JP2003257239A - Cross-linked polymer solid electrolyte and battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cross-linked polymer solid electrolyte that is superior in mechanical property and ion conduction. <P>SOLUTION: This is a cross-linked polymer solid electrolyte that is obtained from (A) a siloxane compound having two or more functional groups capable of cross-linking, (B) a polymer having ether linkage containing a functional group capable of cross-linking, (C) an electrolyte salt compound, and (D) a siloxane compound having one reactive group existing as necessary. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

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

[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 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, but the film strength of the electrolyte is increased. Therefore, when the polymer electrolyte is crosslinked, the mobility of molecules is reduced, resulting in a reduction in ionic conductivity. Practically sufficient conductivity values have not been obtained.

[0005]

An object of the present invention is to provide a crosslinked polymer solid electrolyte having excellent mechanical properties and ionic conductivity.

[0006]

The present invention provides (A) a siloxane compound having two or more crosslinkable functional groups, and (B)
A polymer having an ether bond containing a crosslinkable functional group,
A crosslinked polymer solid electrolyte obtained from (C) an electrolyte salt compound and (D) a siloxane compound having one reactive group, which is optionally present. Furthermore, the present invention also provides a battery using the crosslinked polymer solid electrolyte.

The crosslinked polymer solid electrolyte is a plasticizer, especially
When a plasticizer containing an organosilicon having an ethylene oxide unit (oxyethylene chain) is contained, crystallization of the polymer is suppressed, the glass transition temperature is lowered, and many amorphous phases are formed even at low temperatures, resulting in good ionic conductivity. Become. It was also found that a high-performance battery having a small internal resistance can be obtained by using the crosslinked polymer solid electrolyte of the present invention. The crosslinked polymer solid electrolyte of the present invention may be in the form of gel. Here, the gel is a polymer swollen by a solvent such as an aprotic organic solvent.

The siloxane compound (A) having two or more crosslinkable functional groups is preferably a siloxane compound having at least two crosslinkable functional groups and at least one oxyethylene chain. The reactive group in the crosslinkable functional group is generally (a) an ethylenically unsaturated group, (b) a silicon hydride group, (c) an epoxy group or (d) a hydroxyl group. It is preferably an ethylenically unsaturated group.

The siloxane compound (A) is particularly preferably a compound represented by the following formula (A-1), (A-2) or (A-3).

[0010]

[Chemical 9] [Wherein R ³ and R ⁶ are CH ₂ = CCH ₃ CO ₂ -or CH ₂ = CH
CO ₂ -or an alkenyloxy group having 2 to 5 carbon atoms, R ⁴ and R ⁵ are each-(CH ₂ ) _p- or-(CH ₂ ) _q- (where p and q are 0
~ Integer of 3), a, b and c are integers of 0 to 50. ]

[0011]

[Chemical 10] [Wherein R ⁷ and R ¹⁰ are CH ₂ ═CCH ₃ CO ₂ C ₃ H ₆ — or CH ₂ ═CHCO ₂ C ₃ H ₆ — or an alkenyl group having 2 to 5 carbon atoms, and R ⁸ and R ⁹ are each - (CH _{2) r} - or - (CH _{2) s} - (where, r, s is an integer of 0 to 3) represents a, the d and e and f 0 to 2
Indicates an integer of 5. ]

[0012]

[Chemical 11] [Wherein R ¹¹ is CH ₂ = CCH ₃ CO ₂ C ₃ H ₆ -or CH ₂
= CHCO ₂ C ₃ H ₆ -or an alkenyl group having 2 to 5 carbon atoms, R
¹³ is CH ₂ = CCH ₃ CO ₂ -or CH ₂ = CHCO ₂ -or an alkenyloxy group having 2 to 5 carbon atoms, and R ¹² is-(CH ₂ ) _t-.
(However, t is an integer of 0 to 3) and g and h are integers of 0 to 25. ]

The polymer (B) having an ether bond may generally be a polymer having an oxyethylene chain in the main chain and a reactive group in the side chain. In the polymer (B),
The reactive group is (a) an ethylenically unsaturated group, (b) a methylepoxy group, or (c) a halogen atom. The reactive group is preferably an ethylenically unsaturated group. The polymer (B) is
It may be a copolymer produced from at least two monomers. The polymer (B) is generally a copolymer obtained by polymerizing an ethylene oxide monomer and an oxirane compound monomer having a reactive group.

The polymer (B) is represented by the constitutional unit represented by the following formula (B-1), the constitutional unit represented by the following formula (B-2) and the following formula (B-3). It is preferably a copolymer containing a crosslinkable structural unit.

[0015]

[Chemical 12]

[Chemical 13] [Wherein R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, particularly 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, n is 0
It is an integer of 12. ]

[0016]

[Chemical 14] [In the formula, R ² represents a functional group having a reactive group. ]

The structural unit (B-1) is formed of ethylene oxide. Examples of the oxirane compound forming the structural unit (B-2) include 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 structural unit (B-3) can be formed by an oxirane compound having a reactive group selected from (a) an ethylenically unsaturated group, (b) a methylepoxy group, or (c) a halogen atom.

(A) The oxirane compound having an ethylenically unsaturated group 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. Preferably,
Examples include allyl glycidyl ether, glycidyl acrylate, and glycidyl methacrylate.

(B) The oxirane compound having a methylepoxy group includes 2,3-epoxypropyl-2 ', 3'-epoxy-2'.
-Methylpropyl ether, and ethylene glycol-2,
3-epoxypropyl-2 ', 3'-epoxy-2'-methylpropyl ether may be mentioned.

In the oxirane compound having a halogen atom (c), examples of the monomer having a halogen atom are epibromohydrin, epiiodohydrin and epichlorohydrin.

The polymerization method of a copolymer having an ether bond is a polymerization method of obtaining a copolymer by a ring-opening reaction of an ethylene oxide moiety, and is disclosed in Japanese Patent Application Laid-Open No. 63-1547 of the present applicant.
It is carried out in the same manner as the method described in JP-A No. 36 and JP-A-62-169823.

The crosslinked polymer solid electrolyte of the present invention may contain a siloxane compound (D) having one reactive group. The siloxane compound (D) having one reactive group is
A siloxane compound having a reactive group and an oxyethylene chain is preferable. Examples of reactive groups are ethylenically unsaturated groups, silicon hydride groups, epoxy groups and hydroxyl groups.
The reactive group is preferably an ethylenically unsaturated group.
The siloxane compound (D) is particularly preferably the following formula (D
-1) or a compound represented by (D-2).

[0024]

[Chemical 15] [Wherein R ¹⁴ is CH ₂ = CCH ₃ CO ₂ C ₃ H ₆ -or CH ₂ = CHC
O ₂ C ₃ H ₆ -or an alkenyl group having 2 to 5 carbon atoms, R ¹⁶ is an alkyl group having 1 to 3 carbon atoms, R ¹⁵ is-(CH ₂ ) _u- (where u is
(Integer of 0 to 3), i and j represent an integer of 0 to 50. ]

[0025]

[Chemical 16] [Wherein R ¹⁷ is CH ₂ ═CCH ₃ CO ₂ — or CH ₂ ═CHCO ₂ — or an alkenyloxy group having 2 to 5 carbon atoms, and R ¹⁸ is — (CH ₂ ).
v- (however, v is an integer of 0 to 3) and k and m are integers of 0 to 50. ]

The amount of the siloxane compound (A) having two or more crosslinkable functional groups is 0.1 to 50 parts by weight, for example 1 to 30 parts by weight, based on 100 parts by weight of the polymer (B).
It may especially be 5 to 25 parts by weight. May be The amount of the siloxane compound (D) having one reactive group used as necessary is 0.1 to 50 parts by weight, for example 1 to 30 parts by weight, based on 100 parts by weight of the polymer (B). , In particular 5 to 25 parts by weight.

The polymerization reaction for obtaining the polymer (B) having an ether bond can be carried out as follows. Using a catalyst system mainly composed of organoaluminum as a catalyst for ring-opening polymerization, a catalyst system mainly composed of organozinc, an organotin-phosphoric acid ester condensate catalyst system, etc., in the presence or absence of a solvent for a monomer, A polyether polymer 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 in terms of the degree of polymerization or the properties of the polypolymer to be produced. The reactive group does not react in the polymerization reaction, and a polymer having a reactive group is obtained.

When the polymer (B) is composed of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3), the amount of ethylene oxide forming the structural unit (B-1). Is 5 to 90% by weight, preferably 10 to 90% by weight of the polymer (B), and the amount of the oxirane compound forming the structural unit (B-2) is 90 to 5% by weight of the polymer (B), preferably 90-10
The amount of the oxirane compound forming the structural unit (B-3) is 1 to 30% by weight, preferably 3 to 20% by weight of the polymer (B).
% By weight.

When the proportion of the crosslinkable oxirane compound forming the structural unit (B-3) is 30% by weight or less, the crosslinked polymer has good ionic conductivity.
When the proportion of ethylene oxide forming the structural unit (B-1) is 5% 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 crosslinked polymer solid electrolyte of the present invention has a remarkably large effect of improving the ionic conductivity.

The polymer (B) used in the crosslinked polymer solid electrolyte has a weight average molecular weight of 10 ⁴ to 10 ^{7 in} order to obtain good processability, moldability, mechanical strength and flexibility.
Those within the range of 10 ⁵ to 10 ⁶ , preferably within the range of 10 ⁵ to 10 ⁶ are suitable.

A siloxane compound (A) whose crosslinkable functional group is an ethylenically unsaturated group, a polymer (B) whose crosslinkable functional group is an ethylenically unsaturated group, and an ethylenically unsaturated reactive group As the crosslinking method in the case of the siloxane compound (D) which is a group, 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.

Examples of the organic peroxide 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 addition amount of the organic peroxide varies depending on the type of the organic peroxide, but is usually the components (A), (B), (C) and (D).
In the range of 0.1 to 10 parts by weight with respect to 100 parts by weight in total.

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 addition amount of the azo compound varies depending on the kind of the azo compound, but is usually within the range of 0.1 to 10 parts by weight based on 100 parts by weight of the total of the components (A), (B), (C) and (D). is there.

In crosslinking by irradiation with active energy rays such as ultraviolet rays, acetophenones such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and phenylketone as sensitization aids, benzoin, Benzoin ethers such as benzoin methyl ether, benzophenone, benzophenones such as 4-phenylbenzophenone, 2-isopropylthioxanthone, 2,4-
Thioxanthones such as dimethylthioxanthone and azides such as 3-sulfonylazidobenzoic acid and 4-sulfonylazidobenzoic acid can be optionally used.

When the siloxane compound (A) in which the crosslinkable functional group is a silicon hydride group and the polymer (B) in which the crosslinkable functional group is an ethylenically unsaturated group are: A hydrosilylation reaction is used.

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.

When the polymer (B) in which the crosslinkable functional group is a methylepoxy group and the siloxane compound (A) in which the crosslinkable functional group is an epoxy group are used, crosslinking methods include polyamines and acids. Anhydrides and the like are used.

Examples of 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 the sum of components (A), (B), (C) and (D).
It is in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight.

Examples of the acid anhydrides include maleic anhydride, phthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrophthalic anhydride and the like. The addition amount of the acid anhydrides varies depending on the type of the acid anhydride, but is usually components (A), (B) and (D).
In the range of 0.1 to 10 parts by weight based on 100 parts by weight in total. 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 in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the crosslinking agent.

When the siloxane compound (A) in which the crosslinkable functional group is a hydroxyl group and the polymer (B) in which the crosslinkable functional group is a halogen atom-containing group are used, the crosslinking method is metallic sodium or hydrogen. Sodium chloride or the like is used. Further, it is effective from the viewpoint of the thermal stability of the halogen-containing polymer that the crosslinked polymer solid electrolyte further contains a metal compound serving as an acid acceptor. Examples of the metal oxide serving as such an acid acceptor include magnesia, magnesium hydroxide, magnesium carbonate, calcium silicate, calcium stearate, red lead, and tin stearate. The amount of the metal compound serving as the acid-accepting agent varies depending on the type, but usually the components (A), (B),
0.1 to 100 parts by weight of the total of (C) and (D)
~ 30 parts by weight.

The electrolyte salt compound (C) used in the present invention is a polyether polymer or a crosslinked product of the polymer.
It is preferably soluble in a mixture of and a plasticizer. 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 ⁻, PF₆
⁻, Stearyl sulfonate ion, octyl sulfonate
Ion, dodecylbenzene sulfonate ion, naphthale
Sulfonate ion, dodecylnaphthalene sulfonate a
On, 7,7,8,8-tetracyano-p-quinodimethane ion,
X¹SO_Three ⁻, [(X¹SO_Two) (X^TwoSO_Two) N]⁻, [(X¹SO_Two) (X^Two
SO_Two) (X^ThreeSO_Two) C] ⁻, And [(X¹SO_Two) (X^TwoSO_Two) YC]⁻ 
And an anion selected from
However, X¹, X^Two, X^ThreeAnd Y are electron withdrawing groups. Preferred
X¹, X^Two, And X^ThreeEach independently has 1 carbon
To 6 perfluoroalkyl groups or 6 to 1 carbon atoms
3 is a perfluoroaryl group, Y is a nitro group, and
Troso group, carbonyl group, carboxyl group or cyano group
Is. X¹, X^TwoAnd X^ThreeAre the same, but different
You may As the metal cation, the transition metal cation
You can use on. Preferably Mn, Fe, Co, Ni, Cu,
The cations of metals selected from Zn and Ag metals are used.
Be done. Also, selected from Li, Na, K, Rb, Cs, Mg, Ca and Ba metals.
Preferred results are also obtained with different metal cations.
Use two or more of the above compounds together as electrolyte salt compounds
You are free to do anything.

In the present invention, the amount of the electrolyte salt compound (C) used is 1 to 10 with respect to 100 parts by weight of the polymer (B).
The range is 0 parts by weight, preferably 10 to 80 parts by weight. When the amount of the electrolyte salt compound (C) is less than 100 parts by weight, workability, moldability and mechanical strength and flexibility of the obtained solid electrolyte are good, and further, ion conductivity is also good.

In the present invention, in order to further improve the ionic conductivity, the (E) plasticizer may be blended and the electrolyte may be used in the form of gel. The plasticizer (E) is preferably an aprotic organic solvent and a compound having an ethylene oxide unit (oxyethylene chain).

As the aprotic organic solvent used in the present invention, aprotic ethers and esters are used. Specifically, propylene carbonate, γ
-Butyrolactone, butylene carbonate, ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, 1,2-dimethoxyethane, 1,2-dimethoxypropane, 3-methyl-2-oxazolidone, tetrahydrofuran, 2-methyltetrahydrofuran, 1 , 3-Dioxolane, 4,4-methyl-1,3-dioxolane, tert-butyl ether, iso-butyl ether, 1,2-
Examples include ethoxymethoxyethane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether. Even if a mixture of two or more of these is used, good. Particularly preferred are propylene carbonate, γ-butyrolactone, butylene carbonate and 3-methyl-2-oxazoline.

As the compound having an ethylene oxide unit, an ether compound and an organic silicon compound are used. Specifically, the ether compound having an ethylene oxide unit is triethylene glycol dimethyl ether,
Examples thereof include triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, oligoethylene glycol dimethyl ether, and the like.

Examples of the organosilicon compound having an ethylene oxide unit include those represented by the following formulas (i), (ii) and (iii).

[0048]

[Chemical 17] [In the formula, A ¹¹ , A ¹² , A ¹³ and A ¹⁴ may be different from each other, and represent-(-CH ₂ ) _p- (where P is an integer of 0 to 3);
¹¹ , X ¹² , X ¹³ and X ¹⁴ may each be different,
Represents a methyl or ethyl group, p1, q1, r1 and s1
Is an integer from 1 to 50. ]

[0049]

[Chemical 18] [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 each be different,
Represents a methyl or ethyl group, where t1, u1 and v1 are 1
It is an integer from ~ 50. ]

[0050]

[Chemical 19] [In the formula, A ³¹ and A ³² may be different from each other, and-(-CH
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 each be different,
Represents a methyl group or an ethyl group, w1 and y1 are integers of 1 to 50, x1 <w1 and x1 <y1. ]

The mixing ratio of the plasticizer (E) is optional,
The amount is 5 to 2,000 parts by weight, preferably 20 to 1,000 parts by weight, based on 100 parts by weight of the polymer (B).

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

The method for producing the crosslinked polymer solid electrolyte of the present invention is not particularly limited, but usually the respective components may be mechanically mixed. In the case of a polymer requiring cross-linking, it is produced by a method in which all components are mixed and then cross-linked by activating energy rays of heat or ultraviolet rays, but after the cross-linking, it is immersed in a plasticizer for a long time. You may impregnate it. As a means for mechanically mixing, a stirrer or other stirrer, a kneader, an open roll, an extruder or the like can be arbitrarily used.

When the reactive 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 group is an ethylenically unsaturated group and a radical initiator is used, the crosslinking reaction is completed in 1 minute to 20 hours under the temperature condition of 10 ° C. to 200 ° C. Further, when utilizing energy rays such as ultraviolet rays, a sensitizer is generally used. Normally, 0.1 seconds to 10 ℃ to 150 ℃
The crosslinking reaction is completed in 1 hour. With a crosslinking agent containing silicon hydride, the crosslinking reaction is completed within 10 minutes to 10 hours under the temperature condition of 10 ° C to 180 ° C.

Electrolyte salt compounds and additives (ie siloxane compounds (A) and (C) and plasticizers (E))
Is not particularly limited, but a method of immersing the polyether polymer in an organic solvent containing an electrolyte salt compound and an additive for a long time to impregnate the electrolyte salt compound and the additive with the polyether polymer Mechanical mixing method, a method in which a polyether polymer and an electrolyte salt compound are dissolved in an additive and mixed, or a method in which the polyether polymer is once dissolved in another organic solvent and then the additive is mixed. . When manufacturing using an organic solvent, various polar solvents such as tetrahydrofuran, acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, methyl isobutyl ketone, etc. may be used alone or in combination.

The crosslinked polymer solid electrolyte of the present invention is excellent in mechanical strength and flexibility, and it is easy to obtain a solid electrolyte in the form of a large-area thin film by utilizing its properties. For example, it is possible to manufacture a battery using the crosslinked polymer solid electrolyte 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. It is also possible to use cations such as alkali metal ions, Cu ions, Ca ions, and Mg ions as diaphragms of ion electrodes by utilizing their high electrical conductivity.
The crosslinked polymer solid electrolyte of the present invention is particularly suitable as a material for electrochemical devices such as batteries, capacitors and sensors.

The polymer electrolyte can be used in primary batteries or secondary batteries, for example lithium secondary batteries. The thickness of the polymer electrolyte in the battery is not particularly limited, but may be, for example, 2 μm to 2 mm.

[0059]

EXAMPLES The present invention will be described in detail below with reference to examples. The monomer equivalent composition of the polyether copolymer is ¹ H
It was determined by 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 performed by Shimadzu Corporation RID-10A, Showa Denko KK column Showdex KD-807, KD-806, KD-8
Performed at 60 ° C. using 06M and KD-803, and the solvent dimethylformamide. Glass transition temperature and heat of fusion are Rigaku Denki
The measurement was performed using a differential scanning calorimeter DSC 8230B manufactured by Co., Ltd. in a nitrogen atmosphere at a temperature range of -100 to 80 ° C and a temperature rising rate of 10 ° C / min. In order to measure the ionic conductivity σ, the sample film was vacuum dried in advance at 30 ° C for 12 hours. The ionic conductivity was measured at 10 ° C., the film was sandwiched between SUS electrodes, and calculated by the complex impedance method using an AC method with a voltage of 0.5 V and a frequency range of 5 Hz to 1 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 heated at 250 ° C. for 20 minutes while stirring under a nitrogen stream. The distillate was distilled off to obtain a solid condensed substance as a residue. Thereafter, this was used as a polymerization catalyst.

Polymerization Example 1 (Production of Copolymer Having Ether Bond Containing Crosslinkable Functional Group) The inside of a glass 4-necked flask having an internal volume of 3 L was replaced with nitrogen, and a synthetic example (catalyst The following formula (1) adjusted to 2 g of the condensed substance obtained in
110 g of oxirane compound (EM) shown in 1), 18 g of glycidyl methacrylate and 1,000 g of n-hexane as a solvent.
90 g of ethylene oxide was sequentially added while the polymerization rate of EM was monitored by gas chromatography.
The polymerization reaction was stopped with methanol. After removing the polymer by decantation, it was dried at 40 ° C under normal pressure for 24 hours and then under reduced pressure at 45 ° C for 10 hours to obtain 200 g of polymer.
Got 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
The results of monomer-based composition analysis of this polymer by NMR spectrum were ethylene oxide 43 wt%, EM 50 wt%, and glycidyl methacrylate 7 wt%.

[0062]

[Chemical 20]

Polymerization Example 2 (Production of a Copolymer Having an Ether Bond Containing a Crosslinkable Functional Group) The inside of a glass 4-necked flask having an internal volume of 3 L was replaced with nitrogen, and a synthetic example (catalyst 2 g of the condensed material obtained in (Production) and the following formula (1
100 g of the oxirane compound (GM) shown in 2), 10 g of allyl glycidyl ether and n-hexane as the solvent 1,
000 g was charged, and 120 g of ethylene oxide was sequentially added while the polymerization rate of GM was monitored by gas chromatography. The polymerization reaction was stopped with methanol. After removing the polymer by decantation, it is kept at 40 ° C under normal pressure for 24 hours.
205 g of polymer after drying for 10 hours at 45 ° C under reduced pressure
Got 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
The results of analysis of the monomer-converted composition of this polymer by NMR spectrum were ethylene oxide 53 wt%, GM 43 wt%, and allyl glycidyl ether 4 wt%.

[0064]

[Chemical 21]

Example 1 The polymer obtained in Polymerization Example 1 (ethylene oxide / EM /
Glycidyl methacrylate terpolymer) 1 g, siloxane compound 0.1 g having two crosslinkable functional groups represented by the following formula (13), siloxane compound having one reactive group represented by the following formula (14) 0.2 g, lithium bis (trifluoromethylsulfonyl) as a lithium salt compound
After mixing 0.6 g of imide (LiTFSI) and 0.015 g of benzoyl peroxide as a polymerization initiator in 50 g of acetonitrile until homogeneous, polyethylene terephthalate (PE
T) Coated on film. Then, it was dried under reduced pressure at 30 ° C. for 12 hours, and further heated at 100 ° C. for 2 hours in a nitrogen atmosphere to obtain a crosslinked film of 50 μm. The ionic conductivity was 4.2 x 10 ^-5 S / cm.

[0066]

[Chemical formula 22]

[Chemical formula 23]

Example 2 The polymer obtained in Polymerization Example 2 (ethylene oxide / GM /
Allyl glycidyl ether terpolymer) 1 g, formula (1
0.2 g of a siloxane compound having two crosslinkable functional groups shown in 3), 0.6 g of LiTFSI as a lithium salt compound,
As a polymerization initiator, 0.015 g of benzoyl peroxide was mixed in 50 g of acetonitrile until homogeneous, and then PET was used.
It was applied on a film. Then, it was dried under reduced pressure at 30 ° C. for 12 hours, and further heated at 100 ° C. for 2 hours in a nitrogen atmosphere to obtain a crosslinked film of 50 μm. Ionic conductivity is 3.
It was 1 × 10 ⁻⁵ S / cm.

Example 3 Ethylene oxide / propylene oxide / glycidyl methacrylate having a weight average molecular weight of 700,000 (= 60/32/8 wt%)
Ternary copolymer 1 g, siloxane compound 0.2 having two crosslinkable functional groups represented by the formula (13) in Example 2 0.2
g, a compound having an oxyethylene chain represented by the following formula (15) (plasticizer) 0.5 g, LiTFSI as a lithium salt compound
0.6 g and 0.015 g of benzoyl peroxide as a polymerization initiator were mixed in 50 g of acetonitrile until uniform, and then coated on a PET film. Then, at 30 ℃ 12
It was dried under reduced pressure for an hour and further heated at 100 ° C. for 2 hours in a nitrogen atmosphere to obtain a crosslinked film of 50 μm. The ionic conductivity was 1.2 x 10 ^-4 S / cm.

[0069]

[Chemical formula 24]

Example 4 A secondary battery was constructed using the polymer solid electrolyte obtained in Example 1 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 0.05 mm
Is. Lithium foil size is 10 mm x 10 mm x 0.1 m
m. 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 and 10 parts by weight of the polymer obtained in Polymerization Example 1,
After adding 5 parts by weight of LiTFSI and mixing with a roll, press molding was performed at a pressure of 3 MPa to 10 mm X 10 mm X 0.2 mm to obtain a battery positive electrode.

The polymer solid electrolyte obtained in Example 1 was sandwiched between a lithium metal foil and a positive electrode plate so that the interface was in close contact.
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 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 0.05 mm
Is. Lithium foil size is 10 mm x 10 mm x 0.1 m
m. 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) imide (LiTFSI) 5 were added. Add 3 parts by weight and roll to mix, then 3MP
It was pressed into a size of 10 mm X 10 mm X 0.2 mm at the pressure of a 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. Discharge current at initial 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 0.05 mm
Is. Lithium foil size is 10 mm x 10 mm x 0.1 m
m. 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 and 10 parts by weight of the polymer obtained in Polymerization Example 2,
Lithium bis (trifluoromethylsulfonyl) imide
5 parts by weight of (LiTFSI) and 5 parts by weight of the siloxane compound represented by the formula (15) were added and mixed with a roll, and then press-molded at a pressure of 3 MPa to 10 mm X 10 mm X 0.2 mm 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 in close contact.
The charge / discharge characteristics of the battery were examined at 25 ° C while applying a pressure of 1 MPa. Discharge current at initial 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.

[0076]

The crosslinked polymer solid electrolyte of the present invention is excellent in workability, moldability, mechanical strength, flexibility and heat resistance, and its 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.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masato Tabuchi             1-10-8 Edobori, Nishi-ku, Osaka City, Osaka Prefecture             Within Daiso Corporation (72) Inventor Satoshi Murakami             1-10-8 Edobori, Nishi-ku, Osaka City, Osaka Prefecture             Within Daiso Corporation F-term (reference) 4J002 CH02X CP12W CP123 CP18W                       CP183 DD006 DD026 DG016                       DK006 EV236 FD206 GQ02                 5G301 CA08 CA16 CA30 CD01                 5H029 AJ01 AK03 AL12 AM12 AM16                       HJ20

Claims (8)

[Claims] 1. A siloxane compound having two or more crosslinkable functional groups, (B) a polymer having an ether bond containing a crosslinkable functional group, (C) an electrolyte salt compound, and (D) necessary. A crosslinked solid polymer electrolyte obtained from a siloxane compound having one reactive group, which is present according to the above. 2. The siloxane compound (A) having two or more crosslinkable functional groups is represented by the following formulas (A-1) and (A-
The compound represented by 2) or (A-3).
The crosslinked polymer solid electrolyte described. [Chemical 1] [Wherein R ³ and R ⁶ are CH ₂ = CCH ₃ CO ₂ -or CH ₂ = CH
CO ₂ -or an alkenyloxy group having 2 to 5 carbon atoms, R ⁴ and R ⁵ are each-(CH ₂ ) _p- or-(CH ₂ ) _q- (where p and q are
An integer of 0 to 3), and a, b and c are integers of 0 to 50. ] [Chemical 2] [Wherein R ⁷ and R ¹⁰ are CH ₂ ═CCH ₃ CO ₂ C ₃ H ₆ — or CH ₂ ═CHCO ₂ C ₃ H ₆ — or an alkenyl group having 2 to 5 carbon atoms, and R ⁸ and R ⁹ are each - (CH _{2) r} - or - (CH _{2) s} - (where, r, s is an integer of 0 to 3) represents a, the d and e and f 0 to 2
Indicates an integer of 5. ] [Chemical 3] [Wherein R ¹¹ is CH ₂ = CCH ₃ CO ₂ C ₃ H ₆ -or CH ₂ = CHC
O ₂ C ₃ H ₆ -or an alkenyl group having 2 to 5 carbon atoms, R ¹³ is C
H _{2 =} CCH ₃ CO _{2 -} or CH _{2 =} CHCO _{2 -} or alkenyloxy group having 2 to 5 carbon atoms, R ¹² is - (CH _{2) t} - (where, t is 0 to 3
Is an integer) and g and h are integers from 0 to 25. ] 3. The polymer (B) has the following formula (B-1):
The copolymer containing the structural unit represented by, the structural unit represented by the following formula (B-2), and the crosslinkable structural unit represented by the following formula (B-3). Crosslinked polymer solid electrolyte. [Chemical 4] [Chemical 5] [Wherein R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, particularly 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, n is 0
It is an integer of 12. ] [Chemical 6] [In the formula, R ² represents a functional group having a reactive group. ] 4. The siloxane compound (D) having one reactive group has the formula (D-1) or the formula (D-).
The crosslinked polymer solid electrolyte according to claim 1, which is a compound represented by 2). [Chemical 7] [Wherein R ¹⁴ is CH ₂ = CCH ₃ CO ₂ C ₃ H ₆ -or CH ₂ = CHC
O ₂ C ₃ H ₆ -or an alkenyl group having 2 to 5 carbon atoms, R ¹⁶ is an alkyl group having 1 to 3 carbon atoms, R ¹⁵ is-(CH ₂ ) _u- (where u is
(Integer of 0 to 3), i and j represent an integer of 0 to 50. ] [Chemical 8] [Wherein R ¹⁷ is CH ₂ ═CCH ₃ CO ₂ — or CH ₂ ═CHCO ₂ — or an alkenyloxy group having 2 to 5 carbon atoms, and R ¹⁸ is — (CH ₂ ).
_v- (however, v is an integer of 0-3), k and m show the integer of 0-50. ] 5. The polymer (B) having an ether bond is a heavy polymer.
Weight average molecular weight is 10 ^Four~Ten⁷Claim 1 or claim
Item 3. The crosslinked polymer solid electrolyte according to Item 2. 6. A crosslinked polymer solid electrolyte further comprising (E) an aprotic organic solvent and a plasticizer selected from the group consisting of compounds having an oxyethylene chain. 7. The crosslinked polymer solid electrolyte according to claim 1, wherein the electrolyte salt compound is a lithium salt compound. 8. A battery comprising the crosslinked polymer solid electrolyte according to claim 1, a positive electrode and a negative electrode.