JP3045852B2 - Manufacturing method of solid electrolyte secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a solid electrolyte secondary battery, and more particularly to a novel method for producing a solid secondary battery having excellent productivity and a long charge / discharge cycle life.

[0002]

2. Description of the Related Art In recent years, with the development of electronic equipment, there has been a demand for the development of a secondary battery which is small, lightweight, has a high energy density and can be repeatedly charged and discharged. As a secondary battery of this type, lithium or a lithium alloy is used as a negative electrode active material, molybdenum, vanadium, titanium, oxides such as niobium, sulfide, selenide, and the like are used as a positive electrode active material, and propylene carbonate is used as an electrolyte. Those using a non-aqueous liquid electrolyte such as dioxolan or dimethoxyethane are known. However, since these electrolyte liquids have low viscosity, they easily leak from the sealing portion during storage or use of the battery, and thus have a problem in long-term reliability.

[0003] To solve this problem, various solid electrolytes have been proposed. Above all, solid polymer electrolytes based on ion-conductive polymer materials and composited with alkali metal salts can easily process uniform thin films into arbitrary shapes. , And a lithium battery using the same have been proposed.

However, the above-mentioned solid polymer electrolyte battery is
Since the interface resistance between the solid polymer membrane and the electrode is large, there is a disadvantage that the charge / discharge current density is small. this is,
This is because the contact between the solid polymer membrane and the electrode is a contact between the solids, and the adhesion is insufficient.

In order to solve this problem, a method of uniformly dissolving a solid polymer electrolyte in a solvent, applying the solution to an electrode, and evaporating and removing the solvent to form a solid polymer membrane; a photo-curing type or a thermosetting type A method has been proposed in which a liquid electrolyte containing an organic polymer and an inorganic ionic salt is applied to an electrode and then cured to form a solid polymer diaphragm.

However, in the battery using the solid polymer membrane, a liquid polymer electrolyte is applied to an electrode, and then the solvent is removed by evaporation or heating, and light irradiation is performed, as compared with a battery using a conventional liquid electrolyte. The step of cross-linking and hardening is indispensable due to, for example, low productivity. In addition, since the solid polymer electrolyte has low mechanical strength, when used in a cylindrical battery, when the electrode and the solid polymer membrane are wound, the solid polymer membrane breaks or extends, resulting in short-circuiting and dimensional problems. Has the drawback of causing a change or protrusion.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a method for manufacturing a solid electrolyte secondary battery which is excellent in productivity and has a long charge / discharge cycle life. The purpose is to provide.

[0008]

Means for Solving the Problems In a solid electrolyte secondary battery, the present inventors mix liquid A and liquid B in which at least one of the following liquids A and B contains an alkali metal salt. The inventor has found that the above object can be achieved by injecting the resulting product in a liquid state into the battery, curing the product, and then using it as a solid electrolyte, thereby completing the present invention.

That is, a method for manufacturing a solid electrolyte secondary battery of the present invention comprises a negative electrode made of lithium or a lithium alloy, a positive electrode made of a metal chalcogen compound or a composite compound of lithium and a metal chalcogen compound, and a solid electrolyte. In the method for producing a solid electrolyte secondary battery, as the solid electrolyte, at least one of the following solution A and solution B contains an alkali metal salt, and a product obtained by mixing solution A and solution B is used. It is characterized by being injected into a battery in a liquid state and cured.

Solution A is a solution in which a radical polymerization initiation accelerator is dissolved in a substituted or unsubstituted alkoxypolyethylene glycol ester of acrylic acid represented by the general formula (1):

[0011]

Embedded image

Wherein R ¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 2 ≦ m ≦ 30. The liquid is a polyalkylene glycol dialkyl ether represented by the general formula (2)

[0013]

Embedded image

(Wherein R ³ and R ⁵ may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms, and R ⁴ is hydrogen or an alkyl group having 1 to 3 carbon atoms. And n represents an integer of 2 ≦ n ≦ 30); and / or an organic non-aqueous solvent represented by the general formula (3)

[0015]

Embedded image

(Where X is

[0017]

Embedded image

Wherein R ⁶ represents a monovalent hydrocarbon group having 1 to ⁶ carbon atoms, R ⁷ and R ⁸ may be the same or different, and represent a single bond or 1 to 6 carbon atoms.
6 represents a divalent hydrocarbon group, R ⁹ represents a monovalent hydrocarbon group having 1 to 6 carbon atoms or a cyano group, and R ⁶ and R ⁹ may be mutually connected to form a ring. , P, q and r each represent 0 or 1, and when R ⁹ is a monovalent hydrocarbon group, p + q + r> 0) is a solution in which the radical polymerization initiator is dissolved.

The solid electrolyte used in the present invention comprises a solution A in which a radical polymerization initiator is dissolved in a compound represented by the general formula (1) and a compound represented by the general formula (2) and / or Alternatively, it is a product obtained by mixing with a solution B in which a radical polymerization initiator is dissolved in a compound represented by the general formula (3), followed by curing. Further, at least one of the solution A and the solution B contains an alkali metal salt.

Further, at least one of the solution A and the solution B may contain a radical polymerization retarder, if desired.

The general formula (1) used in the present invention
Is a monoalkoxy polyethylene glycol ester of acrylic acid or alkyl-substituted acrylic acid, as shown by its structural formula, that is, a polyether-based macromonomer containing an oxyethylene unit in the molecule, and is liquid at room temperature. It shows.

In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 5, preferably 1 to 3 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl,
Examples thereof include isopropyl, butyl, and pentyl, and preferably a hydrogen atom and an alkyl group of methyl and ethyl. R ² is an alkyl group having 1 to 5, preferably 1 to 3 carbon atoms, and includes methyl, ethyl, propyl, isopropyl, butyl, pentyl and the like.
Methyl, ethyl, propyl and the like. The number of oxyethylene units in the compound represented by the general formula (1), that is, the value of m is 2 ≦ m ≦ 30, preferably 2 ≦ m ≦ 20, and more preferably 3 ≦ m ≦ 15. .

Specific examples of the monoalkoxypolyethylene glycol ester of acrylic acid or alkyl-substituted acrylic acid represented by the general formula (1) include methoxypolyethylene glycol methacrylate and ethoxypolyethylene glycol methacrylate having an oxyethylene unit number within the above range. Methoxy polyethylene glycol acrylate, ethoxy polyethylene glycol acrylate and the like. These may be used alone or in combination of two or more.

The radical polymerization initiator used in the present invention is not particularly limited as long as it is soluble in the compound of the formula (1) and has an action of reducing the radical polymerization initiator described below. Instead, various anilines, amines, reductive transition metal compounds, sulfur-containing compounds and the like are exemplified.

Specifically, for example, aniline, N, N-
Dimethylaniline, N, N-diethylaniline, N, N
Anilines such as dibutylaniline; amines such as triethylamine, diethylamine, piperidine, 1,2-diaminoethane; FeCl ₂ .nH ₂ O, FeS;
Fe (II) salts such as FeSO ₄ ; CoCl ₂ , CoBr
₂ , Co (II) salts such as CoSO ₄ and CoS; MoCl
Mo (V) salts such as ₅ ; methanethiol, ethanethiol, benzenethiol, phenylmethanethiol, 1,
Thiols such as 4-butanedithiol and p-mercaptobenzoic acid; Thiol salts such as potassium ethanethiolate and sodium ethanethiolate; diethylsulfide, ethylthiobenzene, 1,2-bis (methylthio)
Ethane, 4,4'-thiodibenzoic acid, 3- (methylthio) propanol, bis (ethylthiomethyl) sulfide, thiacyclooctane, 1,2-dithiane, 2,3-
Sulfides such as dihydro-1,4-dithianaphthalene; or various sulfites; sulfinic acid and the like; aniline, N, N-dimethylaniline, N, N-diethylaniline, triethylamine, FeSO ₄ , Fe
Cl ₂ .nH ₂ O, ethanethiol, benzenethiol, sodium ethanethiolate, diethyl sulfide and the like are preferable. These may be used alone or in combination of two or more.

Solution A is one in which these radical polymerization initiation accelerators are dissolved in the compound of the general formula (1). The concentration of the radical polymerization initiation accelerator in Solution A is 0.00
01 to 10% by weight is preferred, and 0.0005 to 5% by weight
Is more preferred.

It should be noted that, in solution A, two to two
It is preferable to blend a linear or branched compound having four alkyl-substituted or unsubstituted acryloyl groups. The compounding amount of the compound 1 represented by the general formula (1)
The amount is usually 50 parts by weight or less, preferably 1 to 50 parts by weight, more preferably 2 to 30 parts by weight with respect to 00 parts by weight.

Examples of such a compound having an alkyl-substituted or unsubstituted acryloyl group include a compound represented by the general formula (4) having two alkyl-substituted or unsubstituted acryloyl groups at both ends. Diester of linear polyethylene glycol

[0029]

Embedded image

(Wherein R ¹⁰ and R ¹¹ may be the same or different and each represents a hydrogen atom or a carbon atom
Represents an alkyl group of -5, preferably 1-3.
To 30, preferably 5 to 20), and particularly, a compound having an acryl group or a methacryl group at both ends is exemplified as a suitable substance.

As the compound having an alkyl- or unsubstituted acryloyl group at three or four terminals, a compound represented by the general formula (5) is preferable, and a compound having an acryl or methacryl group at the terminal is particularly preferable. . Specific examples include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetramethacrylate, and pentaerythritol tetraacrylate.

[0032]

Embedded image

(Wherein, R ¹² represents an alkyl group having 1 to 5 carbon atoms, a represents 0 or 1, and R ¹³ represents hydrogen or an alkyl group having 1 to 5 carbon atoms.)

The compound represented by the general formula (2) used in the present invention is a polyether oligomer in which both ends are alkyl etherified, as known from its structural formula, and which is a liquid at room temperature. It is.

R ⁴ in the formula is a hydrogen atom or a carbon atom having 1 to
3 represents an alkyl group, and examples of the oxyalkylene unit include an oxyethylene unit, an oxypropylene unit, and an oxybutylene unit, and two or more oxyalkylene units may coexist. The number n of these oxyalkylene units is 2 ≦ n ≦ 30, preferably 2 ≦ n ≦ 20, and more preferably 3 ≦ n ≦ 15. R ³ and R ⁵ in the formula may be the same or different, and each represents an alkyl group having 1 to 5, preferably 1 to 3 carbon atoms, such as methyl, ethyl and propyl. , Isopropyl and the like.

Specific examples of such polyalkylene glycol dialkyl ethers include dimethoxy polyethylene glycol, diethoxy polyethylene glycol, dipropoxy polyethylene glycol, dimethoxy polypropylene glycol, diethoxy polypropylene glycol, dimethoxy polyethylene propylene glycol, and dimethoxy polyethylene glycol. Butylene glycol is exemplified. These may be used alone or in combination of two or more.

The compound represented by the general formula (3) is an organic non-aqueous solvent which is liquid at room temperature.

R ⁶ in the formula has 1 to 6 carbon atoms, preferably 1 to 6 carbon atoms.
To 4 hydrocarbon groups, examples of which include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, and pentyl; and aryl groups such as phenyl. R ⁷ and R ⁸ may be the same or different and each is a single bond or a divalent hydrocarbon group having 1 to 6 carbon atoms,
Examples thereof include an alkylene group such as methylene, ethylene, trimethylene, and propylene; and an arylene group such as phenylene.

R ⁹ is a cyano group or a monovalent hydrocarbon group having 1 to 6, preferably 1 to 3 carbon atoms. Examples of the hydrocarbon group are the same as those of R ⁶ . Further, R ⁶ and R ⁹ may be mutually connected to form a ring, and in this case, R ⁶ and R ⁹ each constitute a part of a divalent hydrocarbon group. Such a divalent hydrocarbon group usually has 2 to 6 carbon atoms, and examples thereof include an alkylene group such as ethylene, trimethylene, propylene, and tetramethylene. p, q and r are each 0 or 1
And when R ⁴ is a monovalent hydrocarbon group, p + q
+ R> 0.

X represents the following divalent group.

[0041]

Embedded image

Examples of the organic non-aqueous solvent represented by the general formula (3) include ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethoxyethane, acetonitrile, dimethyl sulfoxide, dioxolan, sulfolane and the like. These may be used alone or in combination of two or more. This organic non-aqueous solvent can be used regardless of the value of its dielectric constant, but particularly preferably has a dielectric constant of 30 or more.

The radical polymerization initiator used in the present invention is soluble in the compound represented by the general formula (2) and / or the compound represented by the general formula (3), and easily generates a radical. If so, there is no particular limitation. Organic peroxides and the like are exemplified as suitable substances. As the organic peroxide, dialkyl peroxide, diacyl peroxide, peroxyester, hydroperoxide, ketone peroxide and the like are used,
Specifically, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide,
Dicumyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, tert-butyl peroxyacetate, tert-
Butyl peroxyisobutyrate, tert-butyl peroxypivalate, acetyl peroxide, diisopropyl peroxycarbonate, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide,
And propionyl peroxide. Benzoyl peroxide, tert-butyl peroxyisobutyrate, acetyl peroxide, methyl ethyl ketone peroxide and the like are preferred. These may be used alone or in combination of two or more.

Solution B is a solution in which the above-mentioned radical polymerization initiator is dissolved in the compound of the general formula (2) and / or the compound of the general formula (3). The concentration of the radical polymerization initiator in the solution B is preferably 0.0001 to 10% by weight, more preferably 0.0005 to 5% by weight.

When the compound of the general formula (2) and the compound of the general formula (3) are used in combination, the use ratio of both is not particularly limited, but usually, the compound of the general formula (2) and the compound of the general formula (3) ) Is preferably in the range of 99: 1 to 1:99, more preferably in the range of 90:10 to 10:90.

In the present invention, the above-mentioned solution A and / or
Alternatively, the solution B contains an alkali metal salt. Further, a radical polymerization retarder may be optionally additionally contained.

The alkali metal salt is not particularly limited as long as it is soluble in the compound of the general formula (1), the compound of the general formula (2) or the compound of the general formula (3). Examples of the alkali metal salt include alkali metal salts of perchlorate such as lithium perchlorate, sodium perchlorate and potassium perchlorate; tetrafluorocarbons such as lithium tetrafluoroborate, sodium tetrafluoroborate and potassium tetrafluoroborate Alkali metal salts of boric acid; alkali metal salts of hexafluorophosphoric acid such as lithium hexafluorophosphate and potassium hexafluorophosphate; alkali metal salts of trifluoroacetic acid such as lithium trifluoroacetate; lithium trifluoromethanesulfonate and the like Examples include alkali metal salts of trifluoromethanesulfonic acid That. These may be used alone or in combination of two or more.

The content of the alkali metal salt is preferably from 1 to 30 parts by weight, more preferably from 3 to 20 parts by weight, based on 100 parts by weight of the total of the solution A and the solution B.

The radical polymerization retarder is not particularly limited as long as it has an action of inhibiting or suppressing a radical polymerization reaction. Preferred examples include 1,1-diphenyl-2-picrylhydrazine (DPPH),
3,5-triphenylferdazyl (VDZ), 2,6
-Di-tert-butyl-α- (3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1-ylidene-p-tolyloxyl (Galvinoxyl), 2,2,
Organic oxygen radicals such as 6,6-tetramethyl-4-piperidone-1-oxyl, N- (3-N-oxyanilino-1,3-dimethylbutylidene) -aniline oxide, tri (p-nitrophenyl) methyl or Stable organic radicals such as organic nitrogen radicals; high valent metal salts such as ferric chloride, ferric bromide, and cupric chloride; quinones such as dichloroquinone and hydroquinone; organic sulfur compounds such as dithiobenzoyl disulfide Is exemplified, DP
Stable radicals such as PH are particularly preferred. In the present invention, stability in stable radicals generally means 0 to
It means that it is stable at 50 ° C, preferably in the range of 5 to 40 ° C.

The amount of the radical polymerization retarder to be added is such that the ratio of the radical polymerization retarder / radical polymerization initiator (molar ratio) is usually 2 or less, preferably 0.001 to 1.5, and particularly preferably 0 to 1.5. 0.01 to 1.0.
Of course, two or more radical polymerization retarders can be used in combination.

The solid polymer electrolyte used in the present invention is cured by mixing the liquid A and the liquid B. At this time, the mixing ratio of the liquid A and the liquid B is not particularly limited as long as the object of the invention is not impaired, but usually, the weight ratio of the liquid A to the liquid B is 1:99 to 90:10, and 5: 95-85:
More preferably, it is within the range of 15. If the amount of the liquid A is excessive, the ionic conductivity of the produced solid polymer electrolyte at low temperature is apt to decrease. If the amount of the liquid B is excessive, the strength of the produced solid polymer film becomes poor. easy.

The temperature at which the liquid A and the liquid B are mixed is usually in the range of 0 to 50 ° C., preferably in the range of 5 to 40 ° C. In addition, it is preferable that the handling operation of these two liquids is performed in a dry atmosphere.

When a radical polymerization retarder is used, A
After the induction period for a while after mixing the liquid and the liquid B, the curing starts, and no other special treatment is required. The temperature at the time of curing is usually in the range of 0 to 50 ° C., preferably 5 to 40 ° C., and the curing time is appropriately determined by various conditions such as the charged amount of each component and the temperature. From the viewpoint of the properties, usually, 1 minute to 24 hours are preferable, and 5 minutes to 12 hours are more preferable.

Incidentally, an organic non-hydrophilic solvent such as ethylene carbonate, propylene carbonate, dimethoxyethane or dimethyl sulfoxide may be coexisted in the solution A as long as the object of the present invention is not impaired. The coexistence amount at this time is usually 98% by weight or less of the total amount, preferably 1 to 95% by weight, more preferably 5 to 92% by weight.

As described above, the solid electrolyte used in the present invention can be obtained by a curing reaction only at the ordinary temperature by mixing the solution A and the solution B. The rate of the curing reaction can be freely controlled by selecting the type and concentration of the radical polymerization initiator, the radical polymerization initiation accelerator and the monomer. Thereby, the period during which the mixture can be handled as a liquid can be adjusted. Further, by using the radical polymerization retarder, it is possible to set an induction period from the time when the liquid A and the liquid B are mixed to the time when the curing starts, so that a wider range of operation time can be set.

That is, the solid electrolyte used in the present invention is:
During the induction period after the liquid A and the liquid B are mixed and the curing starts, the liquid electrolyte can be handled in the same manner as the liquid electrolyte.

Therefore, by using this solid electrolyte, during the assembly of the battery, after the liquid A and the liquid B are mixed, the liquid can be used as a liquid during an operation period including an induction period until curing starts. Perform the same injection as for the electrolyte, electrodes,
In addition, a solid electrolyte secondary battery can be manufactured by impregnating or holding the separator separating the positive electrode and the negative electrode and curing the electrolyte in the battery after assembling the battery.

As the liquid injection method used in the present invention, the solid electrolyte used in the present invention can be handled in the same manner as the liquid electrolyte during the induction period, and any liquid injection method used for injecting the liquid electrolyte may be used. There is no particular limitation. A preferable method is, for example, injection under reduced pressure.

The positive electrode active material used in the present invention includes:
A metal chalcogen compound or a composite compound of lithium and a metal chalcogen compound is used. Examples of the metal chalcogen compound include, for example, oxides, sulfides, and selenides of metals such as titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), and niobium (Nb). Include MnO ₂ , V ₂ O ₅ , Cr ₃ O
₈ , oxides such as V ₆ O ₁₃ ; sulfides such as TiS ₂ and V ₂ S ₂ ; selenides such as VSe ₂ and NbSe ₃ . Examples of a composite compound of lithium and a metal chalcogen compound include, for example, LiCoO ₂ , LiMn
₂ O _{4 and the} like are exemplified. Each of these may be used alone, or two or more of them may be appropriately selected and used. Further, the above compound may be crystalline or amorphous.

The positive electrode used in the present invention comprises a binder such as polytetrafluoroethylene, polyethylene, or ethylene-propylene copolymer, and a conductive material such as carbon black or acetylene black, if necessary. It is prepared by mixing or forming the agents and then forming them into sheets. Here, a solid polymer electrolyte such as a mixture of polyethylene glycol and an alkali metal salt may be used as the binder. Further, the solid electrolyte and the binder may be used in combination.

The negative electrode active material used in the present invention is preferably lithium or a lithium alloy. As the lithium alloy, Li-Al alloy, Li-In alloy, Li-Al
-Mn alloy and the like are exemplified.

The negative electrode used in the present invention is prepared by processing the above-mentioned lithium or lithium alloy into a foil or a pellet.

Examples of the separator used in the present invention include a porous membrane made of polypropylene; a nonwoven fabric such as polyethylene and polypropylene; and a net made of polypropylene. The solid electrolyte used in the present invention can be separated from the positive electrode and the negative electrode. Is not particularly limited as long as it can be impregnated or retained.

[0064]

As described above, the present invention provides a method for manufacturing a solid electrolyte secondary battery having excellent productivity.

Further, in the method for producing a solid electrolyte battery of the present invention, a liquid polymer electrolyte is applied to an electrode in order to inject the solid electrolyte in a liquid state and cure in the battery, and the remaining solvent is removed by evaporation, or A step of crosslinking and curing by heating, light irradiation, or the like is unnecessary.

On the other hand, the solid electrolyte used in the present invention is:
After the mixing, the composition is cured at room temperature, so that operations such as heating and light irradiation that adversely affect the electrode performance are not required, which is very effective in maintaining the electrode performance.

Furthermore, since it is possible to form a film simultaneously and directly on both the positive electrode and the negative electrode, the adhesion between the film and the electrode is very good, and the film has flexibility and mechanical strength. Is excellent. Since sufficient strength is obtained by impregnating the solid electrolyte with the separator, there is no short circuit due to breakage of the solid electrolyte.

Further, even if the charge / discharge cycle is repeated, dendrites of lithium are not formed on the electrode due to the characteristics of the solid electrolyte used in the present invention. Therefore, an excellent solid electrolyte secondary battery having a long charge / discharge cycle life can be obtained.

[0069]

The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited by these descriptions.

Example FIG. 1 is a longitudinal sectional view of a cylindrical solid electrolyte secondary battery in the production method of the present invention. Negative electrode 5 made of metallic lithium
And a separator 6 made of a polypropylene nonwoven fabric, and a positive electrode 7 in which spinel-type LiMn ₂ O ₄ is coated on a stainless steel substrate having a thickness of 10 μm.
Was wound in a spiral shape and stored on the insulator 2 in a bottomed cylindrical container also serving as a negative electrode terminal.

As the liquid A, methoxypolyethylene glycol monomethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
M90G, number of oxyethylene units: 9)
A solution obtained by adding 10 mg of N, N-dimethylaniline; as a solution B, 10 ml of propylene carbonate, 0.75 g of lithium perchlorate and 0.05 of benzoyl peroxide
g, and 3 mg of 1,1-diphenyl-2-picrylhydrazyl (DPPH) was further added. The solutions A and B2 were mixed at 25 ° C. at a weight ratio of 1: 9. This mixed solution was injected under reduced pressure into a cylindrical container containing a power generating element to assemble a cylindrical solid electrolyte secondary battery. When the battery was disassembled 6 hours after assembling, the mixed solution injected into the battery was cured, and 6 in FIG.
It was a layer composed of a separator and a solid electrolyte.

Further, 8 insulating plates, 9 insulating sealing plates, 1
By providing a positive electrode terminal of 0 and a positive electrode lead wire of 11, a cylindrical solid electrolyte secondary battery was completed.

Comparative Example A cylindrical non-aqueous solvent secondary battery was assembled in the same manner as in Example except that propylene carbonate containing 0.7 mol / L of lithium perchlorate was used instead of the solid electrolyte.

The charge / discharge cycle in the voltage range from 3.4 V to 2.0 V was carried out on the cylindrical secondary batteries of Examples and Comparative Examples thus produced at a room temperature of 20 ° C. and a constant current of 100 mA. Was. The result is shown in FIG. FIG.
In the graph, A is the battery of Example, and B is the discharge capacity retention rate curve of the battery of Comparative Example.

As is clear from FIG. 2, the cylindrical solid electrolyte secondary battery of the embodiment according to the present invention has a small deterioration in the discharge capacity retention rate with an increase in the number of cycles and has excellent charge / discharge reversibility. ing. On the other hand, in the battery of the comparative example, dendrite was generated, and the capacity retention rate was sharply reduced after 100 cycles.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a solid electrolyte secondary battery of an example.

FIG. 2 is a characteristic diagram showing a change in a discharge capacity retention ratio with respect to the number of charge / discharge cycles in cylindrical secondary batteries of an example and a comparative example.

[Description of Signs] 1 Solid electrolyte secondary battery 2 Insulator 3 Stainless steel container 4 Electrode group 5 Negative electrode 6 Separator + Solid electrolyte 7 Positive electrode 8 Insulating plate 9 Insulating sealing plate 10 Positive electrode terminal 11 Positive electrode lead A Discharge capacity of battery of embodiment Retention rate curve B Discharge capacity retention rate curve of battery of comparative example

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masanobu Suga 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Japan Japan Petroleum Corporation Central Research Laboratory (72) Inventor Seiichi Akita 8 Chidori-cho, Naka-ku, Yokohama, Kanagawa Japan Petroleum Co., Ltd. Central Research Laboratory (72) Inventor Nobuyuki Kuroda 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Japan Japan Petroleum Co., Ltd. Central Research Laboratory (56) References JP-A-4-211412 (JP, A) JP-A-4-331220 (JP, A) JP-A-5-114419 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 10/40

Claims (1)

(57) [Claims] 1. A method for producing a solid electrolyte secondary battery comprising: a negative electrode made of lithium or a lithium alloy; a positive electrode made of a metal chalcogen compound or a composite compound of lithium and a metal chalcogen compound; and a solid electrolyte. As a solid electrolyte, at least one of the following liquid A and liquid B contains an alkali metal salt, a product obtained by mixing the liquid A and the liquid B at a temperature of 40 ° C. or lower,
A method for producing a solid electrolyte secondary battery, comprising: injecting a liquid during battery assembly, impregnating or holding a separator for separating a positive electrode and a negative electrode, and then curing at a temperature of 40 ° C. or lower. Solution A is a solution in which a radical polymerization initiation accelerator is dissolved in a substituted or unsubstituted alkoxypolyethylene glycol ester of acrylic acid represented by the general formula (1). (Wherein, R ¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms,
Represents an integer of 2 ≦ m ≦ 30) Solution B is a polyalkylene glycol dialkyl ether represented by the general formula (2). (Wherein, R ³ and R ⁵ may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms, and R ⁴ represents hydrogen or an alkyl group having 1 to 3 carbon atoms. , N represents an integer of 2 ≦ n ≦ 30); and / or an organic non-aqueous solvent represented by the general formula (3): (Wherein X is R ⁶ represents a monovalent hydrocarbon group having 1 to ⁶ carbon atoms, and R ⁷ and R ⁸ may be the same or different, and represent a single bond or a divalent hydrocarbon group having 1 to 6 carbon atoms. R ⁹ represents a monovalent hydrocarbon group having 1 to 6 carbon atoms or a cyano group; R ⁶ and R ⁹ may be linked to each other to form a ring; , Q and r each independently represent 0 or 1, and when R ⁹ is a monovalent hydrocarbon group, q + p + r> 0) is the solution in which the radical polymerization initiator is dissolved.