JPH1186911A - Polymer battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer battery in which impedance is low and the change with the lapse of time is small. SOLUTION: In a battery, a polymer solid electrolyte consisting of a crosslinked polymer matrix and an electrolytic salt is compounded to be used as a positive electrode and/or a negative electrode, wherein a layer of a polymer solid electrolyte comprising a thermoplastic polymer and a nonaqueous electrolysis solution is formed between the positive electrode and the negative electrode. The composite electrode preferably contains a nonaqueous solvent. Moreover, the composite electrode is preferably made by impregnating a solution which comprises a polymerizable monomer and an electrolytic salt and has preferably a viscosity of 100 cP car less in an electrode formed by molding an electrode active material with a binder, and polymerizing the polymerizable monomer by an energy ray irradiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polymer battery.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable progress in miniaturization and weight reduction of electronic devices. Particularly in the OA field, the size and weight of electronic devices have been reduced from desktop type to laptop type and notebook type. In addition, the field of new small electronic devices such as electronic notebooks and electronic still cameras has emerged, and furthermore, in addition to miniaturization of conventional hard disks and floppy disks, development of memory cards has been advanced. In the wave of the miniaturization and weight reduction of such electronic devices, the batteries that support these powers also have high energy density,
High performance such as high output is required.

[0003] Regarding the shape of the battery, various types of prismatic batteries that can be adapted to the shape of equipment have been developed from conventional cylindrical ones, and thinner flat batteries have been developed. This flat battery is generally called a polymer battery, uses a solid electrolyte for the electrolyte, has high reliability, such as no liquid leakage, and uses a film for the exterior, so the shape is more than that of a conventional battery. It also has the advantage that it is thinner and can be made freely according to the equipment used.

[0004]

As the solid electrolyte, a solid polymer electrolyte comprising a thermoplastic polymer, an electrolyte salt and a high-boiling solvent such as propylene carbonate has been used. This polymer solid electrolyte is usually obtained by mixing a thermoplastic polymer with an electrolytic solution and cooling the heated and melted pre-solution. This pre-solution melted by heating has the disadvantage that it generally has a high viscosity, so that it does not penetrate into the battery even if it is to be compounded into the electrode, and the resistance at the interface between the electrode and the polymer solid electrolyte increases. I have.

Although it is possible to reduce the viscosity of the pre-solution by using a diluent, it is necessary to remove excess diluent by vacuum treatment or the like when the pre-solution is cooled. After preparing a polymer solid electrolyte film and bonding it between the positive and negative electrodes, it is possible to use the polymer solid electrolyte by melting it by heating, but it is absolutely necessary to use the interface between the electrode and the polymer electrolyte. Resistance increases.

[0006] By mixing an electrode active material with a pre-solution at the time of electrode preparation and forming the mixture into an electrode, the interface resistance between the electrode active material and the solid polymer electrolyte can be reduced (for example, Japanese Patent Application Laid-Open No. 57-27567). ). However, since this electrode is melted when heated again, for example, when an internal short circuit occurs in the battery, the electrode is melted by Joule heat due to the short circuit current, and the internal short circuit is further accelerated, resulting in a dangerous state.

A method for obtaining a crosslinked gel by reacting a mixture of a polymerizable monomer such as acryloyl-modified polyethylene oxide with an electrolytic solution as a polymer solid electrolyte by irradiating ultraviolet rays is disclosed in, for example, JP-A-63-94501. It has been disclosed. This crosslinked gel has ionic conductivity almost equal to that of the electrolytic solution, and the mixture of the electrolytic solution and the polymerizable monomer is equivalent to or higher than the electrolytic solution by selecting the polymerizable monomer. Because it can be adjusted to a low viscosity, the permeability to the electrode is high,
Since the crosslinked gel and the electrode can be combined in the same interface state as in the electrolytic solution, the interface resistance can be kept low.

However, in the production of a polymer battery, a positive electrode and a negative electrode in which a crosslinked gel is compounded are attached to each other. However, the impedance of the battery is considerably higher than a design value and tends to increase with time. There were many. Japanese Patent Application Laid-Open No. 5-151999 proposes that an electrode contains an electrolyte and is bonded to a polymer solid electrolyte, but the electrolyte contained in the electrode is gradually absorbed by the polymer solid electrolyte. Therefore, the interface resistance increases with the passage of time.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a polymer battery having a low impedance and a small change with time.

[0010]

Means for Solving the Problems The inventors of the present invention have analyzed the reason why the impedance of a polymer battery in which a cathode and an anode each having a crosslinked gel are combined is high, and found that a crosslinked gel layer on the surface of the cathode and Due to poor adhesion and adhesion with the crosslinked gel layer on the negative electrode surface, unless it is in a pressurized state,
It was confirmed that the impedance was increased because the portion where the crosslinked gel layers were in contact with each other was small.

The inventors of the present invention have conducted intensive studies to lower the impedance of a polymer battery in which a positive electrode and a negative electrode each having a crosslinked gel are combined, and as a result, the crosslinked gel, a thermoplastic polymer and a non-aqueous electrolyte have been studied. Focusing on good adhesion and adhesion with polymer solid electrolyte composed of liquid,
The present invention has found that by providing a polymer solid electrolyte layer composed of a thermoplastic polymer and a non-aqueous electrolyte between a positive electrode and a negative electrode in which a crosslinked gel is compounded, the impedance of a polymer battery can be significantly reduced. Reached.

That is, in the polymer battery according to the first aspect of the present invention, as the electrode, a positive electrode and / or a composite polymer solid electrolyte comprising a crosslinked polymer matrix and an electrolyte salt are combined.
Alternatively, in a polymer battery using a negative electrode, a polymer solid electrolyte layer including a thermoplastic polymer and a non-aqueous electrolyte is provided between the positive electrode and the negative electrode.

According to a second aspect of the present invention, in the first aspect, the positive electrode and / or the negative electrode in which the solid polymer electrolyte comprising the crosslinked polymer matrix and the electrolyte salt is mixed contain a non-aqueous solvent. It is characterized by the following.

According to a third aspect of the present invention, there is provided a polymer battery according to the first or second aspect, wherein the positive electrode and / or the negative electrode in which the solid polymer electrolyte comprising the crosslinked polymer matrix and the electrolyte salt is combined, at least the electrode active material is a binder. The electrode formed by impregnating a solution composed of at least a polymerizable monomer and an electrolyte salt, and then reacting with the polymerizable monomer.

According to a fourth aspect of the present invention, in the third aspect, the viscosity of the solution comprising the polymerizable monomer and the electrolyte salt is 100 cP or less.

According to a fifth aspect of the present invention, in the polymer battery according to the third or fourth aspect, the polymerizable monomer is represented by a monomer represented by the following formula [1] and / or by the following formula [2]. It is characterized by containing a monomer.

[0017]

Embedded image (Wherein, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrocarbon group or a group containing a heterocyclic ring, and n represents an integer of 1 or more)

[0018]

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

A polymer battery according to a sixth aspect is characterized in that the reaction of the polymerizable monomer in the third, fourth or fifth aspect is a polymerization reaction caused by irradiation with energy rays.

The polymer battery according to claim 7 is the polymer battery according to any one of claims 1 to 6, wherein the thermoplastic polymer is polyacrylonitrile, polymethacrylate, polyvinylidene fluoride or polyalkylene oxide, or It is a copolymer of vinylidene fluoride and polyhexafluoropropylene.

[0021]

Embodiments of the present invention will be described below. The electrode used in the polymer battery of the present invention is an electrode active material, acetylene black used as required, a conductive agent such as graphite, a binder such as polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, and polypropylene, and a current collector. Consists of

As the current collector, conductive foil such as aluminum, copper, stainless steel, etc., wire mesh, expanded metal,
Punched metal, woven fabric using carbon fiber, sheet, foamed metal, conductive film coated with SnO ₂ or TiO ₂ and the like can be given.

As the positive electrode active material of the present invention, MnO ₂ , M
n ₂ O ₃ , CoO ₂ , NiO ₂ , TiO ₂ , V ₂ O ₅ ,
V ₃ O ₈ , Cr ₂ O ₃ , Fe ₂ (SO ₄ ) ₃ , Fe
₂ (MoO ₂ ) ₃ , Fe ₂ (WO ₂ ) ₃ , TiS ₂ , M
oS ₂ , LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄
Transition metal chalcogen compounds; J. Visco,
et al. , Mol. Cryst. Liq. Crys
t. , 190, 185 (1990), conductive polymers such as polyaniline, polyacetylene, polypyrrole, polythiophene, polyalkylthiophene, polycarbazole, polyazulene, polydiphenylbenzidine, and carbon bodies. From the viewpoint of energy density, transition metal chalcogen compounds are preferred.

When the electrode of the present invention is used as a negative electrode, the electrode active material may be a lithium alloy composed of Li and Al, Si, Pb, etc., a metal oxide such as SnO ₂ , SnO, TiO ₂ , NbO _2, or polyacetylene. , Polyporaphenylene,
Conductive polymers such as polythiophene, polyalkylthiophene and polypyridine and natural graphite, coal coke,
Carbon materials such as petroleum coke, pyrolytic carbon from organic compounds as raw materials, and carbon bodies obtained by baking natural and synthetic polymers are used. Among these, carbon materials are used in terms of cycle life and energy density. Is most preferred.

The crosslinked polymer matrix constituting the solid polymer electrolyte comprising the crosslinked polymer matrix and the electrolyte of the polymer battery of the present invention is a crosslinked polymer having an ionic dissociating group in the matrix. The solid polymer electrolyte comprising the crosslinked polymer matrix and an electrolyte salt preferably contains a non-aqueous solvent.
Due to the presence of the non-aqueous solvent, the ionic conductivity of the solid polymer electrolyte is substantially equal to that of the electrolytic solution, and the impedance of the polymer battery can be made equal to the case where the electrolytic solution is used for the electrolyte.

The composite of the polymer solid electrolyte comprising the crosslinked polymer matrix and the electrolyte salt and the electrode can be performed by laminating the electrode and the polymer solid electrolyte film. When an electrolyte salt and a pre-solution comprising a non-aqueous solvent used as necessary are penetrated into the electrode, and a polymerization reaction is caused to cause a complex between the electrode and the polymer solid electrolyte,
Since the interface between the electrode and the solid polymer electrolyte is substantially in the same state as that in the electrolytic solution, the interface resistance can be greatly reduced, which is preferable.

In order to allow the pre-solution to penetrate the electrode efficiently, the viscosity of the pre-solution is preferably 100 cP or less, particularly preferably 80 cP or less. When the viscosity exceeds 100 cP, it is difficult to efficiently infiltrate the pre-solution into the pores inside the electrode, and this increases the impedance of the polymer battery, which is not preferable. Also, in order to allow the pre-solution to penetrate the electrode efficiently, it is effective to lower the surface tension of the pre-solution. As a means for reducing the surface tension, the addition of a surfactant such as a silicon compound is effective.

The polymerization reaction for preparing the polymer solid electrolyte comprising the crosslinked polymer matrix and the electrolyte salt of the polymer battery of the present invention includes a thermal polymerization reaction and a polymerization by irradiation with energy rays such as ultraviolet rays, electron beams, and X-rays. Although a reaction and the like can be exemplified, a polymerization reaction by irradiation with energy rays which has a fast polymerization reaction and a small change in the composition of the polymer solid electrolyte is preferable.

The polymerizable monomer for constituting the polymer solid electrolyte comprising the crosslinked polymer matrix and the electrolyte salt of the polymer battery of the present invention includes, in the molecule, oxygen atoms, nitrogen atoms, sulfur atoms and the like other than carbon. Those containing a hetero atom are used. In the solid electrolyte obtained by dissolving the electrolyte salt in the polymerizable compound containing these heteroatoms, or dissolving the polymerizable compound in a non-aqueous electrolyte and performing a polymerization reaction, the heteroatoms ionize the electrolyte salt. It is considered that they have the function of promoting the ionic conductivity of the solid electrolyte and also improving the strength of the solid electrolyte.

The kind of the polymerizable compound used in the present invention is not particularly limited, and includes those obtained by causing a polymerization reaction such as thermal polymerization and actinic ray polymerization.
Particularly, those showing photopolymerizability by actinic rays are preferable. Examples of the thermal polymerization reaction include a polymerization reaction using an epoxy group or an acrylate group in addition to the urethane reaction, and the urethane reaction is preferable. Examples of the actinic ray polymerization reaction include a polymerization reaction with an unsaturated carboxylic acid ester, a polyene / polythiol mixture and a crosslinkable macromer (organic silane, polyisothianaphthene, etc.). This is a reaction with a polythiol mixture.

Hereinafter, the polymerization reaction of an unsaturated carboxylic acid ester, the polymerization reaction of a polyene / polythiol mixture, and the polyurethane conversion reaction, which are particularly excellent as polymerization reactions in an electrolytic solution, will be described in detail. In this specification, (meth) acrylate means acrylate or methacrylate, and (meth) acryloyl group means acryloyl group or methacryloyl group.

The polymerization reaction for obtaining the solid electrolyte of the present invention is preferably an active light polymerization reaction which is a low-temperature process in order to avoid thermal decomposition of the electrolyte. Examples of the actinic ray-polymerizable compound include (meth) acrylate and a combination of a polyene and a polythiol. Examples of the (meth) acrylate include monofunctional and polyfunctional (meth) acrylates. A polymer matrix using a monofunctional (meth) acrylate is infusible by ionic crosslinking via an electrolyte salt, but is preferably crosslinked with a polyfunctional (meth) acrylate because stability is increased.

As the monofunctional acrylate, alkyl (meth) acrylate [methyl (meth) acrylate,
Butyl (meth) acrylate, trifluoroethyl (meth) acrylate, etc.], alicyclic (meth) acrylate [tetrahydrofurfuryl (meth) acrylate, etc.],
Hydroxyalkyl (meth) acrylate [hydroxyethyl acrylate, hydroxypropyl acrylate, etc.], hydroxypolyoxyalkylene (oxyalkylene group preferably has 1 to 4 carbon atoms) (meth) acrylate [hydroxypolyoxyethylene (meth) acrylate, hydroxy Polyoxypropylene (meth) acrylate, etc.] and alkoxy (alkoxy group preferably has 1 to 4 carbon atoms) (meth) acrylate [methoxyethyl acrylate, ethoxyethyl acrylate, phenoxyethyl acrylate, etc.].

Examples of polyfunctional (meth) acrylates include UV or EB curing technology (published by Sogo Gijutsu Center), pp. 142-152, tri-functional or more of photo-gravity monomers and photo-polymerizable prepolymers. And a prepolymer [trimethylolpropane tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

Among the acrylates, compounds having a general formula represented by the following [Chemical Formula 1] having a molecular weight of less than 500 and those having a structure represented by the general formula [Chemical Formula 2] are particularly preferable.

[0036]

Embedded image (Wherein, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrocarbon group or a group containing a heterocyclic ring, and n represents an integer of 1 or more)

[0037]

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

In the above [Chemical Formula 1], R ₂ represents a hydrocarbon group or a group containing a heterocyclic ring. In this case, the hydrocarbon group includes aliphatic and aromatic hydrocarbon groups. Examples of the aliphatic hydrocarbon group include those having 1 to 1 carbon atoms such as methyl, ethyl, propyl, butyl, hexyl, and octyl.
0, preferably 1 to 5. Further, as the aromatic hydrocarbon group, phenyl, tolyl, xylyl,
Examples include naphthyl, benzyl, phenethyl and the like. The group containing a heterocyclic ring includes various heterocyclic groups containing a heteroatom such as oxygen, nitrogen, and sulfur. Examples of such a group include furfuryl and tetrahydrofurfuryl.

Specific examples of the acrylate represented by the above [formula 1] include alkyl ethylene glycol acrylate [methyl ethylene glycol acrylate, ethyl ethylene glycol acrylate, propyl ethylene glycol acrylate, etc.], phenyl ethylene glycol acrylate, alkyl propylene glycol acrylate [ Ethyl propylene glycol acrylate, butyl propylene glycol acrylate, etc.], and an alkylene glycol acrylate having a heterocyclic ring [furfuryl ethylene glycol acrylate, tetrahydrofurfuryl ethylene glycol acrylate, furfuryl propylene glycol acrylate, tetrahydrofurfuryl propylene glycol acrylate, etc.]. .
The molecular weight of these acrylates represented by Chemical Formula 1 is usually less than 500, but is more preferably 300 or less.
When the acrylate has a molecular weight of 500 or more, the non-aqueous solvent is easily leached from the obtained solid electrolyte.

The heterocycle contained in the (meth) acrylate represented by the above [Formula 2] is not particularly limited. In this case, examples of the group containing a heterocycle include a residue of a heterocycle containing a heteroatom such as oxygen, nitrogen, and sulfur, such as a furfuryl group and a tetrahydrofurfuryl group. Examples of the (meth) acrylate represented by the above [Formula 2] include furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and the like. Of these, furfuryl acrylate and tetrahydrofurfuryl acrylate are preferred. The compound represented by Chemical Formula 1 or Chemical Formula 2 may be used alone,
More than one kind can be mixed and used.

By using a polyfunctional unsaturated carboxylic acid ester in combination with the compound represented by Chemical formula 1 or Chemical formula 2, an ideal solid electrolyte can be obtained in terms of both elastic modulus and ionic conductivity. Examples of the polyfunctional unsaturated carboxylic acid ester include those having two or more (meth) acryloyl groups. Preferable specific examples of these include a photopolymerizable monomer and a photopolymerizable prepolymer described in “UV and EB curing technology” (published by Sogo Gijutsu Center), pp. 142-152. Polymers [diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc.], but trifunctional (meth) acrylate It is most preferable in that it provides a solid electrolyte having excellent liquid properties, ionic conductivity, and strength.

The proportion of the compounds represented by the formulas (1) and (2) or the unsaturated carboxylic acid ester containing the same as a main component is 50% by weight or less, preferably 5 to 40% by weight, based on the nonaqueous electrolyte. % By weight, more preferably 10 to 30% by weight
It is. Outside this range, the ionic conductivity and strength of the solid electrolyte are reduced. When a polyfunctional unsaturated carboxylic acid ester is used in combination with the compounds of [Chemical Formula 1] and [Chemical Formula 2], the addition amount of the polyfunctional unsaturated carboxylic acid ester is preferably 4% by weight or less based on the non-aqueous electrolyte. Is 0.05 to 2% by weight, especially when a trifunctional unsaturated carboxylic acid ester is used in combination, 2% by weight or less, preferably 0.05 to 0.5% by weight.
A solid electrolyte excellent in ionic conductivity and strength can be obtained with a small addition amount of weight%.

By using such a polyfunctional unsaturated carboxylic acid ester in combination, it is possible to obtain a solid electrolyte which is more excellent in ionic conductivity and strength. On the other hand, if the combined amount of the polyfunctional unsaturated carboxylic acid ester is too large, the obtained solid electrolyte does not show properties as a viscoelastic body, lacks flexibility, and is liable to cracks due to external force.

Examples of the polymerization initiator for the compounds represented by the formulas [1] and [2] or the unsaturated carboxylic acid ester containing the same as a main component include carbonyl compounds and benzoins (benzoin, benzoin methyl ether, benzoin ethyl ether). , Ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, α-methylbenzoin, α-phenylbenzoin, etc., anthraquinones (anthraquinone, methylanthraquinone, chloranthraquinone, etc.), and other compounds (benzyl, diacetyl, acetophenone) , Benzophenone, methylbenzoylformate, etc.), sulfur compounds (diphenyl sulfide, dithiocarbamate, etc.), polycondensed ring hydrocarbon halides (α-chloromethylna) Tarin, etc.), pigments (acrylic flavin, fluorescein, etc.), metal salts (iron chloride, silver chloride, etc.), onium salts (p-methoxybenzenediazonium, hexafluorophosphate, diphenyliodonium, triphenylsulfonium, etc.) ) And the like. These can be used alone or as a mixture of two or more.

Preferred photopolymerization initiators are carbonyl compounds, sulfur compounds and onium salts. If necessary, a thermal polymerization initiator (azobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, ethyl methyl ketone peroxide, etc.) can be used in combination, and dimethylaniline, cobalt naphthenate, sulfinic acid, mercaptan, etc. Can be used in combination. Further, a sensitizer and a storage stabilizer can be used together if necessary.

Specific examples of the sensitizer and the storage stabilizer include:
Among the sensitizers and storage stabilizers described on pages 158 to 159 of "UV and EB curing technology (published by Sogo Gijutsu Center)", the former includes urea nitrile compounds (N, N-disubstituted-p- Aminobenzonitrile and the like, and phosphorus compounds (tri-n-butylphosphine and the like) are preferable, and as the latter, quaternary ammonium chloride, benzothiazole and hydroquinone are preferable.

The amount of the polymerization initiator to be used is generally 0.1 to 10% by weight, preferably 0.5 to 7% by weight, based on the total unsaturated carboxylic acid ester. Outside this range, an appropriate reactivity cannot be obtained. The amount of the sensitizer and the storage stabilizer used is usually based on 100 parts by weight of the total unsaturated carboxylic acid ester.
0.1 to 5 parts by weight.

In the present invention, the solidification of the electrolyte is carried out by injecting a compound represented by the following formula [1] or [2] or a non-aqueous electrolyte containing an unsaturated carboxylic acid ester containing the compound as a main component into a sealed container. Alternatively, it is achieved by coating on a support (eg, film, metal, metal oxide, glass, etc.) and then polymerizing with heat or actinic rays.
As the actinic rays, light, ultraviolet rays, electron beams, and X-rays can be usually used. Of these, preferred are 100 to 80
It is an active light beam having a main wavelength of 0 nm.

The polymerization reaction of a polyene / polythiol mixture is basically as shown in the following [Chemical Formula 3].

[0050]

Embedded image RSH → RSＨ + H ・ RS ・ + CH ₂ ＣＨCH—CH ₂ R ′ → RS-CH ₂ —C
H—CH ₂ R ′ RSH → RS—CH ₂ —CH ₂ —CH ₂ R ′ + RS · (where R and R ′ are organic groups such as an alkyl group)

The polyene includes a polyallyl ether compound and a polyallyl ester compound. Examples of polyallyl ether compounds include substituted and unsubstituted allyl alcohols with epoxy compounds (ethylene oxide,
Compounds to which propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide, epihalohydrin, allyl glycidyl ether, etc. are added. Of these, preferred are compounds obtained by adding ethylene oxide and propylene oxide to substituted or unsubstituted allyl alcohol.

Examples of the polyallyl ester compound include reaction products of allyl alcohol or the above-mentioned polyallyl ether compound with carboxylic acid. Examples of carboxylic acids include aliphatic, alicyclic, and aromatic mono- and polycarboxylic acids [acetic acid, propionic acid, butyric acid, octanoic acid, lauric acid, stearic acid, oleic acid, benzoic acid, and other monocarboxylic acids. Acid (C1-20); dicarboxylic acids such as adipic acid and phthalic acid]. Of these, preferred are reaction products of a polyallyl ether compound and a polycarboxylic acid. Examples of the polythiol include liquid polysulfide; aliphatic, alicyclic, and aromatic polythiol compounds; and mercaptocarboxylic acid esters. Examples of the liquid polysulfide include the Thiokol LP series (Toray Thiokol Co., Ltd.). Of these, those having an average molecular weight of 400 or less are preferred.

Examples of the aliphatic, alicyclic and aromatic polythiol compounds include methane (di) thiol and ethane (di) thiol. Examples of the mercaptocarboxylic acid ester include a compound obtained by an esterification reaction between a mercaptocarboxylic acid and a polyhydric alcohol or a transesterification reaction between a mercaptocarboxylic acid alkyl ester and a polyhydric alcohol. Examples of mercaptocarboxylic acids include 2-mercaptoacetic acid and 3-mercaptopropionic acid.

Examples of polyhydric alcohols include ethylene glycol, trimethylolpropane, glycerin, pentaerythritol, sucrose, and alkylene oxide adducts thereof (ethylene oxide adduct, propylene oxide adduct, butylene oxide adduct). Can be Preferable polyhydric alcohols are trihydric or higher polyhydric alcohols that do not contain an alkylene oxide adduct.

Examples of mercaptocarboxylic acid alkyl esters include 2-mercaptoacetic acid ethyl ester and 3-mercaptoacetic acid ethyl ester.
And methyl mercaptopropionate. Preferred among the polythiols are liquid polysulfide and mercaptocarboxylic acid esters.
As the polymerization initiator for the reaction mixture of polyethylene / polythiol, the same polymerization initiator as described for the polymerization of unsaturated carboxylic acid esters is used.

Examples of the polymerizable compound that causes a thermal polymerization reaction include a combination of a polyisocyanate forming a polyurethane with a polyol and / or a crosslinking agent, and a prepolymerized product thereof. Examples of the polyol include polyols described in "Polyurethane Resin Handbook" (published by Nikkan Kogyo Shimbun), pp. 99-117, of which alkylene oxide (ethylene oxide, propylene oxide, tetrahydrofuran, etc.) is formed by polymerization. Polyoxyalkylene polyols having a melting point of 10 ° C. or less are preferred.

In this case, the oxyalkylene group may be used alone or in combination of two or more. In particular, a polyoxyalkylene polyol obtained by copolymerizing ethylene oxide and propylene oxide is preferable. Further, the polyoxyalkylene polyol may be a mixture of two or more kinds. The melting point of the polyoxyalkylene polyol is usually 10C or less, preferably 0C to -60C. If the melting point exceeds 10 ° C., the ionic conductivity decreases due to its crystallinity. The hydroxyl value of the polyoxyalkylene polyol is usually 84 or less, preferably 60 or less. Hydroxyl value is 8
If it exceeds 4, the ionic conductivity of the solid electrolyte decreases.

As the polyisocyanate, tolylene diisocyanate, 4,4'-metaphenylene diisocyanate, isophorone diisocyanate, and prepolymers thereof are preferable among the polyisocyanates described in the above-mentioned pages 90-98. The content ratio of the NCO group is usually 48% by weight or less, preferably 40% by weight or less. When the content ratio of the NCO group exceeds 48% by weight, the ionic conductivity of the solid electrolyte decreases.

As the crosslinking agent, the above-mentioned book, pages 122 to 1
Among the crosslinking agents described on page 23, water can be used in addition to polyhydric alcohols and polyamines. Of these, polyhydric alcohols such as ethylene glycol are preferred. The polyol and / or cross-linking agent and the polyisocyanate optionally undergo a polyaddition reaction in the presence of a catalyst to give a polyurethane. In this case, examples of the catalyst include those commonly used in the synthesis of polyurethane, and specific examples thereof include triethylenediamine, stannasoctoate, and the like.
The electrolyte used for forming the solid electrolyte using the reaction of the polyene / polythiol mixture and the urethanization reaction is the same as the electrolyte used for forming the solid electrolyte by the polymerization reaction of the unsaturated carboxylic acid ester. Things are used.

The non-aqueous electrolyte used for obtaining the solid electrolyte of the present invention is preferably added with an immersion aid for lowering the surface tension of the non-aqueous electrolyte and improving the permeation into the diaphragm or the active material. preferable. Examples of such immersion aids include silicone derivatives such as silicone oil and silicone-alkylene oxide adducts; polypropylene derivatives; perfluoroalkyl sulfonates; perfluoroalkyl quaternary ammonium iodides, and perfluoroalkyl polyoxyethylene ethanol. And fluorine derivatives such as fluorinated alkyl esters. Of these, preferred are silicone derivatives and fluorine derivatives.
This immersion aid is usually 0.1 to 10% by weight, preferably 0.5 to 5% by weight in the solid electrolyte. Outside this range, an economical immersion effect cannot be obtained. The formation of the solid electrolyte of the present invention is preferably performed under an inert gas atmosphere,
In this case, a solid electrolyte which is superior in terms of ionic conductivity and strength as compared with the case where it is manufactured in the atmosphere can be obtained.

The electrolyte salt is not particularly limited as long as it can be used for a non-aqueous battery.
R ₄ (R is a phenyl group or an alkyl group), LiPF ₆ , L
_{iSbF 6, LiAsF 6, LiBF 4} , LiCl
O ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ ,
LiC (CF ₃ SO ₂ ) ₃ , LiN (C ₂ F ₅ SO ₂ )
₂ , LiAlCl ₄ , and lithium tetrakis [3,5-bis (trifluoromethyl) phenyl] borate alone or in a mixture. Of these, LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ )
₂ is preferable in terms of ionic conductivity, safety, and the like.

As the non-aqueous solvent used in the present invention, carbonate solvents (propylene carbonate, ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, etc.), amide solvents (N-methylformamide, N-ethylformamide, etc.), lactone solvents (Γ-butyrolactone, γ-valerolactone, δ
Valerolactone, 3-methyl-1,3-oxazolidine-2-one, etc.), alcohol solvents (ethylene glycol, propylene glycol, glycerin, methyl cellosolve, 1,2-butanediol, 1,3-butanediol, 1, 4-butanediol, diglycerin, polyoxyalkylene glycol, cyclohexanediol, xylene glycol, etc.), ether solvent (methylal,
1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy-2-methoxyethane, alkoxypolyalkylene ether, etc., nitrile solvents (benzonitrile, acetonitrile, 3-methoxypropionitrile, etc.), phosphoric acids And phosphate ester solvents (normal phosphoric acid, metaphosphoric acid, pyrophosphoric acid, polyphosphoric acid, phosphorous acid, trimethyl phosphate, etc.), 2-imidazolidinones (1,3-dimethyl-2-imidazolidinone, etc.), pyrrolidones, sulfolane Solvents (sulfolane, tetramethylene sulfolane, etc.),
A furan solvent (tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethoxytetrahydrofuran), dioxolane, dioxane, dichloroethane alone or a mixture of two or more solvents can be used. Of these, preferred are carbonates, ethers and furan solvents.

In the polymer battery of the present invention, a solid polymer electrolyte comprising a thermoplastic polymer and a non-aqueous electrolyte is provided between a positive electrode and a negative electrode in which a solid polymer electrolyte comprising a crosslinked polymer matrix and an electrolyte salt is combined. By providing the layer, the impedance of the polymer battery can be significantly reduced. The solid polymer electrolyte layer comprising a thermoplastic polymer and a non-aqueous electrolyte, a solution obtained by heating and dissolving a thermoplastic polymer in a non-aqueous electrolyte, a polymer solid electrolyte comprising a cross-linked polymer matrix and an electrolyte salt. It can be easily provided by applying between the combined positive electrode and negative electrode and bonding the positive electrode and the negative electrode.

The thermoplastic polymer may be any polymer capable of holding a non-aqueous electrolyte, but may be a polyalkylene oxide such as polyethylene oxide or polypropylene oxide, polyacrylonitrile, polymethacrylate, polyvinylidene fluoride, or polyfluoroethylene. Copolymers of vinylidene fluoride and polyhexafluoropropylene are preferred because of their high non-aqueous electrolyte holding power and high ionic conductivity. Although one kind of thermoplastic polymer may be used,
A mixture or copolymer of two or more types can also be used.

As the non-aqueous electrolyte used for the polymer solid electrolyte composed of the thermoplastic polymer and the non-aqueous electrolyte, the above-mentioned non-aqueous electrolyte can be used. Considering evaporation of the solvent during dissolution, a non-aqueous solvent having a high boiling point is preferred. In particular, the boiling point is preferably 80 ° C. or higher,
100 ° C. or higher is more preferable. Specific examples include ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, and sulfolane.

In the polymer battery of the present invention, a separator can be used to prevent a short circuit. Examples of the separator include nonwoven fabrics and woven fabrics made of one or more materials arbitrarily selected from glass, polyester, polyethylene, polypropylene, polytetrafluoroethylene, and the like. Further, the polymer battery of the present invention can take various forms such as a flat type, a coin type, a square type, and a cylindrical type.

[0067]

【Example】

Example 1 1 part by weight of polyvinylidene fluoride, 20 parts by weight of LiCoO ₂ , 1 part by weight of acetylene black, and 1 part by weight of artificial graphite were respectively weighed, and N-methylpyrrolidone was added to form a paste on an aluminum foil. Coating and drying were performed to produce a positive electrode. Polyvinylidene fluoride 1
0 parts by weight and 90 parts by weight of natural graphite were weighed, N-methylpyrrolidone was added to form a paste, and the paste was applied onto a copper foil and dried to prepare a negative electrode.

A solution obtained by mixing ethylene carbonate and propylene carbonate at a volume ratio of 1: 1 was added at a concentration of 1.5M.
80 parts by weight of an electrolyte solution in which LiPF ₆ was dissolved, 14.5 parts by weight of furfuryl acrylate, 0.5 part by weight of trimethylolpropane triacrylate, and 0.1 part by weight of benzoin isopropyl ether were mixed to form a polymer. A solid electrolyte pre-solution (1) was prepared.

The polymer solid electrolyte pre-solution (1) was permeated into the positive electrode and the negative electrode, and irradiated with an electron beam to composite the electrode and the solid polymer electrolyte. 20 parts by weight of polyacrylonitrile was mixed with 80 parts by weight of an electrolyte obtained by dissolving 1.5 M concentration of LiPF ₆ in a solution in which ethylene carbonate and propylene carbonate were mixed at a volume ratio of 1: 1.
Heated to 0 ° C to obtain a uniform polymer solid electrolyte pre-solution (2)
Was prepared. The polymer solid electrolyte pre-solution (2) was applied on the positive electrode on which the polymer solid electrolyte was composited, and the negative electrode on which the polymer solid electrolyte was composited was bonded thereon. A polymer battery was manufactured using a laminated film having a laminated structure of polyethylene terephthalate / aluminum / polyethylene terephthalate / polyethylene as an exterior material.

Example 2 In the preparation of the negative electrode of Example 1, natural graphite 9 was used as the negative electrode active material.
A polymer battery was produced in the same manner as in Example 1 except that 60 parts by weight of natural graphite and 30 parts by weight of artificial graphite obtained by calcining fluid coke at 2300 ° C. were used instead of 0 parts by weight.

Example 3 A polymer battery was fabricated in the same manner as in Example 2 except that LiMn ₂ O ₄ was used instead of LiCoO ₂ as the positive electrode active material.

Example 4 In the polymer solid electrolyte pre-solution (1) of Example 2,
A polymer battery was produced in the same manner as in Example 2 except that ethoxyethylene glycol acrylate was used instead of furfuryl acrylate.

Example 5 In the polymer solid electrolyte pre-solution (2) of Example 4,
A polymer battery was produced in the same manner as in Example 4 except that a vinylidene fluoride-hexafluoropropylene copolymer was used instead of polyacrylonitrile.

Example 6 In place of the 1.5M concentration of LiPF ₆ in the polymer solid electrolyte pre-solutions (1) and (2) of Example 1, the concentration was 0.3M.
LiPF ₆ and 1M LiN (SO ₂ C ₂ F ₅ )
_A polymer battery was produced in the same manner as in Example 1 except that _No.2 was used.

Example 7 A polymer electrolyte was produced in the same manner as in Example 1 except that polyethylene glycol acrylate was used instead of furfuryl acrylate in the pre-solution (1) of the solid polymer electrolyte solution in Example 1. The viscosity of the polymer solid electrolyte pre-solution (1) was 160 cP in Example 7, while the viscosity of the polymer solid electrolyte pre-solution in Example 1 was 60 cP.

Comparative Example 1 A polymer battery was manufactured in the same manner as in Example 1 except that the solid polymer electrolyte was composited and the positive electrode and the negative electrode were directly attached to each other.

The battery performances of the polymer batteries prepared in Examples 1 to 7 and Comparative Example 1 were measured. In this case, 400m
A [(2/3) C equivalent], constant-current constant-voltage charging up to 4.2 V for 2.5 hours, and 300 mA [(1
/ 2) C], the discharge capacity at the 5th, 100th, and 300th cycles was measured. The results are shown in [Table 1].

[0078]

[Table 1]

[0079]

As apparent from the above description, the following effects can be obtained according to the present invention. (1) In the invention according to claim 1, in a polymer battery using a positive electrode and / or a negative electrode in which a solid polymer electrolyte comprising a crosslinked polymer matrix and an electrolyte salt is compounded,
By providing a polymer solid electrolyte layer consisting of a thermoplastic polymer and a non-aqueous electrolyte between the positive electrode and the negative electrode, the impedance of the polymer battery can be reduced, thus enabling rapid charging and high load discharge. Become.

(2) According to the second aspect of the present invention, the positive electrode and / or the negative electrode in which the solid polymer electrolyte composed of the crosslinked polymer matrix and the electrolyte salt contains a non-aqueous solvent, Since the ionic conductivity of the polymer battery is improved, it is possible to provide a polymer battery capable of quick charge and high load discharge.

(3) According to the third aspect of the present invention, the composite operation can be performed in a state where the interface between the electrode and the solid polymer electrolyte is in a good state, and the electrode reaction proceeds smoothly. , The impedance of the battery becomes low, and rapid charging and high-load discharging become possible.

(4) According to the fourth aspect of the present invention, since the electrode and the solid polymer electrolyte can be combined to the inside of the electrode, the impedance of the polymer battery is reduced, and rapid charging and high-load discharging are possible. .

(5) According to the fifth aspect of the present invention, since the ionic conductivity of the solid polymer electrolyte is high, the impedance of the polymer battery is reduced, and rapid charging and high-load discharging can be performed.

(6) According to the sixth aspect of the present invention, since the composite of the electrode and the solid polymer electrolyte can be performed quickly and without deterioration, the impedance of the polymer battery is reduced, and the charge of the polymer battery is increased. Load discharge becomes possible.

(7) In the invention of claim 7, since the ionic conductivity of the polymer solid electrolyte layer composed of the thermoplastic polymer and the non-aqueous electrolyte is high, the impedance of the polymer battery is reduced, so that rapid charging and high load are performed. Discharge becomes possible.

Claims (7)

[Claims] 1. A polymer battery using, as an electrode, a positive electrode and / or a negative electrode in which a solid polymer electrolyte comprising a crosslinked polymer matrix and an electrolyte salt is compounded.
A polymer battery, comprising a polymer solid electrolyte layer comprising a thermoplastic polymer and a non-aqueous electrolyte between a positive electrode and a negative electrode. 2. The polymer battery according to claim 1, wherein the positive electrode and / or the negative electrode in which the solid polymer electrolyte composed of the crosslinked polymer matrix and the electrolyte salt is combined contain a non-aqueous solvent. . 3. A positive electrode and / or a negative electrode in which a solid polymer electrolyte comprising a crosslinked polymer matrix and an electrolyte salt is composited, an electrode obtained by molding at least an electrode active material with a binder and at least a polymerizable monomer and an electrolyte salt. 3. The polymer battery according to claim 1, wherein the polymer battery is prepared by impregnating a solution with the polymerizable monomer and then reacting the polymerizable monomer. 4. 4. The polymer battery according to claim 3, wherein the viscosity of the solution comprising the polymerizable monomer and the electrolyte salt is 100 cP or less. 5. The polymerizable monomer according to claim 3, wherein the monomer comprises a monomer represented by the following chemical formula 1 and / or a monomer represented by the following chemical formula 2. 5. The polymer battery according to 4. Embedded image (In the formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrocarbon group or a group containing a heterocyclic ring, and n is an integer of 1 or more.) (Wherein, R ₃ represents a hydrogen atom or a methyl group, and R ₄ represents a group containing a heterocyclic ring) 6. The polymer battery according to claim 3, wherein the reaction of the polymerizable monomer is a polymerization reaction caused by irradiation with energy rays. 7. The method according to claim 1, wherein the thermoplastic polymer is polyacrylonitrile, polymethacrylate, polyvinylidene fluoride or polyalkylene oxide, or a copolymer of polyvinylidene fluoride and polyhexafluoropropylene. 7. The polymer battery according to any one of items 1 to 6.