JP2008198936A - Electrochemical capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability electrochemical capacitor having excellent electricity storage performance and endurance life. <P>SOLUTION: The electrochemical capacitor including a pair of junctures containing a metal foil collector, an electronic conductive layer, and an electronic layer and a structure having a macromolecular electrolyte film sandwiched in the junctures, includes a macromolecular binding agent where an electrode layer has a metal oxide and proton conductivity, wherein at least any of the macromolecular binding agent and the macromolecular electrolyte film is a polyarylene sulfonate containing a component unit expressed by the formulas (A) and (B), and an electron conduction layer contains a thermoplastic elastomer and electron conductive particles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel electrochemical capacitor. More specifically, the present invention relates to a novel electrochemical capacitor (especially a redox capacitor) having no corrosion, low resistance, high output density, and high reliability.

  In recent years, large-capacity capacitor technology has attracted attention as an energy storage device. As a large-capacity capacitor, an electric double layer capacitor that mainly uses an electric double layer generated at the electrode / electrolyte interface for power storage, and a metal oxide or a conductive polymer as an electrode, an oxidation-reduction reaction on the electrode surface ( There is a redox capacitor using a pseudo electric double layer capacitance), and these are often collectively referred to as an electrochemical capacitor.

  Among these, a redox capacitor using a metal oxide has a high energy density. For example, a redox capacitor using ruthenium oxide hydrate as a metal oxide and using an aqueous sulfuric acid solution as an electrolyte is known to have an energy density several times that of an electric double layer capacitor using ordinary activated carbon.

  An electrochemical capacitor using a metal oxide as an electrode can provide a large capacity. However, when a high-concentration sulfuric acid aqueous solution is used as an electrolyte, a countermeasure against corrosion is necessary. For example, in the case of a conventional electric double layer capacitor using activated carbon as an electrode and a high-concentration sulfuric acid aqueous solution as an electrolyte, a method using a composite material of rubber and conductive carbon as a current collector is widely used. Although this type of composite material is effective as a countermeasure against corrosion, it has a problem that it is difficult to obtain a large input / output density because it has higher resistance than metal and generates resistance loss during charging and discharging.

  On the other hand, in order to form a metal oxide as an electrode material as an electrode, a binder is necessary. Commonly used binders include Teflon (registered trademark), polyvinylidene fluoride, and rubber-based emulsions. However, since these materials do not have proton conductivity, they are charged and discharged as described above. It is a major factor that causes resistance loss.

  Therefore, attempts have been made to use a perfluoroalkylenesulfonic acid polymer compound having a proton conductivity (trade name: Nafion) as a binder. However, the perfluoro ionomer has a problem that the binding action of the electrode material is weak, it is easily peeled off at the interface with the metal or carbon as the current collector, and is difficult to join.

Further, as the electrolyte layer, a material that can replace the concentrated sulfuric acid aqueous solution and has high proton conductivity, good electrical connection with the electrode, and no risk of corrosion is required.
It is known that an electric double layer capacitor using a normal activated carbon has a far superior durability life and reliability as compared with a secondary battery such as a nickel-hydrogen secondary battery or a lithium ion secondary battery. The durability life and reliability are generally evaluated by a float charge test at 70 ° C.

On the other hand, the durability and reliability of redox capacitors using metal oxides are not well known, and as with secondary batteries, they have a charge / discharge process that involves mass transfer due to oxidation and reduction. Sex is a concern.
JP 2006-49866 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable electrochemical capacitor having excellent power storage performance and durable life by solving the above-mentioned problems with respect to corrosion resistance and input / output characteristics.

  In order to solve the above problems, the present inventors have intensively studied a capacitor in place of a capacitor using a sulfuric acid aqueous solution. As a result, a specific sulfonic acid group-containing polyarylene is used as an electrolyte layer in a water-containing state, the polymer is used as a binder for an electrode, and there is an electronic conductivity between the electrode layer and the metal foil current collector. It has been found that a high-capacity capacitor with excellent durability and input / output characteristics can be obtained by interposing a layer.

  That is, the electrochemical capacitor according to the present invention includes a pair of metal foil current collector, an electron conductive layer connected to the current collector, and an electrode layer connected to the current collector through the electron conductive layer. And a polymer electrolyte membrane sandwiched between a pair of joined bodies so as to be in contact with the electrode layer, wherein the electrode layer has a polymer bond having proton conductivity with a metal oxide. And sulfonation in which at least one of the polymer binder and the polymer electrolyte membrane includes a structural unit represented by the following formula (A) and a structural unit represented by the following formula (B): Polyarylene, wherein the electron conductive layer contains a thermoplastic elastomer and electron conductive particles.

In the formula (A), Y represents —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (
CF ₂ ) _i — (wherein i represents an integer of 1 to 10) and at least one structure selected from the group consisting of —C (CF ₃ ) ₂ —, Z is a direct bond, or — (CH ₂ ) _J — (j represents an integer of 1 to 10), —C (CH ₃ ) ₂ —, —O— and —S— represent at least one structure, and Ar represents —SO ₃ H, —O (CH ₂ ) _p SO ₃ H or —O (CF ₂
) _P represents an aromatic group having a substituent represented by SO ₃ H (p represents an integer of 1 to 12), m represents an integer of 0 to 10, and n represents an integer of 0 to 10. , K represents an integer of 1 to 4.

In the formula (B), A and D are each independently a direct bond, or —CO—, —SO ₂ —,
—SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i represents an integer of 1 to 10), — (CH ₂ ) _j — (j represents an integer of 1 to 10). ), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene group, —O— and —S—. 1 represents at least one structure selected from the group, B is independently an oxygen atom or a sulfur atom, R ^{1 to} R ¹⁶ may be the same or different from each other, and may be a hydrogen atom, a fluorine atom, an alkyl group, one Represents at least one atom or group selected from the group consisting of halogenated alkyl groups, allyl groups, aryl groups, nitro groups, and nitrile groups, all or part of which is halogenated, and s represents an integer of 0 to 4, t represents an integer of 0 to 4, r is Or an integer of 1 or more.

  The thickness of the electron conductive layer is preferably 1 to 30 μm. In the electron conductive layer, the thermoplastic elastomer is preferably a styrene-ethylene-butylene-styrene block copolymer, and the electron conductive particles are preferably carbon black.

  The sulfonated polyarylene preferably contains a sulfonic acid group in the range of 0.3 to 5 meq / g.

  ADVANTAGE OF THE INVENTION According to this invention, the favorable electrical storage performance excellent in corrosion resistance and an output characteristic can be shown, and the electrochemical capacitor of a high durable life can be provided.

Hereinafter, the electrochemical capacitor according to the present invention will be described in detail.
The electrochemical capacitor of the present invention includes a pair of joined bodies including a metal foil current collector, an electron conductive layer connected to the current collector, and an electrode layer connected to the current collector through the electron conductive layer And a polymer electrolyte membrane sandwiched between a pair of joined bodies so as to be in contact with the electrode layer, wherein the electrode layer has a metal oxide and a polymer binder having proton conductivity; And at least one of the polymer binder and the polymer electrolyte membrane is a specific sulfonated polyarylene described later, and the electron conductive layer includes a thermoplastic elastomer and electron conductive particles.

<Metal foil current collector>
Examples of the metal foil current collector used in the present invention include metal foils such as titanium, nickel, stainless steel, and niobium. Among these, titanium, stainless steel, and niobium are preferable from the viewpoints of cycle characteristics and stability over time, and titanium and stainless steel are particularly preferable from the viewpoint of processability to foil, cost, and the like. The thickness of the metal foil current collector is about 5 to 100 μm.

<Electron conductive layer>
The electron conductive layer used in the present invention is formed between the metal foil current collector and an electrode layer described later, and includes a thermoplastic elastomer and an electron conductive powder. By providing such an electron conductive layer, deterioration of the capacitor can be suppressed.

Examples of the thermoplastic elastomer include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), Functional group-added SEBS (f-SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), random type hydrogenated styrene-butadiene copolymer (HSBR), syndiotactic 1,2 polybutadiene ( RB), polyolefin-based thermoplastic elastomer (TPO), polyvinyl chloride-based thermoplastic elastomer (TPVC), polyurethane-based thermoplastic elastomer (TPU), polyester-based thermoplastic elastomer (TPEE), polyamide-based thermoplastic elastomer Stoma (TPA) is exemplified. The thermoplastic elastomer preferably has a glass transition point of the resin phase of 80 ° C. or higher.

  Examples of the electron conductive powder include carbon materials such as carbon black and graphite, noble metal powders such as gold and silver, or magnetic powders such as nickel and cobalt plated with noble metals.

  In order to exhibit good capacitor characteristics, the electron conductive layer needs to be formed in a thin layer of 1 μm to 30 μm. From this point of view, the electron conductive powder is preferably carbon black capable of ensuring high electron conductivity even when the particle size is small, specifically, ketjen black EC, acetylene black, Vulcan XC72, and the like. .

  In order to form a thin electron conductive layer, a thermoplastic elastomer that is soluble in a low-boiling solvent such as toluene is suitable for mixing with the electron conductive powder to form a thin layer. From such a viewpoint, a thermoplastic elastomer containing styrene is preferable. Furthermore, among thermoplastic elastomers containing styrene, it is more preferable to use SEBS, f-SEBS, SEPS, and HSBR that do not contain highly heat-stable unsaturated bonds, and SEBS is particularly preferable.

  A desirable mixing ratio of the electron conductive powder to the thermoplastic elastomer is 20 to 200 parts by weight with respect to 100 parts by weight of the elastomer. When the amount is less than 20 parts by weight, it is difficult to ensure sufficient electron conductivity. When the amount exceeds 200 parts by weight, it becomes difficult to form a thin film.

<Electrode layer>
The electrode layer used in the present invention is connected to the metal foil current collector through the electron conductive layer and includes a metal oxide and a polymer binder having proton conductivity.

As the metal oxide, any noble metal oxide and non-metal oxide can be used as long as it is a metal oxide used in a redox capacitor.
Examples of the noble metal oxide include RuO ₂ , IrO ₂ , a composite of RuO ₂ and IrO ₂ , R
a composite of uO ₂ and TiO _2, a composite of RuO ₂ and ZrO _2, a composite of RuO ₂ and Nb ₂ O ₅ , R
Examples include a composite of uO ₂ and SnO ₂ , a composite oxide of ruthenium and vanadium, a composite oxide of ruthenium and molybdenum, and a composite oxide of ruthenium and calcium.

Examples of non-noble metal oxides include NiO, WO ₃ , Co ₃ O ₄ , MoO ₃ , TiO ₂ , and Fe ₃ O ₄ .
The metal oxide may be a hydrate. _{Specifically, RuO 2 · nH 2 O,} (Ru + Ir) O X · nH 2 O, Ru (1-y) Cr y O 2 · nH 2 O, MnO 2 · nH 2 O, V 2 O 5 · nH ₂ O, NiO.nH ₂ O and the like can be mentioned.

Among the above metal oxides, a non-crystalline hydrated metal oxide system is preferable because a high capacity can be obtained. In particular, non-crystalline RuO ₂ .nH ₂ O and (Ru + Ir) O _x .nH ₂ O are used. preferable.
The metal oxide is usually in the form of particles, preferably 0.01 to 5 μm. In order to enhance the electronic conductivity of the metal oxide, a conductivity imparting agent such as carbon black or graphite may be added at the same time.

  Examples of the polymer binder having proton conductivity include a structural unit having a sulfonic acid group represented by the following formula (A) (hereinafter also referred to as “structural unit (A)” or “sulfonic acid unit”). And a structural unit having no sulfonic acid group represented by the following formula (B) (hereinafter also referred to as “structural unit (B)” or “hydrophobic unit”). Sulfonated polyarylene is preferred.

In the above formula (A), Y represents —CO—, —SO ₂ —, —SO—, —CONH—, —COO—,
_{- (CF 2) i - (} i is an integer from 1 to 10.) And -C (CF _{3) 2} - exhibits at least one structure selected from the group consisting of. Of these, —CO— and —SO ₂ — are preferable.

Z is a direct bond, or — (CH ₂ ) _j — (j represents an integer of 1 to 10), —C (CH ₃
) Shows at least one structure selected from the group consisting of _2- , -O- and -S-. Among these, a direct bond and —O— are preferable.

Ar is an aromatic having a substituent represented by —SO ₃ H, —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H (p represents an integer of 1 to 12). Indicates a group. Examples of the aromatic group include a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group, and a phenyl group and a naphthyl group are preferable. Ar represents —SO ₃ H, —O (CH ₂ ) _p SO ₃ H or —O (
It is necessary to have at least one substituent represented by CF ₂ ) _p SO ₃ H, and in the case of a naphthyl group, it is preferable to have two or more.

m is an integer of 0 to 10, preferably 0 to 2, n is an integer of 0 to 10, preferably 0 to 2, and k is an integer of 1 to 4.
As a preferred structure of the structural unit (A), in the above formula (A),
(1) a structure in which m = 0, n = 0, Y is —CO—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(2) a structure in which m = 1, n = 0, Y is —CO—, Z is —O—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(3) A structure in which m = 1, n = 1, k = 1, Y is —CO—, Z is —O—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(4) m = 1, n = 0, Y is —CO—, and Ar is two substituents —SO _3.
A structure which is a naphthyl group having H,
(5) m = 1, n = 0, Y is —CO—, Z is —O—, and Ar is a phenyl group having —O (CH ₂ ) ₄ SO ₃ H as a substituent. Examples include structures.

In the above formula (B), A and D are each independently a direct bond, or —CO—, —SO _2.
-, - SO -, - CONH -, - COO -, - (CF 2) i -, (i is an integer from 1 to 10.) - a (j is an integer of from 1 to 10 - (CH _{2) j} -CR ' _2- (R' represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene group, -O- and -S- At least one structure selected from the group consisting of Among these, a direct bond, —CO—, —SO ₂ —, —CR ′ ₂ —, a cyclohexylidene group, a fluorenylidene group, and —O— are preferable. R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group. For example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, A propyl group, an octyl group, a decyl group, an octadecyl group, a phenyl group, a trifluoromethyl group, etc. are mentioned.

B is independently an oxygen atom or a sulfur atom, preferably an oxygen atom.
R ^{1 to} R ¹⁶ may be the same as or different from each other, and are a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group partially or wholly halogenated, an allyl group, an aryl group, a nitro group, and a nitrile group. At least one atom or group selected from the group consisting of

Examples of the alkyl group in R ^{1 to} R ¹⁶ include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, and an octyl group. Examples of the halogenated alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group. Examples of the allyl group include a propenyl group. Examples of the aryl group include a phenyl group and a pentafluorophenyl group.

s represents an integer of 0 to 4, and t represents an integer of 0 to 4. r shows 0 or an integer greater than or equal to 1, and an upper limit is 100 normally, Preferably it is 1-80.
As a preferred structure of the structural unit (B), in the above formula (B),
(1) s = 1, t = 1, A is —CR ′ ₂ —, a cyclohexylidene group or a fluorenylidene group, B is an oxygen atom, and D is —CO— or —SO ₂ —. , R ^{1 to} R ¹⁶ are hydrogen atoms or fluorine atoms,
(2) a structure in which s = 1, t = 0, B is an oxygen atom, D is —CO— or —SO ₂ —, and R ^{1 to} R ¹⁶ are hydrogen atoms or fluorine atoms,
(3) s = 0, t = 1, A is —CR ′ ₂ —, a cyclohexylidene group or a fluorenylidene group, B is an oxygen atom, and R ^{1 to} R ¹⁶ are a hydrogen atom, a fluorine atom, or a nitrile group. The structure etc. which are are mentioned.

In the above formula (C), A, B, D, Y, Z, Ar, k, m, n, r, s, t and R ^{1 to} R ¹⁶ are respectively in the above formulas (A) and (B). As defined. x and y are x +
The molar ratio when y = 100 mol% is shown.

  The sulfonated sulfonated polyarylene contains the structural unit (A) in a proportion of 0.5 to 100 mol%, preferably 10 to 99.999 mol%, and contains 99.5 to 0 mol of the structural unit (B). %, Preferably 90 to 0.001 mol%.

Examples of the method for producing the sulfonated polyarylene include the following methods A, B, and C.
(Method A) For example, in the method described in JP-A No. 2004-137444, a monomer having a sulfonate group that can be the structural unit (A) and a monomer or oligomer that can be the structural unit (B) are combined. A method of polymerizing to produce a polyarylene having a sulfonic acid ester group, deesterifying the sulfonic acid ester group, and converting the sulfonic acid ester group into a sulfonic acid group.

  (Method B) For example, in the method described in JP-A-2001-342241, a monomer having a skeleton represented by the above formula (A) but having neither a sulfonic acid group nor a sulfonic acid ester group; A method in which a monomer or an oligomer that can be the structural unit (B) is copolymerized, and the resulting copolymer is sulfonated using a sulfonating agent.

(Method C) When Ar in the above formula (A) is an aromatic group having a substituent represented by —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H Is, for example, copolymerized a precursor monomer that can be the structural unit (A) and a monomer or oligomer that can be the structural unit (B) by the method described in JP-A-2005-60625, A method of introducing an alkyl sulfonic acid or a fluorine-substituted alkyl sulfonic acid.

  Examples of the monomer having a sulfonate group that can be the structural unit (A) that can be used in the method A include, for example, JP-A Nos. 2004-137444, 2004-345997, and 2004-346163. Examples thereof include sulfonic acid esters described in Japanese Patent Publication No. Gazette.

  Examples of the monomer that can be used in the above-mentioned method B and has neither a sulfonic acid group or a sulfonic acid ester group that can be the structural unit (B) include, for example, JP-A Nos. 2001-342241 and 2002-293889. Mention may be made of the dihalides described in the publication.

  Examples of the precursor monomer that can be the structural unit (A) that can be used in the method C include dihalides described in JP-A-2005-36125.

  Specific examples of the sulfonic acid ester used in the method A include the following compounds.

  Moreover, the following compounds are mentioned as a specific example of the compound which does not have any of the sulfonic acid group and sulfonic acid ester group which are used by the said B method.

Moreover, as a monomer or oligomer that can be the structural unit (B) used in any method,
When r = 0, for example, 4,4′-dichlorobenzophenone, 4,4′-dichlorobenzanilide, 2,2-bis (4-chlorophenyl) difluoromethane, 2,2-bis (4-chlorophenyl) -1 , 1,1,3,3,3-hexafluoropropane, 4-chlorobenzoic acid-4-chlorophenyl ester, bis (4-chlorophenyl) sulfoxide, bis (4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile, etc. Is mentioned. Among these compounds, compounds in which a chlorine atom is replaced with a bromine atom or an iodine atom can also be used.

In the case of r = 1, for example, compounds described in JP-A-2003-113136 can be exemplified.
In the case of r ≧ 2, for example, JP 2004-137444 A, JP 2004-244517 A, JP 2004-346164 A, JP 2005-112985 A, JP 2006-28414 A, JP The compounds described in 2006-28415 can be mentioned.

  Examples of the monomer or oligomer that can be the structural unit (B) include compounds represented by the following formulas.

In order to obtain a polyarylene having a sulfonic acid group, first, a monomer that can be the structural unit (A) and a monomer or oligomer that can be the structural unit (B) are copolymerized in the presence of a catalyst, It is necessary to obtain arylene. The catalyst used in this case is a catalyst system containing a transition metal compound, and as such a catalyst system, (i) a compound that becomes a transition metal salt and a ligand (hereinafter referred to as “ligand component”), Alternatively, a transition metal complex coordinated with a ligand (including a copper salt) and (ii) a reducing agent may be essential components, and a “salt” may be added to increase the polymerization rate. For example, the conditions described in JP-A-2001-342241 can be adopted as specific examples of these catalyst components, the use ratio of each component, the reaction solvent, concentration, temperature, time, and other polymerization conditions.

  The sulfonated polyarylene used in the present invention can be obtained by converting the precursor polyarylene obtained as described above into a polyarylene having a sulfonic acid group. As this method, there are the following three methods.

(Method a) A method of deesterifying the precursor polyarylene having a sulfonate group obtained by Method A by the method described in JP-A-2004-137444.
(Method b) A method of sulfonating the precursor polyarylene obtained in Method B by the method described in JP-A-2001-342241.

(Method c) A method of introducing an alkylsulfonic acid group into the precursor polyarylene obtained by the method C by the method described in JP-A-2005-60625.
The sulfonated polyarylene represented by the above formula (C) produced by the method as described above generally has a sulfonic acid group of 0.3 to 5 meq / g, preferably 0.5 to 3 meq / g, More preferably, it contains in the range of 0.8-2.8 meq / g. When the amount of sulfonic acid group (ion exchange capacity) is lower than the above range, proton conductivity tends to be low and output characteristics tend to be lowered. On the other hand, if the amount of the sulfonic acid group exceeds the above range, the water resistance may be significantly lowered.

  The amount of the sulfonic acid group can be adjusted, for example, by changing the type, use ratio, and combination of the precursor monomer that can be the structural unit (A) and the monomer or oligomer that can be the structural unit (B). it can.

  The molecular weight of the sulfonated polyarylene obtained as described above is 10,000 to 1,000,000, preferably 10,000 to 800,000, more preferably 20,000 to the polystyrene-reduced weight average molecular weight by gel permeation chromatography (GPC). 200,000.

  By using the sulfonated polyarylene as the polymer binder having proton conductivity, the exchange reaction of hydrogen ions at the interface between the electrode and the electrolyte proceeds smoothly, and good power storage characteristics are obtained.

  In addition, the polymer binder used in the present invention can ensure good binding between the electrode particles even if the addition amount to the electrode material is small, and good proton conductivity and electron conductivity can be obtained. Therefore, good charge / discharge performance with high energy density can be obtained.

Furthermore, the use of the polymer binder can ensure good adhesion to the metal foil serving as the current collector, so that the resistance loss at the current collector-electrode interface can be minimized.
The amount of the polymer binder contained in the electrode is desirably 2.5 to 50 parts by weight, preferably 5 to 25 parts by weight with respect to 100 parts by weight of the metal oxide. If it is less than the lower limit of the above range, the adhesiveness with the metal foil current collector may be reduced, and if it exceeds the upper limit, the electron conductivity between the electrode particles is reduced, which may cause deterioration of charge / discharge characteristics. .

<Joint>
The electrode-electron conductive layer-current collector assembly in the present invention can be produced as follows. First, the above-mentioned thermoplastic elastomer and electron conductive particles are dispersed or dissolved in a volatile solvent to form a paste, which is applied to a surface of a highly peelable substrate such as a polyester film and dried. Form a layer. Next, an electrode layer is formed by applying and drying a paste obtained by dispersing or dissolving the polymer binder and metal oxide particles in a volatile solvent on the obtained electron conductive layer. Thereafter, the base material is peeled off, and the metal foil current collector is superposed on the metal foil current collector so that the electron transmission layer is in contact with it, whereby an electrode-electron conductive layer-current collector assembly is obtained.

In the above method, it is necessary to select a solvent so that the electrode conductive paste does not dissolve the electron conductive layer which is the base layer during coating.
Also, the electrode-electron conductive layer-current collector assembly is obtained by directly applying and drying the electron conductive layer paste on the surface of the metal foil current collector, and then applying the electrode paste and drying. It can also be produced.

The obtained electrode-electron conductive layer-current collector assembly may be further subjected to a treatment such as hot roll rolling to compress the electrode.
<Polymer electrolyte membrane>
The polymer electrolyte membrane used in the present invention preferably contains a sulfonated polyarylene that can be suitably used as the polymer binder. The polymer electrolyte membrane is produced by, for example, a method (casting method) in which the sulfonated polymer is dissolved in a solvent, an additive is added as necessary, and then cast on a substrate to form a film. can do.

  The substrate is not particularly limited as long as it is a substrate used in a usual solution casting method. For example, a substrate made of plastic or metal is used, and preferably a thermoplastic resin such as a polyethylene terephthalate (PET) film. A substrate made of is used.

  Examples of the solvent include non-protons such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide, dimethylsulfoxide, dimethylurea, and dimethylimidazolidinone (DMI). Examples thereof include N-methyl-2-pyrrolidone, particularly from the viewpoint of solubility and solution viscosity. The said solvent may be used individually by 1 type, or may be used in combination of 2 or more type.

  Further, as a solvent for dissolving the sulfonated polyarylene, a mixture of the above aprotic polar solvent and alcohol may be used. Specific examples of the alcohol include methanol, ethanol, propyl alcohol, iso-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, etc. Methanol is particularly preferable because it has an effect of reducing the solution viscosity in a wide composition range. . Alcohol may be used individually by 1 type, or may be used in combination of 2 or more type.

  When preparing the polymer electrolyte membrane, in addition to the polymer compound containing the acidic ion conductive component, the above solvent, inorganic acid such as sulfuric acid and phosphoric acid, organic acid including carboxylic acid, appropriate amount of water, etc. May be used in combination.

  Moreover, when preparing a polymer electrolyte membrane, in addition to the polymer compound containing an acidic ion conductive component, the solvent and the organic acid, it interacts with the acidic ion conductive component (sulfonic acid group) in the polymer. You may use an additive together. Additives added to the solution containing the sulfonated polyarylene are selected from organic or inorganic compounds that are capable of acid-base interaction, ie, salt formation, with respect to the sulfonated polyarylene and are soluble in water or polar solvents. .

Alternatively, the polymer electrolyte membrane may be formed by dissolving sulfonated polyarylene in a solvent and directly applying the resulting solution to the electrode surface and drying.
The film thickness of the polymer electrolyte membrane is appropriately selected depending on the capacity, size, output, etc. of the capacitor, but is usually about 15 to 150 μm.

<Electrochemical capacitor>
The electrochemical capacitor of the present invention can be obtained as follows. First, the polymer electrolyte membrane is sandwiched between a pair of electrode-electron conductive layer-current collector assembly, and the membrane-electrode-electron is joined by joining the electrolyte membrane and the electrode interface by hot pressing or hot rolling. A conductive layer-current collector structure is formed. Next, the obtained membrane-electrode-electron conductive layer-current collector structure is immersed in water to contain water, and then accommodated in a predetermined capacitor can. Thereby, it can be used as an electrochemical capacitor. If necessary, the structure may be a laminate of two or more layers, or the structure may be wound and accommodated. If two or more layers are laminated or a wound body is used, the capacity can be increased. Moreover, when it is set as a laminated body, you may make it the structure which shares an adjacent collector and forms an electrode on the front and back of one collector.

  The electrochemical capacitor of the present invention can also be obtained as follows. First, a paste for an electron conductive layer is applied and dried on a base material that is easily peeled off, such as a polyester film, and an electrode-electron is applied by applying an electrode paste on the obtained electron conductive layer and drying. A two-layer body of conductive layers is formed. Next, after peeling off the two-layer body from the base material, the polymer electrolyte membrane is sandwiched between the two-layer body of a pair of electrodes-electron conductive layer, and the electron conductive layer-electrode-membrane-electrode is formed by hot pressing or hot rolling. -Prepare the structure of the electron conductive layer in advance. Thereafter, the structure and the current collector are alternately laminated by hot pressing or the like to obtain an electrochemical capacitor having a desired number of layers.

  In addition, when the above structure is formed, the electrolyte membrane or the electrode-current collector assembly is preliminarily hydrated, and then the electrolyte membrane and the electrode interface are joined by hot pressing or the like to form the membrane-electrode-current collector. The structure may be formed.

As described above, both the polymer binder and the polymer electrolyte membrane may contain the sulfonated polyarylene, or may be contained in one of them.
Next, the electrochemical capacitor according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing a configuration example of a membrane-electrode-electron conductor layer-current collector structure used in an electrochemical capacitor.

  The electrochemical capacitor of the present invention has, for example, a structure composed of a film, an electrode, an electron conductor layer, and a current collector configured as shown in FIG. The membrane-electrode-electron conductor layer-current collector structure has a polymer electrolyte membrane 3 between the positive electrode 1 and the negative electrode 2, and each of the positive electrode 1 and the negative electrode 2 has a current collector layer 4. And an electron conductive layer 6 and an electrode layer 5 formed on the current collector layer 4 and in contact with the polymer electrolyte membrane 3 on the electrode layer 5 side.

  The polymer electrolyte membrane 3 includes the sulfonated polyarylene described above, the electrode layer 5 includes the above-described metal oxide and a proton conductive polymer as a binder, and the electron conductive layer 6 includes the above-described electron conductive particles and heat. Contains plastic elastomer.

  The current collector layer 4 is made of a metal foil. As described above, the electrode layer 5 and the current collector 4 are bonded to each other by providing an electron conductive layer 6 of an electrode paste in which a metal oxide powder and a proton conductive polymer serving as a binder are uniformly mixed. The electrode layer 5 formed by coating the current collector 4 directly to form the electrode layer 5 or by applying an electrode paste on a substrate such as a polyester film provided with the electron conductive layer 6. And the metal foil current collector 4 can be performed by hot pressing.

Then, the polymer electrolyte membrane 3 is heated and pressed in a state of being sandwiched between the positive electrode 1 and the negative electrode 2 which are electrode-electron conductive layer-current collector assemblies, and the electrode-electrolyte membrane interface is joined. A structure of an electrode, an electron conductive layer, and a current collector is formed. After the structure is water-containing, it is set in a sealing can 8 that is an outer case, and is fixed by a wave spring 9 and sealed as necessary to form an electrochemical capacitor.

  As the material of the sealing can, SUS can be used from the viewpoint of preventing corrosion by sulfuric acid. In addition to the button shape shown in FIG. 1, the outer case can adopt various shapes such as a cylindrical shape and a square shape depending on the shape of the capacitor.

[Example]
EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples. In the following examples and the like, the sulfonic acid equivalent, molecular weight and proton conductivity were determined as follows.

1. Measurement of Molecular Weight The molecular weight of polyarylene having no sulfonic acid group was determined by GPC using polystyrene (THF) as a solvent and the molecular weight in terms of polystyrene. The molecular weight of polyarylene having a sulfonic acid group was determined by GPC using polystyrene as a molecular weight using N-methyl-2-pyrrolidone (NMP) to which lithium bromide and phosphoric acid were added as an eluent.

2. Sulfonic acid equivalent The obtained polymer having a sulfonic acid group was thoroughly washed until the washing water became neutral to remove free remaining acid and dried. Next, a predetermined amount of polymer was weighed, and titration was performed using a standard solution of NaOH using phenolphthalein dissolved in a THF / water mixed solvent as an indicator, and the sulfonic acid equivalent was determined from the neutralization point.

3. Measurement of proton conductivity AC resistance is measured by pressing a platinum wire (diameter 0.5 mm) against the surface of a strip-shaped polymer electrolyte membrane sample with a width of 5 mm, holding the sample in a constant temperature and humidity device, and between the platinum wires It was obtained from AC impedance measurement. As specific conditions, impedance at AC 10 kHz was measured in an environment of 25 ° C. and relative humidity 100%. A chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. was used as the resistance measurement device, and JW241 manufactured by Yamato Scientific Co., Ltd. was used as the temperature and humidity control device. Five platinum wires were pressed at intervals of 5 mm, and the AC resistance was measured while changing the distance between the wires to 5 to 20 mm. As shown in the following formula, the specific resistance of the film was calculated from the distance between lines and the gradient of resistance.

Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)
AC impedance was calculated from the reciprocal of this specific resistance, and proton conductivity was calculated from this impedance.

<Synthesis Example 1>
To a 1 L three-necked flask equipped with a stirrer, thermometer, cooling pipe, Dean-Stark pipe and nitrogen-introduced three-way cock, 2,2-bis (4-hydroxyphenyl) -1,1,1,3 , 3,3-hexafluoropropane (bisphenol AF) 67.3 g (0.20 mol), 4,4′-dichlorobenzophenone (4,4′-DCBP) 60.3 g (0.24 mol), potassium carbonate 71 .9 g (0.52 mol), N, N-dimethylacetamide (DMAc) 300 mL, and toluene 150 mL were taken, heated in an oil bath under a nitrogen atmosphere, and reacted at 130 ° C. with stirring. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was observed in about 3 hours. Most of the toluene was removed while the reaction temperature was gradually increased from 130 to 150 ° C., and the reaction was continued at 150 ° C. for 10 hours, and then 10.0 g of 4,4′-DCBP (0
. 040 mol) was added and the reaction was allowed to proceed for a further 5 hours. The resulting reaction solution was allowed to cool, and then the by-product inorganic compound precipitate was removed by filtration, and the filtrate was put into 4 L of methanol. The precipitated product was filtered and dried, and then dissolved in 300 mL of tetrahydrofuran. This was reprecipitated with 4 L of methanol to obtain 95 g (yield 85%) of the target compound.

  The number average molecular weight (Mn) in terms of polystyrene determined by GPC (THF solvent) of the obtained compound was 11,200. The obtained compound was soluble in THF, NMP, DMAc, sulfolane and the like, and had a glass transition temperature (Tg) of 110 ° C. and a thermal decomposition temperature of 498 ° C. It was confirmed that the obtained compound was an oligomer represented by the following formula (I) (hereinafter also referred to as “BCPAF oligomer”).

<Synthesis Example 2>
In a 500 mL three-necked flask equipped with a stirrer, thermometer, condenser, Dean-Stark tube and nitrogen-introduced three-way cock, 4- [4- (2,5-dichlorobenzoyl) phenoxy] benzenesulfonic acid neo -39.58 g (98.64 mmol) of pentyl (A-SO ₃ neo-Pe), 15.23 g (0.136 mmol) of the BCPAF oligomer (Mn = 11,200) obtained in Synthesis Example 1, Ni (PPh ₃ ) 1.67 g (0.26 mmol) of ₂ Cl ₂ , 10.49 g (4.00 mmol) of PPh ₃ , 0.45 g of NaI (0.3
0 mmol), 15.69 g (24.0 mmol) zinc dust and 129 mL dry NMP were added under nitrogen. The reaction system was heated with stirring (finally heated to 75 ° C.) and allowed to react for 3 hours. The polymerization reaction solution was diluted with 250 mL of THF, stirred for 30 minutes, filtered using Celite as a filter aid, and the filtrate was poured into a large excess of 1500 mL of methanol to coagulate. The coagulated product was collected by filtration, air-dried, further redissolved in THF / NMP (200/300 mL each), and coagulated with 1500 mL of a large excess of methanol. After air drying, 47.0 g (yield 92%) of a copolymer (PolyAB-SO ₃ neo-Pe) composed of a sulfonic acid derivative protected with a target yellow fibrous neopentyl group was obtained by heat drying. The molecular weight by GPC was 47,600 for Mn (number average molecular weight) and 159,000 for Mw.

The obtained PolyAB-SO ₃ neo-Pe (5.1 g) was dissolved in NMP (60 mL).
Warmed to ° C. To the reaction system, a mixture of 50 mL of methanol and 8 mL of concentrated hydrochloric acid was added at a time to form a suspension, and the mixture was reacted for 10 hours under mild reflux conditions. A distillation apparatus was installed, and excess methanol was distilled off to obtain a light green transparent solution. This solution was poured into a large amount of water / methanol (1: 1 weight ratio) to solidify the polymer, and then the polymer was washed with ion-exchanged water until the pH of the washing water became 6 or more. From quantitative analysis of the IR spectrum and ion exchange capacity of the polymer thus obtained, the sulfonate group (—SO ₃ R) was quantitatively determined to be a sulfonate group (—S
O ₃ H) was found to be converted.

The molecular weight of the obtained sulfonated polymer by GPC is 53,200 for Mn and 1 for Mw.
And the sulfonic acid equivalent weight was 2.2 meq / g.
<Synthesis Example 3>
To a 1 L three-necked flask equipped with a stirrer, thermometer, Dean-Stark tube, nitrogen inlet tube and condenser tube was added 48.8 g (284 mmol) of 2,6-dichlorobenzonitrile and 2,2-bis (4-hydroxyphenyl). -1,1,1,3,3,3-Hexafluoropropane 89.5 g (266 mmol) and potassium carbonate 47.8 g (346 mmol) were weighed. After substitution with nitrogen, 346 mL of sulfolane and 173 mL of toluene were added and stirred, and the reaction solution was heated to reflux at 150 ° C. in an oil bath. Water produced by the reaction was trapped in a Dean-Stark tube. After 3 hours, when almost no water was observed, toluene was removed from the Dean-Stark tube out of the system. The reaction temperature was gradually raised to 200 ° C. and stirring was continued for 3 hours. Then, 9.2 g (53 mmol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 5 hours.

The reaction solution was allowed to cool, and diluted with 100 mL of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 L of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 mL of tetrahydrofuran, and poured into 2 L of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 109 g of the objective compound. Mn of the obtained compound measured by GPC was 9,500. It was confirmed that the obtained compound was an oligomer represented by the following formula (II).

<Synthesis Example 4>
In a 1 L three-necked flask equipped with a stirrer, a thermometer and a nitrogen introducing tube, 135.2 g (337 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, oligomer of Mn 9,500 obtained in Synthesis Example 3 48.7 g (5.1 mmol), bis (triphenylphosphine) nickel dichloride 6.71 g (10.3 mmol), sodium iodide 1.54 g (10.3 mmol), triphenylphosphine 35.9 g (137 mmol) and zinc 53 0.7 g (821 mmol) was weighed and replaced with dry nitrogen. 430 mL of N, N-dimethylacetamide (DMAc) was added thereto, and the reaction temperature was adjusted to 8
Stirring was continued for 3 hours while maintaining the temperature at 0 ° C., and then DMAc 730 mL was added for dilution, and insoluble matters were filtered.

The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube. The mixture was heated and stirred at 115 ° C., and 44 g (506 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 5 L of acetone. Next, after washing with 1N hydrochloric acid and pure water in this order, drying was performed to obtain 122 g of the target polymer. The weight average molecular weight (Mw) of the obtained polymer was 135,000. The obtained polymer is presumed to be a sulfonated polymer represented by the following formula (III).

<Synthesis Example 5>
In a 1 L three-necked flask equipped with a stirrer, a thermometer and a nitrogen introduction tube, 135.2 g (337 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, hydrophobicity of Mn 9,500 obtained in Synthesis Example 3 Sex unit 48.7 g (5.1 mmol), 4-chlorobenzophenone 1.5 g (6.9 mmol), bis (triphenylphosphine) nickel dichloride 6.71 g (10.3 mmol), sodium iodide 1.54 g (10. 3 mmol), 35.9 g (137 mmol) of triphenylphosphine and 53.7 g (821 mmol) of zinc were weighed and purged with dry nitrogen. 430 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 730 mL of DMAc was added for dilution, and insoluble matters were filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer and a nitrogen inlet tube. The mixture was heated and stirred at 115 ° C., and 44 g (506 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 5 L of acetone. Next, after washing with 1N hydrochloric acid and pure water in this order, drying was performed to obtain 122 g of the target polymer. The weight average molecular weight (Mw) of the obtained polymer was 80,000. The obtained polymer is presumed to be a sulfonated polymer represented by the following formula (IV).

[Example 1]
The sulfonated polyarylene obtained in Synthesis Example 2 was dissolved in N-methyl-2-pyrrolidone, and a polymer electrolyte membrane having a dry film thickness of 40 μm was prepared by a casting method. The proton conductivity of the obtained polymer electrolyte membrane was measured at 25 ° C. and 100% RH to find 4.0 × 10 ⁻¹ S /
cm.

  Next, ruthenium dioxide hydrate (manufactured by Aldrich) particles, acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.), and the sulfonated polyarylene obtained in Synthesis Example 2 are dissolved in N-methyl-2-pyrrolidone. An ion conductive polymer binder was uniformly mixed at a weight ratio of particles: acetylene black: binder = 1: 0.05: 0.15 to prepare an electrode paste.

  Next, a styrene-ethylene-butylene-styrene block copolymer (SEBS, trade name KRATON G1652, manufactured by Kraton Co., Ltd.) is dissolved in toluene, and this and Ketjen Black EC (manufactured by Lion Corporation) are combined with SEBS: Ketjen. An electron conductive layer paste was prepared by uniformly mixing to a weight ratio of black EC = 1: 0.5.

Next, the electron conductive layer paste is coated on a 30 μm thick titanium foil with a blade coater so that the thickness after coating and drying is 5 μm, and dried at 120 ° C. for 10 minutes to form an electron conductive layer. Was formed on a titanium foil. Thereafter, the electrode paste was coated on the electron conductive layer with a blade coater so that the amount of ruthenium dioxide hydrate was 5 mg / cm ² , dried at 60 ° C. for 10 minutes, and then dried at 100 ° C. under reduced pressure. Then, an electrode-electron conductive layer-current collector assembly including a ruthenium dioxide hydrate layer was formed.

  Next, the polymer electrolyte membrane was punched out to a diameter of 14 mm, and immersed in pure water at 50 ° C. for 30 minutes to contain water. Similarly, the electrode-electron conductive layer-current collector assembly was punched to a diameter of 12 mm for the positive electrode and the negative electrode, respectively, and immersed in pure water at 25 ° C. for 30 minutes to be hydrated.

These were treated with water, and then wrapped in a Teflon (registered trademark) film with the polymer electrolyte membrane sandwiched between the positive electrode and negative electrode-electron conductive layer-current collector assembly, and 160 ° C., 10 kg / c.
Pressure was applied for 5 minutes under m ² pressing conditions to obtain a structure in which the electrolyte membrane-electrode interface was bonded. The obtained structure was immersed in pure water at 25 ° C. for 15 minutes for water treatment. After the water-containing treatment, excess water on the surface of the structure was removed, and the structure was set in a SUS sealing can as shown in FIG. 1 and sealed with a caulking device to form an electrochemical capacitor.

The following impedance evaluation was performed as the performance of the electrochemical capacitor.
Using a chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. as an impedance measurement device, an impedance of 1 Hz to 20 kHz was measured at a measurement voltage of 10 mV, and a DC component of an impedance of 1 kHz was obtained as the impedance of the capacitor. The results are shown in Table 1.

In addition, in order to obtain the initial output performance of the capacitor, “Model” manufactured by Power System Co., Ltd.
CDT5R2-4 "and charge / discharge currents of ² mA / cm ² , 5 mA / cm ² , 10 mA / cm ² , 20 mA / cm ² , 50 mA / cm ² , 100 mA / cm ² and 200 mA / cm ² , respectively. Charging / discharging at 0-1 V was performed. Charging is performed for a fixed time ( ² mA / cm ² ; 1500 seconds, 5 mA / cm ² ; 600 seconds, 10 mA / cm ² ; 300 seconds, 20 mA / cm ² ; 150 seconds, 50 mA / cm ² ; 60 seconds, 100 mA / cm ² 30 seconds, 200 mA / cm ² ; 20 seconds), and discharging was performed at a constant current to evaluate discharge capacity and discharge output. The results are shown in Table 2.

  The discharge capacity was determined by the energy conversion method, and the discharge output was also calculated from this value. The unit weight of discharge capacity (F / g) and discharge output (W / kg) is divided by the weight of positive and negative electrode materials (hydrated ruthenium oxide). In particular, the discharge capacity may be expressed as the capacity per unit weight, but in this case, the value is four times.

  Subsequently, in order to evaluate reliability, evaluation by float charging at 70 ° C. was performed. In an environment of 70 ° C., a voltage of 0.70 V is continuously applied, and after 1000 hours of voltage application, the output performance is evaluated at room temperature in the same manner as the initial output performance described above. The degree of deterioration was evaluated. The results are shown in Table 2.

[Example 2]
First, the sulfonated polyarylene obtained in Synthesis Example 4 was dissolved in N-methyl-2-pyrrolidone, and a polymer electrolyte membrane having a dry film thickness of 40 μm was prepared by a casting method.

Next, ruthenium dioxide hydrate (manufactured by Aldrich) particles and an ion conductive polymer binder obtained by dissolving the sulfonated polyarylene obtained in Synthesis Example 5 in N-methyl-2-pyrrolidone, particles: An electrode paste was prepared by uniformly mixing the binder at a weight ratio of 1: 0.025.

  Next, a styrene-ethylene-butylene-styrene block copolymer (SEBS, trade name KRATON G1652, manufactured by Kraton Co., Ltd.) is dissolved in toluene, and this and Ketjen Black EC are SEBS: Ketjen Black EC = 1. An electron conductive layer paste was prepared by uniformly mixing to a weight ratio of 0.5.

Next, the electron conductive layer paste is coated on a 30 μm thick titanium foil with a blade coater so that the thickness after coating and drying is 5 μm, and dried at 120 ° C. for 10 minutes to form an electron conductive layer. Was formed on a titanium foil. Thereafter, the electrode paste was coated on the electron conductive layer with a blade coater so that the amount of ruthenium dioxide hydrate was 5 mg / cm ² , dried at 60 ° C. for 10 minutes, and then dried at 100 ° C. under reduced pressure. Then, an electrode-electron conductive layer-current collector assembly including a ruthenium dioxide hydrate layer was formed.

  Next, the polymer electrolyte membrane was punched out to a diameter of 14 mm, and immersed in pure water at 50 ° C. for 30 minutes to contain water. Similarly, the electrode-current collector assembly was punched to a diameter of 12 mm for the positive electrode and the negative electrode, respectively, and immersed in pure water at 25 ° C. for 30 minutes to contain water.

After these were treated with water, the polymer electrolyte membrane was sandwiched between the positive electrode and the negative electrode-electron conductive layer-current collector assembly, and wrapped in a Teflon (registered trademark) film, and 160 ° C., 10 kg / cm ² . Pressure was applied for 5 minutes under pressing conditions to obtain a structure in which the electrolyte membrane-electrode interface was bonded. The obtained structure was immersed in pure water at 25 ° C. for 15 minutes for water treatment. After the water-containing treatment, excess water on the surface of the structure was removed, and the structure was set in a SUS sealing can as shown in FIG. 1 and sealed with a caulking device to form an electrochemical capacitor. The obtained electrochemical capacitor was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Example 3
Ruthenium dioxide hydrate (manufactured by Aldrich) particles and an ion conductive polymer binder obtained by dissolving the sulfonated polyarylene obtained in Synthesis Example 5 in N-methyl-2-pyrrolidone, particles: binder = 1 : Electrode-conductive layer-current collector provided with a ruthenium dioxide hydrate layer in the same manner as in Example 2 except that the electrode paste was prepared by mixing uniformly at a weight ratio of 0.075. A joined body was formed, and then an electrochemical capacitor was fabricated and evaluated. The results are shown in Tables 1 and 2.

Example 4
Ruthenium dioxide hydrate (manufactured by Aldrich) particles and an ion conductive polymer binder obtained by dissolving the sulfonated polyarylene obtained in Synthesis Example 5 in N-methyl-2-pyrrolidone, particles: binder = 1 : Electrode-electron conducting layer-current collector junction comprising a ruthenium dioxide hydrate layer in the same manner as in Example 2 except that the electrode paste was prepared by mixing uniformly at a weight ratio of 0.15. A body was formed and then an electrochemical capacitor was made and evaluated. The results are shown in Tables 1 and 2.

Example 5
Ruthenium dioxide hydrate (manufactured by Aldrich) particles and an ion conductive polymer binder obtained by dissolving the sulfonated polyarylene obtained in Synthesis Example 5 in N-methyl-2-pyrrolidone, particles: binder = 1 : Electrode-electron conducting layer-current collector junction comprising a ruthenium dioxide hydrate layer in the same manner as in Example 2 except that the electrode paste was prepared by mixing uniformly at a weight ratio of 0.30. A body was formed and then an electrochemical capacitor was made and evaluated. The results are shown in Tables 1 and 2.

Example 6
Ruthenium dioxide hydrate (manufactured by Aldrich) particles and an ion conductive polymer binder obtained by dissolving the sulfonated polyarylene obtained in Synthesis Example 5 in N-methyl-2-pyrrolidone, particles: binder = 1 : Electrode-electron conducting layer-current collector junction comprising a ruthenium dioxide hydrate layer in the same manner as in Example 2 except that the electrode paste was prepared by mixing uniformly at a weight ratio of 0.50. A body was formed and then an electrochemical capacitor was made and evaluated. The results are shown in Tables 1 and 2.

[Comparative Example 1]
An electrochemical capacitor was constructed in the same manner as in Example 1 except that the electrode paste was directly applied and dried on the titanium foil without forming the electron conductive layer, and the same evaluation was performed. The results are shown in Tables 1 and 2.

[Comparative Example 2]
An electrochemical capacitor was constructed in the same manner as in Example 5 except that the electrode paste was directly applied and dried on the titanium foil without forming the electron conductive layer, and the same evaluation was performed. The results are shown in Tables 1 and 2.

It is explanatory sectional drawing which shows one structural example of the membrane-electrode-electron conductor layer-collector structure used for an electrochemical capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Positive electrode 2 ... Negative electrode 3 ... Polymer electrolyte membrane 4 ... Metal foil collector 5 ... Electrode layer 6 ... Electron conduction layer 8 ... Can 9 ... Waveform Spring 10 ... Gasket

Claims (4)

A pair of joined bodies including a metal foil current collector, an electron conductive layer connected to the current collector, and an electrode layer connected to the current collector through the electron conductive layer, and in contact with the electrode layer And a polymer electrolyte membrane sandwiched between a pair of joined bodies,
The electrode layer includes a metal oxide and a polymer binder having proton conductivity,
At least one of the polymer binder and the polymer electrolyte membrane is a sulfonated polyarylene containing a structural unit represented by the following formula (A) and a structural unit represented by the following formula (B):
The electrochemical capacitor, wherein the electron conductive layer includes a thermoplastic elastomer and electron conductive particles.

[In the formula (A), Y represents —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (
CF ₂ ) _i — (i represents an integer of 1 to 10) and at least one structure selected from the group consisting of —C (CF ₃ ) ₂ —,
Z is a direct bond, or at least one selected from the group consisting of — (CH ₂ ) _j — (j represents an integer of 1 to 10), —C (CH ₃ ) ₂ —, —O—, and —S—. Show the structure of the species,
Ar is an aromatic having a substituent represented by —SO ₃ H, —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H (p represents an integer of 1 to 12). Group,
m shows the integer of 0-10, n shows the integer of 0-10, k shows the integer of 1-4. ]

[In the formula (B), A and D are each independently a direct bond, or —CO—, —SO ₂ —,
—SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i represents an integer of 1 to 10), — (CH ₂ ) _j — (j represents an integer of 1 to 10). ), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene group, —O— and —S—. At least one structure selected from the group;
B is independently an oxygen atom or a sulfur atom,
R ^{1 to} R ¹⁶ may be the same as or different from each other, and are a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group partially or wholly halogenated, an allyl group, an aryl group, a nitro group, and a nitrile group. At least one atom or group selected from the group consisting of
s represents an integer of 0 to 4, t represents an integer of 0 to 4, and r represents 0 or an integer of 1 or more. ]   The electrochemical capacitor according to claim 1, wherein the electron conductive layer has a thickness of 1 to 30 μm. 2. The electrochemical capacitor according to claim 1, wherein the thermoplastic elastomer is a styrene-ethylene-butylene-styrene block copolymer, and the electron conductive particles are carbon black.   The electrochemical capacitor according to any one of claims 1 to 3, wherein the sulfonated polyarylene contains a sulfonic acid group in a range of 0.3 to 5 meq / g.

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