. Therefore, it can be seen that it is important to secure the ionic conductivity performance of the present invention by controlling the amount of cerium nanoparticles dispersed and the thickness of the dispersed layer.

Referring to the ionic conductivity in FIG. 4 and the resistance value in FIG. 5, it can be seen that while the resistance value of the surface of the SPAES140-4CeO ₂ membrane increases, the ionic conductivity does not show a significant difference from that of the SPAES140 and SPAES140-2CeO ₂ membranes. This may mean that the 4% cerium oxide nanoparticle coating layer does not significantly affect the conductivity of the ion exchange membrane.

Experimental Example 3: Water content and swelling rate analysis

The ratio of sulfonic acid groups of ion exchange membranes for fuel cells manufactured according to examples and comparative examples of the present invention and the moisture content and swelling ratio according to temperature change are shown in FIG. 6.

Referring to Figure 6, it can be seen that both water content and swelling ratio increase as the temperature increases in the ion exchange membrane for SPAES fuel cells, which contains more sulfonic acid groups compared to the Nafion membrane. It can be seen that the ion exchange membrane for a fuel cell with a layered structure containing cerium oxide nanoparticles on the surface manufactured according to an embodiment of the present invention exhibits a moisture content and swelling ratio similar to that of the SPAES140 membrane.

Experimental Example 4: Chemical stability evaluation

To measure the oxidation stability of the ion exchange membrane for fuel cells manufactured according to the embodiments and comparative examples of the present invention, the ion exchange membrane was dissolved in Fenton reagent (2 wt.% H ₂ O ₂ and 2 ppm FeSO ₄ ) at 60°C. After soaking for 6 and 12 hours, the weight of the remaining film was measured, and the results are shown in Figure 7.

Referring to Figure 7, after treatment for 12 hours, the residual weight of the SPAES140 membrane was 52.36wt%, while the residual weight of the SPAES140-4CeO ₂ membrane was confirmed to have improved to 77.46wt%. Through this, it can be seen that the cerium oxide nanoparticles removed the radicals generated at the electrode.

Experimental Example 5: Voltage loss rate evaluation

To measure the voltage loss rate of the ion exchange membrane for fuel cells manufactured according to an example and comparative examples of the present invention, the open circuit voltage of the electrolyte membrane was measured at 90°C and 30% relative humidity, and the results are shown in FIG. 8. .

Referring to Figure 8, in the open circuit voltage test, it can be seen that the voltage change of the Nafion film decreased significantly after 50 hours, while the SPAES140-4CeO ₂ film showed a stable voltage even after 500 hours.

Experimental Example 6: Cell performance analysis

The voltage and power density were measured by applying the ion exchange membrane for fuel cells manufactured according to the examples and comparative examples of the present invention to a single cell of a polymer electrolyte membrane fuel cell (PEMFC), and the results are shown in the figure. Shown in 9.

Referring to FIG. 9, it can be seen that the addition of cerium nanoparticles slightly reduces the cell performance of the ion exchange membrane. The power densities of SPAES140, SPAES140-2CeO ₂ and SPAES140-4CeO ₂ films are 378.59, 367.49 and 363.67 mW/cm ² , respectively. This decrease in power density may be due to the adhesion between the electrolyte membrane and the surface layer applied while manufacturing the exchange membrane in a layered structure.

Next, to measure the stability of the cell, the voltage and power density of the ion exchange membrane that underwent an open circuit voltage test for 100 hours were measured, and the results are shown in Figure 10.

Referring to FIG. 10, as the voltage performance decreases at different rates in the polarization curve of FIG. 9, it can be said that each ion exchange membrane shows different membrane decomposition rates. The power density of the SPAES140-4CeO ₂ film decreased the least from 363.67mW/cm ² to 295.43mW/cm ² . These results show that cerium oxide nanoparticles scavenge radicals in the operation of fuel cells and prevent decomposition of the ion exchange membrane.

In order to examine the effect of the layer-by-layer structure, which is a characteristic of the present invention, the ion exchange membranes (LbL) of Examples 1 and 2 of the present invention with a layered structure and cerium oxide nanoparticles without a layered structure were mixed. The voltage and power density of each cell manufactured with a composite electrolyte membrane (composite) contained only inside the ion exchange membrane were measured, and the results are shown in FIG. 11.

Referring to FIG. 11, it can be seen that in the case of a composite film, the power density is greatly reduced. On the other hand, in the case of the layered structure (LbL), it can be seen that the decrease in power density is not significant compared to the composite film. This result can be expected to be because, in the case of a composite membrane, the electrons generated at the electrode move through the ion exchange membrane through the cerium oxide nanoparticles, and in the case of a layered structure (LbL), the cerium oxide nanoparticles It can be expected that electrons cannot move because there is an electrolyte membrane in the middle.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the following patent claims. You will understand that it is possible.

Claims (16)

It includes a polymer electrolyte membrane formed of a first compound having the structure of a material finally obtained through a reaction process of the following formula (1), wherein the polymer electrolyte membrane has a first surface layer in which cerium nanoparticles are dispersed on one side and an area opposite the first surface layer. It is characterized by forming a layered structure including a second surface layer in which cerium nanoparticles are dispersed on the surface,
The thickness of the first and second surface layers is 1㎛ to 10㎛, respectively,
The cerium nanoparticles exist only in the first and second surface layers, and are characterized in that they are dispersed in an amount of 2 to 4 wt% in the first and second surface layers, respectively.
Ion exchange membrane for fuel cells:
<Formula 1>

delete delete According to paragraph 1,
The cerium nanoparticles are characterized in that they are cerium oxide (CeO ₂ ) nanoparticles.
Ion exchange membrane for fuel cells.
According to paragraph 1,
Characterized in that the thickness of the ion exchange membrane for the fuel cell is 80 to 100 ㎛,
Ion exchange membrane for fuel cells.
anode;
cathode; and
Comprising: an ion exchange membrane for a fuel cell according to any one of claims 1, 4, and 5, disposed between the anode and the cathode;
fuel cell.
A first step of preparing a first compound having the structure of a material finally obtained through the reaction process of formula 1 below, and applying a mixed solution in which cerium nanoparticles are dispersed in a polymer solution to a thin film formed from the first compound. Includes 2 steps,
The second step is characterized in that a mixed solution is applied to both sides of the thin film formed of the first compound to form a layered structure,
In the layered structure, the thickness of the layer formed by applying the mixed solution to both sides of the thin film is 1㎛ to 10㎛, respectively,
Cerium nanoparticles exist only in the layer formed by applying a mixed solution to both sides of the thin film, and are characterized in that they are dispersed at 2 to 4 wt%.
Manufacturing method of ion exchange membrane for fuel cell:
<Formula 1>

In clause 7,
The first step is,
This is performed by grafting a sulfonic acid group containing an alkyl group onto poly(arylene ether sulfone),
Manufacturing method of ion exchange membrane for fuel cell.
According to clause 8,
The grafting is performed using sodium 3-mercapto-1-propanesulfonate,
Manufacturing method of ion exchange membrane for fuel cell.
In clause 7,
The second step is applied through a spray method,
Manufacturing method of ion exchange membrane for fuel cell.
In clause 7,
The polymer solution is any one selected from the group consisting of SPI (Sulfonated polyimide), SPEEK (Sulfonated poly(ether ether ketone)), SPAEK (Sulfonated poly(arylene ether ketone)), and SPAES (Sulfonated poly(arylene ether sulfone)). Characterized by,
Manufacturing method of ion exchange membrane for fuel cell.
In the ion exchange membrane for fuel cells manufactured according to the method of any one of claims 7 to 11,
The ion exchange membrane for the fuel cell is,
It includes a polymer electrolyte membrane formed of a first compound having the structure of the following formula (1), wherein the polymer electrolyte membrane includes a first surface layer in which cerium nanoparticles are dispersed on one side and a second surface layer in which cerium nanoparticles are dispersed on an opposite side of the first surface layer. Characterized by comprising a surface layer,
The thickness of the first and second surface layers is 1㎛ to 10㎛, respectively,
The cerium nanoparticles exist only in the first and second surface layers, and are characterized in that they are dispersed in an amount of 2 to 4 wt% in the first and second surface layers, respectively.
Ion exchange membrane for fuel cells.
delete delete According to clause 12,
The cerium nanoparticles are characterized in that they are cerium oxide (CeO ₂ ) nanoparticles.
Ion exchange membrane for fuel cells.
According to clause 12,
Characterized in that the thickness of the ion exchange membrane for the fuel cell is 80 to 100 ㎛,
Ion exchange membrane for fuel cells.