JP2007042581A - Manufacturing method of solid electrolyte dope, solid electrolyte film and its manufacturing method, electrode membrane assembly, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a solid electrolyte film having a constant quality and superior ion conductivity by continuously forming film of a dope in which a solid electrolyte is dissolved in a solvent. <P>SOLUTION: A solid electrolyte dried beforehand by a drier 55 and a solvent which is refined beforehand by a refiner and removed of water and other impurities are mixed and made a mixed liquid 16. After the solid electrolyte is dissolved and made into a solution, it is filtered and made a dope 24. This dope 24 is made to flow and cast from a casting die 81 to a moving casting band 82. The cast film is separated from the casting band 82 as a film 62 containing the solid electrolyte. Then, this is dried by a tenter 66 and in a drying chamber 69. By this method, the solid electrolyte can be manufactured continuously and stably with uniform quality, does not contain impurities, and develops superior ion conductivity when used for a fuel cell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a solid electrolyte dope, a solid electrolyte film and a method for producing the same, an electrode membrane composite using the solid electrolyte film, and a fuel cell.

  In recent years, lithium ion batteries and fuel cells that can be used as a power source for portable devices and the like have been actively researched, and active research has also been conducted on solid electrolytes that are members thereof. The solid electrolyte is, for example, a lithium ion conductive material or a proton conductive material.

  Generally, there are film-like proton conductive materials, and a film-like solid electrolyte for use as a solid electrolyte layer of a battery such as a fuel cell and a method for producing the same have been proposed. The solid electrolyte is required to have high ion conductivity and durability.

  As a method for producing a film-shaped solid electrolyte, for example, Patent Document 1 proposes a method of immersing a polyvinylidene fluoride resin in a mixed solution of an electrolyte and a plasticizer. Patent Document 2 proposes a method for producing a proton conductive membrane by synthesizing an inorganic compound in a solution containing an aromatic polymer material having a sulfonic acid group and removing the solvent. . In this method, silicon oxide, phosphoric acid derivatives and the like are added to improve pores. In Patent Document 3, a method for producing an ion exchange membrane by adding a metal oxide precursor to a solution containing an ion exchange resin, casting a liquid obtained by subjecting the precursor to hydrolysis and polycondensation reaction, and the like. Has been proposed.

  In Patent Document 4, a polymer film having proton conductivity is produced by a solution casting method, that is, a solution casting method, and this film is immersed in an organic compound aqueous solution that is soluble in water and has a boiling point of 100 ° C. or higher. Thus, a method of producing a proton conducting membrane by causing equilibrium swelling and evaporating water by heating has been proposed. In Patent Document 5, a method of obtaining a solid electrolyte membrane by dissolving a compound mainly composed of polybenzimidazole having an anionic ionic group in an alcohol solvent having a boiling point of 90 ° C. or higher containing tetraalkylammonium hydroxide. Has been proposed. Patent Document 6 proposes a polymer composition mainly composed of a sulfonated polyarylene, a tetrafluoroethylene copolymer having proton conductivity, and an organic solvent, and this polymer composition is cast. It is described that the film is formed into a proton conductive membrane by a method, that is, a solution casting method. Patent Document 6 states that this proton conducting membrane has high ionic conductivity and does not deteriorate with time.

By the way, as a method for forming a polymer into a film, there are a melt film forming method and a solution film forming method as well known. The former can produce a film without using a solvent, but there are problems that the polymer is modified by heating and impurities in the raw polymer remain in the film as they are. On the other hand, although the latter has problems in equipment such as solution production equipment and solvent recovery equipment, the temperature during heating may be low, and it is possible to remove impurities in the polymer in the solution production process. There is. Furthermore, the latter also has an advantage that a film excellent in flatness and smoothness can be produced as compared with the former film. Therefore, a solid electrolyte film is produced by a solution casting method, and the solvent of the solution used for casting is a mixture of a first compound that is a poor solvent and a second compound that is a good solvent, A method has been proposed in which the weight is 10% by weight or more based on the first compound (see Patent Document 7).
JP-A-9-320617 JP 2001-307752 A JP 2002-231270 A JP 2004-79378 A JP 2004-131530 A JP 2002-37966 A Japanese Patent Laid-Open No. 2005-248128

  However, in patent document 1, the solution casting method is denied and the problem that the impurities contained in the raw material remain in the film is not solved. The methods of Patent Documents 2 to 5 are all manufacturing methods on a small scale, and are not considered methods for mass production. And the method of patent document 2 has the problem that dispersion | distribution of the composite_body | complex which consists of a polymer and an inorganic compound is difficult. The method of Patent Document 3 has a problem that the film forming process is complicated. Patent Document 4 has a problem that pores are generated in a film when immersed in water and a uniform film cannot be obtained, and a method for solving this problem is not described. Further, although it is described that various kinds of solid electrolyte films can be produced by the solution casting method, there is no description of a specific method. Patent document 5 limits the raw material to be used, and does not describe that it can be manufactured using other materials having excellent performance. About the polymer composition of patent document 6, the specific conditions of solution casting are not described. According to the method of Patent Document 7, there is no specific description or suggestion regarding the method of application to mass production or continuous production.

  In determining the conditions for solution casting, it is usually considered that the chemical structure and physical properties of the polymer contained in the liquid to be cast must be taken into account. Therefore, it is necessary to make it suitable for casting. In particular, when a long film is produced by continuously performing solution casting, if the properties of the liquid to be cast and the properties of the raw material are not taken into account, the film may be uneven and lack flatness, or The film formation itself may be difficult. In that sense, none of Patent Documents 2 to 6 specifically describes how to make a liquid to be cast.

  Accordingly, the present invention provides a solid electrolyte film that is continuously formed into a film, having a constant quality and excellent ion conductivity and durability, a method for stably and continuously producing the solid electrolyte film, and the film It is an object of the present invention to provide a method for producing a dope used for production, and an electrode membrane composite and a fuel cell using the solid electrolyte.

  Therefore, the method for producing a solid electrolyte dope of the present invention includes a drying step for drying a solid electrolyte, a purification step for purifying the solvent, a mixed solution obtained by mixing the solid electrolyte that has undergone the drying step and the solvent that has undergone the purification step. A mixing step, a dissolution step in which the solid electrolyte is dissolved in a solvent to make the mixed solution into a solution, and a filtration to obtain a solid electrolyte dope that is used for solution film formation by removing foreign matters by filtering the solution And a process.

  In the above production method, it is preferable to carry out a concentration step of concentrating the solution to increase the concentration of the solid electrolyte. In the drying step, the solid electrolyte is preferably dried by heating to 100 ° C. or higher. The purification step preferably has a moisture removal step of removing moisture previously contained in the solvent from the solvent. Furthermore, it is preferable that the water content of the solvent be 2% by weight or less in this water removal step.

  In the concentration step, it is preferable that the water content of the solution is less than 2% by weight. In the filtration step, the solution is preferably filtered by a filtration means having a pore diameter of less than 20 μm.

  The present invention also includes a mixing step of mixing a pre-dried solid electrolyte and a pre-purified solvent to form a mixed solution, and a dissolving step of dissolving the solid electrolyte in the mixed solution in a solvent to form a solution. A filtration step of removing foreign matters by filtering the solution to form a solid electrolyte dope, and casting the solid electrolyte dope onto a support to form a casting membrane. A solid electrolyte film manufacturing method comprising: a casting step of peeling off as a film; and a film drying step of drying the film.

  It is preferable that the manufacturing method of said solid electrolyte film has a concentration process which concentrates a solution and makes a solid electrolyte concentration high. The solid electrolyte is preferably dried by heating at 100 ° C. or higher. In the concentration step in which the water content of the solvent is preferably 2% by weight or less by refining the solvent, it is preferable to concentrate so that the water content in the solution is less than 2% by weight.

  Preferably, the compound that is a poor solvent for the solid electrolyte is the first solvent, and the compound that is a good solvent for the solid electrolyte is the second solvent, and the amount of the first solvent relative to the sum of the weights of the first and second solvents The weight is more preferably 10% or more and less than 100%. The second solvent preferably contains dimethyl sulfoxide, and the first solvent preferably contains an alcohol having 1 to 5 carbon atoms.

（ただし、ＸはＨ、ＹはＳＯ₂ 、Ｚは化４の（Ｉ）または（II）に示す構造であり、ｎとｍとは０．１≦ｎ／（ｍ＋ｎ）≦０．５を満たす。）

The solid electrolyte is preferably a hydrocarbon polymer, and the hydrocarbon polymer is more preferably an aromatic polymer having a sulfonic acid group. The aromatic polymer is represented by the general formula (I) It is more preferable that the copolymer is composed of structural units represented by (III) to (III). And this invention includes the solid electrolyte film obtained by the above method.

(However, X is H, Y is SO ₂ , Z is a structure shown in Chemical Formula (I) or (II), and n and m satisfy 0.1 ≦ n / (m + n) ≦ 0.5. .)

  Moreover, this invention is comprised including the solid electrolyte film manufactured by said method.

  The electrode membrane composite of the present invention comprises the above solid electrolyte film, an anode electrode that is provided in close contact with one surface of the solid electrolyte film, and generates protons from a hydrogen-containing substance supplied from the outside, A cathode electrode that is provided in close contact with the other surface of the solid electrolyte film and synthesizes water from protons that have passed through the solid electrolyte film and gas supplied from the outside is provided.

  Furthermore, the present invention comprises the above electrode membrane composite, and a current collector provided in contact with the electrode of the electrode membrane composite and for transferring electrons to and from the anode and cathode electrodes. The fuel cell includes the characteristic fuel cell.

  According to the present invention, it is possible to produce a dope suitable for continuously forming a solid electrolyte into a film, and continuously produce a solid electrolyte film having a constant quality and excellent ion conductivity and durability. be able to. And when the electrode membrane composite using this solid electrolyte is used for a fuel cell, this fuel cell exhibits an excellent electromotive force.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described here. First, the solid electrolyte film of the present invention will be described, and then the method for producing the film will be described.

[material]
In the present invention, a polymer having a proton donating group is used as a solid electrolyte to be formed into a film by the production method described later. The polymer having a proton donating group is not particularly limited, and a polymer having an acid residue and known as a proton conducting material can be used. Among them, preferred polymers are those having an acid residue, for example, an addition polymerization polymer compound having a sulfonic acid in the side chain, a sulfonated poly (meth) acrylate having a side chain phosphate group, and a polyether ether ketone. Examples include polyether ether ketone, sulfonated polybenzimidazole, sulfonated polysulfone obtained by sulfonated polysulfone, and sulfonated products of heat-resistant aromatic polymer compounds. Examples of the addition polymerization polymer compound having a sulfonic acid in the side chain include perfluorosulfonic acid represented by Nafion (registered trademark), sulfonated styrene, sulfonated polyacrylonitrile styrene, sulfonated polyacrylonitrile butadiene styrene, and the like. Examples of the sulfonated product of the heat resistant aromatic polymer include sulfonated polyimide.

  Preferable examples of perfluorosulfonic acid include substances described in, for example, JP-A-4-366137, JP-A-6-231777, and JP-A-6-342665. Is particularly preferred. However, in Chemical formula 5, m is 100 to 10000, 200 to 5000 is preferable, and 500 to 2000 is more preferable. And n is 0.5-100, and 5-13.5 is especially preferable. X is substantially equivalent to m, and y is substantially equivalent to n.

  Preferred examples of the sulfonated styrene, the sulfonated polyacrylonitrile styrene, and the sulfonated polyacrylonitrile butadiene styrene include the compounds described in JP-A-5-174856 and JP-A-6-1111834, and the substances shown in Chemical formula 6. Can be mentioned.

  Examples of the sulfonated product of the heat-resistant aromatic polymer include, for example, JP-A-6-49302, JP-A-2004-10777, JP-A-2004-345997, JP-A-2005-15541, JP-A-2005-15541. JP 2002-110174 A, JP 2003-100317 A, JP 2003-55457 A, JP 9345818 A, JP 2003-257451 A, JP 2000-510511 A, JP 2002-105200 A. Substances described in the gazette can be mentioned, and among them, the substances shown in Chemical Formula 3 and Chemical Formulas 7 and 8 below are particularly preferable.

  In particular, the film of the substance shown in Chemical Formula 3 achieves both the hygroscopic expansion coefficient and the proton conductivity. When n / (m + n) <0.1, there are too few sulfonic acid groups, and proton conduction paths, so-called proton channels may not be sufficiently formed. Therefore, the obtained film may not exhibit proton conductivity sufficient for practical use. In addition, when n / (m + n)> 0.5, the water absorbability of the film becomes high, so that the expansion coefficient due to water absorption, that is, the water absorption expansion coefficient increases, and the film is likely to deteriorate.

  The sulfonation reaction in the process of obtaining the above compound can be performed according to various synthetic methods in known literature. As the sulfonating agent, sulfuric acid (concentrated sulfuric acid), fuming sulfuric acid, gaseous or liquid sulfur trisulfide, sulfur trisulfide complex, amidosulfuric acid, chlorosulfonic acid and the like can be used. As the solvent, hydrocarbons (benzene, toluene, nitrobenzene, chlorobenzene, dioxetane, etc.), alkyl halides (methylene chloride, chloroform, dichloroethane, carbon tetrachloride, etc.) and the like can be used. The reaction temperature may be determined in the range of −20 ° C. to 200 ° C. according to the activity of the sulfonating agent. As another method, a mercapto group, a disulfide group, and a sulfinic acid group can be introduced into the monomer in advance, and a sulfonated product can be synthesized by an oxidation reaction with an oxidizing agent. At this time, hydrogen peroxide, nitric acid, bromine water, hypochlorite, hypobromite, potassium permanganate, chromic acid, etc. can be used as the oxidizing agent, and water, acetic acid, Propionic acid or the like can be used. The reaction temperature in this method may be determined in the range of room temperature (for example, 25 ° C.) to 200 ° C. according to the activity of the oxidizing agent. As yet another method, a sulfonated compound may be synthesized by introducing a halogenoalkyl group into the monomer in advance and performing a substitution reaction with sulfite, bisulfite, or the like. In this case, water, alcohols, amides, sulfoxides, sulfones and the like can be used as the solvent. The reaction temperature may be determined in the range of room temperature (for example, 25 ° C.) to 200 ° C. In addition, the solvent in the above sulfonation reaction may be a mixture in which two or more kinds of substances are mixed.

In the reaction step to the sulfonated product, an alkyl sulfonating agent may be used. As a general method, there is a Friedel-Crafts reaction using sultone and AlCl ₃ (Journal of Applied Polymer Science, Vol. 36, 1753-1767, 1988). When an alkyl sulfonating agent is used to perform the Friedel-Crafts reaction, hydrocarbons (benzene, toluene, nitrobenzene, acetophenone, chlorobenzene, trichlorobenzene, etc.), alkyl halides (methylene chloride, chloroform, dichloroethane, Carbon chloride, trichloroethane, dichloroethane, tetrachloroethane, etc.) can be used. The reaction temperature may be determined in the range of room temperature to 200 ° C. Note that the solvent in the reaction may be a mixture of two or more substances.

  In the case of producing a solid electrolyte film having the structure of Chemical Formula 3, a dope containing a polymer (hereinafter referred to as a precursor) in which X of Chemical Formula 3 is a cationic species other than H is prepared, and this is flowed on a support. Then, it is peeled off as a film containing a precursor (hereinafter referred to as a precursor film), and this precursor film is made of a polymer having a structure of chemical formula 3 by proton substitution and replacing the cationic species of X with H. A solid electrolyte film can be produced.

  The cationic species means an atom or atomic group that generates a cation when ionized. This cationic species need not be monovalent. As cations other than protons, alkali metal cations, alkaline earth metal cations, and ammonium cations are preferable, and calcium ions, barium ions, quaternary ammonium ions, lithium ions, sodium ions, and potassium ions are more preferable. In addition, even if a film is produced by leaving X in Chemical Formula 3 as a cationic species without using H, the film has a function as a solid electrolyte. However, the proton conductivity increases as the proportion of X cationic species substituted with H increases. In that sense, X is particularly preferably H.

As solid electrolyte, what has the following various performance is preferable. The ionic conductivity is preferably 0.005 S / cm or more, and more preferably 0.01 S / cm or more, for example, at 25 ° C. and a relative humidity of 70%. Further, the ionic conductivity after being immersed in a 50% aqueous methanol solution at 18 ° C. for one day is preferably 0.003 S / cm or more, more preferably 0.008 S / cm or more, and particularly with respect to before immersion. What the fall rate of the ionic conductivity after immersion is 20% or less is preferable. The methanol diffusion coefficient is preferably 4 × 10 ⁻⁷ cm ² / s or less, and particularly preferably 2 × 10 ⁻⁷ cm ² / s or less.

  As for strength, those having an elastic modulus of 10 MPa or more are preferred, and those having a modulus of 20 MPa or more are particularly preferred. The method for measuring the elastic modulus is described in detail in paragraph [0138] of JP-A-2005-104148, and the above value of the elastic modulus is a value obtained by a tensile tester manufactured by Toyo Baldwin. Therefore, when obtaining the elastic modulus using another test method or tester, it is preferable to obtain the correlation with the value obtained by the test method or tester in advance.

  Regarding durability, before and after the time-lapse test immersed in 50% methanol at a constant temperature, each change rate of weight, ion exchange capacity, and methanol diffusion coefficient is preferably 20% or less, preferably 15% or less. Some are particularly preferred. Further, before and after the time-lapse test in hydrogen peroxide, the rate of change in weight, ion exchange capacity, and methanol diffusion coefficient is preferably 20% or less, and particularly preferably 10% or less. Further, in 50% methanol, the volume swelling rate at a constant temperature is preferably 10% or less, and particularly preferably 5% or less.

  Further, those having a stable water absorption and water content are preferred. Moreover, it is preferable that it is so small that solubility is substantially negligible with respect to alcohols, water, and a mixed solvent of alcohol and water. Further, it is preferable that the weight loss and the shape change when immersed in the liquid are small enough to be substantially ignored.

  The ionic conduction performance of the solid electrolyte film is expressed by a so-called index which is a ratio between the ionic conductivity and the methanol permeability coefficient. And it can be said that the larger the index in a certain direction, the higher the ion conduction performance in that direction. In the thickness direction of the solid electrolyte film, the ionic conductivity is proportional to the thickness, and the methanol permeability coefficient is inversely proportional to the thickness. Therefore, the ionic conductivity of the solid electrolyte film can be controlled by changing the thickness. In a solid electrolyte film used for a fuel cell, an anode electrode is provided on one side and a cathode electrode is provided on the other side. Therefore, the index in the thickness direction of the solid electrolyte film is larger than the index in the other direction. Is preferred. The thickness of the solid electrolyte film is preferably 10 to 300 μm. For example, in the case of a solid electrolyte having both high ionic conductivity and methanol diffusion coefficient, it is particularly preferable to produce a film having a thickness of 50 to 200 μm, and a solid having both low ionic conductivity and methanol diffusion coefficient. In the case of an electrolyte, it is particularly preferable to produce a film so that the thickness is 20 to 100 μm.

  The heat resistant temperature is preferably 200 ° C. or higher, more preferably 250 ° C. or higher, and particularly preferably 300 ° C. or higher. The heat-resistant temperature here means a temperature that reaches 5% weight loss when heated at a rate of 1 ° C./min. Note that this weight reduction is calculated excluding the amount of evaporation such as moisture.

Furthermore, when a solid electrolyte is used as a film for a fuel cell, the solid electrolyte is preferably a solid electrolyte having a maximum output density of 10 mW / cm ² or more.

  By using the above solid electrolyte, it is possible to produce a solution suitable for production of a film, and it is possible to produce a solid electrolyte film suitable for a fuel cell. The solution suitable for the production of the film is, for example, a solution having a relatively low viscosity and easily removing foreign matters by filtration. The obtained solution is referred to as a dope in the following description.

  The dope solvent may be an organic compound that can dissolve the polymer as the solid electrolyte. Examples include aromatic hydrocarbons (eg, benzene, toluene, etc.), halogenated hydrocarbons (eg, dichloromethane, chlorobenzene, etc.), alcohols (eg, methanol, ethanol, n-propanol, n-butanol, diethylene glycol, etc.), Ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.), ethers (eg, tetrahydrofuran, methyl cellosolve, etc.), and nitrogen-containing compounds (N-methylpyrrolidone, N, N-dimethylformamide (DMF), N, N′-dimethylacetamide (DMAc) and the like), dimethyl sulfoxide (DMSO) and the like. The solvent may be a mixture obtained by mixing a plurality of substances.

  The dope solvent may be a mixture of a plurality of substances. When making a solvent into a mixture, it is preferable to set it as the mixture of the good solvent of a solid electrolyte, and a poor solvent. In the case of producing a solid electrolyte film having the structure of Chemical Formula 3, when protonation is carried out in the film production process, a mixture of a precursor good solvent and a poor solvent may be used as a solvent. Mix the solvent and the solid electrolyte so that the solid electrolyte is 5% by weight of the total weight, and determine whether the solvent used is a poor solvent or a good solvent based on the presence or absence of insoluble matter. can do. A good solvent for the solid electrolyte, that is, a substance that dissolves the solid electrolyte has a relatively high boiling point among the compounds generally used as the solvent, while the poor solvent has a boiling point among the compounds generally used as the solvent. Is the relatively low one. Therefore, by mixing the poor solvent with the good solvent, the efficiency and effect of removing the solvent in the film production process can be enhanced, and in particular, the drying efficiency of the cast film can be greatly improved.

  In a mixture of a good solvent and a poor solvent, the weight ratio of the poor solvent is preferably as large as possible, specifically 10% or more and less than 100%. More preferably, (weight of good solvent) :( weight of poor solvent) is 90:10 to 10:90. Thereby, since the ratio of the low boiling-point component in the weight of all the solvents becomes large, the drying efficiency and the drying effect in the manufacturing process of a solid electrolyte film can be improved more.

  As the good solvent component, DMF, DMAc, DMSO, and NMP are preferable. Among them, DMSO is particularly preferable in terms of safety and relatively low boiling point. As the poor solvent component, a so-called lower alcohol having 1 to 5 carbon atoms, methyl acetate, and acetone are preferable. Among them, a lower alcohol having 1 to 3 carbon atoms is more preferable, and when DMSO is used as a good solvent. Methyl alcohol is particularly preferred from the viewpoint of the most excellent compatibility with it.

  In order to improve various film characteristics when the solid electrolyte is used as a film, an additive can be added to the dope. Examples of the additive include an antioxidant, fibers, fine particles, a water absorbing agent, a plasticizer, and a compatibilizer. The addition rate of these additives is preferably in the range of 1% by weight to 30% by weight when the total solid content in the dope is 100% by weight. However, the addition rate and the type of substance do not adversely affect the ionic conductivity. The additive will be specifically described below.

  Antioxidants include (hindered) phenolic, monovalent or divalent sulfur, trivalent phosphorus, benzophenone, benzotriazole, hindered amine, cyanoacrylate, salicylate, oxalic acid anilide These compounds are listed as preferred examples. Specific examples thereof include compounds described in JP-A-8-53614, JP-A-10-101873, JP-A-11-114430, and JP-A-2003-151346.

  Preferred examples of the fibers include perfluorocarbon fibers, cellulose fibers, glass fibers, polyethylene fibers and the like, and specifically, JP-A-10-31815, JP-A-2000-231938, JP-A-2001-307545. Examples thereof include fibers described in JP-A-2003-317748, JP-A-2004-63430, and JP-A-2004-107461.

  Examples of the fine particles include titanium oxide and zirconium oxide, and specific examples include various fine particles described in JP-A Nos. 2003-178777 and 2004-217931.

  Water-absorbing agents, that is, hydrophilic substances include cross-linked polyacrylate, starch-acrylate, poval, polyacrylonitrile, carboxymethylcellulose, polyvinylpyrrolidone, polyglycol dialkyl ether, polyglycol dialkyl ester, synthetic zeolite, titania gel, zirconia gel And yttria gel are preferable examples, and specific examples thereof include water absorbing agents described in JP-A-7-135033, JP-A-8-20716, and JP-A-9351857.

  Preferred examples of the plasticizer include phosphate ester compounds, chlorinated paraffins, alkylnaphthalene compounds, sulfone alkylamide compounds, oligoethers, and aromatic nitriles. And plasticizers described in JP-A-2003-317539.

  As the compatibilizer, those having a boiling point or sublimation point of 250 ° C. or higher are preferable, and those having a boiling point or 300 ° C. or higher are more preferable.

  The dope may further contain various polymers for the purpose of (1) increasing the mechanical strength of the film and (2) increasing the acid concentration in the film.

  Among the above objects, a polymer having a molecular weight of about 10,000 to 1,000,000 and having a good compatibility with the solid electrolyte is suitable for (1). For example, perfluorinated polymers, polystyrene, polyethylene glycol, polyoxetane, polyether ketone, polyether sulfone, and polymers containing two or more polymer repeating units are preferred. Moreover, it is preferable to contain these substances in dope so that it may become the range of 1-30 weight% with respect to the total weight when it is set as a film. The compatibility with the solid electrolyte may be improved by using a compatibilizer. As the compatibilizer, those having a boiling point or sublimation point of 250 ° C. or higher are preferable, and those having a boiling point of 300 ° C. or higher are more preferable.

  Among the above objects, (2) is preferably a polymer having a ptronic acid moiety. Examples of such a polymer include perfluorosulfonic acid polymers such as Nafion (registered trademark), sulfonated polyetheretherketone having a phosphate group in the side chain, sulfonated polyethersulfone, sulfonated polysulfone, and sulfonated polybenzimidazole. Examples thereof include sulfonated products of heat-resistant aromatic polymer compounds such as Moreover, it is preferable to contain these substances in dope so that it may become the range of 1-30 weight% with respect to the total weight when it is set as a film.

  Further, when the obtained solid electrolyte film is used in a fuel cell, an active metal catalyst that promotes the oxidation-reduction reaction between the anode fuel and the cathode fuel may be added to the dope. As a result, the fuel that has permeated into the solid electrolyte film from one electrode is consumed in the solid electrolyte without reaching the other electrode, so that the crossover phenomenon can be prevented. The active metal catalyst is not particularly limited as long as it functions as an electrode catalyst, but platinum or an alloy based on platinum is particularly suitable.

[Dope production]
FIG. 1 shows a dope manufacturing facility. However, the present invention is not limited to the dope manufacturing apparatus and method shown here. The dope manufacturing facility 10 includes a solvent tank 11 for storing a solvent, a hopper 12 for supplying a solid electrolyte, an additive tank 15 for storing an additive, a solvent, a solid electrolyte, and an additive. A mixing tank 17 to be mixed into the mixed liquid 16, a heating device 18 for heating the mixed liquid 16, a temperature regulator 21 for adjusting the temperature of the heated mixed liquid 16, and a temperature regulator 21. A filtration device 22 for filtering the mixed liquid 16 that has exited, a flash device 26 for adjusting the concentration of the dope 24 from the filtration device 22, and a filtration device 27 for filtering the dope 24 whose concentration has been adjusted are provided. The dope manufacturing facility 10 further includes a recovery device 28 for recovering the solvent and a regeneration device 29 for regenerating the recovered solvent. The dope manufacturing facility 10 is connected to a film manufacturing facility 33 via a stock tank 32. In addition, although the valves 36-38 for adjusting the amount of liquid feeding and the pumps 41 and 42 for liquid feeding are provided in the dope manufacturing equipment 10, about the increase / decrease in the position and number where these are arrange | positioned It is changed appropriately.

  When the dope manufacturing facility 10 is used, the dope 24 is manufactured by the following method. By opening the valve 37, the solvent is sent from the solvent tank 11 to the mixing tank 17. Next, the solid electrolyte is fed into the mixing tank 17 from the hopper 12. At this time, the solid electrolyte may be continuously fed to the mixing tank 17 by sending means for continuously measuring and sending, or may be fed to the mixing tank 17 by sending means for weighing and sending a predetermined amount. It may be sent intermittently. In addition, the required amount of the additive solution is sent from the additive tank 15 to the mixing tank 17 by opening and closing the valve 36.

  In addition to the method of sending the additive as a solution, for example, when the additive is liquid at room temperature, the additive can be fed into the mixing tank 17 in the liquid state. Further, when the additive is solid, a method of feeding into the mixing tank 17 using a hopper or the like is also possible. When a plurality of types of additives are added, a solution in which a plurality of types of additives are dissolved can be placed in the additive tank 15. Alternatively, it is also possible to use a plurality of additive tanks and put a solution in which the additive is dissolved in each of them and send them to the mixing tank 17 through independent pipes.

  In the above description, the order of putting in the mixing tank 17 is the solvent, the solid electrolyte, and the additive, but is not limited to this order. For example, a preferred amount of solvent can be fed after the solid electrolyte is fed into the mixing tank 17. In addition, the additive is not necessarily limited to mixing the solid electrolyte and the solvent in the mixing tank 17, and may be mixed into the mixture of the solid electrolyte and the solvent in an in-line mixing method or the like in a later step.

  The mixing tank 17 includes a jacket 46 that encloses the outer surface thereof and is supplied with a heat transfer medium between the mixing tank 17, a first stirrer 48 that is rotated by a motor 47, and a second stirrer 52 that is rotated by a motor 51. It is preferable that it is attached. The temperature of the mixing tank 17 is adjusted by a heat transfer medium flowing into the inside of the jacket 46, and a preferable temperature range is −10 ° C. to 55 ° C. By appropriately selecting and using the types of the first stirrer 48 and the second stirrer 52, the mixed liquid 16 in which the solid electrolyte is swollen with the solvent is obtained. The first stirrer 48 preferably has an anchor blade, and the second stirrer 52 is preferably a dissolver type eccentric stirrer.

  Next, the liquid mixture 16 is sent to the heating device 18 by the pump 41. The heating device 18 is preferably a jacketed tube having a tube main body (not shown) and a jacket for passing a heat transfer medium between the tube main body, and further pressurizing the mixed liquid 16. It is preferable to have a part (not shown). By using such a heating device 18, the solid content in the mixed solution 16 can be effectively and efficiently dissolved under heating conditions or pressure heating conditions. Hereinafter, such a method of dissolving a solid component in a solvent by heating is referred to as a heating dissolution method. In the heating dissolution method, it is preferable to heat the mixed solution 16 so as to be 60 ° C to 250 ° C.

  Note that the solid component may be dissolved in a solvent by a cooling dissolution method instead of the heating dissolution method. The cooling dissolution method is a method of proceeding dissolution while cooling the mixed solution 16 so that the temperature of the mixed solution 16 is maintained or lower. In the cooling dissolution method, the mixed solution 16 is preferably cooled to a temperature of −100 ° C. to −10 ° C. The solid electrolyte can be sufficiently dissolved in the solvent by the heating dissolution method or the cooling dissolution method as described above.

  After the mixed liquid 16 is brought to about room temperature by the temperature controller 21, it is filtered by a filtration device 22 to remove foreign matters such as impurities and aggregates to obtain a dope 24. The filter used in the filtration device 22 preferably has an average pore diameter of 50 μm or less.

  The dope 24 after filtration is sent to the stock tank 32 by the valve 38 and once stored, and then used for the production of a film.

  By the way, as described above, the method in which the solid component is once swollen and then dissolved to form a solution increases the time required for the dope production as the concentration of the solid electrolyte in the solution is increased. May be a problem. In such a case, it is preferable to once make a dope having a concentration lower than the target concentration and then carry out a concentration step to achieve the target concentration. For example, the dope 24 filtered by the filtering device 22 can be sent to the flash device 26 by the valve 38, and the dope 24 can be concentrated by evaporating a part of the solvent of the dope 24. The concentrated dope 24 is extracted from the flash device 26 by the pump 42 and sent to the filtration device 27. The temperature of the dope 24 during filtration is preferably 0 ° C to 200 ° C. The dope 24 from which foreign matter has been removed by the filtration device 27 is sent to the stock tank 32 and once stored, and then used for film production. In addition, since the concentrated dope 24 may contain bubbles, it is preferable to carry out a bubble removal process before sending it to the filtration device 27. As the bubble removal method, for example, various known methods such as an ultrasonic irradiation method for irradiating the dope 24 with ultrasonic waves are applied.

  Further, the solvent gas generated by the flash evaporation in the flash device 26 is condensed by the recovery device 28 having a condenser (not shown) and recovered as a liquid. The recovered solvent is regenerated and reused as a solvent for dope production by the regenerator 29. Such collection and recycling have advantages in terms of manufacturing costs and are effective in preventing adverse effects on the human body and the environment because they are implemented in a closed system.

  With the above manufacturing method, the dope 24 having a solid electrolyte concentration or a precursor concentration of 5 wt% or more and 50 wt% or less can be manufactured. The solid electrolyte concentration or precursor concentration is more preferably in the range of 10 wt% to 40 wt%. The concentration of the additive is preferably in the range of 1% by weight to 30% by weight when the total solid content in the dope is 100% by weight.

A method for producing a dope having a more preferable mode will be described below.
(Pre-mixing treatment of solid electrolyte and solvent)
The solid electrolyte is sufficiently dried in advance by the drying device 55. It can be dried by heating the solid electrolyte to 100 ° C. or more, but in order to dry the pellet-like or powder-like solid electrolyte uniformly and uniformly, rather than standing and heating, Heating with stirring is preferred. As the heating device 55 for heating while stirring, a paddle dryer is preferable.

  The solvent is purified by the purification device 56. In this purification step, moisture and impurities contained in the solvent are removed. Examples of the purification device 56 include a distillation device (fractional distillation device). When a multistage distillation apparatus is used as the distillation apparatus, water and other impurities are separated from each other, which is efficient when post-treatment for each impurity. In addition, when a multistage distillation apparatus is used, the distillation conditions can be precisely controlled. Therefore, the distillation conditions can be changed for each solvent in different lots, and energy consumption can be saved.

  As described above, by sufficiently removing moisture from the solid electrolyte and the solvent in advance, gelation of the solid electrolyte in the dope 24 is suppressed. The lower the moisture content of the solvent, the better. However, in consideration of the relationship between the purification accuracy of the purification device 56, the purification efficiency, and the occurrence of gelation, 2% by weight can be said to be the upper limit. Furthermore, according to the above method, impurities other than water can be removed in the solvent purification step, so that when the obtained dope is used as a solid electrolyte member of a fuel cell, ion conduction may be inhibited. It has the effect of disappearing. According to the present embodiment, not only the water is removed from the solid electrolyte and the solvent, but also the moisture is removed from the dope 24 by the above flash device, so that the effect of preventing gelation is further improved. Note that the moisture content of the dope is reduced to less than 2 wt% by the flash device.

(Heat dissolution method)
First, a solid electrolyte is gradually added to a solvent with stirring at a temperature around room temperature, specifically, −10 to 55 ° C. This step can be performed, for example, in the mixing tank 17 in FIG. When a mixture of a plurality of substances is used as the solvent, the mixing order of each component of the solvent and the solid electrolyte is not particularly limited. For example, after adding a solid electrolyte in the main solvent, a first method of adding another solvent (for example, a swelling solvent such as alcohol), the solid electrolyte is preliminarily mixed with the swelling solvent to obtain a swollen product, and then There is a second method of adding other solvents such as the main solvent. Such first and second methods are effective in preventing non-uniform dissolution. Thus, in the present invention, it is preferable to swell the solid electrolyte in advance. In order to carry out the swelling more efficiently, it is preferable to provide a jacket through which the heat transfer medium passes on the outer periphery of the mixing tank 17 and continuously supply the temperature-controlled heat transfer medium into the jacket. Note that the solid electrolyte may be swollen in advance with two or more solvents, and then the remaining solvent may be added. In this swelling step, dissolution time can be further shortened by applying pressure or reducing pressure. In order to carry out pressurization and decompression, a pressure-resistant container or line is used.

  A method of mixing a solid electrolyte and its poor solvent into a mixture, and mixing the good solvent of the solid electrolyte into the mixture without separating the poor solvent, and improving the work efficiency and reducing the risk. This is effective for improving productivity. In this case, the ratio between the solid electrolytic weight and the total solvent amount is preferably 5 to 40% by weight. The apparatus for preliminarily mixing the solid electrolyte and the poor solvent can be used without limitation as long as it is a container with a general stirrer, but when the mixing ratio of the poor solvent to the solid electrolyte is small, a kneader or an extruder is used. A pressure-resistant container of a closed type and sent out while kneading is preferable. Examples of the stirring means provided in this type and imparting a shearing force include propeller type, turbine type, paddle type, spiral type, anchor type and the like. In addition, when mixing a mixture of a solid electrolyte and a poor solvent and a good solvent, the good solvent may be added to the mixture and dissolved. However, adding the mixture into the good solvent shortens the dissolution time. It is preferable because it is possible.

  Next, the liquid mixture 16 is heated to 60 to 250 ° C. under a pressure of 0.2 MPa to 30 MPa. The heating temperature is more preferably 60 to 220 ° C. In addition, this process can be performed with the heating apparatus 18 in FIG. Heating can be performed using, for example, high-pressure steam or an electric heat source. In order to achieve the above-described pressure condition, a pressure vessel and a pressure line are required, but the material is not particularly limited, and may be iron, stainless steel, other metals, or the like.

  Furthermore, carbon dioxide may be enclosed in a mixed liquid that is at high temperature and high pressure to form a so-called supercritical liquid. In this case, the ratio of carbon dioxide to the solvent is preferably 5/95 to 70/30, more preferably 10/90 to 60/40.

  Since the solution heated as described above has a high temperature, it is not cast as it is, but is cooled before casting. Specifically, the solvent is cooled to a temperature not higher than the lowest boiling point of the used solvents. For example, it is cooled to −10 to 55 ° C. and returned to normal pressure. Such a cooling process can be implemented by the temperature regulator 21 in FIG. The cooling may be performed by simply leaving the high-pressure and high-temperature container or line containing or passing the mixed liquid 16 at room temperature, but may be cooled by a coolant such as cooling water.

  In addition, in order to improve the dissolution efficiency of a solid electrolyte, you may repeat said heating process and cooling process. Whether or not the dissolution is sufficient can be determined by simply observing the appearance of the liquid visually. In such a heating and dissolving method, it goes without saying that a sealed container is used in order to avoid evaporation of the solvent.

Moreover, in order to suppress generation | occurrence | production of an undissolved substance, a gel, etc. even when performing casting at high speed, it replaces with the heating apparatus 18 and uses a tank (not shown), and mixes the liquid mixture 16 to the mixing tank 17 for 1 minute or more. There is a method in which the mixture is retained, mixed and swollen, and sent to the tank provided instead to be completely dissolved and homogenized. In that case, the following three conditions (1) to (3) are more preferable conditions.
(1) The particle diameter d0 of the solid electrolyte supplied to the mixing tank 17 is set to 5 × 10 ⁻² mm ≦ d0 ≦ 20 mm.
(2) The temperature at the end of heating (T2) in the tank provided in place of the heating device 18 and the temperature (T1) before mixing in this tank are both the lowest of the boiling points of the solvents in the gas mixture 16. The boiling point is higher than the pressure.
(3) After supplying the mixed solution 16 to a tank provided instead of the heating device 18, the peripheral speed of the stirring blade of the stirrer provided in the tank is set to 0.5 m / sec or more and stirred for 30 minutes or more.

  The mixing tank 17 is preferably compact and excellent in dispersibility. Moreover, as a tank instead of the heating device 18, a pressure resistant tank is preferable. This is because pressure is applied to the tank instead of the heating device 18 because the temperature may be higher than the boiling point of the solvent. Furthermore, when sending the mixed solution 16 from the mixing tank 17 to the tank instead of the heating device 18, it is necessary to send the mixed solution 16 at a pressure higher than the pressure in the tank. Therefore, in order to suppress the generation of aggregates and shorten the entire time required for dissolution, the mixed solution 16 is injected. Specifically, there are a method of feeding using a pressurizing pump and a method of feeding while pressurizing with nitrogen gas, and a method of feeding while mixing and dispersing such as a kneader or an extruder is more preferable. Note that the mixing tank 17 itself may have a function like an extruder. The tank instead of the heating device 18 may be a pressure-resistant sealed container, but the temperature in the container can be increased by 40 to 50 ° C. higher than the boiling point of the lowest boiling solvent among the solvents used, and Those that can withstand pressure are preferred. When sending from the mixing tank 17 to the tank instead of the heating device 18, it is preferable that the temperature of the mixed solution 16 in the tank instead of the heating device 18 is set to be equal to or higher than the boiling point of the solvent in advance. It is possible to suppress the generation of agglomerates and to extremely shorten the dissolution time. In the case where the tank instead of the heating device 18 is provided with a stirrer, it is preferable that the peripheral speed at the tip of the stirring blade of the stirrer be 0.5 m / sec or more, specifically, a propeller type , Turbine type, paddle type, spiral type, anchor type, disper type and the like can be used.

(Filtration process)
The mixed solution 16 is made into a dope 24 by removing foreign matters such as undissolved matter, dust, and impurities by using a filter 22 and various filters such as a wire mesh and a flannel. The absolute filtration accuracy of the filter of the filtration device 22 is preferably 0.1 μm or more and 50 μm or less, and more preferably 0.5 μm or more and less than 20 μm. The filtration pressure is preferably 16 × 10 N / cm ² or less, more preferably 12 × 10 N / cm ² or less, further 10 × 10 N / cm ² or less, and particularly preferably 2 × 10 N / cm ² or less.

  The viscosity of the mixed solution 16 when filtered is preferably 10,000 P or less, more preferably 1000 P or less, still more preferably 500 P, and particularly preferably 100 P or less. The material of the filter may be a known material such as glass fiber, cellulose fiber, filter paper, fluororesin such as tetrafluoroethylene resin, but ceramics, metal, and the like are more preferable. The filter may be a surface type or a depth type, but the depth type is more preferable because it is relatively less clogged.

  During the manufacture of the dope, the flow rate of each solution, for example, the mixed solution 16 or the dope 24 may be changed. In such a case, the foreign matter trapped in the filter may flow out into the dope 24 due to a change in flow rate. Therefore, before changing the flow rate, the maximum flow rate of the liquid is maintained, the primary flow rate is maintained, and the filter is passed through the filter. May be returned to the upstream of the filtration device and then changed to a predetermined flow rate. This method can also be applied to other filtration devices other than the filtration device 22.

  A plurality of filtration devices 22 are preferably provided in parallel. As a result, switching can be used. Even at the start of use due to such switching, foreign matter as described above may be mixed into the dope 24. Therefore, it is preferable to suppress foreign matter outflow by the same method as the processing before the flow rate change. The same applies to other filtration devices other than the filtration device 22.

Although illustration is omitted, it is preferable to filter the additive solution before in-line mixing even when the additive solution is added in-line. About the filtration process of an additive liquid, it is preferable to satisfy | fill at least any one of the following conditions.
-The additive solution is filtered through two or more depth filters, the number of times of filtration is 3-10 times,
-When eight kinds of 0.5 ppm aqueous dispersions of the test powder 1 specified in JISZ 8901 are filtered, a cartridge filter having a particle collection rate of 5 to 10 μm and 20 to 60% is used as an additive solution. Use as a filter to filter,
-After filtering with a thread-wound type first filter in which a long fiber is wound around a core made of polypropylene or stainless steel, the absolute filtration accuracy is 30 to 60 µm, and the porosity ε is 60 to 80% Filter with a metal second filter (for example, Finepore NF series NF-10, NF-12, NF-13, etc. manufactured by Nippon Seisen Co., Ltd.).
As a more preferred embodiment,
-The filtration flow rate per 1 cm ² of filter should be 10 ml / min or less,
-When filtering immediately before being added in-line, the filtration flow rate per 1 cm ² of the filter should be 1 ml / min or less,
-The pressure difference between the primary side and the secondary side in the filtration device is 200 kPa or less,
-The temperature of the additive liquid at the time of filtration shall be 30-110 degreeC,
When the additive liquid contains various fine particles such as silicon dioxide fine particles, the primary average particle diameter of the fine particles is 20 nm or less and the apparent specific gravity is 70 g / liter or more.

  When the surface type filter is used for a long time, the captured foreign substances come into contact with each other and grow greatly. And if the filter hole is clogged and the pressure rises too much, large foreign matter will pass through the filter. For this reason, foreign matter in the dope may be increased. Examples of the surface type include a filter paper pleated cartridge filter TC type manufactured by Advantech Toyo Co., Ltd. and a metal mesh used for a sieve. On the other hand, since the depth type filter is formed with a certain thickness, the possibility of contact between the captured aggregates is lower than that of the surface type. For this reason, gel-like aggregates and the like can be removed for a long period of time. Examples of the depth type include a wind cartridge filter TCW type manufactured by Advantech Toyo Corporation, a depth cartridge filter TCPD type, a fine pore NF series manufactured by Nippon Seisen Co., Ltd., and the like.

  When the in-line additive liquid contains an aggregate, the aggregate is a secondary aggregate or tertiary aggregate gel. In the membrane type filter (membrane cartridge filter TCF type manufactured by Advantech Toyo Co., Ltd., pleated cartridge filter TCPE type, etc.), such agglomerates are easily removed. Are preferred.

  Moreover, when sending an additive liquid to the metal filter just before in-line addition, as a pump for liquid feeding, a diaphragm pump, a plunger pump, etc. (Fuji Techno Kogyo Co., Ltd. plunger pump HYSA-16, JGC It is more preferable to use a reciprocating pump such as a mill flow control displacement pump (C23Y-1.5F-14D1D, etc.), and increase the number of cylinders to two or three. This can greatly reduce the load on the filter.

  In addition, it is preferable that an additive liquid is conveyed by a closed system until it adds in the liquid mixture 16 and dope 24 including a filtration process.

  The solid content such as the solid electrolyte remaining in the filter can be reused as a raw material. Further, by co-casting a plurality of individually filtered solid electrolyte dopes by the simultaneous casting method, a solid electrolyte laminated film having no boundary surface inside the film and having a smooth surface can be produced.

By carrying out the filtration process as described above, when a film is formed, foreign matter having a size exceeding 50 μm can be reduced to substantially 0 per 250 mm ² , and further, foreign matter having a size of 5 to 50 μm is 250 mm in area. ^The number can be 200 or less per two. The size and number of foreign substances are determined by the transmission measurement method of an optical microscope.

  In addition to the foreign matter contained in the dope, the foreign matter in the film includes a pinhole or the like due to bubbles remaining in the dope and remaining as it appears on the film surface. . Therefore, it is preferable that the dope 24 is defoamed before casting. The defoaming process will be described in detail below.

(Defoaming)
There is also a method of using a dope that has been subjected to the following steps (1) to (3) in order to eliminate bubbles of 0.3 μm or more in the film. In the following method, the temperature may be raised immediately after standing for 6 minutes or longer to complete the dissolution, or the standing time may be overnight or longer.
(1) Raise the temperature of the dope 24 to near the boiling point (bp) in the pressure vessel,
(2) Release the pressure inside the pressure vessel while standing at that temperature for 6 minutes or more,
(3) Then, the inside of the pressure vessel is sealed, and the temperature of the dope 24 is set to (b.p + 20) ° C. to (b.p + 50) ° C. under pressure.

  As a method for eliminating bubbles of 0.3 μm or more in the film, it is preferable to further add the following conditions. The flakes, that is, a solid electrolyte that is a large powder, an organic solvent, and the like are mixed in a pressure vessel and dissolved, and the standing time in (2) is set to 10 minutes or longer. In the meantime, release the pressure of the pressure vessel and expose it to the atmosphere. Then, after replacing the air in the upper space in the pressure vessel with the vapor of the organic solvent and allowing to stand for a predetermined time, b. The temperature is raised to p or more to complete the dissolution of the solid electrolyte. After cooling this, filtration is performed and a film is formed by the method described later. Thereby, the solid electrolyte film which does not contain a bubble can be obtained.

  In addition, it is preferable to degas | foam beforehand also about the additive liquid for making the liquid mixture 16, before mixing with a solid electrolyte etc. The same applies to the additive liquid added at a place other than the mixing tank 17. In particular, when there is equipment or time allowance, it is preferable to perform defoaming. Examples of the defoaming method of the additive liquid include a method of raising the temperature of the additive liquid placed in a container, a method of allowing the additive liquid to stand for a long time, a method of applying vibration to the additive liquid, and a method of combining these. In the method of applying vibration, it is preferable to apply strong vibration with a cycle as short as possible, and ultrasonic vibration is exemplified as such vibration. It is also effective to apply an ultrasonic wave by arranging an ultrasonic vibrator on a pipe through which the additive liquid passes or a filter for filtering the additive liquid. In that case, a vibrator may be attached to a metal part inside each pipe or filter. The vibration frequency of the vibration device is preferably 100 Hz to 40 kHz, and the frequency of the ultrasonic vibration element is preferably 10 to 40 kHz.

[Film production]
A method for producing a solid electrolyte film will be described. FIG. 2 is a schematic view of the film manufacturing facility 33. However, the present invention is not limited to the film manufacturing method and equipment as shown here. In the film manufacturing facility 33, a filtration device 61 for removing foreign substances from the dope 24 sent from the stock tank 32, and a dope 24 filtered by the filtration device 61 are cast to produce a solid electrolyte film (hereinafter simply referred to as a film). A casting chamber 63, 62, a tenter 64 that holds both side ends of the film 62 and dries while conveying the film 62, an edge-cutting device 67 that separates both side ends of the film 62, and a film 62. A drying chamber 69 for drying while being conveyed over a plurality of rollers 68, a cooling chamber 71 for cooling the film 62, a static eliminating device 72 for reducing the charge amount of the film 62, and embossing at the side end A knurling roller pair 73 for applying the film and a winding chamber 76 for winding the film 62 are provided.

  A stirrer 78 that is rotated by a motor 77 is attached to the stock tank 32, and precipitation and aggregation of the solid content of the dope 24 are suppressed by stirring. The stock tank 32 is connected to the filtration device 61 via the pump 80. The filter used for the filtration device 61 preferably has an average pore diameter of 10 μm or less. Thereby, it can prevent that the impurity which becomes a factor of deterioration of the initial performance of proton conductivity and a time-dependent deterioration of proton conductivity mixes in a film. The presence or absence of impurities such as insoluble matter can be visually evaluated by illuminating the dope sampled from the stock tank 32 with a fluorescent lamp.

The casting chamber 63 includes a casting die 81 that flows out of the dope 24, and a casting band 82 as a traveling support. As a material of the casting die 81, precipitation hardening type stainless steel is preferable, and its thermal expansion coefficient is preferably 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. And it has almost the same corrosion resistance as SUS316 in the forced corrosion test with electrolyte aqueous solution, and even if it is immersed in a mixed solution of dichloromethane, methanol and water for 3 months, pitting (opening) occurs at the gas-liquid interface. Those having corrosion resistance that do not occur are preferred. The casting die 81 is preferably produced by grinding a material that has passed for one month or more after casting, whereby the dope 24 uniformly flows inside the casting die 81, and the flow described later. Streaks and the like are prevented from occurring in the spread film 24a. The so-called wetted surface in contact with the dope 24 of the casting die 81 preferably has a finishing accuracy of 1 μm or less in terms of surface roughness and a straightness of 1 μm / m or less in any direction. The clearance of the slit of the casting die 81 can be adjusted in the range of 0.5 mm to 3.5 mm by automatic adjustment. The chamfer radius R of the corner portion of the liquid contact portion at the tip of the lip of the casting die 81 is constant and 50 μm or less over the entire width of the casting die 81. The casting die 81 is preferably a coat hanger type die.

  The width of the casting die 81 is not particularly limited, but is preferably about 1.1 to 2.0 times the width of the film 62 as the final product. In addition, a temperature controller that controls the temperature of the casting die 81 is preferably attached to the casting die 81 so that the temperature of the dope 24 during film formation is maintained at a predetermined temperature. Further, it is more preferable that the casting die 81 is provided with a plurality of thickness adjusting bolts (heat bolts) provided at a predetermined interval in the width direction and an automatic thickness adjusting mechanism that adjusts a gap between the slits with the heat bolt. . The heat bolt is preferably subjected to film formation by setting a profile according to the amount of pump 81 (preferably a high precision gear pump) according to a preset program. In order to precisely control the dope feed amount, the pump 80 is preferably a high-precision gear pump. In addition, a thickness measuring machine such as an infrared thickness gauge is provided in the film manufacturing facility 33, and feedback control to the automatic thickness adjusting mechanism is performed by an adjustment program based on the thickness profile and a detection result by the thickness measuring machine. Also good. It is preferable to use a casting die 81 that can adjust the slit interval of the tip lip to be ± 50 μm or less so that the difference in thickness at any two positions excluding both side ends of the film 62 as a product is within 1 μm.

More preferably, a cured film is formed at the lip end of the casting die 81. A method for forming the cured film is not particularly limited, and examples thereof include ceramic coating, hard chrome plating, and a nitriding method. In the case of using ceramics as the cured film, it is preferable to use a ceramic that can be ground, has a low porosity, is not brittle, has good corrosion resistance, and has no affinity or adhesion to the dope 24. Specific examples include tungsten carbide (WC), Al ₂ O ₃ , TiN, Cr ₂ O _{3 and the} like. Among them, WC is particularly preferable. The WC coating can be performed by a thermal spraying method.

  In order to prevent the dope 24 from locally drying and solidifying at the lip tip of the casting die 81, it is preferable to attach a solvent supply device (not shown) for supplying a solvent to the lip tip in the vicinity of the lip tip. The position where the solvent is supplied is preferably a peripheral portion of a three-phase contact line formed by both ends of the casting bead, both ends of the lip tip, and the outside air. The flow rate of the supplied solvent is preferably 0.1 mL / min to 1.0 mL / min for each side. Thereby, it is possible to prevent foreign matters, for example, solid components deposited from the dope 24 and those mixed in the casting bead from the outside from being mixed in the casting film 24a. In addition, as a pump which supplies a solvent, it is preferable to use a pulsation rate of 5% or less.

  The casting band 82 below the casting die 81 is stretched around the rotating rollers 85 and 86 and is continuously conveyed by the drive rotation of at least one of the rotating rollers.

  The width of the casting band 82 is not particularly limited, but it is preferable to use a casting band having a range of 1.1 to 2.0 times the casting width of the dope 24. Further, it is preferable that the length is 20 m to 200 m, the thickness is 0.5 mm to 2.5 mm, and the surface roughness is polished to be 0.05 μm or less.

  The material of the casting band 82 is not particularly limited, but is preferably stainless steel. Other materials include non-woven plastic films such as polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film, polycarbonate film and polyimide film. It is preferably a long product having chemical stability and heat resistance that can cope with the solvent to be used and the film forming temperature.

  The rotating rollers 85 and 86 are preferably provided with a heat transfer medium circulating device 87 for supplying the heat transfer medium to the rotating rollers 85 and 86 and controlling the surface temperature of the rollers. The surface temperature is set to a predetermined value. In this embodiment, a heat transfer medium flow path (not shown) is formed in the rotary rollers 85 and 86, and the heat transfer medium maintained at a predetermined temperature passes through the flow path, The temperature of the rotating rollers 85 and 86 is maintained at a predetermined value. The surface temperature of the casting band 82 is appropriately set according to the type of solvent, the type of solid component, the concentration of the dope 24, and the like.

A rotating drum (not shown) can be used as a support instead of the rotating rollers 85 and 86 and the casting band 82. In this case, it is preferable that the rotation can be performed with high accuracy so that the rotation speed unevenness is 0.2% or less. The rotating drum preferably has an average surface roughness of 0.01 μm or less, and preferably has a surface subjected to a hard chrome plating treatment or the like. Thereby, sufficient hardness and durability can be improved. In addition, it is preferable that the surface defects of the rotating drum, the casting band 82, and the rotating rollers 85 and 86 are suppressed to a minimum. Specifically, there is no pinhole of 30 μm or more, and the number of pinholes of 10 μm or more and less than 30 μm is 1 / m ² or less, and the number of pinholes of less than 10 μm is preferably ² / m ² or less.

  In the vicinity of the casting die 81, a decompression chamber 90 is preferably provided to control the pressure upstream of the casting bead formed from the casting die 81 to the casting band 82 in the traveling direction of the casting band 82. .

  In the vicinity of the band 53, in order to suppress the blow ducts 91 to 93 that blow wind to evaporate the solvent of the casting film 24a and the wind that disturbs the shape of the casting film 24a against the casting film 24a. The wind shielding plate 94 is provided.

  The casting chamber 63 is provided with a temperature control device 97 for keeping the internal temperature at a predetermined value, and a condenser (condenser) 98 for condensing and recovering the volatile organic solvent. A recovery device 99 for recovering the condensed and liquefied organic solvent is provided outside the casting chamber 63.

  A blower 102 is provided in the transition portion 101 downstream of the casting chamber 63. Further, the ear clip device 67 is provided with a crusher 103 for finely cutting the side edge scraps of the cut film 62.

  An adsorption recovery device 106 for adsorbing and recovering the solvent gas generated by evaporation from the film 62 is attached to the drying chamber 69. In FIG. 2, a cooling chamber 71 is provided downstream of the drying chamber 69, but a humidity control chamber (not shown) for adjusting the water content of the film 62 between the drying chamber 69 and the cooling chamber 71. May be provided. The static eliminator 72 is a forced static eliminator such as a static eliminator, and can adjust the charged voltage of the film 62 so as to be within a predetermined range (for example, −3 kV to +3 kV). The static eliminator 72 is illustrated as being disposed on the downstream side of the cooling chamber 71, but is not limited to this installation position. The knurling imparting roller pair 73 imparts knurling to both end portions of the film 62 by embossing. Inside the take-up chamber 76, a take-up roll 107 for taking up the film 62 and a press roller 108 for controlling the tension during the take-up are provided.

  Next, an example of a method for producing the film 62 using the film production equipment 33 as described above will be described below. The dope 24 is always made uniform by the rotation of the stirrer 78. Various additives can be appropriately mixed in the dope 24 during the stirring.

  The dope 24 is sent to the stock tank 32, and solid matter precipitation and aggregation are suppressed by stirring until it is cast. And the foreign material of a size more than a predetermined particle size and a gel-like foreign material are removed by filtration with the filtration apparatus 61. FIG.

The dope 24 is cast from the casting die 81 to the casting band 82. The relative position of the rotary roller 85 and the rotary roller 86 and / or the rotational speed of at least one of them is adjusted so that the tension generated in the casting band 82 is 10 ³ N / m × 10 ⁶ N / m. Further, the relative speed difference between the casting band 82 and the rotating rollers 85 and 86 is set to 0.01 m / min or less. It is preferable that the speed fluctuation of the casting band 82 is 0.5% or less, and the meandering in the width direction that occurs when the casting band 82 makes one round is 1.5 mm or less. In order to suppress this meandering, a detector (not shown) that detects the positions of both ends of the casting band 82 and a position adjuster (not shown) that adjusts the position of the casting band 82 according to the detection data from this detector. It is more preferable to provide feedback control of the position of the casting band 82. Further, it is preferable that the position fluctuation in the vertical direction associated with the rotation of the rotary roller 85 is within 200 μm for the casting band 82 immediately below the casting die 81. In addition, the temperature of the casting chamber 63 is preferably set to −10 ° C. to 57 ° C. by the temperature control device 97. The solvent evaporated in the casting chamber 63 is recovered by the recovery device 99 and then regenerated and reused as a solvent for dope production.

  A casting bead is formed from the casting die 81 to the casting band 82, and a casting film 24 a is formed on the casting band 82. In order to stabilize the state of the casting bead, the decompression chamber 90 is preferably controlled so that the upstream area of the bead has a predetermined pressure value. The reduced pressure value is preferably set to −2500 Pa to −10 Pa from the area on the downstream side with respect to the bead. It is preferable to attach a jacket (not shown) to the decompression chamber 90 so that the internal temperature is maintained at a predetermined temperature. In order to keep the shape of the casting bead desired, it is preferable to attach a suction device (not shown) to the edge portion of the casting die 81 to suck both sides of the bead. This edge suction air volume is 1 L / min. ~ 100 L / min. It is preferable that it is the range of these.

  After the casting film 24a has self-supporting properties, it is peeled off from the casting band 82 while being supported by the peeling roller 109. When peeled off, the film 62 contains a solvent. The film 62 is supported by a plurality of rollers and conveyed through the crossing portion 101, and then sent to the tenter 64. In the crossing portion 101, it is possible to apply a draw tension to the film 62 by making the rotational speed of the downstream roller faster than the rotational speed of the upstream roller. Moreover, in the crossover part 101, the drying air of desired temperature is sent to the film 62 vicinity from the air blower 102, or is directly sprayed on the film 62, and the drying of the film 62 is advanced. At this time, the temperature of the drying air is preferably 20 ° C to 250 ° C.

  The film 62 sent to the tenter 64 is dried while its both ends are held and conveyed by holding means such as a clip 64a. A pin may be used instead of the clip, and the film may be pierced and held by the pin. Moreover, it is preferable to divide the inside of the tenter 64 into different temperature zones and adjust the drying conditions appropriately for each of the zones. In the tenter 64, the film 62 can be stretched in the width direction. As described above, in at least one of the crossover portion 101 and the tenter 64, at least one direction of the casting direction and the width direction of the film 62 is 100.5% to 300% of the dimension before stretching. It is preferable to stretch so as to be.

  The film 62 is dried to a predetermined residual solvent amount by the tenter 64, and then both end portions thereof are cut and removed by the edge-cutting device 67. The separated both ends are sent to the crusher 103 by a cutter blower (not shown). By the crusher 103, the side end portion is crushed into chips. Since this chip is reused for dope manufacturing, the raw material can be effectively used. In addition, although it can also abbreviate | omit about the cutting process of this both-sides edge part, it is preferable to carry out in any one from the said casting process to the process of winding up the said film.

  On the other hand, the film 62 from which both side ends have been removed is sent to the drying chamber 69 and further dried. The internal temperature of the drying chamber 69 is not particularly limited, but is determined according to the heat resistance (glass transition point Tg, heat distortion temperature, melting point Tm, continuous use temperature, etc.) of the solid electrolyte, and is Tg or less. It is preferable. In the drying chamber 69, the film 62 is conveyed while being wound around a roller 68, and the solvent gas generated by evaporation is adsorbed and recovered by the adsorption recovery device 106. The air from which the solvent component has been removed is sent again as drying air into the drying chamber 69. In addition, it is more preferable that the drying chamber 69 is divided into a plurality of sections in order to change the blowing temperature. In addition, if a preliminary drying chamber (not shown) is provided between the ear opener 67 and the drying chamber 69 to preliminarily dry the film 62, the film temperature is prevented from rising sharply in the drying chamber 69. The shape change of the film 62 in the chamber 69 can be suppressed.

  The film 62 is cooled to approximately room temperature in the cooling chamber 71. In the case where a humidity control chamber is provided between the drying chamber 69 and the cooling chamber 71, it is preferable to blow air adjusted to a desired humidity and temperature onto the film 62 in the humidity control chamber. Thereby, it is possible to suppress the occurrence of curling of the film 62 and winding failure when winding.

  In the solution casting method, various steps such as a drying step and a side edge portion excision and removal step are performed before the film (solid electrolyte film) peeled off from the support is wound up. In each of these processes or between each process, the film is mainly supported or conveyed by a roller. These rollers include a driving roller and a non-driving roller, and the non-driving roller is mainly used for determining a film conveyance path and improving conveyance stability.

  The neutralizing device 72 sets the charged voltage while the film 62 is being conveyed to a predetermined value. The charged voltage after neutralization is preferably -3 kV to +3 kV. Further, the film 62 is preferably imparted with knurling by a knurling roller pair 73. In addition, it is preferable that the height of the unevenness | corrugation of the knurled location is 1 micrometer-200 micrometers.

  The film 62 is taken up by a take-up roll 107 in the take-up chamber 76. It is preferable to wind the film while applying a desired tension to the film 62 by the press roller. It is more preferable to gradually change the tension from the start to the end of winding, thereby preventing excessive winding in the film roll. The width of the film 62 to be wound is preferably 100 mm or more. The present invention is also applied to the production of a thin film having a film thickness of 5 μm or more and 300 μm or less.

  In the present invention, when casting the dope 24, a method in which two or more kinds of dopes are simultaneously laminated co-cast or sequentially laminated co-cast may be used. When performing simultaneous lamination and co-casting, a casting die to which a feed block is attached may be used, or a multi-manifold casting die may be used. As for the film which consists of a multilayer by co-casting, it is preferable that any one of the two layers exposed on the surface is 0.5% to 30% of the total thickness of the film. Further, in the case of simultaneous lamination co-casting, the concentration of each dope is set in advance so that when the dope is cast from the die slit to the support, the high-viscosity dope is wrapped and cast by the low-viscosity dope. It is preferable to adjust. In the case of simultaneous lamination and co-casting, the bead formed from the die slit to the support is in contact with the outside world, that is, the exposed dope has a larger proportion of the poor solvent than the internal dope. It is preferable.

  In place of the above-described method for forming a solid electrolyte into a film, a film in which the solid electrolyte enters the pores is manufactured by holding the solid electrolyte in the pores of a so-called porous substrate in which a plurality of pores are formed. However, a solid electrolyte film different from the above embodiment can be manufactured. As a method for producing such a solid electrolyte film, a method in which a sol-gel reaction solution containing a solid electrolyte is applied onto a porous substrate and the solid electrolyte is put into pores, and the porous substrate includes a solid electrolyte. There is a method of immersing in a sol-gel reaction solution to fill the solid electrolyte in the pores. Preferable examples of the porous substrate include porous polypropylene, porous polytetrafluoroethylene, porous cross-linked heat-resistant polyethylene, and porous polyimide. Moreover, a solid electrolyte film can also be formed by processing a solid electrolyte into a fiber shape, filling voids in the fiber with other polymer compounds, etc., and forming the film using the fiber. In this case, examples of the other polymer compound for filling the void include the substances mentioned as additives in the present specification.

  The solid electrolyte film of the present invention can be suitably used as a proton conductive membrane for a fuel cell, in particular, a direct methanol fuel cell, and also used as a solid electrolyte film sandwiched between two electrodes of a fuel cell. Can do. Furthermore, as electrolytes, display elements, electrochemical sensors, signal transmission media, capacitors, electrodialysis, electrolytic membranes for electrolysis, gel actuators, salt electrolytic membranes, proton exchange resins in various batteries (redox flow batteries, lithium batteries, etc.) The solid electrolyte film of the present invention can be used.

(Fuel cell)
Hereinafter, an example in which the solid electrolyte film is used for an electrode membrane assembly (hereinafter referred to as MEA) and an example in which the electrode membrane assembly is used for a fuel cell will be described. However, the modes of the MEA and the fuel cell shown here are examples of the present invention, and the present invention is not limited thereto. FIG. 3 is a schematic cross-sectional view of the MEA. The MEA 131 includes a film 62 and an anode electrode 132 and a cathode electrode 133 that are opposed to each other with the film 62 interposed therebetween.

  The anode electrode 132 has a porous conductive sheet 132 a and a catalyst layer 132 b in contact with the film 62, and the cathode electrode 133 has a porous conductive sheet 133 a and a catalyst layer 133 b in contact with the film 62. Examples of the porous conductive sheets 132a and 133a include carbon paper. The catalyst layers 132b and 133b are made of a dispersion in which carbon particles carrying a catalyst metal such as platinum particles are dispersed in a proton conductive material. Examples of the carbon particles include ketjen black, acetylene black, and carbon nanotube. Examples of the proton conductive material include Nafion.

As the manufacturing method of the MEA 131, the following four methods are preferable.
(1) Proton conductive material coating method: A catalyst paste (ink) containing active metal-carrying carbon, a ptron conductive material, and a solvent is directly applied to both surfaces of the film 62, and the porous conductive sheets 132a and 133a are applied to the (heat) coating layer. A MEA having a five-layer structure is manufactured by pressure bonding.
(2) Porous conductive sheet coating method: After a liquid containing the material of the catalyst layers 132b and 133b, for example, a catalyst paste, is applied to the surfaces of the porous conductive sheets 132a and 133a to form the catalyst layers 132b and 133b. The film 62 is pressure-bonded to produce a MEA 131 having a five-layer structure.
(3) Decal method: After a catalyst paste is applied on PTFE to form catalyst layers 132b and 133b, only the catalyst layers 132b and 133b are formed on the film 62 to form a three-layer structure. The sheets 132a and 133a are pressure-bonded to produce a MEA 131 having a five-layer structure.
(4) Post-catalyst loading method: An ink in which a platinum unsupported carbon material is mixed with a proton conductive material is applied and formed on the film 62, the porous conductive sheets 132a, 133a or PTFE, and then the film is applied to a liquid containing platinum ions. 62 is impregnated, and platinum particles are reduced and deposited in the film to form the catalyst layers 132b and 133b. After the formation of the catalyst layers 132b and 133b, the MEA 131 is produced by the above methods (1) to (3).

  However, the method of making the MEA is not limited to the above method, and various known methods can be applied. For example, in addition to the above methods (1) to (4), there are the following methods. A coating solution containing the materials of the catalyst layers 132b and 133b is prepared in advance, and this coating solution is applied to a support and dried. The support on which the catalyst layers 132b and 133b are formed is pressure-bonded on the both sides of the film 62 so that the catalyst layers 132b and 133b are in contact with the film 62, respectively. And after peeling a support body, the film 62 in which the catalyst layers 132b and 133b were formed in both surfaces is pinched | interposed with the porous conductive sheets 132a and 133a. And MEA can be manufactured by closely contacting the porous conductive sheets 132a and 133a and the catalyst layers 132b and 133b.

  FIG. 4 is a schematic view of a fuel cell. The fuel cell 141 includes an MEA 131, a pair of separators 142 and 143 that sandwich the MEA 131, a current collector 146 made of a stainless net attached to the separators 142 and 143, and a packing 147. An anode pole side opening 151 is provided in the anode pole side separator 142, and a cathode pole side opening 152 is provided in the cathode pole side separator 143. Gas fuel such as hydrogen and alcohols (such as methanol) or liquid fuel such as an alcohol aqueous solution is supplied from the anode electrode side opening 151, and oxidant gas such as oxygen gas and air is supplied from the cathode electrode side opening 152. Is supplied.

  A catalyst in which active metal particles such as platinum are supported on a carbon material is used for the anode electrode 132 and the cathode electrode 133. Commonly used active metal particle sizes are in the range of 2 to 10 nm. However, the smaller the particle size, the greater the surface area per unit weight, which increases the activity and is advantageous. However, if it is too small, it is difficult to disperse without agglomeration, so about 2 nm is said to be the small limit. .

  The active polarization in the hydrogen-oxygen fuel cell is larger in the cathode electrode, that is, the air electrode than in the anode electrode, that is, the hydrogen electrode. This is because the rate of the cathode electrode reaction, that is, the oxygen reduction reaction, is slower than that of the anode electrode. For the purpose of improving the activity of the oxygen electrode, various platinum-based binary metals such as Pt—Cr, Pt—Ni, Pt—Co, Pt—Cu, and Pt—Fe can be used. In a direct methanol fuel cell using a methanol aqueous solution as the anode fuel, in order to suppress catalyst poisoning by CO generated during the oxidation process of methanol, Pt—Ru, Pt—Fe, Pt—Ni, Pt—Co, and Pt—Mo are used. Pt-Ru-Mo, Pt-Ru-W, Pt-Ru-Co, Pt-Ru-Fe, Pt-Ru-Ni, Pt-Ru-Cu, Pt-Ru-Sn, etc. A platinum group ternary metal such as Pt—Ru—Au can be used. As the carbon material for supporting the active metal, acetylene black, Vulcan XC-72, ketjen black, carbon nanohorn (CNH), and carbon nanotube (CNT) are preferably used.

The catalyst layers 132b and 133b are generated by (1) transporting the fuel to the active metal, (2) providing a field for the oxidation (anode electrode) and reduction (cathode electrode) reaction of the fuel, and (3) oxidation / reduction. And (4) transports protons generated by the reaction to the solid electrolyte, that is, the film 62. For (1), the catalyst layers 132b and 133b are made porous so that liquid and gaseous fuel can permeate deeply. For (2), the active metal catalyst supported on the carbon material is responsible, and (3) is also responsible for the carbon material. In order to fulfill the function (4), a proton conductive material is mixed in the catalyst layers 132b and 133b. The proton conductive material of the catalyst layer is not limited as long as it is a solid having a proton donating group, but a polymer compound having an acid residue used for the film 62, for example, perfluorosulfonic acid represented by Nafion. A sulfonated product of a heat-resistant aromatic polymer such as a side chain phosphate group poly (meth) acrylate, a sulfonated polyetheretherketone, or a sulfonated polybenzimidazole is preferably used. When the solid electrolyte used as the material of the film 62 is used for the catalyst layers 132b and 133b, the catalyst layers 132b and 133b and the film 62 are the same type of material, so that the electrochemical adhesion between the solid electrolyte and the catalyst layer is increased. This is more advantageous in terms of ion conduction. It is suitable from a viewpoint of battery output and economical efficiency to make the usage-amount of an active metal into the range of 0.03-10 mg / cm < ² >. The amount of the carbon material supporting the active metal is preferably 1 to 10 times the weight of the active metal. The amount of the proton conductive material is preferably 0.1 to 0.7 times the weight of the active metal-carrying carbon.

  The catalyst layers 132b and 133b are also referred to as an electrode base material, a permeable layer, or a backing material, and play a role of preventing current collection and deterioration of gas permeation and accumulation of water. Usually, carbon paper or carbon cloth can be used, and polytetrafluoroethylene (PTFE) treated for water repellency can be used.

MEA is incorporated into a battery, preferably having an area resistance value of 3Omucm ² below by the AC impedance method in a state filled with fuel, more preferably those of 1 .OMEGA.cm ² or less, and most preferably those 0.5Omucm ² below. The area resistance value is obtained from the product of the actually measured resistance value and the area of the sample.

  What can be used as a fuel of a fuel cell will be described. Examples of the anode fuel include hydrogen, alcohols (such as methanol, isopropanol, and ethylene glycol), ethers (such as dimethyl ether, dimethoxymethane, and trimethoxymethane), formic acid, borohydride complex, and ascorbic acid. Examples of the cathode fuel include oxygen (including oxygen in the atmosphere) and hydrogen peroxide.

In the direct methanol fuel cell, a methanol aqueous solution having a methanol concentration of 3 to 64% by weight is used as the anode fuel. According to the anode reaction formula (CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ ), 1 mol of water is required for 1 mol of methanol, and the methanol concentration at this time corresponds to 64% by weight. The higher the methanol concentration, there is an advantage that the weight and volume of the battery including the fuel tank with the same energy capacity can be reduced. However, the higher the methanol concentration, the more so-called crossover phenomenon that methanol permeates the solid electrolyte and reacts with oxygen on the cathode side to lower the voltage, and the output tends to decrease. Therefore, the optimum concentration is determined by the methanol permeability of the solid electrolyte used. The cathode reaction formula of the direct methanol fuel cell is (3/2) O ₂ + 6H ⁺ + 6e ⁻ → H ₂ O, and oxygen (usually oxygen in the air) is used as the fuel.

  As a method of supplying the anode fuel and the cathode fuel to the respective catalyst layers 132b and 133b, (1) a method of forcibly feeding using an auxiliary device such as a pump (active type), and (2) an auxiliary device There are two methods that are not used, for example, a passive type in which the fuel is exposed to the atmosphere by exposing the catalyst layer to the atmosphere due to capillary action or natural fall when the fuel is a liquid, and ( It is also possible to combine 1) and (2). (1) has the advantage that by extracting the water produced on the cathode side, high-concentration methanol can be used as the fuel, and high output can be achieved by air supply, but a fuel supply system is provided. Therefore, there is a drawback that miniaturization is difficult. Although (2) has the advantage that it can be downsized, it has a drawback that the fuel supply is likely to be rate-limiting and it is difficult to produce a high output.

  Since the single cell voltage of the fuel cell is generally 1 V or less, the single cells are used by stacking in series according to the required voltage of the load. As the stacking method, “planar stacking” in which single cells are arranged on a plane and “bipolar stacking” in which single cells are stacked via separators having fuel flow paths formed on both sides thereof are used. The former is suitable for a small fuel cell because the cathode electrode (air electrode) comes out on the surface, so that air can be easily taken in and can be made thin. In addition to this, a method of applying MEMS technology, performing fine processing on a silicon wafer, and stacking has been proposed.

  Fuel cells are considered for various uses such as for automobiles, homes, and portable devices.In particular, direct methanol fuel cells are advantageous in that they can be reduced in size and weight and do not require charging. It is expected to be used as an energy source for various portable devices and portable devices. For example, mobile devices that can be preferably applied include mobile phones, mobile laptop computers, electronic still cameras, PDAs, video cameras, portable game machines, mobile servers, wearable personal computers, mobile displays, and the like. Examples of portable devices that can be preferably applied include portable generators, outdoor lighting devices, flashlights, and electric (assist) bicycles. It can also be preferably used as a power source for industrial or household robots or other toys. Furthermore, it is also useful as a power source for charging secondary batteries mounted on these devices.

  Next, examples of the present invention will be described. In each of the following examples, details will be described in Example 1, and only the conditions different from Example 1 will be described for Examples 2 to 8. Examples 1 to 3 and Examples 7 and 8 are examples of the embodiment of the present invention, and Examples 4 to 6 are comparative experiments with respect to Examples 1 to 3.

[Dope production]
(1) Raw material preparation The raw material A was flash-concentrated with the flash device 26. The concentrate was then dried with a paddle dryer. The paddle dryer was dried for 100 minutes while sending 120 ° C wind to the concentrate. The water content after drying was 0.5% by weight. This dried product was used as a solid electrolyte. The dried product was supplied to the hopper 13 by air blowing so as not to absorb moisture from the outside air again. Perfluorohexane as a solvent was purified by distillation to a water content of 0.2% by weight. The raw material A is 20% Nafion (registered trademark) Dispersion Solution DE2020 (manufactured by DuPont, USA).

(2) Raw material A after preparation and drying of dope: 100 parts by weight / solvent: 400 parts by weight of perfluorohexane A dope 24 was prepared using a dope production line 10 shown in FIG. The purified solvent was sent to a 200 L stainless steel mixing tank 17 equipped with a stirring blade. In addition, the mixing | blending of the raw material A and solvent after drying as a solid electrolyte is as above-mentioned. Next, the solid electrolyte was gradually put into the mixing tank 17 from the hopper 13. At first, the dissolver type eccentric stirrer 52 is stirred at a peripheral speed of 5 m / sec and a stirrer 48 having an anchor blade on the rotating shaft is set at a peripheral speed of 1 m / sec. I let you. Then, the peripheral speed of the anchor blade of the stirrer 48 was set to 0.5 m / sec, and the mixture was further stirred for 100 minutes to swell the solid electrolyte to obtain a mixed liquid 16 as a swelling liquid. Until the end of swelling, the inside of the mixing tank 17 was pressurized with nitrogen gas so as to be 0.12 MPa. Inside the pressurized mixing tank 17, the oxygen concentration was less than 2 vol%, and a state with no explosion problem was maintained.

(3) Dissolution / Filtration The mixed liquid 16 in a swollen state was sent from the mixing tank 17 to the heating device 18 which is a jacketed pipe using a pump 41. In the heating device 18, the mixed liquid 16 was heated to 90 ° C. under a pressure of 2 MPa, and the solid dispersion was completely dissolved. The heating time in the heating device 18 was 30 minutes. The mixed solution 16 that passed through the heating device 18 was cooled to 30 ° C. by the temperature regulator 21, and then passed through a filtration device 22 equipped with a filter having a nominal pore diameter of 8 μm to obtain a dope 24. Under the present circumstances, the primary side pressure in the filtration apparatus 22 was 1.5 MPa, and the secondary side pressure was 1.2 MPa. Filters, housings, and piping exposed to high temperatures were made of Hastelloy (trade name) alloy having excellent corrosion resistance, and they were equipped with a jacket for circulating a heat transfer medium for heat retention and heating.

(4) Filtration / Defoaming The dope 24 was simply transferred to the tank body (not shown) of the flash device 26 without being concentrated. The tank body was provided with a stirrer (not shown) having an anchor blade on the stirring shaft, and the dope 24 was stirred and defoamed with a stirrer that was rotated at a peripheral speed of 0.5 m / sec. The average residence time of the dope 24 in the tank body was 50 minutes. Next, bubble removal was continued by irradiating the dope 24 with weak ultrasonic waves. Then, the filtration apparatus 27 was allowed to pass in the state pressurized to 1.5 MPa by the pump 42. The filter device 27 is provided with two filters, and the upstream side and the downstream side are the same filters. This filter is a sintered fiber metal filter having a nominal pore diameter of 10 μm. Respective primary pressures were 1.5 MPa and 1.2 MPa, and secondary pressures were 1.0 MPa and 0.8 MPa. The temperature of the dope 24 after filtration was adjusted to 30 ° C., and the dope 24 was sent to a 500 L stainless steel stock tank 32 and stored. The stock tank 32 has a stirrer 78 having an anchor blade on the central axis, and the dope 24 was constantly stirred at a peripheral speed of 0.3 m / sec. The concentration of the dope 24 obtained here is 23% by weight.

[Manufacture of solid electrolyte film 62]
Casting from a casting die 81 to a casting band 82 running on the dope A to form a casting film, blown dry air of 30 to 50 ° C. through the air ducts 91 to 93, and the solid content of the raw material A, that is, the solid electrolyte The cast film 24a was dried until the solvent content was 30% by weight with respect to the weight. When the casting membrane 24a had self-supporting property, the casting membrane was peeled off as a film 62 from the casting band 82. The film 62 was sent to the tenter 64 and conveyed inside the tenter 64 while being gripped at both ends by the clips 64a. In the tenter 64, the film 62 was dried with a drying air at 50 ° C. until the solvent content was 15% by weight with respect to the solid content. The film 62 detached from the clip 64 a at the outlet of the tenter 64 was cut and removed at both side ends gripped by the clip 64 a by an ear clip device 67 provided downstream of the tenter 64. The film 62 from which both end portions were removed was sent to the drying chamber 69 and dried at 50 to 70 ° C. while being conveyed by a plurality of rollers 68. Then, a solid electrolyte film 62 having a solvent content of less than 3% was obtained.

  The obtained film 62 was subjected to the following evaluations. The evaluation results are shown in Table 1. The numbers of the evaluation items in Table 1 correspond to the numbers given to the following evaluation items.

1. Thickness The thickness of the film 62 was continuously measured using an electronic micrometer manufactured by Anritsu Electric Co., Ltd. at a speed of 600 mm / min. Data obtained by the measurement was recorded on the chart paper at a scale of 1/20 and a chart speed of 30 mm / min. And after measuring with respect to a data curve with a ruler, the average value of thickness and the dispersion | variation in the thickness with respect to this average value were calculated | required based on the measured value. In Table 1, (a) represents the average thickness (unit: μm), and (b) represents the thickness variation (unit: μm) relative to (a).

2. Water content of the dope 24 The dope 24 was sampled by 3 cc, and the water weight was measured by the Karl Fischer method. Both the moisture measuring device and the sample drying apparatus used were manufactured by Mitsubishi Chemical Corporation, the former being model CA-03 and the latter being model VA-05. Then, the obtained water content was divided by the sampling weight to calculate the water content.

3. Number of Defects The light was applied to the area of the entire width x 1 m of the film 62 and reflected, and the defect part such as deformation was visually detected by the reflected light. Then, the defect location detected visually was confirmed with the polarizing microscope, and the number of the defect locations per 1 mm < ² > was counted. Note that deformations made after sampling, such as scratches, were excluded from the count.

4). Ion conductivity measurement About the obtained solid electrolyte film 62, ten measurement locations were selected every 1 m along the longitudinal direction. Ten of them were punched out as a circular sample having a diameter of 13 mm. Each sample was sandwiched between two stainless steel plates, and ion conductivity was measured by an AC impedance method using Solartron 1470 and 1255B. The measurement was performed under the conditions of 80 ° C. and relative humidity of 95%. As shown in Table 1, the ionic conductivity is shown as an AC impedance value (unit: S / cm).

5. Output density of fuel cell 141 A fuel cell 141 was produced using the film 62, and the output of the fuel cell 141 was measured. The production method of the fuel cell 141 and the measurement method of the power density are as follows.

(1) Preparation of catalyst sheet A used as catalyst layers 132b and 133b 2 g of platinum-supporting carbon and 15 g of a solid electrolyte (5% DMF solution) were mixed and dispersed for 30 minutes with an ultrasonic disperser. The average particle size of the dispersion was about 500 nm. The obtained dispersion was applied onto a carbon paper having a thickness of 350 μm and dried, and then the carbon paper was punched into a circle having a diameter of 9 mm to prepare a catalyst sheet A. The platinum-supporting carbon was obtained by supporting 50 wt% platinum on Vulcan XC72, and the solid electrolyte was the same as that for manufacturing the film 62.

(2) Production of MEA 131 Catalyst sheet A was laminated on both surfaces of solid electrolyte film 62 so that the coating film was in contact with film 62, and thermocompression bonded at 80 ° C. and 3 MPa for 2 minutes to produce MEA.

(3) Output Density of Fuel Cell 141 The MEA obtained in (2) was set in the fuel cell shown in FIG. 3, and a 15 wt% aqueous methanol solution was injected into the opening 151 on the anode electrode side. At this time, the opening 152 on the cathode electrode side was in contact with the atmosphere. The anode electrode 132 and the cathode electrode 133 were connected by a multichannel battery evaluation system (Solartron 1470), and the output density (unit: W / cm ² ) was measured.

[Dope production]
1. Preparation of Raw Material A sulfonated polyacrylonitrile butadiene styrene having a sulfonation degree of 35% was used as a solid electrolyte, and this was used as a raw material B. First, the raw material B was produced by the following synthesis method.
(1) Synthesis of 4- (4- (4-pentylcyclohexyl) phenoxymethyl) styrene After reacting substances having the following composition at 100 ° C. for 7 hours, the resulting reaction solution was cooled to room temperature, Water was added for crystallization. After filtering the crystallization solution, the obtained filtrate was washed with an aqueous solution of water / acetonitrile = 1/1 and air-dried to obtain 4- (4- (4-pentylcyclohexyl) phenoxymethyl) styrene.
-14 parts by weight of 4- (4-pentylcyclohexyl) phenol-9 parts by weight of 4-chloromethylstyrene-11 parts by weight of potassium carbonate-66 parts by weight of N, N-dimethylformamide

2. Synthesis of Graft Copolymer A mixture having the following composition was heated to 60 ° C.
-Polybutadiene latex 100 parts-Potassium rosinate 0.83 parts-Dextrose 0.50 parts by weight-Sodium pyrophosphate 0.17 parts by weight-Ferrous sulfate 0.08 parts by weight-Water 250 parts by weight

Thereafter, a mixture having the following composition was added dropwise over 60 minutes to the above mixture to carry out a polymerization reaction.
Acrylonitrile 21 parts by weight 4- (4-4-pentylcyclohexyl) phenoxymethyl) styrene 62 parts by weight t-dodecylthiol 0.5 parts by weight Cumene hydroperoxide 3.0 parts by weight

  After completion of the dropwise addition, 0.2 parts by weight of cumene hydroperoxide was added thereto, followed by cooling for 1 hour to obtain a latex. The obtained latex was put in 60 ° C. and 1% sulfuric acid, and heated to 90 ° C. for coagulation. This was thoroughly washed with water and dried to obtain a graft copolymer.

3. Synthesis of raw material B by sulfonation of graft copolymer 100 parts by weight of the graft copolymer obtained in 2 above was dissolved in 1300 parts by weight of methylene chloride, and the resulting solution was kept at 0 ° C. or lower. 13 parts by weight of concentrated sulfuric acid was slowly added. This was stirred for 6 hours to cause precipitation. After removing the solvent, the precipitate was dried to obtain raw material B, that is, sulfonated polyacrylonitrile butadiene styrene as a solid electrolyte. The introduction rate of sulfonic acid groups by titration was 35%.

  The raw material B was dried with a paddle dryer as the drying device 55. The drying conditions in the paddle dryer were the same as in Example 1, and the moisture content after drying was 0.5% by weight. This dried product was used as a solid electrolyte. In the same manner as in Example 1, N, N-dimethylformamide as a solvent was purified by distillation so that the water content was 0.2% by weight.

The dried raw material B and the solvent were mixed in the following composition, and the raw material B was dissolved in the solvent to produce a 23 wt% solid electrolyte dope 24. This dope 24 is referred to as dope B in the following description.
-Raw material B; 100 parts by weight-Solvent: 400 parts by weight of N, N-dimethylformamide

[Manufacture of solid electrolyte film 62]
The mixed liquid 16 was heated to 120 ° C. under 2 MPa pressure in the heating device 18, and the solid dispersion was completely dissolved. The temperature of the wind from the air ducts 91-93 was 80-120 degreeC. The temperature of the drying air in the tenter 64 was 140 ° C. The film 62 from which the side edge portion was removed by the edge cutting device 67 was dried at a temperature of 140 to 160 ° C. in the drying chamber 62 to obtain a solid electrolyte film 62 having a solvent content of less than 3%. The evaluation results on the obtained film 62 are shown in Table 1.

[Dope production]
(1) Raw material preparation A sulfopropylated polyethersulfone having a sulfonation degree of 35% was used as a solid electrolyte, and this was used as a raw material C. First, the raw material C was synthesized based on the synthesis method described in JP-A No. 2002-110174.

  The raw material C was dried with a paddle dryer as the drying device 55. The drying conditions in the paddle dryer were the same as in Example 1, and the moisture content after drying was 0.5% by weight. This dried product was used as a solid electrolyte. In the same manner as in Example 1, N-methylpyrrolidone as a solvent was purified by distillation so that the water content was 0.2% by weight.

The dried raw material C and the solvent were mixed in the following composition, and the raw material C was dissolved in the solvent to produce a 20 wt% solid electrolyte dope 24. This dope 24 is referred to as dope C in the following description.
-Raw material C; 100 parts by weight-Solvent: 400 parts by weight of N-methylpyrrolidone Raw material C and the solvent were mixed in the following composition, and the raw material C was dissolved in the solvent to produce 20 wt% of the solid electrolyte dope 24. This dope 24 is referred to as dope C in the following description.

[Manufacture of solid electrolyte film 62]
The temperature of the wind from the air ducts 91-93 was 80-140 degreeC. The temperature of the drying air in the tenter 64 was 160 ° C. The film 62 from which the side edge portion was removed by the edge cutting device 67 was dried in a drying chamber 62 at a temperature of 160 to 180 ° C., thereby obtaining a solid electrolyte film 62 having a solvent content of less than 3%. The evaluation results on the obtained film 62 are shown in Table 1.

  The drying of the solid electrolyte and the purification of the solvent were not performed, and only one filter in the filtration device 27 was used. Other conditions are the same as those in the first embodiment. The evaluation results of the obtained film are shown in Table 1.

  The drying of the solid electrolyte and the purification of the solvent were not performed, and only one filter in the filtration device 27 was used. Other conditions are the same as those in Example 2. The evaluation results of the obtained film are shown in Table 1.

  The drying of the solid electrolyte and the purification of the solvent were not performed, and only one filter in the filtration device 27 was used. Other conditions are the same as those in Example 3. The evaluation results of the obtained film are shown in Table 1.

The compound shown in Chemical formula 3 was used as a solid electrolyte. However, protonation for obtaining the compound of Chemical Formula 3, that is, acid treatment was carried out in the film production process as follows, not before the dope production. An unprotonated product of Chemical Formula 3, that is, a solid electrolyte precursor, is used as a raw material D. Moreover, this raw material D was dissolved in a solvent to obtain a dope for casting. The method for making this dope is the same as the method for making the dope 24 in the first embodiment. The solvent is a mixture of the solvent component 1 and the solvent component 2. The solvent component 1 is a good solvent for the raw material D, and the solvent component 2 is a poor solvent for the raw material D. In Example 7, X in Chemical Formula 3 is Na, Y is SO ₂ , Z is Chemical Formula 4 (I), n is 0.33, m is 0.67, number average molecular weight Mn is 61000, and weight average molecular weight. Mw is 159000.
-Raw material D; 100 parts by weight-Solvent component 1; 256 parts by weight of dimethyl sulfoxide-Solvent component 2; 171 parts by weight of methanol

  Since the dope cast and peeled off from the casting band 82 is made of the raw material D, it will be referred to as a precursor film. The precursor film from which both side ends were removed by the edge-cutting device 67 through the same conditions as in Example 1 was protonated by acid treatment and then subjected to a washing step. The acid treatment is a step of bringing the precursor film into contact with an acid aqueous solution. By this acid treatment, the structure of the precursor becomes a structure represented by the general formula of Chemical Formula 3, that is, a solid electrolyte. The contact was performed by a method in which an aqueous acid solution was continuously supplied to a liquid tank and a film made of a solid electrolyte was immersed in this aqueous solution. Washing after the acid treatment was carried out with water. The film 62 after the cleaning process was sent to the drying chamber 69. The evaluation results for the obtained film 62 are shown in Table 1.

The compound shown in Chemical formula 3 and different from Example 7 was used as the solid electrolyte. However, protonation for obtaining the compound of Chemical Formula 3 was carried out in the film production process, not before the dope production, as in Example 7. A precursor used as a dope component is referred to as a raw material E. The solvent is a mixture of solvent component 1 and solvent component 2 as shown below. The solvent component 1 is a good solvent for the raw material E, and the solvent component 2 is a poor solvent for the raw material E. Further, in Example 8, X in Chemical Formula 3 is Na, Y is SO ₂ , Z is Chemical Formulas (I) and (II), n is 0.33, m is 0.67, and the number average molecular weight Mn is 68,000 and the weight average molecular weight Mw are 200000. In Chemical Formula 4, (I) is 0.7 mol% and (II) is 0.3 mol%. The other conditions are the same as in Example 7.
-Raw material E; 100 parts by weight-Solvent component 1; 200 parts by weight of dimethyl sulfoxide-Solvent component 2; 135 parts by weight of methanol

  From the results of the above examples, according to the present invention, it is possible to produce a dope suitable for continuously forming a solid electrolyte into a film, as well as having a constant quality and excellent ion conductivity and durability. It turns out that a solid electrolyte film can be manufactured continuously. And it turns out that the obtained solid electrolyte film can be used conveniently as a solid electrolyte layer of a fuel cell.

It is the schematic of dope manufacturing equipment. It is the schematic of a film manufacturing equipment. It is sectional drawing of an electrode membrane composite. It is sectional drawing of a fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dope production equipment 24 Dope 18 Heating device 22, 27 Filtration device 26 Flash device 33 Film production equipment 55 Drying device 56 Purification device 62 Solid electrolyte film 69 Drying chamber 131 Electrode membrane composite (MEA)
132 Anode electrode 133 Cathode electrode 141 Fuel cell 146 Current collector

Claims (21)

A drying step of drying the solid electrolyte;
A purification step of purifying the solvent;
A mixing step in which the solid electrolyte that has undergone the drying step and the solvent that has undergone the purification step are mixed to form a mixed solution;
A dissolution step of dissolving the solid electrolyte in the solvent and using the mixed solution as a solution;
Filtration step to remove foreign matters by filtering the solution, and to be a solid electrolyte dope to be used for solution casting,
A method for producing a solid electrolyte dope comprising:   The method for producing a solid electrolyte dope according to claim 1, further comprising a concentration step of concentrating the solution to increase the concentration of the solid electrolyte.   The method for producing a solid electrolyte dope according to claim 1 or 2, wherein in the drying step, the solid electrolyte is dried by heating to 100 ° C or higher.   The method for producing a solid electrolyte dope according to any one of claims 1 to 3, wherein the purification step includes a moisture removal step of removing moisture previously contained in the solvent from the solvent.   5. The method for producing a solid electrolyte dope according to claim 4, wherein the moisture content of the solvent is 2% by weight or less in the moisture removing step.   The method for producing a solid electrolyte dope according to any one of claims 2 to 5, wherein, in the concentration step, the water content of the solution is less than 2% by weight.   The method for producing a solid electrolyte dope according to any one of claims 1 to 6, wherein in the filtration step, the solution is filtered by a filtering means having a pore diameter of less than 20 µm. A mixing step of mixing a pre-dried solid electrolyte and a pre-purified solvent to form a mixed solution;
A dissolution step of dissolving the solid electrolyte in the mixed solution in the solvent to form a solution;
Filtration step of removing foreign matter by filtering the solution to form a solid electrolyte dope,
Casting on the support that runs the solid electrolyte dope to form a casting film, and casting the casting film as a film; and
A film drying step of drying the film;
A method for producing a solid electrolyte film, comprising:   The method for producing a solid electrolyte film according to claim 8, further comprising a concentration step of concentrating the solution to increase the concentration of the solid electrolyte.   The method for producing a solid electrolyte film according to claim 8 or 9, wherein the drying of the solid electrolyte is performed by heating at 100 ° C or higher.   The method for producing a solid electrolyte film according to any one of claims 8 to 10, wherein the water content in the solvent is 2% by weight or less by the purification of the solvent.   The method for producing a solid electrolyte film according to any one of claims 9 to 11, wherein in the concentration step, concentration is performed so that a water content in the solution is less than 2% by weight.   13. The solid electrolyte according to claim 8, wherein a compound that is a poor solvent for the solid electrolyte is the first solvent, and a compound that is a good solvent for the solid electrolyte is the second solvent. A method for producing a film.   14. The method for producing a solid electrolyte film according to claim 13, wherein the weight of the first solvent relative to the sum of the weights of the first and second solvents is 10% or more and less than 100%.   The method for producing a solid electrolyte film according to claim 13 or 14, wherein the second solvent contains dimethyl sulfoxide, and the first solvent contains an alcohol having 1 to 5 carbon atoms.   16. The method for producing a solid electrolyte film according to claim 8, wherein the solid electrolyte is a hydrocarbon polymer.   The method for producing a solid electrolyte film according to claim 16, wherein the hydrocarbon polymer is an aromatic polymer having a sulfonic acid group. 18. The method for producing a solid electrolyte film according to claim 17, wherein the aromatic polymer is a copolymer composed of structural units represented by general formulas (I) to (III) of Chemical Formula 1.

(However, X is H, Y is SO ₂ , Z is the structure shown in Chemical Formula (I) or (II), and n and m satisfy 0.1 ≦ n / (m + n) ≦ 0.5. .)

  A solid electrolyte film produced by the production method according to claim 8. The solid electrolyte film according to claim 19,
An anode electrode that is provided in close contact with one surface of the solid electrolyte film and generates protons from a hydrogen-containing substance supplied from the outside;
A cathode electrode that is provided in close contact with the other surface of the solid electrolyte film and synthesizes water from the proton that has passed through the solid electrolyte film and a gas supplied from the outside;
An electrode membrane composite comprising: The electrode membrane composite according to claim 20,
A current collector that is provided in contact with the electrode of the electrode membrane composite, and transfers electrons between the anode electrode and the cathode electrode and the outside;
A fuel cell comprising:

Images