JP2006310068A - Solid electrolyte, membrane and electrode assembly, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid electrolyte having high ion conductivity. <P>SOLUTION: The solid electrolyte contains a high polymer compound which has a group with two or more sulfonic acid groups, in a principal chain and/or a side chain. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid electrolyte, an electrode membrane assembly, and a fuel cell.

  Recently, lithium ion batteries can be used as power source for portable devices, fuel cells have been actively studied, lithium ion conducting material, also actively studied solid electrolyte such as proton-conductive material is made which is a member.

Further, it is preferable that the power source is small as long as it has the same output. In particular, fuel cells are being actively studied because of their features such as quietness and cleanness of exhaust gas with respect to internal combustion engines such as engines, and the possibility of high energy efficiency exceeding that of internal combustion engines.
In general, a perfluorocarbon sulfonic acid membrane represented by Nafion (registered trademark) is used as a proton conductive material, but the proton conductivity is not sufficient yet, and the sulfonic acid group in the polymer structure is increased in order to increase the proton conductivity. Increasing the amount causes a decrease in mechanical strength and solubilization in an aqueous solvent. Moreover, since it softens and proton conductivity falls in a high temperature state (for example, 100 degreeC or more), there exists a problem in use in a high temperature range (for example, 120-140 degreeC or more). Furthermore, the monomer used is relatively expensive, and the manufacturing method is complicated, resulting in an increase in manufacturing cost.

  In recent years, there have been many examples of development of solid electrolytes using high-rigidity polymer materials, and research on solid electrolytes using polymer materials with high solvent resistance has been conducted for many years. Documents 1 to 5 have developed solid electrolytes mainly composed of sulfonated polyether ether ketone, sulfonated polysulfone, and sulfonated polyether ketone. However, in any case, since the sulfonic acid group is directly bonded to the aromatic ring of the polymer main chain, there is a problem that the sulfonic acid group is gradually detached at a high operating temperature and the battery performance is lowered. In addition, since the sulfonic acid group is directly bonded to the polymer main chain, the distance between the hydrophobic main chain and the hydrophilic sulfonic acid group is short, and water molecules are absorbed more than necessary. There arises a problem that it is soluble in an aqueous solvent in an amount.

  In Patent Document 6, a solid electrolyte is produced by bonding a sulfonic acid group to an aromatic ring of a polymer main chain synthesized by polycondensation via an alkyl group. In this method, the sulfonic acid group is bonded to the main chain via a methylene chain, thereby separating the hydrophobic portion of the main chain from the hydrophilic portion of the side chain with the sulfonic acid group at a relatively long distance. The aim is to improve proton conductivity and mechanical strength. However, in reality, since the reaction efficiency is very low, the amount of sulfonic acid groups introduced is small, and the hydrophobic part of the main chain and the hydrophilic part of the side chain with sulfonic acid groups are not sufficiently separated.

JP-A-6-49202 JP-A-6-93114 JP-A-8-20716 JP-A-9-245818 Japanese Patent Laid-Open No. 10-21944 Patent registration No. 3607862

  An object of the present invention is to provide a solid electrolyte having a sufficient ion conduction performance.

  In the present invention, as a method for introducing a sulfonic acid group, instead of introducing a substituent having one sulfonic acid group, a substituent having two or more sulfonic acid groups is introduced into the polymer structure. As a result, it was found that proton conductivity can be improved while efficiently introducing sulfonic acid groups into a polymer structure while maintaining mechanical strength, and the present invention has been completed. Specifically, it was achieved by the following means.

（一般式（１）中、Ｌ¹はｎ１＋１価の連結基を表し、Ｍは、イオン性基を表し、ｎ１は２以上の整数を表す。）（３）前記一般式（１）中のＬ¹が、アルキレン基、ハロゲン置換アルキレン基、アリーレン基、ハロゲン置換アリーレン基、アルケニレン基、ハロゲン置換アルキニレン基、アルキニレン基、アミド基、エステル基、スルホン酸アミド基、スルホン酸エステル基、ウレイド基、スルホニル基、スルフィニル基、チオエーテル基、エーテル基、カルボニル基およびヘテリレン基からなる群から選択される１つの基または２つ以上を組み合わせて構成される基であって、炭素原子数０〜１００以下の基から、水素原子を（ｎ１−１）個除くことに得られる連結基である、（２）に記載の固体電解質。
（４）膜状である、（１）〜（３）のいずれかに記載の固体電解質。
（５）（１）〜（４）のいずれかに記載の固体電解質を有する電極膜接合体。
（６）（１）〜（４）のいずれかに記載の固体電解質を電極に有する電極膜接合体。
（７）一対の電極と、該電極間に設けられた（４）に記載の固体電解質を有する電極膜接合体。
（８）（５）〜（７）のいずれかに記載の電極膜接合体を含む燃料電池。
（９）ハロゲン化アルキル反応を介してスルホン酸基を導入することを特徴とする、（１）〜（４）のいずれかに記載の固体電解質の製造方法。 (1) A solid electrolyte containing a polymer compound having a group having two or more sulfonic acid groups in the main chain and / or side chain.
(2) A solid electrolyte containing a polymer compound having a group represented by the following general formula (1) in the main chain and / or side chain.
General formula (1)

(In General Formula (1), L ¹ represents an n1 + 1-valent linking group, M represents an ionic group, and n1 represents an integer of 2 or more.) (3) L in General Formula (1) ¹ is an alkylene group, halogen-substituted alkylene group, arylene group, halogen-substituted arylene group, alkenylene group, halogen-substituted alkynylene group, alkynylene group, amide group, ester group, sulfonic acid amide group, sulfonic acid ester group, ureido group, sulfonyl group A group composed of one group selected from the group consisting of a group, a sulfinyl group, a thioether group, an ether group, a carbonyl group and a heterylene group, or a combination of two or more thereof, and a group having 0 to 100 carbon atoms The solid electrolyte according to (2), which is a linking group obtained by removing (n1-1) hydrogen atoms.
(4) The solid electrolyte according to any one of (1) to (3), which is a film.
(5) An electrode membrane assembly having the solid electrolyte according to any one of (1) to (4).
(6) An electrode membrane assembly having a solid electrolyte according to any one of (1) to (4) as an electrode.
(7) An electrode membrane assembly having a pair of electrodes and the solid electrolyte according to (4) provided between the electrodes.
(8) A fuel cell comprising the electrode membrane assembly according to any one of (5) to (7).
(9) The method for producing a solid electrolyte according to any one of (1) to (4), wherein a sulfonic acid group is introduced via an alkyl halide reaction.

  According to the present invention, it has become possible to provide a solid electrolyte excellent in proton conductivity.

Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In the present specification, halogen substitution means substitution with a halogen atom (for example, a fluorine atom or a chlorine atom).
The polymer referred to in the present invention is intended to include a so-called copolymer obtained by polymerizing two or more types of monomers.

一般式（１）中、Ｌ¹はｎ１＋１価の連結基を表し、ｎ１は２以上の整数であり、２〜２０の整数が好ましく、２〜１０の整数がより好ましく、２〜５の整数がさらに好ましく、２または３が最も好ましい。 The present invention is a solid electrolyte containing a polymer compound having a group having two or more sulfonic acid groups in the main chain and / or side chain. Here, the group having two or more sulfonic acid groups means that two or more sulfonic acid groups are bonded to the main chain or the side chain via one of the groups. More preferably, the group having two or more sulfonic acid groups is a group represented by the general formula (1).
The solid electrolyte of the present invention is a solid electrolyte containing a polymer compound having a group represented by the general formula (1) in the main chain and / or side chain, and more preferably represented by the general formula (1). It is a solid electrolyte containing a polymer compound having a group in the side chain.

In the general formula (1), L ¹ represents an n1 + 1 valent linking group, n1 is an integer of 2 or more, preferably an integer of 2 to 20, more preferably an integer of 2 to 10, and an integer of 2 to 5 More preferred is 2 or 3, most preferred.

In the general formula (1), L ¹ represents an n1 + 1 valent linking group, preferably a trivalent or tetravalent linking group, and more preferably a trivalent linking group.
L ¹ is preferably an alkylene group (preferably having 1 to 20 carbon atoms (hereinafter referred to as C number), for example, methylene group, ethylene group, methylethylene group, propylene group, methylpropylene group, butylene group, pentylene group, hexylene. Group, octylene group), halogen-substituted alkylene group (preferably C 1-20, for example, difluoromethylene group, tetrafluoroethylene group, hexafluorohexylene group, tetrafluorohexylene group, dichloromethylene group), arylene group (Preferably having 6 to 26 carbon atoms, for example, 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 4-phenylenemethylene group, 1,4-naphthylene group), halogen-substituted arylene group (Preferably C number 6-26, for example 2,3,5,6-tetrafluoro-1,4- Enylene group, 2,6-difluoro-1,4-phenylene group, 2,3,5,6-tetrachloro-1,4-phenylene group, 3,4,5,6-tetrabromophenylene group), alkenylene group (Preferably having 2 to 20 carbon atoms, such as ethenylene group, propenylene group, butadienylene group), halogen-substituted alkynylene group (preferably having 2 to 20 carbon atoms, such as difluoroethenylene group, tetrafluoropropenylene group, dichloroethenylene group) Group), alkynylene group (preferably C 2-20, for example, ethynylene group, propynylene group), amide group, ester group, sulfonic acid amide group, sulfonic acid ester group, ureido group, sulfonyl group, sulfinyl group, thioether group , Ether group, carbonyl group, and heterylene group (preferably having a C number of 1 to 26, for example, 6- One group or two or more selected from the group consisting of loro-1,3,5-triazyl-2,4-diyl group, pyrimidine-2,4-diyl group, quinoxaline-2,3-diyl group) A linking group which is a group formed in combination and is a linking group obtained by removing (n1-1) hydrogen atoms from a group having 0 to 100 carbon atoms (more preferably 1 to 20 carbon atoms). To express.

Below, while indicating preferred examples of L ^1, the present invention is not limited thereto. Moreover, what has a sulfonic acid group couple | bonded in any position among the binders of the following compound is also preferable.

 In the general formula (1), M represents an ionic group, preferably a proton, an alkali metal (lithium, sodium, potassium) cation, an alkaline earth metal (potassium, strontium, barium) cation, or a quaternary ammonium (trimethyl). A proton selected from the group consisting of protonated forms of ammonium, triethylammonium, tributylammonium, benzyltrimethylammonium) cation, organic base (triethylamine, pyridine, methylimidazole, morpholine, tributylammonium, tris (2-hydroxyethyl) amine) Is more preferable.

 When the general formula (1) forms a salt, it is preferable that the proton of the acid residue is substituted with the following cation, the substitution ratio (cation / acid residue ratio) is 0 to 1, and the solid Although there is no restriction | limiting in particular in the process of electrolyte synthesis, when using as a solid electrolyte, 0.1 or less is preferable. Cations that form salts include alkali metal (lithium, sodium, potassium) cation, alkaline earth metal (potassium, strontium, barium) cation, quaternary ammonium (trimethylammonium, triethylammonium, tributylammonium, benzyltrimethylammonium) Protonates of cations and organic bases (triethylamine, pyridine, methylimidazole, morpholine, tributylammonium, tris (2-hydroxyethyl) amine) are preferred, alkali metal cations and ammonium cations are more preferred, and alkali metal cations are particularly preferred.

Although the preferable example of group represented by General formula (1) below is shown, this invention is not limited to these. Moreover, what has a sulfonic acid group couple | bonded in any position among the binders of the following compound is also preferable.

The polymer compound contained in the solid electrolyte of the present invention is not particularly defined, but is preferably a polysulfone, polyketone, polyamide, polyether, polystyrene, fluororesin, or polyolefin compound, and an aromatic ring The compound containing is more preferable.
Although the main chain structure of the high molecular compound which the solid electrolyte of this invention has is shown below, this invention is not limited to these. These main chain structures are preferably those in which two or more are combined. Among the following, 1-6, 1-7, 2-17, 2-18, 2-19, 2-20, 2-21, 2-22, 3-1, 3-2, 3-3, 3 -4, 3-5, 3-6, 3-7, 3-14 and 3-15 are preferred.

（ここで、Ｒ¹³、Ｒ¹⁴は、それぞれ、炭素数１〜１０の、置換または無置換のアルキル基またはフェニル基である。）

(Here, R ¹³ and R ¹⁴ are each a substituted or unsubstituted alkyl group or phenyl group having 1 to 10 carbon atoms.)

Here, in the following structure, a group containing two or more sulfonic acid groups (preferably, a group represented by the general formula (1)) may be bonded to any position, and the main chain structure. May be bonded through some group.
When bonded through any group, such groups include alkylene groups, halogen-substituted alkylene groups, arylene groups, halogen-substituted arylene groups, alkenylene groups, halogen-substituted alkynylene groups, alkynylene groups, amide groups, ester groups. A sulfonic acid amide group, a sulfonic acid ester group, a ureido group, a sulfonyl group, a sulfinyl group, a thioether group, an ether group, a carbonyl group, and a heterylene group. Group.
The polymer compound contained in the solid electrolyte of the present invention is a group represented by the general formula (1) and may contain two or more different groups.

 As an example of a method for synthesizing a polymer compound having a group represented by the general formula (1) in the main chain and / or side chain, a sulfone compound represented by the following general formula (26): And a production method in which an aromatic diol represented by the following general formula (27) is polycondensed.

一般式（２６）中、Ｘ¹およびＸ²は、それぞれ、ハロゲン原子（好ましくは、フッ素原子、塩素原子）またはニトロ基を表す。 General formula (26)

In General Formula (26), X ¹ and X ² each represent a halogen atom (preferably a fluorine atom or a chlorine atom) or a nitro group.

Formula (27)

In general formula (27), each A independently represents a divalent group selected from —C (R ⁵ R ⁶ ) —, —O—, —S—, —CO—, —SO—, —SO ₂ —. R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, a benzyl group, etc.), an alkenyl group, an aryl group, a halogen-substituted alkyl group (for example, a trifluoromethyl group, Pentafluoroethyl group), preferably —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —O—, —S—, —CO—, —SO ₂ —.
m is 0, 1 or 2.
R and R ⁱ are each independently an alkyl group having 1 to 10 carbon atoms, and s and s ⁱ are 0 to
It is an integer of 4.

Specific examples of the sulfonic acid group-containing polymer compound represented by the general formula (26) include the compounds represented below.

  These sulfone compounds can be used alone or in admixture of two or more.

Examples of the compound represented by the general formula (27) include hydroquinone, resorcin, 2-methylhydroquinone, 2-ethylhydroquinone, 2-propylhydroquinone, 2-butylhydroquinone, 2-hexylhydroquinone, 2-octylhydroquinone, 2- Decanyl hydroquinone, 2,3-dimethylhydroquinone, 2,3-diethylhydroquinone, 2,5-dimethylhydroquinone, 2,5-diethylhydroquinone, 2,6-dimethylhydroquinone, 2,3,5-trimethylhydroquinone, 2, 3,5,6-tetramethylhydroquinone, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 3,3′-dimethyl-4,4′-dihydroxybiphenyl, 3,3 ′, 5,5 ′ -Tetramethyl-4,4'-dihydride Roxybiphenyl, 3,3′-dichloro-4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetrachloro-4,4′-dihydroxybiphenyl, 3,3′-dibromo-4,4 ′ -Dihydroxybiphenyl, 3,3 ', 5,5'-tetrabromo-4,4'-dihydroxybiphenyl, 3,3'-difluoro-4,4'-dihydroxybiphenyl, 3,3', 5,5'-tetra Fluoro-4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenylmethane, 2,2′-dihydroxydiphenylmethane, 3,3′-dimethyl-4,4′-dihydroxydiphenylmethane, 3,3 ′, 5,5 ′ -Tetramethyl-4,4'-dihydroxydiphenylmethane, 3,3'-dichloro-4,4'-dihydroxydiphenylmethane, 3,3 ', 5,5'-tetrachloro-4, '-Dihydroxydiphenylmethane, 3,3'-dibromo-4,4'-dihydroxydiphenylmethane, 3,3', 5,5'-tetrabromo-4,4'-dihydroxydiphenylmethane, 3,3'-difluoro-4,4 '-Dihydroxydiphenylmethane, 3,3'5,5'-tetrafluoro-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 2,2'-dihydroxydiphenyl ether, 3,3'-dimethyl-4, 4'-dihydroxydiphenyl ether, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxydiphenyl ether, 3,3'-dichloro-4,4'-dihydroxydiphenyl ether, 3,3', 5,5 '-Tetrachloro-4,4'-dihydroxydiphenyl ether, 3,3'-dibromo-4,4'-dihi Roxydiphenyl ether, 3,3 ′, 5,5′-tetrabromo-4,4′-dihydroxydiphenyl ether, 3,3′-difluoro-4,4′-dihydroxydiphenyl ether, 3,3 ′, 5,5′-tetrafluoro -4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 2,2'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5 5'-tetramethyl-4,4'-dihydroxydiphenyl sulfide, 3,3'-dichloro-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'-tetrachloro-4,4'-dihydroxy Diphenyl sulfide, 3,3′-dibromo-4,4′-dihydroxydiphenyl sulfide, 3,3 ′, 5,5 ′ -Tetrabromo-4,4'-dihydroxydiphenyl sulfide, 3,3'-difluoro-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'-tetrafluoro-4,4'-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenylsulfone, 2,2′-dihydroxydiphenylsulfone, 3,3′-dimethyl-4,4′-dihydroxydiphenylsulfone, 3,3 ′, 5,5′-tetramethyl-4,4 '-Dihydroxydiphenylsulfone, 3,3'-dichloro-4,4'-dihydroxydiphenylsulfone, 3,3', 5,5'-tetrachloro-4,4'-dihydroxydiphenylsulfone, 3,3'-dibromo -4,4'-dihydroxydiphenylsulfone, 3,3 ', 5,5'-tetrabromo-4,4'-dihydroxydiphenyls Hong, 3,3′-difluoro-4,4′-dihydroxydiphenylsulfone, 3,3 ′, 5,5′-tetrafluoro-4,4′-dihydroxydiphenylsulfone, 2,2-bis (4-hydroxyphenyl) ) Propane, 2,2-bis (2-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-didibromo-4- Hydroxyphenyl) propane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphene) ) Propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, α, α′-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene, α, α′-bis ( 2-hydroxyphenyl) -1,4-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene, α, α′-bis (2-hydroxyphenyl) -1,3- Diisopropylbenzene, α, α′-bis (3-methyl-4-hydroxyphenyl) -1,4-diisopropylbenzene, α, α′-bis (3,5-dimethyl-4-hydroxyphenyl) -1,4- Diisopropylbenzene, α, α′-bis (3-methyl-4-hydroxyphenyl) -1,3-diisopropylbenzene, α, α′-bis (3,5-dimethyl-4-hydroxy Phenyl) -1,3-diisopropylbenzene and the like.
These aromatic diols can be used alone or in admixture of two or more.

  The ratio of the compound represented by the general formula (26) and the compound represented by the general formula (27) is represented by the general formula (26) with respect to 1 mol of the compound represented by the general formula (27). The compound (molar ratio) represented is preferably 0.9 to 1.1 mol, more preferably 0.93 to 1.07, and still more preferably 0.95 to 1.05.

  When the compound represented by the general formula (26) and the compound represented by the general formula (27) are polycondensed to synthesize the protonic acid group-containing polysulfone of the present invention, the polymerization is carried out in the presence of a basic compound. A condensation method is preferably used.

  The kind of basic compound, reaction conditions, and the like are not particularly defined, and known basic compounds and reaction conditions can be applied. Examples of basic compounds include basic metal compounds such as alkali metals and alkaline earth metals, carbonates, acetates, hydroxides, quaternary ammonium salts, phosphonium salts and organic bases of various metals.

  0.05-10.0 mol is preferable with respect to 1 mol of the compound represented by General formula (27), and, as for the usage-amount of these catalysts, 0.1-4.0 mol is more preferable, and 0.0. 5-2.5 mol is more preferable.

The reaction for producing the protonic acid group-containing polymer compound of the present invention is usually carried out in a solvent.
The following are mentioned as a preferable solvent.
1) ether solvent 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, tetrahydrofuran, bis [2- (2-methoxyethoxy) ethyl] ether, 1,4-dioxane and the like.
2) Aprotic amide solvents N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N -Methylcaprolactam, hexamethylphosphorotriamide and the like.
3) Amine solvents pyridine, quinoline, isoquinoline, α-picoline, β-picoline, γ-picoline, isophorone, piperidine, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine etc.
4) Other solvents: dimethyl sulfoxide, dimethyl sulfone, diphenyl ether, sulfolane, diphenyl sulfone, tetramethyl urea, anisole and the like.

  These solvents may be used alone or in combination of two or more. Further, one or more of the solvents shown in the following item 5) may be further mixed and used. When mixed and used, it is not always necessary to select a combination of solvents that are mutually soluble in an arbitrary ratio, and they may be mixed or non-uniform.

  The concentration of the reaction carried out in these solvents (hereinafter referred to as polymerization concentration) can be adjusted without particular limitation without departing from the gist of the present invention.

  A proton acid group-containing polysulfone is obtained by reacting the compound represented by the general formula (27) with the compound represented by the general formula (26) in the above solvent. A particularly preferred solvent for this reaction is a combination of the aprotic amide solvent of the above item 2) and the dimethyl sulfoxide of the item 4).

  The atmosphere is not particularly limited, but air, nitrogen, helium, neon and argon are preferably used, and nitrogen or argon which is an inert gas is preferable.

Furthermore, in order to remove water generated by the reaction out of the system, another solvent may be allowed to coexist. Examples of the solvent used here include the following 5).
5) benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, bromobenzene, o-dibromobenzene, m-dibromo Examples include benzene, p-dibromobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-bromotoluene, m-bromotoluene, and p-bromotoluene. These solvents may be used alone or in combination of two or more.

  In addition, two or more of the solvents shown in the above items 1) to 5) can be mixed and used. When mixed and used, it is not always necessary to select a combination of solvents that are mutually soluble in an arbitrary ratio, and they may be mixed or non-uniform. There is no limit to the amount of these dehydrating agents used.

  There are no particular limitations on the reaction temperature, reaction time, and reaction pressure, and known conditions can be applied. For example, the reaction temperature is preferably 0 to 300 ° C, more preferably 100 to 270 ° C, and still more preferably 130 ° C to 250 ° C. Moreover, although reaction time can be suitably determined according to the kind of monomer to be used, the kind of solvent, and reaction temperature, it is preferably 1 to 72 hours, more preferably 3 to 48 hours, and further 5 to 24 hours. preferable. The reaction pressure may be under pressure or under reduced pressure, but may be normal pressure.

As a method for introducing a sulfonic acid group into the above polymer compound, the following introduction method can be used. If it has an aromatic group, it can be introduced directly into the polymer or after introduction into the monomer. It may be molecularized.
For example, when L ¹ is a methylene group, a halogenomethylated polysulfone using a halogenomethylating agent such as chloromethyl methyl ether described later, a compound containing a hydroxyl group in the structure and having a plurality of sodium sulfonate sites, Examples thereof include a method in which a compound as shown below is reacted by a general synthetic method of Williamson-ether synthesis.
For the synthesis of these compounds, methods such as oxidation of dithiolane alcohol, reduction and oxidation of thiolane carboxylic acid and ester, reduction and oxidation of dithiancarboxylic acid and ester may be used.

Alternatively, after halogenomethylated polysulfone is hydrolyzed with NaOH or CaCO ₃ to introduce a hydroxyl group, the reaction may be carried out using, for example, a compound as shown below or a compound in which the hydroxyl group of the above compound group is converted to halogen or sulfonate. it can.

Further, after halogenomethylated polysulfone is hydrolyzed with NaOH or CaCO ₃ to introduce a hydroxyl group, for example, a compound shown below can be reacted to introduce a plurality of sulfonic acid groups.

  In the present invention, the halogenoalkyl group includes a chloromethyl group, bromomethyl group, iodomethyl group, chloroethyl group, bromoethyl group, iodoethyl group, chloropropyl group, bromopropyl group, iodopropyl group, chlorobutyl group, bromobutyl group, iodobutyl group, Examples include halogenated alkyl groups (C number is preferably 1 to 6) such as chloropentyl group, bromopentyl group, iodopentyl group, chlorohexyl group, bromohexyl group, iodohexyl group, and the like, and halogenated methyl groups are preferable.

  In order to introduce a halogenated methyl group preferable in the present invention into an aromatic ring (halogenomethylation reaction of an aromatic ring), known reactions can be widely used. For example, chloromethyl methyl ether, 1,4-bis (chloromethoxy) butane, 1-chloromethoxy-4-chlorobutane, etc. are used as chloromethylating agents, and tin chloride, zinc chloride, aluminum chloride, titanium chloride, etc. are used as catalysts. A chloromethyl group can be introduced into the aromatic ring by performing a chloromethylation reaction using Lewis acid, hydrofluoric acid, or the like. The solvent is preferably dichloroethane, trichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, nitrobenzene, etc., and the reaction is preferably carried out in a homogeneous system. Moreover, a methyl halide group can also be introduce | transduced into an aromatic ring using paraformaldehyde, hydrogen chloride, or hydrogen bromide.

  The amount of the sulfonic acid group in the polymer compound obtained as described above is preferably 0.05 to 6 and more preferably 0.3 to 4 with respect to the unit constituting the polymer. . When the number is 0.05 or more, proton conductivity is improved, and when the number is 6 or less, the hydrophilicity is excessively improved to become a water-soluble polymer, or the durability is lowered. Can be suppressed more effectively.

  The molecular weight of the precursor polymer before sulfonation of the polymer compound of the present invention thus obtained is a polystyrene-equivalent weight average molecular weight, preferably 1,000 to 1,000,000, more preferably 1. , 500 to 200,000. By setting it as 1,000 or more, it can make a crack difficult to generate | occur | produce in a molded film, a coating-film property becomes more favorable, and an intensity | strength property improves more. On the other hand, by setting it to 1,000,000 or less, solubility becomes more preferable, and problems such as high solution viscosity and poor processability can be more effectively suppressed.

The structure of the sulfonic acid group-containing polymer compound of the present invention, the infrared absorption spectrum, 1,030~1,045cm ^-1, S = O absorption at 1,160~1,190cm ^-1, 1,130~ C-O-C absorption at 2090 cm @ ^-1, confirmed by like C = O absorption of 1,640～1,660Cm ^-1, these composition ratio, neutralization titration of sulfonic acid or learned by elemental analysis be able to. Moreover, the structure can be confirmed from the peak of the aromatic proton at 6.8 to 8.0 ppm by nuclear magnetic resonance spectrum ( ¹ H-NMR).

  Next, the proton conductive membrane of the present invention is composed of the sulfonic acid group-containing copolymer, but besides the sulfonic acid group-containing copolymer, an inorganic acid such as sulfuric acid and phosphoric acid, an organic acid containing a carboxylic acid, An appropriate amount of water may be used in combination.

  When the solid electrolyte of the present invention finally becomes a solid electrolyte containing a polymer compound having a group having two or more sulfonic acid groups in the main chain and / or side chain, a blend with another polymer compound or It is possible to adjust appropriately such as making a copolymer of a monomer containing a group having two or more sulfonic acid groups and a monomer having no sulfonic acid group.

  When the solid electrolyte of the present invention is used as a proton conductive material, it needs to be converted into a proton type. This step is performed by immersing the solid electrolyte in an acidic solution. As the acidic solution, a protonic acid solution is preferable. Examples of the protonic acid include hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, tetrafluoroboric acid, hexafluoroarsenic acid, hydrobromic acid, solid acid (tungstophosphoric acid, tungsten peroxo complex). etc.) and the like, sulfonic acids (e.g., a sulfonic acid of 1 to 15 carbon atoms, benzenesulfonic acid, toluenesulfonic acid, hexafluoro benzenesulfonic acid, trifluoromethanesulfonic acid, dodecyl sulfonic acid). Two or more of these may be used in combination. In particular, hydrochloric acid or nitric acid is preferable. 10-100 degreeC is preferable and the temperature in this process has more preferable 20-80 degreeC. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours. The concentration of the acid solution is preferably 0.1 to 10 N, and more preferably 0.5 to 5 N.

  Next, the solid electrolyte of the present invention comprises the sulfonic acid group-containing copolymer. In addition to the sulfonic acid group-containing copolymer, an inorganic acid such as sulfuric acid and phosphoric acid, an organic acid containing a carboxylic acid, an appropriate amount Water may be used in combination.

  The obtained solid electrolyte can be used, for example, as a proton conductive electrolyte or an electrode electrolyte.

 When used for a proton conductive electrolyte membrane, the shape is preferably a membrane, and the thickness of the proton conductive electrolyte membrane is preferably 10 to 500 μm, more preferably 25 to 150 μm. It may be in the form of a film at the time of molding, or may be cut into a film after being formed into a bulk body. In the film forming process, the liquid was maintained a polymer compound as a raw material to above the melting point temperature or by using a liquid prepared by dissolving with a solvent, a film may be formed by extrusion molding, cast these liquids Alternatively, it may be formed by coating. These operations can be performed with a film forming machine using a roll such as a calendar roll or a cast roll or a T-die, and can also be a press forming using a press machine. Further, a stretching process may be added to control film thickness and improve film characteristics.

  Furthermore, surface treatment may be performed after the film forming step. As the surface treatment, rough surface treatment, surface cutting, removal, and coating treatment may be performed, which may improve the adhesion with the electrode.

 In addition, it is possible to form a film by impregnating the solid electrolyte of the present invention into the pores of the porous substrate. The reaction solution after completion of the second step of the present invention may be applied and impregnated on a substrate having pores, or the substrate may be immersed in the reaction solution to fill the pores with a solid electrolyte to form a film. . Preferable examples of the substrate having pores include porous polypropylene, porous polytetrafluoroethylene, porous cross-linked heat-resistant polyethylene, and porous polyimide.

 Further, if necessary, the modification treatment may be performed by performing a heat treatment in a conditioned environment and a radiation (visible light, ultraviolet ray, γ ray, electron beam, etc.) irradiation treatment. Moreover, you may add the washing | cleaning process and drying process by water, an organic solvent, etc. for the purpose of removing an unnecessary component after a bridge | crosslinking process.

Other components of solid electrolyte To improve the membrane characteristics, the solid electrolyte of the present invention may contain an antioxidant, fibers, fine particles, water-absorbing agent, plasticizer, compatibilizer, and the like, if necessary. The content of these additives is preferably in the range of 1 to 30% by mass with respect to the total amount of the solid electrolyte.

  Antioxidants include (hindered) phenolic, monovalent or divalent sulfur, trivalent to pentavalent phosphorus, benzophenone, benzotriazole, hindered amine, cyanoacrylate, salicylate, oxalic Acid anilide compounds are 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-2000-231828, JP-A-2001-307545. Examples thereof include fibers described in JP-A No. 2003-317748, JP-A No. 2004-63430, and JP-A No. 2004-107461.

  Examples of the fine particles include fine particles made of silica, alumina, titanium oxide, zirconium oxide, and the like. Specifically, Japanese Patent Application Laid-Open Nos. 6-1111834, 2003-178777, and 2004-217921. Fine particles described in the publication can be mentioned.

  Water-absorbing agents (hydrophilic substances) include cross-linked polyacrylate, starch-acrylate, poval, polyacrylonitrile, carboxymethylcellulose, polyvinylpyrrolidone, polyglycol dialkyl ether, polyglycol dialkyl ester, silica gel, synthetic zeolite, alumina gel , Titania gel, zirconia gel, and yttria gel are preferable examples. Specific examples include water absorbing agents described in JP-A Nos. 7-13003, 8-20716, and 9-251857. .

  Plasticizers include phosphate ester compounds, phthalate ester compounds, aliphatic monobasic acid ester compounds, aliphatic dibasic acid ester compounds, dihydric alcohol ester compounds, oxyacid ester compounds, and chlorination. Paraffin, alkylnaphthalene compounds, sulfonalkylamide compounds, oligoethers, carbonates, and aromatic nitriles are preferable examples, and specifically, JP2003-970030A and JP2003-288916A. And plasticizers described in JP-A No. 2003-317539.

Further, the polymer electrolyte of the present invention may contain various polymer compounds for the purpose of (1) increasing the mechanical strength of the film and (2) increasing the acid concentration in the film.
(1) For the purpose of increasing mechanical strength, a polymer compound having a molecular weight of about 10,000 to 1,000,000 and having good compatibility with the solid electrolyte of the present invention is suitable. For example, perfluorinated polymer, polystyrene, polyethylene glycol, polyoxetane, poly (meth) acrylate, polyether ketone, polyether sulfone, and two or more polymers thereof are preferable, and the content is 1 to 30 based on the total. A range of mass% is preferred.

The compatibilizer preferably has a boiling point or sublimation point of 250 ° C. or higher, more preferably 300 ° C. or higher.
(2) For the purpose of increasing the acid concentration, perfluorocarbon sulfonic acid polymer represented by Nafion, poly (meth) acrylate having a phosphate group in the side chain, sulfonated polyetheretherketone, sulfonated polyethersulfone, sulfone Polymer compounds having a ptronic acid moiety such as sulfonated products of heat-resistant aromatic polymers such as sulfonated polysulfone and sulfonated polybenzimidazole are preferable, and the content is preferably in the range of 1 to 30% by mass.

As the characteristics of the solid electrolyte of the present invention, those having the following performances are preferred.
For example, the ionic conductivity is preferably 0.005 S / cm or more, more preferably 0.01 S / cm or more at 25 ° C. and 95% relative humidity.
For example, the tensile strength is preferably 350 kg / cm ² or more, particularly preferably 450 kg / cm ² or more.
As for durability, the rate of change in weight and ion exchange capacity is preferably 20% or less, particularly preferably 10% or less, before and after aging at a constant temperature in 30% hydrogen peroxide. Furthermore, the volume swelling rate at a constant temperature in ion-exchanged water is preferably 10% or less, and particularly preferably 5% or less.
The solid electrolyte of the present invention preferably has a stable water absorption and water content. Moreover, the thing whose solubility is a grade which can be disregarded substantially with respect to alcohol, water, and these mixed solvents is preferable. Moreover, the thing which is a grade which can be substantially disregarded in the weight reduction and shape change when immersed in the said solvent is preferable.
When formed into a film, the ion conduction direction is preferably such that the direction from the front surface to the back surface is higher than the other directions.
The heat resistant temperature of the solid electrolyte of the present invention is preferably 100 ° C. or higher, more preferably 150 ° C. or higher, and further preferably 200 ° C. or higher. The heat resistant temperature can be defined as, for example, the time when the weight loss reaches 5% when heated at a rate of 1 ° C./min. This weight loss is calculated excluding evaporation such as moisture.

Fuel Cell The solid electrolyte of the present invention can be used for an electrode membrane assembly (hereinafter referred to as “MEA”) and a fuel cell using the electrode membrane assembly.
FIG. 1 shows an example of a schematic cross-sectional view of the electrode membrane assembly of the present invention. The MEA 10 includes a membrane-shaped solid electrolyte 11 and an anode electrode 12 and a cathode electrode 13 that are opposed to each other with the membrane-like solid electrolyte 11 interposed therebetween.
The anode electrode 12 and the cathode electrode 13 are composed of porous conductive sheets (for example, carbon paper) 12a and 13a and catalyst layers 12b and 13b. The catalyst layers 12b and 13b are made of a dispersion in which carbon particles (for example, ketjen black, acetylene black, carbon nanotubes, etc.) carrying a catalyst metal such as platinum particles are dispersed in a proton conductive material (eg, Nafion). . In order to bring the catalyst layers 12b and 13b into close contact with the solid electrolyte 11, the porous conductive sheets 12a and 13a coated with the catalyst layers 12b and 13b may be pressure-bonded to the solid electrolyte 11 by a hot press method or appropriately supported. Generally, a method in which the catalyst layers 12b and 13b coated on the body are pressure-bonded while being transferred to the solid electrolyte 11 and then sandwiched between the porous conductive sheets 12a and 13a is generally used.

  A method for manufacturing the electrode will be described. The solid electrolyte of the present invention is dissolved in a solvent and mixed and dispersed with platinum-supporting carbon. Solvents at this time are heterocyclic compounds (3-methyl-2-oxazolidinone, N-methylpyrrolidone, etc.), cyclic ethers (dioxane, tetrahydrofuran, etc.), chain ethers (diethyl ether, ethylene glycol dialkyl ether, propylene glycol dialkyl). Ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, isopropanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.), many Polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol, poly Pyrene glycol, glycerin, etc.), nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, etc.), nonpolar solvents (toluene, xylene, etc.), chlorinated solvents (methylene chloride, ethylene chloride, etc.), Amides (N, N-dimethylformamide, N, N-dimethylacetamide, acetamide, etc.), water and the like are preferably used, and among these, heterocyclic compounds, alcohols, polyhydric alcohols and amides are preferably used.

  The dispersion method may be a method using stirring, but ultrasonic dispersion, ball mill, or the like can also be used. The obtained dispersion can be applied using the above-described application method.

  Application of the dispersion will be described. In the coating step, the dispersion may be used to form a film by extrusion molding, or these dispersions may be cast or applied to form a film. Although a support body is not specifically limited, As a preferable example, a glass substrate, a metal substrate, a polymer film, a reflecting plate, etc. can be mentioned. Examples of the polymer film include cellulose polymer films such as triacetyl cellulose (TAC), ester polymer films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and fluorine such as polytrifluoroethylene (PTFE). Examples thereof include a polymer film and a polyimide film. The coating method may be a known method, for example, using curtain coating method, extrusion coating method, roll coating method, spin coating method, dip coating method, bar coating method, spray coating method, slide coating method, print coating method, etc. Can do. In particular, when a conductive porous body (carbon paper, carbon cloth) is used as a support, a catalyst electrode can be directly produced.

 These operations can be performed by a film forming machine using a roll such as a calendar roll or a cast roll or a T die, or can be a press forming using a press machine. Further, a stretching process may be added to control film thickness and improve film characteristics.

The drying temperature of the coating process is related to the drying speed and can be selected according to the properties of the material. Preferably it is -20 degreeC-150 degreeC, More preferably, it is 20 degreeC-120 degreeC, More preferably, it is 50 degreeC-100 degreeC.
The drying time is preferably 1 minute to 48 hours, more preferably 5 minutes to 10 hours, and particularly preferably 10 minutes to 5 hours. By setting it to 48 hours or less, it is more preferable from the viewpoint of productivity, but by setting it to 1 minute or more, defects such as bubbles and surface irregularities can be effectively suppressed. For this reason, control of humidity is also important, and 25 to 100% RH is preferable, and 50% to 95% is more preferable.

  The coating solution in the coating step preferably has a low content of metal ions, and particularly preferably has a low amount of transition metal ions, especially iron ions, nickel ions and cobalt ions. The content is preferably 500 ppm or less, particularly preferably 100 ppm or less. Therefore, the solvent used in the above-mentioned process is also preferably a solvent having a low content of these ions.

  Furthermore, surface treatment may be performed after the film forming step. As the surface treatment, rough surface treatment, surface cutting, removal, and coating treatment may be performed, which may improve the adhesion with the solid electrolyte membrane or the porous conductor.

In order to bring the catalyst layers 12b and 13b into close contact with the solid electrolyte membrane 11, the porous conductive sheets 12a and 13a coated with the catalyst layers 12b and 13b are applied to the solid electrolyte 11 membrane by hot pressing (preferably 120 to 130). Pressure bonding at ² ° C. and 2 to 100 kg / cm ² ), or after applying the catalyst layers 12b and 13b coated on a suitable support to the solid electrolyte 11 while being transferred, the porous conductive sheets 12a and 13a In general, the method of sandwiching with is preferably used.

  FIG. 2 shows an example of a fuel cell structure. The fuel cell includes an MEA 10, a pair of separators 21 and 22 that sandwich the MEA 10, and a current collector 17 and a packing 14 made of a stainless steel net attached to the separators 21 and 22. An anode pole side opening 15 is provided in the anode pole side separator 21, and a cathode pole side opening 16 is provided in the cathode pole side separator 22. From the anode side opening 15, hydrogen, alcohol is supplied liquid fuel such as gas fuel or aqueous alcohol (methanol, etc.) or the like, from the cathode side opening 16, an oxygen gas, an oxidant gas such as air Is supplied.

  The active polarization in the hydrogen-oxygen fuel cell is larger in the cathode electrode (air electrode) than in the anode electrode (hydrogen electrode). This is because the cathode electrode reaction (oxygen reduction) is slower than 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 an aqueous methanol solution as an anode fuel, it is important to suppress catalyst poisoning due to CO that occurs during the oxidation process of methanol. For this purpose, platinum-based binary metals such as Pt—Ru, Pt—Fe, Pt—Ni, Pt—Co, Pt—Mo, Pt—Ru—Mo, Pt—Ru—W, Pt—Ru—Co Platinum-based ternary metals such as Pt—Ru—Fe, Pt—Ru—Ni, Pt—Ru—Cu, Pt—Ru—Sn, and 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 function of the catalyst layer was caused 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) redox. (4) transporting protons generated by the reaction to the solid electrolyte. For (1), the catalyst layer needs to be porous so that liquid and gaseous fuel can permeate deeply. (2) is the active metal catalyst described above, and (3) is the same carbon material as described above. In order to fulfill the function (4), a proton conductive material is mixed in the catalyst layer.

  The proton conductive material of the catalyst layer is not limited as long as it is a solid having a proton donating group, polymer compounds having an acid residue used for the solid electrolyte (e.g. a perfluorocarbon sulfonic acid represented by Nafion, side A sulfonated product of a heat-resistant aromatic polymer such as a chain phosphate group poly (meth) acrylate, a sulfonated polyetheretherketone, and a sulfonated polybenzimidazole is preferably used. When the solid electrolyte of the present invention is used for the catalyst layer, the material is the same type as that of the solid electrolyte, so that the electrochemical adhesion between the solid electrolyte and the catalyst layer is increased, which is more advantageous.

The amount of active metal used is suitably in the range of 0.03 to 10 mg / cm ² from the viewpoint of battery output and economy. The amount of the carbon material supporting the active metal is suitably 1 to 10 times the mass of the active metal. The amount of the proton conductive material is suitably 0.1 to 0.7 times the mass of the active metal-carrying carbon.

  It is also called an electrode substrate, a permeable layer, or a backing material, and plays a role of preventing current collection and water accumulation and deterioration of gas permeation. Usually, carbon paper or carbon cloth can be used, and polytetrafluoroethylene (PTFE) treated for water repellency can be used.

The following four methods are preferable for the production of MEA.
(1) Proton conductive material coating method: A catalyst paste (ink) based on active metal-supported carbon, proton conductive material, and solvent is directly applied to both sides of the solid electrolyte, and a porous conductive sheet is (thermally) pressed. A 5-layer MEA is fabricated.
(2) Porous conductive sheet coating method: After applying a catalyst paste to the surface of the porous conductive sheet to form a catalyst layer, it is pressure-bonded to a solid electrolyte to produce a MEA having a five-layer structure.
(3) Decal method: After applying a catalyst paste on PTFE to form a catalyst layer, only the catalyst layer is transferred to a solid electrolyte to form a three-layer MEA, and a porous conductive sheet is pressure-bonded to form five layers. An MEA having a configuration is manufactured.
(4) Post-catalyst support method: After applying and forming an ink in which a platinum unsupported carbon material is mixed with a proton conductive material on a solid electrolyte, a porous conductive sheet, or PTFE, and impregnating the solid electrolyte with platinum ions, Platinum particles are reduced and deposited in the film to form a catalyst layer. After forming the catalyst layer, the MEA is produced by the above methods (1) to (3).

  The anode fuel that can be used as the fuel of the fuel cell using the solid electrolyte of the present invention is hydrogen, alcohols (methanol, isopropanol, ethylene glycol, etc.), ethers (dimethyl ether, dimethoxymethane, trimethoxymethane, etc.) ), Formic acid, borohydride complexes, ascorbic acid and the like. Examples of the cathode fuel include oxygen (including oxygen in the atmosphere) and hydrogen peroxide.

In a direct methanol fuel cell, which is synonymous with a polymer electrolyte fuel cell, a methanol aqueous solution having a methanol concentration of 3 to 64% by mass is used as an 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 mass. The higher the methanol concentration, there is an advantage that the mass 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 diffusibility of the solid electrolyte used. The cathode reaction formula of the direct methanol fuel cell is (3 / 2O ₂ + 6H ⁺ + 6e ⁻ → H ₂ O), and oxygen (usually oxygen in the air) is used as the fuel.

  The methods for supplying the anode fuel and the cathode fuel to the respective catalyst layers include (1) a method of forced circulation using an auxiliary device such as a pump (active type), and (2) a method not using an auxiliary device ( For example, in the case of a liquid, there are two types, that is, a passive type in which the catalyst layer is exposed to the atmosphere and supplied in the case of a gas due to capillary action or natural fall. An active type capable of obtaining high output is preferable.

  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 the single cells are arranged on a plane and “bipolar stacking” in which the single cells are stacked via separators having fuel flow paths formed on both sides 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.

 The fuel cell is considered for various uses such as transportation, home use, and portable equipment. For example, preferable transportation applications include automobiles (passenger cars, freight cars, motorcycles, personal beagles), ships, For home use, cogeneration systems, vacuum cleaners, robots, and portable devices include mobile phones, notebook computers, electronic still cameras, PDAs, video cameras, and portable game machines. Furthermore, it can be used for portable generators, outdoor lighting devices, and the like. Moreover, it can 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 and capacitors mounted on these devices.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Ion conductivity measurement method]
A solid electrolyte sample is punched out into a circle having a diameter of 5 mm, sandwiched between two stainless steel plates, and ion conductivity at 25 ° C. and relative humidity of 95% is measured by an alternating current impedance method.

Example 1 Production of Solid Electrolyte Using 2,2-bis (4-hydroxyphenyl) propane and bis (4-chlorophenylphenyl) sulfone as monomers, Maruzen: Fourth Edition Experimental Chemistry Course, Vol. 28, Polymer Synthesis, P.A. According to the polymerization method in 357, polysulfone (I) is synthesized. Next, a chloromethyl group is introduced by a chloromethylation method (described in Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 39, 2943-2950, 2001). The chloromethylated polysulfone (III) is reacted with the compound (IV) by a Williamson-ether synthesis method to perform salt exchange to obtain a sulfonated polysulfone (V). The ionic conductivity is measured according to the following method.

Example 2 Production of Solid Electrolyte Using 4- (4′-phenoxy) phenoxybenzoic acid, Maruzen: 4th Edition Experimental Chemistry Course, Vol. 28, Polymer Synthesis, p. According to the polymerization method at 185, polyetheretherketone (PEEK) (VI) is synthesized. Next, a chloromethyl group is introduced by a chloromethylation method (described in Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 39, 2943-2950, 2001). The chloromethylated polysulfone (VIII) is reacted with the compound (IX) by the Williamson-ether synthesis method to perform salt exchange to obtain the sulfonated polysulfone (X). The ionic conductivity is measured according to the following method.

It is a schematic sectional drawing which shows the structure of the electrode membrane assembly using the solid electrolyte of this invention. It is a schematic sectional drawing which shows an example of the structure of the fuel cell of this invention.

Explanation of symbols

10 ... Fuel cell electrode membrane composite (MEA)
11 ... Solid electrolyte
12 ... Anode electrode
12a ... Anode porous conductive sheet
12b ... Anode electrode catalyst layer
13 ... Cathode electrode
13a ... Cathode porous conductive sheet
13b ... Cathode electrode catalyst layer
14 ... Packing
15 ... Anode pole side opening
16 ... Cathode pole side opening
17 ... current collector
21,22 ... Separator

Claims (9)

A solid electrolyte comprising a polymer compound having a group having two or more sulfonic acid groups in the main chain and / or side chain. The solid electrolyte containing the high molecular compound which has group represented by following General formula (1) in a principal chain and / or a side chain.
General formula (1)

(In the general formula (1), L ¹ represents an n1 + 1 valent linking group, M represents an ionic group, and n1 represents an integer of 2 or more.) L ¹ in the general formula (1) is an alkylene group, a halogen-substituted alkylene group, an arylene group, a halogen-substituted arylene group, an alkenylene group, a halogen-substituted alkynylene group, an alkynylene group, an amide group, an ester group, a sulfonic acid amide group, A group composed of one group selected from the group consisting of a sulfonate group, a ureido group, a sulfonyl group, a sulfinyl group, a thioether group, an ether group, a carbonyl group, and a heterylene group, or a combination of two or more thereof, The solid electrolyte according to claim 2, which is a linking group obtained by removing (n1-1) hydrogen atoms from a group having 0 to 100 carbon atoms. The solid electrolyte according to any one of claims 1 to 3, which is in a film form. The electrode membrane assembly which has a solid electrolyte of any one of Claims 1-4. The electrode membrane assembly which has a solid electrolyte of any one of Claims 1-4 in an electrode. The electrode membrane assembly which has a solid electrolyte of Claim 4 provided between a pair of electrode and this electrode. A fuel cell comprising the electrode membrane assembly according to any one of claims 5 to 7. The method for producing a solid electrolyte according to any one of claims 1 to 4, wherein a sulfonic acid group is introduced via an alkyl halide reaction.

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