KR101195910B1 - Polymer electrolyte having chemically bonded phosphoric acid group, prepariong method of the same, and membrane electrode assembly and fuel cell using the same - Google Patents

Abstract

The present invention relates to a polymer electrolyte having a chemically bonded phosphate group, a method for manufacturing the same, a conductive polymer membrane including the polymer electrolyte, and a membrane-electrode assembly using the same, and a fuel cell including the same. When preparing a polymer electrolyte and a proton conductive polymer membrane including a bonded proton conductive polymer, the polymer polymer is excellent in long-term stability and improved in chemical durability and mechanical strength, compared to the conventional phosphoric-doped conductive polymer membrane, and manufactured using the conductive polymer membrane. The fuel cell can ensure high stability and high cell performance during operation.

Description

POLYMER ELECTROLYTE HAVING CHEMICALLY BONDED PHOSPHORIC ACID GROUP, PREPARIONG METHOD OF THE SAME, AND MEMBRANE ELECTRODE ASSEMBLY AND FUEL CELL USING THE SAME}

The present application relates to a polymer electrolyte having a chemically bonded phosphate group, a method of manufacturing the same, a conductive polymer membrane including the polymer electrolyte, and a membrane-electrode assembly using the same and a fuel cell including the same.

A fuel cell is a power generation system that converts energy generated by reacting fuel and oxidant directly into electrical energy. Recently, along with environmental problems, exhaustion of energy sources, and commercialization of fuel cell vehicles, there is an urgent need for the development of high-performance fuel cells with high energy efficiency and operation at high temperatures and reliability. In addition, in order to increase the efficiency of the fuel cell as described above, development of a polymer membrane that can be used at a high temperature is also required.

The fuel cell is mainly a molten carbonate electrolyte fuel cell operating at a high temperature (500 to 700 ° C.), a phosphate electrolyte fuel cell operating at around 200 ° C., an alkaline electrolyte fuel cell and a polymer electrolyte type operating at room temperature to about 100 ° C. It is divided into a fuel cell.

Among the fuel cells as described above, the polymer electrolyte fuel cell is a future clean energy source that can replace fossil energy, and has high power density and energy conversion efficiency. In addition, since it can operate at room temperature and can be miniaturized and sealed, it can be widely used in fields such as pollution-free automobiles, household power generation systems, mobile communication equipment, medical equipment, military equipment, and space business equipment.

Such a polymer electrolyte fuel cell is a direct methanol fuel cell (Proton Exchange Membrane Fuel Cell: PEMFC) that uses hydrogen gas as a fuel and a direct methanol fuel cell that supplies liquid methanol directly to the anode. Methanol Fuel Cell (DMFC).

The PEMFC is a power generation system for producing direct current electricity from an electrochemical reaction between hydrogen and oxygen, and the basic structure of the PEMFC is illustrated in FIG. 1 (reference: Korean Patent Registration No. 10-0524819).

That is, PEMFC has a structure in which a proton conductive polymer film 11 is interposed between an anode and a cathode. Specifically, the PEMFC has a thickness of 50 to 200 μm, and a proton conductive polymer membrane 11 made of a solid polymer electrolyte, each support layer 14 and 15 for supplying a reactor, and an oxidation / reduction reaction of the reactor. An anode and a cathode (hereinafter referred to collectively referred to as a "gas diffusion electrode") consisting of each of the catalyst layers 12 and 13 in which this occurs, a carbon plate 16 having a groove for gas injection and performing a current collector function It consists of). In the gas diffusion electrode of the PEMFC, the catalyst layers 12 and 13 are formed on the support layers 14 and 15, respectively, wherein the support layers 14 and 15 are made of carbon cloth or carbon paper, and a reactive gas and a proton conductive polymer membrane The water to be delivered to (11) and the water produced as a result of the reaction are surface-treated for easy passage.

In the PEMFC having the structure as described above, an oxidation reaction occurs at the anode while hydrogen is supplied as a reactive gas, and hydrogen molecules are converted into hydrogen ions and electrons, and the converted hydrogen ions are transferred to the cathode through the proton conductive polymer membrane 11. Delivered.

 In the cathode, a reduction reaction occurs in which oxygen molecules receive electrons and are converted into oxygen ions, and the generated oxygen ions react with the hydrogen ions transferred from the anode and are converted into water molecules. Proton-conducting polymer membranes for fuel cells are electrically insulators, but act as mediators for transferring hydrogen ions from the cathode to the anode during cell operation, and at the same time separate fuel gas or liquid from oxidant gas.

Therefore, the proton-conducting polymer membrane for fuel cells should have excellent mechanical properties and electrochemical stability, and the mechanical properties as a conductive membrane, thermal stability at operating temperature, manufacturability as a thin membrane to reduce resistance, and a small expansion effect when containing liquid. Requirements must be met.

Such polymer electrolyte fuel cells offer high power density and efficiency in a variety of applications such as electric vehicles, portable electronics, and residential power generation, while the emission is almost zero, which is of practical interest. Do.

The most commonly used PEMFCs at present are perfluorinated copolymers such as Nafion® which have good mechanical and chemical stability and good quantum conductivity. Polymer electrolyte membranes such as Nafion® require water and maintain their quantum conductivity. The water absorption, diffusion coefficient and electron-osmotic drag and quantum conductivity of the membrane are correlated and strongly influenced by the operating conditions of the cell. However, the Nafion? Membranes have a big disadvantage: the water in the membrane is constantly removed by the flowing gas in contact with the membrane, resulting in very high costs and loss of conductivity when operating at high temperatures for their future potential applications. Thus, although the high temperature operation of PEMFCs has a number of important advantages, such as higher system efficiency, better water management and prevention of catalyst poisoning by carbon monoxide, Nafion? To maintain sufficient hydration of the membrane, PEMFCs are usually maintained at temperatures below 100 ° C. Nafion? Since the proton conductivity of the membrane is dependent on the dissociation of protons from ion exchange groups in water, they must be well hydrated to obtain optimal performance. However, at temperatures above the boiling point of water (100 ° C), Nafion? Dehydration of the membrane leads to an increase in the internal resistance of the PEMFC, which drastically reduces the performance of the cell.

Recently, PEMFC has focused on developing PEMFCs that operate above 90 ° C. There are several important reasons for operating at higher temperatures: (1) the electrochemical motion for both electrode reactions is improved, (2) water management can be simplified because only a single phase of water is considered, and (3) the above The cooling system is simplified because of the elevated temperature gradient between the fuel cell stack and the coolant, (4) waste heat can be regenerated as a practical energy source, and (5) the CO tolerance is significantly increased. do. It is therefore possible to use low quality reformed hydrogen in fuel cells.

Most of the conventional phosphoric acid based system membranes have been doped with phosphoric acid. Polybenzimidazole (PBI) -Nafion? The composite membrane was also one of the phosphoric acid based system membranes. The membrane had good oxidative stability up to 300 ° C. and high quantum conductivity at the same temperature. However, the quantum conductivity has been shown to decrease gradually because phosphoric acid is outside the PBI. In another case, the Nafion® / heteropolyacid (HPA) composite membrane exhibited successful high quantum conductivity, while HPA leached from PEMFC. Conventional phosphate lobster films have failed to operate PEMFC at high temperatures because it is a doping system with phosphoric acid or soluble polyacids when operating for a long time. That is, the conventional polymer electrolyte membranes doped with phosphoric acid failed to secure both chemical durability and mechanical strength. PBI / H ₃ PO ₄ doping membrane, which is widely used as PEMFC electrolyte membrane for high temperature (100 ~ 200 ℃), is a doped membrane instead of chemically bonded phosphate group. It has a problem of deterioration, and under humidification conditions, the phosphate groups are washed away with water, thereby having a problem of deterioration.

The present inventors, when manufacturing a conductive polymer membrane using a conductive polymer electrolyte in which a phosphate group is chemically bonded, excellent in long-term stability compared to the conventional conductive polymer doped with phosphoric acid, both chemical durability and mechanical strength is improved, the conductive The present invention was completed by discovering that high stability and high cell performance can be secured while operating a fuel cell manufactured using a polymer membrane.

Accordingly, the present application is to provide a polymer electrolyte having a chemically bonded phosphoric acid group, a method of manufacturing the same, a conductive polymer membrane including the polymer electrolyte, and a membrane-electrode assembly using the same and a fuel cell including the same.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, one aspect of the present application provides a polymer electrolyte comprising a hydrocarbon-based proton conductive polymer having a pendant chain containing a chemically bonded phosphoric acid group.

Another aspect of the present application provides a proton conductive polymer membrane comprising the polymer electrolyte.

Another aspect of the present invention, a method for producing a polymer electrolyte, comprising the steps of: obtaining a reaction mixture comprising a hydrocarbon-based proton conductive polymer, a linker compound, a phosphate source compound and a transition metal-containing catalyst; And reacting the reaction mixture in a microwave reactor to obtain a hydrocarbon-based proton conducting polymer having a pendant chain including a chemically bound phosphoric acid group.

Another aspect of the present application provides a fuel cell comprising the polymer electrolyte.

Another aspect of the present application provides a membrane-electrode assembly including the proton conductive polymer membrane.

Another aspect of the present disclosure provides a fuel cell comprising the membrane-electrode assembly.

According to the present invention, when a proton conductive polymer membrane is manufactured using a polymer electrolyte including a proton conductive polymer having a phosphate group chemically bonded, it is superior in long-term stability and has excellent chemical durability and mechanical strength as compared with a conventional polymer layer doped with phosphoric acid. All are improved, it is possible to ensure high stability and high battery performance during operation of the fuel cell produced using the conductive polymer membrane. The proton conductive polymer membrane according to the present invention exhibits high and stable conductivity in a high temperature range (100 ° C. or higher, for example, 100 to 200 ° C., or 120 to 180 ° C.), thereby reducing the cost of developing and manufacturing PEMFC using a high temperature electrolyte membrane. useful. When the PEMFC is operated at high temperature, the battery can be operated with a small amount of catalyst, thus reducing the amount of expensive catalyst used, and reducing the excess heat generated during the operation. It is very likely that it can be applied to the actual industry. In addition, the proton conductive polymer membrane according to the present application can be used even in a humidified state.

1 is a diagram schematically showing a general structure of a proton conductive polymer membrane fuel cell (PEMFC).
Figure 2 is a schematic diagram showing the proton conduction mechanism of phosphoric acid in one embodiment of the present application.
3 is an FT-IR spectrum of a proton conductive polymer membrane according to one embodiment of the present application.
Figure 4 is a ³¹ P-NMR spectrum of the proton conductive polymer film in one embodiment of the present application.
Figure 5 is a graph showing the thermal stability (TGA) of the proton conductive polymer membrane in one embodiment of the present application.
6 is a graph showing the ion conductivity with respect to the temperature of the proton conductive polymer membrane in one embodiment of the present application.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments and embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

Throughout this specification, it is to be understood that when a layer or member is " on " another layer or member, it is not only the case where a layer or member is in contact with another layer or member, Or < / RTI > another member is present. In addition, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless otherwise stated.

As used throughout this specification, the terms “about”, “substantially”, and the like, are used at, or in the vicinity of, numerical values when manufacturing and material tolerances inherent in the meanings indicated are given, and an understanding of the invention Accurate or absolute figures are used to help prevent unfair use by unscrupulous infringers. As used throughout this specification, the term “step of” or “step of” does not mean “step for”.

One aspect of the present disclosure provides a polymer electrolyte comprising a hydrocarbon-based proton conductive polymer having a pendant chain including a chemically bonded phosphoric acid group.

The phosphoric acid (H ₃ PO ₄ ) is an almost ideal proton conductor with a melting point (T _m ) of 42 ° C. and pure phosphoric acid is a high viscous liquid with extended intermolecular hydrogen bonds. In contrast to water, conductivity is not affected by the degree of hydration. In the case of pure phosphoric acid, the proton conductivity of the additive is easily shifted by the diffusion of the structure, for example, the proton moves between the types of phosphate and between the reorientation of the phosphate. That is, phosphoric acid shows a very high degree of self-dissociation, and protons migrate between various types of phosphates such as H ₂ PO ₄ ⁻ , H ₃ PO ₄ , H ₄ PO ₄ ⁺ . The quantum conductivity mechanism of the phosphoric acid is shown in FIG. 2.

The polymer electrolyte may include an organic hydrocarbon-based proton conductive polymer having a side group including a chemically bonded inorganic phosphate group.

In an exemplary embodiment, the side group may include a linker bonded to the main chain of the hydrocarbon-based proton conductive polymer and a phosphate group chemically bonded to the linker, but is not limited thereto.

In an exemplary embodiment, the linker is an alkylene group having 1 to 20 carbon atoms,-(CH ₂ ) _n -NR- (wherein n is an integer of 1 or more, and R is Is hydrogen, or Alkylamine group, an ester group having 1 to 20 carbon atoms, a ketone group having 1 to 20 carbon atoms, an amide group having 1 to 20 carbon atoms, and a siloxane group, but are not limited thereto. . For example, the linker may have one or more carbon atoms, for example, 1 to 20, or 1 to 15, 1 to 10, but is not limited thereto. For example, the siloxane group may be represented by the following formula, but is not limited thereto.

Wherein R ¹ and R ² are each independently hydrogen, OH, halogen, an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, x is an integer of 0 to 20, y is 0 or 1

In an exemplary embodiment, the hydrocarbon-based proton conductive polymer, polyaniline, polypyrrole, polyacetylene, polyacene, polythiophene, polyalkylthiophene, poly (p-, having side groups including chemically bonded phosphoric acid groups Phenylene), polyphenylene, polyphenylene sulfide, polyphenylenevinylene, polyfuran, polyacetylene, polyserenophene, polyisothianaphthene, polythiophenvinylene, polyperinaphthalene, polyanthracene, poly Naphthalene, polypropylene, polyazulene, derivatives thereof and copolymers thereof may be selected from the group consisting of, but is not limited thereto. For example, polyaniline (Pani) has many advantages such as chemical and mechanical stability, easy synthesis from relatively inexpensive monomers, and cost competitiveness. In this regard, polyaniline has attracted much attention as a promising material for the display of battery electrodes, electrical and optical devices, and electronic chromium.

In one embodiment, the hydrocarbon-based proton conductive polymer may include a monomer represented by Formula 1, but is not limited thereto.

[Formula 1]

In the above formula, n may be an integer of 1 or more, for example, n may be 1 to 20, or n may be 1 to 15, or n may be 1 to 10, or n may be 1 to 6, but is not limited thereto.

In an exemplary embodiment, the hydrocarbon-based proton conductive polymer may be crosslinked, but is not limited thereto. The proton conductive polymers are crosslinked with each other by crosslinking through side groups included therein to further improve high temperature stability and chemical durability as the polymer electrolyte, and further improve both chemical durability and mechanical strength when manufacturing the conductive polymer membrane using the same. I can do it.

Another aspect of the present application provides a proton conductive polymer membrane comprising the polymer electrolyte. The performance of the polymerizer can be improved by increasing the content of chemically bound phosphoric acid, and thus can be used for fuel cell applications at high temperatures. The proton conductive polymer membrane may be a membrane including an organic hydrocarbon-based proton conductive polymer having a side group including a chemically bonded inorganic phosphate group.

In an exemplary embodiment, the thickness of the proton conductive polymer membrane may be 1 μm to 150 μm, but is not limited thereto.

In one embodiment, the polymer may be a polyaniline having a side group including a chemically bonded phosphoric acid group, the polyaniline may provide excellent performance at high temperature and stable elasticity as a polymer electrolyte membrane of a fuel cell. In one embodiment, the polyaniline may be introduced by chemical bonding to the side groups as a proton conductor through the Buchwald reaction using a microwave at a high temperature. The polyaniline polymer film never loses a phosphate group, and can maintain high proton conductivity and battery performance by using a phosphate group at a high temperature. The polymer membrane has many advantages including excellent performance, excellent thermal and mechanical stability, low cost, and the like. The amine linker and the phosphate group may be chemically bonded to the side group of the polyaniline to impart proton conductivity and thus may be used at a high temperature. Conventional polyaniline solutions have a rapid gelation at concentrations of 5 to 6 wt%, so that the application of the polyaniline solution has been limited to low concentrations. In addition, retention of conventional polyaniline mechanical strength, thin separators and chemical stability is required. Although conventional polyaniline is stable in water, it has been dissolved or partially dissolved in many organic solutions such as N -methyl-2-pyrrolidone (NMP), dimethylformamide (DMF) and tetrahydrofuran (THF). Thus, unless treated in any way, conventional polyaniline membranes cannot be used in the filtration of these organic solutions. As a result, the application or casting of polyaniline based conductive polymer films has been difficult in many studies. However, the problem can be overcome by: (1) crosslinking the polyaniline membrane to induce chemical stability, and (2) the mechanical stability of the polyaniline membrane can be improved by preparing from high molecular weight polyaniline. Thus, in one embodiment of the present application, in the case of forming a proton conductive polymer membrane using polyaniline having an amine linker and a phosphate group chemically bonded to the side group, by cross-linking between the phosphate groups contained in the side group in the conductive polymer membrane The polyaniline is crosslinked to form a more stable conductive polymer film, and thus may have high and stable conductivity and high temperature stability at high temperature (100 ° C. or higher, for example, 100 to 200 ° C., or 120 to 180 ° C.).

The proton conductive polymer membrane may be prepared by dissolving or dispersing the polymer electrolyte according to the present application in an appropriate organic solvent and then coating the appropriate substrate. The substrate may include teflon, but is not limited thereto. The organic solvent is, for example, N-methyl-2-pyrrolidone (NMP), 4-methyl piperidine (4-methyl piperidine, 4MP), dimethylformamide DMF), dimethyl acetamide (DMA), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), acetone, methyl ethyl ketone (MEK), tetramethylurea ( tetramethylurea, trimethyl phosphate, butyrolactone, isophorone, carbitol acetate, methyl isobutyl ketone, N-butyl acetate ), Cyclohexanone, diacetone alcohol, diisobutyl ketone, ethyl acetoacetate, glycol ether, propylene carbonate, ethylene carbonate (ethy lene carbonate, dimethylcarbonate, diethylcarbonate, or mixtures thereof, but is not limited thereto.

Another aspect of the present application is to obtain a reaction mixture comprising a hydrocarbon-based proton conductive polymer, a linker compound, a phosphate group source compound and a transition metal-containing catalyst; And reacting the reaction mixture in a microwave reactor to obtain a hydrocarbon-based proton conducting polymer having a pendant chain including a chemically bound phosphoric acid group.

The phosphate group source compound refers to a compound containing a phosphate group or a phosphorus-containing group, and means a compound capable of providing a phosphate group chemically bonded to the side group of the hydrocarbon-based proton conductive polymer prepared by the reaction.

The phosphate source compound is, for example, 1,1'-bis (diphenylphosphino) -ferrocene (1,1'-bis (diphenylphosphino) -ferrocene), ammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ) , Ammonium dihydrogen phosphate ((NH ₄ ) H ₂ PO ₄ ), ammonium phosphate ((NH ₄ ) ₃ PO ₄ ), diphosphorous pentoxide (P ₂ O ₅ ), phosphoric acid (H ₃ PO ₄ ), lithium phosphate (Li ₃ PO ₄ ), lithium phosphate (Li ₂ HPO ₄ ), dihydrate lithium phosphate (LiH ₂ PO ₄ ), lithium ammonium phosphate (Li ₂ NH ₄ PO ₄ ), lithium ammonium phosphate (Li (NH ₄ ) ₂ PO ₄ ) And mixtures thereof, but is not limited thereto.

In an exemplary embodiment, the linker compound is an alkylene group having 1 to 20 carbon atoms,-(CH ₂ ) _n -NR _1- (wherein n is an integer of 1 or more, R ₁ is hydrogen, or It may be a compound containing an alkylamine group represented by C1 to C20), an ester of 1 to 20 carbon atoms, a ketone group of 1 to 20 carbon atoms, an amide group of 1 to 20 carbon atoms, or a siloxane group, It is not limited. For example, in-(CH ₂ ) _n -NR ₁ -representing the linker, n is an integer of 1 or more, for example, n is 1 to 20, or n is 1 to 15, or n is 1 to 10, Or n may be 1 to 6, but is not limited thereto. Wherein the-(CH ₂ ) _n -moiety comprises alkylene and isomers thereof.

In an exemplary embodiment, the transition metal-containing catalyst is iron (Fe), cobalt (Co), nickel (Fe), ruthenium (Ru), rhodium (Rh), platinum (Au), palladium (Pd) and these It may include one selected from the group consisting of, but is not limited thereto.

In an exemplary embodiment, the reaction temperature may be 100 ° C. or more, for example, 100-200 ° C., but is not limited thereto.

Another aspect of the present application provides a fuel cell comprising the polymer electrolyte.

Another aspect of the present application provides a membrane-electrode assembly including the organic / inorganic proton conductive polymer membrane.

Another aspect of the present disclosure provides a fuel cell comprising the membrane-electrode assembly.

The fuel cell is an electrochemical device that directly converts the chemical energy of a fuel into electrical energy and provides a clean and very efficient source of electrical energy, potentially electric vehicle power. Like a battery, a fuel cell consists of two electrodes separated by an electrolyte made of a thin polymer membrane. But unlike batteries, it continues to generate electricity for as long as fuel flows through it. As a result, fuel cells were often regarded as one of the future advanced energy technologies. A schematic representation of the fuel cell operating principle is shown in FIG. 1. As shown in Fig. 1, the PEMFC operates as a polymer electrolyte membrane in which the fuel (hydrogen) is separated from an oxidant (air or oxygen).

Hereinafter, the present invention will be described in more detail with reference to Examples, but is not limited thereto.

Reagents

Fully-reduced leucoemeraldine powder, 1,1'-bis (diphenylphosphino) -ferrocene (1,1'-bis (diphenylphosphino) -ferrocene), sodium t-butoxide, bis (Dibenzylideneacetone) dipalladium (0) ((dibenzy-lideneacetone) dipalladium (0)) and 3-bromopropylamine were purchased from Aldrich and used without further purification. N-methyl-2-pyrrolidinon (NMP), 4-methyl piperidine (4MP) and dimethylformamide (DMF) used the highest quality and additional Used without purification.

PhosPani  Preparation of Polymer Electrolyte

The "PhosPani polyelectrolyte" means a polyaniline having a side group including a chemically bonded phosphoric acid group. 0.86 g of fully reduced polyaniline (leucoemeraldine), 0.17 g of 1,1′-bis (diphenylphosphino) -ferrocene, 0.51 g of 3-bromopropylamine, 0.1 g of sodium t-butoxide and bis (dibenzylideneacetone 0.17 g of dipalladium was added into a microwave vial. The microwave vial was sealed and 3 mL of anhydrous DMF was added. The microwave vial was reacted in a microwave reactor at 170 ° C. for 2 hours to synthesize PhosPani polymer electrolyte.

A reasonable mechanism for this embodiment is the catalytic cycle of the modification. Pd (0) species is an active catalyst and the catalytic cycling involves the oxidative addition of the aryl halide, the coordination and deprotonation of the amine, and the reductive removal of the N-aryl product. Seems to do.

PhosPani  Preparation of Polymer Electrolyte Membrane

The PhosPani polymer electrolyte synthesized in Example 1 was added to a solution in which NMP and 4MP were mixed and dissolved with stirring for 24 hours. The solution was cast on a teflon plate in a 150 ° C. vacuum oven for 24 hours to prepare a PhosPani polymer electrolyte membrane. The PhosPani polymer electrolyte membrane prepared above was immersed in deionized water (DI Water) to remove the residue, and washed several times with NMP to remove the remaining polyaniline.

< Characterization of PhosPani Polymer Electrolyte Membrane>

FT-IR, ³¹ P-NMR and TGA were used to observe the chemical structure analysis and thermal stability of the PhosPani polymer electrolyte membrane. The membrane exhibited good performance at high temperatures through proton conductivity.

One. Chemical structure analysis

FT - IR  Spectroscopic analysis

The FT-IR spectrum of the PhosPani polymer electrolyte membrane is shown in FIG. 3. As shown in FIG. 3, the PhosPani polyelectrolyte membrane contained a peak at 3400 cm ⁻¹ due to PNH binding, and a low peak was observed at 2852 cm ⁻¹ due to CH stretching. This is due to the remaining benzoid structure, which does not change CH stretching. In addition, the peaks in the 1600-1450 cm ^-1 region were due to aromatic ring breathing, NH deformation and CN stretching, and the strong bands in the 1320-1260 cm ^-1 region were due to PNC bonds. . The IR peak of the PhosPani polymer electrolyte membrane was 1260 to 1195 cm ⁻¹ corresponding to the phosphorylated amine group. These facts indicate that the chemical reaction was achieved between the phosphate group and the amine group as well as the back bone and the functional group.

Based on the FT-IR spectrum, the chemical structure of the PhosPani polymer electrolyte membrane is shown in Figure 3 (right) and the following formula:

 The presence of the amine group of polyaniline (Pani) in the PhosPani polymer electrolyte membrane can induce an ionic crosslink between 3-bromopropylamine and the amine group through the observed results.

³¹ P- NMR  Spectroscopic analysis

³¹ P-NMR spectrum of the PhosPani polymer electrolyte membrane is shown in FIG. 4. The ³¹ P-NMR spectra were based on 85% H ₃ PO ₄ (δ = 0). As shown in FIG. 4, the peak at δ = 0.402 ppm is due to the activated phosphorylated amine group, which shows that the phosphate group is chemically bound to the amine group as well as the proton conduction mechanism is very active. The peak at δ = −10.656 ppm is also due to the chain ends of the amino phosphate and the peak at δ = −22.920 ppm is due to the phosphorylated amine groups affected from the benzene ring.

2. Thermal stability

The TGA graph of the PhosPani polymer electrolyte membrane and the weight loss due to hydrocarbon backbone decomposition are shown in FIG. 5. As shown in FIG. 5, the hydrocarbon backbone of the polyaniline (Pani) membrane was not decomposed at a temperature below 230 ° C., whereas the PhosPani polymer electrolyte membrane was able to maintain its structure up to 450 ° C. FIG. Thus, the PhosPani polymer electrolyte membrane can withstand temperatures above 400 ° C. and can be safely used at high temperatures. The result is that, unlike the pure polyaniline (Pani) membrane, the PhosPani polymer electrolyte membrane was crosslinked.

3. Proton Conductivity

Proton conductivity with temperature was measured at intervals of 20 ° C. in the region of 40 ° C. to 180 ° C. of the PhosPani polymer electrolyte membrane. Relative humidity was accurately measured using a measuring device, and the graph of ion conductivity according to the temperature is shown in FIG. 6. As shown in FIG. 6, it showed a relatively low conductivity at 40 ° C. because the activation energy for the chemical reaction was too large. However, as the temperature rose, the activation energy fell further. Therefore, the conductivity slowly increased and remained very stable up to 180 ° C. The results indicate that the PhosPani polymer electrolyte membrane no longer requires water molecules and that the phosphate groups conduct protons well at high temperatures.

Hereinbefore, the present invention has been described in detail with reference to the embodiments and examples, but the present invention is not limited to the above embodiments and embodiments, and may be modified in various forms, and is commonly used in the art within the technical spirit of the present application. It is evident that many variations are possible by those of skill in the art.

11: proton conductive polymer membrane
12, 13: oxidation / reduction catalyst layer
14, 15: support layer
16: carbon plate

Claims (15)

A polymer electrolyte comprising a hydrocarbon-based proton-conducting polymer having a pendant chain including a chemically bonded phosphoric acid group, wherein the hydrocarbon-based proton-conducting polymer includes a monomer represented by Formula 1 below:
[Formula 1]

Wherein n is an integer of 1 or more.
delete delete delete delete The method of claim 1,
The hydrocarbon-based proton conductive polymer is crosslinked.
A proton conductive polymer membrane comprising the polymer electrolyte according to claim 1.
The method of claim 7, wherein
The proton conductive polymer membrane has a thickness of 1 μm to 150 μm.
Obtaining a reaction mixture comprising a hydrocarbon-based proton conducting polymer, a linker compound, a phosphoric acid source compound and a transition metal-containing catalyst; And
Reacting the reaction mixture in a microwave reactor to obtain a hydrocarbon-based proton conductive polymer having a pendant chain comprising chemically bound phosphoric acid groups:
A method for producing a polymer electrolyte comprising a.
The method of claim 9,
The linker compound is an alkylene group having 1 to 20 carbon atoms,-(CH ₂ ) _n -NR _1- (wherein n is an integer of 1 or more, R ₁ Is hydrogen, or A polymer containing an alkylamine group represented by C 1 -C 20 alkyl), an ester group of 1-20 carbon atoms, a ketone group of 1-20 carbon atoms, an amide group of 1-20 carbon atoms, or a siloxane group Manufacturing method.
The method of claim 9,
The transition metal-containing catalyst is selected from the group consisting of iron (Fe), cobalt (Co), nickel (Fe), ruthenium (Ru), rhodium (Rh), platinum (Au), palladium (Pd) and combinations thereof The method comprising the step of producing a polymer electrolyte.
The method of claim 9,
The reaction temperature is 100 ℃ to 200 ℃, a method for producing a polymer electrolyte.
A fuel cell comprising the polymer electrolyte according to claim 1.
Membrane-electrode assembly comprising a proton conductive polymer membrane according to claim 7.
A fuel cell comprising the membrane-electrode assembly according to claim 14.

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