JP2007257896A - High protonic conductive electrolyte film and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high protonic conductive electrolyte film having a relatively high protonic conductivity and its manufacturing method. <P>SOLUTION: This invention includes the manufacturing method of the high protonic conductive electrolyte film including a complex forming process for forming anion-cation complex by dissolving solid polymer electrolyte and cation molecules in a solvent, a film forming process for casting film by using the solution obtained by the complex forming process and a removing process for removing equal to or more than 80% of the cation molecules from the film and the high protonic conductive electrolyte film obtained by the method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a high proton conductive electrolyte membrane and a method for producing the same, and more specifically, a polymer electrolyte fuel cell, a water electrolysis device, a hydrohalic acid electrolysis device, a salt electrolysis device, an oxygen and / or hydrogen concentrator, The present invention relates to a high proton conductive electrolyte membrane suitable as an electrolyte membrane used in various electrochemical devices such as a humidity sensor and a gas sensor, and a method for producing the same.

  A solid polymer fuel cell has a membrane electrode assembly (MEA) in which electrodes are bonded to both surfaces of a solid polymer electrolyte membrane as a basic unit. In the polymer electrolyte fuel cell, the electrode generally has a two-layer structure of a diffusion layer and a catalyst layer. The diffusion layer is for supplying reaction gas and electrons to the catalyst layer, and carbon paper, carbon cloth, or the like is used. The catalyst layer is a part that becomes a reaction field for electrode reaction, and generally comprises a composite of carbon carrying an electrode catalyst such as platinum and a solid polymer electrolyte (electrolyte in the catalyst layer).

  For the electrolyte membrane or the catalyst layer electrolyte that constitutes such an MEA, a fluorine-containing electrolyte having excellent oxidation resistance (for example, Nafion (registered trademark, manufactured by DuPont)), Aciplex (registered trademark, Asahi Kasei Co., Ltd.) And Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.)) are generally used. In addition, the fluorine-containing electrolyte is excellent in oxidation resistance, but is generally very expensive. Therefore, in order to reduce the cost of the polymer electrolyte fuel cell, the use of a hydrocarbon-based electrolyte has been studied.

The first characteristic required for these solid polymer electrolyte membranes is to have high proton conductivity. This is because by using a membrane having high proton conductivity, a voltage drop is reduced at a high current density in fuel cell operation, and a high battery output can be extracted.
For the production of a solid polymer electrolyte membrane, a casting method is generally used in which a solution of a solid polymer electrolyte and an organic solvent is cast on a substrate and the solvent is removed at a high temperature to obtain a membrane. . As a method for improving the proton conductivity of the solid polymer electrolyte membrane obtained by such a casting method,
(1) Method of heating a membrane in water or under saturated water vapor pressure (Patent Document 1)
(2) Method for removing solvent under humidified atmosphere (Patent Document 2)
(3) Method using two kinds of solvents having different boiling points as a solvent (Patent Document 3)
Etc. are known.

JP-A-9-199144 JP 2003-249245 A JP 2003-249244 A

It is said that proton conductivity is improved when the above-described treatment is performed on a membrane obtained by the casting method. This is considered to be because the proton acid groups in the membrane are rearranged by performing the above-described treatment, and a relatively large proton conduction path is formed. However, the method of heating the film under specific conditions or performing the solvent removal under specific conditions is a roundabout method. Further, the method using two kinds of solvents has a drawback that it can be applied only to an electrolyte that dissolves in a low boiling point solvent.
Furthermore, the electrolyte membrane generally swells when it contains water. For this reason, even if a relatively large proton conduction path is formed by the above-described treatment, the structure formed inside the membrane is broken by repeated swelling and shrinkage during use, and proton conductivity may be lowered.

The problem to be solved by the present invention is to provide a high proton conductive electrolyte membrane having a relatively high proton conductivity and a method for producing the same.
Another object of the present invention is to provide a high proton conductive electrolyte membrane capable of maintaining a relatively high proton conductivity even after repeated swelling and shrinkage, and a method for producing the same. is there.
Furthermore, another problem to be solved by the present invention is to provide a method for producing a high proton conductive electrolyte membrane capable of producing an electrolyte membrane having such excellent characteristics by a simple method. .

In order to solve the above problems, a method for producing a highly proton conductive electrolyte membrane according to the present invention includes a complex formation step in which a solid polymer electrolyte and a cation molecule are dissolved in a solvent to form an anion / cation complex, and the complex formation The film obtained by casting is formed into a film to obtain a film, and the removal process of removing 80% or more of the cationic molecules from the film. In this case, before the film forming step, a cross-linking agent addition step of adding a first cross-linking agent having two or more cation moieties to the solution obtained in the complex forming step may be further provided. Further, after the removing step, a cross-linking introduction step of impregnating the film with a second cross-linking agent and introducing a cross-linked structure into the film may be further provided.
In addition, the high proton conductive electrolyte membrane according to the present invention is obtained by the method according to the present invention.

When the solid polymer electrolyte and the cation molecule are dissolved in a solvent, the proton of the proton acid group and the cation molecule are ion-exchanged to form an anion / cation complex. Subsequently, when the solution containing the solid polymer electrolyte into which the anion / cation complex is introduced is cast into a film, the anion / cation complex associates in the film. Further, when 80% of the cation molecules are removed from the obtained electrolyte membrane, relatively large continuous pores (proton conduction paths) corresponding to the size of the cation molecule are formed inside the electrolyte membrane. Therefore, proton conductivity is improved as compared with the case where the electrolyte is simply cast into a film.
In addition, when a crosslinked structure is introduced into the membrane, the formed proton conduction path is more firmly fixed. Therefore, even if the membrane repeatedly swells and contracts, a relatively high proton conductivity can be maintained.

Hereinafter, an embodiment of the present invention will be described in detail.
First, the high proton conductive electrolyte membrane and the manufacturing method thereof according to the first embodiment of the present invention will be described. The method for producing a high proton conductive electrolyte membrane according to the present embodiment includes a complex formation step, a membrane formation step, and a removal step. In addition, the high proton conductive electrolyte membrane according to the present embodiment is obtained by the method according to the present embodiment.

The complex formation step is a step of dissolving the solid polymer electrolyte and the cation molecule in a solvent to form an anion / cation complex.
In the present invention, the solid polymer electrolyte is not particularly limited, and may be either a fluorocarbon electrolyte or a hydrocarbon electrolyte.
Here, the “fluorocarbon electrolyte” refers to a perfluorinated electrolyte or a partially fluorinated electrolyte.
“Fully fluorinated electrolyte” means a polymer skeleton containing a C—F bond and no C—H bond. In the present invention, the term “perfluorinated electrolyte” refers to a structure other than the C—F bond (for example, —O—, —S—, —C (═O) —, —N (R) in the polymer skeleton. -Etc., provided that "R" is an alkyl group.)
The “partial fluorine-based electrolyte” refers to a polymer skeleton containing both C—F bonds and C—H bonds.
“Hydrocarbon-based electrolyte” means a polymer skeleton containing a C—H bond and no C—F bond.
The electrolyte membrane according to the present invention may contain only one of these electrolytes, or may contain two or more.

Among these, the solid polymer electrolyte is preferably composed of a polymer having at least one of an aromatic ring and a heterocyclic ring, and a protonic acid group bonded to at least one of the aromatic ring and the heterocyclic ring.
As such a solid polymer electrolyte,
(1) Polyarylene polymer (for example, polyether, polyketone, polysulfone, polyethersulfone, polyetherethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyphenylenesulfoxide, polyetherketoneketone, A polyamide system, a polyimide system, a polyamideimide system), and a protonic acid group bonded to any one or more of an aromatic ring and a heterocyclic ring included in the polymer,
(2) Including a polyazole-based polymer (for example, polybenzimidazole-based, polybenzothiazole-based, polybenzoxazole-based), and a protonic acid group is bonded to at least one of an aromatic ring and a heterocyclic ring included in the polymer. What
Is mentioned.
Examples of the proton acid group include sulfonic acid, phosphonic acid, and carboxylic acid, and among these, sulfonic acid is most preferable.

  Specifically, the solid polymer electrolyte containing a polymer (polyarylene polymer) containing a repeating structural unit having a polyarylene structure is preferably represented by the formula (1).

In the formula (1), X ₁ , X ₂ , and X ₃ are each composed of a single bond, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthyl group, and the like. Of these groups, a phenyl group and a naphthyl group are preferable. In addition, a protonic acid group is bonded to one or more of X ₁ , X ₂ , and X ₃ included in 20 to 100% of the entire polymer unit.
A, B and C each represent a divalent single bond or an organic group. Specifically, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) —, —C (CF ₂ ) ₂ —, — (CH ₂ ) —, — C (CH ₂ ) ₂ —, —O—, —S—, —CH═CH—, —C≡C— and the like can be mentioned.
n shows the integer of 10-10000.

  Specifically, the solid polymer electrolyte containing a polymer (polyazole polymer) containing a repeating structural unit having a polyazole structure is preferably represented by the formula (2).

In formula (2), X ₄ represents any of O, S, and N atoms. X ₅ represents a single bond, a phenyl group, a naphthyl group, an anthracenyl group, or a phenanthyl group. Further, the aromatic ring and / or heterocyclic ring X ₅ or in benzazole group contained 20 to 100% of the units of the total polymer units, protonic acid group is bonded.

  “Cation molecule” refers to a compound capable of forming an anion / cation complex by ion exchange with protons of protonic acid groups contained in a solid polymer electrolyte. Specific examples of such cationic molecules include amine compounds, ammonium salts, imidazole derivatives, pyridine derivatives, quinoline derivatives, pyridazine derivatives, pyrimidine derivatives, and pyrazine derivatives. These may be used alone or in combination of two or more.

Specific examples of the amine compound include butylamine, hexylamine, methylamine, ethylamine, propylamine, pentylamine, dimethylamine, trimethylamine, diethylamine, triethylamine, and phenylamine.
Specific examples of ammonium salts include tetrabutylammonium bromide, tetramethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrapentylammonium bromide, tetraheptylammonium bromide, tetrahexylammonium bromide, tetra Examples include octyl ammonium bromide, triethylhexyl ammonium bromide, and triethylmethyl ammonium bromide.
Specific examples of the imidazole derivative include imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 2-ethylimidazole, and 1,2-dimethylimidazole.
Specific examples of pyridine derivatives include pyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, and 1,2-dimethylpyridine iodide.
Specific examples of quinoline derivatives include quinoline, 3-methylquinoline, 6-methylquinoline, 7-methylquinoline, and 8-methylquinoline.
Specific examples of pyridazine derivatives include pyridazine and 4-methylpyridazine.
Specific examples of the pyrimidine derivative include pyrimidine, 4-methylpyrimidine, and 4,6-dimethylpyrimidine.
Specific examples of the pyrazine derivative include pyrazine, 2-methylpyrazine, ethylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine.

  Any solvent may be used as long as it can dissolve both the solid polymer electrolyte and the cation molecule. Specific examples of the solvent include dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), ethanol, methanol, propanol, 1,2-dichloroethane, carbon tetrachloride. , Chloroform, dichloromethane, O-dichlorobenzene, tetrahydrofuran (THF), methyl ethyl ketone, hexane, xylene, toluene and the like. These may be used alone or in combination of two or more. Further, the dissolution procedure in the solvent is not particularly limited, and any of them may be dissolved first as long as an anion / cation complex can be formed.

The amount of the solid polymer electrolyte dissolved in the solvent is not particularly limited, and can be arbitrarily selected in consideration of the solubility, workability, etc. of the solid polymer electrolyte.
The amount of the cation molecule may be any amount that can convert all of the protonic acid groups in the solid polymer electrolyte into an anion / cation complex. In general, the smaller the amount of cationic molecules, the more protonic acid groups remain, making it difficult to obtain a relatively large anion / cation complex association. Specifically, the amount of the cation molecule is preferably 50% or more, more preferably 80% or more of the amount capable of converting all the protonic acid groups into an anion / cation complex.
On the other hand, adding more cationic molecules than necessary has no real benefit. Accordingly, the amount of the cation molecule is preferably 150% or less, more preferably 120% or less of the amount capable of converting all proton acid groups into an anion / cation complex.

  The film forming step is a step of casting the solution obtained in the complex forming step to obtain a film. The film forming method is not particularly limited, and a known method can be used. When the solution is cast on the surface of an appropriate substrate (for example, polytetrafluoroethylene substrate, glass petri dish, etc.) and the solvent is removed, an electrolyte membrane containing an anion / cation complex is obtained.

The removing step is a step of removing 80% or more of the cation molecules from the membrane. The removal of the cation molecule is performed by immersing the obtained membrane in an acid aqueous solution. Specific examples of the acid used for removing the cation molecule include hydrochloric acid, nitric acid, sulfuric acid and the like. The acid concentration in the acid aqueous solution, the immersion time, and the like are not particularly limited as long as the cationic molecule can be efficiently removed.
Moreover, when the molecular weight of the cation molecule is large, it is preferable to perform a treatment for swelling the membrane before or simultaneously with the treatment with the acid aqueous solution. When the acid treatment is performed with the membrane slightly swollen, the cationic molecules can be easily removed. As such processing,
(1) A method of performing treatment with an aqueous acid solution at a relatively high temperature (room temperature to 100 ° C.),
(2) A method of adding an alcohol (for example, ethanol) to the acid aqueous solution,
and so on.

  Next, a high proton conductive electrolyte membrane and a method for manufacturing the same according to the second embodiment of the present invention will be described. The method for producing a high proton conductive electrolyte membrane according to the present embodiment includes a complex formation step, a crosslinking agent addition step, a membrane formation step, and a removal step. In addition, the high proton conductive electrolyte membrane according to the present embodiment is obtained by the method according to the present embodiment.

  The complex forming step is a step of dissolving the solid polymer electrolyte and the cation molecule in a solvent to form an anion / cation complex. The details of the complex formation process are the same as those in the first embodiment, and thus the description thereof is omitted.

The crosslinking agent adding step is a step of adding the first crosslinking agent to the solution obtained in the complex forming step.
Here, the “first crosslinking agent” refers to a compound having two or more cation moieties. Specific examples of the first crosslinking agent include those represented by the following formula (3). These may be used alone or in combination of two or more. In addition, Formula (3) shows that each repeating unit is connected with random or a block.

  The addition amount of a crosslinking agent is not specifically limited, It can select arbitrarily according to the objective. Generally, as the amount of the crosslinking agent added increases, the structure formed inside the film can be more firmly fixed. On the other hand, if the addition amount of the crosslinking agent is too large, protonic acid groups are consumed for crosslinking, so that proton conductivity decreases. Therefore, it is preferable to select the optimum addition amount of the crosslinking agent in accordance with the type of solid polymer electrolyte, required characteristics, and the like.

  The film forming step is a step of casting the solution obtained in the crosslinking agent adding step to obtain a film. Since the film forming process is the same as that of the first embodiment except that a solution containing the first cross-linking agent is used, the description thereof is omitted.

The removing step is a step of removing 80% or more of the cation molecules from the membrane. The removal of the cation molecule is performed by immersing the obtained membrane in an acid aqueous solution. Other points regarding the removal step are the same as those in the first embodiment, and thus the description thereof is omitted.
However, in this removal step, it is important to selectively remove only the cationic molecules and not remove the first cross-linking agent as much as possible. Since the cross-linking mechanism of the first cross-linking agent is the same as the formation mechanism of the anion / cation complex, the cross-linking agent molecule itself may flow out of the membrane by acid immersion. In order to avoid such outflow, it is necessary to select a cationic molecule / crosslinking agent and to optimize the immersion conditions in acid.
In the selection of the cation molecule and the crosslinking agent, those that easily flow out as cationic molecules (small molecular weights, such as tetramethylammonium chloride), and those that do not easily flow out as crosslinking agents (large molecular weights, such as 4 , 4′-di [trimethylammonium chloride] biphenyl, etc.).
Moreover, as an immersion condition in an acid, only a cation molecule can be selectively removed by optimizing the acid solution (acid concentration, solvent, temperature) and the immersion time.
When a solution containing the first crosslinking agent is cast to form a film and only the cation molecules are selectively removed, the protonic acid group of the solid polymer electrolyte and the cation portion of the first crosslinking agent cause a cation / anion interaction. , Crosslinks (ionic crosslinks) are formed between the polymer chains.

  Next, a high proton conductive electrolyte membrane and a method for manufacturing the same according to a third embodiment of the present invention will be described. The method for producing a high proton conductive electrolyte membrane according to the present embodiment includes a complex formation step, a membrane formation step, a removal step, and a crosslinking introduction step. In addition, the high proton conductive electrolyte membrane according to the present embodiment is obtained by the method according to the present embodiment. Among these, the complex forming process, the film forming process, and the removing process are the same as those in the first embodiment, and thus the description thereof is omitted.

The cross-linking introduction step is a step of introducing a cross-linked structure into the film by impregnating the second cross-linking agent into the film after removing the cationic molecules.
Specifically, as the second crosslinking agent,
(1) a crosslinking agent capable of introducing ionic crosslinking (that is, the same kind as the first crosslinking agent),
(2) covalent cross-linking _{(e.g., -SO 2 NHSO 2 -, -} SO 2 NHCO -, - CONHCO- etc.) can introduce crosslinking agent,
and so on.
Specific examples of the crosslinking agent capable of introducing covalent bond crosslinking include those represented by the formulas (4) to (7). These crosslinking agents may be used alone or in combination of two or more.

The cross-linked structure is introduced by impregnating a solution containing the second cross-linking agent into the film and causing a cross-linking reaction between the second cross-linking agent and the polymer chain. As the reaction conditions, optimum conditions are selected according to the type of the second crosslinking agent.
For example, when the second crosslinking agent is a crosslinking agent capable of introducing ionic crosslinking, it is only necessary to impregnate the membrane from which the cation molecules have been removed with the second crosslinking agent. As a result, the proton acid group of the solid polymer electrolyte and the cation portion of the second cross-linking agent cause a cation / anion interaction, and an ionic cross-link is formed between the polymer chains.
Further, for example, when the second cross-linking agent is perfluoroalkyldisulfonylamide and the protonic acid group contained in the membrane is a sulfonic acid group, the membrane is previously immersed in thionyl chloride and the sulfonic acid group (—SO2 ₃ H) is converted to a sulfonyl chloride group (—SO ₂ Cl). Next, when this membrane is impregnated with a perfluoroalkyldisulfonylamide / triethylamine solution, the sulfonyl chloride group and the sulfonylamide group react in the membrane, and covalent bond crosslinking (—SO ₂ NHSO ₂ —) occurs between the polymer chains. Is formed.
The same applies to the case of using another second cross-linking agent. If necessary, the proton acid group in the membrane is converted into a functional group capable of reacting with the second cross-linking agent, and then the second cross-linking agent is used in the membrane. Should be introduced. Moreover, the introduction of the crosslinked structure by the second crosslinking agent may be used alone or in combination with the introduction of the crosslinked structure by the first crosslinking agent.

  Next, the operation of the high proton conductive electrolyte membrane and the manufacturing method thereof according to the present invention will be described. The cast method is a method of casting a solution containing a polymer electrolyte on a substrate and removing the solvent, and is a conventional standard method for producing a polymer electrolyte membrane. When an electrolyte membrane is formed by the casting method, protonic acid groups associate to form a proton conduction path in the membrane. However, since the size of the proton conduction path obtained by the casting method is relatively small, this method has a limit in the reachable proton conductivity.

On the other hand, when the solid polymer electrolyte and the cation molecule are dissolved in the solvent, the proton of the proton acid group and the cation molecule are ion-exchanged to form an anion / cation complex. Next, when the solution containing the solid polymer electrolyte into which the anion / cation complex is introduced is cast into a film, as shown in FIG. 1A, the anion (from the proton acid group) bonded to the terminal of the polymer chain 12 is formed. It is considered that an anion / cation complex composed of 12a and a cation molecule 14 is associated. Further, when 80% or more of the cation molecules 14 are removed from the electrolyte membrane 10, as shown in FIG. 1B, a continuous hole 10 a having a size almost equal to that of the cation molecules 14 is formed inside the electrolyte membrane 10. . The continuous hole 10a functions as a proton conduction path in proton conduction, but its size is larger than that in the case of simply casting an electrolyte. Therefore, high proton conductivity can be obtained as compared with the conventional method.
Furthermore, when a crosslinked structure is introduced into a film having such continuous holes 10a, the continuous holes 10a are more firmly fixed. Therefore, even if the membrane repeatedly swells and contracts, a relatively high proton conductivity can be maintained.

  The method according to the present invention is a simple method in which cationic molecules are dissolved in a solution containing a polymer electrolyte in the case of forming a film by a casting method, and has a feature that high proton conductivity can be obtained thereby. . Moreover, it is applicable also to all the electrolytes which can be formed into a film by the casting method. Furthermore, if the manufacturing conditions are optimized, an electrolyte membrane having a proton conductivity higher by 20% or more than that obtained by simply casting the electrolyte into a membrane can be obtained.

Example 1
0.1108 g of sulfonated polyetheretherketone (S-PEEK) was weighed and dissolved and stirred in 4 mL of DMAc (solution A). To this solution A, 0.1019 g of tetrabutylammonium bromide was added and further stirred (solution B). Solution B was poured into a petri dish having a diameter of 48.5 mm, placed on a horizontal table in a draft, and left at room temperature for 3 days. When the DMAc was almost gone, the petri dish was vacuum dried (60 ° C., 2 hours).
Next, in order to remove excess DMAc, the membrane was peeled off from the petri dish and washed with 1N hydrochloric acid (overnight with slow stirring, then stirred for 2 hours instead of fresh hydrochloric acid). Furthermore, washing with ion-exchanged water (slow stirring for 1 hour × 3 times) was performed, followed by vacuum drying (140 ° C., 2 hours).
Next, in order to remove tetrabutylammonium bromide, the membrane was washed (40 ° C., slowly stirred, 24 hours) in EtOH / HCl mixed solution (EtOH / HCl = 9/1). Further, washing with ion-exchanged water (slow stirring for 1 hour × 3 times) was performed, followed by vacuum drying (60 ° C., overnight).
(Example 2)
An electrolyte membrane was prepared according to the same procedure as in Example 1 except that butylamine was used instead of tetrabutylammonium bromide.
(Example 3)
An electrolyte membrane was prepared according to the same procedure as in Example 1 except that hexylamine was used instead of tetrabutylammonium bromide.

Example 4
The membrane obtained by the method of Example 1 was immersed in phosphorus pentachloride / thionyl chloride (4 vol./1 vol.) Overnight at room temperature to convert sulfonic acid groups in the membrane to sulfonyl chloride groups. Next, the membrane was immersed in perfluoropropanedisulfonylamide (0.78 mg) / triethylamine (1 ml) / THF (100 ml) overnight at 50 ° C. to form a bridge via a sulfonimide group between the polymer chains. A film was obtained. Next, the membrane was washed in 1N hydrochloric acid (room temperature, 3 hours x 3 times), further washed with ion-exchanged water (room temperature, 1 hour x 3 times), and vacuum-dried (60 ° C, overnight) to introduce crosslinking. An electrolyte membrane was obtained.
(Comparative Example 1)
An electrolyte membrane consisting only of S-PEEK was used for the test.

  About the film | membrane obtained in Examples 1-4 and the comparative example 1, the equivalent weight (EW: Equivalent Weight), the moisture content, and the electrical conductivity were measured. Table 1 shows the results. From Table 1, the equivalent weights of the membranes obtained in Examples 1 to 4 are almost the same as in Comparative Example 1, whereas the water content and electrical conductivity are both improved from Comparative Example 1. I understand. This is because cation molecules such as tetraammonium bromide were added to the solution during casting, and the cation molecules were removed from the membrane after film formation, so a relatively large proton conduction path was formed in the membrane. Conceivable.

  Next, the membranes obtained in Examples 1 and 4 and Comparative Example 1 were subjected to a boiling / drying cycle test. Boiling / drying was performed 10 cycles, with one cycle consisting of boiling the membrane with water (1 hour) and vacuum drying (60 ° C., 3 hours). The proton conductivity (25 ° C. in water) after the cycle test was compared with that before the test, and the influence on proton conductivity due to repeated swelling and drying was investigated. Table 2 shows the results. In Example 1, when the swelling / drying by the test was repeated, the proton conductivity was lowered due to the breakage of the formed structure, but in Example 4, no decrease was caused.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

  A high proton conductive electrolyte membrane and a method for producing the same according to the present invention include a polymer electrolyte fuel cell, a water electrolysis device, a hydrohalic acid electrolysis device, a salt electrolysis device, an oxygen and / or hydrogen concentrator, a humidity sensor, and a gas sensor. It can be used as an electrolyte membrane used for various electrochemical devices such as the above and a method for producing the same.

FIG. 1A is a schematic cross-sectional view immediately after formation of an electrolyte membrane having an anion / cation complex, and FIG. 1B is a schematic cross-sectional view of the electrolyte membrane after removal of cationic molecules.

Explanation of symbols

10 solid polymer electrolyte membrane 12 polymer chain 12a anion 14 cation

Claims (7)

A complex forming step of dissolving a solid polymer electrolyte and a cation molecule in a solvent to form an anion / cation complex;
Casting the solution obtained in the complex formation step into a film, and forming a film; and
And a removal step of removing 80% or more of the cationic molecules from the membrane.   The solid polymer electrolyte includes a polyarylene-based or polyazole-based polymer, and a protonic acid group is introduced into any one or more of an aromatic ring and a heterocyclic ring included in the polymer. A method for producing the high proton conductive electrolyte membrane as described.   3. The high proton conductivity according to claim 1, wherein the cationic molecule is at least one selected from an amine compound, an ammonium salt, an imidazole derivative, a pyridine derivative, a quinoline derivative, a pyridazine derivative, a pyrimidine derivative, and a pyrazine derivative. For producing a conductive electrolyte membrane.   In the complex formation step, 50% or more and 150% or less of the cation molecules in an amount capable of converting all protonic acid groups contained in the solid polymer electrolyte into an anion / cation complex are dissolved in the solvent. The method for producing a high proton conductive electrolyte membrane according to any one of claims 1 to 3.   The cross-linking agent adding step of adding a first cross-linking agent having two or more cation moieties to the solution obtained in the complex forming step before the film forming step is further provided. The manufacturing method of the high proton conductive electrolyte membrane in any one.   The high proton conduction according to any one of claims 1 to 5, further comprising a cross-linking introduction step of impregnating the second cross-linking agent into the membrane and introducing a cross-linking structure into the membrane after the removing step. For producing a conductive electrolyte membrane. A high proton conductive electrolyte membrane obtained by the method according to claim 1.

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