JP2000149660A - Solid polyelectrolyte and electrochemical device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture an electrolyte without using a plasticizer, to enhance ion conductivity and to realize lightening by containing an olefin maleimide copolymer of N-alkyl maleimide and olefin, and an electrolytic solution. SOLUTION: An olefin-maleimide copolymer having a structural unit expressed by formula I and a structural unit expressed by formula II is used for this solid electrolyte. In formula I, R1, R2 and R3 are independently a 1-8C alkyl group or a hydrogen atom. In formula II, R4 represents a 1-18C alkyl group, a 3-12C cycloalkyl group or a hydrogen atom. Preferably, the structural unit expressed by formula I is 70-2 mol% of the olefin-maleimide copolymer, and the structural unit expressed by formula II is 30-98 mol% of the copolymer. The weight average molecular weight of the copolymer is preferably 1×103 to 1×107 when calculated in terms of polystyrene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer solid electrolyte suitably used for electrochemical devices such as a battery, a capacitor, a display, and a sensor, and an electrochemical device using the polymer solid electrolyte.

[0002]

2. Description of the Related Art In a conventional electrochemical device, an aqueous solution or a non-aqueous solution (electrolytic solution) using an organic solvent has been often used as an electrolyte, but there are problems in necessity of sealing, securing of safety, and the like. Therefore, the necessity of an ion conductive polymer solid electrolyte having flexibility, elasticity, light weight, thin film forming property, transparency, and the like is increasing. In particular, electrochemical devices such as batteries and capacitors, which are important components of electronic products, use ion-conductive polymers as electrolytes due to demands for weight reduction, compactness, freedom of shape, and large area. Is actively being developed.

As an example using an ion conductive polymer, a type (uniform) composed of a polymer such as polyethylene oxide (PEO) or a polyether such as polypropylene oxide (PPO) or a derivative thereof and an electrolyte salt containing Li or the like is used. Type, dry type), a type in which a plasticizer is mixed with a polymer to improve electrochemical characteristics (hybrid type / gel type), and a type in which a composite salt of an electrolyte is held by a polymer (PIS: Polymer in Salt).

At present, in the development of polymer batteries using solid polymer electrolytes (SPEs), gel-type SPEs are mainly the focus of research due to their high ionic conductivity, and PEO-based, PAN (polyacrylonitrile) System, P
It is said that polymers such as VDF (polyvinylidene fluoride) have high utility.

[0005] Among them, PVDF has long been studied as an SPE because it has excellent heat resistance and chemical resistance and has sufficient mechanical strength. However, since the crystalline portion of the polymer is not considered to contribute to ion conduction, PVDF having high crystallinity is disadvantageous as an SPE as it is, and therefore, propylene hexafluoride ( HFP), trifluoroethylene (Tr
P (VDF-HFP) using FE) or tetrafluoroethylene (TFE): U.S. Pat. No. 3,985,574
Specification, P (VDF-TFE), P (VDF-TrF
E): Copolymers such as JP-A-58-75779 have been proposed.

For example, US Pat. No. 5,296,318 discloses a copolymer of vinylidene fluoride (VDF) and 8 to 25% by weight of propylene hexafluoride (HFP) [P (VDF
-HFP)], the solution in which the lithium salt is dissolved is 20 to 7
A gel electrolyte containing 0 wt% is disclosed. The conductivity of this gel electrolyte reaches 10 ⁻³ S · cm ⁻¹ . Such a VDF-HFP copolymer can contain a large amount of a solvent because HFP lowers the crystallinity of PVDF, and also suppresses the precipitation of lithium salt crystals, and further increases the strength. Certain gel electrolytes can be made.

As a method for producing a gel-type SPE, a polymer is dissolved in a solvent, an electrolytic solution or the like is mixed therewith, plasticized, and then applied to a substrate by various methods to evaporate the solvent. Generally, a method of obtaining an SPE film by performing the method is as follows. Also,
There has also been proposed a method in which a polymer is directly dissolved in an electrolytic solution to produce an SPE film by coating or extrusion.
However, since organic electrolytes used for electrochemical devices generally dislike water, when industrially producing SPE using these methods, it is necessary to maintain all processes in a dry atmosphere, which is expensive. Capital investment and maintenance costs are required, and inventory management in the process is not easy.

In US Pat. No. 5,418,091, a plasticizer is added to a polymer solution, applied to a substrate, and then the solvent is volatilized to produce a film from which the plasticizer is extracted. SPE that impregnates the formed voids with electrolyte
Is described. In this method, the electrolytic solution is used only in the impregnating step and the encapsulating step, and the previous step can be performed in a normal environment, so that the capital investment and maintenance cost can be greatly reduced. Further, since the SPE can be stocked in a film state after coating / drying or after extraction of the plasticizer, inventory management becomes easy. However, in this method, as an extraction step, it is necessary to immerse the plasticizer-containing polymer film in a large amount of a solvent a plurality of times, and this step has the
In addition to greatly reducing mass productivity, a large amount of waste solvent must be treated, which is problematic in terms of the environment. Extraction can also be achieved by heating the plasticizer-containing polymer film under reduced pressure. However, in this case, productivity and mass productivity are greatly affected, and introduction of equipment and an increase in cost are inevitable. Furthermore, recently, the effect of the plasticizer on the environment has been regarded as a problem.

[0009] Therefore, in order to manufacture the SPE industrially simply and safely, it is necessary to sufficiently impregnate the polymer constituting the SPE with the electrolyte later without using a plasticizer. It is preferable that the molecules have a swelling property with respect to the electrolytic solution.

In view of these problems, the present inventors have:
Japanese Patent Application Nos. 9-95030 and 10-18693
No. 8 (Japanese Patent Application No. 9-245821) discloses an SPE having a high electrolyte swelling property and an electrochemical device using the same, and Japanese Patent Application No. 10-256059 (Japanese Patent Application No.
No. 368028) proposes a separator using SPE. However, development of a new SPE is required to meet a wider range of applications. In particular,
2. Description of the Related Art With the trend of miniaturization and weight reduction of electronic devices, reduction in weight of electrochemical devices such as batteries and capacitors is demanded from many fields. The above-mentioned PVDF-based polymer from which high ionic conductivity can be obtained has a relatively high density and is insufficient in terms of weight reduction of a solid polymer electrolyte.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer solid electrolyte which can be easily produced without using a plasticizer, has a high ionic conductivity, and can be reduced in weight.
An object of the present invention is to provide an electrochemical device having high productivity and mass productivity and excellent characteristics by using the same.

[0012]

This and other objects are achieved by the present invention which is defined below. (1) A polymer solid electrolyte containing an olefin / maleimide copolymer of an N-alkylmaleimide and an olefin, and an electrolytic solution. (2) The polymer solid electrolyte according to the above (1), wherein the olefin / maleimide copolymer has a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2): .

[0013]

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[0014]

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(In the formula (1), R ₁ , R ₂ and R ₃
Represents an alkyl group having 1 to 8 carbon atoms or a hydrogen atom, respectively, and in the formula (2), R ₄ represents 1 to 18 carbon atoms.
Represents a cycloalkyl group having 3 to 12 carbon atoms or a hydrogen atom. (3) The structural unit represented by the formula (1) is 70 to 2 mol% of the olefin / maleimide copolymer,
The structural unit represented by the formula (2) is the olefin.
The polymer solid electrolyte according to the above (2), which is 30 to 98 mol% of the maleimide copolymer. (4) The polymer solid electrolyte according to (3), wherein the olefin / maleimide copolymer has a structural unit represented by the following general formula (I).

[0016]

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(In the general formula (I), R ₁ , R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms or a hydrogen atom; R ₄ represents an alkyl group having 1 to 18 carbon atoms;
Represents a cycloalkyl group having 3 to 12 carbon atoms or a hydrogen atom. (5) wherein R ₁ is hydrogen, R ₂ and R ₃
Is a methyl group, and R ₄ is a methyl group. (2) to (4). (6) The weight average molecular weight of the olefin / maleimide copolymer is from 1 × 10 ³ to 1 × 10 ^{7 in} terms of polystyrene.
The solid polymer electrolyte according to any one of the above (1) to (5). (7) An electrochemical device using the solid polymer electrolyte according to any one of (1) to (6). (8) The electrochemical device according to (7), which is a lithium secondary battery or an electric double layer capacitor.

[0018]

The solid polymer electrolyte (SPE) of the present invention contains a copolymer of olefin and N-alkylmaleimide (olefin / maleimide copolymer) and an electrolyte.
The olefin / maleimide copolymer used in the present invention has a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2), and has a weight average molecular weight of: It is preferably 1 × 10 ³ to 1 × 10 ⁷ in terms of polystyrene.

[0019]

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[0020]

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In the formula (1), R ₁ , R ₂ and R
₃ represents an alkyl group having 1 to 8 carbon atoms or a hydrogen atom, and in the formula (2), R ₄ represents 1 to 1 carbon atoms.
8 represents an alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or a hydrogen atom.

The olefin / maleimide copolymer is preferably an alternating copolymer, that is, an olefin / maleimide copolymer represented by the following general formula (I).

[0023]

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In the general formula (I), R ₁ , R ₂ and R
₃ represents an alkyl group having 1 to 8 carbon atoms or a hydrogen atom, and R ₄ represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a hydrogen atom.

In the olefin / maleimide copolymer described above, the maleimide moiety has polarity, so that it has a high affinity for an electrolytic solution which is a polar solvent. Therefore, by immersing the polymer film in the electrolytic solution, the polymer swells and an SPE gel having high ionic conductivity can be easily obtained.
The degree of swelling of the polymer used in the present invention by the electrolytic solution is about 2 to 5, which is equal to or higher than that of the conventional one. As mentioned above,
The conventional polymer solid electrolyte having high productivity described in U.S. Pat. No. 5,418,091 and the like requires a plasticizing step. There is no need to convert. Therefore, productivity and mass productivity are high. It is also preferable in terms of the environment, which has recently become a problem.

The SPE of the present invention also has a high ionic conductivity, and an ionic conductivity equal to or higher than that of a conventional plasticized SPE can be obtained.

The olefin / maleimide copolymer used in the present invention has a density of 1.1 to 1.2 g / cm ³ . A conventionally used fluororesin (PVDF-based polymer) contains a halogen atom such as fluorine in its structure, and has a high density of about 1.8 g / cm ³ . Since the polymer used in the present invention has a low density, the weight of the SPE can be reduced.

Further, the olefin / maleimide copolymer has a glass transition point (Tg) as high as about 105 to 230 ° C. and a Tg lower than that, PEO, PVDF (Tg: both below freezing point), and PMMA (Tg: 100 ° C.). The SPE of the present invention is superior in heat resistance as compared with the conventional SPE using (degree).

It also has excellent chemical resistance, and at normal temperature, tetrahydrofuran (THF), dimethylformamide (D
It is soluble only in limited solvents such as MF) and N-methylpyrrolidone (NMP).

The olefin / maleimide copolymer has a high degree of swelling with respect to the electrolytic solution without using a plasticizer because the maleimide portion has polarity and has high affinity with the electrolytic solution. It has no electrochemically unstable functional groups such as -OH groups. Therefore, an SPE having a wide potential window and stable over a wide range of voltages can be obtained.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION <Polymer> The polymer solid electrolyte of the present invention is a polymer obtained by copolymerizing an olefin and an N-alkylmaleimide, that is, a structural unit represented by the above formula (1), An olefin / maleimide copolymer having the structural unit represented by the above formula (2) is used.

In the formula (1), R ₁ , R ₂ and R
₃ represents an alkyl group having 1 to 8 carbon atoms or a hydrogen atom, respectively. R ₁ , R ₂ and R ₃ may be the same or different from each other.

The alkyl group represented by R ₁ , R ₂ and R ₃ may be linear or branched, preferably has 1 to 3 carbon atoms, and particularly preferably is a methyl group.

In the structural unit represented by the formula (1), R ₁ is particularly preferably hydrogen. Further, R ₂ and R ₃ are preferably an alkyl group, particularly a methyl group. Above all, R
It is preferred that ₁ is hydrogen and R ₂ and R ₃ are methyl groups from the viewpoint of heat resistance and mechanical strength.

When the structural unit represented by the formula (1) has a linear alkyl group such as 2-methyl-1-heptene,
Although flexibility is excellent, heat resistance tends to decrease. In the case of having a bulky alkyl group such as isooctene or a trisubstituted olefin such as 2-methyl-2-butene, the heat resistance is improved, but the mechanical strength tends to be reduced.

In the formula (2), R ₄ (N-alkyl substituent) is an alkyl group having 1 to 18 carbon atoms,
2 represents a cycloalkyl group or a hydrogen atom.

The alkyl group represented by R ₄ may be linear or branched, and preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably methyl. Groups are preferred from the viewpoint of heat resistance and mechanical properties.
When R ₄ has a long chain, flexibility is excellent, but heat resistance tends to decrease.

The cycloalkyl group represented by R ₄ preferably has 3 to 6 carbon atoms, particularly preferably a cyclohexyl group.

As R ₄ , an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms is preferable in terms of heat resistance. Further, a methyl group, an ethyl group, an isopropyl group or a cyclohexyl group, particularly a methyl group is preferable. Preferably, there is. When R ₄ is a cycloalkyl group, the heat resistance is improved as compared with the case where R ₄ is an alkyl group, but it tends to be brittle.

By changing R ₁ , R ₂ , R ₃ and R ₄ , the affinity with the electrolytic solution changes. In order to reduce the weight of the solid polymer electrolyte, it is preferable that R ₁ , R ₂ , R ₃ and R ₄ have a small number of carbon atoms.

The olefin which provides the structural component represented by the above formula (1) includes isobutene, ethylene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-methyl-1-hexene, -Methyl-1-heptene, 1-
Methyl-1-heptene, 1-isooctene, 2-methyl-1-octene, 2-ethyl-1-butene, 2-ethyl-1-pentene, 2-methyl-2-butene, 2-methyl-2-pentene, Examples thereof include 2-methyl-2-hexene, and it is preferable to use isobutene.

Examples of the N-alkylmaleimide which provides the structural component represented by the above formula (2) include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, Ni-propylmaleimide, and N-alkylmaleimide. n-butylmaleimide, Ni-butylmaleimide, Ns-butylmaleimide, Nt-butylmaleimide, Nn-pentylmaleimide, Nn-hexylmaleimide, Nn
Heptylmaleimide, Nn-octylmaleimide,
N-lauryl maleimide, N-stearyl maleimide,
N-cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, N-cycloheptylmaleimide, N
-Cyclooctylmaleimide and the like, and N-methylmaleimide, N-ethylmaleimide, Ni-propylmaleimide, and N-cyclohexylmaleimide are preferably used.

In the olefin / maleimide copolymer used in the present invention, the structural unit represented by the above formula (1) is 70 to 2 mol% of the olefin / maleimide copolymer, particularly 50%.
It is preferable that the content of the structural unit represented by the formula (2) is 30 to 98 mol%, particularly 50 to 80 mol% of the olefin / maleimide copolymer. If the amount of the maleimide component represented by the formula (2) is more than this, the polymer tends to become brittle, and if it is less than this, the heat resistance of the polymer tends to decrease.
In particular, the structural unit represented by the formula (1) is preferably 50 mol%, and the structural unit represented by the formula (2) is preferably 50 mol%, and an alternating copolymer is preferable. The content of these components can be determined as appropriate by adjusting the amount of the monomer used in the polymerization.

The olefin component represented by the formula (1) may be one kind or two or more kinds. The maleimide component represented by the formula (2) may be one kind or two kinds. The above may be used.

The olefin / maleimide copolymer may be a random copolymer or a block copolymer, but is preferably an alternating copolymer, that is, an olefin / maleimide copolymer represented by the above general formula (I). Polymers are preferred.

In the general formula (I), R ₁ , R ₂ and R
₃ has the same meaning as R ₁ , R ₂ and R ₃ in the formula (1), and preferred examples are also the same. In addition, the general formula (I)
In the formula, R ₄ has the same meaning as R ₄ in formula (2), and preferred examples are also the same.

The weight average molecular weight of the olefin / maleimide copolymer used is 1 × 10 ³ to 1 in terms of polystyrene.
× 10 ⁷ , particularly preferably 1 × 10 ⁴ to 1 × 10 ⁶ . If the molecular weight is higher than this, the moldability tends to deteriorate, and if it is lower than this, the polymer becomes brittle and the solvent resistance tends to decrease. General formula (I)
The degree of polymerization of the olefin / maleimide alternating copolymer represented by is usually up to about 1500.

At the terminal of the copolymer represented by the general formula (I), usually, either an olefin monomer or a maleimide monomer remains.

Further, the olefin / maleimide copolymer used in the present invention may be obtained by copolymerizing another vinyl monomer. Examples of the other vinyl monomer include styrene and α-
Methylstyrene, vinyltoluene, 1,3-butadiene, isoprene and halogen-substituted derivatives thereof, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, methacrylic acid Phenyl, methacrylates such as benzyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, butyl acrylate, hexyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, phenyl acrylate, acrylic acid Acrylates such as benzyl,
Vinyl esters such as vinyl acetate and vinyl benzoate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether and butyl vinyl ether; vinyl chloride, vinylidene chloride, maleic anhydride, N-phenylmaleimide, N-carboxyphenylmaleimide, acrylonitrile , Ethylene, propylene, 1-butene, 2-butene, 1-hexane and the like. These vinyl monomers are preferably at most 15 mol%, more preferably at most 10 mol%, based on the maleimides.

The following are specific examples of the olefin / maleimide copolymer, but the present invention is not limited to these. In addition, Chemical Formula 10 is represented using the expressions (1) and (2).

[0051]

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Such an olefin / maleimide copolymer is obtained by a radical copolymerization reaction between an N-alkyl-substituted maleimide and an olefin, and is obtained by a known polymerization method, for example, a bulk polymerization method, a solution polymerization method, a suspension polymerization method. And the emulsion polymerization method. In particular, it is possible to carry out precipitation polymerization using a polymerization solvent in which the raw material N-alkylmaleimide and the olefin dissolve but the produced polymer does not dissolve, thereby simplifying the production process. This is particularly preferred in terms of
Specifically, JP-A-4-31407, JP-A-4-3140
No. 8, No. 4-50210, No. 4-50211, No. 4
No.-50212, No.4-50213, No.4-5021
No. 4, 4-53810, 5-117453, 5-117461, 5-117484, 5-1
No. 40380, No. 5-59131, No. 5-19460
No. 9, 5-209004, 6-220106 and the like, or can be synthesized in accordance therewith.

Alternatively, the copolymer can be synthesized by polymerizing an olefin and maleic acid and then imidizing the copolymer with an alkylamine or the like corresponding to R ₄ (N-alkyl substituent). Such a post-imidization reaction, for example, a maleic anhydride-olefin copolymer in a molten state, or methanol, ethanol, propanol, butanol alcohol solvent or benzene, toluene,
Dissolve or disperse in an aromatic solvent such as xylene or the like, and react with a primary amine such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, s-butylamine, t-butylamine, cyclohexylamine at 100 to 350 ° C. The reaction is carried out at a temperature. Further, a compound which easily generates an amine by heat treatment of ammonia, dimethyl urea, diethyl urea, or the like can also be used. Specifically, Japanese Patent Application Laid-Open No. 6-24 / 1994
No. 8018, No. 7-138318, No. 7-13831
The compound may be synthesized according to or according to each gazette such as No. 9 or No. 8-27221.

The identification of such a polymer is carried out by elemental analysis, infrared absorption spectrum (IR), nuclear magnetic resonance spectrum (N
MR) or the like. The weight average molecular weight (Mw) can be determined by a light scattering method, gel permeation chromatography (GPC), or the like.

The olefin / maleimide copolymer used in the present invention may be further modified with a reactive group. Examples of such a reactive group include carboxylic acids and derivatives thereof, metal salts, acid anhydrides, epoxy groups, amino groups, hydroxyl groups, thiol groups, alkoxysilyl groups, and isocyanate groups. In this case, the content of the reactive group is 25 mol% or less, especially 0.01 to
It is preferably 20 mol%, more preferably 0.02 to 10 mol%, even more preferably 0.02 to 5 mol%. When the reactive group exceeds 25 mol%, the thermal stability and mechanical strength of the polymer tend to decrease.

Such modified polymers include, for example, maleic anhydride, citraconic anhydride, itaconic anhydride, (meth) acrylic acid, itaconic acid, fumaric acid, glycidyl (meth) acrylate, aminomethyl (meth) acrylate And aminoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, aminostyrene, allylamine and the like. Further, an initiator having a reactive group such as 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-cyanopropanol), 2,2′-azobisisobutylamide, or It is also possible to introduce a reactive group into the polymer terminal by using a chain transfer agent having a reactive group such as mercaptoacetic acid and mercaptopropionic acid. In addition, after polymerizing an olefin and maleic anhydride, when obtaining an olefin / maleimide copolymer by imidizing the copolymer, it is possible to leave an acid anhydride unit by adjusting the amount of imidization. it can.

In the present invention, in addition to the olefin / maleimide copolymer, an olefin resin, an acrylic resin, a polystyrene, a vinyl chloride resin, a polyphenylene ether, a polyacetal, a polyamide, a polyester,
Polyphenylene sulfide, polyimide, polycarbonate, polysulfone, fluorine-based resin, styrene / maleimide copolymer, diene-based, olefin-based, acrylic, urethane-based, fluorine-based, silicone-based elastomer, and random polymers and blocks thereof Polymers, graft polymers, etc., and polyamine compounds such as diamines or polyamines such as diaminodiphenyl ether; diepoxy compounds such as diglycidyl phthalate, diglycidyl ether phthalate, resorcin diglycidyl ether; , Preferably 5 to 30% by weight. By blending or melt-kneading polymers having different structures, they can be blended to improve moldability and flexibility.

Examples of the olefin resin include polyethylene, polypropylene, poly-4-methyl-1-pentene and modified products thereof.

Here, polyethylene is a resin mainly composed of ethylene units.
It refers to a polymer having a mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more, particularly preferably 85 mol% or more, and further preferably 90 mol% or more. Polyethylene includes other copolymerizable unsaturated monomers such as α-olefins such as propylene, 1-butene and 1-hexene, vinyl ethers, vinyl esters such as vinyl acetate and vinyl propionate, ( A (meth) acrylic acid ester, acrylonitrile, or the like may be copolymerized or graft-polymerized.

Polypropylene is a resin mainly composed of propylene units.
1% or more, and refers to other copolymerizable unsaturated monomers such as α-olefins such as ethylene, 1-butene and 1-hexene, vinyl ethers, vinyl acetate, vinyl propionate and the like. May be copolymerized or graft-polymerized with vinyl esters, (meth) acrylates, acrylonitrile, and the like.

Poly-4-methyl-1-pentene is defined as 4-
A resin mainly containing methyl-1-pentene unit, and other copolymerizable unsaturated monomers such as α-olefins such as ethylene, propylene, 1-butene, and 1-hexene, vinyl ethers, and acetic acid. Vinyl esters such as vinyl and vinyl propionate, (meth) acrylates, and acrylonitrile may be copolymerized or graft-polymerized.

These olefin resins may be modified with various reactive groups. In this case, the reactive groups include acid anhydrides, carboxylic acids and derivatives thereof, hydroxyl groups, thiol groups, and amino groups. , An epoxy group, an alkoxysilyl group, an isocyanate group and the like. The amount of modification by these reactive groups is 25 mol% or less,
In particular, it is preferably at most 20 mol%, more preferably 0.01 to 15 mol%, even more preferably 0.02 to 5 mol%.
When the reactive group exceeds 25 mol%, the thermal stability and mechanical strength of the polymer tend to decrease.

These modifications include, for example, maleic anhydride, citraconic anhydride, itaconic anhydride, (meth) acrylic acid, hydroxyethyl (meth) acrylate, aminoethyl (meth) acrylate, glycidyl (meth) acrylate Can be produced by copolymerization or graft polymerization.

In the case of polypropylene, a modified polypropylene grafted with maleic anhydride or (meth) acrylic acid is preferred.

Examples of the polyamide resin include polyamides obtained by ring-opening polymerization of lactams such as ε-caprolactam and ω-dodecalactam; 6-aminocaproic acid, 11
Polyamides obtained from amino acids such as -aminoundecanoic acid and 12-aminododecanoic acid; ethylenediamine, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,
2,4-trimethylhexamethylenediamine, 1,3-
Or 1,4-bis (aminomethyl) cyclohexane,
Aliphatics such as bis (4,4′-aminocyclohexyl) methane, metaxylenediamine, paraxylenediamine,
Alicyclic and aromatic diamines, adipic acid, speric acid,
Sebacic acid, dodecane diacid, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, aliphatics such as terephthalic acid,
Examples include polyamides obtained from alicyclic and aromatic dicarboxylic acids, copolymers thereof, and mixtures thereof. Of these, nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, and nylon 46 are preferred. Usually, the molecular weight of the polyamide is preferably 10,000 or more.

Examples of the polyester resin include polybutylene terephthalate, polyethylene terephthalate, polyarylate, and liquid crystalline polyester.

The elastomer is not particularly limited as long as it is a polymer having a glass transition temperature of 10 ° C. or lower, and is a diene elastomer and its hydrogenated product, an olefin elastomer and its hydrogenated product, an acrylic elastomer, a urethane elastomer. And fluorine-based elastomers, silicone-based elastomers, amide-based elastomers, ester-based elastomers, and the like, and olefin-based elastomers and acrylic-based elastomers are preferred in view of weather resistance and mechanical properties.

Examples of the olefin elastomer include butyl rubber and ethylene elastomer. Here, butyl rubber is an elastomer mainly composed of polyisobutylene, and ethylene-based elastomer is polyethylene and its copolymer, and the ethylene unit is preferably at least 50 mol%, more preferably at least 75 mol% of the whole elastomer. Is referred to as a polymer. Other unsaturated monomers copolymerizable with ethylene include, for example, α-olefins such as propylene, 1-butene and 1-hexene, vinyl ethers, vinyl esters such as vinyl acetate and vinyl propionate, and ( Examples thereof include (meth) acrylic esters, acrylonitrile, and the like, which may be copolymerized or graft-polymerized.

The acrylic elastomer is an elastomer mainly composed of an acrylic ester such as methyl ester, ethyl ester or butyl ester of acrylic acid. Other copolymerizable components include aromatic monomers such as styrene. Methacrylic acid esters, vinyl acetate and the like can be mentioned.

These elastomers are preferably modified with various reactive groups. Examples of the reactive groups include acid anhydrides, carboxylic acids and derivatives thereof, hydroxyl groups, thiol groups, amino groups, Examples include an epoxy group, an alkoxysilyl group, and an isocyanate group. The amount of modification by these reactive groups is 30 mol% or less, more preferably 0.001 to 25 mol%, and particularly 0.01 to 25 mol%.
It is preferably 20 mol%, more preferably 0.02 to 15 mol%, even more preferably 0.05 to 5 mol%.

These modifications include, for example, maleic anhydride, citraconic anhydride, itaconic anhydride, (meth) acrylic acid, itaconic acid, fumaric acid, hydroxyethyl (meth) acrylate, aminoethyl (meth) acrylate,
It can be produced by copolymerization or graft polymerization using glycidyl (meth) acrylate, 3- (triethoxysilyl) propyl methacrylate, allylamine, or the like.

These elastomers are more specifically exemplified by polybutadienes, styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, acrylonitrile / styrene / butadiene copolymers, methyl methacrylate / styrene / butadiene copolymers, Diene-based elastomers such as isoprene and polychloroprene and their acid anhydride-modified, epoxy- or hydroxy-modified products, hydrogenated products of the above-mentioned diene-based elastomers and their acid anhydride-modified, epoxy-modified or carboxy-modified products Olefin elastomers such as ethylene / propylene (ethylidene norbornene) rubber, butyl rubber, ethylene / vinyl acetate rubber, ethylene / methyl acrylate, and modified acid anhydrides, epoxy modified, carboxy Or hydroxy-modified, glycidyl methacrylate-modified, acrylic rubber mainly composed of ethyl acrylate and its anhydride-modified, epoxy-modified, amino-modified, polysiloxane-epoxy-modified, hydroxy-modified, amino-group Modified product, ethylene / acrylic acid copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / maleic anhydride copolymer, ethylene / vinyl acetate / anhydride Maleic acid copolymer, ethyl acrylate / glycidyl methacrylate copolymer, ethyl acrylate /
Butyl acrylate / maleic anhydride copolymer;

When a modified diene elastomer is used, the low temperature impact resistance is improved, and when a modified olefin elastomer or acrylic elastomer is used, weather resistance and impact resistance are improved.

It is also possible to carry out the polymerization of the olefin and the maleimide in the presence of a rubbery polymer and use it as a graft polymer. Here, the rubbery copolymer is
Diene rubbers such as polybutadiene, polyisoprene, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, olefin rubber, acrylic rubber,
Silicone rubber and the like can be mentioned.

The olefin / maleimide copolymer used in the present invention may contain a hindered phenol,
A heat stabilizer such as an organic phosphate, a benzotriazole-based UV absorber, a hindered amine-based UV stabilizer, various lubricants, and various fillers may be added.

The olefin / maleimide copolymer used in the present invention has a high affinity for an electrolyte, which is a polar solvent, since the maleimide moiety has polarity. The degree of swelling of the polymer used in the present invention with the electrolytic solution is about 2 to 5, preferably 2 to 4. The degree of swelling is defined as the weight ratio before and after the polymer material is impregnated with the electrolyte and swelled. That is, a swelling degree of 2 means that the weight of the polymer was doubled by the impregnation of the electrolyte, and the weight ratio of the electrolyte / polymer material after swelling was 1
/ 1. Although the SPE of the present invention has a high degree of swelling, sufficient strength and liquid retention can be obtained. This copolymer can obtain a sufficient degree of swelling without plasticization, and does not require the use of an essential plasticizer in conventional high-productivity gel electrolytes, as long as productivity and mass productivity only improve. It is preferable because the influence on the environment is reduced.

Since the olefin / maleimide copolymer has a water absorption of about 1% by weight, it is dried at 100 ° C. or less at normal pressure or under vacuum when used.

At room temperature, the copolymer does not dissolve in an electrolyte such as ethylene carbonate or diethyl carbonate, and the polymer solid electrolyte of such a copolymer is used for lithium secondary batteries, electric double layer capacitors, etc. When used for an electrochemical device, the storage characteristics are good.

<Electrolyte Salt> The electrolyte generally comprises an electrolyte salt and a solvent. Considering application to lithium batteries, the electrolyte salt needs to contain Li, and specifically, LiBF
_{4, LiPF 6, LiAsF 6,} LiSO 3 CF 3, L
Lithium salts such as iClO ₄ and LiN (SO ₂ CF ₃ ) ₂ can be used. When used for an electric double layer capacitor, a quaternary ammonium salt such as tetraethylammonium perchlorate and tetraethylammonium borofluoride can be used in addition to the alkali metal salt containing the Li salt. In addition, an electrolyte salt compatible with a solvent described below may be appropriately selected depending on an applied electrochemical device. Such an electrolyte salt may be used alone, or a plurality of salts may be mixed at a predetermined ratio.

<Solvent> The solvent of the electrolytic solution is not particularly limited as long as it has good compatibility with the above-mentioned copolymer and electrolyte salt. However, in a lithium battery or the like, decomposition does not occur even at a high operating voltage. Polar organic solvents, for example, ethylene carbonate (abbreviated as EC), propylene carbonate (abbreviated as PC), butylene carbonate, dimethyl carbonate (abbreviated as DMC), carbonates such as diethyl carbonate and ethyl methyl carbonate, tetrahydrofuran (THF), 2-methyltetrahydrofuran Cyclic ethers such as 1,3-dioxolane and 4-methyldioxolane; lactones such as γ-butyrolactone; and sulfolane. 3-Methylsulfolane, dimethoxyethane, diethoxyethane, ethoxymethoxyethane, ethyldiglyme and the like may be used. In addition, a known solvent may be appropriately selected according to a device to be applied.

When it is considered that the electrolyte is composed of the solvent and the electrolyte salt, the concentration of the electrolyte salt is preferably 0.3 to 5 mol.
l / l. Usually, it exhibits the highest ionic conductivity at around 1 mol / l. When the composition of the SPE is represented by a copolymer / electrolyte solution, the ratio of the electrolyte solution is preferably 40 to 90% by weight in view of the strength of the membrane and the ionic conductivity.

<Preparation of SPE> Next, a specific method for producing a solid polymer electrolyte will be described.

In the present invention, since the swelling degree of the olefin / maleimide copolymer is high, the SPE can be easily obtained by impregnating the polymer film formed into a sheet in advance with the electrolytic solution. Moreover, the polymer need not be plasticized. Traditionally,
Although all the steps have to be performed in a dry room or a glove box with low moisture content, in the present invention, only the steps after the polymer film is impregnated with the electrolytic solution may be performed in the glove box or the like.

In order to make the olefin / maleimide copolymer into a sheet, first, the olefin / maleimide copolymer is dispersed and dissolved in a solvent. The solvent at this time may be appropriately selected from various solvents in which the olefin / maleimide copolymer can be dissolved, for example, tetrahydrofuran (TH
F), dimethylformamide (DMF), N-methylpyrrolidone (NMP) and the like are preferably used. The concentration of the olefin / maleimide copolymer in the solvent is preferably 5 to 30% by weight. The dispersing and dissolving method is to dissolve simply by stirring at room temperature using a magnetic stirrer or the like. In order to dissolve the olefin / maleimide copolymer in a short time, heating may be performed at a temperature lower than the boiling point of the solvent.

Next, this olefin / maleimide copolymer solution is applied on a substrate and cast to form a sheet. The substrate may be any smooth material. For example, polyester film, glass, polytetrafluoroethylene film, and the like. The means for applying the olefin / maleimide copolymer solution to the substrate is not particularly limited, and may be appropriately determined according to the material and shape of the substrate. Generally, a metal mask printing method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, a screen printing method, and the like are used.

The sheet thus obtained is left or heat-treated to evaporate the solvent used when the olefin / maleimide copolymer is dissolved. Then, the SPE of the present invention can be obtained by impregnating the sheeted olefin / maleimide copolymer film with an electrolytic solution. Impregnation is usually
The electrolyte solution is uniformly dropped on the polymer film and left at room temperature to swell the electrolyte solution into the polymer. Alternatively, the polymer film may be immersed in the electrolyte solution. Lithium batteries,
Any material may be used as long as it is used for an electric double layer capacitor or the like and has good compatibility with the copolymer.

The conventional method, that is, olefin
The maleimide copolymer is dissolved in a solvent, the electrolytic solution is mixed, the olefin / maleimide copolymer solution is applied to a substrate, cast into a sheet, and the sheet is left or heat-treated to leave the olefin / maleimide. SPE can also be obtained by evaporating the solvent used to dissolve the copolymer.

The olefin / maleimide copolymer may be directly dissolved in the electrolyte.

The thickness of the SPE of the present invention is usually 10 to 5
00 μm.

<Filler> If the strength, rigidity, pressure resistance, adhesiveness, etc. of the above-mentioned SPE are inconvenient, an inorganic or organic filler (filler) such as silica or alumina is added to the SPE.
Can improve them. The material, particle size, shape and filling amount of the filler to be added are not particularly limited, but the ionic conductivity of the SPE essentially decreases with the filling amount. It is preferable that the filling amount is 30% by weight or less.

If the SPE is not self-sustaining, a nonwoven fabric or the like may be included in the SPE as a support for the SPE.

<Electrochemical Device> The SPE of the present invention comprises:
It can be used for electrochemical devices such as batteries, capacitors, EC displays, sensors and the like, and can be particularly suitably used for lithium secondary batteries and electric double layer capacitors.

<Lithium Secondary Battery> Although the structure of a lithium secondary battery using the polymer solid electrolyte of the present invention is not particularly limited, it is usually composed of a positive electrode, a negative electrode, and SPE, and is usually a laminated battery or a cylindrical battery. Applied to batteries and the like.

The electrode to be combined with SPE may be appropriately selected from those known as electrodes for a lithium ion secondary battery, and a composition of an electrode active material and SPE may be used.

The negative electrode comprises a negative electrode active material such as carbon, lithium metal, lithium alloy or oxide material, and the positive electrode comprises a positive electrode such as oxide or carbon capable of intercalating / deintercalating lithium ions. Made of active material. By using such an electrode, a lithium secondary battery having excellent characteristics can be obtained.

The carbon used as the active material may be appropriately selected from, for example, natural or artificial graphite, resin-fired carbon material, carbon fiber and the like. These are used in powder.
Of these, graphite is preferred, and its average particle size is preferably 1 to 30 μm, particularly preferably 5 to 25 μm. If the average particle size is too small, the charge / discharge cycle life tends to be short and the variation in capacity (individual difference) tends to be large. If the average particle size is too large, the dispersion of the capacity becomes extremely large, and the average capacity becomes small. It is considered that the capacity variation occurs when the average particle size is large because the contact between the graphite and the current collector and the contact between the graphites vary.

The oxide capable of intercalating / deintercalating lithium ions is preferably a composite oxide containing lithium, for example, LiCoO ₂ , LiM
_{n 2 O 4, LiNiO 2,} LiV 2 O 4 and the like.
The average particle diameter of these oxide powders is preferably about 1 to 40 μm.

A conductive assistant is added to the electrode if necessary. Preferred examples of the conductive auxiliary agent include metals such as graphite, carbon black, carbon fiber, nickel, aluminum, copper, and silver. Particularly, graphite and carbon black are preferable.

The electrode composition is such that when a gel electrolyte is added as a binder, the weight ratio of active material: conductive additive:
The gel electrolyte is preferably in the range of 10 to 50: 0 to 20:30 to 90. In the negative electrode, the active material: the conductive auxiliary agent:
The gel electrolyte is preferably in the range of 10 to 50: 0 to 20:30 to 90. An electrode containing no gel electrolyte is also preferably used. In this case, a fluorine resin, a fluorine rubber, or the like can be used as the binder, and the amount of the binder is 3 to 30 wt.
%.

In the present invention, the above-mentioned negative electrode active material and / or positive electrode active material, preferably both active materials, are preferably mixed in the above-mentioned binder solution and adhered to the surface of the current collector. When a gel electrolyte is used as the binder, one having the same composition as the SPE of the present invention or one having another composition may be used.

In manufacturing an electrode, first, an active material and, if necessary, a conductive auxiliary are dispersed in a binder solution to prepare a coating solution.

Then, this electrode coating solution is applied to the current collector. The means for applying is not particularly limited, and may be determined as appropriate according to the material and shape of the current collector. Generally, a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, a screen printing method, and the like are used.
Thereafter, if necessary, a rolling treatment is performed by a flat plate press, a calender roll, or the like.

The current collector may be appropriately selected from ordinary current collectors according to the shape of the device used by the battery, the method of arranging the current collector in the case, and the like. Generally, aluminum or the like is used for the positive electrode, and copper, nickel, or the like is used for the negative electrode.
Note that a metal foil, a metal mesh, or the like is usually used as the current collector. Although the metal mesh has a smaller contact resistance with the electrode than the metal foil, a sufficiently small contact resistance can be obtained with the metal foil.

Then, the solvent is evaporated to form an electrode. The coating thickness is preferably about 50 to 1,000 μm.

<Electric Double Layer Capacitor> The structure of the electric double layer capacitor using the solid polymer electrolyte of the present invention is not particularly limited.
And an insulating gasket is arranged around the polarizable electrode and the SPE. Such an electric double layer capacitor may be any type called a coin type, a paper type, a laminated type, or the like.

For the polarizable electrode, activated carbon, activated carbon fiber, or the like is used as a conductive active material, and a fluororesin, a fluororubber, or the like is added as a binder. Then, it is preferable to use the mixture formed on a sheet-like electrode. The amount of the binder is about 5 to 15 wt%. Further, a gel electrolyte may be used as the binder. In this case, the gel electrolyte may have the same composition as the SPE of the present invention or may have another composition.

The current collector used for the polarizable electrode is platinum,
It may be a conductive rubber such as a conductive butyl rubber or the like, may be formed by spraying a metal such as aluminum or nickel, or may be provided with a metal mesh on one surface of the electrode layer.

The electric double layer capacitor is obtained by combining the above-mentioned polarizable electrode and the above-mentioned SPE.

As the electrolyte salt, (C ₂ H ₅ ) ₄ NB
F ₄ , (C ₂ H ₅ ) ₃ CH ₃ NBF ₄ , (C ₂ H ₅ ) ₄ PB
F _4, and the like.

The non-aqueous solvent used for the electrolytic solution may be various known ones, and propylene carbonate, ethylene carbonate, γ-
Butyrolactone, acetonitrile, dimethylformamide, 1,2-dimethoxyethane, sulfolane alone or a mixed solvent is preferred.

The concentration of the electrolyte in such a non-aqueous solvent-based electrolyte solution may be 0.1 to 3 mol / l.

As the insulating gasket, an insulator such as polypropylene or butyl rubber may be used.

[0113]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples.

Example 1 The following olefin / maleimide copolymer film (thickness: 80 μm) was sufficiently dried and cut into a diameter of 19 mm.

[0115]

Embedded image

Then, in a glove box filled with argon gas, 50 mg of 1 mol / l- (C ₂ H ₅ ) ₄ NBF ₄ /
A propylene carbonate (abbreviation: PC) electrolytic solution was uniformly dropped, and the solution was allowed to stand at room temperature for 12 hours to swell the electrolytic solution, thereby producing a gel-type SPE.

The weight change rate before and after swelling (swelling degree)
Sw was determined, and the ionic conductivity σ was measured by the following method.

<Ion Conductivity Measurement Method> A test piece of 1 cm ² was cut out from the obtained SPE film, and the AC impedance between the electrodes was measured in a glove box using a conductivity measurement cell using SUS electrodes ( Frequency 1 to 10 ⁶ H
z). Ionic conductivity was determined by complex impedance analysis. The measuring apparatus used was a SI1255 type impedance analyzer manufactured by Solartron.

Table 1 shows the measured swelling degree Sw and ionic conductivity σ of the sample.

[0120]

[Table 1]

[Example 2] 1 mol / l-LiPF
₆ / Ethylene carbonate (EC) + dimethyl carbonate (DMC) (EC: DMC = 1: 1) An SPE was prepared and evaluated in the same manner as in Example 1 except that an electrolytic solution was used. Table 1 shows the results.

Comparative Example 1 VDF: HFP = 90: 10
6 g of a wt% VDF-HFP copolymer (manufactured by KynarFlex 2801 Elf Atochem) is dissolved in 30 g of methyl ethyl ketone, and 14 g of a 1M (C ₂ H ₅ ) ₄ NBF ₄ / PC solution is added and mixed. Coating and casting
The solvent was removed by drying to produce an SPE (80 μm thickness). The above operation was performed in a glove box filled with argon gas. And it evaluated similarly to Example 1. Table 1 shows the results.

The SPE of the present invention exhibited a swelling property and ionic conductivity equal to or higher than those of the comparative example. The SPEs of Examples 1 and 2 were about 20% lighter than the SPE of Comparative Example 1 using the VDF-HFP copolymer.

The same result was obtained by using the olefin / maleimide copolymer of No. 3 in Chemical formula 10.

Example 3 An electric double-layer capacitor using the SPE of Example 1 was manufactured as follows.

A predetermined amount of N, N-
While dimethylformamide (DMF) and Cefralsoft G180 manufactured by Central Glass Co., Ltd. (comprising vinylidene fluoride-3fluoroethylene copolymer as the main chain and polyvinylidene fluoride in the side chain) were added thereto, and the mixture was heated. It was dispersed and dissolved at 3500 rpm to 7000 rpm. Further DMF was added to this solution,
Dispersed and dissolved at pm. The concentration of Cefral soft solution is 10
wt%.

Powdery coconut shell activated carbon (average particle size: 10 μm) was added to 40 g of the above Cefral soft solution as an electrode active material.
20) and 1 g of acetylene black were added and mixed. Then, this paste was applied on a stainless steel foil, and DMF was removed by drying to obtain a polarizable electrode.

The polarizable electrode was formed into a circular shape having a diameter of 15 mm.
SPE of Example 1 cut out to 20 mm in diameter
The film is sandwiched between the pair of electrodes, inserted into an aluminum laminate bag, and the lead take-out portion is heat-sealed to remove the electricity.
A multilayer capacitor was manufactured.

With this capacitor, charge / discharge was confirmed between 1-2 V at a current density of 1 mA / cm ² , and it was found that there was no problem in the adhesion between the SPE and both electrodes. No deterioration of the characteristics was observed even after 3 days.

Example 4 A lithium ion secondary battery using the SPE of Example 2 was manufactured as follows.

Cefral soft solution 4 prepared in Example 3
0 g was placed in a container of a homogenizer, and lithium cobaltate (manufactured by Seimi Chemical Co., particle size 2-3) was used as a positive electrode active material.
μm) and 3 g of acetylene black (trade name: HS-100, manufactured by Denki Kagaku Kogyo KK).
The mixture was dispersed and mixed at room temperature for 5 minutes at room temperature to obtain a coating solution for a positive electrode.

This coating solution was applied to an aluminum foil (30 mm long, 30 mm wide).
mm, thickness 30μm) with a metal mask printing machine to a diameter of 15mm
, And left for 24 hours to evaporate DMF to obtain a positive electrode. The thickness of this electrode was 0.15 mm.

40 g of the above cefral soft solution was placed in a homogenizer container, and 9 g of graphite (trade name: SFG25, manufactured by Lonza, 90% cumulative particle size 25 μm) was used as a negative electrode active material.
Was added and dispersed and mixed at 12,000 rpm for 5 minutes at room temperature to obtain a coating solution for a negative electrode.

This coating solution was coated with copper foil (length 30 mm, width 30 mm,
It was printed in a circular shape with a diameter of 15 mm on a metal mask printer at a thickness of 30 μm) and left for 24 hours to evaporate DMF to obtain a negative electrode. The thickness of this electrode was 0.15 mm.

The two metal foils were cut into a circle having a diameter of 15 mm, and the S foil having a diameter of 17 mm prepared in Example 2 was cut between the coating films.
A coin-type lithium ion secondary battery was fabricated by sandwiching the PE film and sealing the periphery with a polyolefin-based hot melt adhesive.

This lithium ion battery has a capacity of 0.1 mA / cm ²
It was possible to charge and discharge between 2 and 4 V at a current density of, and it was confirmed that the battery was operated normally, and it was found that there was no problem in the adhesion between the SPE and both electrodes.

[0137]

As described above, according to the present invention, a polymer solid electrolyte which can be easily produced without using a plasticizer, has a high ionic conductivity and can be reduced in weight, and By using this, it is possible to provide an electrochemical device having high productivity and mass productivity and excellent characteristics.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhide Oe 1-1-13 Nihonbashi, Chuo-ku, Tokyo FDT term in TDK Corporation (reference) 5G301 CA08 CA16 CA30 CD01 5H024 AA01 AA02 FF23 5H026 CX04 EE05 EE08 EE12 EE18 5H029 AJ14 AK02 AK06 AL02 AL06 AL12 AM03 AM04 AM07 AM16 EJ12

Claims (8)

[Claims] 1. A polymer solid electrolyte containing an olefin / maleimide copolymer of an N-alkylmaleimide and an olefin, and an electrolytic solution. 2. The polymer solid according to claim 1, wherein the olefin / maleimide copolymer has a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). Electrolytes. Embedded image Embedded image (In the formula (1), R ₁ , R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms or a hydrogen atom,
In the formula (2), R ₄ represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a hydrogen atom. ) 3. The structural unit represented by the formula (1) is 70 to 2 mol% of the olefin / maleimide copolymer, and the structural unit represented by the formula (2) is the olefin / maleimide. 3. The polymer solid electrolyte according to claim 2, which is 30 to 98 mol% of the maleimide copolymer. 4. The polymer solid electrolyte according to claim 3, wherein the olefin / maleimide copolymer has a structural unit represented by the following general formula (I). Embedded image (In the general formula (I), R ₁ , R ₂ and R ₃ each represent an alkyl group having 1 to 8 carbon atoms or a hydrogen atom, and R ₄ represents an alkyl group having 1 to 18 carbon atoms and 3 carbon atoms. ~
Represents 12 cycloalkyl groups or hydrogen atoms. ) 5. The polymer solid electrolyte according to claim 2, wherein R ₁ is hydrogen, R ₂ and R ₃ are each a methyl group, and R ₄ is a methyl group. 6. The weight average molecular weight of the olefin / maleimide copolymer is from 1 × 10 ³ to 1 in terms of polystyrene.
The solid polymer electrolyte according to any one of claims 1 to 5, which is × 10 ⁷ . 7. An electrochemical device using the solid polymer electrolyte according to claim 1. 8. The electrochemical device according to claim 7, which is a lithium secondary battery or an electric double layer capacitor.