KR20160024137A - Polymer electrolyte membrane, water electrolysis apparatus, fuel cell and fuel cell system containing the same - Google Patents

Abstract

The present invention relates to an ion exchangeable polymer electrolyte membrane, a water electrolysis apparatus, a fuel cell, and a fuel cell system comprising the same and, more specifically, to a polymer electrolyte membrane which comprises a polymer (inorganic acid and metal oxide) having a covalently cross-linked repetitive structure, and thus having high thermal stability, thereby having excellent electrochemical performance such as ion conductivity, ion exchange capacity, and the like at the high temperature, and having improved mechanical matter properties such as chemical durability, tensile strength, and the like, to a water electrolysis apparatus using the electrolyte membrane, to a fuel cell, and to a fuel cell system comprising the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer electrolyte membrane, a water electrolysis apparatus, a fuel cell, and a fuel cell system including the electrolyte membrane,

The present invention relates to an ion exchangeable polyelectrolyte membrane, a water electrolysis apparatus, a fuel cell, and a fuel cell system including the same, and more particularly, to a fuel cell system including a polymer having a covalent crosslinked repeating structure (and inorganic acid and metal oxide) , A polymer electrolyte membrane having high thermal stability and excellent in electrochemical performance such as ion conductivity and ion exchange capacity even at a high temperature and improved mechanical properties such as chemical durability and tensile strength, and a water electrolysis apparatus using the electrolyte membrane, a fuel cell and the like To a fuel cell system.

Ion exchangeable polymer electrolyte membranes are widely used as electrolysis (water electrolysis) of water and ion exchange membranes (electrolyte membranes) such as fuel cells. The electrolysis (water electrolysis) apparatus of water is a device for producing hydrogen and oxygen by electrochemically decomposing water, and it is attracting attention as a hydrogen production technology due to high energy efficiency. Conversely, fuel cells are environmentally friendly power generation systems that generate electricity by electrochemically reacting hydrogen and oxygen. This is considered to be one of the new energy technologies because of its simple and efficient energy conversion stage compared to internal combustion engines. Particularly, a fuel cell using a solid polymer electrolyte membrane is notable for its merits such as miniaturization and light weight due to a simple structure.

A solid polymer fuel cell (PEFC) generally has a membrane-electrode assembly (MEA) including a solid polymer electrolyte membrane, a catalyst layer bonded to both sides of the electrolyte membrane, and a gas diffusion layer bonded to the outside of the catalyst layer. A separator is disposed in the membrane-electrode assembly (MEA). Further, a gas flow path for supplying the fuel gas or the oxidizing agent gas is formed in the contact portion of the membrane-electrode assembly (MEA) and the separator or in the separator. At this time, fuel gas such as hydrogen or methanol is supplied to one electrode (fuel electrode), and oxidant gas containing oxygen such as air is supplied to the remaining electrode (oxygen electrode) to generate electricity.

As the polymer electrolyte membrane for exchanging ions in the fuel cell and the water electrolytic unit, the Nafion (manufactured by Dupont), which is a perfluorocarbon membrane, is generally used for commercialization. However, Nafion membranes are complicated and expensive to manufacture. In addition, it has been pointed out that the Nafion membrane has poor electrochemical performance such as ionic conductivity at a high temperature of 80 캜 or more.

Accordingly, Japanese Patent Laid-Open Publication No. 06-93114 proposes a method for producing an electrolyte membrane based on a sulfonated aromatic polyether ketone. However, if the degree of sulfonation is increased to increase the ion exchangeability, the membrane is disadvantageously deteriorated due to the swelling phenomenon, which makes it difficult to handle, the mechanical properties such as durability and tensile strength are low, and the thermal stability is unsatisfactory have. Further, in Japanese Patent Application Laid-Open No. 11-329062, as a polymer for the production of an electrolyte membrane, use of a polymer having two or more different fluorine-containing unit blocks, one of which has a sulfonic acid group, However, it is pointed out that a vinyl ether monomer is used as a unit block having a sulfonic acid group, thereby deteriorating the thermal stability.

In order to compensate for these problems, Korean Patent Publication No. 10-0964238 discloses a process for producing a polyurethane foam by using a sulfonated aromatic polyether ether ketone, 1,4-diiodobutane, Which has excellent electrochemical properties such as hydrogen ion conductivity and ion exchange capacity, and improved thermal stability and mechanical strength. However, there are problems in performance degradation and chemical durability caused by decomposition of a film due to free radicals generated by an electrochemical reaction.

As described above, the conventional polymer electrolyte membrane is vulnerable to free radicals generated by an electrochemical reaction.

1. Japanese Unexamined Patent Publication No. 06-093114 (Apr. 2. Japanese Unexamined Patent Publication No. 11-329062 (November 30, 1999) 3. Korean Patent Registration No. 10-0964238 (Jun. 16, 2010)

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a polymer electrolyte membrane which is free from radical scavengers and which is a radical scavenger, By including a polymer having an excellent chemical durability by protecting an electrolyte membrane from a free radical and having a unit block crosslinked in the molecule, it has high thermal stability and is excellent in electrochemical properties such as ion conductivity and ion exchange capacity even at a high temperature, , A fuel cell, and a fuel cell system including the electrolyte membrane, a water electrolysis apparatus using the electrolyte membrane, a fuel cell, and a fuel cell system including the same.

The present invention also relates to a polymer electrolyte membrane having improved thermal stability, mechanical properties and chemical durability by further including an inorganic acid, a method for producing the membrane, and a water electrolysis apparatus using the electrolyte membrane, a fuel cell, and a fuel cell system And the like.

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

In order to achieve the above object, the present invention provides a polymer electrolyte membrane comprising a polymer having a repeating unit represented by the following Chemical Formula, further comprising an inorganic acid and a metal oxide.

[Chemical Formula]

(Wherein R is hydrocarbon and m, n, p and q are an integer of 1 or more).

In addition, the polymer electrolyte membrane according to the present invention preferably further comprises a metal oxide carrying inorganic and inorganic acids. When the metal oxide carrying the inorganic acid and inorganic acid is added, the polymer electrolyte membrane is protected from free radicals generated during the electrochemical reaction Thereby improving the chemical durability of the polymer film and further enhancing thermal stability, mechanical properties and chemical durability by inorganic acids.

In addition, the present invention is a method for producing a polymer electrolyte membrane according to the present invention, which comprises the steps of: preparing a metal oxide on which a carbonate metal and an inorganic acid are supported together, and a method for producing a polymer electrolyte membrane, to provide.

[Process for producing a metal oxide supported with a carbonate metal and an inorganic acid]

(1) Step 1 of carrying a metal carbonate to the metal oxide

(2) a second step of sintering the metal oxide carrying the carbonate metal

(3) Third step of supporting inorganic acid on sintered metal oxide

(4) the fourth step of sintering the metal oxide carrying the inorganic acid

[Manufacturing Process of Polymer Electrolyte Membrane]

(1) Step 1 of introducing a sulfone group (-SO ₃ H) into the polymer

(2) a step of introducing a sulfinic group (-SO ₂ ) into the sulfonated polymer

(3) a third step of partially reducing the sulfurized polymer so that a sulfinic group (-SO ₂ ) and a sulfonic acid group (-SO ₂ M; M is a metal) are present in the polymer

(4) mixing the partially-reduced polymer with a solvent, and then adding and stirring the cross-linking agent to prepare a casting solution; and

(5) a fifth step of coating the casting solution to prepare a film

(6) Step 6 of replacing H ⁺ of inorganic acid with metal

(7) a seventh step of replacing the above-prepared film pingi sulfonic (-SO ₂₎ to the sulfonic group (-SO ₃ H)

The method for producing a polymer electrolyte membrane according to the present invention may further include a step of adding a metal oxide on which a carbonate metal and an inorganic acid are supported together before proceeding to the fourth step, specifically between the third step and the fourth step And an inorganic acid. In addition, step a) to partial reduction so that the third step is set sodium group (-SO ₂ Na) sulfonic acid is present in the polymer pinhwa; And a step b) of replacing the sodium sulfonate group (-SO ₂ Na) with a lithium sulfonate group (-SO ₂ Li).

In addition, the present invention provides a water electrolysis apparatus including the polymer electrolyte membrane according to the present invention, a fuel cell, and a fuel cell system including the fuel cell.

According to the present invention having the above-described structure, the unit block having an ion-exchange unit is ion-exchangeable and further includes a unit block cross-linked in the molecule, so that the ionic conductivity and ion exchange capacity And the mechanical properties such as tensile strength are improved.

In addition, when a metal oxide containing a carbonate metal and an inorganic acid together with an inorganic acid is further included, the thermal stability, mechanical properties and chemical durability are further improved.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

FIGS. 1 and 2 are graphs showing the results of FT-IR analysis of an electrolyte membrane according to an embodiment of the present invention.
3 is a graph showing a result of thermal mass analysis of an electrolyte membrane according to an embodiment of the present invention.
4 is a graph showing ionic conductivity of an electrolyte membrane according to an embodiment of the present invention.
5 is a graph showing ion exchange capacity and water content of an electrolyte membrane according to an embodiment of the present invention.
6 is a graph showing a CV curve of a membrane-electrode assembly (MEA) manufactured according to an embodiment of the present invention.
7 is a graph of current-voltage of a water-electrolytic cell manufactured according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the following description. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Hereinafter, the present invention will be described in more detail.

The polymer electrolyte membrane according to the present invention is prepared from a material containing at least a polymer, wherein the polymer comprises a unit block A having an ion-exchange group and a unit block B having a reactive group according to the present invention, Which are cross-linked with each other. Specifically, the polymer has a repeating unit represented by the following formula (1).

[Chemical Formula 1]

(Wherein A is a unit block having an ion-exchange group, B is a unit block having a reactive group, and m, n, p and q are integers of 1 or more).

The polymer is preferably selected from the group consisting of polyetheretherketone, polyarylene ether ketone, polysulfone, polyarylene ether sulfone, polyimide, polybenzimidazole, polybenzoxazole, polybenzothiazole, polypyrrolone, Polybenzoxazole-polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol, polyglycerol,

Specifically, the polymer may be prepared by introducing an ion exchanger using the polymer listed above as a starting material, and then, through a crosslinking reaction, a unit block A in which an ion exchanger is introduced into the molecule and a cross- . The ion exchanger of the unit block A may be any functional group having proton conductivity, and includes, for example, a sulfonic acid group, a sulfonimide group, a phosphonic acid group, a carboxylic acid group, and a metal salt thereof Or ammonium salts. In addition, the unit block B has a reactive group for crosslinking, and the reactive group may be a double bond, a triple bond, or an ion existing in the unit block B. In addition, the reactive group may be introduced into the unit block B separately, for example, a sulfin group (-SO ₂ ) by sulfination.

The unit block B may or may not have an ion exchanger and is cross-linked by a reactive group or a covalent bond or an ionic bond. The unit blocks B are preferably mutually covalently crosslinked.

According to a preferred embodiment of the present invention, it is preferable that the polymer has a structure in which hydrocarbons are connected between the unit block B and the unit block B. Specifically, the polymer preferably has a repeating unit represented by the following formula (2).

(2)

Wherein A is a unit block having an ion-exchange group, B is a unit block having a reactive group, R is a hydrocarbon, and m, n, p and q are an integer of 1 or more.

In the above formula (2), R may be selected from hydrocarbons, wherein the hydrocarbons include aliphatic and aromatic hydrocarbons. For example, R in the above formula (2) may be an alkane, an alkene, an alkene, a cycloalkane, an aryl, or the like as a hydrocarbon. Although not particularly limited, R in the above formula (2) is preferably an aliphatic hydrocarbon having 1 to 12 carbon atoms, preferably 4 to 8 carbon atoms.

Further, the polymer may be prepared to have a repeating unit of the above formula (2) by the addition of a crosslinking agent. At this time, R of the formula (2) is introduced by a crosslinking agent, and the crosslinking agent is not particularly limited, but an alkene hydrocarbon having 1 to 12 carbon atoms, preferably 4 to 8 carbon atoms is preferable. As the crosslinking agent, for example, iodine alkene such as 1,4-diiodobutene and the like can be usefully used.

According to the present invention, the unit block A having an ion-exchange group is ion-exchangeable, and the thermal stability is improved by the unit block B which is crosslinked (preferably covalently bonded by a crosslinking agent). Accordingly, the polymer electrolyte membrane according to the present invention has high thermal stability as described above and is excellent in electrochemical characteristics such as ion conductivity even at a high temperature. In addition, the polymer electrolyte membrane according to the present invention has a high water content, is prevented from swelling, and has excellent mechanical properties such as durability and tensile strength.

According to a more preferred embodiment of the present invention, the ion exchanger of the unit block A is a sulfone group (-SO ₃ H) and the reactive group of the unit block B is a sulfinic group (-SO ₂ ) (3).

(3)

(Wherein R is hydrocarbon and m, n, p and q are an integer of 1 or more).

The polymer of the above formula 3 may be obtained on the basis of an aromatic polyether ether ketone. At this time, the aromatic polyetheretherketone is excellent in heat resistance, fatigue resistance, moisture absorption resistance and chemical resistance, and can be highly sulfonated as compared with other polymers, and thus is preferably applied to the present invention.

In the above formulas (1) to (3), m and p in the unit block A may be the same or different, and n and q in the unit block B may be the same or different. Preferably, at least in the formula 3, m = p and n = q. In addition, in the above formulas 1 to 3, the larger m and p are, the more advantageous in ion exchangeability, and the larger the n and q, the better the mechanical properties. In this case, (p): n (q) is preferably 1: 0.2 to 5.0.

The polymer electrolyte membrane according to the present invention can be produced by a coating method such as a casting solution containing at least a material containing at least the above polymer, specifically, a polymer and a solvent.

Further, it is preferable that the polymer electrolyte membrane according to the present invention further comprises a metal oxide containing at least the above-mentioned polymer and carrying inorganic acid and inorganic acid as an additive. According to the present invention, the inorganic acid further improves thermal stability, and has improved mechanical properties such as tensile strength improvement and swelling prevention. The inorganic acid is not particularly limited, but is preferably contained in an amount of 1.0 to 60% by weight based on the total weight of the electrolyte membrane. At this time, if the content of the inorganic acid is less than 1.0% by weight, it is difficult to achieve improved thermal stability and mechanical properties depending on the content of the inorganic acid, and if it exceeds 60% by weight, the water content may be lowered. The inorganic acid is preferably contained in an amount of 1.0 to 40% by weight, more preferably 20 to 30% by weight. Further, the inorganic acid may be one or a mixture of two or more selected from the group consisting of phosphotungstic acid, zirconium phosphate, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid. As the metal reagent used for preventing the leaching of inorganic acid, 1,2-group carbonates on the periodic table can be used.

According to the present invention, in the case of a metal oxide, the chemical durability of the electrolyte membrane can be improved by preventing the decomposition of the membrane due to the free radicals generated in the electrolysis process. The metal oxide is not particularly limited, and is preferably contained in an amount of 0.5 to 10% based on the total weight of the electrolyte membrane. If it is less than 0.5%, it is difficult to expect improvement of chemical durability by metal oxide. If it exceeds 10%, it is difficult to expect the performance as an electrolyte membrane due to reduction of hydrogen ion conductivity of the electrolyte membrane. In order to compensate for the disadvantage of metal ion not having hydrogen ion conductivity, inorganic acid was supported on the support. In order to prevent the inorganic acid from being easily loaded and leached, a metal carbonate was supported on the support. The inorganic acid used herein may be a mixture of one or more selected from the group consisting of phosphotungstic acid, zirconium phosphate, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid. The metal oxide used may be a mixture of one or more of the metal oxides containing two oxygen atoms.

The polymer electrolyte membrane according to the present invention as described above can be produced by the following method, according to a preferred embodiment of the present invention. In the method described below, a sulfone group (-SO ₃ H) is introduced as an ion exchanger, and a sulfinic group (-SO ₂ ) is introduced through partial reduction as a reactive group for crosslinking. However, the polymer electrolyte membrane according to the present invention is not limited to the one produced by the following method.

The polymer electrolyte membrane according to the present invention comprises (1) a step of introducing a sulfone group (-SO ₃ H); (2) Description pingi (-SO ₂₎ introducing step; (3) partial reduction step; (4) a casting solution preparation step; (5) a casting step; And (6) a metal substitution step of H ⁺ of the inorganic acid, and (7) a sulfone group (-SO ₃ H) substitution step.

Also, in the case of a metal oxide to which a carbonate metal and an inorganic acid are added together to be added to a polymer electrolyte membrane, (1) a step of supporting a carbonate metal; (2) sintering; (3) carrying inorganic acid; (4) a sintering step. Each step will be described in detail as follows.

[Manufacturing Process of Polymer Electrolyte Membrane]

(1) Sulfonoxy group (-SO ₃ H) introduction step

First, the polymer of the starting material is reacted with a sulfonating agent to replace and introduce a sulfone group (-SO ₃ H). At this time, the polymer as the starting material may be a polyether ether ketone, a polyarylene ether ketone, a polysulfone, a polyarylene ether sulfone, a polyimide, a polybenzimidazole, a polybenzoxazole, , Polypyrrolone, polyphosphazene, and copolymers thereof, and more preferably an aromatic polyether ether ketone is preferable. The sulfonating agent may be sulfuric acid (H ₂ SO ₄ ), sulfur trioxide (SO ₃ ), chlorosulfonic acid (ClSO ₃ H), or the like. In this case, 20 to 30 g of the polymer is charged into a reactor of 400 ml of the sulfonating agent, stirred at room temperature, and stirred for 100 to 150 hours in an inert atmosphere (nitrogen atmosphere or the like) to prevent oxidation, thereby preparing a sulfonated polymer . It should be washed with distilled water and dried.

(2) Sulphinase (-SO ₂ ) introduction step

In order to introduce a sulfinic group (-SO ₂ ) as a reactive group for crosslinking to the sulfonated polymer, the sulfonated polymer is dissolved in thionyl chloride (SOCl ₂ ) or the like. At this time, the sulfonated polymer is substituted with -SO ₂ Cl in place of the sulfone group (-SO ₃ H). Specifically, 10 to 15 g of a sulfonated polymer is added to 200 ml to 250 ml of thionyl chloride (SOCl ₂ ), N, N-dimethylformamide (DMF) is added thereto, Stir at ~ 80 ° C. The distillation is carried out at 85 to 90 ° C for 45 to 50 minutes to remove residual SOCl ₂ . Next, it is preferable that the distilled polymer is diluted in tetrahydrofuran (THF), and then the diluted solution is precipitated in alcohols (methanol, iso-propanol, etc.), washed and dried.

(3) Partial reduction step

The polymer into which the -SO ₂ Cl group is introduced is partially reduced so that a sulfinic group (-SO ₂ ) and a sulfonic acid group (-SO ₂ M; wherein M is a metal) are simultaneously present in the polymer. The sulfonic acid group (-SO ₂ M) is preferably a sulfonic acid lithium group (-SO ₂ Li) having good crosslinking reactivity. To this end, a sulfonic acid sodium group (-SO ₂ Na) It is preferable to replace the sodium sulfonate group (-SO ₂ Na) with a lithium sulfonate group (-SO ₂ Li).

Specifically, the -SO ₂ Cl group is sodium sulfite for, first, partial reduction to the sodium group (-SO ₂ Na) acid present in the introduced polymer (sodium sulfite, Na2SO3), sodium sulfide hydrate (sodium sulfide hydrate, Na ₂ S and nH ₂ O) is reacted into the -SO ₂ Cl groups introduced into the polymer solution prepared in part of the reducing agent (2) in such. Next, lithium chloride (LiCl), lithium acetate dihydrate (CH ₃ COOLi.H 2 O) to replace the sodium sulfonate group (-SO ₂ Na) with the lithium sulfonate group (-SO ₂ Li) ₂ O) or the like. It is better to wash with distilled water and dry.

(4) Casting solution preparation step

The partially reduced polymer in step (3), specifically, the polymer having -SO ₂ Cl group and -SO ₂ Li introduced into the polymer is mixed with an organic solvent, and then a crosslinking agent is added and stirred to prepare a casting solution do. At this time, the crosslinking agent may be added in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the partially reduced polymer in the step (3), though not particularly limited, but the alkene iodide is used. In addition, the inorganic acid, the metal carbonate and the inorganic acid are mixed together and the metal oxide is added. The amount of the inorganic acid is 1.0 ~ 60% by weight and the amount of the metal oxide is 0.5 ~ 10% by weight.

(5) Casting step

The above casting solution is coated in the same manner as usual, and then dried to prepare a film.

(6) Metal substitution step of H ⁺ of inorganic acid

In order to prevent leaching of inorganic acid contained in the dried membrane, the substitution process is carried out by adding H ⁺ of inorganic acid to 100-300 mL of a 1,2-group metal carbonate (MCO ₃ or M ' ₂ CO ₃ ) solution. At this time, the concentration of the metal carbonate solution is suitably about 0.1 to 2M. After replacement, wash with distilled water to remove any excess solution.

(7) Substitution of sulfone group (-SO ₃ H)

The membrane thus prepared has a -SO ₂ Cl group, which is substituted with a sulfone group (-SO ₃ H). Specifically, the above-mentioned (3) by partial reduction of the step, a portion of the -SO ₂ Cl group is substituted with -SO ₂ Li, some of which there remains a group -SO ₂ Cl, wherein (6) the film sulfuric acid prepared in Step (H ₂ SO ₄ ) solution or the like to replace the -SO ₂ Cl group with -SO ₃ H.

The polymer electrolyte membrane according to the present invention can be produced through the above process. The cross-linking of the unit block B in the above Chemical Formulas 1 to 3 can be performed not only by the addition amount of the cross-linking agent but also by the sulfonic acid Can be controlled depending on the degree of introduction of the base (-SO ₂ M). As described above, in the above formulas (1) to (3), the larger m and p are, the more favorable for ion exchangeability, and the greater the n and q, the better the mechanical properties. q) can be controlled according to the degree of introduction of the sulfonic acid group (-SO ₂ M) in the step (3). More specifically, the molar concentration or amount of the partial reducing agent such as sodium sulfite (Na ₂ SO ₃ ) and sodium sulfide hydrate (Na ₂ S · nH ₂ O) solution, and lithium chloride , The ratio of m (p) to n (q) can be controlled by controlling the concentration or the amount of the lithiating agent such as lithium acetate dihydrate (CH ₃ COOLi · 2H ₂ O) . For example, if the molar concentration (M) of the sodium sulfite (Na ₂ SO ₃ ) solution used as the partial reducing agent is small, the electrochemical characteristics such as ion conductivity may be high but the mechanical properties may be deteriorated. On the other hand, If the molar concentration (M) of the Fate (Na ₂ SO ₃ ) solution is high, the electrochemical characteristics such as ionic conductivity are low, but the mechanical properties can be improved. (Na ₂ SO ₃ ) solution used as a partial reducing agent is used in an amount of 0.5 to 2.0 molar (M), and a lithium chloride (LiCl) solution used as a lithiating agent is used in an amount of 5 to 10 wt% % Can be used.

The metal oxide on which the carbonate metal and the inorganic acid are carried together can be produced through the following process.

[Process for producing a metal oxide supported with a carbonate metal and an inorganic acid]

(1) Step of supporting a metal carbonate

A metal oxide containing two oxygen atoms is stirred in an aqueous solution of a carbonate metal reagent to carry a carbonate metal reagent to the pores of the metal oxide. Thereafter, a metal oxide bearing a carbonate metal is obtained through a drying and sintering process.

(2) Step of supporting inorganic acid

The above-prepared metal oxide supported on the metal oxide is stirred in a mineral acid aqueous solution to support the inorganic acid in the pores of the metal oxide through the substitution process of M ^{n +} (n = 1 or 2) of the metal carbonate and H ⁺ of the inorganic acid. At this time, the metal carbonate serves to more effectively support the inorganic acid in the pores of the metal oxide and at the same time prevents the inorganic acid carried on the metal oxide from leaching out of the aqueous solution. After stirring, drying and sintering are carried out to obtain a metal oxide on which a carbonate metal and an inorganic acid are supported together.

In addition, depending on the ratio of the metal oxide to be added, the decomposition of the electrolyte membrane due to the free radicals generated during the electrochemical reaction can be prevented. However, as the proportion of the added metal oxide increases, the performance as an electrolyte membrane is not expected as the hydrogen ion conductivity decreases . If the addition amount is small, the ability to protect against decomposition by free radicals is decreased, and it is difficult to guarantee the lifetime of the electrolyte membrane. Therefore, although not specifically defined, about 0.5-5.0% of the polymer mass may minimize the decrease of the hydrogen ion conductivity and maximize the lifetime of the electrolyte membrane. Examples of usable metal oxides include MnO ₂ , SiO ₂ and CeO ₂ , and carbonate metal reagents such as K ₂ CO ₃ , Cs ₂ CO ₃ and CaCO ₃ .

The polymer electrolyte membrane according to the present invention described above is included in the present invention as long as it is used for ion exchange in its application. It is preferably usable as an electrolysis of water (electrolytic solution) or an ion exchange membrane (electrolyte membrane) such as a fuel cell.

Meanwhile, the electrolytic solution and the fuel cell according to the present invention may have the same structure as that of the conventional electrolytic solution and the polymer electrolyte membrane according to the present invention may be used as the electrolyte.

The electrolytic solution according to the present invention includes at least a membrane-electrode assembly (MEA) having an electrolyte membrane, an anode formed on both surfaces of the electrolyte membrane, and a cathode catalyst layer, for example, And a frame arranged in a form capable of being discharged; A separator; A MEA support, a gasket (packing), and the like. At this time, the electrolyte membrane constituting the membrane-electrode assembly (MEA) is composed of the polymer electrolyte membrane according to the present invention.

Further, the fuel cell according to the present invention is, for example, a solid polymer fuel cell (PEFC) having the same structure as that of the conventional one, and includes an electrolyte membrane, a catalyst layer bonded to both sides of the electrolyte membrane, and a gas diffusion layer bonded to the outside of the catalyst layer Electrode assembly (MEA). A separator is disposed in the membrane-electrode assembly (MEA), and a gas flow path for supplying the fuel gas or the oxidizing agent gas may be formed in the contact portion of the membrane-electrode assembly (MEA) and the separator or in the separator. In addition, the fuel cell has a fuel electrode to which fuel gas such as hydrogen or methanol is supplied, and an oxygen electrode to which oxidant gas such as air or oxygen is supplied. At this time, the electrolyte membrane constituting the membrane-electrode assembly (MEA) is composed of the polymer electrolyte membrane according to the present invention.

Further, the fuel cell system according to the present invention may have the same structure as the conventional one, and any fuel cell using the fuel cell according to the present invention may be included in the present invention. For example, a fuel cell system according to the present invention includes a fuel cell; A hydrogen generation device for generating hydrogen from the raw material gas and supplying hydrogen to the fuel electrode of the fuel cell; An oxidant gas supply device for supplying oxidant gas (air, oxygen, etc.) to the oxygen electrode of the fuel cell; A fuel gas opening / closing means for opening / closing an entrance of the fuel electrode; Oxidant gas opening / closing means for opening / closing an entrance of the oxygen electrode; Hydrogen opening and closing means for opening and closing an entrance of the hydrogen generating apparatus; A control device for controlling the opening and closing operations of the fuel gas opening / closing means, the oxidizing gas opening / closing means, and the hydrogen opening / closing means. At this time, the fuel cell is composed of the fuel cell including the polymer electrolyte membrane according to the present invention. The water electrolysis apparatus according to the present invention may be applied to the hydrogen generating apparatus constituting the fuel cell system according to the present invention.

Hereinafter, embodiments of the present invention will be exemplified. The following examples are provided to explain the present invention in more detail, and thus the technical scope of the present invention is not limited thereto.

A cured crosslinked SPEEK membrane (SPEEK; meaning sulfonated PEEK) was prepared by using a polyether ether ketone (hereinafter referred to as 'PEEK') in the following manner.

1. Manufacture of SPEEK

First, 20 g of PEEK (Vitrex, 450G) was dried at 100 ° C. for 12 hours to remove water completely. Then, 400 ml of sulfuric acid (H ₂ SO ₄ ) was added to the three-necked flask and stirred at room temperature. At this time, nitrogen atmosphere was maintained to prevent oxidation, and the mixture was completely dissolved by stirring at a stirring speed of 350 rpm for 120 hours. The prepared polymer was precipitated in ice water and again precipitated in distilled water for 12 hours. The precipitated polymer was repeatedly washed with distilled water several times until the pH reached 7 ~ 8, and then completely dried for 24 hours in a vacuum dryer at 100 ° C to prepare SPEEK (sulfonated polyether ether ketone) having a sulfonation degree of 90% or more Respectively.

2. Preparation of PEEK-SO ₂ Cl

12 g of the prepared SPEEK was dissolved in 200 ml of thionyl chloride (SOCl ₂ ) and then 3 ml of N, N-dimethylformamide (DMF) was added to the prepared SPEEK in order to introduce the sulfine group. And the mixture was stirred at 60 ° C for 3 hours. Distillation was carried out at 85 ° C for 50 minutes to remove residual SOCl ₂ . The distilled polymer was diluted with 20 ml of tetrahydrofuran (THF), the diluted solution was precipitated in methanol, and the resulting polymer was washed several times. The resulting polymer was again dissolved in 120 ml of THF, precipitated in methanol, washed several times, and completely dried in a vacuum drier at 25 ° C for 24 hours to prepare PEEK-SO ₂ Cl.

3. Preparation of PEEK-SO ₂ Cl-SO ₂ Li

8 g of the prepared PEEK-SO ₂ Cl and 2 molar concentration of sodium sulfate (Na ₂ SO ₃ ) were added to a three-necked flask and stirred at 70 ° C. for 24 hours to obtain a partial To thereby introduce -SO ₂ Na group into the polymer. (Preparation of PEEK-SO ₂ Cl-SO ₂ Na)

Next, remove the white suspension been generated, and this was replaced with stirring lithium chloride (lithium chloride, LiCl) of 7wt% solution during 1 hour a group -SO ₂ Li, instead of group -SO ₂ Na. After repeatedly washing with distilled water several times, the partially reduced PEEK-SO2Cl-SO2Li was prepared by completely drying in a vacuum dryer at 40 ° C for 24 hours.

4. Manufacture of Membrane

3 g of the prepared polymer (PEEK-SO2Cl-SO2Li) was added to a solvent of n-methyl-2-pyrrolidinone (NMP) to dissolve the polymer, and then phosphomolybdic acid was added to the polymer in an amount of 40 wt% Lt; / RTI > 0.05 ml of 1,4-diiodobutene was added as a crosslinking agent, and then stirred vigorously for 40 minutes to prepare a casting solution. The casting solution was cast in a coating machine (Sinil Eng., Korea) and then dried at room temperature for 12 hours, then dried at 60 ° C for 4 hours, and then dried at 120 ° C for 12 hours To prepare a membrane. Next, by immersing the inorganic acid by replacing the H ⁺ Cs ⁺ in a 0.1 molar concentration (M, mole / ℓ) 24 hours a solution of Cs ₂ CO ₃ in order to prevent leaching of the mineral acid. The substituted membrane was immersed in a 10 wt% H ₂ SO ₄ aqueous solution for 24 hours to replace the sulfine group with a sulfone group to prepare a solid polymer electrolyte membrane (covalently crosslinked SPEEK / Cs-MoPA membrane) according to this example.

(Cs _x H _{3 - x} O ₄₀ PMo ₁₂ ) as a metal oxide on which the carbonate metal and the inorganic acid were supported together before the addition of the cross-linking agent was carried out in the same manner as in Example 1, except that the phosphomolybdic acid The supported ceria (CeO ₂ ) was further added to prepare a film. In order to investigate the characteristics of the membrane depending on the amount of the metal oxide supported on the metal carbonate and the inorganic acid, ceria (CeO ₂ CO ₃ ) and phosphomolybdic acid (H ₃ O ₄₀ PMo ₁₂ ) ₂ ) was added to the casting solution in different amounts of 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt% and 4.0 wt%.

[Process for producing a metal oxide supported with a carbonate metal and an inorganic acid]

1. Preparation of Metal Oxide Carrying Metal Carbonate

Add 0.2 g of CeO ₂ into a 50 ml beaker and slowly add an aqueous solution of Cs ₂ CO _{3 at a} concentration of 0.008 mol (M, mole / ℓ) and stir at high speed for 1 hour. After the stirring, the powder was dried at 100 DEG C for 24 hours, and the obtained powder was sintered at 300 DEG C for 3 hours to prepare a metal oxide bearing a carbonate.

2. Preparation of metal oxide bearing inorganic acid

0.2 g of the above-prepared Cs ⁺ supported CeO ₂ was slowly added dropwise to an aqueous solution of 0.008 mol (M, mole / l) of phosphomolybdic acid, followed by stirring at a high speed for 1 hour. After the stirring, the resulting powder was dried at 100 ° C. for 24 hours, and the obtained powder was sintered at 300 ° C. for 3 hours to obtain ceria (Cs ₂ CO ₃ ) and ceria (H ₃ PMo ₁₂ O ₄₀ ) CeO ₂ ).

[Comparative Example 1]

(CeO ₂ , hereinafter referred to as ceria (CeO ₂ )) in which cesium carbonate (Cs ₂ CO ₃ ) and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) 1 was used as a sample of the comparative example.

(S / cm), ion exchange capacity (meq / g-dry-membr.), Water content (%) and tensile strength (%) of the membrane specimens according to the above- MPa), elongation (%) and oxidation durability were evaluated.

<Characteristic Evaluation of Electrolyte Membrane>

1. Functional analysis

In order to confirm the presence of functional groups introduced in each step of Example 1, an infrared spectroscopic analyzer (FT-IR, MB104 manufactured by BOMEM) was used. The results of the analysis according to the FT-IR are shown in FIGS. 1 and 2.

The first step of sulfonation is 1080 cm ^- was confirmed that the sulfone group is introduced into the PEEK polymer through the symmetric stretching vibration in the vicinity of ^1. The second step, sulphide substitution, was confirmed by the asymmetric stretching vibration peak change at 1385 ~ 1360 cm ^-1 . Lithiated then reduced portion of the third stage was confirmed by the stretching vibration of S = O at 980 cm ^-1, as in the fourth step the disappearance of the 980 cm ^-1 peak of 1,4-DI Goto portion heptane (1 , 4-Diiodobutane).

Comparative Example 1 Mo = O _t (molybdenumterminaloxygen) at 956 and _{^{927 cm -1, Mo-O c}} -Mo (molybdenum-corner-sharedoxygen) are 866, 858 and _{^{842 cm -1, Mo-O e}} -Mo ( molybdenum-edge-sharedoctahedra) confirmed the introduction of phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) and ceria (CeO ₂ ) through stretching vibration at 795, 782 and 765 cm ^-1 , respectively.

2. Evaluation of thermal stability

TGA experiments were performed using a thermal mass spectrometer (TS 2950, TA Instruments) to confirm the thermal stability of the prepared films. The results are shown in the attached FIG. 3. In Figure 3, CL-SPEEK / Cs- MoPA / CeO 2 x% electrolyte membrane is carried out with cesium carbonate in Example ₂ (Cs 2 CO ₃₎ and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀₎ The ceria (CeO supported with ₂ ) was added to the polymer mass, and the CL-SPEEK / Cs-MoPA electrolyte membrane was an electrolyte membrane of Comparative Example 1 in which ceria (CeO ₂ ) was not added.

As shown in Fig. 3, all membranes showed three levels of mass reduction. The first mass loss occurred at 50 ~ 200 ℃ due to mass loss due to evaporation of bound water. The second mass reduction occurred at 450 ~ 490 ℃ due to mass loss due to decomposition of sulfonic acid group. The third mass reduction occurred at around 550 ℃ due to mass loss due to the decomposition of the polymer main chain. This decomposition temperature is a polymer electrolyte membrane used for electrolytic dissolution and the like, and has stable thermal properties.

3. Evaluation of hydrogen ion conductivity by temperature

The membrane according to Example 2 and Comparative Example 1 was evaluated for hydrogen ion conductivity by temperature using an impedance meter (solartron 1260 analyzer). At this time, the hydrogen ion conductivity (S / cm) was calculated by substituting the following equation (1) after measuring the resistance (?) At 1 KHz. The results are shown in Table 1 below. In Table 1, Example 2 is an electrolyte membrane added with ceria (CeO ₂ ) in which cesium carbonate (Cs ₂ CO ₃ ) and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) -SPEEK / Cs-MoPA electrolyte membrane is an electrolyte membrane in which ceria (CeO ₂ ) is not added as Comparative Example 1

[Equation 1]

_{σ = l / ((r 2} -r 1) × S)

In the above equation,

? is hydrogen ion conductivity (S / cm),?

r ₁ is the electrical resistance (Ω) of pure 1 MH ₂ SO ₄ aqueous solution when there is no membrane,

r ₂ is an electric resistance (Ω) measured by inserting a film,

S is the area of the film (cm 2), and 1 is the thickness (cm) of the film.

&Lt; Evaluation results of hydrogen ion conductivity according to temperature > division Electrolyte membrane Temperature (℃) 25 ℃ 80 ℃ Example 2 CeO ₂ 0.5% 1.1 × 10 ^-1 -1.2 × 10 ^-2 1.7 x 10 ^-1 to 1.8 x 10 ^-1 CeO ₂ 1% 9.0 x 10 ^-2 to 1.0 x 10 ^-1 1.5 x 10 ^-1 to 1.6 x 10 ^-1 CeO ₂ 2% 9.0 x 10 ^-2 to 1.0 x 10 ^-1 1.4 x 10 ^-1 -1.5 x 10 ^-1 CeO ₂ 3% 9.0 x 10 ^-2 to 1.0 x 10 ^-1 1.2 x 10 ^-1 to 1.3 x 10 ^-1 CeO ₂ 4% 6.0 x 10 ^-2 to 7.0 x 10 ^-2 9.0 × 10 ^-2 to 1.0 × 10 ^-2 Comparative Example 1 No CeO ₂ 6.0 x 10 ^-2 to 7.0 x 10 ^-2 1.7 x 10 ^-1 to 1.8 x 10 ^-1

As shown in Table 1, the hydrogen ion conductivity tended to decrease gradually as the amount of ceria (CeO ₂ ) was increased. This is due to the addition of metal oxides with low hydrogen ion conductivity. However, it showed high hydrogen ion conductivity by phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) added as inorganic acid.

4. Evaluation of ion exchange capacity

The ion exchange capacity of the membrane according to Example 2 and Comparative Example 1 was measured by an acid-base titration method. The results are shown in Table 2 below.

&Lt; Evaluation results of ion exchange capacity > division Electrolyte membrane Ion exchange capacity (meq / g-dry-membr.) Example 2 CeO ₂ 0.5% 2.11 CeO ₂ 1% 3.56 CeO ₂ 2% 2.45 CeO ₂ 3% 1.68 CeO ₂ 4% 1.08 Comparative Example 1 No CeO ₂ 2.56

As shown in Table 2, Example 2 is ceria (CeO ₂₎ the cesium is substituted phosphomolybdic acid in accordance with the addition of the supported on ceria (CeO ₂₎ to prepare 1% polymer (Cs _x H _{3 - x} PMo ₁₂ O ₄₀ ) increased the ion exchange capacity, but the ion exchange capacity gradually decreased due to the increased interaction with the polymer sulfonic acid group at the higher ratio.

According to Tables 1 and ₂ , the hydrogen ion conductivity and ion exchange capacity can be controlled by adjusting the content of ceria (CeO ₂ ).

5. Moisture content evaluation

The water content of the electrolyte membrane according to Example 2 and Comparative Example 1 was measured, and the results are shown in Table 3 below. In Table 3, Example 2 is an electrolyte membrane to which ceria (CeO ₂ ) carrying cesium carbonate (Cs ₂ CO ₃ ) and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) -SPEEK / Cs-MoPA electrolyte membrane is an electrolyte membrane of Comparative Example 1 in which ceria (CeO ₂ ) is not added. In this case, the water content (%) was evaluated by calculating the following formula (2) after swelling the produced electrolyte membrane in distilled water for one day.

&Quot; (2) &quot;

Moisture content (%) = [(film weight after swelling-film weight before swelling) / film weight before swelling] x 100

<Results of water content evaluation> division Electrolyte membrane Moisture content (%) Example 2 CeO ₂ 0.5% 48.3 CeO ₂ 1% 55.3 CeO ₂ 2% 58.4 CeO ₂ 3% 52.2 CeO ₂ 4% 34.5 Comparative Example 1 No CeO ₂ 44.7

As shown in Table 3, as the ceria (CeO ₂ ) was added, the water content increased from 2% to the maximum due to the hydrophilic nature. When the amount of the ceria increased, the interaction with water And the water content gradually decreased.

6. Evaluation of mechanical properties

The mechanical properties (tensile strength and elongation) of the films according to Example 2 and Comparative Example 1 were measured, and the results are shown in Table 4 below. The measuring instrument was LR-5K manufactured by Llyod Co., Ltd. and the tensile strength and elongation of the membrane were measured at 25 ° C at room temperature according to ASTM D 882. Example 2 is an electrolyte membrane prepared by adding ceria (CeO ₂ ) carrying cesium carbonate (Cs ₂ CO ₃ ) and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀ ) together to a polymer mass, and CL-SPEEK / Cs- The MoPA electrolyte membrane is an electrolyte membrane in which ceria (CeO ₂ ) is not added as Comparative Example 1.

<Results of Mechanical Properties Evaluation> division Electrolyte membrane Tensile Strength (MPa) Elongation (%) Example 2 CeO ₂ 0.5% 43.6 89.8 CeO ₂ 1% 40.1 171.3 CeO ₂ 2% 45.4 130.4 CeO ₂ 3% 40.3 79.8 CeO ₂ 4% 51.3 23.1 Comparative Example 1 No CeO ₂ 65.7 69.1

As shown in Table 4, with the addition of ceria (CeO ₂ ), tensile strength decreased and elongation increased. It was confirmed that the elongation ratio increased with increasing moisture content of ceria (CeO ₂ ) depending on the hydrophilicity of the ceria (CeO ₂ ) and tensile strength decreased due to interaction with polymer chains due to interaction with moisture.

7. Evaluation of oxidation durability characteristics

The oxidation durability of the electrolyte membrane according to Example 2 and Comparative Example 1 against free radicals was measured and is shown in Table 5. The measurement of oxidation durability was performed by measuring the final decomposition time of the membrane in a Fenton solution prepared by mixing 3 ppm of iron sulfate (FeSO ₄ ) and 5 wt% of hydrogen peroxide (H ₂ O ₂ ). The reaction scheme for generating free radicals in the Fenton solution is shown in Scheme 1 below.

[Reaction Scheme 1]

H ₂ O ₂ + Fe ^{2 +} → OH + OH ^- + Fe ^{3 +}

Fe ^{3 +} + H ₂ O _{2 -} & gt ^; Fe ^{2 +} + - OOH + H ⁺

<Oxidation durability evaluation result> division Electrolyte membrane Final decomposition time (h: min) Example 2 CeO ₂ 0.5% 491: 00 CeO ₂ 1% 714: 00 CeO ₂ 2% 802: 00 CeO ₂ 3% 861: 00 CeO ₂ 4% 1059: 00 Comparative Example 1 No CeO ₂ 574: 22

It was confirmed that the final decomposition time of the film increased with the addition of ceria (CeO ₂ ). This is because the chemical durability of the polymer electrolyte membrane is improved due to the function of free radical scavenger by ceria (CeO ₂ ).

&Lt; Preparation of membrane-electrode assembly (MEA)

A platinum catalyst was impregnated using a impregnation-reduction method suitable for electrolytic electrolysis as a method for producing a membrane-electrode assembly (MEA), and an electrolytic solution in which the addition amount of ceria (CeO ₂ ) in Example 2 was 1% And a Pt / PEM MEA was prepared by a conventional method using Nafion 117 (manufactured by DuPont), which is a commercially available membrane. The prepared MEA was applied to the electrolytic cell to measure the voltage and the current density during the electrolysis of water. The platinum reagent used was tetraammineplathnium (II) chloride hydrate (Pt (NH ₃ ) ₄ Cl ₂ ) as a platinum cationic compound and sodium borohydride (NaBH ₄ ) as a reducing agent. Were used. Pt (NH ₃₎ of 5 mmol / L to stop removal of the impurities through the pre-treatment ₄ Cl ₂₎ After soaking for 1 hour in an aqueous solution, to remove the platinum reagents, and using a reducing agent NaBH ₄ adjusted to pH 13 0.8 mol / L &Lt; / RTI &gt; for 90 minutes.

FIG. 6 is a graph showing a CV curve of the MEA fabricated as described above, and FIG. 7 is a graph of current-voltage applied to the power-receiving cell.

As shown in FIG. 6, according to the present invention, the MEA prepared with 1% of the covalently crosslinked SPEEK / Cs-MoPA / CeO ₂ (Example 2) exhibited a high charge amount of 44.65 mC / cm ² . This high charge means that more reaction took place over the same time period, which means an electrode with a faster reaction rate.

The total number of moles of charges flowing during the hydrogen adsorption / desorption process was calculated as the electrochemically active surface area ECA (m 2 -Pt / g-Pt) using the proportional constant 210 μC / cm 2, which is the amount of current required for the adsorption of hydrogen monomolecular layer on the Pt surface. Can be calculated. As a result of evaluating the active surface area of the MEA thus prepared, the active surface area of the MEA to which 1% of the covalently crosslinked SPEEK / Cs-MoPA / CeO ₂ (Example 2) was applied was evaluated to be 12.559 m 2 / g, The active surface area of the applied MEA was estimated to be 10.731 ㎡ / g, showing better characteristics.

As shown in FIG. 7, the electrolysis voltage of water at 1 A / cm 2 was 1.94 V in the case of the cell to which the Nafion 117 membrane was applied, 1% of the covalently crosslinked SPEEK / Cs-MoPA / CeO ₂ (Example 2) Cs-MoPA / CeO ₂ 1% (Example 2) film was applied at 1.85 V in the case of the applied cell.

From the above results, in such amount of current of the electrode (MEA), the active surface area, the platinum loading, and the electrical performance of the power reception by the cell, according to the present invention, cesium carbonate (Cs2CO3) and phosphomolybdic acid (H ₃ PMo ₁₂ O ₄₀₎ is (Cs _x H _3-x PMo ₁₂ O ₄₀ ) added to cerium (Cs ⁺ ) and cerium (Cs ⁺ ) -substituted membranes to which cerium (CeO ₂ ) It was found that the Nafion product had better characteristics than the commercialized Nafion product.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Therefore, it is to be understood that the present invention is not limited to the above-described embodiments. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims. It is also to be understood that the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims (21)

A polymer electrolyte membrane comprising a polymer having a repeating unit represented by the following formula, further comprising an inorganic acid and a metal oxide.
[Chemical Formula]

(Wherein R is hydrocarbon and m, n, p and q are an integer of 1 or more).
The method according to claim 1,
Wherein m = p in the formula and n = q.
The method according to claim 1,
And 1.0 to 60% by weight of the inorganic acid.
The method according to claim 1,
Wherein the inorganic acid is one or a mixture of two or more selected from the group consisting of phosphotungstic acid, zirconium phosphate, silicotungstic acid, phosphomolybdic acid, and silicomolybdic acid.
The method according to claim 1,
Wherein the metal oxide comprises a metal carbonate and an inorganic acid.
6. The method of claim 5,
Wherein the inorganic acid is one or a mixture of two or more selected from the group consisting of phosphotungstic acid, zirconium phosphate, silicotungstic acid, phosphomolybdic acid, and silicomolybdic acid.
6. The method of claim 5,
Wherein the metal of the metal carbonate is a metal carbonate containing a metal of Group 1 or Group 2 in the periodic table.
The method according to claim 1,
And 0.5 to 10% by weight of the metal oxide.
A first step of introducing a sulfone group (-SO ₃ H) into the polymer;
A second step of introducing a sulfinic group (-SO ₂ ) into the sulfonated polymer;
A third step of partially reducing the sulfurized polymer so that a sulfinic group (-SO ₂ ) and a sulfonic acid group (-SO ₂ M; M is a metal) are present in the polymer;
A fourth step of mixing the partially reduced polymer with a solvent, and then adding and stirring the cross-linking agent to prepare a casting solution;
A fifth step of coating the casting solution to produce a film; And
And a seventh step of replacing the sulfinic group (-SO ₂ ) of the prepared membrane with a sulfone group (-SO ₃ H)
Further comprising the step of adding an inorganic acid and a metal oxide before adding the crosslinking agent in the fourth step.
10. The method of claim 9,
And a sixth step of replacing H ⁺ of the inorganic acid with a metal.
10. The method of claim 9,
In the third step,
Step a) to partial reduction so that the sulfonic acid sodium in the polymer pinhwa group (-SO ₂ Na) exists; And a step (b) of replacing the sodium sulfonate group (-SO ₂ Na) with a lithium sulfonate group (-SO ₂ Li).
10. The method of claim 9,
Wherein the inorganic acid is one or a mixture of two or more selected from the group consisting of phosphotungstic acid, zirconium phosphate, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid, and the metal oxide includes two oxygen Wherein the polymer electrolyte membrane is a polymer electrolyte membrane.
10. The method of claim 9,
The polymer may be selected from the group consisting of polyetheretherketone, polyarylene ether ketone, polysulfone, polyarylene ether sulfone, polyimide, polybenzimidazole, polybenzoxazole, polybenzothiazole, polypyrrolone, polyphosphazene, Wherein the polymer electrolyte membrane is one or two or more selected from the group consisting of a copolymer and a copolymer.
10. The method of claim 9,
Wherein the cross-linking agent in the fourth step is an iodinated alkane.
12. The method of claim 11,
The step a)
Wherein a sodium sulfite (Na ₂ SO ₃ ) solution having a concentration of 0.5 to 2.0 mol (M) as a partial reducing agent is used.
A water electrolytic solution comprising a polymer electrolyte membrane according to any one of claims 1 to 8.
A water electrolysis apparatus comprising a polymer electrolyte membrane produced by the process for producing a polymer electrolyte membrane according to any one of claims 9 to 15.
A fuel cell comprising the polymer electrolyte membrane according to any one of claims 1 to 8.
A fuel cell comprising a polymer electrolyte membrane produced by the process for producing a polymer electrolyte membrane according to any one of claims 9 to 15.
A fuel cell system comprising a fuel cell according to claim 18.
A fuel cell system comprising a fuel cell according to claim 19.

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