JP2002033016A - Polymer solid electrolyte and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer solid electrolyte with high ionic conductivity, high electrochemical stability, and high stability in a charged state, and provide a secondary battery with high performance using the polymer solid electrolyte. SOLUTION: This polymer solid electrolyte contains a salt of Group Ia metal in the periodic table in a polymer compound having acid anhydride structure, and this secondary battery uses this polymer solid electrolyte.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a solid polymer electrolyte used for a primary battery, a secondary battery, a capacitor, and the like, and a secondary battery using the same. More specifically, the present invention relates to an acrylate or methacrylate polymer solid electrolyte excellent in storage stability and a secondary battery using the same.

[0002]

2. Description of the Related Art Conventionally, liquid electrolytes have been used for electrochemical devices such as primary batteries, secondary batteries, and capacitors. However, when a liquid electrolyte is used, there is a concern about leakage from a product container, and therefore, there has been a demand for an improvement for improving long-term reliability in using an electrochemical element.

As one improvement method, a method using a solid electrolyte instead of a liquid electrolyte has been studied.
If a solid electrolyte is used, there is no risk of liquid leakage, so that a highly reliable element can be provided, and there is also an advantage that the element itself can be reduced in size and weight.

In recent years, among solid electrolytes, polymer solid electrolytes have attracted attention and have been studied. The polymer solid electrolyte is
Because of its flexibility, it is estimated that it is possible to flexibly cope with a volume change occurring in the ion-electron exchange reaction process between the electrode and the electrolyte. Therefore, expectations for practical use are increasing.

As an example of such a solid polymer electrolyte, a composite of polyethylene oxide having a polyether structure and an alkali metal salt such as a lithium salt is known. JP-A-5-25353 discloses a cross-linked resin and an inorganic salt mainly composed of a polyoxyalkylene diester compound, a polymethoxyoxyalkylene ester compound, and a copolymer of an oxy compound having a double bond. A polymer solid electrolyte as a constituent component is described. Further, JP-A-6-223842 describes a polymer solid electrolyte comprising an organic polymer substance having a carbonate group as a functional group and a metal salt.

On the other hand, Japanese Patent Application Laid-Open No. 1-241764 discloses that a polycarbonate methacrylate resin obtained by polymerizing a methacrylic acid ester of a polycarbonate polyol has excellent properties as a polymer electrolyte material.

In general, since a solid electrolyte has a lower ionic conductivity than a liquid electrolyte, it is difficult to manufacture a battery having excellent charge / discharge characteristics. Therefore, it is necessary to coexist a carbonate compound or the like as a plasticizer in the solid electrolyte. Is being done. In addition, as the amounts of the plasticizer and the alkali metal salt retained in the solid electrolyte are increased, more excellent charge / discharge characteristics are exhibited. However, the solid polymer electrolyte containing these plasticizers may become liquefied when stored in a charged state depending on the kind thereof, particularly when LiPF ₆ is used as a metal salt. Therefore, in order to realize primary and secondary batteries that have excellent charge-discharge characteristics using a solid electrolyte and operate stably for a long period of time, high ionic conductivity, excellent electrochemical stability, and charging There is a demand for the appearance of a low-cost solid polymer electrolyte that is excellent in stability in a state.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a solid polymer electrolyte having high ionic conductivity, excellent electrochemical stability, and excellent stability in a charged state. To the purpose. Another object of the present invention is to provide a secondary battery using such a solid polymer electrolyte.

[0009]

SUMMARY OF THE INVENTION The present invention provides a polymer solid electrolyte comprising a polymer compound having an acid anhydride structure and a metal salt of Group Ia of the Periodic Table.

The polymer solid electrolyte in which the polymer compound having an acid anhydride structure is a polymer of a monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group, This is a preferred embodiment of the present invention.

A polymer solid electrolyte wherein the monomer having the acid anhydride structure and at least one group selected from acrylate and methacrylate groups is a compound represented by the general formula (1) or (2). Is a preferred embodiment of the present invention.

Embedded image (In the formula, R ^{1 to} R ⁶ represent a hydrogen atom or a monovalent organic group.)

Embedded image (Wherein, R ⁷ represents a hydrogen atom or a methyl group, and n is 1
Represents an integer of from 5 to 5. )

[0012] The polymer compound having an acid anhydride structure does not include an acid anhydride structure, a monomer containing at least one group selected from an acrylate group and a methacrylate group, and an acid anhydride structure. Acrylate groups and / or
Alternatively, a solid polymer electrolyte which is a copolymer with a monomer containing a methacrylate group is also a preferred embodiment of the present invention.

The above solid polymer electrolyte in which the metal salt of Group Ia of the periodic table is a lithium salt is a preferred embodiment of the present invention.

The above polymer solid electrolyte in which the polymer compound is a gel-like material holding a non-aqueous solvent is also a preferred embodiment of the present invention.

The present invention also provides a secondary battery containing the above solid polymer electrolyte.

Further, according to the present invention, there is provided a polymer solid electrolyte as described above, metallic lithium, a lithium-containing alloy, a carbon material capable of doping and undoping lithium ions, and a lithium material capable of doping and undoping lithium ions as a negative electrode active material. A negative electrode containing at least one selected from the group consisting of tin oxide, silicon capable of doping and undoping lithium ions, and titanium oxide capable of doping and undoping lithium ions; lithium and a transition metal as positive electrode active materials; And a positive electrode containing the composite oxide of the above.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Next, the respective components of the solid polymer electrolyte according to the present invention and a secondary battery using the same will be described. In this specification, acrylate and methacrylate are collectively referred to as (meth) acrylate.

The solid polymer electrolyte of the present invention is a solid polymer electrolyte having a metal compound of Group Ia of the periodic table in a polymer compound having an acid anhydride structure.

Polymer Compound Having Acid Anhydride Structure The polymer compound having an acid anhydride structure which can be used in the present invention is a compound having an acid anhydride structure in the main or side chain of a polymer molecule. Any polymer may be used as long as the polymer has Particularly preferred are polymers having poly (meth) acrylate as a basic structure, and those having an acid anhydride structure in a main chain or a side chain thereof, and further, the acid anhydride structure is a carboxylic acid anhydride structure. Is preferred.

Preferred monomers for obtaining a polymer compound having such a preferred structure include monomers containing an acid anhydride structure and at least one group selected from acrylate and methacrylate groups.

Preferred examples of the monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group include compounds represented by the following general formula (1) or (2). be able to.

Embedded image (In the formula, R ^{1 to} R ⁶ are a hydrogen atom or a halogen atom or a monovalent organic group, which may be the same or different, preferably a hydrogen atom or a chain or cyclic group having 1 to 6 carbon atoms. Hydrocarbon groups, which may be the same or different, more preferably a hydrogen atom or a methyl group, which may be the same or different.)

[0022]

Embedded image (In the formula, R ⁷ represents a hydrogen atom or a methyl group,
n represents an integer of 1 to 5, preferably 1 or 2. )

An example of a monomer containing the acid anhydride structure represented by the above general formula (1) or (2) and at least one group selected from an acrylate group and a methacrylate group is acryl anhydride. Acid, methacrylic anhydride, angelic anhydride, tiglic anhydride, 4-methacryloxyethyl trimellitic anhydride, 4-methacryloxyethoxyethyl trimellitic anhydride and the like.

In the present invention, an acid anhydride structure and at least one selected from acrylate groups and methacrylate groups are used.
It may be a homopolymer of a monomer containing a kind group or a copolymer with a monomer containing no acrylate group and / or methacrylate group without containing an acid anhydride structure, and the latter is particularly desirable.

Examples of monomers not containing an acid anhydride structure and containing an acrylate group and / or a methacrylate group include some or all of the hydroxyl groups of a polyether polyol, a polycarbonate polyol, a polyester polyol, or a polyester carbonate polyol. A) Polyether (meth) acrylate, polycarbonate (meth) acrylate, polyester (meth) acrylate, or polyester carbonate (meth) acrylate converted to an acrylate ester. Here, the polyol means an alcohol having 2 or more hydroxyl groups, and the polyether polyol, the polycarbonate polyol, or the polyester polyol has a weight average molecular weight of 200 to 100,00.
0, preferably 250 to 20,000, more preferably 300 to 10,000. In addition, a weight average molecular weight is 500-100,000, or 1,000-2.
A polyol of 000 can sufficiently achieve the object of the present invention.

The above-mentioned polyether polyol can be obtained by polymerizing an alkylene oxide or adding an alkylene oxide to a polyhydric alcohol. Examples of the alkylene oxide include ethylene oxide, propylene oxide, oxetane, tetrahydrofuran and the like, and these may be used alone or in combination of two or more. As the polyhydric alcohol, the same glycols and polyols as described above can be used. Specific examples of polyether polyols, polyethylene glycol,
Examples thereof include polypropylene glycol and polybutylene glycol.

The above-mentioned polycarbonate polyol compound can be synthesized by polycondensation with a dihydric or higher polyhydric alcohol and a carbonic acid diester or phosgene. Polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,4
-Butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,3-bis (2
-Hydroxyethoxy) benzene, 1,4-bis (2-
(Hydroxyethoxy) benzene, neopentyl glycol, 2-methyl-1,8-octanediol, 1,9-
Nonanediol, 1,4-cyclohexanediol,
Diols such as 1,4-cyclohexanedimethanol,
Also, trimethylolpropane, trimethylolethane,
Pentaerythritol, ditrimethylolpropane, dipentaerythritol, glycerin, polyols such as sorbitol, and a hydroxyl group obtained by adding 1 to 5 equivalents of ethylene oxide, propylene oxide, or other alkylene oxide to the hydroxyl group of these polyols. Alcohols and the like. These polyhydric alcohols may be used alone or in combination of two or more.

As the carbonic acid diester, dimethyl carbonate,
Diethyl carbonate, diisopropyl carbonate, ethylene carbonate, propylene carbonate and the like,
These may be used alone or in combination of two or more.

The above polyester polyol can be synthesized by polycondensation of a hydroxycarboxylic acid or a lactone, or by polycondensation of a polyhydric alcohol and a polycarboxylic acid. Here, hydroxycarboxylic acid or lactone includes hydroxyacetic acid, lactic acid, β
-Propiolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, γ-caprolactone,
γ-heptalactone, γ-octalactone, γ-nonalactone, γ-decanolactone, δ-valerolactone, β
-Methyl-δ-valerolactone, δ-hexalactone,
δ-octalactone, δ-decanolactone, δ-nonalactone, ε-caprolactone and the like. In addition, in order to make a terminal functional group into a hydroxyl group, a polyhydroxy compound having 2 to 6 valences is usually added as a polymerization initiator, and polycondensation is performed.

When a polyester polyol is synthesized by polycondensation of a polyhydric alcohol and a polycarboxylic acid, the polyhydric alcohol may be ethylene glycol, 1,2-
Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8
-Octanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (2- Hydroxyethoxy) benzene, 1,4-cyclohexanediol, 1,
Glycols such as 4-cyclohexanedimethanol and the like, and polyols such as trimethylolpropane, trimethylolethane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, glycerin, sorbitol and the like can be mentioned.

Examples of the polycarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,
Examples thereof include 4-dicarboxylic acid, cis-tetrahydrophthalic acid, phthalic acid, isophthalic acid, and terephthalic acid. Further, a corresponding acid anhydride or dialkyl dicarboxylate may be used in place of the dicarboxylic acid.

The above-mentioned polyester carbonate polyol can be synthesized from the above-mentioned polyester polyol and diester carbonate or phosgene. When using a carbonic acid diester, dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate and the like can be exemplified, and these can be used alone or in combination of two or more. Is also good.

Method for Producing a Polymer Compound When a polymer compound comprising one or more monomers containing an acrylate group and / or a methacrylate group, which is preferably used in the present invention, is prepared, the polymer is preferably prepared by weight. The average molecular weight is preferably 10,000 or more. In particular, when a gel electrolyte is used, it is important to use a high molecular weight crosslinked polymer having low solubility in a solvent in the electrolytic solution. The production can be carried out under almost the same method and conditions as ordinary poly (meth) acrylate.

[0034] The polymerization method comprises the steps of: forming an acid anhydride structure and at least one selected from an acrylate group and a methacrylate group.
If necessary, the monomer containing the species group may be treated with an ultraviolet ray or a monomer which does not contain an acid anhydride structure and which contains an acrylate group and / or a methacrylate group and, if necessary, other copolymerizable monomers. Irradiation or heating is performed.

Examples of the other copolymerizable monomers include vinyl monomers and vinylidene monomers.
More specifically, vinyl esters, vinyl ethers,
(Meth) acrylates, allyl ethers and allyl esters are preferred. As specific examples, ethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, 2- (dimethylamino) ethyl (meth) acrylate, 2- (diethylamino) ethyl (meth) acrylate , 2- (di-n-
Propylamino) ethyl (meth) acrylate, 2-
(Di-propylamino) ethyl (meth) acrylate, 3- (dimethylamino) propyl (meth) acrylate, 1-piperidineethyl (meth) acrylate, 2
-N-morpholinoethyl (meth) acrylate, 2-
(Dimethylamino) ethoxyethyl (meth) acrylate, 2,2,6,6-tetramethylpiperidin-4-yl (meth) acrylate, 1-methyl-2,2,6,6
-Tetramethylpiperidin-4-yl (meth) acrylate polyethylene glycol (meth) acrylate, allyl alcohol, vinyl acetate, styrene, α-methylstyrene, vinyl chloride, vinylidene chloride, vinyl fluoride,
Examples include vinylidene fluoride, acrylonitrile, vinyl cyanoacetate, allylamine, isopropylacrylamide vinylene carbonate, and maleic anhydride.

In the case of polymerization by an ultraviolet irradiation method, a photosensitizer can be used. Examples of such a photosensitizer include benzophenone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone and the like. .
In the case of polymerization by a heating method, a thermal polymerization initiator can be used, and depending on the polymerization mode, peroxides such as benzoyl peroxide and peroxydicarbonate,
Azo compounds such as 2′-azobisisobutyronitrile,
Nucleophiles such as alkali metals and electrophiles such as Lewis acids can be used alone or in combination.

A copolymer containing an acid anhydride structure, a monomer containing at least one group selected from acrylate groups and methacrylate groups, and a monomer containing no acrylate group and / or methacrylate group without the acid anhydride structure In this case, the copolymerization ratio of both monomers is (monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group) / (excluding an acid anhydride structure, Or a monomer containing a methacrylate group) = 0.001 to 10, preferably 0.01 to 2.

When a solvent is used, examples thereof include alcohols such as methanol, ethanol, propanol, butanol and ethylene glycol; halogenated hydrocarbons such as dichloromethane, chloroform and dichloroethane; and aromatic hydrocarbons such as benzene, toluene and xylene. Hydrogens, saturated hydrocarbons such as hexane, heptane, decane and cyclohexane, ethers such as diethyl ether and tetrahydrofuran (THF), ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl Carbonates such as carbonate, ethyl acetate, propyl acetate, butyl acetate, γ-butyrolactone, δ-valerolactone, ε
Esters such as caprolactone. At this time, the weight ratio of the polymer compound and the non-aqueous solvent is (polymer compound) / (non-aqueous solvent) = 0.02 to 10, preferably 0.04 to 1.

After polymerization, the resulting polymer is in the form of a powder,
It is obtained in the form of a film, gel, etc., and can be used as a solid electrolyte. When the reaction proceeds in the presence of a solvent, a gel is usually formed, but the gel can be used as it is as a material for the polymer electrolyte,
Further, if necessary, the polymer can be used as a film-like or powder-like polymer from which the solvent has been removed by drying.

Polymer Solid Electrolyte The polymer solid electrolyte according to the present invention comprises the above-mentioned acid anhydride structure and one or more of monomers containing at least one group selected from acrylate and methacrylate groups. In the presence of one or more monomers containing no acrylate group and / or methacrylate group without the acid anhydride structure, or in the co-presence of other copolymerizable monomers, irradiation with ultraviolet light or radiation, or by heating In the produced polymer, a metal salt of Group Ia of the periodic table is blended.

Examples of the metal salt of Group Ia of the periodic table include lithium
Compounds such as sodium, potassium, etc.
The metal salt concentration in the electrolyte is 0.1 to 10 mol / l, preferably
Or a concentration of 0.5 to 2 mol / l in the solid electrolyte.
It is desirable that they are rare. Specific examples of metal salts include:
LiPF₆, LiBF_Four, LiClO_Four, LiAsF₆, Li _TwoSi
F₆, Li [(C_TwoF_Five)_ThreePF_Three] And other lithium salts
I can do it. In addition, a lithium salt represented by the following general formula is also used.
Can be used. LiOSO_TwoR⁸, LiN (SO_TwoR⁹)
(SO_TwoR^Ten), LiC (SO_TwoR¹¹) (SO_TwoR¹²) (SO
_TwoR¹³), LiN (SO_TwoOR¹⁴) (SO_TwoOR^Fifteen)(here,
R⁸~ R^FifteenMay be the same or different from each other
And a perfluoroalkyl group having 1 to 8 carbon atoms).
These lithium salts may be used alone or in combination with two or more.
You may mix and use the above.

Of these, LiPF ₆ , LiBF ₄ , Li
[(C ₂ F ₅ ) ₃ PF ₃ ], LiOSO ₂ R ⁸ , LiN (SO ₂ R
⁹ ) (SO ₂ R ¹⁰ ), LiC (SO ₂ R ¹¹ ) (SO ₂ R ¹² ) (SO ₂ R
¹³ ) and LiN (SO ₂ OR ¹⁴ ) (SO ₂ OR ¹⁵ ) are preferred, and more preferably LiPF ₆ .

The solid electrolyte is produced by preparing one or two of monomers containing an acid anhydride structure and at least one group selected from acrylate groups and methacrylate groups in advance.
At least one kind of a polymer prepared from at least one kind of a monomer not containing an acid anhydride structure and containing an acrylate group and / or a methacrylate group, and a metal salt of Group Ia of the periodic table; Alternatively, the polymerization can be carried out by, for example, a method of uniformly mixing the monomer and the metal salt of Group Ia of the Periodic Table during the polymerization and then proceeding with the polymerization. Particularly, the latter method is preferable because a solid electrolyte in which a metal salt is uniformly dispersed in a polymer can be easily obtained.

For example, an acid anhydride structure and at least one acrylate group and a methacrylate group may be selected in advance.
At least one kind of monomer containing at least one kind of group, at least one kind of monomer containing no acrylate group and / or methacrylate group containing no acid anhydride structure, and a metal of Group Ia of the periodic table. A salt and, if necessary, a solvent are added, and a uniform mixture thereof is applied on a flat substrate, and then, polymerization and gelation can be advanced by irradiating light, irradiating radiation, or heating. Thus, a solid electrolyte thin film having a thickness of 0.1 to 1000 μm can be obtained. In addition, when heating, it is desirable to perform in the temperature range which does not decompose | dissolve an electrolyte salt, for example, 0-100 degreeC, Preferably it is 20-90 degreeC.

The solid polymer electrolyte according to the present invention may contain a non-aqueous solvent such as a carbonate ester in addition to the above-mentioned polymer compound and a metal salt of Group Ia of the periodic table. . At this time, the weight ratio of the polymer compound and the non-aqueous solvent is preferably (polymer compound) / (non-aqueous solvent) = 0.02 to 10, more preferably 0.04 to 1. In order to include a non-aqueous solvent in the polymer compound, polymerization may be performed in the presence of a non-aqueous solvent when producing a polymer solid electrolyte, or a method of impregnating the non-aqueous solvent after polymerization. Etc. may be taken.

As the non-aqueous solvent, carbonate esters or lactones can be suitably used. Examples of carbonates include ethylene carbonate, propylene carbonate,
Dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, chain or cyclic carbonate such as dibutyl carbonate,
Examples of lactones include γ-butyrolactone, δ-
Valerolactone, ε-caprolactone and the like.

The solid polymer electrolyte according to the present invention has excellent liquid retention properties in a state containing a non-aqueous solvent, high ionic conductivity, and excellent storage stability in a charged state.
Such a polymer solid electrolyte can be used for, for example, primary batteries, secondary batteries, capacitors, electrochemical devices such as electrochromic display devices, and medical actuators. In particular, this polymer solid electrolyte is suitable for use as a substitute for an organic electrolyte for a lithium ion secondary battery. Further, it can be used as a binder used for dispersing and fixing the powdery electrode material on the current collector.

A secondary battery according to the present invention comprises a negative electrode containing a negative electrode active material,
It is composed of a positive electrode containing a positive electrode active material and the above-mentioned polymer solid electrolyte disposed therebetween.

By using the solid polymer electrolyte of the present invention, a secondary battery containing the solid polymer electrolyte has excellent battery performance such as charge / discharge characteristics and also has a good liquid retention property. Almost no liquid leakage, excellent storage stability in a charged state, and improved battery reliability.

As the negative electrode active material, metallic lithium, a lithium-containing alloy, a material capable of doping and undoping lithium ions, and the like can be used. Such a material capable of doping and undoping lithium ions can be appropriately selected from carbon materials, tin oxide, silicon, titanium oxide, transition metal nitrides, and the like. Among these, a carbon material capable of doping and undoping lithium ions is preferable, and it may be graphite or amorphous carbon. Specific examples include activated carbon, carbon fiber, carbon black, mesocarbon microbeads, and natural graphite.

As the positive electrode active material, MoS ₂ , TiS ₂ ,
Transition metal oxides or sulfides such as MnO ₂ and V ₂ O ₅ , LiCoO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , L
composite oxides composed of lithium and a transition metal such as iNiO ₂ and LiNi _X Co _(1-X) O ₂ , polyaniline, polythiophene, polypyrrole, polyacetylene, polyacene,
Examples include conductive polymer compounds such as dimercaptothiadiazole / polyaniline complex, and disulfide compounds. Among these, a composite oxide composed of lithium and a transition metal is particularly preferable.

When such a solid polymer electrolyte is used in a secondary battery, a battery can be manufactured by forming the solid polymer electrolyte into a film in advance and sandwiching it between a positive electrode and a negative electrode. Instead of a film, a polymer solid electrolyte formed in a gel in advance can be arranged. Further, in a battery manufacturing process including a step of forming a three-layer structure of a positive electrode, a separator, and a negative electrode and then impregnating the same with an electrolytic solution, a polymer compound, a metal of Group Ia of the periodic table is used instead of the electrolytic solution. It is also possible to adopt a method of adding and impregnating a solution comprising a salt and a non-aqueous solvent followed by gelation. In any case, by using the above-described solid polymer electrolyte according to the present invention, it is possible to manufacture a secondary battery while minimizing the modification of the conventional battery manufacturing process. The shape of the battery may be any shape such as a film type, a coin type, a cylindrical type, or a square type.

[0053]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Synthesis Example 1) Adipic acid 29 was placed in a glass reaction vessel equipped with a stirrer, thermometer and Liebig condenser.
2 g (2.0 mol), 318 g of diethylene glycol
(3.0 mol), and titanium tetrabutoxide 12 m
g, and gradually heated from 160 ° C. to 230 ° C.
The reaction was continued for 24 hours while removing generated water out of the reaction system. As a result, the desired polyester diol was obtained as a colorless oil in a yield of 538 g.

(Synthesis Example 2) The polyester diol obtained in Synthesis Example 3 (OH value: 208 mg KOH /
g) 53.8 g, acrylic acid 14.4 g, p-toluenesulfonic acid monohydrate 1.08 g, 4-methoxyphenol 0.11 g and toluene 100 ml were charged. 6
The resulting water was removed from the reaction system while heating and refluxing for an hour. After lowering the temperature to 50 ° C., 4.08 g of acetic anhydride was used.
Was further added and stirring was continued at this temperature for 2 hours. Next, at 50 ° C, it is a solid base product of Kyowa Chemical Industry Co., Ltd.
Add 20 g of Kyowaad 2000, and add 2 g at this temperature.
Stirring was continued for hours. Then, after cooling to room temperature, the insoluble matter was filtered, and the filtrate was concentrated under reduced pressure to obtain 61.5 g of the desired polyester acrylate as a colorless oil.

Example 1 <Preparation of Solution> Methacrylic anhydride was used as a monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group, and did not contain an acid anhydride structure. The acrylate of the polyester diol synthesized in Synthesis Example 2 was used as a monomer containing an acrylate group and / or a methacrylate group. As an electrolyte, ethylene carbonate and diethyl carbonate are used.
/ 7 mixture (volume ratio) with 1 (mol / l) of LiPF ₆
At a concentration of. Each is (monomer containing acid anhydride structure and at least one group selected from acrylate group and methacrylate group) / (monomer not containing acid anhydride structure and containing acrylate group and / or methacrylate group) / electrolysis After mixing at a liquid = 0.5 / 10/100 (weight ratio), 2,2′-azobis (2,4-dimethylvaleronitrile) was added to a concentration of 1000 ppm to prepare a solution.

<Preparation of Negative Electrode> Mesocarbon microbeads (trade name: MCMB6-28, d, manufactured by Osaka Gas Co., Ltd.)
002 = 0.337 nm, density 2.17 g / cm ³ ) 90 parts by weight of carbon powder and 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder were mixed, and N-
The paste was dispersed in methylpyrrolidone to prepare a paste-like negative electrode mixture slurry. Next, this negative electrode mixture slurry was applied to a negative electrode current collector made of a 20-μm-thick strip-shaped copper foil, and dried to obtain a strip-shaped carbon negative electrode. The thickness of the negative electrode mixture after drying is 2
It was 5 μm. Furthermore, this strip electrode is 15 mm in diameter.
, And compression molded to form a negative electrode.

<Preparation of Positive Electrode> L manufactured by Honjo Chemical Co., Ltd.
iCoO ₂ (product name: HLC-21, average particle size 8 μm)
91 parts by weight of fine particles, 6 parts by weight of graphite as a conductive material, and polyvinylidene fluoride (PVD) as a binder
F) was mixed with 3 parts by weight to prepare a positive electrode mixture, and dispersed in N-methylpyrrolidone to obtain a positive electrode mixture slurry. This slurry was applied to a 20-μm-thick aluminum foil positive electrode current collector, dried, and compression-molded to obtain a belt-shaped positive electrode. The thickness of the positive electrode mixture after drying was 40 μm.
Thereafter, the strip-shaped electrode was punched into a disk having a diameter of 15 mm to obtain a positive electrode.

<Preparation of Battery> Using the disc-shaped negative electrode and the disc-shaped positive electrode thus obtained, a stainless steel 2
A negative electrode, a polyethylene separator, and a positive electrode were stacked in this order in a 032 size battery can, and the solution 1 was impregnated. Then, a stainless steel plate (thickness 2.4) was placed in the battery can.
mm, diameter 15.4 mm), and the battery can (lid) was caulked via a polypropylene gasket. As a result, the airtightness in the battery can be maintained, and the diameter is 20 m.
m, a button-type secondary battery having a height of 3.2 mm was obtained. This battery was left in an oven at 50 ° C. for 6 hours to obtain a button-type gel-type polymer electrolyte secondary battery.

<Charge Storage Test> The gel-type polymer electrolyte secondary battery obtained in this manner was measured at 4.2 V and 1 m.
A Constant current constant voltage charging is performed, and the charging current is 50
The process was terminated when the current became less than μA. The gel-type polymer electrolyte secondary battery in a fully charged state was left at room temperature for 24 hours, and then decomposed to visually check whether or not liquefaction of the gel had occurred. Table 1 shows the results.

(Example 2) In Example 1, 4-methacryloxyethyl trimellitic anhydride was used as a monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group. Similarly, a gel type polymer electrolyte secondary battery was prepared, and a charge storage test was performed. The results are shown in Table 1.

(Example 3) In Example 1, 4-methacryloxyethoxyethyl trimellitic anhydride was used as a monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group. Similarly, a gel type polymer electrolyte secondary battery was prepared, and a charge storage test was performed. The results are shown in Table 1.

(Comparative Example 1) In the solution preparation of Example 1, (monomer containing acid anhydride structure and at least one group selected from acrylate group and methacrylate group) / (acid anhydride structure was not included) , An acrylate group and / or a methacrylate group-containing monomer) / electrolyte solution =
After adjusting the solution as 0/10/100 (weight ratio),
A gel-type polymer electrolyte battery was prepared, and a charge storage test was performed. Table 1 shows the results.

[0064]

[Table 1] ○: No liquefaction of the gel was observed visually ×: Liquefaction of the gel was observed visually

Example 4 <Measurement of Discharge Capacity> The discharge capacity of the gel-type polymer electrolyte secondary battery obtained in Example 1 was measured at room temperature. In this example, the current direction in which the negative electrode was doped with Li + was charged, and the current direction in which the negative electrode was undoped was discharge. The charging was performed by a 4.2 V, 1 mA constant current, constant voltage charging method, and was terminated when the charging current became 50 μA or less. Discharge was performed at a constant current of 1 mA up to 2.75 V. As a result of repeating the above charge and discharge for 10 cycles,
The charge and discharge efficiency at the 10th cycle was 97%, and the discharge capacity was 118 (mAh / g) based on the amount of the positive electrode active material.

[0066]

The polymer solid electrolyte according to the present invention has high ionic conductivity, excellent electrochemical stability, and high plasticizer and alkali metal salt retention performance. . The film-like material is flexible, and the gel-like material has excellent liquid retention.

Therefore, this polymer solid electrolyte can be suitably used for primary batteries, secondary batteries, capacitors, electrochemical devices such as electrochromic display devices, medical actuators, and the like.

In particular, a secondary battery containing this solid polymer electrolyte has excellent battery performance such as charge / discharge characteristics and good liquid retention, so that there is almost no fear of liquid leakage from the battery.
It has excellent storage stability in a charged state, and has improved battery reliability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 6/18 H01G 9/02 311 10/40 321 (72) Inventor Takeshi Ishitoku Takeshi Nakuura, Sodegaura City, Chiba Prefecture No. 580-32 Inside Mitsui Chemicals, Inc. (72) Inventor Kazuhisa Miyazaki Takumi Nagaura, Takumi, Chiba Prefecture No. 580-32 Inside Mitsui Chemicals Co., Ltd. (72) Inventor Hitoshi Onishi, Takumi Nagaura, Sodegaura-shi, Chiba No. 580 No. 32 Inside Mitsui Chemicals Co., Ltd. (72) Inventor Masahiro Toriida Chiura Prefecture Sodegaura-shi Nagaura character Taku No. 580 No. 32 Mitsui Chemicals Co., Ltd. (72) Inventor Nobu Enobu Sodegaura city Chiba Prefecture Nagaura character Takuji No. 580-32 Mitsui Chemicals Co., Ltd. (72) Inventor Shinobu Aoki 580-32 Nagaura Takuji, Nagaura, Sodegaura-shi, Chiba F-term in Mitsui Chemicals Co., Ltd. 4J100 AK31P AL08P AL65Q BA02P BA 07Q BA15P BA21Q BA22Q BC55P CA01 CA04 JA43 5G301 CD01 DA22 DD10 5H024 AA01 AA02 AA12 DD17 FF23 GG01 HH00 HH01 5H029 AJ06 AK03 AL01 AL02 AL06 AL12 AM02 AM03 AM04 AM05 AM07 AM16 DJ09 EJ12 HJ00 HJ01

Claims (15)

[Claims] 1. A polymer solid electrolyte comprising a polymer compound having an acid anhydride structure containing a metal salt of Group Ia of the periodic table. 2. The polymer compound having an acid anhydride structure is a polymer of a monomer containing an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group. The polymer solid electrolyte according to claim 1, wherein 3. The polymer solid electrolyte according to claim 1, wherein the acid anhydride structure is a carboxylic acid anhydride structure. 4. A method according to claim 1, wherein the monomer containing the acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group is a compound represented by the general formula (1). Item 4. The polymer solid electrolyte according to Item 3. Embedded image (In the formula, R ^{1 to} R ⁶ represent a hydrogen atom or a monovalent organic group.) 5. A method according to claim 1, wherein the monomer containing the acid anhydride structure and at least one group selected from acrylate and methacrylate groups is a compound represented by the general formula (2). Item 4. The polymer solid electrolyte according to Item 3. Embedded image (Wherein, R ⁷ represents a hydrogen atom or a methyl group, and n is 1
Represents an integer of from 5 to 5. ) 6. The polymer compound having an acid anhydride structure includes an acid anhydride structure, a monomer containing at least one group selected from acrylate groups and methacrylate groups, and an acid anhydride structure. Acrylate group and / or
The polymer solid electrolyte according to any one of claims 2 to 5, which is a copolymer with a monomer containing a methacrylate group. 7. A monomer which does not contain an acid anhydride structure and has an acrylate group and / or a methacrylate group is at least one selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and polyester carbonate polyols. 7. The solid polymer electrolyte according to claim 6, comprising an ester compound obtained by reacting a part or all of the hydroxyl groups of the polyol compound with acrylic acid or methacrylic acid. 8. The solid polymer electrolyte according to claim 7, wherein the polyol compound has a weight average molecular weight of 200 to 100,000. 9. A monomer comprising an acid anhydride structure and at least one group selected from an acrylate group and a methacrylate group, wherein the monomer does not contain an acid anhydride structure but contains an acrylate group and / or a methacrylate group. The polymer solid electrolyte according to any one of claims 6 to 8, wherein the weight ratio is 0.001 to 10. 10. The polymer solid electrolyte according to claim 1, wherein the metal salt of Group Ia of the periodic table is a lithium salt. 11. The metal salt of Group Ia of the periodic table, wherein the metal salt is Li
The polymer solid electrolyte according to claim 10, characterized in that a PF _6. 12. The polymer solid electrolyte according to claim 1, wherein said polymer compound is a gel-like material holding a non-aqueous solvent. 13. The weight ratio of the polymer compound to the non-aqueous solvent is (polymer compound) / (non-aqueous solvent) = 0.
The polymer solid electrolyte according to claim 12, wherein the number is from 02 to 10. 14. A secondary battery comprising the polymer solid electrolyte according to claim 1. 15. A polymer solid electrolyte according to claim 1, metal lithium, a lithium-containing alloy, a carbon material capable of doping and undoping lithium ions, and lithium ion doping as a negative electrode active material. Negative electrode and positive electrode active material containing at least one selected from the group consisting of tin oxide capable of undoping, silicon capable of doping and undoping lithium ions, and titanium oxide capable of doping and undoping lithium ions A secondary battery comprising a positive electrode containing a composite oxide of lithium and a transition metal.