JP2002246066A - Electrolyte component, electrochemical cell, photo- electrochemical cell, and nonaqueous secondary cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolyte component, having superior charge transport capability and high molecular liquid crystal properties without substantially volatilizing, and to provide an electrochemical cell containing the electrolyte component and having superior durability and ionic conduction property. SOLUTION: This electrolyte component has a side chain, having a cationic part or an anionic part in a polyalkylene oxide main chain and a counter ion of the side chain, and the side chain or the counter ion contains polyalkylene oxide, having liquid crystal property. Moreover, it s preferable that the polyalkylene oxide include a structure expressed in the following formula (I), wherein A denotes a substituent having the anionic part or the cationic part, Y denotes the counter ion of A, and at least either of A and Y has liquid crystal property.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel polymer liquid crystal electrolyte composition. Further, the present invention relates to an electrochemical battery using the electrolyte composition, particularly a nonaqueous secondary battery and a photoelectrochemical battery.

[0002]

2. Description of the Related Art An electrolyte used in an electrochemical cell such as a non-aqueous secondary battery or a dye-sensitized solar cell contains a carrier ion according to the purpose, and transports the ion between electrodes (called ion conduction). ). For example, transport of lithium ions is a problem in a lithium secondary battery that is a typical nonaqueous secondary battery, and conductivity of iodine ions and iodine trimer ions is a problem in a dye-sensitized solar cell. In these batteries, generally, a solution system having high ion conductivity is often used as an electrolyte. However, there is a problem that the exhaustion or leakage of the solvent when incorporated into the battery lowers the durability of the battery. In addition, in the lithium secondary battery, a metal container must be used to seal the solution, so that the weight of the battery becomes heavy, and it is difficult to give a degree of freedom to the shape of the battery. In order to overcome such disadvantages of the solution electrolyte, various electrolytes have recently been proposed. A so-called gel electrolyte in which a solution electrolyte is impregnated into a polymer matrix (Japanese Patent Publication No. Sho 61-23945,
JP-B-61-23947) has a small decrease in ionic conductivity with respect to a solution-based electrolyte and does not lower battery performance, but cannot completely suppress volatilization of a solvent.
In addition, polymer electrolytes in which salts are dissolved in polymers such as polyethylene oxide (K. Murata, ElectrochimicaActa, Vo
l.40, No.13-14, p2177-2184, 1995) is expected to solve the problem of solution-based electrolytes, but the ionic conductivity is not yet sufficient. On the other hand, when the counter anion is BF ₄ ⁻ , (C
F ₃ SO _{2) 2} N ^- imidazolium salt or a pyridinium salt, such as a room temperature molten salt which is liquid at room temperature, as an electrolyte for lithium-ion batteries, have been proposed. However, the mechanical strength of the electrolyte is opposite to the ionic conductivity. If the mechanical strength is increased by increasing the viscosity of the molten salt itself or by incorporating a polymer, the ionic conductivity is reduced. Can be Furthermore, in the above-mentioned electrolytes, the ionic conductivity has a large temperature dependency, and the ionic conductivity at low temperatures is particularly insufficient.

By the way, photovoltaic power generation, which converts light energy into electric energy, includes monocrystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells,
Compound solar cells such as cadmium telluride and indium copper selenide have been put into practical use or subject to research and development.However, in order to spread them, problems such as manufacturing costs, securing of raw materials, and long energy payback time have been identified. It needs to be overcome. On the other hand, there have been proposed many solar cells using an organic material intended to have a large area and a low price, but have a problem that conversion efficiency is low and durability is poor.

In such a situation, Nature (No. 3)
53, pp. 737-740, 1991) and U.S. Pat. No. 4,927,721 and the like, a photoelectric conversion element using an oxide semiconductor sensitized by a dye (hereinafter, abbreviated as a dye-sensitized photoelectric conversion element) and the like. The technology of the photoelectrochemical cell used was disclosed. This battery includes a photoelectric conversion element functioning as a negative electrode, a charge transfer layer, and a counter electrode. The photoelectric conversion element includes a conductive support and a photosensitive layer, and the photosensitive layer includes a semiconductor having a surface on which a dye is adsorbed. The charge transfer layer is made of an oxidation-reduction body and performs charge transport between the negative electrode and the counter electrode (positive electrode). In the photoelectrochemical cell proposed in the above patent, an aqueous solution (electrolytic solution) using a salt such as potassium iodide as an electrolyte was used as the charge transfer layer. This method is promising in that it is inexpensive and can provide relatively high energy conversion efficiency (photoelectric conversion efficiency). However, when used for a long time, the photoelectric conversion efficiency drops significantly due to evaporation and depletion of the electrolyte, and the battery functions as a battery. There was a problem that it would not be.

[0005] In order to solve this problem, as a method for preventing depletion of the electrolytic solution, WO 95/18456 describes a method using an imidazolium salt as a low melting point compound as an electrolyte.
According to this method, water or an organic solvent, which has been conventionally used as a solvent for the electrolyte, is not necessary or is small, so that the durability has been improved, but the durability is still insufficient, and the imidazolium is still insufficient. When the concentration of the salt is increased, the viscosity is increased, the charge transporting ability is reduced, and the photoelectric conversion efficiency is reduced. Further, there is a method using a triazolium salt as an electrolyte, but this method also has the same problem as the imidazolium salt.

As described above, it is very difficult to achieve both mechanical strength and ionic conductivity as an electrolyte of an electrochemical cell such as a lithium ion secondary battery or a solar battery.

As one method for solving these problems, it has been proposed to include a liquid crystal compound in an electrolyte composition. Examples thereof include a compound having a mesogen group and a site having a coordinating ability to an ion such as an alkyleneoxy group (JP-A-11-86629), and a compound having a mesogen group introduced into a polyethylene oxide molecular chain (JP-A-Hei.
-323260), a compound having a liquid crystal moiety in the side chain of polyethylene oxide (JP-A-11-116792)
And so on. These are composed of a flexible part with high mobility that conducts ions by dissolving the electrolyte salt by complexing with cations, and a rigid part (mesogen group) for assembling molecules to maintain mechanical strength. ing.

By the way, recent research by Shigehara et al. (Jour
nal of Power Source, 92, 1
20-123, 2001), in order for an electrolyte to function efficiently in an electrochemical cell, in addition to having high ionic conductivity, ions that serve as carriers are more selectively conducted, that is, It has been found that a high carrier ion transport number is important for performance. For example, a lithium ion battery preferably has a high lithium ion transport number, and a dye sensitized solar cell having an iodine anion as a carrier preferably has a high iodine anion transport number. In the electrolyte using the liquid crystal compound described above, it is necessary to add ions according to the purpose in the form of a salt, and the conduction of the counter ion of the carrier ion lowers the transport number of the carrier ion and lowers the battery performance. .

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a polymer liquid crystal electrolyte composition which does not substantially volatilize and has excellent charge transportability, and further contains the electrolyte composition, and has excellent durability and ion conductivity. It is an object of the present invention to provide an electrochemical battery, a photoelectrochemical battery having excellent durability and photoelectric conversion characteristics, and a non-aqueous secondary battery having excellent cycle characteristics without reducing the battery capacity.

[0010]

Means for solving the above problems are as follows. That is, <1> a polyalkylene oxide having a side chain having a cation site or an anion site in the polyalkylene oxide main chain, and a counter ion of the side chain, wherein the side chain or its counter ion is liquid crystalline. It is an electrolyte composition characterized by containing. <2> The polyalkylene oxide has the following formula (I)
It is an electrolyte composition as described in said <1> containing the structure represented by these.

[0011]

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(In the formula (I), A represents a substituent having an anion moiety or a cation moiety, Y represents a counter ion of A, and at least one of A and Y is liquid crystalline.) <3> The polyalkylene oxide has the following formula (II)
The electrolyte composition according to the item <1> or <2>, comprising a structure represented by the formula:

[0013]

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(In the formula (II), R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.) <4> The above-mentioned <wherein the side chain is a liquid crystalline anion. The electrolyte composition according to any one of 1> to <3>. <5> The electrolyte composition according to any one of <1> to <3>, wherein the side chain is a liquid crystalline cation. <6> The electrolyte composition according to <4>, wherein the side chain counter ion is an alkali metal ion. <7> The side chain counter ion is an iodine anion or at least one selected from sulfonamide, disulfonimide, N-acyl sulfonamide, carboxylic acid, sulfonic acid, alcohol, active methylene, and active methine. The electrolyte composition according to <5>, wherein the electrolyte composition is a dissociated anion. <8> An electrochemical battery including the electrolyte composition according to any one of <1> to <7>. <9> A photoelectric device comprising a charge transfer layer containing the electrolyte composition according to any one of <1> to <7>, a photosensitive layer containing a semiconductor sensitized with a dye, and a counter electrode. It is a chemical battery. <10> A non-aqueous secondary battery including the electrolyte composition according to any one of <1> to <7>. In the electrolyte, it is important that only the ions to be moved do not move (the transport number of the target ion is high). When the target ion is added in the form of a salt, the conduction of the counter ion of the target ion lowers the transport number of the target ion. According to the electrolyte composition of the present invention, in a polymer having an anion site in a side chain, by setting the counter cation to, for example, lithium, the lithium ion itself becomes a lithium salt. Can be used as electrolyte, anion is bound to polymer chain (chemical bond)
Therefore, the lithium ion transport number is 1 (single ion transfer). Further, in an electrolyte such as for a dye-sensitized solar cell which wants to transport an anion, only the counter anion (for example, iodine) can be moved by fixing the cation to the side chain. As described above, by immobilizing immobilized ions in a polymer by chemical bonding, the transport number of the target ion can be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Electrolyte composition] The electrolyte composition of the present invention is prepared by using a reaction solvent such as a chemical reaction and metal plating, a CCD (Charge Coupled Device).
It can be used for cameras, various electrochemical batteries (so-called batteries), electrochemical sensors, photoelectrochemical sensors, and the like. It is preferably used for a nonaqueous secondary battery (particularly, a lithium secondary battery) and a photoelectrochemical battery using a semiconductor described later, and more preferably used for a photoelectrochemical battery.

The electrolyte composition of the present invention comprises a polyalkylene oxide main chain having a side chain having a cation site or an anion site, and a counter ion of the side chain, wherein the side chain or its counter ion has a liquid crystalline property. A polyalkylene oxide. The polyalkylene oxide has a counter ion of the side chain as a carrier ion such as a lithium ion (lithium battery system) or an iodine anion (a dye-sensitized solar cell system), thereby adding a new salt without adding a salt. Since itself can be used as the electrolyte, there is no mobile ion other than the carrier ion, and the transport number of the carrier ion can be improved. Examples of the polyalkylene oxide main chain include a polyethylene oxide main chain and a polypropylene oxide main chain. The polyalkylene oxide preferably has a structure represented by the following formula (I) in its molecular chain.

[0017]

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In the formula (I), A represents a substituent having an anion site or a cation site, Y represents a counter ion of A, and at least one of A and Y is liquid crystalline. In the present invention, it is preferable that A in the formula (I), that is, the side chain having a cation portion or an anion portion is liquid crystalline in that a counter ion thereof can be a mobile carrier ion. The polyalkylene oxide may have a substituent having two or more different anion sites or cation sites in its molecular chain.

Examples of the anion site include iodine anion, sulfonamide, disulfonimide, N-
Preferably, acyl sulfonamide, carboxylic acid, sulfonic acid, alcohol, active methylene and active methine are dissociated anions, more preferably anion of sulfonic acid, disulfonimide and N-acyl sulfonamide.

The cation moiety is represented by the following formula (III)
-A), (III-b) and (III-c) are preferred examples.

[0021]

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Q _y1 in the formula (III-a) represents an atomic group capable of forming a 5- or 6-membered aromatic cation together with a nitrogen atom, and R _y1 represents a substituted or unsubstituted alkyl group;
Represents a polymerizable group or a substituted or unsubstituted alkenyl group.

A _y1 in the formula (III-b) represents a nitrogen atom or a phosphorus atom, and R _y2 , R _y3 , R _y4 and R _y5 each independently represent a substituted or unsubstituted alkyl group or polymerizable group. ,
Or a substituted or unsubstituted alkenyl group.
Two or more of R _y2 , R _y3 , R _y4 and R _y5 may be linked to each other to form a non-aromatic ring containing A _y1 .

In the formula (III-c), R _y1 , R _y2 , R _y3 ,
R _y4 , R _y5 and R _y6 each independently represent a substituted or unsubstituted alkyl group, a polymerizable group, or a substituted or unsubstituted alkenyl group, and two or more of them are linked to each other to form a ring; A structure may be formed.

The cation represented by the formula (III-a), the formula (III-b) or the formula (III-c) is a cation represented by Q _y1 or R _y1 .
_Multimers may be formed via R _y6 .

In the formula (III-a), the aromatic 5
_{Alternatively} , the constituent atoms of the atomic group Q _y1 capable of forming a 6-membered ring cation are preferably selected from carbon, hydrogen, nitrogen, oxygen and sulfur.

The six-membered ring completed by Q _y1 is preferably pyridine, pyrimidine, pyridazine, pyrazine or triazine, more preferably pyridine.

The aromatic 5-membered ring completed by Q _y1 is preferably oxazole, thiazole, imidazole,
Pyrazole, isoxazole, thiadiazole, oxadiazole and triazole, more preferably oxazole, thiazole and imidazole. Particularly, oxazole and imidazole are preferable.

Formulas (III-a), (III-b) and (III
R _y1 to R _y6 in the -c) are each independently a substituted or unsubstituted alkyl group (preferably a number of carbon atoms (hereinafter C number)
Is 1 to 24, and may be linear, branched or cyclic, and may be, for example, methyl, ethyl, propyl, butyl, i-propyl, pentyl, hexyl, octyl , 2-ethylhexyl, t-octyl,
Decyl, dodecyl, tetradecyl, 2-hexyldecyl, octadecyl, cyclohexyl, cyclopentyl), a polymerizable group (preferably a vinyl group, an acryloyl group, a methacryloyl group, a styryl group, a cinnamic acid residue, etc.), or a substituted or unsubstituted alkenyl Represents a group (preferably having 2 to 24 carbon atoms, which may be linear or branched, for example, vinyl or allyl), preferably an alkyl group having 3 to 18 carbon atoms or a C number. 2-18
And more preferably an alkyl group having 4 to 6 carbon atoms.

Formulas (III-a), (III-b) and (III
Q _y1 and R _{y1 to} R _{y6 in} -c) may have a substituent. Examples of a preferable substituent include a halogen atom (F, Cl, Br, I), a cyano group, an alkoxy group ( Methoxy, ethoxy, butoxy, octyloxy, methoxyethoxy, methoxypenta (ethyloxy), acryloyloxyethoxy, pentafluoropropoxy, etc., aryloxy group (eg, phenoxy), alkylthio group (eg, methylthio, ethylthio), acyl group (acetyl, propionyl) , Benzoyl, etc.), sulfonyl group (methanesulfonyl, benzenesulfonyl, etc.), acyloxy group (acetoxy, benzoyloxy, etc.), sulfonyloxy group (methanesulfonyloxy, toluenesulfonyloxy, etc.), phosphonyl group (diethylphosphonyl, etc.), amide Group (acetylamino, benzoylamide, etc.), carbamoyl group (N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), alkyl group (methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, 2-carboxyethyl, benzyl, etc.) ), An aryl group (eg, phenyl, toluyl), a heterocyclic group (eg, pyridyl, imidazolyl, furanyl), an alkenyl group (eg, vinyl, 1-propenyl),
Examples thereof include an alkoxycarbonyl group (such as methoxycarbonyl and ethoxycarbonyl), and a polymerizable group (preferably a vinyl group, an acryloyl group, a methacryloyl group, a styryl group, a cinnamic acid residue, and the like).

In the above formula (I), Y is a counter ion of A, and an organic anion, an organic cation, an inorganic cation, or an inorganic anion similar to A described above is selected according to the charge of A.

When Y is an inorganic cation, preferable examples include an alkali metal ion, and a lithium ion is particularly preferable. When Y is an inorganic anion, halogen anion ^{(Cl -, Br -, I} -), iodine Motosan mer anion _{^{(I 3 -), NCS -}} , BF 4 -, PF 6 -, O 4 Cl -, (C n
_{F 2n + 1 SO 2) (} C m F 2m + 1 SO 2) N - imide represented by anions (n, m are each 6 or less positive integer), C _n
F _2n + 1 SO ₃ ^- fluoro sulfonic acid anion represented by (n is 6 or less positive ^{_{integer), Ph 4 B -, AsF}} 6 -, Sb
Preferred examples include F ₆ ⁻ , B ₁₀ Cl ₁₀ ^{− and the} like.

The pKa of the conjugate acid in the anion portion is preferably 11 or less, more preferably 7 or less.

The mesogen group contained in the liquid crystal moiety of A or Y in the above formula (I) includes "Flussige Krista"
lle in Tabellen II, Dietrich Demus and Horst Zaschk
e, 7-18 (1984). ". Among them, a compound represented by the following formula (IV) is preferable.

[0035]

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In the formula (IV), Y ₁₁₁ is a divalent 4 to 7
Represents a membered ring substituent or a fused ring substituent composed thereof. Q ₁₂₁ and Q ₁₃₁ each represent a divalent linking group or a single bond, n represents 1, 2 or 3, and when n is 2 or 3, a plurality of Y ₁₁₁ , Q ₁₂₁ and Q ₁₃₁ each represent They may be the same or different.

In the formula (IV), Q ₁₂₁ and Q ₁₃₁ each represent a divalent linking group or a single bond. Examples of the divalent linking group include -CH = CH-, -CH = N-, -N = N
-, -N (O) = N-, -COO-, -COS-, -C
_{ONH -, - COCH 2 -,} - CH 2 CH 2 -, - OCH 2
_{-, - CH 2 NH -,} - CH 2 -, - CO -, - O -, -
S-, -NH-,-(CH ₂ ) _1-3- , -CH = CH-C
OO—, —CH ＝ CH—CO—, — (C≡C) _1-3 — and a combination thereof are preferable, and —CH ₂ —, —CO
-, -O-, -CH = CH-, -CH = N-, -N = N
-And combinations thereof are more preferred. Further, those in which a hydrogen atom is substituted may be used. Q
It is particularly preferred that ₁₂₁ and Q ₁₃₁ are a single bond.

In the formula (IV), Y ₁₁₁ is a divalent 4, 5, 6
Or a 7-membered ring substituent or a condensed ring substituent composed thereof, a 6-membered aromatic group, a 4- or 6-membered saturated or unsaturated aliphatic group, a 5- or 6-membered heterocyclic group, Further, a condensed ring thereof is more preferable, and examples of these include, but are not limited to, substituents of the following formulas (Y-1) to (Y-27). Also, a combination of these may be used. Among these substituents, more preferred are (Y-1), (Y-2) and (Y-1).
8), (Y-19), (Y-21) and (Y-22), and particularly preferable ones are (Y-1), (Y-2),
(Y-21).

[0039]

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[0040]

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It is preferable that any one of A and Y in the formula (I) contains an alkyl group, an alkenyl group, an alkylene group, or an alkenylene group. The alkyl group or alkenyl group preferably has 6 to 25 carbon atoms, more preferably 6 to 18 carbon atoms. Further, the compound may have a substituent, and preferred examples of the substituent include those represented by the formula (II)
The substituents on Q _y1 and R _{y1 to} R _{y6 in} Ia), (III-b) and (III-c) include those described above.

The polyalkylene oxide is preferably a salt composed of a combination of the above-mentioned organic and inorganic anions with an organic and inorganic cation. In this case, the mesogenic group for imparting liquid crystallinity is composed of an organic anion and an organic anion. It is contained in at least one of the organic cations.

As an electrolyte for a lithium ion battery or a lithium battery, A has an anion site and a mesogen group,
Preferably, the counter cation is a lithium ion.

For a solar cell using iodine ion as a carrier, it is preferable that A has a cation site and a mesogen group, and its counter anion is iodine ion.

The polyethylene oxide in the present invention is:
It is more preferable to include a structure represented by the formula (I) and a structure represented by the following formula (II). That is, if all side chains have a liquid crystalline portion, the material becomes hard (has low mobility), and the ionic conductivity is reduced. By using a copolymer with a monomer having no liquid crystalline side chain, flexibility can be imparted.

[0046]

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In the formula (II), R represents a hydrogen atom, a substituted or unsubstituted alkyl group (preferably having a number of carbon atoms (C
Number) is 1 to 24, and may be linear or branched, or may be cyclic, for example, methyl,
Ethyl, propyl, butyl, i-propyl, pentyl,
Hexyl, octyl, 2-ethylhexyl, t-octyl, decyl, dodecyl, tetradecyl, 2-hexyldecyl, octadecyl, cyclohexyl, cyclopentyl), or a substituted or unsubstituted aryl group (preferably having 6 to 24 carbon atoms such as phenyl, 4-methylphenyl, 3-cyanophenyl, 2-chlorophenyl, 2-naphthyl), and the substituents on the alkyl group or the aryl group include those represented by the formulas (III-a), (III-b) and (III-b). The substituents on Q _y1 and R _{y1 to} R _{y6 in} c) include those described above.

In the polyalkylene oxide of the present invention, the ratio of the alkylene oxide units represented by the formulas (I) and (II) is preferably from 1: 1 to 1:50, and preferably from 1: 3 to 1:50. 30 is more preferred.

[0049] The number average molecular weight of the polyalkylene oxide in the present invention is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint of ionic conductivity and mechanical strength of the electrolyte material, the number average molecular weight is not particularly limited. ~ 1,000,
000 is preferable, and 1,000 to 10,000 is more preferable.

Hereinafter, specific examples of the polyalkylene oxide containing the formulas (I) and (II) are shown, but the present invention is not limited thereto.

[0051]

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[0052]

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[0053]

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[0054]

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When the electrolyte composition of the present invention is used for the electrolyte of a photoelectrochemical cell, I ⁻ and I ₃ ⁻ are used as charge carriers.
It is preferable to use an electrolyte composition containing, and they can be added in the form of any salt. Preferred counter cations of the iodine salt are those of the above-mentioned formulas (III-a) and (III-
b) or (III-c).
I ₃ ^- salts, I ^- iodine (I ₂₎ was added in the presence salt, it is common to produce an electrolyte composition. At that time, the same amount of I ₃ ^{− as the} added I ₂ is generated.

The concentration of I ⁻ in the electrolyte composition of the present invention is 1
It is preferably from 0 to 90% by mass, more preferably from 30 to 70% by mass. In that case, all the remaining components are preferably compounds of the present invention.

[0057] I ₃ ^- is I ^- is preferably 0.1 to 50 mol% of, more preferably 0.1 to 20 mol%, more preferably from 0.5 to 10 mol% And most preferably 0.5 to 5 mol%.

The electrolyte composition of the present invention may further contain another molten salt, and preferably used molten salts are represented by the above formulas (III-a), (III-b) and (III-c). It is a combination of an organic cation and an optional anion, and the anion includes a halide ion (Cl ⁻ ,
Br ^{-, _{etc.), SCN -, BF 4 -}} , PF 6 -, ClO 4 -, (C
F ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , CH ₃ SO
_{^{3 -, CF 3 SO 3 -}} , CF 3 COO -, Ph 4 B -, (CF 3 S
O _{2) 3} C ^-, and the like as a preferable example, SCN ^-, C
More preferred are F ₃ SO ₃ ⁻ , CF ₃ COO ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ and BF ₄ ⁻ . Further, other iodine salts such as LiI, CF ₃ COOLi, CF ₃ COONa, Li
An alkali metal salt such as SCN and NaSCN can also be added. The addition amount of the alkali metal salt is 0.02 to 2
It is preferable that the amount is about mass%, more preferably 0.1 to 1 mass%.

The electrolyte composition of the present invention contains LiI, Na
Metal iodides such as I, KI, CsI and CaI ₂ , iodide salts of quaternary imidazolium compounds, iodide salts of tetraalkylammonium compounds, Br ₂ and LiBr, NaB
metal bromides such as r, KBr, CsBr, CaBr ₂ ,
Or Br ₂ and tetraalkyl ammonium bromide, bromine salts such as quaternary ammonium compounds pyridinium bromide, ferrocyanide - ferricyanide or ferrocene - metal complexes such as ferricinium ion, sodium polysulfide, alkylthiol - alkyl disulfide, etc. , A viologen dye, hydroquinone-quinone, and the like. When they are contained, the amount of these compounds used is preferably not more than 30% by mass of the entire electrolyte compound.

In the present invention, a solvent can be used together with the polyalkylene oxide, preferably up to the same mass as the compound.

The solvent used in the electrolyte composition of the present invention is
It is desirable that the compound be a compound having low viscosity to improve ionic mobility or high dielectric constant to improve the effective carrier concentration, thereby exhibiting excellent ionic conductivity. Examples of such a solvent include carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazolidinone, ether compounds such as dioxane and diethyl ether, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, and polyethylene. Chain ethers such as glycol dialkyl ether and polypropylene glycol dialkyl ether, alcohols such as methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether and polypropylene glycol monoalkyl ether, ethylene glycol, Propylene glycol, polyethylene glycol, polyp Polyhydric alcohols such as pyrene glycol and glycerin, nitrile compounds such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile and benzonitrile, esters such as carboxylic acid esters, phosphate esters and phosphonate esters, and dimethyl sulfo Non-proton polar substances such as oxide and sulfolane, water and the like can be used. Among them, ethylene carbonate, carbonate compounds such as propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazolidinone, acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, nitrile compounds such as benzonitrile, esters are particularly preferable. preferable. These may be used alone or in combination of two or more.

The boiling point of the solvent at normal pressure (1 atm) is preferably 200 ° C. or higher, more preferably 250 ° C. or higher, even more preferably 270 ° C. or higher, from the viewpoint of improving durability due to volatility.

Hereinafter, a photoelectrochemical cell in which the electrolyte composition of the present invention is preferably used will be described. The photoelectrochemical cell of the present invention is adapted to be used for a battery application in which the photoelectric conversion element works in an external circuit, and includes a photosensitive layer containing a semiconductor sensitive to radiation, a charge transfer layer, and a counter electrode. Have. This charge transfer layer contains the electrolyte composition of the present invention.

[Photoelectrochemical Cell] The photoelectrochemical cell of the present invention utilizing the electrolyte composition of the present invention will be described below. The photoelectrochemical cell of the present invention has a charge transfer layer containing the electrolyte composition, a photosensitive layer containing a semiconductor sensitized with a dye, and a counter electrode. It is designed to work with Since the charge transfer layer contains the electrolyte composition of the present invention, the photoelectrochemical cell of the present invention has excellent photoelectric conversion performance and exhibits excellent durability with little deterioration of battery performance over time.

[1] Photoelectric Conversion Element FIG. 1 shows an example of a photoelectric conversion element applicable to the present invention. The photoelectric conversion element 10 includes a conductive layer 12, an undercoat layer 14,
The photosensitive layer 16, the charge transfer layer 18, and the counter electrode conductive layer 20 are sequentially laminated. The photosensitive layer 16 includes the semiconductor layer 24 sensitized by the dye d and the charge transport material t. The semiconductor layer 24 is a porous layer made of semiconductor fine particles s, and voids are formed between the semiconductor fine particles s, and the charge transport material t has penetrated into the voids. The charge transport material t is composed of the same components as the material used for the charge transfer layer 18. Substrate 26 is located below conductive layer 12 and substrate 28 is located above counter electrode conductive layer 20.
Is arranged. The substrates 26 and 28 are for imparting strength to the photoelectric conversion element, and need not be provided. Also,
Boundary of each layer, for example, conductive layer 12 and photosensitive layer 16
At the boundary between the photosensitive layer 16 and the charge transfer layer 18, the boundary between the charge transfer layer 18 and the counter electrode conductive layer 20, and the like, the components of each layer may be mutually diffused and mixed. Light may be incident on the photoelectric conversion element 10 from one or both sides, and the conductive layer 12 on the light incident side and the substrate 26 and / or
Alternatively, the counter electrode conductive layer 20 and the substrate 28 can be made of a material having light transmittance.

Next, the operation of the photoelectric conversion element 10 will be described. The case where the semiconductor fine particles s are n-type will be described. When light enters the photoelectric conversion element 10, the incident light reaches the photosensitive layer 16 and is absorbed by the dye d and the like.
An excited state dye d is generated. The excited dye d, etc.,
Pass high-energy electrons to the conduction band of the semiconductor particles s,
The substance itself becomes an oxidant. The electrons transferred to the conduction band reach the conductive layer 12 by the network of the semiconductor fine particles s.
Therefore, the conductive layer 12 has a negative potential with respect to the counter electrode conductive layer 20. In a mode in which the photoelectric conversion element 10 is used for a photovoltaic cell, when this photovoltaic cell is connected to an external circuit, the electrons in the conductive layer 12 reach the counter electrode conductive layer 20 while working in the external circuit. When the charge transporting material is an electrolyte, the electrons reduce the electrolyte component (for example, I ⁻ ), and the generated reductant (for example, I ₃ ⁻ ) reduces the oxidized form of the dye d to return to the original state. By continuously irradiating light, a series of reactions occurs continuously, and electricity can be extracted.

Hereinafter, materials usable for each layer of the photoelectric conversion element and a method for forming the same will be described. In the following, when the term “conductive support” is used, only the conductive layer 12 is used.
In addition, the term “counter electrode” includes both the counter electrode conductive layer 20 alone and the one formed from the counter electrode conductive layer 20 and the optionally provided substrate 28.

(A) Conductive Support The conductive support comprises (1) a single layer of a conductive layer or (2) two layers of a conductive layer and a substrate. In the case of (1), a material that maintains sufficient strength and sealing properties is used as the conductive layer, and includes, for example, a metal material (platinum, gold, silver, copper, zinc, titanium, aluminum, or the like) Alloy) can be used. In the case of (2), a substrate having a conductive layer containing a conductive agent on the photosensitive layer side can be used. Preferred conductive agents include metals (for example, platinum, gold, silver, copper, zinc, titanium, aluminum, indium and the like or alloys containing them), carbon, and conductive metal oxides (indium-tin composite oxide, tin oxide). And the like doped with fluorine or antimony). The thickness of the conductive layer is 0.02-
About 10 μm is preferable.

The lower the surface resistance of the conductive support, the better. The preferred range of the surface resistance is 50 Ω / □ or less, more preferably 20 Ω / □ or less.

When light is irradiated from the conductive support side, the conductive support is preferably substantially transparent.
Substantially transparent means that it is in the visible to near infrared region (400 to
(1,200 nm) in part or all of the light.
It means 0% or more, preferably 50% or more, and more preferably 80% or more. In particular, it is preferable that the transmittance in a wavelength region where the photosensitive layer has sensitivity is high.

The transparent conductive support is preferably formed by forming a transparent conductive layer made of a conductive metal oxide on the surface of a transparent substrate such as glass or plastic by coating or vapor deposition. Preferred as the transparent conductive layer is tin dioxide or indium-tin oxide (ITO) doped with fluorine or antimony. As the transparent substrate, a glass substrate such as soda glass which is advantageous in terms of cost and strength and alkali-free glass which is not affected by alkali elution, and a transparent polymer film can be used. As materials for the transparent polymer film, triacetyl cellulose (TAC), polyethylene terephthalate (PE)
T), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), polyester sulfone (PES), polyimide (P
I), polyetherimide (PEI), cyclic polyolefin, brominated phenoxy and the like. In order to secure sufficient transparency, the amount of the conductive metal oxide applied is 0.01 to 100 g per 1 m ² of a glass or plastic support.
It is preferred that

It is preferable to use a metal lead for the purpose of lowering the resistance of the transparent conductive support. The material of the metal lead is
Metals such as platinum, gold, nickel, titanium, aluminum, copper and silver are preferred. It is preferable that the metal lead is provided on a transparent substrate by vapor deposition, sputtering, or the like, and a transparent conductive layer made of conductive tin oxide or an ITO film is provided thereon. The decrease in the amount of incident light due to the installation of metal leads is preferably 10
%, More preferably 1 to 5%.

(B) Photosensitive Layer The photosensitive layer has a function of absorbing light to perform charge separation and generate electrons and holes. The photosensitive layer includes a dye-sensitized semiconductor. In a dye-sensitized semiconductor, light absorption and thereby generation of electrons and holes mainly occur in the dye, and the semiconductor plays a role of receiving and transmitting the electrons (or holes). The semiconductor used in the present invention is preferably an n-type semiconductor which gives an anode current by conducting electrons as carriers under photoexcitation.

(1) Semiconductors Semiconductors include simple semiconductors such as silicon and germanium, III-V compound semiconductors, metal chalcogenides (eg, oxides, sulfides, selenides, and composites thereof), or Compounds having a perovskite structure (for example, strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate, etc.) can be used.

Preferred metal chalcogenides include titanium, tin, zinc, iron, tungsten, zirconium,
Hafnium, strontium, indium, cerium,
Examples include oxides of yttrium, lanthanum, vanadium, niobium, or tantalum, sulfides of cadmium, zinc, lead, silver, antimony or bismuth, selenides of cadmium or lead, and tellurides of cadmium. Other compound semiconductors include phosphides such as zinc, gallium, indium, and cadmium, selenides of gallium-arsenic or copper-indium, and sulfides of copper-indium. Further, M _x O _y S _z or M ¹ _x M ² _y O _z (M, M ¹ and M ² are metal elements, O is an oxygen atom, and x, y and z are combinations whose valence is neutral. Can be also preferably used.

Preferred examples of the semiconductor used in the present invention include Si, TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , Zn
O, Nb ₂ O ₅ , CdS, ZnS, PbS, Bi ₂ S ₃ , C
dSe, CdTe, SrTiO ₃ , GaP, InP, G
aAs, CuInS ₂ , CuInSe ₂ , and more preferably TiO ₂ , ZnO, SnO ₂ , Fe ₂ O ₃ , W
O ₃ , Nb ₂ O ₅ , CdS, PbS, CdSe, SrTi
O ₃ , InP, GaAs, CuInS ₂ and CuInS
a e _2, particularly preferably TiO ₂ and Nb ₂ O _5, and most preferably TiO _2. TiO ₂ is preferably TiO ₂ containing anatase 70%, especially TiO ₂ of preferably 100% anatase.
In addition, in order to increase the electronic conductivity in these semiconductors,
Doping with a metal is also effective. The metal to be doped is preferably a divalent or trivalent metal. In order to prevent a reverse current from flowing from the semiconductor to the charge transfer layer, 1
Doping with a valent metal is also effective.

The semiconductor used in the present invention may be a single crystal or polycrystal. However, from the viewpoints of production cost, securing of raw materials, energy payback time, etc., polycrystal is preferable, and a porous film composed of semiconductor fine particles is particularly preferable. In addition, a part of the amorphous portion may be included.

The particle size of the semiconductor fine particles is generally on the order of nm to μm, but the average particle size of the primary particles obtained from the diameter when the projected area is converted into a circle is preferably from 5 to 200 nm, and from 8 to 200 nm. 100 nm is more preferred. The average particle size of the semiconductor fine particles (secondary particles) in the dispersion is 0.0
1-30 micrometers is preferable. Two or more types of fine particles having different particle size distributions may be mixed. In this case, the average size of the small particles is preferably 25 nm or less, more preferably 10 nm or less. In order to scatter the incident light and improve the light capture rate, the particle diameter is large, for example, 100 n.
It is also preferable to mix semiconductor particles of m or more and about 300 nm.

A mixture of two or more different types of semiconductor fine particles may be used. When two or more types of semiconductor fine particles are used in combination, one type is preferably TiO ₂ , ZnO, Nb ₂ O ₅ or SrTiO ₃ . Another type is preferably SnO ₂ , Fe ₂ O ₃ or WO ₃ . A more preferred combination is ZnO
And SnO ₂ , ZnO and WO ₃ or ZnO, SnO ₂ and WO ₃
And the like. When two or more kinds of semiconductor fine particles are used as a mixture, the respective particle diameters may be different. In particular, a combination in which the semiconductor fine particles mentioned in the first type have a large particle diameter and the semiconductor fine particles mentioned in the second and subsequent types are small is preferable. Preferably, particles having a large particle size are 100 nm or more, and particles having a small particle size are 15 nm.
The following combinations are available.

As a method for producing semiconductor fine particles, there is described a method of Sol-Gel Method by Agio Shofusha (1998)
), A sol-gel method described in "Sol-gel method for thin film coating" (1995) of the Technical Information Association, etc.
Tadao Sugimoto, "Synthesis of Monodispersed Particles by New Synthesis Method Gel-Sol Method and Size Morphology Control", Materia, Vol.
No., pp. 1012 to 1018 (1996). Further, a method of producing an oxide by hydrolyzing a chloride in an oxyhydrogen salt at a high temperature developed by Degussa is also preferable.

When the semiconductor fine particles are titanium oxide, any of the above-mentioned sol-gel method, gel-sol method, and high-temperature hydrolysis method in chloride oxyhydrogen salt are preferred. Applied Technology "Gihodo Publishing (1997
) Can also be used.
Further, as a sol-gel method, Barbe et al., Journal of American Ceramic Society, No. 8
Volume 0, Issue 12, 3157-3171 (1997)
And the chemistry of Burnside et al.
Of Materials, Vol. 10, No. 9, 2419-2
The method described on page 425 is also preferred.

(2) Semiconductor Particle Layer The semiconductor is used, for example, in the form of a semiconductor particle layer formed on the conductive support. In order to coat the semiconductor fine particles on the conductive support, in addition to the method of applying a dispersion or colloid solution of the semiconductor fine particles on the conductive support, the above-mentioned sol-gel method or the like can also be used. In consideration of mass production of photoelectric conversion elements, physical properties of semiconductor fine particle liquid, flexibility of a conductive support, and the like, a wet film forming method is relatively advantageous. Typical examples of the wet film forming method include a coating method, a printing method, an electrolytic deposition method, and an electrodeposition method. In addition, a method of oxidizing a metal, a method of depositing a metal solution in a liquid phase by ligand exchange (LPD method), a method of vapor deposition by sputtering or the like, a CVD method, or a metal that thermally decomposes on a heated substrate An SPD method in which a metal oxide is formed by spraying an oxide precursor can also be used.

As a method for preparing a dispersion of semiconductor fine particles, in addition to the above-described sol-gel method, a method of grinding in a mortar, a method of dispersing while pulverizing using a mill, or a method of preparing a solvent when synthesizing a semiconductor. A method of precipitating fine particles in the solution and using it as it is, may be mentioned.

Examples of the dispersion medium include water and various organic solvents (eg, methanol, ethanol, isopropyl alcohol, citronellol, terpineol, dichloromethane, acetone, acetonitrile, ethyl acetate, etc.). During dispersion, if necessary, for example, polyethylene glycol, hydroxyethyl cellulose, polymers such as carboxymethyl cellulose, surfactant, acid,
Alternatively, a chelating agent or the like may be used as a dispersion aid. By changing the molecular weight of polyethylene glycol, it is possible to adjust the viscosity of the dispersion, to form a semiconductor layer that is difficult to peel off, and to control the porosity of the semiconductor layer. Therefore, it is preferable to add polyethylene glycol.

The application method includes a roller method and a dipping method as an application system, an air knife method and a blade method as a metering system.
8-4589, U.S. Pat. Nos. 2,681,294, 2,761,419, and 276.
For example, a slide hopper method, an extrusion method, a curtain method, and the like described in US Pat. As a general-purpose machine, a spin method or a spray method is also preferable. As the wet printing method, intaglio printing, rubber printing, screen printing, and the like are preferable, including three major printing methods of letterpress, offset and gravure. From these, a preferable film forming method is selected according to the liquid viscosity and the wet thickness.

The layer of semiconductor fine particles is not limited to a single layer, but a multi-layer coating of a dispersion of semiconductor fine particles having different particle diameters, or a coating layer containing semiconductor fine particles of different types (or different binders and additives) may be formed in multiple layers. It can also be applied. Multilayer coating is effective even when the film thickness is insufficient by one coating.

In general, as the thickness of the semiconductor fine particle layer (same as the thickness of the photosensitive layer) becomes larger, the amount of dye carried per unit projected area increases, so that the light capture rate increases, but the diffusion distance of generated electrons increases. Therefore, the loss due to charge recombination also increases. Therefore, the preferable thickness of the semiconductor fine particle layer is 0.1 to 100 μm. When used in a photovoltaic cell, the thickness of the semiconductor fine particle layer is preferably 1 to 30 μm, and 2 to 25 μm.
μm is more preferred. The coating amount of the semiconductor fine particles per 1 m ² of the support is preferably 0.5 to 100 g,
~ 50 g is more preferred.

After applying the semiconductor fine particles on the conductive support, the semiconductor fine particles are brought into electronic contact with each other,
Heat treatment is preferably performed to improve the strength of the coating film and the adhesion to the support. A preferable heating temperature range is 40 ° C. or more and 700 ° C. or less, more preferably 1 ° C.
It is not less than 00 ° C and not more than 600 ° C. The heating time is about 10 minutes to 10 hours. When a support having a low melting point or softening point such as a polymer film is used, high-temperature treatment is not preferable because it causes deterioration of the support. From the viewpoint of cost, the temperature is preferably as low as possible (for example, 50 to 350 ° C.). The temperature can be lowered by heat treatment in the presence of small semiconductor particles of 5 nm or less, mineral acid, or a metal oxide precursor. Irradiation with ultraviolet rays, infrared rays, microwaves, or the like, application of an electric field, or ultrasonic waves Can also be performed. At the same time, for the purpose of removing unnecessary organic substances and the like, it is preferable to use a combination of heating, decompression, oxygen plasma treatment, pure water cleaning, solvent cleaning, gas cleaning and the like in addition to the above irradiation and application, as appropriate.

After the heat treatment, for example, chemical plating using an aqueous solution of titanium tetrachloride may be performed to increase the surface area of the semiconductor fine particles, increase the purity in the vicinity of the semiconductor fine particles, and increase the efficiency of electron injection from the dye into the semiconductor fine particles. Electrochemical plating using an aqueous solution of titanium trichloride may be performed. In order to prevent a reverse current from flowing from the semiconductor fine particles to the charge transfer layer, it is also effective to adsorb an organic substance having low electron conductivity other than the dye on the particle surface. As the organic substance to be adsorbed, a substance having a hydrophobic group is preferable.

It is preferable that the semiconductor fine particle layer has a large surface area so that many dyes can be adsorbed. The surface area in a state where the layer of the semiconductor fine particles is applied on the support is preferably 10 times or more, more preferably 100 times or more with respect to the projected area. The upper limit is not particularly limited, but is usually about 1000 times.

(3) Dye The sensitizing dye used in the photosensitive layer may be any compound that can absorb semiconductors in the visible or near-infrared region and can sensitize a semiconductor. Examples thereof include organometallic complex dyes and methine dyes. , Porphyrin dyes and phthalocyanine dyes are preferred. Also,
Two or more types of dyes can be used in combination or mixed in order to widen the wavelength range of photoelectric conversion as much as possible and increase the conversion efficiency. In this case, the pigments to be used or mixed and the ratio thereof can be selected so as to match the wavelength range and the intensity distribution of the target light source.

[0092] Such a dye can be used as a suitable interlocking group having an adsorption ability to the surface of the semiconductor fine particles.
p) is preferred. Preferred linking groups, COOH groups, OH groups, SO ₃ H group, -P (O) (O
Examples include acidic groups such as H) ₂ group and —OP (O) (OH) ₂ group, or chelating groups having π conductivity such as oxime, dioxime, hydroxyquinoline, salicylate or α-keto enolate. Above all, CO
OH group, -P (O) (OH) ₂ group and -OP (O)
(OH) ₂ groups are particularly preferred. These groups may form a salt with an alkali metal or the like, or may form an intramolecular salt. In the case of a polymethine dye, when the methine chain contains an acidic group such as a case where a squarylium ring or a croconium ring is formed, the methine chain may have this portion as a bonding group.

Hereinafter, preferred sensitizing dyes for use in the photosensitive layer will be specifically described. (A) Organic metal complex dye When the dye is a metal complex dye, a metal phthalocyanine dye, a metal porphyrin dye, and a ruthenium complex dye are preferable, and a ruthenium complex dye is particularly preferable. Ruthenium complex dyes include, for example, US Pat. No. 4,927,721.
Nos. 4,684,537, 5,084,365, and 53
No. 50644, No. 5463057, No. 5525440
And Japanese Patent Application Laid-Open No. 7-249790, Japanese Patent Application Laid-Open No. 10-504512, and World Patent 98/50393.
And complex dyes described in JP-A-2000-26487.

When the dye is a ruthenium complex dye, a ruthenium complex dye represented by the following formula (V) is preferable. General formula (V) (A ¹ ) _t Ru (Ba) _u (Bb) _v (Bc) _{w In the} general formula (V), A ¹ represents a mono- or bidentate ligand. . A ¹ is Cl, SCN, H ₂ O, Br, I, CN, NC
It is preferably a ligand selected from the group consisting of O, SeCN, α-diketones, oxalic acid and derivatives of dithiocarbamic acid. when t is 2 or more, 2 or more of A ¹ may be the same or different. In the general formula (V), B-
a, Bb and Bc are each independently the following formula (B-
1) represents a ligand represented by any of (B-10). t represents an integer of any of 0 to 3, and u, v and w
Represents 0 or 1, respectively, and is appropriately combined depending on the kind of ligand so that the ruthenium complex represented by the general formula (V) becomes a six-coordinate complex.

[0095]

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In the above formulas (B-1) to (B-10), R ^a
Represents a hydrogen atom or a substituent; examples of the substituent include a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 12 carbon atoms, Examples thereof include a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, an acidic group (these acidic groups may form a salt) or a chelating group. The alkyl part of the alkyl group and the aralkyl group may be linear or branched. The aryl part of the aryl group and the aralkyl group may be monocyclic or polycyclic (condensed ring, ring assembly). In the general formula (V), Ba, Bb and Bc may be the same or different.

Preferred specific examples (exemplary compounds R-1 to R-17) of the organometallic complex dyes are shown below, but the dyes used in the present invention are not limited to the following specific examples.

[0098]

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[0099]

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(B) Methine Dye Preferred methine dyes used in the present invention are polymethine dyes such as cyanine dyes, merocyanine dyes, and squarylium dyes. Examples of the polymethine dye preferably used in the present invention include, for example, JP-A-11-35836.
JP-A-11-67285, JP-A-11-8691
6, JP-A-11-97725, JP-A-11-158
395, JP-A-11-163378, JP-A-11-163
214730, JP-A-11-214731, JP-A-11-238905, JP-A-2000-26487,
European Patent Nos. 892411, 911841 and 99
The dyes described in each of the specifications of No. 1092 can be used. Specific examples of preferred methine dyes are shown below.

[0101]

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[0102]

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(4) Adsorption of Dye on Semiconductor Fine Particles The dye is adsorbed on the semiconductor fine particles by dipping a conductive support having a well-dried semiconductor fine particle layer in a dye solution or by dissolving the dye solution in a semiconductor solution. A method of applying to the fine particle layer can be used. In the former case, a dipping method, a dipping method, a roller method, an air knife method, or the like can be used. In the case of the immersion method, the dye may be adsorbed at room temperature or may be heated and refluxed as described in JP-A-7-249790. Examples of the latter coating method include a wire bar method, a slide hopper method, an extrusion method, a curtain method, a spin method, and a spray method. Preferred solvents for dissolving the dye include, for example, alcohols (methanol, ethanol, t-butanol, benzyl alcohol, etc.), nitriles (acetonitrile, propionitrile, 3-methoxypropionitrile, etc.),
Nitromethane, halogenated hydrocarbons (dichloromethane,
Dichloroethane, chloroform, chlorobenzene, etc.),
Ethers (eg, diethyl ether, tetrahydrofuran), dimethyl sulfoxide, amides (eg, N, N-dimethylformamide, N, N-dimethylacetamide),
N-methylpyrrolidone, 1,3-dimethylimidazolidinone, 3-methyloxazolidinone, esters (ethyl acetate, butyl acetate, etc.), carbonates (diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), ketones (acetone, 2-butanone, cyclohexanone, etc.), hydrocarbons (hexane, petroleum ether, benzene, toluene, etc.)
And a mixed solvent thereof.

The total amount of the dye adsorbed is 0.01 to 100 mmol per unit surface area (1 m ² ) of the porous semiconductor electrode substrate.
l is preferred. The amount of the dye adsorbed on the semiconductor fine particles is preferably in the range of 0.01 to 1 mmol per 1 g of the semiconductor fine particles. By setting the dye adsorption amount in the above range, a sufficient sensitizing effect in the semiconductor can be obtained. On the other hand, if the amount of the dye is too small, the sensitizing effect becomes insufficient, and if the amount of the dye is too large, the dye not adhering to the semiconductor floats and causes a reduction in the sensitizing effect. In order to increase the amount of the dye adsorbed, it is preferable to perform a heat treatment before the adsorption. After the heat treatment, in order to prevent water from adsorbing on the surface of the semiconductor fine particles, it is preferable to quickly perform the dye adsorption operation at a temperature of the semiconductor electrode substrate of 60 to 150 ° C. without returning to normal temperature. For the purpose of reducing the interaction such as aggregation between the dyes, a colorless compound may be added to the dyes and co-adsorbed to the semiconductor fine particles. Compounds effective for this purpose are compounds having surface active properties and structures, and include, for example, steroid compounds having a carboxyl group (for example, chenodeoxycholic acid) and sulfonates such as those described below.

[0105]

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The unadsorbed dye is preferably removed by washing immediately after the adsorption. It is preferable to perform washing with a polar solvent such as acetonitrile and an organic solvent such as an alcohol solvent using a wet washing tank. After the dye is adsorbed, the surface of the semiconductor fine particles may be treated with an amine or a quaternary salt. Preferred amines include pyridine, 4-t-
Butyl pyridine and polyvinyl pyridine and the like,
Preferred quaternary salts include tetrabutylammonium iodide and tetrahexylammonium iodide. When these are liquids, they may be used as they are, or may be used after being dissolved in an organic solvent.

(C) Charge Transfer Layer The charge transfer layer is a layer containing a charge transporting material having a function of replenishing an oxidized dye with electrons. Examples of typical charge transporting materials that can be used for the charge transfer layer include (i) a solution in which redox pair ions are dissolved (electrolyte solution), and a redox pair solution as a polymer matrix. And a so-called gel electrolyte impregnated in the gel, a molten salt electrolyte containing a redox counter ion, and a solid electrolyte. In addition to charge transport materials involving ions, (ii) charge transport materials involving carrier transport in solids include electron transport materials and holes.
Transport materials can also be used. In the present invention, the electrolyte composition of the present invention is used for the charge transfer layer, but other charge transport materials described above may be used in combination.

(1) Formation of Charge Transfer Layer There are two methods for forming the charge transfer layer. One is a method in which a counter electrode is first stuck on the photosensitive layer, and a liquid charge transfer layer is sandwiched in the gap. The other is a method in which a charge transfer layer is provided directly on the photosensitive layer, and a counter electrode is subsequently provided.

In the former case, as a method of sandwiching the charge transfer layer, a normal pressure process utilizing a capillary phenomenon due to immersion or the like,
Alternatively, a vacuum process in which the gas phase in the gap is replaced with a liquid phase at a pressure lower than normal pressure can be used.

In the latter case, the wet type charge transfer layer is provided with a counter electrode in an undried state to take measures to prevent liquid leakage at the edge portion. In the case of a gel electrolyte, there is a method of applying the composition in a wet manner and solidifying it by a method such as polymerization. In this case, a counter electrode can be provided after drying and fixing. As a method for applying a wet organic hole transport material or a gel electrolyte in addition to the electrolytic solution, a method similar to the method for applying the semiconductor fine particle layer or the dye described above can be used.

(D) Counter electrode Like the above-mentioned conductive support, the counter electrode may have a single-layer structure of a counter electrode conductive layer made of a conductive material, or may be composed of a counter electrode conductive layer and a support substrate. Examples of the conductive material used for the counter electrode conductive layer include metal (for example, platinum, gold, silver, copper, aluminum, magnesium, indium, and the like), carbon, and conductive metal oxide (indium-tin composite oxide, fluorine-doped tin oxide, and the like). ). Among them, platinum,
Gold, silver, copper, aluminum, and magnesium can be preferably used as the counter electrode conductive layer. An example of a preferable support substrate for the counter electrode is glass or plastic, to which the above-described conductive agent is applied or vapor-deposited. The thickness of the counter electrode conductive layer is not particularly limited, but is preferably 3 nm to 10 μm. The lower the surface resistance of the counter electrode conductive layer, the better. The preferable range of the surface resistance is 50Ω / □ or less, and more preferably 20Ω / □ or less.

Since light may be irradiated from one or both of the conductive support and the counter electrode, at least one of the conductive support and the counter electrode must be substantially transparent in order for the light to reach the photosensitive layer. I just need. From the viewpoint of improving the power generation efficiency, it is preferable that the conductive support is made transparent and light is incident from the conductive support side. In this case, the counter electrode preferably has a property of reflecting light. As such a counter electrode, glass or plastic on which a metal or a conductive oxide is deposited, or a metal thin film can be used.

As the counter electrode, a conductive material may be applied directly on the charge transfer layer, plated or vapor-deposited (PVD, CVD), or may be attached to the counter electrode conductive layer side of the substrate having the counter electrode conductive layer.
Further, similarly to the case of the conductive support, it is preferable to use a metal lead for the purpose of reducing the resistance of the counter electrode, particularly when the counter electrode is transparent. In addition, the preferable material and the installation method of the metal lead, the decrease in the amount of incident light due to the installation of the metal lead, etc.
This is the same as the case of the conductive support.

(E) Other layers In order to prevent a short circuit between the counter electrode and the conductive support, a dense semiconductor thin film layer is previously coated between the conductive support and the photosensitive layer as an undercoat layer. It is particularly effective when an electron transporting material or a hole transporting material is used for the charge transfer layer. Preferred as the undercoat layer are TiO ₂ , SnO ₂ ,
Fe ₂ O ₃ , WO ₃ , ZnO and Nb ₂ O ₅ , more preferably TiO ₂ . The undercoat layer is, for example, Electroch
In addition to the spray pyrolysis method described in Im. Acta 40, 643-652 (1995), it can be applied by a sputtering method or the like. The preferred thickness of the undercoat layer is 5 to 1000 nm, more preferably 10 to 500 nm.

A functional layer such as a protective layer or an antireflection layer may be provided on the outer surface of one or both of the conductive support serving as an electrode and the counter electrode, between the conductive layer and the substrate, or between the substrates. Good. For forming these functional layers, a coating method, a vapor deposition method, a sticking method, or the like can be used depending on the material.

In the photoelectrochemical cell of the present invention, it is preferable to seal the side surfaces with a polymer, an adhesive or the like in order to prevent the above-mentioned components from deteriorating and the contents from volatilizing.

The photoelectrochemical cell of the present invention has basically the same configuration as that of the photoelectric conversion element. The photoelectric conversion element is connected to an external circuit via a lead wire or the like so that work is performed in the external circuit. It is what was constituted. As the external circuit itself connected to the conductive support and the counter electrode via a lead wire or the like, a known circuit can be used. Further, the photoelectrochemical cell of the present invention can have a module structure basically similar to a conventional solar cell module. The solar cell module generally has a structure in which cells are formed on a support substrate such as a metal and a ceramic, and the cells are covered with a filling resin or a protective glass to take in light from the opposite side of the support substrate. Alternatively, it is also possible to adopt a structure in which a transparent material such as tempered glass is used for the support substrate, a cell is formed thereon, and light is taken in from the transparent support substrate side. Specifically, a superstrate type, a substrate type, a module structure called a potting type, a substrate-integrated module structure used in an amorphous silicon solar cell, and the like are known, and the photoelectrochemical cell of the present invention is also used and used. These module structures can be appropriately selected depending on the place and environment. Specifically, JP-A-2000-268
It is preferable to apply the structure and mode described in JP-A-892.

[Non-Aqueous Secondary Battery] The non-aqueous secondary battery of the present invention utilizing the electrolyte composition of the present invention will be described below. The non-aqueous secondary battery of the present invention is characterized by containing the electrolyte composition of the present invention. Since the non-aqueous secondary battery of the present invention contains the electrolyte composition of the present invention, it exhibits excellent cyclability without greatly reducing the capacity.

When the electrolyte composition of the present invention is used in a non-aqueous secondary battery, the positive electrode active material may be a transition metal oxide capable of reversibly inserting and releasing lithium ions, but a lithium-containing transition metal oxide is particularly preferable. . Preferred lithium-containing transition metal oxide positive electrode active materials used in the present invention include lithium-containing Ti, V, Cr, Mn, Fe, Co,
An oxide containing Ni, Cu, Mo, and W may be used. Alkali metals other than lithium (first (IA) of the periodic table)
Group II, Group IIA) elements, and / or Al, Ga,
In, Ge, Sn, Pb, Sb, Bi, Si, P, B, etc. may be mixed. The mixing amount is 0 to 3 with respect to the transition metal.
0 mol% is preferred.

More preferred lithium-containing transition metal oxide positive electrode active materials used in the present invention include lithium compounds / transition metal compounds (where transition metals are Ti, V,
It is preferable to mix and synthesize such that the total molar ratio of Cr, Mn, Fe, Co, Ni, Mo, and W) is 0.3 to 2.2.

Particularly preferred lithium-containing transition metal oxide cathode active materials used in the present invention include lithium compounds / transition metal compounds (where transition metals are V, Cr,
At least one selected from Mn, Fe, Co, Ni)
It is preferable to mix and synthesize so that the total molar ratio of the above is 0.3 to 2.2.

Particularly preferred lithium-containing transition metal oxide cathode active material used in the present invention is Li _g M ³ O ₂ (M ³ is at least one selected from Co, Ni, Fe and Mn, g =
Material containing 0 to 1.2), or ^{_{Li h M 4 2 O 4 (}} M 4 is M
n, h = 0 to 2) and having a spinel structure, wherein M ³ and M ⁴ are Al, G
a, In, Ge, Sn, Pb, Sb, Bi, Si, P or B may be mixed. The mixing amount is preferably 0 to 30 mol% based on the transition metal.

As the most preferred lithium-containing transition metal oxide positive electrode active material used in the present invention, Li _g Co
O ₂ , Li _g NiO ₂ , Li _g MnO ₂ , Li _g Co _j Ni
_(1-j) O ₂ , Li _h Mn ₂ O ₄ (where g = 0.2-1.
2, j = 0.1 to 0.9, h = 0 to 2).
Here, the above-mentioned g value is a value before the start of charging and discharging, and increases or decreases due to charging and discharging.

The positive electrode active material can be synthesized by a known method such as a method of mixing and firing a lithium compound and a transition metal compound, and a solution reaction, but the firing method is particularly preferable.

The average particle size of the positive electrode active material used in the present invention is not particularly limited, but is preferably 0.1 to 50 μm. The specific surface area is not particularly limited, but is preferably 0.01 to 50 m ² / g by the BET method. In addition, the positive electrode active material 5
The pH of the supernatant when g is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

To obtain a predetermined particle size, a well-known pulverizer or classifier can be used. For example, a mortar, a ball mill, a vibrating ball mill, a vibrating mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. The positive electrode active material obtained by firing may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

One of the negative electrode active materials used in the present invention is:
It is a carbonaceous material that can store and release lithium. The carbonaceous material is a material substantially composed of carbon. For example,
Examples of the carbonaceous material include artificial graphite such as petroleum pitch, natural graphite, vapor-grown graphite, and various synthetic resins such as PAN-based resin and furfuryl alcohol resin. Further, PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA
Various types of carbon fibers such as base carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers, mesophase microspheres, graphite whiskers, and flat graphite can also be mentioned. These carbonaceous materials can be classified into non-graphitizable carbon materials and graphite-based carbon materials according to the degree of graphitization. Further, the carbonaceous material preferably has a plane spacing, a density, and a crystallite size described in JP-A-62-22066, JP-A-2-6856, and JP-A-3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, or the like is used. Can also.

Other examples of the negative electrode active material that can be used in the present invention include oxides and / or chalcogenides. Particularly, an amorphous oxide and / or a chalcogenide are preferable. The term “amorphous” as used herein refers to a substance having a broad scattering band having an apex in a range of 20 ° to 40 ° in 2θ value by an X-ray diffraction method using CuKα ray. May have. Preferably 40 ° or more in 2θ value 7
The strongest intensity of the crystalline diffraction lines observed at 0 ° or less is 100 times or less the intensity of the diffraction line at the apex of the broad scattering band seen at 20 ° or more and 40 ° or less in 2θ value, more preferably It is 5 times or less, and particularly preferably does not have a crystalline diffraction line.

In the present invention, an amorphous oxide of a metalloid element and / or a chalcogenide are particularly preferable, and an element belonging to Group 13 (IIIB) to Group 15 (VB), Al, G
An oxide or chalcogenide consisting of a, Si, Sn, Ge, Pb, Sb, Bi alone or a combination of two or more thereof is selected.

For example, Ga_TwoO_Three, SiO, GeO, Sn
O, SnO_Two, PbO, PbO_Two, Pb_TwoO_Three, Pb_TwoO_Four,
Pb_ThreeO_Four, Sb_TwoO_Three, Sb_TwoO_Four, Sb_TwoO_Five, Bi_TwoO_Three,
Bi _TwoO_Four, SnSiO_Three, GeS, SnS, SnS_Two, P
bS, PbS_Two, Sb_TwoS_Three, Sb_TwoS_Five, SnSiS_ThreeSuch
Is preferred. These are complex acids with lithium oxide.
Compound, for example, Li_TwoSnO_TwoIt may be.

In the negative electrode material of the present invention, S
An amorphous oxide mainly composed of n, Si, and Ge is more preferable, and an amorphous oxide represented by the following general formula (VI) is particularly preferable. In the general formula _{^{(VI) SnM 1 d M 2}} e O f formula, M ¹ is, Al, B, represents at least one element selected from P and Ge, M ² is the Periodic Table 1 (I
A) represents at least one or more elements selected from Group A, Group 2 (IIA), Group 3 (IIIA) and halogen elements, d is a number from 0.2 to 2 and e is 0.0
0.2 <d + e <2, where f is a number from 1 to 1, and f represents a number from 1 to 6.

The amorphous oxide mainly composed of Sn includes:
For example, the following compounds may be mentioned, but the present invention is not limited thereto. C-1 SnSiO ₃ C-2 Sn _0.8 Al _0.2 B _0.3 P _0.2 Si _0.5 O _3.6 C-3 SnAl _0.4 B _0.5 Cs _0.1 P _0.5 O _3.65 C-4 SnAl _0.4 B _0.5 Mg _0.1 P _0.5 O _3.7 C-5 SnAl _0.4 B _0.4 Ba _0.08 P _0.4 O _3.28 C-6 SnAl _0.4 B _0.5 Ba _0.08 Mg _0.08 P _0.3 O _3.26 C-7 SnAl _0.1 B _0.2 Ca _0.1 P _0.1 Si _0.5 O _3.1 C-8 SnAl _0.2 B _0.4 Si _0.4 O _2.7 C-9 SnAl _0.2 B _0.1 Mg _0.1 P _0.1 Si _0.5 O _2.6 C-10 SnAl _0.3 B _0.4 P _0.2 Si _0.5 O _3.55 C-11 SnAl _0.3 B _0.4 P _0.5 Si _0.5 O _4.3 C-12 SnAl _0.1 B _0.1 P _0.3 Si _0.6 O _3.25 C-13 SnAl _0.1 B _0.1 Ba _0.2 P _0.1 Si _0.6 O _2.95 C-14 SnAl _0.1 B _0.1 Ca _0.2 P _0.1 Si _0.6 O _2.95 C-15 SnAl _0.4 B _0.2 Mg _0.1 Si _0.6 O _3.2 C-16 SnAl _0.1 B _0.3 P _0.1 Si _0.5 O _3.05 C-17 SnB _0.1 K _0.5 P _0.1 SiO _3.65 C-18 SnB _0.5 F _0.1 Mg _0.1 P _0.5 O _3.05 The amorphous oxide and / or chalcogenite in the present invention is calcined. Any of a method and a solution method can be adopted, but a firing method is more preferable. In the firing method, it is preferable that the oxides, chalcogenites or compounds of the corresponding elements are mixed well and then fired to obtain an amorphous oxide and / or chalcogenite. These can be produced by a known method.

The average particle size of the negative electrode material used in the present invention is preferably 0.1 to 60 μm. To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibration ball mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed if necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be performed both in a dry type and a wet type.

In the present invention, as the negative electrode material which can be used in combination with the amorphous oxide negative electrode material mainly composed of Sn, Si and Ge, a carbon material which can occlude and release lithium ions or lithium metal; , Lithium alloys, and metals that can be alloyed with lithium.

An aprotic organic solvent is added to the electrode mixture used in the present invention, in addition to a conductive agent, a binder and a filler.

The above-mentioned conductive agent may be used in a battery comprising:
Any material may be used as long as it does not cause a chemical change. Usually, natural graphite (scale graphite, flaky graphite, earthy graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber and metal powder (copper, nickel, aluminum, silver (JP-A-63-63)) 148554
), Or a conductive material such as a metal fiber or a polyphenylene derivative (Japanese Patent Application Laid-Open No. 59-20971) can be included alone or as a mixture thereof. A combination of graphite and acetylene black is particularly preferred. The addition amount is preferably 1 to 50% by mass, particularly 2 to 30% by mass.
Is preferred. For carbon and graphite, 2 to 15% by mass is particularly preferable.

In the present invention, a binder for holding the electrode mixture can be used. Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Preferred binders are starch, carboxymethylcellulose, cellulose, diacetylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium alginate,
Polyacrylic acid, sodium polyacrylate, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylonitrile,
Water-soluble polymers such as polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleic acid copolymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride- (Meth) acrylic acid esters such as tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, and 2-ethylhexyl acrylate (Meth) acrylic acid ester copolymer, (meth) acrylic acid ester-acrylonitrile copolymer, and poly (vinyl alcohol) containing vinyl ester such as vinyl acetate Nylester copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene, neoprene rubber, fluoro rubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, phenol resin, epoxy An emulsion (latex) such as a resin or a suspension may be used. Particularly preferred are polyacrylate latex, carboxymethyl cellulose, polytetrafluoroethylene, and polyvinylidene fluoride. These binders can be used alone or in combination. If the amount of the binder is small, the holding power and cohesive strength of the electrode mixture are weak. If it is too large, the electrode volume increases, and the capacity per unit volume or unit mass of the electrode decreases. For these reasons, the amount of binder added is 1
-30 mass% is preferable, and especially 2-10 mass% is preferable.

As the filler, any fibrous material that does not cause a chemical change in the constructed battery can be used. Usually, fibers such as olefin-based polymers such as polypropylene and polyethylene, glass, and carbon are used. The amount of the filler added is not particularly limited, but is preferably 0 to 30% by mass.

The electrolyte composition of the present invention can be used in combination with a separator to ensure safety. The separator used together to ensure safety is 80
It is necessary to have a function of closing the above gap at a temperature of not less than 0 ° C. to increase the resistance and interrupt the current, and it is preferable that the closing temperature is 90 ° C. or more and 180 ° C. or less.

The shape of the holes in the separator is usually circular or elliptical, the size is 0.05 to 30 μm,
0 μm is preferred. Further, as in the case of making by a stretching method or a phase separation method, the holes may be rod-shaped or amorphous. The ratio occupied by these gaps, that is, the porosity is 20 to 90%, preferably 35 to 80%.

These separators are made of polyethylene,
It may be a single material such as polypropylene or a composite material of two or more types. In particular, those obtained by laminating two or more kinds of microporous films having different pore diameters, porosity, and pore closing temperatures are particularly preferable.

As the current collector for the positive and negative electrodes, an electron conductor that does not cause a chemical change in the constructed battery is used. As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, titanium, and the like, those obtained by treating carbon, nickel, titanium, or silver on the surface of aluminum or stainless steel are preferable, and aluminum and aluminum are particularly preferable. Alloy. As the current collector of the negative electrode, copper, stainless steel, nickel, and titanium are preferable, and copper and a copper alloy are particularly preferable.

The shape of the current collector is usually a film sheet, but a net, a punched material, a lath, a porous material, a foam, a molded product of a fiber group and the like can also be used. . The thickness is not particularly limited, but is 1 to 500
μm. It is also desirable that the surface of the current collector be made uneven by surface treatment.

The shape of the battery can be applied to any of sheets, corners, cylinders and the like. The mixture of the positive electrode active material and the negative electrode material is applied (coated) on the current collector, dried and compressed,
Mainly used. As a coating method, for example, a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a curtain method, a gravure method,
Bar method, dip method and squeeze method can be mentioned. Among them, a blade method, a knife method and an extrusion method are preferred. The coating is preferably performed at a speed of 0.1 to 100 m / min. At this time, by selecting the above coating method in accordance with the solution physical properties and drying properties of the mixture, a good surface state of the coated layer can be obtained. The coating may be performed on one side at a time or on both sides simultaneously.

The coating may be continuous, intermittent, or striped. The thickness, length and width of the coating layer are determined by the shape and size of the battery, but the thickness of the coating layer on one side is
In a compressed state after drying, the thickness is preferably 1 to 2000 μm.

The method for drying and dehydrating the electrode sheet coating material is as follows.
Hot air, vacuum, infrared rays, far-infrared rays, electron beams and low-humidity air can be used alone or in combination. The drying temperature is preferably in the range of 80 to 350 ° C, particularly 100 to 350 ° C.
A range of 250 ° C. is preferred. The water content is 20
It is preferably at most 00 ppm, and more preferably at most 500 ppm for each of the positive electrode mixture, the negative electrode mixture and the electrolyte. As a method for pressing the sheet, a method generally used can be used, but a calendar press method is particularly preferable. The pressing pressure is not particularly limited, but is 0.2 to 3 t.
/ Cm ² is preferred. The press speed of the calender press method is preferably 0.1 to 50 m / min, and the press temperature is room temperature to
200 ° C. is preferred. The ratio of the negative electrode sheet width to the positive electrode sheet is preferably 0.9 to 1.1, and more preferably 0.95 to 1.0.
Is particularly preferred. The content ratio between the positive electrode active material and the negative electrode material is
It depends on the compound type and the mixture formulation.

After the positive and negative electrode sheets are overlapped with a separator interposed therebetween, they are processed into a sheet-like battery or folded and inserted into a rectangular can, and the can and the sheet are electrically connected. A prismatic battery is formed by injecting the electrolyte composition of the present invention and using a sealing plate. Also, after the positive and negative electrode sheets are overlapped and wound via a separator, inserted into a cylindrical can, and the can and sheet are electrically connected,
The electrolyte composition of the present invention is injected, and a cylinder battery is formed using a sealing plate. At this time, a safety valve can be used as a sealing plate. In addition to the safety valve, various conventionally known safety elements may be provided. For example, a fuse, a bimetal, a PTC element, or the like is used as the overcurrent prevention element.

In addition to the safety valve, as a countermeasure against an increase in the internal pressure of the battery can, a method of making a cut in the battery can, a method of cracking a gasket, a method of cracking a sealing plate, or a method of cutting from a lead plate can be used. Further, the charger may be provided with a protection circuit incorporating measures for overcharging or overdischarging, or may be connected independently.

As a measure against overcharging, a method of interrupting the current by increasing the internal pressure of the battery can be provided. At this time, a compound for increasing the internal pressure can be contained in the mixture or the electrolyte. Examples of compounds used to increase the internal pressure include Li ₂ CO ₃ , LiHCO ₃ , Na ₂ C
Examples thereof include carbonates such as O ₃ , NaHCO ₃ , CaCO ₃ , and MgCO ₃ .

For the can or the lead plate, a metal or an alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum or alloys thereof are used.

As the method for welding the cap, can, sheet and lead plate, known methods (for example, DC or AC electric welding, laser welding, ultrasonic welding) can be used. A conventionally known compound or mixture such as asphalt can be used as the sealing agent for closing.

The application of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when mounted on an electronic device, a notebook computer, a pen-input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone handset ,
Pager, handy terminal, mobile fax,
Portable copy, portable printer, headphone stereo,
Video movies, LCD TVs, handy cleaners,
Portable CD, mini disk, electric shaver, transceiver, electronic organizer, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, and the like. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game machines, road conditioners, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder fir machines, etc.). Furthermore, it can be used for various military purposes and space applications. Further, it can be combined with a solar cell.

[0153]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. (Example 1) Synthesis example of polyalkylene oxide Synthesis of Exemplified Compound P-1

[0154]

Embedded image

Synthesis of Intermediate M-1 58.1 g (439 mmol) of dimethyl malonate was dissolved in methanol, and 88 ml of a 28% solution of sodium methoxide in methanol was added.
After dropping 2 g (439 mmol) over 1 hour, 8
Refluxed for hours. The reaction mixture was poured into diluted hydrochloric acid, neutralized, and extracted with ethyl acetate. The extract was dried over magnesium sulfate, concentrated under reduced pressure, and the residue was distilled under reduced pressure to obtain 41 g of M-1.
(A fraction at 399 Pa (3 mmHg) / 82 ° C.).

Synthesis of Intermediate M-2 Lithium aluminum hydride (11 g, 289 mmol)
l) was dispersed in 150 ml of diethyl ether, and M-1 (41 g, 170
(mmol) in 50 ml of diethyl ether was added dropwise over 2 hours. After the dropwise addition, after refluxing for 3 hours,
The reaction mixture was slowly poured into dilute hydrochloric acid / ice and extracted after acidifying the solution. After the extract was dried over magnesium sulfate, the solvent was distilled off under reduced pressure to obtain 31 g of an oily product as a crude product. The crude product was purified by silica gel column chromatography,
M-2, 14 g, was obtained as a colorless oil.

Synthesis of Intermediate M-4 M-2 (13.85 g, 64 mmol) obtained above and M
-3 (6.86 g, 64 mmol) in 50 ml of toluene
And 12 g of paratoluenesulfonic acid was added, and the mixture was heated under reflux for 5 hours while distilling off water. The reaction mixture was poured into 100 ml of water to which 10 g of potassium carbonate had been added, and extracted with ethyl acetate. After the extract was dried, the solvent was distilled off under reduced pressure.
The residue was recrystallized from acetonitrile to obtain 7 g of the desired M-4 as crystals.

Synthesis of P-1 M-4 (5 g, 16.4 mmol) obtained above and polymer MP-1 (3 g) were dispersed in 50 ml of acetonitrile and 20 ml of dimethylacetamide, and reacted at 80 ° C. for 10 hours. The solvent was distilled off from the reaction mixture at 120 ° C. under reduced pressure to obtain 7.8 g of a target polyalkylene oxide P-1 having a liquid crystalline side chain.

Example 2 Photoelectrochemical Battery 2-1. Preparation of Titanium Dioxide Dispersion Inside Volume Teflon Coated Inside 2
In a 00 ml stainless steel vessel, 15 g of titanium dioxide (Degussa P-25, Nippon Aerosil Co., Ltd.), 45 g of water, and a dispersant (Triton X, manufactured by Aldrich)
-100) of 1 g and zirconia beads having a diameter of 0.5 mm (manufactured by Nikkato Corporation) of 30 g were dispersed in a sand grinder mill (manufactured by Imex Corporation) at 1500 rpm for 2 hours. The zirconia beads were removed by filtration from the dispersion. The average particle size of the titanium dioxide in this case is 2.5
μm. The particle size at this time was measured with a master sizer manufactured by MALVERN.

2-2. Preparation of TiO ₂ electrode (electrode A) adsorbing dyes Conductive glass coated with fluorine-doped tin oxide (TCO glass-U manufactured by Asahi Glass Co., Ltd., 20 mm × 20 m
m), the above dispersion was applied to the conductive surface side using a glass rod. At this time, an adhesive tape was stretched on a part (3 mm from the end) on the conductive surface side to form a spacer, and glass was lined up so that the adhesive tape came to both ends, and applied eight at a time. After application, peel off the adhesive tape,
Air dried for 1 day at room temperature. Next, this glass was placed in an electric furnace (muffle furnace FP-32 manufactured by Yamato Scientific Co., Ltd.),
For 30 minutes. After taking out the glass and cooling, a solution of the dye (Exemplary Compound R-1) in ethanol (3 ×
10 ^-4 mol / liter) for 3 hours. The glass on which the dye was dyed was immersed in 4-tert-butylpyridine for 15 minutes, washed with ethanol and air-dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of the semiconductor fine particles was 20 g / m ² . The surface resistance of the conductive glass was about 30Ω / □.

2-3. Preparation of Photoelectrochemical Cell The dye-sensitized TiO ₂ electrode substrate (1 cm × 1 cm) prepared as described above was placed on the electrolyte composition of the present invention or the electrolyte composition (E- 102
To E-112) (acetonitrile was the same mass as the electrolyte composition), and acetonitrile was distilled off at 60 ° C. under reduced pressure while penetrating the TiO ₂ electrode. Platinum-deposited glass of the same size is superimposed on these electrodes, and a photoelectrochemical cell (samples B-102 to
B-112). In addition, an electrolytic solution using a solvent (Table 1)
E-101) is the same dye-sensitized TiO ₂ as described above.
After stacking platinum-deposited glass of the same size as the electrode on an electrode substrate (2 cm × 2 cm), an electrolytic solution is impregnated into the gap between the two glasses by using capillary action, and a photoelectrochemical cell (sample B- 101) was produced.

According to this embodiment, as shown in FIG. 2, the conductive glass 1 (the conductive layer 3 is provided on the glass 2), the photosensitive layer 4 (the TiO ₂ layer having a dye adsorbed thereon), the electrolyte A photoelectrochemical cell in which the layer 5, the platinum layer 6 serving as a counter electrode, and the glass 7 were sequentially stacked was produced.

[0163]

[Table 1]

[0164]

Embedded image

2-4. Measurement of photoelectric conversion efficiency A 500 W xenon lamp (made by Ushio) was used for AM1.
Simulated sunlight free from ultraviolet rays was generated by passing through a 5 filter (manufactured by Oriel) and a sharp cut filter (Kenko L-41), and the intensity of the light was adjusted to 100 mW / cm ² .

An alligator clip was connected to the conductive glass and the platinum-deposited glass of the photoelectrochemical cell, respectively.
Simulated sunlight was irradiated at 0 ° C., and the generated electricity was measured with a current / voltage measuring device (Keisley SMU238 type). The open-circuit voltage (Voc), short-circuit current density (Jsc), and form factor (F
F) [= maximum output / (open circuit voltage × short circuit current)], and conversion efficiency (η) and reduction rate of short circuit current density after aging for 400 hours under constant temperature and constant humidity (60 ° C., 70% RH). The results are collectively shown in Table 2.

[0167]

[Table 2]

A photoelectrochemical cell (sample B-101) using a comparative electrolyte using a solvent has very poor durability because the solvent is volatilized. Further, a molten salt RE-
1. Batteries using RE-2 (Samples B-102, B-
No. 103) has a small deterioration over time, but the photoelectric conversion performance is not sufficient. On the other hand, the battery using the electrolyte composition of the present invention has short-circuit current density, initial performance such as conversion efficiency,
Excellent in both durability. Such an effect was observed when any of the dyes was used.

(Example 3) Lithium secondary battery 3-1. Preparation of Positive Electrode Sheet As a positive electrode active material, 43 parts by mass of LiCoO ₂ , 2 parts by mass of flaky graphite, 2 parts by mass of acetylene black, and 3 parts by mass of polyacrylonitrile as a binder were added, and kneaded with 100 parts by mass of acrylonitrile as a medium. The obtained slurry was applied to an aluminum foil having a thickness of 20 μm using an extrusion coating machine, dried, compression-molded by a calender press, and an aluminum lead plate was welded to an end portion to form a thick plate. A positive electrode sheet having a thickness of 95 μm, a width of 54 mm and a length of 49 mm was produced.

3-2. Preparation of Negative Electrode Sheet 43 parts by mass of a mesoface pitch-based carbon material (Petoka) as a negative electrode active material, 2 parts by mass of acetylene black and 2 parts by mass of graphite as a conductive agent were mixed, and polyacrylonitrile 3 was used as a binder. Add parts by weight,
A negative electrode mixture slurry was obtained by kneading with 100 parts by mass of N-methylpyrrolidone as a medium. Negative mix slurry with thickness 1
A 0-μm copper foil was applied using an extrusion-type coating machine, dried, and compression-molded by a calender press to produce a negative electrode sheet having a thickness of 46 μm, a width of 55 mm and a length of 50 mm. After welding a lead plate made of nickel to the end of the negative electrode sheet, 230 ° C. in dry air having a dew point of −40 ° C. or less.
For 1 hour. The heat treatment was performed using a far-infrared heater.

3-3. Preparation of Sheet Battery The negative electrode sheet and the positive electrode sheet were each dehydrated and dried at 230 ° C. for 30 minutes in dry air having a dew point of −40 ° C. or less. In a dry atmosphere, a dehydrated and dried positive electrode sheet having a width of 54 mm × length 49 mm, a separator (polyethylene porous film) cut to a width of 60 mm × length 60 mm, and a nonwoven fabric are laminated, and the composition shown in Table 3 below is placed on the nonwoven fabric. A solution prepared by dissolving the above electrolyte composition (E-202 to 212) in the same amount of acetonitrile was applied, and acetonitrile was distilled off at 50 ° C. under reduced pressure. In addition, the electrolyte solution (E-201) using the solvent was directly permeated into the nonwoven fabric. A dehydrated and dried negative electrode sheet having a width of 55 mm and a length of 50 mm is laminated thereon, and polyethylene (50 μm) -polyethylene terephthalate (5
(0 μm) using an exterior material made of a laminated film, and four edges were heat-sealed under vacuum to form a sheet-type battery (samples B-201 to B-212).

According to the present embodiment, as shown in FIG. 3, a sheet-type battery in which a negative electrode sheet 33 having a negative electrode terminal 35, a polymer solid electrolyte 32, and a positive electrode sheet 31 having a positive electrode terminal 34 are sequentially laminated. Made.

[0173]

[Table 3]

3-4. Evaluation of Battery Performance For the sheet-type battery manufactured by the above method, charge and discharge were repeated 30 times under the conditions of a current density of 1.3 mA / cm ² , a charge end voltage of 4.2 V, and a discharge end voltage of 2.6 V.
The discharge capacity at the cycle was determined. This was examined for five batteries of the same prescription, and the average was taken as the capacity of the battery. Thus, the capacity of each battery was obtained, and the relative capacity to Sample B-201 was obtained. Further, the discharge capacity at the 200th cycle of each battery was determined,
The ratio to the discharge capacity at the cycle was calculated and expressed as the cycle capacity. Table 4 shows the respective values.

[0175]

[Table 4]

From the above results, it can be seen that the electrolyte composition of the present invention has improved cycleability without a large decrease in capacity.

[0177]

According to the present invention, there is provided a polymer liquid crystalline electrolyte composition which does not substantially volatilize and has excellent charge transporting ability. The present invention can provide an electrochemical cell excellent in durability, a photoelectrochemical cell excellent in durability and photoelectric conversion characteristics, and a nonaqueous secondary battery excellent in cycle characteristics without lowering the battery capacity.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a photoelectric conversion element of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a photoelectrochemical cell manufactured in Example 2.

FIG. 3 is a schematic diagram of a sheet-type battery manufactured in Example 3.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 conductive glass 2 glass 3 conductive layer 4 photosensitive layer (TiO ₂ layer with dye adsorbed thereon) 5 electrolyte layer 6 platinum layer 7 glass 10 photoelectric conversion element 12 conductive layer 14 undercoat layer 16 photosensitive layer 18 charge transfer layer 20 counter electrode conductive layer Reference Signs List 24 semiconductor layer 26 substrate 28 substrate s semiconductor fine particles d dye t charge transport material 31 positive electrode sheet 32 polymer solid electrolyte 33 negative electrode sheet 34 positive electrode terminal 35 negative electrode terminal

Claims (10)

[Claims] 1. A polyalkylene oxide having a side chain having a cation site or an anion site in a polyalkylene oxide main chain and a counter ion of the side chain, wherein the side chain or its counter ion is liquid crystalline. An electrolyte composition characterized by containing: 2. The electrolyte composition according to claim 1, wherein the polyalkylene oxide has a structure represented by the following formula (I). Embedded image (In the formula (I), A represents a substituent having an anion site or a cation site, Y represents a counter ion of A, and at least one of A and Y is liquid crystalline.) 3. The electrolyte composition according to claim 1, wherein the polyalkylene oxide has a structure represented by the following formula (II). Embedded image (In the formula (II), R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.) 4. The electrolyte composition according to claim 1, wherein the side chain is a liquid crystalline anion. 5. The electrolyte composition according to claim 1, wherein the side chain is a liquid crystalline cation. 6. The electrolyte composition according to claim 4, wherein the counter ion of the side chain is an alkali metal ion. 7. The method according to claim 1, wherein the counter ion of the side chain is iodine anion, sulfonamide, disulfonimide, N
-At least one kind selected from acylsulfonamide, carboxylic acid, sulfonic acid, alcohol, active methylene, and active methine is a dissociated anion.
8. The electrolyte composition according to item 1. 8. An electrochemical cell comprising the electrolyte composition according to claim 1. Description: 9. Photoelectrochemistry comprising a charge transfer layer containing the electrolyte composition according to claim 1, a photosensitive layer containing a semiconductor sensitized with a dye, and a counter electrode. battery. 10. A non-aqueous secondary battery comprising the electrolyte composition according to claim 1. Description: