JP6112288B2 - Hyperbranched polymer having ethylene oxide chain and use thereof - Google Patents

Description

The present invention relates to a hyperbranched polymer having an ethylene oxide chain and use thereof.

  Solid electrolytes are expected as next-generation electrolytes used in secondary batteries. In particular, since a solvent-free polymer solid electrolyte in which polyethylene oxide (PEO) and a lithium salt are combined has been reported, research on polymer solid electrolytes has been actively conducted.

Excellent ion conductivity is indispensable for the electrolyte of the secondary battery. In general, the ionic conductivity of a polymer decreases below its glass transition temperature. This is presumed to be because the local motion (segment motion) of the polymer chain, which contributes to the improvement of ionic conductivity, decreases. In particular, linear PEO which is a crystalline polymer can be expected to have excellent ion conductivity when used as a matrix polymer, but is easily crystallized. Therefore, in a solid electrolyte using linear PEO, the ionic conductivity tends to be remarkably lowered near room temperature.

With regard to this problem, it is said that, for example, by using chemical crosslinking between PEOs or using PEO with a short chain length, the crystallization temperature of the polymer can be lowered and the ionic conductivity at room temperature can be improved. (Non-Patent Document 1). However, even with such a technique, there are cases where sufficient physical strength of the electrolyte cannot be ensured or the electrolyte cannot be solidified, and a solid electrolyte with a balance between physical strength and ionic conductivity is still strongly desired. It is rare.

In this regard, hyperbranched polymers that are amorphous substances are known to have free molecular chains with excellent segment mobility, and development of new solid electrolytes using these is being studied. Hyperbranched polymers are broadly classified into dendrimers and hyperbranched polymers. So far, it has been reported that excellent ion conductivity can be realized by using dendrimers having an ethylene oxide skeleton (Patent Documents 1 to 3). 4, Non-Patent Document 2).

On the other hand, comparing the dendrimer and the hyperbranched polymer, it is known that the hyperbranched polymer can be synthesized by a relatively simple method (Patent Document 5, Non-Patent Documents 3 and 4). It is advantageous in that point. However, although there are such advantages, it is difficult to produce a solid electrolyte with a hyperbranched polymer alone for reasons such as poor film formability. Therefore, for a solid electrolyte using a hyperbranched polymer, However, it was only considered as a mixed polymer solid electrolyte with linear PEO, and it was difficult to say that the performance was sufficiently obtained (Patent Documents 6 to 8).

JP 2003-327687 A JP 2004-124051 A Japanese Patent Laid-Open No. 2005-8802 JP 2009-1803 A International Publication No. 2010/137724 Pamphlet JP 2006-344504 A JP 2008-130529 A JP 2011-46784 A

Secondary battery materials This 10 years and future, issued May 30, 2003, pp. 174-175 Supervision by Akira Yoshino, CM Publishing Journal of the Electrochemical Society, 156 (7), pp. A577-A583, 2009 Macromolecules, Vol. 35, no. 9, pp. 3781-3784, 2002 Macromolecules, Vol. 36, no. 10, pp. 3505-3510, 2003

The present invention has been made in view of the above circumstances, and by mixing with a lithium salt, a solid electrolyte having excellent physical strength and excellent ionic conductivity can be produced. In particular, a lithium salt is used as the electrolyte. An object of the present invention is to provide a hyperbranched polymer suitable as a matrix polymer, which can contribute to the performance enhancement of the battery such as miniaturization and long life by being applied to the solid electrolyte of the secondary battery.

As a result of intensive studies in order to achieve the above object, the present inventors have found that the number of repetitions of a highly branched polymer site composed of a styrene unit and an ethylene oxide unit (—OCH ₂ CH ₂ —) in the molecule is 1 to ₂ . A hyperbranched spherical polymer having 40 polyether moieties exhibits excellent compatibility with a lithium salt required for a matrix polymer of a solid electrolyte using a lithium salt as an electrolyte. The present inventors have found that the solid electrolyte obtained by removing the solvent from the salt-containing solution exhibits excellent physical strength and excellent ionic conductivity so that a self-supporting membrane can be obtained.
In the present invention, “compatibility” refers to an affinity that can maintain a uniform solid without separation even when the solvent is removed from the solution containing the lithium salt covering the polymer. The “matrix polymer” is a polymer support in the polymer solid electrolyte, which imparts mechanical properties to the polymer solid electrolyte as the polymer support, dissociates the encapsulated lithium salt, It is a polymer compound that can play a role such as improving the mobility of ion species.

That is, the present invention
1. Formula (1)

{Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² and R ^{2 ′} each independently represent an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, or 3 carbon atoms. A cycloalkyl group having 20 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. A heteroaromatic group of (these alkyl group, haloalkyl group, cycloalkyl group, bicycloalkyl group, alkenyl group, alkynyl group, aromatic group and heteroaromatic group may be substituted with Z), A ¹ is the formula (2)

[Wherein, A ² represents an alkylene group having 1 to 20 carbon atoms (which may be substituted with Z and may include an ether group or an ester group), and Y ^{1 to} Y ⁴ each independently represent , Hydrogen atom, halogen atom, nitro group, cyano group, amino group, hydroxyl group, thiol group, phosphoric acid group, sulfonic acid group, carboxyl group, alkyl group having 1 to 20 carbon atoms, haloalkyl group having 1 to 20 carbon atoms , A cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms, or carbon The heteroaromatic group of number 2-20 is shown. Z represents a halogen atom, a nitro group, a cyano group, an amino group, a hydroxyl group, a thiol group, a phosphoric acid group, a sulfonic acid group, a carboxyl group, or an alkoxy having 1 to 20 carbon atoms. Group, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, An alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 1 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms or a heteroaromatic group having 2 to 20 carbon atoms; l shows the integer of 2-100,000, n and m show the integer of 1-40 each independently. } Hyperbranched polymer represented by
2. One hyperbranched polymer in which n and m are each independently 2 to 7;
3. 1 or 2 hyperbranched polymers in which Y ^{1 to} Y ⁴ are each independently a hydrogen atom, a methyl group or a methoxy group, and the A ² is a methylene group, an ethylene group or an n-propylene group,
4). The hyperbranched polymer according to any one of 1 to 3, wherein R ² and R ^{2 ′} are each independently a hydrogen atom, a methyl group or a phenyl group;
5. A matrix polymer comprising any one of the hyperbranched polymers of 1-4,
6). A solid electrolyte comprising a matrix polymer of 5;
7). 6 solid electrolyte containing lithium salt;
8). 7. The solid electrolyte according to 7, wherein the lithium salt is at least one selected from lithium sulfonic acid imide salt, lithium organic acid salt and lithium inorganic acid salt;
9. Any one of 5-8 solid electrolytes which are thin films,
A secondary battery having a solid electrolyte of any one of 10.5 to 9,
11. A composition comprising a hyperbranched polymer according to any one of 1 to 4 and a lithium salt,
12 11 compositions wherein the lithium salt is at least one selected from a lithium sulfonic acid imide salt, a lithium organic acid salt and a lithium inorganic acid salt;
13. 11 or 12 composition further comprising an organic solvent,
14 Any one of compositions 11 to 13 for solid electrolyte,
15. A method for producing a solid electrolyte, comprising removing a solvent from the composition of 13 or 14;
16. The method for producing a hyperbranched polymer according to 1, wherein the hyperbranched polymer represented by the formula (3) is reacted with the ethylene oxide represented by the formula (4) in the presence of an acid catalyst.

(Wherein R ¹ and A ¹ have the same meaning as above, l ′ has the same meaning as l, R ^{2 ″} has the same meaning as R ² and R ^{2 ′,} and X and X ′ represents a halogen atom, and k represents an integer of 1 to 40.)
I will provide a.

Since the hyperbranched polymer of the present invention exhibits high solubility in an organic solvent and high compatibility with a lithium salt, good physical strength can be obtained by removing the solvent from a solution in which the hyperbranched polymer is dissolved together with the lithium salt. A solid electrolyte having a low resistance value can be obtained by forming a thin film and forming a thin film by a wet process such as a spin coating method.
In addition, the hyperbranched polymer of the present invention is a mass-produced product that can be produced by a simpler method than a dendrimer (for example, a hyperbranch produced by Nissan Chemical Industries, Ltd.), although it has many branched structures like a dendrimer. (Tech (registered trademark) HPS-200) can be used as a raw material, and the like has advantages in production. Therefore, simplification of the manufacturing process of the solid electrolyte using the hyperbranched polymer as the matrix polymer and the associated cost reduction can be expected by using the hyperbrachi polymer of the present invention.

2 is a ¹ H-NMR spectrum of a hyperbranched polymer (Compound 1) obtained in Synthesis Example 1. 2 is a ¹ H-NMR spectrum of a hyperbranched polymer (Compound 2) obtained in Synthesis Example 2. 3 is a ¹ H-NMR spectrum of a hyperbranched polymer (Compound 3) obtained in Synthesis Example 3. 2 is a ¹ H-NMR spectrum of a hyperbranched polymer (Compound 4) obtained in Comparative Synthesis Example 1. It is an enlarged view of the ¹ H-NMR spectrum of FIG. 1-4 (described in order of Figures 1-4 from the bottom). 1 is a ¹ H-NMR spectrum of a hyperbranched polymer (Compound 4) obtained in Comparative Synthesis Example 1, a hyperbranched polymer (Compound 1) as a raw material, and a polyethylene glycol monomethyl ether (Me (PEG) OH1900) as a reactant ( From the bottom, compound 1, Me (PEG) OH1900, and compound 4 are listed in this order). FIG. 7 is an enlarged view of the ¹ H-NMR spectrum of FIG. 6.

Hereinafter, the present invention will be described in detail.
The hyperbranched polymer of the present invention is represented by the following formula (1).

In the formula (1), R ¹ represents a hydrogen atom or a methyl group.
In formula (1), R ² and R ^{2 ′} are each independently an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or 4 carbon atoms. A cycloalkyl group having 20 carbon atoms, an alkenyl group having 2-20 carbon atoms, an alkynyl group having 2-20 carbon atoms, an aromatic group having 6-20 carbon atoms, or a heteroaromatic group having 2-20 carbon atoms.

Specific examples of the alkyl group having 1 to 20 carbon atoms may be linear or branched. For example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, n-hexyl, n-decyl, Examples include n-pentadecyl, n-nonadecyl, and n-eicosyl group.

Examples of the haloalkyl group having 1 to 20 carbon atoms include those obtained by substituting at least one hydrogen atom of the alkyl group having 1 to 20 carbon atoms with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, A bromine atom, an iodine atom, etc. are mentioned.
Specific examples of the haloalkyl group include monofluoromethyl, difluoromethyl, trifluoromethyl, bromodifluoromethyl, 2-chloroethyl, 2-bromoethyl, 1,1-difluoroethyl, 2,2,2-trifluoroethyl, 1 , 1,2,2-tetrafluoroethyl, 2-chloro-1,1,2-trifluoroethyl, pentafluoroethyl, 3-bromopropyl, 1,1,1,3,3,3-hexafluoropropane- Examples include 2-yl and 3-bromo-2-methylpropyl groups.

  Specific examples of the cycloalkyl group having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and cycloundecyl groups.

  Specific examples of the bicycloalkyl group having 4 to 20 carbon atoms include bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl groups.

  Specific examples of the alkenyl group having 2 to 20 carbon atoms may be linear or branched, and include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl, n-1-butenyl, n- 2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1- Examples include pentenyl, n-1-decenyl, n-1-pentadecenyl, n-1-eicocenyl group, and the like.

  Specific examples of the alkynyl group having 2 to 20 carbon atoms may be linear or branched, and include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, Examples thereof include n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-1-hexynyl, n-1-decynyl, n-1-eicosinyl group and the like.

  Specific examples of the aromatic group having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4 -Phenanthryl, 9-phenanthryl group, etc. are mentioned.

  Specific examples of the heteroaromatic group having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-quinolyl and 3-quinolyl. Examples include quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl and the like.

Among these, considering the balance between the physical strength and ionic conductivity of the solid electrolyte obtained, R ² and R ^{2 ′} are preferably alkyl groups having 1 to 5 carbon atoms, and those having 1 to 3 carbon atoms. It is more preferably an alkyl group, and even more preferably a methyl group or an ethyl group.

  In addition, these alkyl groups, haloalkyl groups, cycloalkyl groups, bicycloalkyl groups, alkenyl groups, alkynyl groups, aromatic groups and heteroaromatic groups each have one or more hydrogen atoms as halogen atoms or nitro groups. , Cyano group, amino group, hydroxyl group, thiol group, phosphoric acid group, sulfonic acid group, carboxyl group, alkoxy group having 1 to 20 carbon atoms, thioalkoxy group having 1 to 20 carbon atoms, alkyl having 1 to 20 carbon atoms Group, haloalkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 20 carbon atoms, bicycloalkyl group having 4 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, carbon It may be substituted with a substituent Z of an acyl group having 1 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms or a heteroaromatic group having 2 to 20 carbon atoms.

As specific examples of the alkoxy group having 1 to 20 carbon atoms, the alkyl group therein may be linear, branched, or cyclic, and includes methoxy, ethoxy, n-propoxy, i-propoxy, c- Propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, c-butoxy, n-pentoxy, c-pentoxy, n-hexoxy, n-decyloxy, n-pentadecyloxy, n-nonadecyloxy, n- And an eicosyloxy group.

Specific examples of the thioalkoxy group having 1 to 20 carbon atoms (alkylthio group) include a group in which an oxygen atom in the alkoxy group is substituted with a sulfur atom.
Specific examples of the thioalkoxy group include methylthio, ethylthio, n-propylthio, i-propylthio, c-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, c-butylthio, n-pentylthio, Examples include c-pentylthio, n-hexylthio, n-decylthio, n-pentadecylthio, n-nanodecylthio, n-eicosylthio group and the like.

  Examples of the acyl group having 1 to 20 carbon atoms include formyl, acetyl, propionyl, butyryl, i-butyryl, valeryl, i-valeryl, pivaloyl, caproyl, enanthyl, caprylyl, pelargonyl, capryl group and the like.

  Other examples of the halogen atom, alkyl group, haloalkyl group, cycloalkyl group, bicycloalkyl group, alkenyl group, alkynyl group, aromatic group and heteroaromatic group are the same as those described above.

In the formula (1), A ¹ represents a divalent group represented by the following formula (2).

In the formula (2), A ² represents an alkylene group having 1 to 20 carbon atoms.
Specific examples of the alkylene group having 1 to 20 carbon atoms include, for example, methylene, ethylene, n-propylene (trimethylene), n-butylene (tetramethylene), n-pentylene (pentamethylene), n-decylene (decamethylene), Examples thereof include n-pentadecylene (pentacamethylene) and n-eicosylene (eicosamethylene) groups.
In the alkylene group having 1 to 20 carbon atoms, one or more hydrogen atoms may be substituted with a substituent Z, and an ether group or an ester group may be present between carbon atoms in the alkylene group. It may be included. Examples of the substituent Z include the same substituents as described above, and the number of ether groups or ester groups may be two or more.

In formula (2), Y ^{1 to} Y ⁴ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an amino group, a hydroxyl group, a thiol group, a phosphoric acid group, a sulfonic acid group, a carboxyl group, An alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and 2 carbon atoms -20 alkynyl group, a C6-C20 aromatic group, or a C2-C20 heteroaromatic group is shown.

Examples of such a halogen atom, alkyl group, haloalkyl group, cycloalkyl group, bicycloalkyl group, alkenyl group, alkynyl group, aromatic group and heteroaromatic group are the same as those described above.

Among these, considering the balance between physical strength and ionic conductivity of the obtained solid electrolyte, Y ^{1 to} Y ⁴ are preferably hydrogen atoms, methyl or ethyl groups, and are preferably hydrogen atoms or methyl groups. Is more preferable, and it is still more preferable that it is a hydrogen atom.

In formula (1), l is the number of repeating unit structures and represents an integer of 2 to 100,000. In particular, in view of improving the physical strength and ionic conductivity of the obtained solid electrolyte, l is preferably 5 to 10,000, and more preferably 20 to 500.
In addition, for example, when the hyperbranched polymer represented by the formula (3) is used as a synthesis raw material of the hyperbranched polymer represented by the formula (1), the hyperbranched polymer represented by the formula (1) is synthesized or purified. Unless special molecular weight fractionation operation is performed, l ′ in the formula (3), which is the number of repeating unit structures of the compound as a synthesis raw material, is assumed to be the same as l in the formula (1). The

In Formula (1), m and n are the number of repeating unit structures, show the integer of 1-40, and may be same or different.
In particular, in consideration of improving the physical strength and ionic conductivity of the solid electrolyte obtained, m and n are preferably 2 to 20, more preferably 3 to 10, and 7 to 8. Even more preferred.

The hyperbranched polymer of the present invention can be produced by reacting a hyperbranched polymer represented by the following formula (3) with an ethylene oxide represented by the following formula (4) in the presence of a base.

In the formula, R ¹ and A ¹ have the same meaning as above, l ′ has the same meaning as l, R ^{2 ″} has the same meaning as R ² and R ^{2 ′,} and X and X 'Represents a halogen atom, and k represents an integer of 1 to 40.

In the above reaction, the amount of the hyperbranched polymer represented by the formula (3) and the ethylene oxide represented by the formula (4) should be about 0.1 to 20 mol of ethylene oxide with respect to 1 mol of the hyperbranched polymer. However, about 1 to 5 mol is preferable.

The base used in the above reaction is not particularly limited as long as it is a base used in this kind of reaction. For example, hydrogenation such as sodium hydride, potassium hydride, rubium hydride, calcium hydride, etc. Use alkali metals and alkaline earth metal hydrides, inorganic bases such as potassium carbonate, calcium carbonate, sodium carbonate and cesium carbonate, and organic bases such as n-butyllithium, t-butyllithium, s-butyllithium and lithium diisopropylamide. In view of the balance between ease of handling and reactivity, alkali metal hydride is preferable, and sodium hydride is more preferable.
Although the usage-amount of a base can be about 0.1-20 mol% with respect to 1 mol of ethylene oxide, about 1-5 mol% is suitable.

In the above reaction, the terminal hydrogen atom of ethylene oxide represented by the formula (4) is extracted by the base, and the resulting anion compound is converted into halogen atoms (X and X in the hyperbranched polymer represented by the formula (3). The hyperbranched polymer of the present invention is produced by replacing ').
Examples of X and X ′ include a chlorine atom, a bromine atom, and an iodine atom. In consideration of the balance between the reactivity and stability of the hyperbranched polymer represented by the formula (3), X and X ′ are chlorine atoms. A hyperbranched polymer represented by the formula (3) is preferred.

The above reaction may be performed in a solvent. When using a solvent, various solvents can be used as long as they do not adversely affect the reaction.
Specific examples include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatic hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.), aromatic Group hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, etc.), ethers (diethyl ether, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), ketones (acetone, methyl ethyl ketone, Methyl isobutyl ketone, di- -Butyl ketone, cyclohexanone, etc.), amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), ureas (N, N-dimethyl) Imidazolidinone, tetramethyl urea, etc.), sulfoxides (dimethyl sulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.) and the like. These may be used alone or in combination of two or more. May be used.

The reaction temperature may be appropriately set within the range from the melting point to the boiling point of the solvent to be used. However, considering that the reaction is allowed to proceed efficiently, it is preferably about 0 to 200 ° C, more preferably 20 to 150 ° C.
After completion of the reaction, the target hyperbranched polymer can be obtained by post-treatment according to a conventional method.

The hyperbranched polymer represented by the above formula (3), which is a raw material compound, can be produced, for example, by halogenating the compound represented by the formula (5) with a halogenating agent such as sulfuryl chloride.

(Wherein R ¹ , X, X ′ and A ¹ have the same meaning as described above, and l ″ has the same meaning as the above l ′.)

As the hyperbranched polymer having a dithiocarbamate group represented by the formula (5) at the molecular end, a commercially available product can be used. As such a commercially available product, Hypertech (registered trademark) HPS-200 manufactured by Nissan Chemical Industries, Ltd. is suitable.

Living radical polymerization using a dithiocarbamate compound represented by formula (5) as a raw material to obtain a hyperbranched polymer represented by formula (3) is described in Macromolecules Vol. 35, no. 9, 3781-3784 (2002), Macromolecules Vol. 36, no. 10, 3505-3510 (2002), International Publication No. 2008/029688 pamphlet and the like.
In the above description, the method for synthesizing the hyperbranched polymer of the present invention using the hyperbranched polymer represented by the formula (3) as the synthesis raw material and the method for synthesizing the hyperbranched polymer as the raw material have been described in detail. This does not mean that the synthesis raw material of the hyperbranched polymer represented by the formula (1) of the present invention is limited to the hyperbranched polymer represented by the formula (3).

The hyperbranched polymer of the present invention described above exhibits high solubility in an organic solvent and high compatibility with a lithium salt, and the solid electrolyte obtained by removing the solvent from the solution containing the hyperbranched polymer and the lithium salt is: Since it has excellent ionic conductivity, it can be suitably used as a matrix polymer for a solid electrolyte of a secondary battery using a lithium salt as an electrolyte.
Next, the composition of the present invention which gives a solid electrolyte containing the hyperbranched polymer of the present invention as a matrix polymer will be described.

The composition of the present invention comprises the hyperbranched polymer of the present invention and a lithium salt.
Such a lithium salt is not particularly limited as long as it is a salt that is generally used for an electrolyte solution of a lithium battery or a lithium ion battery. For example, a lithium sulfonic acid imide salt, a lithium organic acid salt, a lithium inorganic acid salt, etc. Is mentioned. These may be used alone or in combination of two or more.

Specific examples of the lithium sulfonic acid imide salt include lithium bis (pentafluoroethanesulfonyl) imide (LiN (SO ₂ C ₂ F ₅ ) ₂ ), lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) And the like.

Specific examples of the lithium organic acid salt include lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium pentafluoroethanesulfonate (LiC ₂ F ₅ SO ₃ ), and the like.

Specific examples of the lithium inorganic salt, lithium lithium perchlorate (LiClO ₄₎ hexafluoroarsenate (LiAsF _6), lithium hexafluoro Henri Mont acid (LiSbF _6), lithium hexafluorophosphate (LiPF _6), tetra Examples thereof include lithium fluoroborate (LiBF ₄ ) and lithium bis (oxalato) borate (LiC ₄ BO ₈ ).
Among these, lithium sulfonic acid imide salt is preferable and LiN (SO ₂ CF ₃ ) ₂ is more preferable in consideration of the availability of lithium salt and the balance of physical strength and ion conductivity of the obtained solid electrolyte.

Although the mass ratio of the hyperbranched polymer and the lithium salt contained in the composition of the present invention is not particularly limited, the lithium salt can usually be about 0.01 to 1 with respect to the hyperbranched polymer 1. In consideration of improving the ionic conductivity of the obtained solid electrolyte, about 0.1 to 0.6 is preferable, and about 0.3 to 0.5 is more preferable.

The composition of the present invention can be obtained by mixing the hyperbranched polymer of the present invention and a lithium salt.
As a mixing method, for example, a method in which a hyperbranched polymer and a lithium salt are placed in a suitable container such as a mortar or beaker and sufficiently mixed using an instrument such as a pestle or a glass rod can be employed. At this time, for the purpose of further improving the uniformity of the mixture, the mixture may be heated at a temperature within a range where the compound does not decompose.
The composition obtained by mixing in this way can be used as a solid electrolyte as it is, or can be dissolved in an organic solvent and used for producing an electrolyte with improved ion conductivity according to the method described later. Good.

The composition of the present invention preferably contains an organic solvent in view of making the ionic conductivity uniform and improving the obtained solid electrolyte, improving the physical strength, and the like.
Such a composition can be obtained, for example, by dissolving the above composition, which is a mixture of a hyperbranched polymer and a lithium salt, in an organic solvent, or by separately dissolving the hyperbranched polymer and the lithium salt in an organic solvent. It can also be obtained by mixing a solution in which the hyperbranched polymer is dissolved with a solution in which the lithium salt is dissolved.

The organic solvent to be used is not particularly limited as long as it is a solvent that dissolves the hyperbranched polymer and the lithium salt satisfactorily and does not react with them. Specific examples include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatic hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.), aromatic hydrocarbons (benzene, nitrobenzene, toluene, o- Xylene, m-xylene, p-xylene, mesitylene, etc.), halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, etc.), alcohols (methanol, ethanol) , N-propanol, isopropanol, n-butanol, isobut Diol, tert-butanol, 2-ethylhexyl alcohol, benzyl alcohol), ethers (diethyl ether, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.) , Ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, cyclohexanone, etc.), esters (ethyl acetate, n-butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate) ), Amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone) γ-butyrolactone, etc.), ureas (N, N-dimethylimidazolidinone, tetramethylurea, etc.), sulfoxides (dimethyl sulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.) and the like. . These may be used alone or in combination of two or more.

Among these, aliphatic hydrocarbons, alcohols, and ketones are preferable, ketones are more preferable, and methyl isobutyl ketone is even more preferable.

  When a solvent is contained in the composition, the mass ratio of the solvent to the solid content (hyperbranched polymer and lithium salt) is not particularly limited, but is usually 0.01 to 1 solid content relative to the solvent 1. In view of ionic conductivity of the obtained solid electrolyte, 0.05 to 0.5 is preferable, and 0.07 to 0.2 is more preferable.

When producing a solid electrolyte using a composition containing an organic solvent, for example, a method of pouring the composition into an appropriate container or a method of applying the composition to a substrate to form a thin film is employed. can do.
As such a container, what gives a desired shape by taking out solid electrolyte after removing a solvent should just be used, and the material will not be specifically limited unless it reacts with a composition.
In addition, the application method of the composition to the base material takes into consideration the balance between the thickness of the electrolyte and the resistance value, drop casting method, spin coating method, blade coating method, dip coating method, roll coating method, bar coating method, die coating method Any one of various wet process methods such as a printing method, an ink jet method, a printing method (such as letterpress, intaglio, lithographic and screen printing) may be employed.

When removing a solvent from a composition containing an organic solvent to obtain a solid electrolyte, if necessary, use a heating device such as a hot plate or oven, in the atmosphere (normal pressure), in an inert gas such as nitrogen, or in vacuum Evaporate the solvent under a suitable atmosphere such as below.

When removing the solvent at the heating temperature, the heating temperature and the heating time are appropriately determined according to the boiling point of the solvent to be used, but prevent the hyperbranched polymer and lithium salt from being decomposed, sufficiently remove the solvent, etc. In view of the above, the heating temperature is preferably 80 ° C. to 150 ° C., more preferably 90 ° C. to 110 ° C. In consideration of the same, when the solvent is evaporated under normal pressure, the heating time is preferably within 6 hours, more preferably within 3 hours, and the solvent is evaporated under vacuum. In the case, it is preferably within 24 hours, more preferably within 15 hours.

In addition, the composition of the present invention is used for the purpose of improving the physical strength and ion conductivity of the solid electrolyte, improving the uniformity of the mixed state of solids, adjusting the viscosity of the composition, and the like. Including particles of inorganic solid electrolytes such as oxide-based solid electrolytes and sulfide-based solid electrolytes that can be used in lithium secondary batteries, as well as other linear polymers, within a range that does not significantly impair conductivity and self-supporting properties May be. These may be used alone or in combination of two or more.

As the inorganic solid electrolyte, Li _a X _b Y _c P _d O _e (X is at least one selected from the group consisting of B, Al, Ga, In, C, Si, Ge, Sn, Sb and Se). Y is at least one selected from the group consisting of Ti, Zr, Ge, In, Ga, Sn and Al, and a to e are 0.5 <a <5.0, 0 ≦ b <2. .98, 0.5 ≦ c <3.0, 0.02 <d ≦ 3.0, 2.0 <b + d <4.0, 3.0 <e ≦ 12.0. An oxide solid electrolyte having a perovskite structure represented by Li _3x La _{2 / 3-x} □ _{1 / 3-2x} TiO ₃ (□ represents a defect site); _{li 3 + x A y G z} M 2-v B v O 12 (A is selected Ca, Sr, Ba, Mg, from the group consisting of Zn G is at least one selected from the group consisting of La, Y, Pr, Nd, Sm, Lu, and Eu, and M is Zr, Nb, Ta, Bi, Te, and Sb. At least one selected from the group consisting of: B is In; and v to z have a relationship of 0 ≦ v ≦ 2, 0 ≦ x ≦ 5, 0 ≦ y ≦ 3, and 0 ≦ z ≦ 3. Li ₂ , an oxide-based solid electrolyte having a garnet-type structure, in which O is partially or completely replaced with a divalent anion and / or a trivalent anion (eg, N ³⁻ ). _{S-P 2 S 5, Li} 2 S-SiS 2, Li 3.25 P 0.25 Ge 0.76 S 4, Li 4-x Ge 1-x P x S 4, Li 7 P 3 S 11, Li 2 S-SiS 2 - Examples thereof include sulfide-based solid electrolyte particles such as Li ₃ PO ₄ glass.

Other linear polymers include starch, polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, regenerated cellulose, diacetylcellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer ( EPDM), sulfonated EPDM, styrene butadiene rubber, fluoro rubber, tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, fluorinated Vinylidene-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetra Fluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetra Fluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic Examples thereof include acid methyl copolymers, polysaccharides such as polyethylene oxide, thermoplastic resins, and polymers having rubber elasticity.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example.

The abbreviations of the reagents used are as follows.
[solvent]
IPA: isopropyl alcohol (manufactured by Kanto Chemical Co., Inc.)
Cyclohexene (manufactured by Tokyo Chemical Industry Co., Ltd.)
THF: tetrahydrofuran (manufactured by Kanto Chemical Co., Inc.)
MIBK: Methyl isobutyl ketone (manufactured by Junsei Chemical Co., Ltd.)
[reagent]
HPS: Hyperbranched polystyrene [Hypertech (registered trademark) HPS-200 manufactured by Nissan Chemical Industries, Ltd.]
NaH: Sodium hydride (Wako Pure Chemical Industries, Ltd.)
LiTFSI: Lithium bis (trifluoromethanesulfonyl) imide (manufactured by Kanto Chemical Co., Inc.)
TEGMME: Tetraethylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
Me (PEG) OH350: Polyethylene glycol monomethyl ether (Mn: 350) (Alfa Aesar)
Me (PEG) OH1900: Polyethylene glycol monomethyl ether (Mn: 1900) (Alfa Aesar)
PEG200: Polyethylene glycol 200 (average molecular weight: 200) (manufactured by Junsei Chemical Co., Ltd.)
PEG600: Polyethylene glycol 600 (average molecular weight: 600) (manufactured by Pure Chemical Co., Ltd.)
PEG 1500: Polyethylene glycol 1500 (average molecular weight: 1500) (manufactured by Junsei Chemical Co., Ltd.)
PEG35000: Poly (ethylene glycol) (average Mn 35,000) (manufactured by ALDRICH)
PEO100000: poly (ethylene oxide) (average Mn 100,000) (manufactured by ALDRICH)

[Synthesis Example 1] Synthesis of HPS-Cl (Compound 1)

In a 20 L reaction vessel, sulfuryl chloride (manufactured by Kishida Chemical Co., Ltd.) 1.28 kg (9.50 mol, 3.6 equivalents relative to a dithiocarbamate group (hereinafter referred to as DC group) of HPS described later) and chloroform ( Kanto Chemical Co., Ltd.) 2.35 kg was charged and stirred to dissolve uniformly. The solution was cooled to 0 ° C. under a nitrogen stream. In another 10 L reaction vessel, 700 g of HPS (2.64 mol as a DC group) and 7.00 kg of chloroform, which are hyperbranched polymers having a DC group at the molecular end, and 7.00 kg of chloroform were charged and stirred under a nitrogen stream until uniform. This solution was transferred to a 3 L separatory funnel equipped in the 20 L reaction vessel with a pump under a nitrogen stream. In the sulfuryl chloride / chloroform solution cooled to 0 ° C., the HPS / chloroform solution transferred to the 3 L separatory funnel under a nitrogen stream is adjusted so that the temperature of the reaction solution becomes −5 ± 5 ° C. Added over 60 minutes. After completion of the addition, the mixture was stirred for 6 hours while maintaining the temperature of the reaction solution at −5 ± 5 ° C. Further, a solution obtained by dissolving 0.78 kg (9.50 mol, 1.0 equivalent to sulfuryl chloride) of cyclohexene (manufactured by Tokyo Chemical Industry Co., Ltd.) in 2.35 kg of chloroform was added to this reaction solution, and the temperature of the reaction solution was − It added so that it might become 5 +/- 5 degreeC. After the addition, the reaction solution was added to 46.7 kg of IPA to precipitate the polymer. The white powder obtained by filtering this precipitate was washed with 5.25 kg of IPA and vacuum dried at 40 ° C. to obtain 399 g of a hyperbranched polymer (compound 1) having a chlorine atom at the molecular end as a white powder. .
The weight average molecular weight Mw measured by polystyrene conversion by GPC of the obtained HPS-Cl was 14,000 (dispersion degree Mw / Mn 2.9). The number 1 of weight average repeating structural units of HPS-Cl can be calculated as 92. The measurement result of ¹ H-NMR is shown in FIG.

[Synthesis Example 2] Synthesis of Compound 2 A three-necked flask (1 L) was equipped with a dropping funnel and a water-cooled tube, and a stirrer was placed therein. NaH (9.6 g, 240 mmol) and THF (50 g) were sequentially added to the flask, and the atmosphere in the system was replaced with nitrogen. A solution of TEGMME (49.3 g, 300 mmol) dissolved in THF (80 g) was added over 10 minutes from the dropping funnel, and the wall of the dropping funnel was washed with THF (20 g). After stirring for 30 minutes, a solution of compound 1 (30.4 g, 200 mmol) dissolved in THF (40 g) was added over 5 minutes from the dropping funnel, and the wall of the dropping funnel was washed with THF (10 g). The temperature of the reaction solution was heated to 50 ° C. and stirred for 16 hours.
After the reaction, the reaction mixture was cooled to room temperature and purified by column chromatography (Wakogel C60, developing solvent THF). The solvent of the solution obtained after the purification was distilled off with a rotary evaporator. Compound 2 was obtained as a colorless and transparent liquid (amount obtained: 38.2 g, yield: 69%). The measurement result of ¹ H-NMR is shown in FIG.
As shown in FIGS. 1, 2 and 5, the peak attributed to hydrogen of the methylene group present in the hyperbranched polymer is shifted from 4.52 ppm to 4.42 ppm. From this result, it is understood that the chlorine atom bonded to the methylene group is replaced with an oxygen atom from ethylene oxide.

[Synthesis Example 3] Synthesis of Compound 3 A three-necked flask (1 L) was equipped with a dropping funnel and a water-cooled tube, and a stirrer was placed therein. NaH (0.96 g, 24 mmol) and THF (50 g) were sequentially added to the flask, and the system was purged with nitrogen. A solution of Me (PEG) OH350 (52.5 g, 30 mmol) dissolved in THF (80 g) was added from the dropping funnel over 10 minutes, and the wall of the dropping funnel was washed with THF (20 g). After stirring for 30 minutes, a solution prepared by dissolving Compound 1 (3.04 g, 20 mmol) synthesized by the method of Preparation Example 1 in THF (40 g) was added over 5 minutes from the dropping funnel, and the dropping funnel was added with THF (10 g). I washed the wall. The temperature of the reaction solution was heated to 50 ° C. and stirred for 16 hours.
After the reaction, the reaction mixture was cooled to room temperature and purified by column chromatography (Wakogel C60, developing solvent THF. The solvent of the solution obtained after purification was distilled off with a rotary evaporator. Compound 3 was obtained as a colorless transparent jelly ( (Yield: 6.7 g, yield: 72%) ¹ H-NMR measurement results are shown in FIG.
As shown in FIGS. 1, 3 and 5, the peak attributed to the proton of the methylene group present in the hyperbranched polymer is shifted from 4.52 ppm to 4.40 ppm. From this result, it is understood that the chlorine atom bonded to the methylene group is replaced with an oxygen atom from ethylene oxide.

[Comparative Synthesis Example 1] Synthesis of Compound 4 A three-necked flask (1 L) was equipped with a dropping funnel and a water-cooled tube, and a stir bar was added. NaH (0.48 g, 12 mmol) and THF (25 g) were sequentially added to the flask, and the system was purged with nitrogen. A solution of Me (PEG) OH1900 (28.5 g, 15 mmol) dissolved in THF (40 g) was added over 10 minutes from the dropping funnel, and the wall of the dropping funnel was washed with THF (10 g). After stirring for 30 minutes, a solution of compound 1 (1.52 g, 10 mmol) dissolved in THF (20 g) was added over 5 minutes from the dropping funnel, and the wall of the dropping funnel was washed with THF (5 g). The temperature of the reaction solution was heated to 50 ° C. and stirred for 16 hours.
After the reaction, the reaction mixture was cooled to room temperature and purified by column chromatography (Wakogel C60, developing solvent THF). The solvent of the solution obtained after the purification was distilled off with a rotary evaporator. Compound 4 was obtained as a yellow solid (11.5 g yield, 57% yield). The measurement result of ¹ H-NMR is shown in FIG.
As shown in FIGS. 1, 4 and 5, the peak attributed to the proton of the methylene group present in the hyperbranched polymer is shifted from 4.52 ppm to around 4.40 ppm, and FIGS. As shown in FIG. ¹ , in the ¹ H-NMR measurement of Compound 4, a peak (2.17 ppm) attributed to the proton of the hydroxyl group of Me (PEG) OH1900, which is the reactant, was not observed. From these results, it is understood that the chlorine atom bonded to the methylene group is replaced with an oxygen atom from ethylene oxide.

[Example 1]
(Production of solid electrolyte)
10.05 g of MIBK and 1.75 g of compound 2 were put into an eggplant type flask, and stirred and dissolved at 80 ° C. for 30 minutes.
To this solution was added 0.75 g of LiTFSI, and the mixture was further stirred and dissolved at 80 ° C. for 30 minutes.
The obtained solution was poured into a PFA petri dish (φ50 × φ55 × 10 × 13) under normal pressure, heated on a hot plate at 100 ° C. for 3 hours, and then the sample was transferred to a dryer. C. for 15 hours under vacuum. After drying, the sample was transferred into a glove box under an argon atmosphere.
The film on the PFA petri dish could be peeled off as a free-standing film.
[Ion conductivity evaluation]
A small piece of 1 cm × 1 cm was cut out from the peeled film, and this small piece was sandwiched between two aluminum electrodes. This was taken out from the glove box, and the AC impedance method was used at room temperature (25 ° C.) under an argon atmosphere. In addition, ion conductivity is defined as the following formula.
[Ionic conductivity (S / cm)] = 1 / (R × s) × l
In the formula (1), R represents the resistance value of the solid polymer electrolyte, s represents the cross-sectional area (cm ² ) of the solid polymer electrolyte, and l represents the film thickness (cm) of the solid polymer electrolyte membrane. The resistance value is measured by an AC impedance method (measuring device: PARSTAT [registered trademark] 2273 Advanced Electrochemical System, Princeton Applied Research), and the film thickness is measured by a micrometer (Quick Micro MDQ-30, manufactured by Mitutoyo Corporation). Was used. The resistance value was 4100Ω and the film thickness was 0.074 cm.

[Example 2]
A solid electrolyte was prepared and ion conductivity was measured in the same manner as in Example 1 except that Compound 3 was used instead of Compound 2.
In addition, the film | membrane on the obtained PFA petri dish was able to peel off as a self-supporting film | membrane like the case of Example 1. FIG. The ionic conductivity was measured using the same method as in Example 1, the resistance value was 2400Ω, and the film thickness was 0.056 cm.

[Comparative Example 1]
Preparation of a solid electrolyte was attempted in the same manner as in Example 1 except that Compound 4 was used instead of Compound 2. However, even after the vacuum drying was completed, the mixture remained in a liquid state, and a solid electrolyte could not be produced.

[Comparative Example 2]
Production of a solid electrolyte was attempted in the same manner as in Example 1 except that Compound 1 was used instead of Compound 2. However, the obtained solid was not flexible at all, and a solid electrolyte membrane could not be produced.

[Comparative Examples 3 to 6]
In the same manner as in Example 1 except that 1.14 g of each molecular weight polyether compound (PEG200, PEG1500, PEG35000, PEO100000) was used instead of compound 2, and the amount of LiTFSI used was 0.50 g. An attempt was made to produce a solid electrolyte. However, even after the vacuum drying was completed, the mixture remained in a liquid state, and a solid electrolyte membrane could not be produced.

[Comparative Examples 7 and 8]
A solid electrolyte was prepared in the same manner as in Example 1 except that 1.58 g of Compound 1 and 0.20 g of PEG200, 0.88 g of Compound 1 and 0.88 g of PEG200 were used instead of Compound 2, respectively. It was. However, after the vacuum drying was completed, the membrane was separated into a liquid phase and a solid phase, and a solid electrolyte membrane could not be produced.

[Comparative Examples 9 and 10]
A solid electrolyte was prepared in the same manner as in Example 1 except that 1.58 g of compound 1 and 0.18 g of PEG 600 and 0.88 g of compound 1 and 0.88 g of PEG 600 were used instead of compound 2, respectively. It was. However, after the vacuum drying was completed, the membrane was separated into a liquid phase and a solid phase, and a solid electrolyte membrane could not be produced.

[Comparative Examples 11 and 12]
A solid electrolyte was prepared in the same manner as in Example 1 except that 1.58 g of compound 1 and 0.19 g of PEG 1500 and 0.89 g of compound 1 and 0.88 g of PEG 1500 were used instead of compound 2, respectively. It was. However, after the vacuum drying was completed, the membrane was separated into a liquid phase and a solid phase, and a solid electrolyte membrane could not be produced.
Table 1 shows the results of measurement of the solid electrolyte and the measurement results of ionic conductivity. In Table 1, the solid content ratio means the mass ratio (%) of each additive to the total amount of solid content (total amount of polymer and LiTFSI).

The hyperbranched polymer (compound 2 or 3) having an ethylene oxide chain having 4 or 7 to 8 units at the end and a solid electrolyte containing LiTFSI have physical strength that can be collected as a free-standing film. It was suggested that the solid electrolyte used as a polymer could be produced (Examples 1 and 2).
On the other hand, when compound 1 (raw material of compounds 2 to 4) was used as a matrix polymer, the mixture obtained by removing the solvent was brittle and did not have enough physical strength to be collected as a free-standing film (comparison) Example 2). Moreover, the compound 4 which is a hyperbranched polymer having a longer ethylene oxide chain (unit number 42 to 43) at the terminal is liquefied by mixing with LiTFSI, and a solid electrolyte containing the compound 4 cannot be produced (Comparative Example). 1) Similarly, even when linear PEG was used, the mixture of PEG and salt was liquefied, and solid electrolytes containing these polymers could not be produced (Comparative Examples 3 to 6).
When compound 1 and linear PEG were mixed and used as a matrix polymer, the mixture separated into a liquid and a solid after completion of vacuum drying, and solid electrolytes could not be obtained (Comparative Examples 7 to 12). ).
From these results, it can be seen that compounds 2 and 3 are suitable as a matrix polymer.

[Example 3]
[Production of thin-film solid electrolyte and resistance measurement]
17.47 g of MIBK and 0.38 g of Compound 2 were put into a screw tube, and stirred and dissolved at room temperature for 30 minutes.
To this solution, 0.16 g of LiTFSI was added and further stirred and dissolved at room temperature for 30 minutes.
The obtained solution was applied by spin coating to a glass substrate on which ITO was deposited with a width of 2 mm (area 0.04 cm ² ) under normal pressure (spin coating condition 500 rpm 5 seconds + 2000 rpm 20 seconds). After heating at 10 ° C. for 10 minutes, the sample was transferred to a dryer and dried at 100 ° C. under vacuum for 1 hour. The obtained thin film was made into the resistance measurement cell (cell 1) of the polymer solid electrolyte thin film by vapor-depositing aluminum by 2b * 10 <^-4> Pa with width 2mm.
A cell was prepared by the same method as described above except that a thin film was not formed by spin coating, and this was used as a single cell for resistance measurement (cell 2).
The resistances of the cell 1 and the cell 2 were performed in the same manner as in Example 1. The difference between the resistance value of the cell 1 and the resistance value of the cell 2 thus obtained was defined as the resistance value of the polymer solid electrolyte. The resistance value of the polymer solid electrolyte thus obtained was 50.6Ω (assumed film thickness of 300 nm).
The resistance value of the thin film solid electrolyte of Non-Patent Document 2 using a compound having good lithium ion conductivity among polymer solid electrolytes is 2 × at 30 ° C. from the conductivity and film thickness described in Non-Patent Document 2. 10 ³ Ω (when the cross-sectional area is 0.04 cm ^{2 as in} the case of the cell 1) is calculated. It can be seen that the resistance value of the thin film obtained from the composition of the present invention is 1/30 or less, which is extremely low.
From these results, by using the composition of the present invention, it is possible to produce a thin film having higher ion conductivity than when using a known polymer compound having good lithium ion conductivity. You can see that
By using the thin-film solid electrolyte obtained from the composition of the present invention, it is expected that the secondary battery using the lithium salt as an electrolyte can be reduced in size and weight and improved in cycle characteristics and rate characteristics due to reduction in internal resistance.

Claims (16)

Formula (1)

{Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² and R ^{2 ′} each independently represent an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, or 3 carbon atoms. A cycloalkyl group having 20 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. A heteroaromatic group of (these alkyl group, haloalkyl group, cycloalkyl group, bicycloalkyl group, alkenyl group, alkynyl group, aromatic group and heteroaromatic group may be substituted with Z), A ¹ is the formula (2)

[Wherein, A ² represents an alkylene group having 1 to 20 carbon atoms (which may be substituted with Z and may include an ether group or an ester group), and Y ^{1 to} Y ⁴ each independently represent , Hydrogen atom, halogen atom, nitro group, cyano group, amino group, hydroxyl group, thiol group, phosphoric acid group, sulfonic acid group, carboxyl group, alkyl group having 1 to 20 carbon atoms, haloalkyl group having 1 to 20 carbon atoms , A cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms, or carbon The heteroaromatic group of number 2-20 is shown. Z represents a halogen atom, a nitro group, a cyano group, an amino group, a hydroxyl group, a thiol group, a phosphoric acid group, a sulfonic acid group, a carboxyl group, or an alkoxy having 1 to 20 carbon atoms. Group, a thioalkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, An alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 1 to 20 carbon atoms, an aromatic group having 6 to 20 carbon atoms or a heteroaromatic group having 2 to 20 carbon atoms; l shows the integer of 2-100,000, n and m show the integer of 1-40 each independently. } The hyperbranched polymer shown. The hyperbranched polymer according to claim 1, wherein n and m are each independently 2 to 7. The hyperbranched polymer according to claim 1, wherein Y ^{1 to} Y ⁴ are each independently a hydrogen atom or a methyl group, and the A ² is a methylene group, an ethylene group, or an n-propylene group. Wherein R ² and R ^{2 'are} each independently, hyperbranched polymer according to claim 1 is a methyltransferase or phenyl. The matrix polymer which consists of a hyperbranched polymer of any one of Claims 1-4. A solid electrolyte comprising the matrix polymer according to claim 5. The solid electrolyte according to claim 6, further comprising a lithium salt. The solid electrolyte according to claim 7, wherein the lithium salt is at least one selected from a lithium sulfonic acid imide salt, a lithium organic acid salt, and a lithium inorganic acid salt. It is a thin film form, The solid electrolyte of any one of Claims 5-8. The secondary battery which has a solid electrolyte of any one of Claims 5-9. The composition containing the hyperbranched polymer of any one of Claims 1-4, and lithium salt. The composition according to claim 11, wherein the lithium salt is at least one selected from a lithium sulfonic acid imide salt, a lithium organic acid salt, and a lithium inorganic acid salt. The composition according to claim 11 or 12, further comprising an organic solvent. It is an object for solid electrolytes, The composition of any one of Claims 11-13. The manufacturing method of the solid electrolyte which has the process of removing a solvent from the composition of Claim 13 or 14. And Ruha Lee par-branched polymer represented by the formula (3), the method of producing the hyperbranched polymer according to claim 1, characterized in that the reaction of ethylene oxide of the formula (4) in the presence of a base catalyst .

(Wherein R ¹ and A ¹ have the same meaning as above, l ′ has the same meaning as l, R ^{2 ″} has the same meaning as R ² and R ^{2 ′,} and X and X ′ represents a halogen atom, and k represents an integer of 1 to 40.)