JP2003217665A - Method of manufacturing solid electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a whole solid type solid electrolyte battery with an excellent performance, capable of reducing the interface resistance between active material particles and the solid electrolyte. <P>SOLUTION: A modifier comprising the material expressed in the following formula is included in a solid electrolyte or solid electrolyte precurser by at least 0.01 wt.% and less than 10 wt.%, and the battery is completed through the modification process including the initial charge, etc. The whole quantity of the modifier is consumed in the modification process. The battery is applied to a polymer solid electrolyte lithium battery, for example. The formula 1: O=C (OR) (OR'). In the formula, R and R' express hydrocarbon, and both may be either the same or different from each other, or may be formed in a ring by bonding to each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolyte battery and a method for manufacturing the same, and more particularly to a solid electrolyte battery having reduced interface resistance between an electrode and a solid electrolyte.

[0002]

2. Description of the Related Art A lithium battery uses a non-aqueous electrolytic solution, which may cause leakage. On the other hand, the gel electrolyte battery in which the non-aqueous electrolyte solution is held in the polymer material also has a risk of leakage.

On the other hand, a battery using a solid electrolyte has been studied as a battery which has no risk of liquid leakage.

The solid electrolyte battery will be described in more detail by taking a polymer solid electrolyte battery as an example. When the electrode active material of the polymer solid electrolyte battery is in powder form, a general method for producing the electrode (positive electrode or negative electrode) is as follows. If necessary, a binder or a conductive agent is added to the active material powder, and a paste is formed using a solvent. After coating the current collector, the solvent is volatilized to form the active material powder into a plate shape. Alternatively, a binder or a conductive agent is added to the active material powder as needed, and the active material powder is molded into a pellet type plate by a press die or the like.
Impregnating the voids between the particles of the active material powder molded into the plate-like solid electrolyte precursor containing an ion dissociative alkali metal salt in a liquid monomer having a reactive functional group at the terminal,
The functional group of the monomer is reacted by irradiating with heat, light, electron beam or the like or by a chemical reaction, whereby the solid electrolyte precursor becomes a solid electrolyte. In this way, a composite electrode in which the solid electrolyte and the active material are composited is formed.

Alternatively, if necessary, a binder or a conductive agent is added to the active material powder, a polymer containing an ion-dissociating alkali metal salt is mixed, and the temperature is raised to 60 ° C. or higher, if necessary. The active material powder is molded into a pellet type plate by a press die or the like. In this way, a composite electrode in which the solid electrolyte and the active material are composited is formed.

Examples of the above powdery active material include metal oxide powder and lithium transition metal composite oxide powder for the positive electrode, and carbonaceous material powder and lithium alloy powder for the negative electrode. .

However, the solid electrolyte battery has a problem in that it has a higher internal resistance than a battery using a non-aqueous electrolyte and cannot be a battery having sufficient performance.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solid electrolyte battery having reduced internal resistance and excellent performance.

[0009]

The present invention is a method for producing a solid electrolyte battery comprising a positive electrode, a negative electrode and a solid electrolyte, wherein a modifier comprising a substance represented by (Formula 1) is used as the solid electrolyte or the solid electrolyte. It is a method for producing a solid electrolyte battery, characterized in that it is contained in an electrolyte precursor and a battery is completed through a reforming process.

O = C (OR) (OR ′) (Formula 1) (wherein R and R ′ are hydrocarbons, which may be the same or different, or are bonded to each other. It may form a ring.)

Further, the modifier is contained in an amount of 0.01% by weight or more and less than 10% by weight with respect to the solid electrolyte or the solid electrolyte precursor.

Further, the solid electrolyte battery is characterized in that it does not contain a substance represented by (Formula 1).

Further, the solid electrolyte battery is characterized by comprising a positive electrode capable of transmitting / receiving lithium ions and a negative electrode capable of transmitting / receiving lithium ions.

Further, the solid electrolyte battery is characterized by including a negative electrode using a carbonaceous material.

Further, the solid electrolyte is a polymer solid electrolyte.

A solid electrolyte battery manufactured by the above-described method for manufacturing a solid electrolyte battery.

The present inventors initially thought that the reason for the high internal resistance of a battery using a solid electrolyte was that the solid electrolyte had a low ionic conductivity. Alternatively, it was considered that the contact between the active material and the solid electrolyte was between solids. Alternatively, it was considered that the solid electrolyte had a low affinity for the surface of the active material. However, as we proceeded with the investigation, it became clear that there were factors that could not be attributed to any of these causes.

That is, a direct reaction between the active material and the solid electrolyte occurs, and the resulting reaction product is present at the contact interface between the active material particles and the solid electrolyte, which is a cause of high internal resistance. It was considered.

In the present invention, a modifying agent is contained in a solid electrolyte or a solid electrolyte precursor, and the modifying agent is allowed to act on the active material in a modifying step, thereby forming a coating having low resistance on the surface of the active material particle. Let it form. This makes it possible to avoid the above-mentioned direct reaction between the active material and the solid electrolyte, so that the interface resistance between the active material particles and the solid electrolyte can be reduced.

The substance represented by the formula (1) is not particularly limited, but ethylene carbonate, diethyl carbonate, dimethyl carbonate, vinylene carbonate, propylene carbonate or butylene carbonate is easy to obtain and handle. It is preferable to use singly or in combination of two or more.

The reforming step may be constituted by leaving the "composite electrode", "power generation element including the composite electrode" or "battery including the power generation element" as is, but more effectively. , “Composite electrode”, “power generation element including composite electrode” or “battery including the power generation element” is preferably included, and the latter requires the reforming step. The time required can also be shortened.

The solid electrolyte referred to herein is, for example, in a polymer solid electrolyte, a polymer solid electrolyte characterized in that ions are conducted by segment motion of a polymer chain represented by polyalkylene oxide. For example, a polymer such as polyacrylonitrile does not include a so-called gel electrolyte in which a large amount of a general non-aqueous electrolyte is retained. The polymer solid electrolyte includes
A plasticizer may be added for the purpose of activating the segment movement to improve the ionic conductivity or softening the solid electrolyte.

The content of the modifier may be an amount necessary and sufficient to act on the active material, and is specifically 0.01 to 10% by weight with respect to the solid electrolyte or the solid electrolyte precursor. It is preferable that the content is 0.01 to 5%, more preferably 0.01 to 3%.
More specifically, as a preliminary experiment, test electrodes with known active material amounts were placed in an electrolyte containing a sufficient amount of modifier and an electrolyte containing no modifier, and a coulomb meter was connected. It is preferable to perform the potential scanning measurement described above to obtain the amount of the modifying agent necessary for the modifying reaction in advance.

If the content of the modifier is excessive, the modifier remains in the battery after completion, so it is preferable that the content of the modifier is not excessive. That is, it is preferable that the reforming step consumes the entire amount of the modifier contained in the solid electrolyte or the solid electrolyte precursor, and the solid electrolyte battery after completion does not contain the modifier.

The reforming effect of the present invention is effective for most positive electrode active materials and negative electrode active materials, but among them, a particularly high effect is recognized when a carbonaceous material is used as the negative electrode active material. In consideration of this point, the amount of the modifier contained in the solid electrolyte or the solid electrolyte precursor used for the negative electrode composite electrode is the solid electrolyte or the solid electrolyte used for the separator portion or the solid electrolyte or the solid electrolyte used for the positive electrode composite electrode. The amount may be larger than the amount of the modifier contained in the precursor. Alternatively, the modifier may be contained only in the solid electrolyte or the solid electrolyte precursor used for the negative electrode composite electrode. For example, when a plate-like electrode such as metallic lithium is used, or when the active material is powdery and the electrode thickness is sufficiently thin, the composite electrode may not be used. Further, the modifier may be contained only in the solid electrolyte or the solid electrolyte precursor used in the separator portion regardless of whether the composite electrode is used or not.

The battery system to which the present invention can be applied is not limited, but when applied to a so-called lithium battery system including a positive electrode capable of delivering and receiving lithium ions and a negative electrode capable of delivering and receiving lithium ions, a battery having a high energy density. Is preferable because it can be

The type of solid electrolyte is not limited, and examples thereof include inorganic solid electrolytes and polymer solid electrolytes. Above all, when using a polymer solid electrolyte,
It is preferable because it has excellent flexibility, is easy to manufacture, is lightweight, and has a high degree of freedom in shape.

The solid electrolyte precursor used for the polymer solid electrolyte is preferably an acrylate monomer of polyalkylene oxide. Illustrative examples of the acrylate monomer include bifunctional or higher unsaturated monomers, and more specific examples include bifunctional (meth) acrylates {ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, adipine. acid·
Dineopentyl glycol ester di (meth) acrylate, polyethylene glycol di (meth) acrylate having a degree of polymerization of 2 or more, polypropylene glycol di (meth) acrylate having a degree of polymerization of 2 or more, polyoxyethylene /
Polyoxypropylene copolymer di (meth) acrylate, butanediol di (meth) acrylate, hexamethylene glycol di (meth) acrylate, etc.} trifunctional (meth) acrylate {trimethylolpropane tri (meth) acrylate, glycerin tri (Meth) acrylate, tri (meth) acrylate of ethylene oxide adduct of glycerin, tri (meth) acrylate of propylene oxide adduct of glycerin, ethylene oxide of glycerin, tri (meth) acrylate of propylene oxide adduct}, tetrafunctional or higher Polyfunctional (meth) acrylates {pentaerythritol tetra (meth) acrylate, diglycerin hexa (meth) acrylate, etc.}. These monomers alone or
It can be used in combination.

A monofunctional monomer may be added to the acrylate monomer for the purpose of adjusting physical properties and the like. Examples of the monofunctional monomers include unsaturated carboxylic acids {acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, vinylbenzoic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, methylenemalonic acid, Aconitic acid, etc., unsaturated sulfonic acid {styrene sulfonic acid, acrylamido-2-methylpropane sulfonic acid, etc.} or salts thereof (Li salt, Na salt, K salt, ammonium salt, tetraalkyl ammonium salt, etc.), and these Unsaturated carboxylic acid partially esterified with a C1-C18 aliphatic or alicyclic alcohol, alkylene (C2-C4) glycol, polyalkylene (C2-C4) glycol, etc. (methyl malate, monohydroxyethylmercohol) Rate, etc.), and part with ammonia, primary or secondary amines Those amidation (maleic acid monoamide, N- methyl maleate monoamide, N, N-
(Diethyl maleic acid monoamide, etc.), (meth) acrylic acid ester [ester of C1-C18 aliphatic (methyl, ethyl, propyl, butyl, 2-ethylhexyl, stearyl, etc.) alcohol and (meth) acrylic acid,
Or an ester of (meth) acrylic acid with alkylene (C2-C4) glycol (ethylene glycol, propylene glycol, 1,4-butanediol, etc.) and polyalkylene (C2-C4) glycol (polyethylene glycol, polypropylene glycol)]; (Meta)
Acrylamide or N-substituted (meth) acrylamide [(meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, etc.]; vinyl ester or allyl ester [vinyl acetate, allyl acetate, etc.]; vinyl ether or allyl Ether [butyl vinyl ether, dodecyl allyl ether, etc.]; unsaturated nitrile compound [(meth) acrylonitrile, crotonnitrile, etc.]; unsaturated alcohol [(meth) allyl alcohol, etc.]; unsaturated amine [(meth) allylamine, dimethylaminoethyl (Meth) acrylate, diethylaminoethyl (meth) acrylate, etc.];
Heterocycle-containing monomers [N-vinylpyrrolidone, vinylpyridine, etc.]; olefinic aliphatic hydrocarbons [ethylene,
Propylene, butylene, isobutylene, pentene, (C
6-C50) α-olefin and the like]; olefin-based alicyclic hydrocarbon [cyclopentene, cyclohexene, cycloheptene, norbornene and the like]; olefin aromatic hydrocarbon [styrene, α-methylstyrene, stilbene and the like];
Unsaturated imides [maleimide etc.]; halogen-containing monomers [vinyl chloride, vinylidene chloride, vinylidene fluoride, hexafluoropropylene etc.] and the like.

When applied to a lithium battery system, solid electrolysis
The electrolyte salt that constitutes the quality is not limited in any way.
There is no. For example, LiClO_Four, LiBF_Four, LiAsF
₆, LiPF₆, LiSCN, LiBr, LiI, Li₂
SO_Four, Li₂B_TenCl_Ten, NaClO_Four, NaI, Na
SCN, NaBr, KClO_Four, Lithium such as KSCN
(Li), sodium (Na) or potassium (K)
Inorganic ion salt containing one, LiCF₃SO₃, LiN (C
F₃SO₂)₂, LiN (C₂F_FiveSO₂)₂, LiN (CF₃
SO₂) (C_FourF₉SO₂), LiC (CF₃SO₂)₃, L
iC (C₂F_FiveSO ₂)₃, LiPF₃(C₂F_Five)₃, LiP
F₃(CF₃)₃, (CH₃)_FourNBF_Four, (CH₃)_FourNB
r, (C₂H_Five)_FourNClO_Four, (C₂H_Five)_FourNI, (C₃H
₇)_FourNBr, (n-C_FourH₉)_FourNClO_Four, (N-C
_FourH₉)_FourNI, (C₂H_Five)_FourN-maleate, (C₂
H_Five)_FourN-benzoate, (C₂H_Five)_FourN-pht
alate, lithium stearyl sulfonate, octyl
Lithium sulfonate, dodecylbenzene sulfonic acid lithi
Organic ionic salts such as um, etc.
Compounds used alone or in combination of two or more
Is possible.

Among them, LiN (CF ₃ SO ₂ ) ₂ , Li
N (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ S
O ₂ ), LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ S
O ₂ ) ₃ etc., such as LiN (C _n F _{2n + 1} SO ₂ ) (C _m F
_When a salt represented by _{2m + 1} SO ₂ (where n and m are natural numbers) is used, especially when applied to a polymer solid electrolyte, the effect of plasticizing the polymer is remarkably exhibited, and high ionic conductivity is exhibited. It is particularly preferable because it is possible. Furthermore, the general formula Li
_{N (C n F 2n + 1} SO 2) 1 represented by _{(C m F 2m + 1 SO} 2)
More than one salt, LiClO ₄ , LiBF ₄ , LiAs
F ₆ , LiPF ₆ , LiSCN, LiBr, LiI, Li
_It may be used by mixing with one or more kinds of salts selected from the group consisting of ₂ SO ₄ , Li ₂ B ₁₀ Cl _10, since good ionic conductivity can be exhibited even at low temperature, and self-discharge is suppressed. It is preferable in that a battery having excellent storage stability and good charge / discharge cycle performance can be provided.

An electrode composed of a lithium-containing transition metal oxide is preferably used for the positive electrode of the lithium battery, and an electrode composed of graphite is preferably used for the negative electrode. As the positive electrode active material, which is a main component of the positive electrode, it is desirable to use lithium-containing transition metal oxides, lithium-containing phosphates, lithium-containing sulfates, etc., alone or in combination. As the lithium-containing transition metal oxide, a general formula Li _y MX ₂ ,
Li _y MN _x X ₂ (M and N are metals of groups I to VIII, X is a chalcogen compound such as oxygen and sulfur), and is, for example, Li _y Co _1-x M _x O ₂ and Li _y Mn _{2. -x} M _X O ₄ (M is
Group I to VIII metals (eg Li, Ca, Cr, N
(One or more elements of i, Fe, Co and Mn are preferable)
Etc. Regarding the x value showing the substitution amount of the different element of the lithium-containing transition metal oxide, it is effective up to the maximum substitution amount, but preferably 0 ≦ x ≦ 1 from the viewpoint of discharge capacity.
Is. As for the y value indicating the amount of lithium, the maximum amount that can reversibly use lithium is effective, and preferably 0 ≦ y ≦ 2 in terms of discharge capacity. ), But is not limited thereto.

Further, other positive electrode active material may be mixed with the lithium-containing compound, and as the other positive electrode active material, CuO, Cu ₂ O, Ag ₂ O, CuS, CuSO ₄ or the like can be used. metal compounds, TiS _2, SiO _2, IV group metal compound of SnO, _{etc., V 2 O 5, V 6} O 1 2, VO x, Nb 2 O 5, Bi
Group V metal compounds such as ₂ O ₃ and Sb ₂ O ₃ , CrO ₃ and Cr ₂ O
Group VI metal compounds such as ₃ , MoO ₃ , MoS ₂ , WO ₃ and SeO ₂ , Group VII metal compounds such as MnO ₂ and Mn ₂ O ₃ , Fe ₂
O ₃ , FeO, Fe ₃ O ₄ , Ni ₂ O ₃ , NiO, CoO ₃ ,
A metal compound represented by a Group VIII metal compound such as CoO, for example, a lithium-cobalt complex oxide or a lithium-manganese complex oxide, and further disulfide, polypyrrole, polyaniline, polyparaphenylene, polyacetylene, polyacene system Conductive polymer compound such as material,
Examples include carbonaceous materials having a pseudo-graphite structure, but are not limited thereto.

As a negative electrode material of a lithium battery, lithium metal, lithium alloy (lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-) is used.
In addition to lithium metal-containing alloys such as tin, lithium-gallium, and wood alloys, alloys capable of inserting and extracting lithium, carbon materials (for example, graphite, hard carbon, low temperature calcined carbon, amorphous carbon, etc.), etc. To be Among these, graphite is preferable as a negative electrode material because it has an operating potential extremely close to that of metallic lithium, and thus self-discharge can be reduced and irreversible capacity during charge / discharge can be reduced when a lithium salt is used as an electrolyte salt. For example, artificial graphite and natural graphite are preferable.
In particular, graphite in which the surface of the negative electrode active material particles is modified with amorphous carbon or the like is desirable because it generates less gas during charging.

The analysis results of X-ray diffraction of graphite which can be preferably used are shown below: Lattice plane spacing (d ₀₀₂ ) 0.333 to 0.350 nm Crystallite size La in the a-axis direction La 20 nm or more c Axial crystallite size Lc 20 nm or more True density 2.00 to 2.25 g / cm ³

It is also possible to modify the graphite by adding metal oxides such as tin oxide and silicon oxide, phosphorus, boron and amorphous carbon. In particular, by modifying the surface of graphite by the above method, it is possible to suppress decomposition of the electrolyte and enhance the battery characteristics, which is desirable.

The powder of the positive electrode active material and the powder of the negative electrode material are
It is desirable that the average particle size is 100 μm or less.
In particular, the powder of the positive electrode active material is preferably 10 μm or less for the purpose of improving the high output characteristics of the non-aqueous electrolyte battery. A crusher or a classifier is used to obtain the powder in a predetermined shape. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a planetary ball mill, a jet mill, a counter jet mill, a swirling airflow type jet mill, a sieve and the like are used. Wet grinding in which water or an organic solvent such as hexane coexists may be used during grinding. The classification method is not particularly limited, and a sieve, an air classifier, or the like may be used for both dry and wet methods as necessary.

The positive electrode and the negative electrode may contain a conductive agent, a binder, a thickener, a filler and the like as other constituent components in addition to the main constituent components.

The conductive agent is not limited as long as it is an electron conductive material that does not adversely affect the battery performance, but usually,
Natural graphite (scaly graphite, flake graphite, earth graphite, etc.), artificial graphite, carbon black, acetylene black, Ketjen black, carbon whiskers, carbon fiber, metal (copper, nickel, aluminum, silver, gold, etc.) powder, A conductive material such as a metal fiber or a conductive ceramic material may be contained as one kind or a mixture thereof.

Of these, acetylene black is preferable as the conductive agent from the viewpoint of electron conductivity and coatability. The amount of the conductive agent added is preferably 0.1% by weight to 50% by weight, more preferably 0.5% by weight to 30% by weight, based on the total weight of the positive electrode or the negative electrode. In particular, it is desirable to grind acetylene black into ultrafine particles of 0.1 to 0.5 μm and use it because the required carbon amount can be reduced. These mixing methods are physical mixing, and ideally, they are homogeneous mixing. Therefore, a powder mixer such as a V-type mixer, an S-type mixer, a grinder, a ball mill, and a planetary ball mill can be mixed in a dry or wet manner.

The binder is usually thermoplastic resin such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM. , A polymer having rubber elasticity such as styrene-butadiene rubber (SBR) and fluororubber can be used as one kind or as a mixture of two or more kinds. The addition amount of the binder is preferably 1 to 50% by weight, and particularly preferably 2 to 30% by weight based on the total weight of the positive electrode or the negative electrode.

As the thickener, polysaccharides such as carboxymethyl cellulose, methyl cellulose and the like can be usually used as one kind or as a mixture of two or more kinds. In addition, it is desirable that the thickening agent having a functional group that reacts with lithium such as a polysaccharide is deactivated by, for example, methylating. The addition amount of the thickener is preferably 0.5 to 10% by weight, more preferably 1 to 2% by weight, based on the total weight of the positive electrode or the negative electrode.

As the filler, any material may be used as long as it does not adversely affect the battery performance. Usually, olefin polymers such as polypropylene and polyethylene, amorphous silica, alumina, zeolite, glass, carbon and the like are used. The amount of the filler added is preferably 30% by weight or less with respect to the total weight of the positive electrode or the negative electrode.

For the positive electrode and the negative electrode, the active material, the conductive agent, and the binder are mixed with an organic solvent such as N-methylpyrrolidone and toluene, and the resulting mixed solution is used as a current collector described in detail below. It is suitably prepared by applying it on the surface and drying it. Regarding the coating method, for example, roller coating such as an applicator roll, screen coating, doctor blade method, spin coating, it is desirable to be applied in any shape using a means such as bar coater, but is not limited to these It is not something that will be done.

The current collector may be any electron conductor as long as it does not adversely affect the constructed battery. For example, as the current collector for the positive electrode, aluminum, titanium,
In addition to stainless steel, nickel, baked carbon, conductive polymers, conductive glass, etc., the surface of aluminum, copper, etc. is carbon, nickel, titanium, silver, etc. for the purpose of improving adhesion, conductivity, and oxidation resistance. The product treated with can be used. As the negative electrode current collector, in addition to copper, nickel, iron, stainless steel, titanium, aluminum, baked carbon, conductive polymer, conductive glass, Al-Cd alloy, adhesiveness,
For the purpose of conductivity and resistance to reduction, a material such as copper whose surface is treated with carbon, nickel, titanium, silver or the like can be used. It is also possible to oxidize the surface of these materials.

With respect to the shape of the current collector, in addition to foil shape, film shape, sheet shape, net shape, punched or expanded material, lath material, porous material, foamed material, fiber group forming material, etc. are used. To be There is no particular limitation on the thickness, but 1
Those having a thickness of up to 500 μm are used. Among these current collectors, the positive electrode is an aluminum foil having excellent oxidation resistance, and the negative electrode is a reduction resistance, and excellent in electrical conductivity, and an inexpensive copper foil, nickel foil, iron foil, and It is preferable to use alloy foils containing some of them. Further, it is preferable that the foil has a rough surface of 0.2 μmRa or more,
Thereby, the adhesion between the positive electrode active material or the negative electrode active material and the current collector becomes excellent. Therefore, it is preferable to use the electrolytic foil because it has such a rough surface. In particular,
The electrolytic foil which has been subjected to the edging treatment is the most preferable. further,
When the foil is coated on both sides, it is desired that the surface roughness of the foil is the same or almost the same.

Examples of the material of the outer package include nickel-plated iron, stainless steel, aluminum, and a metal resin composite film. For example, a metal-resin composite film having a structure in which a metal foil is sandwiched between resin films may be used. Specific examples of the metal foil include aluminum, iron, nickel, copper, stainless steel, titanium,
The foil is not limited as long as it is a foil without pinholes such as gold or silver, but a lightweight and inexpensive aluminum foil is preferable. As the resin film on the outside of the battery, a resin film having excellent puncture strength such as polyethylene terephthalate film or nylon film can be heat-sealed as the resin film on the inside of the battery such as polyethylene film or nylon film. A film that is present and has solvent resistance is preferable.

The structure of the battery is not particularly limited, and a coin battery or a button battery having a positive electrode, a negative electrode and a single-layer or multi-layer separator, and a cylindrical battery having a positive electrode, a negative electrode and a roll-shaped separator. Examples thereof include prismatic batteries and flat batteries.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail based on the following examples.

Example 1 A triacrylate (molecular weight 8,000) monomer having a copolymer of ethylene oxide and propylene oxide as a main chain was added as an electrolyte salt to 1 mo.
LiN (CF ₃ SO ₂ ) ₂ in an amount of 1 / l was dissolved to obtain a solid electrolyte precursor. The solid electrolyte precursor and ethylene carbonate as a modifier were mixed at a weight ratio of 98: 2 to obtain a “solid electrolyte precursor containing a modifier”.

Natural graphite as a negative electrode active material and polyvinylidene fluoride as a binder were mixed in a weight ratio of 95: 5. Here, the polyvinylidene fluoride is NMP (N
-Methylpyrrolidone) solution. The weight ratio is a solid content conversion value of polyvinylidene fluoride. Furthermore N
MP was added to obtain a negative electrode paste. The negative electrode paste was applied to an electrolytic copper foil as a negative electrode collector and dried to obtain N.
MP was volatilized and it was set as the negative electrode plate. The “solid electrolyte precursor containing a modifier” is applied onto the negative electrode plate, and 133 Pa
By leaving it under reduced pressure for 16 hours, the "solid electrolyte precursor containing a modifier" was impregnated into the voids between the negative electrode active material particles in the negative electrode plate. The negative electrode plate impregnated with the solid electrolyte precursor containing a modifier was irradiated with an electron beam having an absorbed dose of 100 Gy to form a negative electrode.

LiCoO ₂ as a positive electrode active material, acetylene black as a conductive material, and polyvinylidene fluoride as a binder were mixed in a weight ratio of 90: 5: 5. Here, the polyvinylidene fluoride was used as an NMP solution. The weight ratio is a solid content conversion value of polyvinylidene fluoride. Further, NMP was added to obtain a positive electrode paste. The positive electrode paste was applied to an aluminum foil as a positive electrode current collector, and NMP was volatilized by drying to obtain a positive electrode plate. Applying the solid electrolyte precursor on the positive electrode plate,
By leaving it under a reduced pressure of 133 Pa for 16 hours, the solid electrolyte precursor was impregnated into the gaps between the positive electrode active material particles in the positive electrode plate. After irradiating the positive electrode plate impregnated with the solid electrolyte precursor with an electron beam with an absorbed dose of 60 Gy, the solid electrolyte precursor is further thinly applied to form a separator layer on the surface of the positive electrode, and an electron beam with an absorbed dose of 40 Gy is applied. Was irradiated. As a result, a separator-integrated positive electrode was obtained.

After the separator-integrated positive electrode and the negative electrode are bonded together to form a battery, a 0.0
The voltage between terminals is 4.2 at the current density of 5 It (20 hour rate).
Constant current charging was performed until V was reached. A solid electrolyte battery was produced by the above operation.

Example 2 99.99: 0.0 of solid electrolyte precursor and ethylene carbonate as a modifier
Mixed in a weight ratio of 1 to give a "modifying solid electrolyte precursor"
Then, a solid electrolyte battery was produced in the same manner as in Example 1 except that this was used.

Example 3 A solid electrolyte precursor and ethylene carbonate as a modifier were mixed at a weight ratio of 90:10 to obtain a “modifier-containing solid electrolyte precursor”, which was used. A solid electrolyte battery was produced in the same manner as in Example 1 except for.

(Example 4) A solid electrolyte precursor and diethyl carbonate as a modifier were mixed at a weight ratio of 98: 2 to prepare a "solid electrolyte precursor containing a modifier", which was used. A solid electrolyte battery was produced in the same manner as in Example 1 except for.

(Example 5) A solid electrolyte precursor and dimethyl carbonate as a modifier were mixed in a weight ratio of 98: 2 to prepare a "modifier-containing solid electrolyte precursor", which was used. A solid electrolyte battery was produced in the same manner as in Example 1 except for.

(Comparative Example 1) The same procedure as in Example 1 was repeated except that a solid electrolyte precursor containing no modifier was used in place of the "modifier-containing solid electrolyte precursor". A solid electrolyte battery was produced.

(Battery Performance Test) Using the solid electrolyte batteries according to Examples 1 to 4 and Comparative Example 1, a charge / discharge cycle test was conducted. Since the solid electrolyte batteries according to Examples 1 to 4 and Comparative Example 1 were in a charged state by the reforming process, the charge / discharge test was started from discharging. The discharge was a constant current discharge with a current value of 0.05 It (20 hour rate) and an end voltage of 2.7 V, and the charging was a constant current charge with a current value of 0.05 It (20 hour rate) and an end voltage of 4.2 V. . 1,
Table 1 shows the discharge capacities at the 3rd, 6th and 10th cycles as a percentage of the battery design capacity.

[0060]

[Table 1]

The solid electrolyte batteries according to Examples 1 to 4 and Comparative Example 1 were separately prepared, the batteries were disassembled, and GC-MASS was used.
The presence or absence of the modifier remaining in the battery was examined by analysis.
As a result, the component of the modifier was detected in the battery of Example 3, but the component of the modifier was not detected in the other batteries. The results are also shown in Table 1.

Looking at the transition of the discharge capacity from the initial to the 10th cycle accompanying the charge / discharge cycle, the initial discharge capacity is almost the same, but in the comparative battery 1, the discharge capacity gradually decreases with the lapse of cycles. In contrast, the present invention batteries 1 to
In No. 5, on the contrary, there is a remarkable difference in that they are increasing. The cause of this is not necessarily clear, but the charging operation performed during the reforming process decomposes the modifying agent on the surface of the carbonaceous material used as the negative electrode active material to form a low-resistance coating film. It is considered that the state of the interface between the solid electrolyte and the negative electrode active material particles became good, and the charge / discharge cycle characteristics were improved.

[0063]

As described above, according to the present invention, there is provided a method for producing a solid electrolyte battery comprising a positive electrode, a negative electrode and a solid electrolyte, wherein a solid modifier containing a substance represented by the formula (1) is used. A solid electrolyte battery having excellent battery performance, in which the interface resistance between the active material and the solid electrolyte is reduced because the battery is characterized by being contained in an electrolyte or a solid electrolyte precursor and undergoing a reforming process. it can.

Further, since the modifier is contained in an amount of 0.01% by weight or more with respect to the solid electrolyte or the solid electrolyte precursor, the effect of reducing the interfacial resistance between the active material and the solid electrolyte is obtained. Can be sufficient.

Further, the modifier is contained in an amount of less than 10% by weight based on the solid electrolyte or the solid electrolyte precursor, or the solid electrolyte battery is represented by (Formula 1)
Since it is characterized by not containing the substance indicated by
It is possible to provide a solid electrolyte battery in which the modifier does not remain in the battery and there is no risk of liquid leakage.

Further, the solid electrolyte battery is characterized by comprising a positive electrode capable of giving and receiving lithium ions and a negative electrode capable of giving and receiving lithium ions. Therefore, a solid electrolyte battery having a high energy density is obtained. Can be provided.

Further, since the solid electrolyte battery is characterized by including the negative electrode using the carbonaceous material, it is possible to provide the solid electrolyte battery having good charge / discharge cycle performance.

Since the solid electrolyte is a polymer solid electrolyte, it is possible to provide a thin and lightweight solid electrolyte battery having good charge / discharge cycle performance.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H029 AJ03 AJ05 AJ06 AJ11 AJ15                       AK02 AK03 AK05 AK16 AK18                       AL06 AL07 AL08 AL12 AM03                       AM07 AM11 AM16 CJ11 DJ09                       EJ04 EJ12 HJ01                 5H050 AA07 AA08 AA12 AA20 BA17                       CA02 CA08 CA09 CA11 CA20                       CA29 CB07 CB08 CB09 CB12                       DA09 DA13 EA10 EA21 EA24                       GA11 HA01

Claims (7)

[Claims] 1. A method for producing a solid electrolyte battery comprising a positive electrode, a negative electrode and a solid electrolyte, wherein a modifier comprising a substance represented by (Formula 1) is added to a solid electrolyte or a solid electrolyte precursor. A method for manufacturing a solid electrolyte battery, which comprises completing the battery through a quality process. O = C (OR) (OR ') (Formula 1) (wherein R and R'are hydrocarbons and may be the same or different, or they are bonded to each other to form a ring. You may have.) 2. The method for producing a solid electrolyte battery according to claim 1, wherein the modifier is contained in an amount of 0.01% by weight or more and less than 10% by weight with respect to the solid electrolyte or the solid electrolyte precursor. . 3. The solid electrolyte battery does not contain a substance represented by (Formula 1), and the solid electrolyte battery according to claim 1 or 2.
A method for manufacturing the solid electrolyte battery according to 1. 4. A positive electrode capable of delivering and receiving lithium ions, and a negative electrode capable of delivering and receiving lithium ions.
4. The method for manufacturing a solid electrolyte battery according to any one of 3 above. 5. The method for producing a solid electrolyte battery according to claim 1, further comprising a negative electrode made of a carbonaceous material. 6. The method for producing a solid electrolyte battery according to claim 1, wherein the solid electrolyte is a polymer solid electrolyte. 7. A solid electrolyte battery manufactured by the method for manufacturing a solid electrolyte battery according to claim 1.