JP3516290B2 - Polymer solid electrolyte and electrochemical device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymer solid electrolyte, and more particularly to a polymer electrolyte having high ion conductivity and little change with time, an improved electrochemical device using the same, and an improved solid electrolyte. Next battery.

[0002]

2. Description of the Related Art In recent years, there has been remarkable progress in making electronic devices smaller, lighter, and thinner. In the OA field, in particular, the size of electronic devices has been reduced from desktop type to laptop type and notebook type. In addition, the field of new small electronic devices such as electronic notebooks and electronic still cameras has emerged.In addition to the miniaturization of conventional hard disks and floppy disks, the development of new small memory cards, such as memory cards, is also underway. . In the wave of downsizing, lightening, and thinning of such electronic devices, secondary batteries supporting these electric powers are also required to have high performance such as high energy density, high voltage, and high output. In such a request,
As a thin, high-energy density battery, a sheet-type secondary battery using a polymer solid electrolyte as an electrolyte has been developed. Secondary batteries using solid polymer electrolytes have many features not found in conventional cylindrical and prismatic batteries, such as high reliability due to no liquid leakage, flexible shape, large area, and extremely thin shape. ing. However, secondary batteries using polymer solid electrolytes have not yet been put to practical use. One of the major factors is that the interface resistance between the electrode and the polymer solid electrolyte is lower than the resistance of the electrode and the polymer solid electrolyte bulk. Because it ’s big,
It has been pointed out that the internal impedance is high, charging and discharging with a large current is difficult, and the interface resistance increases with time as compared with a normal secondary battery using an electrolytic solution. In order to reduce the interface resistance, for example, JP-A-5-290615 discloses a method of depositing a polymer solid electrolyte on an electrode by a cluster ion beam method. However, the solid polymer electrolyte produced in this manner has an ionic conductivity that is at least two orders of magnitude lower than that of the electrolytic solution, and has low productivity. Japanese Patent Application Laid-Open No. H5-115199 proposes that an electrode contains an electrolyte and is bonded to a solid polymer electrolyte. However, since the electrolyte contained in the electrode is absorbed by the solid polymer electrolyte, the interface resistance increases with the passage of time.

JP-A-63-94501 discloses a polymer solid electrolyte obtained by curing a composition comprising an acryloyl-modified polyalkylene oxide, an electrolyte salt, and a solvent by irradiating the composition with ultraviolet rays. Since this polymer solid electrolyte has high ionic conductivity and the precursor before irradiation with ultraviolet rays is a liquid, the precursor is cast on an electrode,
It was expected that the interface close to the state between the electrolyte and the electrode could be prepared by irradiating ultraviolet rays to prepare the polymer solid electrolyte. However, the interfacial resistance between the polymer solid electrolyte and the electrode is higher than expected and tends to increase with time, and the strength of the polymer solid electrolyte is low. It was not performance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrochemical device using a polymer solid electrolyte having a low internal resistance and having a small increase in internal resistance over time, especially a secondary device. It is to provide a battery.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to reduce the interfacial resistance between an electrode and a solid polymer electrolyte and made detailed observations. As a result, at least the electrolyte salt and the polymerizable monomer and / or It has been found that in a solid polymer electrolyte prepared by polymerizing a mixture of a polymerizable oligomer and a polymerizable monomer and / or a polymerizable oligomer, an unreacted polymerizable monomer and / or polymerizable oligomer greatly contributes to interface resistance. That is, if there is a large amount of unreacted polymerizable monomer and / or polymerizable oligomer in the polymer matrix of the solid polymer electrolyte,
Electrode reaction is inhibited, the internal resistance of the electrochemical device has found that high.

In the solid polymer electrolyte of the present invention, the polymer matrix of the solid polymer electrolyte contains 30% by weight of unreacted polymerizable monomers and / or polymerizable oligomers.
The following is preferably 20 wt% or less. If the amount of the unreacted polymerizable monomer and / or polymerizable oligomer is 30% by weight or more, the interface resistance between the electrode and the solid polymer electrolyte increases, which is not preferable. As a method for detecting unreacted polymerizable monomers and / or polymerizable oligomers in the polymer matrix of the polymer solid electrolyte, various methods such as Soxhlet extraction and ultrasonic extraction can be used to detect residual monomers and oligomers in the polymer matrix of the polymer solid electrolyte. It can be extracted by an extraction method and detected using an analytical method such as gas chromatography, high performance liquid chromatography, and supercritical chromatography.

In order to reduce the amount of unreacted polymerizable monomer and / or polymerizable oligomer in the polymer matrix of the solid polymer electrolyte to 30% by weight or less, it is preferable to complete the polymerization reaction promptly and reliably. As the polymerization reaction, polymerization by irradiation with actinic rays such as ultraviolet rays, electron beams, X-rays, and γ-rays is faster than other polymerization methods such as thermal polymerization, and there is little deterioration of the solid polymer electrolyte. Irradiation with ultraviolet rays is particularly preferable in consideration of simplicity and safety of the apparatus. In the case of ultraviolet irradiation, the irradiation intensity is 20 mW / cm ² or more, preferably 30 mW / c.
When it is at least m ^2, unreacted polymerizable monomers and / or polymerizable oligomers can be reduced, and a solid polymer electrolyte can be produced quickly. In the case of ultraviolet irradiation, when the irradiation intensity is 20 mW / cm ² or less, the amount of unreacted polymerizable monomers and / or polymerizable oligomers increases, and the interface resistance between the electrode and the solid polymer electrolyte increases. A method of extracting unreacted polymerizable monomers and / or polymerizable oligomers with a suitable solvent is also conceivable.However, swelling of the polymer solid electrolyte by the extraction solvent causes separation of the interface between the electrode and the polymer solid electrolyte, It is not preferable because removal becomes a problem.

The solid polymer electrolyte used in the electrochemical device of the present invention is prepared from at least a polymerizable monomer or oligomer and an electrolyte salt. In addition, a polymer solid electrolyte gel prepared by adding a non-aqueous solvent to a polymerizable monomer or oligomer and an electrolyte salt has an ionic conductivity comparable to that of an electrolytic solution, and is therefore most preferable for producing an electrochemical device having a low internal resistance. Things. The polymer solid electrolyte of the present invention may be used alone in an electrochemical device without any problem, but may be used in combination with a separator in order to completely prevent a short circuit. If necessary, a polymerization initiator, a storage stabilizer or a thixotropic agent may be added to the composition.

[0009] As the polymerizable monomer or oligomer used in the present invention, an oxygen atom in its molecule, a nitrogen atom,
It is intended to include hetero atoms other than carbon, such as sulfur atom. In a solid electrolyte (viscoelastic body) obtained by dissolving a polymerizable compound containing these heteroatoms in a non-aqueous electrolyte and performing a polymerization reaction, the heteroatoms other than carbon promote ionization of an electrolyte salt, It is considered that the ionic conductivity of the solid electrolyte is improved and also the function of improving the strength of the solid electrolyte is improved. The type of the polymerizable compound used in the present invention is not particularly limited, and includes those obtained by causing a polymerization reaction such as thermal polymerization and actinic ray polymerization. Is preferred. Examples of the thermal polymerization reaction include a polymerization reaction with an epoxy group or an acrylate group in addition to the urethane reaction, and the urethane reaction is preferable. Examples of the actinic ray polymerization reaction include a polymerization reaction with an unsaturated carboxylic acid ester, a polyene / polythiol mixture and a crosslinkable macromer (organic silane, polyisothianaphthene, etc.).
Is a reaction by polythiol mixture. Hereinafter, the polymerization reaction of an unsaturated carboxylic acid ester, the polymerization reaction of a polyene / polythiol mixture, and the polyurethane conversion reaction, which are particularly excellent as polymerization reactions in an electrolytic solution, will be described in detail. In this specification, (meth) acrylate means acrylate or methacrylate, and (meth) acryloyl group means acryloyl group or methacryloyl group.

The polymerization reaction in the non-aqueous electrolyte for obtaining the solid electrolyte of the present invention is preferably an active light polymerization reaction which is a low-temperature process in order to avoid thermal decomposition of the electrolyte. As the actinic ray-polymerizable compound, (meth) acrylate,
Examples include a combination of a polyene and a polythiol.
(Meth) (meth) acrylates of single pipe capacity and polyfunctional thereof include acrylate. Examples of single-tube acrylates include alkyl (meth) acrylate [methyl (meth) acrylate, butyl (meth) acrylate, trifluoroethyl (meth) acrylate, etc.], alicyclic (meth) acrylate [tetrahydrofurfuryl (meth) acrylate Etc.], hydroxyalkyl (meth) acrylate [hydroxyethyl acrylate, hydroxypropyl acrylate, etc.], hydroxypolyoxyalkylene (oxyalkylene group preferably has 1 to 4 carbon atoms)
(Meth) acrylate [hydroxypolyoxyethylene (meth) acrylate, hydroxypolyoxypropylene (meth) acrylate, etc.] and alkoxy (alkoxy group preferably has 1 to 4 carbon atoms) (meth) acrylate [methoxyethyl acrylate, ethoxyethyl Acrylate, phenoxyethyl acrylate, etc.]. Examples of polyfunctional (meth) acrylates include U
V, EB curing technology (issued by Sogo Gijutsu Center) 14
Among the photo-heavy monomers and photopolymerizable prepolymers described on pages 2 to 152, tri- or higher functional monomers, prepolymers [trimethylolpropane tri (meth) acrylate,
Pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like are preferred.

Among the acrylates, a compound represented by the following formula (I) having a molecular weight of less than 500 and a structure represented by the formula (II) are particularly preferred.

[0012]

Embedded image (Where R₁Is a hydrogen atom or a methyl group, R_TwoIs hydrocarbon
Group or group containing a heterocyclic ring, n represents an integer of 1 or more)

[0013]

Embedded image (Wherein, R ₃ is a hydrogen atom or a methyl group, R ₄ represents a group containing a heterocyclic ring)

In the formula (I), R ₂ represents a hydrocarbon group or a group containing a heterocyclic ring. In this case, the hydrocarbon group includes aliphatic and aromatic hydrocarbon groups. Examples of the aliphatic hydrocarbon group include those having 1 to 1 carbon atoms such as methyl, ethyl, propyl, butyl, hexyl and octyl.
0, and preferably those of 1 to 5. Further, as the aromatic hydrocarbon group, phenyl, tolyl, xylyl,
Examples include naphthyl, benzyl, phenethyl and the like. Examples of the group containing a heterocyclic ring include various heterocyclic groups containing a heteroatom such as oxygen, nitrogen, and sulfur. Examples of such a group include furfuryl and tetrahydrofurfuryl. Specific examples of the acrylate represented by the general formula (I) include, for example, alkylethylene glycol acrylate [methylethylene glycol acrylate, ethylethylene glycol acrylate, propylethylene glycol acrylate, phenylethylene glycol acrylate, etc.], alkylpropylene glycol acrylate [ ethyl glycol acrylate, and butyl propylene glycol acrylate,
Alkylene glycol acrylates having a heterocyclic ring [furfuryl ethylene glycol acrylate, tetrahydrofurfuryl ethylene glycol acrylate, furfuryl propylene glycol acrylate, tetrahydrofurfuryl propylene glycol acrylate, etc.] may be mentioned. The molecular weight of these acrylates represented by the general formula (I) is usually less than 500, but is more preferably 300 or less. Non-aqueous solvent from the solid electrolyte molecular weight can be obtained in more than 500 acrylate is likely to exude.

The heterocycle contained in the (meth) acrylate represented by the general formula (II) is not particularly limited. In this case, examples of the group containing a heterocycle include a residue of a heterocycle containing a heteroatom such as oxygen, nitrogen, and sulfur, such as a furfuryl group and a tetrahydrofurfuryl group. Examples of the (meth) acrylate represented by the general formula (II) include furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and the like. Of these, furfuryl acrylate and tetrahydrofurfuryl acrylate are preferred. The compound represented by formula (I) or (II) may be used alone, or two or more kinds may be used in combination.

By using a polyfunctional unsaturated carboxylic acid ester in combination with the compound represented by the general formula (I) or (II), a solid electrolyte ideal in both elastic modulus and ionic conductivity can be obtained. . The polyfunctional unsaturated carboxylic acid esters include those having two or more (meth) acryloyl groups. Preferable specific examples thereof include dimers or prepolymers of the photopolymerizable monomers and photopolymerizable prepolymers described in “UV, EB Curing Technology” (published by Sogo Gijutsu Center), pp. 142-152. polymer [diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate,
Trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc.]
However, trifunctional (meth) acrylate is most preferable in that it provides a solid electrolyte having excellent liquid retention, ionic conductivity, and strength. The proportion of the compound represented by the general formulas (I) and (II) or the unsaturated carboxylic acid ester containing the compound as a main component is 50% by weight or less based on the non-aqueous electrolyte.
Below, preferably 5 to 40% by weight, more preferably 10% by weight.
~ 30% by weight is good. Outside this range, the ionic conductivity and strength of the solid electrolyte are reduced. Formulas (I) and (I)
When a polyfunctional unsaturated carboxylic acid ester is used in combination with the compound of I), the amount of the polyfunctional unsaturated carboxylic acid ester added is 4% by weight or less, preferably 0.05 to 2% by weight, based on the non-aqueous electrolyte. %, Especially when a trifunctional unsaturated carboxylic acid ester is used in combination, a small addition amount of 2% by weight or less, preferably 0.05 to 0.5% by weight is excellent in ionic conductivity and strength. solid electrolyte can be obtained. By using such a polyfunctional unsaturated carboxylic acid ester in combination, it is possible to obtain a solid electrolyte having better ionic conductivity and strength. On the other hand, if the combined amount of the polyfunctional unsaturated carboxylic acid ester is too large, the obtained solid electrolyte does not show the properties as a viscoelastic body, lacks flexibility, and is liable to crack especially against external stress.

Examples of the polymerization initiator of the compounds represented by the general formulas (I) and (II) or the unsaturated carboxylic acid ester containing these as a main component include carbonyl compounds, benzoins (benzoin, benzoin methyl ether, benzoin ethyl ether). , Ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, α-methylbenzoin, α
-Phenylbenzoin, etc.), anthraquinones (anthraquinone, methylanthraquinone, chloranthraquinone, etc.), other compounds (benzyl, diacetyl, acetophenone, benzophenone, methylbenzoylformate, etc.), sulfur compounds (diphenylsulfide, dithiocarbamate, etc.), many Condensed ring hydrocarbon halides (such as α-chloromethylnaphthalene), dyes (such as acrylflavin and fluorescein), metal salts (such as iron chloride and silver chloride), and onium salts (such as P-methoxybenzenediazonium and hexafluorophos) Photoinitiators such as fate, diphenyliodonium, and triphenylsulfonium). These can be used alone or as a mixture of two or more. Preferred photopolymerization photoopening agents are carbonyl compounds, sulfur compounds and onium salts. If necessary, a thermal polymerization initiator (azobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, ethyl methyl ketone peroxide, etc.) can be used in combination, and dimethylaniline, cobalt naphthenate, sulfinic acid, mercaptan, etc. Can be used in combination. Further, sensitizers, can be used in combination if necessary also storage stabilizer. Specific examples of the sensitizer and the storage stabilizer include sensitizers described in “UV, EB curing technology (published by Sogo Gijutsu Center)”, pp. 158-159.
Among the storage stabilizers, as the former, urea nitrile compounds (N, N-disubstituted-P-aminobenzonitrile and the like) and phosphorus compounds (tri-n-butylphosphine and the like) are preferable.
The latter, quaternary ammonium chloride, benzothiazole, hydroquinone is preferred. The amount of the polymerization initiator to be used is generally 0.1 to 10% by weight, preferably 0.5 to 7% by weight, based on all unsaturated carboxylic acid esters. Outside this range, an appropriate reactivity cannot be obtained. The use amount of the sensitizer and the storage stabilizer is usually 0.1 to 5 parts by weight based on 100 parts by weight of the total unsaturated carboxylic acid ester.

The solidification of the electrolytic solution according to the present invention is carried out by placing a non-aqueous electrolytic solution containing a compound represented by the above general formula (I) or (II) or an unsaturated carboxylic acid ester containing the compound as a main component in a sealed container. It is achieved by injecting or coating on a support (for example, film, metal, metal oxide, glass, etc.) and then polymerizing with heat or actinic rays. As the active ray, usually, light, ultraviolet light, electron beam, X
Lines can be used. Of these, preferably, 100 to
It is an active light beam having a main wavelength of 800 nm.

The polymerization reaction of a mixture of polyene / polythiol is basically as follows.

[0020]

[Formula 3] ^{RSH → RS · + H · RS} · + CH 2 = CH-CH 2 R '→ RS-CH 2 -CH-
CH ₂ R ′ RSH → RS—CH ₂ —CH ₂ —CH ₂ R ′ + RS ^. (In the above formula, R and R ′ are organic groups such as an alkyl group.) Examples of the polyene include polyallyl ether compounds and polyallyl Ester compounds are exemplified. Examples of the polyallyl ether compound include compounds obtained by adding an epoxy compound (such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epihalohydrin, and allyl glycidyl ether) to a substituted or unsubstituted allyl alcohol. Of these, preferred are compounds obtained by adding ethylene oxide and propylene oxide to substituted and unsubstituted allyl alcohol. Examples of the polyallyl ester compound include a reaction product of an allyl alcohol or the above-mentioned polyallyl ether compound with a carboxylic acid. Examples of carboxylic acids include aliphatic, cycloaliphatic, and aromatic mono- and polycarboxylic acids (such as acetic acid, propionic acid, butyric acid, octanoic acid, lauric acid, stearic acid, oleic acid, and benzoic acid). Acid, (C 1
20); adipic acid, and dicarboxylic acids such as phthalic acid). Preferred among these are reaction products of a polyallyl ether compound and a polycarboxylic acid. As polythiol, liquid polysulfide;
Aliphatic polythiol compounds of cycloaliphatic and aromatic; mercaptocarboxylic acid esters. As the liquid polysulfide Thiokol LP series (east Thiokol Co., Ltd.) and the like. Among preferred are average molecular weight is of 400 or less. Examples of the aliphatic, alicyclic and aromatic polythiol compounds include methane (di) thiol and ethane (di) thiol. The mercaptocarboxylic acid ester, compounds obtained by transesterification of an esterification reaction or mercaptocarboxylic acid alkyl esters with polyhydric alcohols and mercapto carboxylic acids and polyhydric alcohols. Examples of mercaptocarboxylic acids include 2-mercaptoacetic acid and 3-mercaptopropionic acid.
Examples of polyhydric alcohols include ethylene glycol, trimethylolpropane, glycerin, pentaerythritol, sucrose, and alkylene oxide adducts thereof (ethylene oxide, propylene oxide adduct,
Butylene oxide adduct). Preferred polyhydric alcohols are trihydric or higher polyhydric alcohols that do not contain an alkylene oxide adduct.
Examples of mercaptocarboxylic acid alkyl esters include:
Examples thereof include 2-mercaptoacetic acid ethyl ester and 3-mercaptopropionic acid methyl ester. Preferred among the polythiol is a liquid polysulfide and mercapto carboxylic acid ester. polyethylene/
As the polymerization initiator for the reaction mixture of the polythiol, the same polymerization initiator as described for the polymerization of the unsaturated carboxylic acid ester is used.

The electrolyte salt used in the present invention is not particularly limited as long as it is used as a normal electrolyte.
For example, LiBR ₄ (R is a phenyl group, an alkyl group),
_{LiPF 6, LiSbF 6, LiAsF 6} , LiBF 4, L
_{iClO 4, CF 3 SO 3 Li} , (CF 3 SO 2) 2 NLi,
(CF ₃ SO ₂ ) ₃ CLi, C ₆ F ₉ SO ₃ Li, C ₈ F ₁₇ SO
₃ Li, LiAlCl _4, lithium tetrakis [3,5
Bis (trifluoromethyl) phenyl] borate and the like can be used alone or as a mixture. Preferably, CF ₃ SO ₃ Li (CF ₃ SO ₂ ) ₂ NLi, (CF ₃ SO ₂ ) ₃
It is an electrolyte of a sulfonic acid anion such as CLi, C ₆ F ₉ SO ₃ Li, and C ₈ F ₁₇ SO ₃ Li.

As the non-aqueous solvent used in the present invention, carbonate solvents (propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate,
Diethyl carbonate), amide solvent (N-methylformamide, N-ethylformamide, N, N-dimethylformamide, N-methylacetamide, N-ethylacetamide, N-methylpyrrolidinone), lactone solvent (γ-butyllactone, γ- valerolactone, .delta.-valerolactone, 3-methyl-1,3-oxazolidin-2
ON), alcohol solvents (ethylene glycol, propylene glycol, glycerin, methyl cellosolve,
1,2 butanediol, 1,3 butanediol, 1,4
Butanediol, diglycerin, polyoxyalkylene glycol cyclohexanediol, xylene glycol, etc.), ether solvents (methylal, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy-)
2-methoxyethane, alkoxypolyalkylene ether, etc.), nitrile solvent (benzonitrile, acetonitrile, 3-methoxypropionitrile, etc.), phosphoric acid and phosphate ester solvents (normal phosphoric acid, metaphosphoric acid, pyrophosphoric acid, pyrophosphoric acid, polyphosphoric acid, phosphorous acid) , Trimethyl phosphate, etc.), 2-imidazolidinones (1,3-dimethyl-2-imidazolidinone, etc.), pyrrolidones, sulfolane solvents (sulfolane,
Tetramethylene sulfolane), a furan solvent (tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethoxytetrahydrofuran), dioxolane, dioxane, dichloroethane, or a mixture of two or more solvents can be used. Of these, preferred are carbonates, ethers and furan solvents. As the separator, one having low resistance to ion movement of the electrolyte solution and having excellent solution retention properties is used, for example, one or more of glass, polyester, polytetrafluoroethylene, polypropylene, and polyethylene. It includes nonwoven or woven fabric selected from a material. Since the polymer solid electrolyte of the present invention can lower the interface resistance with the electrode, it is used for an electrochemical device utilizing an electrochemical reaction such as a primary battery, a secondary battery, a sensor, an electrochromic device, and an electrochemical FET. it can exhibit a large effect when applied to particular secondary batteries.

The electrodes used in the electrochemical device of the present invention are molded by using a binder and a conductive agent as required. Examples of the binder include, but are not limited to, organic fluoropolymers such as polytetrafluoroethylene and polyvinylidene fluoride, polyolefins such as polyethylene and polypropylene, and soluble conductive polymers such as polyaniline and polyalkylthiophene. As the conductive agent, graphite, carbon black, acetylene black,
Conductive carbon such as Ketjen black; metals or alloys such as nickel, copper, titanium, and stainless steel; conductive oxides such as titanium oxide and indium oxide; and conductive polymer materials such as polypyrrole. preferred can improve conductivity with a small amount of addition amount gender carbon.

The secondary battery of the present invention basically comprises a positive electrode, a negative electrode and a solid polymer electrolyte, and may use a separator if necessary.

The positive electrode active material of the secondary battery of the present invention can be exemplified by an inorganic active material, an organic active material, and a composite thereof. The inorganic active material or a composite of the inorganic active material and the organic active material is exemplified. body, particularly the energy density is significantly preferred.
Examples of the inorganic active _{materials, MnO 2, Mn 2 O 3} , CoO 2,
NiO ₂ , TiO ₂ , V ₂ O ₅ , V ₃ O ₈ , Cr ₂ O ₃ , Fe
Metal oxides such as ₂ (SO ₄ ) ₃ , Fe ₂ (MoO ₂ ) ₃ and Fe ₂ (WO ₂ ) ₃ , metal sulfides such as TiS ₂ , MoS ₂ and FeS, and composite oxides of these compounds and lithium Is mentioned. Examples of the organic active material include conductive polymers such as polyacetylene, polyaniline, polypyrrole, polythiophene, polyalkylthiophene, polycarbazole, polyazulene, and polydiphenylbenzine, and one or more composites selected from carbon bodies. be able to. As the negative electrode active material of the secondary battery of the present invention, lithium, an alkali metal such as sodium, aluminum, lead, silicon, an alloy of lithium and a metal such as magnesium, polypyridine, polyacetylene, polythiophene or a derivative thereof can be cation-doped. Examples thereof include a conductive polymer, a carbon body capable of storing lithium, and a metal oxide such as SnO ₂ and TiO _2. Among them, a carbon body is most preferable in terms of cycle life and energy density. Examples of the carbon body include natural graphite, coal coke, and petroleum coke, as well as carbon bodies obtained by calcining pyrolytic carbon obtained from organic compounds, natural polymers, and synthetic polymers. Although the form of the secondary battery of the present invention is not particularly limited, it can be mounted on various forms of batteries such as coins, sheets, cylinders, and gums.

[0026]

【Example】

Example 1 45 parts by weight of natural graphite having an average particle diameter of 10 μm, 45 parts by weight of pitch coke having an average particle diameter of 8 μm, and 10 parts by weight of poly (vinylidene fluoride) were mixed, and N-methylpyrrolidone was added and mixed to form a paste. I made it. This was applied to a copper foil of 20 μm, dried, and the thickness of the electrode active material layer was reduced to 60 μm.
Was prepared. The carbon electrode is 1.5M LiN
0V constant voltage charging was performed in an electrolytic solution in which (CF ₃ SO ₂ ) ₂ was dissolved in a 1: 1 (volume ratio) mixed solvent of ethylene carbonate and diethyl carbonate. Using this electrode as a working electrode, a beaker cell was prepared using lithium as a counter electrode.
A composition obtained by mixing 13.8 parts by weight of ethoxydiethylene glycol acrylate, 0.2 parts by weight of trimethylolpropane triacrylate, and 86 parts by weight of the above electrolyte and 0.01 parts by weight of benzoin isopropyl ether was poured into a beaker cell. Thereafter, ultraviolet rays having an illuminance of 70 mW / cm ² were irradiated for 30 seconds to cause a polymerization reaction, and the carbon electrode and the solid polymer electrolyte were combined. 1.4 carbon electrodes
mA / cm ² , 0V, constant current constant voltage charge in 3 hours,
In 1.4 mA / cm ² or 2.8 mA / cm ² 0.8
Discharge was performed to V. The above charge and discharge conditions were repeated, and the energy density of the carbon electrode at the fifth cycle was measured. The results are shown in Table 1.

Comparative Example 1 In Example 1, ultraviolet rays having an illuminance of 10 mW / cm ²
A beaker cell was prepared in the same manner as in Example 1 except that irradiation was performed for one minute, and the energy density of the carbon electrode was measured. The results are shown in Table 1.

Comparative Example 2 A beaker cell was prepared in the same manner as in Example 1 except that ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 3 minutes, and the energy density of the carbon electrode was measured. The results are shown in Table 1.

[0029]

[Table 1]

[0030] were mixed in a weight ratio of Example 2 V ₂ O ₅ and polyaniline 85:15,
Add N-methylpyrrolidone to make a paste,
m, and dried to form an electrode having an electrode active material layer having a thickness of 80 μm. The electrode positive, using a carbon electrode of Example 1 in the negative electrode, to prepare a beaker cell. 13.8 parts by weight of furfuryl acrylate and 0.1 part by weight.
86 parts by weight of an electrolyte obtained by dissolving 2 parts by weight of trimethylolpropane triacrylate and 1.5 M LiPF ₆ in a 1: 1 (volume ratio) mixed solvent of ethylene carbonate and diethyl carbonate, and 0.01 parts by weight of benzoin isopropyl ether After pouring the mixed composition into a beaker cell, it was irradiated with ultraviolet rays having an illuminance of 30 mW / cm ² for 30 seconds to cause a polymerization reaction. 1.2 mA / cm ² ,
3.7V, perform constant-current and constant-voltage charging in 3 hours, 1.2mA
It was discharged to 2.5V at / cm ^2. The above charge and discharge conditions were repeated, and the discharge capacity of the beaker cell at the 50th cycle was measured.

Comparative Example 3 A beaker cell was prepared in the same manner as in Example 2 except that ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 3 minutes, and the discharge capacity of the beaker cell was measured. These results are shown in Table 2.

[0032]

[Table 2]

[0033]

As described above in detail and specifically, according to the present invention, there is provided a polymer solid electrolyte capable of keeping the interface resistance with an electrode low, and a highly reliable electrochemical device is provided. Can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiyuki Osawa Ricoh Co., Ltd. 1-3-6 Nakamagome, Ota-ku, Tokyo (56) References JP-A 8-315857 (JP, A) JP 9-129246 (JP, A) JP-A-9-147920 (JP, A) WO 94/000889 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 2/00- 2/60 H01M 6 / 18,10 / 40

Claims (7)

(57) [Claims] 1. Non-aqueous electrolysis in which an electrolyte salt is dissolved in a non-aqueous solvent
Relative to the liquid 100 wt%, Table by formula (I) and (II)
Compound or unsaturated carboxylic acid containing the same as a main component
Mixing 10 to 30% by weight of ester, actinic ray polymerization reaction
A solid polymer electrolyte produced by
30% by weight of unreacted polymerizable monomer in the matrix
A polymer solid electrolyte characterized by the following. Embedded image (Wherein, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrocarbon
A group or a group containing a heterocyclic ring, and n represents an integer of 1 or more. (Wherein, _{R 3} is a hydrogen atom or a methyl group, _{R 4} is a heterocyclic ring
Represents a group containing) 2. Non-aqueous electrolysis in which an electrolyte salt is dissolved in a non-aqueous solvent.
Relative to the liquid 100 wt%, Table by formula (I) and (II)
Compound or unsaturated carboxylic acid containing the same as a main component
10 to 30% by weight of ester, and 4% by weight or less.
The polymer solid electrolyte according to claim 1, wherein a functional unsaturated carboxylic acid ester is used in combination and mixed. Embedded image (Wherein, _{R 1} represents a hydrogen atom or a methyl group, _{R 2} is a hydrocarbon
A group or a group containing a heterocyclic ring, and n represents an integer of 1 or more. (Wherein, _{R 3} is a hydrogen atom or a methyl group, _{R 4} is a heterocyclic ring
Represents a group containing) 3. 20 mW / cm ² UV light of the above illuminance
It is characterized by being produced by irradiation
The polymer solid electrolyte according to claim 1 or 2, wherein 4. The solid polymer electrolyte according to claim 1, further comprising a non-aqueous solvent. 5. An electrochemical device using the solid polymer electrolyte according to claim 1. Description: 6. A secondary battery using the solid polymer electrolyte according to claim 1. Description: The secondary battery according to claim 6, 7. negative electrode active material is characterized in that it is a carbon material.