JP2003208816A - Electrolyte composition and battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolyte composition having excellent mechanical characteristics and ion conductivity. <P>SOLUTION: This electrolyte composition contains (1) a polymer having ether linkage which may have a crosslinkable functional group, (2) an additive containing an organic silicon compound having an ethylene oxide unit, and (3) an electrolytic salt compound. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrolyte composition containing a polymer compound, an additive and an electrolyte salt compound, and particularly, an electrolyte composition suitable as a material for electrochemical devices such as batteries, capacitors and sensors. Regarding things.

[0002]

2. Description of the Related Art Conventionally, electrolytes that constitute electrochemical devices such as batteries, capacitors and sensors have been used in the form of solutions or pastes from the viewpoint of ionic conductivity, but there is a risk of damage to equipment due to liquid leakage. However, it has been pointed out that there are limitations to ultra-miniaturization and thinning of the device because of the need for a separator impregnated with an electrolytic solution. On the other hand, solid electrolytes such as inorganic crystalline substances, inorganic glass, and organic polymer substances have been proposed. Organic polymer materials are generally excellent in workability and moldability, and the resulting solid electrolyte has flexibility and bendability,
The progress is expected from the standpoint of increasing the degree of freedom in the design of applied devices. However, at present, it is inferior to other materials in terms of ion conductivity.

The discovery of ionic conductivity in homopolymers of ethylene oxide and alkali metal ion systems has led to active research on polymer solid electrolytes. As a result, polyethers such as polyethylene oxide are considered to be the most promising polymer matrix in terms of its high mobility and solubility of metal cations. It is predicted that the migration of ions will occur in the amorphous part of the polymer rather than the crystalline part. Since then, copolymerization with various epoxides has been carried out in order to reduce the crystallinity of polyethylene oxide. Japanese Examined Japanese Patent Sho 62-2
Japanese Patent No. 49361 discloses a solid electrolyte composed of a copolymer of ethylene oxide and propylene oxide.
SP 4,818,644 discloses a solid electrolyte composed of a copolymer of ethylene oxide and methyl glycidyl ether. However, the ionic conductivity was not always satisfactory in all cases.

An attempt to incorporate a specific alkali metal salt into a diethylene glycol methyl glycidyl ether-ethylene oxide copolymer and apply it to a polymer solid electrolyte has been proposed in Japanese Patent Application Laid-Open No. 9-324114 including the applicant of the present invention. However, practically sufficient conductivity values have not been obtained.

[0005]

An object of the present invention is to provide an electrolyte composition having excellent mechanical properties and ionic conductivity.

[0006]

The present invention comprises (1) a polymer having an ether bond which may have a crosslinkable functional group, and (2) an additive containing an organosilicon compound having an ethylene oxide unit. And (3) an electrolyte salt compound, wherein the polymer (1) having an ether bond is (1-1) a constitutional unit represented by the following formula (i) and the following formula (1): a copolymer having a structural unit represented by ii), and / or (1-2) a structural unit (i), a structural unit (ii), and the following formula (iii)
Which is a copolymer having a cross-linkable constitutional unit represented by the following formula (2) containing an organosilicon compound having an ethylene oxide unit and having the following formulas (iv), (v) and (vi): Provided is an electrolyte composition selected from the group consisting of organosilicon compounds having an ethylene oxide unit represented.

[0007]

[Chemical 7]

[Chemical 8] [In the formula, R ¹ is an alkyl group or -CH ₂ -O-(-CH ₂ -CH _{2-
O-) n} -CH ₃ or _{-CH 2 -O-CH [(-} CH 2 -CH 2 -O-) n -CH 3]
Represents ₂ , and n is an integer of 0-12. ]

[Chemical 9] [In the formula, R ² represents a functional group having a reactive functional group. ]

[Chemical 10] ^{Wherein, A 11, A 12, A} 13 and ^{A 14} may be different from each _{other, - (- CH 2) p} - ( where, p is an integer of 0 to 3.)
X < ¹¹ >, X < ¹² >, X <^13> and X < ¹⁴ > may be different and each represent a methyl group, an ethyl group, a propyl group or a butyl group, and a, b, c and d are integers of 1 to 50. ]

[Chemical 11] [In the formula, A ²¹ , A ²² and A ²³ may be different from each other and represent-(-CH ₂ ) _p- (where p is an integer of 0 to 3),
X ²¹ , X ²² , X ²³ and X ²⁴ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, and h, i and j are integers of 1 to 50. ]

[Chemical 12] [In the formula, A ³¹ and A ³² may be different from each other, and-(-C
H ₂ ) _p − (where p is an integer of 0 to 3), and X ³¹ , X
³² , X ³³ , X ³⁴ , X ³⁵ and X ³⁶ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, s and u are integers of 1 to 50, and t is 0 to 1
An integer of 0, t <s and t <u. ]

The present invention further provides (1) a crosslinked polymer obtained by crosslinking a polymer having an ether bond, (2) an additive containing an organosilicon compound having an ethylene oxide unit, and (3) an electrolyte containing an electrolyte salt compound. A composition is provided. In addition, the present invention also provides a battery using the electrolyte composition.

The crosslinked body of the electrolyte composition is used when shape stability at high temperature is required. It has also been found that a high-performance battery having a low internal resistance can be obtained by using the electrolyte composition of the present invention. The electrolyte composition of the present invention may be in the form of gel. Here, the gel is a polymer swollen with a solvent (for example, water and / or an organic solvent).

The polymer (1) having an ether bond is
(1-1) A copolymer having a structural unit represented by the following formula (i) and a structural unit represented by the following formula (ii), or (1-2) the structural unit (i) A copolymer having a structural unit (ii), and a crosslinkable structural unit represented by the following formula (iii) is preferable.

[0011]

[Chemical 13]

[Chemical 14] [In the formula, R¹Is an alkyl group (eg C₁~ C₂₀, Preferred
It is C₁~ C₁₀More preferably C₁~ C_ThreeThe al
Kill group) or -CH_Two-O-(-CH_Two-CH_Two-O-)_n-CH _ThreeAlso
Is -CH_Two-O-CH [(-CH_Two-CH_Two-O-)_n-CH_Three]_TwoRepresents, and n is 0
It is an integer of ≦ n ≦ 12. ]

[0012]

[Chemical 15] [In the formula, R ² represents a functional group having a reactive functional group. ]

The monomer constituting the structural unit (i) in the polymer (1) is ethylene oxide.

The oxirane compound constituting the structural unit (ii) in the polymer (1) includes an alkylene oxide which may have a substituent and a glycidyl ether compound. Specifically, propylene oxide, methyl glycidyl ether, butyl glycidyl ether, styrene oxide, phenyl glycidyl ether, oxirane compounds such as 1,2-epoxyhexane, ethylene glycol methyl glycidyl ether, diethylene glycol methyl glycidyl ether, triethylene glycol methyl glycidyl Examples thereof include ether, 1,3-bis (2-methoxyethoxy) propane 2-glycidyl ether, and 1,3-bis [2- (2-methoxyethoxy) ethoxy] propane 2-glycidyl ether.

The reactive functional group of the oxirane compound forming the crosslinkable structural unit (iii) in the polymer (1) is (a) a reactive silicon group, (b) a methylepoxy group,
(C) an ethylenically unsaturated group, or (d) a halogen atom.

The oxirane compound having a reactive silicon group (a) includes 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane,
3-glycidoxypropyltrimethoxysilane, 4-glycidoxybutylmethyltrimethoxysilane, 3- (1,2-epoxy) propyltrimethoxysilane, 4- (1,2-epoxy)
Butyltrimethoxysilane, 5- (1,2-epoxy) pentyltrimethoxysilane, 1- (3,4-epoxycyclohexyl) methylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. Can be mentioned. Of these, 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane are particularly preferred.

The oxirane compound having a methylepoxy group (b) includes 2,3-epoxypropyl-2 ', 3'-epoxy-
2'-methylpropyl ether, ethylene glycol-2,3-
Epoxypropyl-2 ', 3'-epoxy-2'-methylpropyl ether, and diethylene glycol-2,3-epoxypropyl-2', 3'-epoxy-2'-methylpropyl ether, 2
-Methyl-1,2,3,4-diepoxybutane, 2-methyl-1,2,4,5
-Diepoxypentane, 2-methyl-1,2,5,6-diepoxyhexane, hydroquinone-2,3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropyl ether, catechol-2,3 -
Epoxypropyl-2 ', 3'-epoxy-2'-methylpropyl ether and the like can be mentioned.

Among them, especially 2,3-epoxypropyl-
2 ', 3'-epoxy-2'-methylpropyl ether and ethylene glycol-2,3-epoxypropyl-2', 3'-epoxy
-2'-methylpropyl ether is preferred.

The oxirane compound having an ethylenically unsaturated group (c) includes allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpinyl glycidyl ether, cyclohexenyl methyl glycidyl ether, p-vinylbenzyl glycidyl ether, Allylphenyl glycidyl ether, vinyl glycidyl ether, 3,4-epoxy-1-butene, 3,4-epoxy-1-pentene, 4,5-epoxy-2-pentene, 1,2-epoxy-5,9-cyclo Dodecadiene, 3,4-epoxy-1-vinylcyclohexene, 1,2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate, glycidyl crotonic acid, glycidyl-4- Hexenoate is used. Preferred are allyl glycidyl ether, glycidyl acrylate, and glycidyl methacrylate.

The oxirane compound having a halogen atom (d) includes epibromohydrin, epiiodohydrin,
Epichlorohydrin etc. are mentioned.

The polymerization method of a polymer having an ether bond is a polymerization method of obtaining a multicomponent copolymer by a ring-opening reaction of an ethylene oxide moiety.
It is carried out in the same manner as the method described in JP-A-4736 and JP-A-62-169823.

The polymerization reaction can be carried out as follows. Using an organoaluminum-based catalyst system, an organozinc-based catalyst system, an organotin-phosphate ester condensate catalyst system, etc. as a ring-opening polymerization catalyst, each monomer in the presence or absence of a solvent A polyether copolymer is obtained by reacting at a reaction temperature of 10 to 80 ° C. under stirring. Among them, the organotin-phosphoric acid ester condensate catalyst system is particularly preferable from the viewpoint of the degree of polymerization or the properties of the copolymer produced. The reactive functional group does not react in the polymerization reaction, and the polymer (1) having a reactive functional group is obtained.

The ratio of ethylene oxide constituting the structural unit (i) to the polymer having an ether bond used in the electrolyte composition of the present invention is 10 to 95 parts by weight, preferably 20 to 90 parts by weight. The amount of the oxirane compound constituting the) is 90 to 5 parts by weight, preferably 80 to
10 parts by weight, 0 to 30 parts by weight, preferably 0 to 20 parts by weight of the oxirane compound constituting the crosslinkable structural unit (iii).

When the amount of the oxirane compound constituting the crosslinkable structural unit (iii) is 30 parts by weight or less, the crosslinked polymer has good ionic conductivity.

When the amount of ethylene oxide constituting the structural unit (i) is 10 parts by weight or more, the electrolyte salt compound is easily dissolved even at a low temperature, so that the ionic conductivity is high. Although it is generally known that the ionic conductivity is improved by lowering the glass transition temperature, it was found that the electrolytic composition of the present invention has a remarkably large effect of improving the ionic conductivity.

The polymer used in the electrolyte composition has a weight average molecular weight of 10 ⁴ to 10 ⁷ , preferably 10 ⁵ to 10 in order to obtain good processability, moldability, mechanical strength and flexibility. Those within the range of 5 × 10 ⁶ are suitable.

The polymer (1) whose reactive functional group is the reactive silicon group (a) can be crosslinked by a reaction between the reactive silicon group and water. To enhance the reactivity, tin compounds such as dibutyltin dilaurate and dibutyltin malate, titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, aluminum compounds such as aluminum trisacetylacetonate and aluminum trisethylacetoacetate, etc. An organometallic compound or an amine compound such as butylamine or octylamine may be used as a catalyst.

Polyamines, acid anhydrides and the like are used in the crosslinking method of the polymer (1) having a reactive functional group of the methylepoxy group (b). Examples of the polyamines include aliphatic polyamines such as diethylenetriamine and dipropylenetriamine, aromatic polyamines such as 4,4′-diaminodiphenyl ether, diaminodiphenyl sulfone, m-phenylenediamine and xylylenediamine. The amount of polyamine added varies depending on the type of polyamine, but is usually 0.1 to 10 per 100 parts by weight of the electrolyte composition excluding the plasticizer (that is, additive (2)).
The range is parts by weight.

Examples of the acid anhydrides include maleic anhydride, phthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrophthalic anhydride and the like. The amount of the acid anhydride added varies depending on the type of the acid anhydride, but usually, the electrolyte composition 10 excluding the plasticizer is used.
It is in the range of 0.1 to 10 parts by weight with respect to 0 parts by weight. An accelerator may be used for these crosslinking, and there are phenol, cresol, resorcin, etc. for the crosslinking reaction of polyamines, and benzyldimethylamine, 2- (dimethylaminoethyl) phenol for the crosslinking reaction of acid anhydrides. , Dimethylaniline, etc. The amount of the accelerator added varies depending on the accelerator, but is usually 0.1 to 1 with respect to 100 parts by weight of the crosslinking agent.
It is in the range of 0 parts by weight.

The reactive functional group is an ethylenically unsaturated group (c)
As the method for crosslinking the polymer (1), a radical initiator selected from organic peroxides, azo compounds and the like, and active energy rays such as ultraviolet rays and electron rays are used. Further, a crosslinking agent containing silicon hydride can be used.

Examples of organic peroxides include ketone peroxide, peroxyketal, hydroperoxide,
Dialkyl peroxide, diacyl peroxide,
The ones that are usually used for crosslinking such as peroxyester are used, and 1,1-bis (t-butylperoxy) -3,3,5
-Trimethylcyclohexane, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, benzoyl peroxide, etc. Can be mentioned.
The amount of the organic peroxide added varies depending on the type of the organic peroxide, but is usually in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the electrolyte composition excluding the plasticizer.

As the azo compound, an azonitrile compound,
Azoamide compounds, azoamidine compounds and the like which are usually used for crosslinking are used, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2 '-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2'-azobis [2- (2-imidazoline -2-yl) propane], 2,2'-azobis [2-methyl-N-
(2-hydroxyethyl) propionamide], 2,2′-azobis (2-methylpropane), 2,2′-azobis [2- (hydroxymethyl) propionitrile] and the like. The amount of the azo compound added varies depending on the type of the azo compound, but is usually 0.1 per 100 parts by weight of the electrolyte composition excluding the plasticizer.
Within the range of 10 parts by weight.

For crosslinking by irradiation with active energy rays such as ultraviolet rays, glycidyl acrylate, glycidyl methacrylate, and glycidyl cinnamic acid are particularly preferable. Further, as a sensitization aid, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, acetophenones such as phenylketone,
Benzoin, benzoin ethers such as benzoin methyl ether, benzophenones, benzophenones such as 4-phenylbenzophenone, 2-isopropylthioxanthone, thioxanthones such as 2,4-dimethylthioxanthone, 3-sulfonylazidebenzoic acid, 4-sulfonylazidobenzoic acid Azides such as acids can be optionally used.

As a crosslinking aid, ethylene glycol diacrylate, ethylene glycol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene glycol dimethacrylate, allyl metal acrylate,
Allyl acrylate, diallyl maleate, triallyl isocyanurate, bisphenyl maleimide, maleic anhydride and the like can be optionally used.

As the compound having a silicon hydride bridging the ethylenically unsaturated group (c), a compound having at least two silicon hydrides is used. A polysiloxane compound or a polysilane compound is particularly preferable. The polysiloxane compound is represented by formula (a-1) or (a-2)
A chain polysiloxane compound represented by the formula, or (a-
There is a cyclic polysiloxane compound represented by the formula 3).

[0036]

[Chemical 16]

[0037]

[Chemical 17]

[0038]

[Chemical 18]

However, in the formulas (a-1) to (a-3),
R¹⁰, R¹¹, R¹², R^Thirteen, R ¹⁴, R¹⁵, R¹⁶,
R¹⁷ And R¹⁸May be different from each other, a hydrogen atom or
Represents an alkyl group or an alkoxy group having 1 to 12 carbon atoms.
, N ≧ 2, m ≧ 0, 2 ≦ m + n ≦ 300 (m or
And n is an integer). Alkyl groups include methyl and ethyl
Lower alkyl groups such as propyl, propyl and butyl are preferred.
Good As the alkoxy group, methoxy group, ethoxy group
Group, propoxy group, butoxy group and other lower alkoxy groups
Is preferred.

As the polysilane compound, a chain polysilane compound represented by the formula (b-1) is used.

[Chemical 19]

However, in the formula (b-1), R ¹⁹ ,
R ²⁰ , R ²¹ , R ²² and R ²³ may be different from each other and represent a hydrogen atom or an alkyl group or an alkoxy group having 1 to 12 carbon atoms, and n ≧ 2, m ≧ 0, 2 ≦ m + n ≦ 100 ( m and n are integers).

Examples of catalysts for the hydrosilylation reaction include:
Examples thereof include transition metals such as palladium and platinum, their compounds, and complexes. Further, peroxides, amines and phosphines are also used. The most common catalyst is dichlorobis
(Acetonitrile) palladium (II), chlorotris
(Triphenylphosphine) rhodium (I) and chloroplatinic acid are mentioned.

As a method for crosslinking the polymer (1) having an ether bond whose reactive functional group is a halogen atom (d), crosslinking agents such as polyamines, mercaptoimidazolines, mercaptopyrimidines, thioureas and polymercaptans can be used. Is used. Examples of polyamines include triethylenetetramine and hexamethylenediamine. Examples of mercaptoimidazolines include 2-mercaptoimidazoline and 4-methyl-2-mercaptoimidazoline. Examples of mercaptopyrimidines include 2-mercaptopyrimidine and 4,6-dimethyl-2-mercaptopyrimidine. Examples of thioureas include ethylene thiourea and dibutyl thiourea.
As polymercaptans, 2-dibutylamino-4,6-dimethylcapto-s-triazine, 2-phenylamino-4,6-
Examples include dimercaptotriazine and the like. The addition amount of the cross-linking agent varies depending on the type of the cross-linking agent, but is usually in the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of the electrolyte composition excluding the plasticizer.

Further, it is effective from the viewpoint of the thermal stability of the halogen-containing polymer to add a metal compound serving as an acid acceptor to the polymer solid electrolyte. Examples of the metal oxide that serves as such an acid acceptor include oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, and periodic metals of Group II metals of the periodic table. Group VIa metal oxides, basic carbonates, basic carboxylates, basic phosphites,
There are basic sulfite, tribasic sulfate and the like. Specific examples include magnesia, magnesium hydroxide, magnesium carbonate, calcium silicate, calcium stearate, red lead, tin stearate, and the like.
The amount of the metal compound serving as the acid acceptor to be mixed varies depending on the type, but is usually in the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of the electrolyte composition excluding the plasticizer.

The additive (2) containing an organosilicon compound is
Functions as a plasticizer. When the additive (2) containing an organosilicon compound having an ethylene oxide unit is added to the electrolyte composition, crystallization of the polymer is suppressed, the glass transition temperature is lowered, and many amorphous phases are formed even at low temperatures, resulting in ion conduction. The degree will improve.

The organosilicon compound may be a compound having no silicon-oxygen bond (siloxane bond) or a compound having a silicon-oxygen bond (siloxane bond). In the organosilicon compound having no siloxane bond, the number of silicon atoms may be one. In the organosilicon compound having a siloxane bond, the number of silicon atoms may be 1 or 2-11. The organosilicon compound has at least four molecular ends, but all molecular ends may be methyl groups.

Examples of the organosilicon compound having an ethylene oxide unit are preferably organosilicon compounds having an ethylene oxide unit represented by the following formulas (iv), (v) and (vi).

[Chemical 20] ^{Wherein, A 11, A 12, A} 13 and ^{A 14} may each _{differently, - (- CH 2) p} - ( where, p is an integer of 0 to 3.)
X < ¹¹ >, X < ¹² >, X <^13> and X < ¹⁴ > may be different and each represent a methyl group, an ethyl group, a propyl group or a butyl group, and a, b, c and d are 1 to 50, preferably 1 to It is an integer of 10. ]

[0048]

[Chemical 21] [In the formula, A ²¹ , A ²² and A ²³ may be different from each other and represent-(-CH ₂ ) _p- (where p is an integer of 0 to 3),
X ²¹ , X ²² , X ²³ and X ²⁴ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, and h, i and j are 1 to 50, preferably 1 to 10
Is an integer. ]

[0049]

[Chemical formula 22] [In the formula, A ³¹ and A ³² may be different from each other, and-(-C
H ₂ ) _p − (where p is an integer of 0 to 3), and X ³¹ , X
³² , X ³³ , X ³⁴ , X ³⁵ and X ³⁶ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, and s and u are 1 to 50, preferably 1 to 1
An integer of 0, t is 0 to 10, preferably an integer of 0 to 5, t <s
And t <u. ]

The mixing ratio of the additive (2) is optional,
5 to 2,000 per 100 parts by weight of polymer (1)
Parts by weight, preferably 20 to 1,000 parts by weight.

The electrolyte salt compound (3) used in the present invention is preferably soluble in a mixture of the uncrosslinked or crosslinked polymer (1) and the plasticizer (2). In the present invention, the salt compounds listed below are preferably used.

That is, metal cation, ammonium ion
From aluminium, amidinium, and guanidinium ions
Selected cations, chlorine ions, bromine ions, iodine
Ion, perchlorate ion, thiocyanate ion, tetra
Fluoroborate ion, nitrate ion, AsF₆ ⁻, P
F₆ ⁻, Stearyl sulfonate, octyl sulfo
Nitrate ion, dodecylbenzene sulfonate ion, naphth
Talensulfonate ion, dodecylnaphthalene sulfone
Acid ion, 7,7,8,8-tetracyano-p-quinodimethaneio
N, X₁SO_Three ⁻, [(X₁SO_Two) (X_TwoSO_Two) N]⁻,
[(X₁SO_Two) (X _TwoSO_Two) (X_ThreeSO_Two) C]⁻,as well as
[(X₁SO_Two) (X_TwoSO_Two) YC]⁻ Yin selected from
And a compound consisting of ON. However, X₁,
X_Two, X_ThreeAnd Y are electron withdrawing groups. Preferably X
₁, X_Two, And X_ThreeEach independently has 1 to 6 carbon atoms
Perfluoroalkyl group or perfluoroaryl group
And Y is a nitro group, a nitroso group, a carbonyl group,
It is a ruboxyl group or a cyano group. X₁, X_TwoAnd X_Three
May be the same or different. Metal yang
As the ON, a transition metal cation can be used.
Preferably Mn, Fe, Co, Ni, Cu, Zn and A
A cation of a metal selected from g-metals is used. or,
Li, Na, K, Rb, Cs, Mg, Ca and Ba metals
Even when using a cation of a metal selected from
can get. Two kinds of the above compounds as electrolyte salt compounds
The above can be used together. Li-ion battery smell
As the electrolyte salt compound, Li salt compound is preferable.
Yes.

In the present invention, the electrolyte salt compound (3) is used in an amount of 1 to 100 parts by weight of the polymer (1).
The range is 50 parts by weight, preferably 3 to 20 parts by weight. When this value is 50 parts by weight or less, the processability, the moldability, the mechanical strength and flexibility of the obtained solid electrolyte are high, and the ion conductivity is also high.

When flame retardancy is required when using the electrolyte composition, a flame retardant can be used. As a flame retardant, brominated epoxy compounds, tetrabrom bisphenol A, halides such as chlorinated paraffin, antimony trioxide,
Add an effective amount selected from antimony pentoxide, aluminum hydroxide, magnesium hydroxide, phosphates, polyphosphates, and zinc borate.

The method for producing the electrolyte composition of the present invention is not particularly limited, but usually the respective components may be mechanically mixed. In the case of the polymer (1) which requires cross-linking, it is produced by a method of mechanically mixing the respective components and then cross-linking, but it may be impregnated by being immersed in a plasticizer for a long time after the cross-linking. . As means for mechanically mixing, various kneaders, open rolls, extruders and the like can be arbitrarily used.

When the reactive functional group is a reactive silicon group, the amount of water used for the cross-linking reaction is not particularly limited because it easily occurs due to humidity in the atmosphere. It is also possible to crosslink by passing it through cold water or a hot water bath for a short time, or by exposing it to a steam atmosphere. When the reactive functional group is an ethylenically unsaturated group, when a radical initiator is used, 10
The crosslinking reaction is completed in 1 minute to 20 hours under the temperature condition of ℃ to 200 ℃. Further, when utilizing energy rays such as ultraviolet rays, a sensitizer is generally used. Usually 10 ° C-15
The crosslinking reaction is completed within 0.1 second to 1 hour under the temperature condition of 0 ° C. The cross-linking agent having silicon hydride is 10 ° C to 180 ° C.
The cross-linking reaction is completed in 10 minutes to 10 hours under the temperature condition of.

Electrolyte salt compound (3) and additive (2)
There is no particular limitation on the method of mixing the polymer (1) with the polymer (1) (that is, the polyether copolymer), but a method of immersing the polyether copolymer in an organic solvent containing an electrolyte salt compound and an additive for a long time, and impregnating the same. A method of mechanically mixing an electrolyte salt compound and an additive into a polyether copolymer,
There are a method of dissolving and mixing the polyether copolymer and the electrolyte salt compound in an additive, a method of dissolving the polyether copolymer in another organic solvent once, and then mixing the additive. When using an organic solvent,
Various polar solvents such as tetrahydrofuran, acetone, acetonitrile, dimethylformamide, dimethylsulfoxide, dioxane, methyl ethyl ketone, methyl isobutyl ketone, etc. may be used alone or in combination.

The electrolyte composition shown in the present invention is excellent in mechanical strength and flexibility, and it is possible to easily obtain a solid electrolyte in the form of a large-area thin film by utilizing its properties. For example, a battery can be produced using the electrolyte composition of the present invention. In this case, the positive electrode material includes lithium-manganese composite oxide, lithium cobalt oxide, vanadium pentoxide, olivine-type iron phosphate, polyacetylene, polypyrene, polyaniline, polyphenylene, polyphenylene sulfide, polyphenylene oxide, polypyrrole, polyfuran, polyazulene, etc. . Examples of the negative electrode material include an intercalation compound in which lithium is intercalated between graphite or carbon layers, lithium metal, and a lithium-lead alloy. Further, it is also considered that cations such as alkali metal ions, Cu ions, Ca ions, and Mg ions are used as a diaphragm of an ion electrode by utilizing high electric conductivity. The electrolyte composition of the present invention is particularly suitable as a material for electrochemical devices such as batteries, capacitors and sensors.

[0059]

EXAMPLES The present invention will be described in detail below with reference to examples.

The monomer-converted composition of the polyether copolymer was determined by ¹ H NMR spectrum. Gel permeation chromatography measurement was performed to measure the molecular weight of the polyether copolymer, and the molecular weight was calculated by standard polystyrene conversion. Gel permeation chromatography measurement is made by Shimadzu Corporation RID-6
A, Showdex KD-8 column from Showa Denko KK
07, KD-806, KD-806M and KD-80
3 and the solvent dimethylformamide (DMF) at 60 ° C. The glass transition temperature and the heat of fusion were measured by using a differential scanning calorimeter DSC8230B manufactured by Rigaku Denki Co., Ltd., in a nitrogen atmosphere, a temperature range of −100 to 80 ° C., and a temperature rising rate of 10 ° C.
/ Min was measured. The sample film was vacuum-dried in advance at 30 ° C. for 12 hours in order to measure the conductivity σ. Conductivity is measured at 10 ° C., the film is sandwiched by SUS electrodes, voltage is 0.5 V, frequency range is 5 Hz to 1
It was calculated by the complex impedance method using the alternating current method of MHz.

Synthesis Example (Production of Catalyst) 10 g of tributyltin chloride and 35 g of tributyl phosphate were placed in a three-necked flask equipped with a stirrer, a thermometer and a distillation apparatus, and the mixture was stirred at 250 ° C. under a nitrogen stream.
The mixture was heated at 20 ° C. for 20 minutes to distill off the distillate to obtain a solid condensed substance as a residue. Thereafter, this was used as a polymerization catalyst.

Polymerization Example 1 (Production of Polymer) The inside of a glass 4-necked flask having an internal volume of 3 L was replaced with nitrogen, and the condensed substance 2 as a catalyst was used as a catalyst.
g and oxirane compound (EM-3) of the following formula (11) adjusted to 10 ppm or less of water and 1,000 g of n-hexane as a solvent were charged, and 70 g of ethylene oxide was EM-.
While tracking the polymerization rate of 3 by gas chromatography,
Sequentially added. The polymerization reaction was stopped with methanol. After removing the polymer by decantation, under normal pressure 4
200 g of a polymer was obtained by drying at 0 ° C. for 24 hours and further under reduced pressure at 45 ° C. for 10 hours. The glass transition temperature of this copolymer was −73 ° C., the weight average molecular weight was 1.4 million, and the heat of fusion was 3 J / g. The monomer conversion compositional analysis result of this copolymer by ¹ H NMR spectrum was 30% by weight of ethylene oxide,
EM-3 was 70 wt%.

[Chemical formula 23]

Polymerization Example 2 (Production of Polymer) The inside of a glass 4-necked flask having an internal volume of 3 L was replaced with nitrogen, and the condensed substance 2 shown in the production example of the catalyst was used as a catalyst.
g and 100 g of oxirane compound (GM) of the following formula (12) adjusted to 10 ppm or less of water, 10 g of allyl glycidyl ether and 1,000 g of n-hexane as a solvent were charged, and 120 g of ethylene oxide was traced by gas chromatography to check the polymerization rate of GM. While adding sequentially. The polymerization reaction was stopped with methanol. After the polymer was taken out by decantation, it was dried under normal pressure at 40 ° C. for 24 hours and further under reduced pressure at 45 ° C. for 10 hours to obtain 205 g of a polymer. The glass transition temperature of this copolymer was -74 ° C, the weight average molecular weight was 1.15 million, and the heat of fusion was 3 J / g. ¹ H N
The results of monomer-converted composition analysis of this copolymer by MR spectrum were 53 wt% ethylene oxide, 43 wt% GM, and 4 wt% allyl glycidyl ether.

[Chemical formula 24]

Polymerization Example 3 (Production of Polymer) The inside of a glass 4-necked flask having an internal volume of 3 L was replaced with nitrogen, and the condensed substance 2 as a catalyst was used as a catalyst.
g and 110 g of oxirane compound (EM-2) of the following formula (13) adjusted to a water content of 10 ppm or less, 18 g of glycidyl methacrylate and 1,000 g of n-hexane as a solvent were charged, and 90 g of ethylene oxide was gas chromatographed for the polymerization rate of EM-2. Sequential additions were made while following the graph. The polymerization reaction was stopped with methanol. After the polymer was taken out by decantation, it was dried under normal pressure at 40 ° C. for 24 hours and further under reduced pressure at 45 ° C. for 10 hours to obtain 200 g of the polymer. The glass transition temperature of this copolymer was −71 ° C., the weight average molecular weight was 1.05 million, and the heat of fusion was 5 J / g. ¹ H N
The results of compositional analysis of the monomer in terms of monomer by MR spectrum were 43 wt% ethylene oxide, 50 wt% EM-2 and 7 wt% glycidyl methacrylate.

[Chemical 25]

Example 1 1 g of the polymer obtained in Polymerization Example 1, 0.5 g of an additive having a siloxane bond represented by the following formula (14), and lithium bis (trifluoromethylsulfonyl) as a lithium salt compound.
0.7 g of imide (LiTFSI) was mixed in 50 g of acetonitrile until uniform, and then uniformly coated on a PET film. After that, it was dried under reduced pressure at 30 ℃ for 12 hours, and the film thickness was 50μm.
I got a film of. Ionic conductivity is 4.3 x 10 ^-4 S / cm
Met.

[Chemical formula 26]

Example 2 1 g of the polymer obtained in Polymerization Example 1, 1 g of an additive having a siloxane bond of the following formula (15), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) 0.7 g as a lithium salt compound, and initiation Benzoyl peroxide as an agent
0.015 g and 0.3 g of ethylene glycol diacrylate as a crosslinking aid were mixed in 50 g of acetonitrile until uniform, and then uniformly coated on a PET film. Then, dry under reduced pressure at 30 ° C for 12 hours, and then at 100 ° C for 2 hours.
Heating was performed in a nitrogen atmosphere to obtain a crosslinked film having a thickness of 50 μm. The ionic conductivity was 2.1 x 10 ^-4 S / cm.

[Chemical 27]

Example 3 1 g of the polymer obtained in Polymerization Example 3, 0.5 g of an additive having a siloxane bond of the following formula (16), and lithium bis (trifluoromethylsulfonyl) as a lithium salt compound.
Imide (LiTFSI) 0.6 g, benzoyl peroxide as an initiator
0.015 g was mixed in 50 g of acetonitrile until uniform, and then uniformly coated on a PET film. Then 30
It was dried under reduced pressure at 12 ° C. for 12 hours and further heated at 100 ° C. for 2 hours in a nitrogen atmosphere to obtain a crosslinked film having a thickness of 50 μm. The ionic conductivity was 8.2 x 10 ^-5 S / cm.

[Chemical 28] (Mw: 1,300 m / n = 2)

Example 4 Ethylene oxide / propylene oxide / glycidyl methacrylate terpolymer having a weight average molecular weight of 700,000
(Ethylene oxide 80 wt%, Propylene oxide 15 wt%,
Glycidyl methacrylate 5 wt%) 1 g, additive having a siloxane bond of the following formula (17) 2 g, lithium bis (trifluoromethylsulfonyl) as a lithium salt compound
Imide (LiTFSI) 0.7 g, benzoyl peroxide as an initiator
0.015 g and 0.3 g of ethylene glycol diacrylate as a crosslinking aid were mixed in 50 g of acetonitrile until uniform, and then uniformly applied to a PET film. After that, it was dried under reduced pressure at 30 ° C for 12 hours, and then at 100 ° C for 2 hours.
Heating was performed in a nitrogen atmosphere to obtain a crosslinked film having a thickness of 50 μm. The ionic conductivity was 1.0 x 10 ^-4 S / cm.

[Chemical 29]

Comparative Example 1 A film was formed in the same manner as in Example 1 except that the additive having a siloxane bond was not added. The ionic conductivity was 1.2 x 10 ^-5 S / cm.

Comparative Example 2 A crosslinked film was molded in the same manner as in Example 2 except that the additive having a siloxane bond was not added. The ionic conductivity was 2.1 x 10 ^-5 S / cm.

Comparative Example 3 A crosslinked film was molded in the same manner as in Example 3 except that the additive having a siloxane bond was not added. The ionic conductivity was 1.6 x 10 ^-5 S / cm.

Comparative Example 4 A crosslinked film was molded in the same manner as in Example 4 except that the additive having a siloxane bond was not added. The ionic conductivity was 6.2 x 10 ^-6 S / cm.

Example 5 A secondary battery was constructed by using the polymer solid electrolyte obtained in Example 2 as an electrolyte, a lithium metal foil as a negative electrode, and lithium cobalt oxide (LiCoO ₂ ) as a positive electrode active material. Polymer solid electrolyte size is 10 mm x 10 mm x 0.0
5 mm. Lithium foil size is 10 mm x 10 mm x
0.1 mm. Lithium cobalt oxide was prepared by mixing a predetermined amount of lithium carbonate and cobalt carbonate powder and then firing at 900 ° C. for 5 hours. Next, this was pulverized, and to 85 parts by weight of the obtained lithium cobalt oxide, 5 parts by weight of acetylene black, 10 parts by weight of the polymer obtained in Polymerization Example 2 and lithium bis (trifluoromethylsulfonyl) were added.
After adding 5 parts by weight of imide (LiTFSI) and mixing with a roll, 30
It was pressed into a size of 10 mm x 10 mm x 0.2 mm with a pressure of MPa to obtain a battery positive electrode.

The polymer solid electrolyte obtained in Example 2 was sandwiched between a lithium metal foil and a positive electrode plate so that the interface was adhered.
The charge / discharge characteristics of the battery were examined at 25 ° C. while applying a pressure of 1 MPa. The initial discharge voltage at the terminal voltage of 3.8 V is 0.1 mA /
cm ^2, and was chargeable at 0.1 mA / cm ^2. Since the battery of this embodiment can be easily made thin, the battery is lightweight and has a large capacity.

Example 6 A secondary battery was constructed by using the polymer solid electrolyte obtained in Example 3 as an electrolyte, a lithium metal foil as a negative electrode, and lithium cobalt oxide (LiCoO ₂ ) as a positive electrode active material. Polymer solid electrolyte size is 10 mm x 10 mm x 0.0
5 mm. Lithium foil size is 10 mm x 10 mm x
0.1 mm. Lithium cobalt oxide was prepared by mixing a predetermined amount of lithium carbonate and cobalt carbonate powder and then firing at 900 ° C. for 5 hours. Next, this was pulverized, and to 85 parts by weight of the obtained lithium cobalt oxide, 5 parts by weight of acetylene black, 10 parts by weight of the polymer obtained in Polymerization Example 3, and lithium bis (trifluoromethylsulfonyl)
After adding 5 parts by weight of imide (LiTFSI) and mixing with a roll, 30
It was pressed into a size of 10 mm x 10 mm x 0.2 mm at a pressure of MPa to obtain a battery positive electrode.

The polymer solid electrolyte obtained in Example 3 was sandwiched between a lithium metal foil and a positive electrode plate so that the interface was adhered.
The charge / discharge characteristics of the battery were examined at 25 ° C. while applying a pressure of 1 MPa. The initial discharge voltage at the terminal voltage of 3.8 V is 0.1 mA /
cm ^2, and was chargeable at 0.1 mA / cm ^2. Since the battery of this embodiment can be easily made thin, the battery is lightweight and has a large capacity.

Example 7 A secondary battery was constructed by using the polymer solid electrolyte obtained in Example 4 as an electrolyte, a lithium metal foil as a negative electrode, and lithium cobalt oxide (LiCoO ₂ ) as a positive electrode active material. Polymer solid electrolyte size is 10 mm x 10 mm x 0.0
5 mm. Lithium foil size is 10 mm x 10 mm x
0.1 mm. Lithium cobalt oxide was prepared by mixing a predetermined amount of lithium carbonate and cobalt carbonate powder and then firing at 900 ° C. for 5 hours. Next, this was pulverized, and to 85 parts by weight of the obtained lithium cobalt oxide, 5 parts by weight of acetylene black, 10 parts by weight of the polymer obtained in Polymerization Example 3, and lithium bis (trifluoromethylsulfonyl)
After adding 5 parts by weight of imide (LiTFSI) and 5 parts by weight of the siloxane compound represented by the formula (17) and mixing with a roll, press molding was performed at a pressure of 30 MPa into a size of 10 mm x 10 mm x 0.2 mm to form a positive electrode of a battery. did.

The polymer solid electrolyte obtained in Example 4 was sandwiched between a lithium metal foil and a positive electrode plate so that the interface was adhered.
The charge / discharge characteristics of the battery were examined at 25 ° C. while applying a pressure of 1 MPa. The initial discharge voltage at the terminal voltage of 3.8 V is 0.1 mA /
cm ^2, and was chargeable at 0.1 mA / cm ^2. Since the battery of this embodiment can be easily made thin, the battery is lightweight and has a large capacity.

[0079]

The solid polymer electrolyte of the present invention is excellent in processability, moldability, mechanical strength, flexibility and heat resistance,
And the ionic conductivity is remarkably improved. Therefore, it is expected to be applied to large-capacity capacitors and display devices such as solid-state batteries (particularly secondary batteries), electronic devices such as electrochromic displays, and antistatic agents or antistatic materials for rubber and plastic materials. To be done.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01G 9/032 H01M 6/22 C H01M 6/18 10/40 B 6/22 H01G 9/00 301G 10 / 40 9/02 321 (72) Inventor Seiji Nakamura 1-10-8 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Daiso Co., Ltd. (72) Inventor Yoshihiko Wada 1-10-8 Edobori, Nishi-ku, Osaka City, Osaka Daiso Corporation the internal F-term (reference) 4J005 AA04 AA09 BA00 4J035 BA02 CA03M CA031 CA13U CA131 GA08 GB05 LA05 LB20 5G301 CA30 CD01 5H024 AA01 AA02 AA09 AA11 AA12 FF21 FF23 FF31 HH00 HH02 5H029 AJ06 AJ11 AJ14 AK02 AK03 AK16 AL06 AL07 AL12 AM07 AM16 DJ09 EJ04 EJ12 HJ02 HJ11

Claims (6)

[Claims] 1. A polymer having an ether bond which may have a crosslinkable functional group, (2) an additive containing an organosilicon compound having an ethylene oxide unit, and (3) an electrolyte salt compound. An electrolyte composition comprising: a polymer (1) having an ether bond, (1-1) a structural unit represented by the following formula (i) and a structural unit represented by the following formula (ii) And / or (1-2) a structural unit (i), a structural unit (ii), and a crosslinkable structural unit represented by the following formula (iii). An additive (2) which is a copolymer and contains an organosilicon compound having an ethylene oxide unit is represented by the following formulas (iv), (v) and (v)
An electrolyte composition selected from the group consisting of organosilicon compounds having an ethylene oxide unit represented by i). [Chemical 1] [Chemical 2] [In the formula, R ¹ is an alkyl group or -CH ₂ -O-(-CH ₂ -CH _{2-
O-) n} -CH ₃ or _{-CH 2 -O-CH [(-} CH 2 -CH 2 -O-) n -CH 3]
Represents ₂ , and n is an integer of 0-12. ] [Chemical 3] [In the formula, R ² represents a functional group having a reactive functional group. ] [Chemical 4] ^{Wherein, A 11, A 12, A} 13 and ^{A 14} may be different from each _{other, - (- CH 2) p} - ( where, p is an integer of 0 to 3.)
X < ¹¹ >, X < ¹² >, X <^13> and X < ¹⁴ > may be different and each represent a methyl group, an ethyl group, a propyl group or a butyl group, and a, b, c and d are integers of 1 to 50. ] [Chemical 5] [In the formula, A ²¹ , A ²² and A ²³ may be different from each other, and represent-(-CH ₂ ) _p- (where p is an integer of 0 to 3),
X ²¹ , X ²² , X ²³ and X ²⁴ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, and h, i and j are integers of 1 to 50. ] [Chemical 6] [In the formula, A ³¹ and A ³² may be different from each other, and-(-C
H ₂ ) _p − (where p is an integer of 0 to 3), and X ³¹ , X
³² , X ³³ , X ³⁴ , X ³⁵ and X ³⁶ may be different from each other and represent a methyl group, an ethyl group, a propyl group or a butyl group, s and u are integers of 1 to 50, and t is 0 to 10
For t <s and t <u. ] 2. The reactive functional group in the crosslinkable structural unit is (a) a reactive silicon group, (b) a methylepoxy group, (c) an ethylenically unsaturated group or (d) a halogen atom. The electrolyte composition according to 1. 3. The electrolyte composition according to claim 1, wherein the polymer (1) having an ether bond has a weight average molecular weight of 10 ⁵ to 10 ⁷ . 4. The electrolyte composition according to claim 1, wherein the electrolyte salt compound is a lithium salt compound. 5. An electrolyte composition containing a crosslinked polymer obtained by crosslinking a copolymer by utilizing the reactivity of the crosslinkable structural unit in the polymer (1) according to any one of claims 1 to 3. 6. A battery comprising the electrolyte composition according to claim 1 and a positive electrode and a negative electrode.