JP2015173017A - polymer electrolyte composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer electrolyte composition which enables formation of a protective film capable of making high ion conductivity at ordinary temperature compatible with cycle life characteristics of a battery on the surface of lithium metal.SOLUTION: A polymer electrolyte composition comprises (A) a cross-linked body of a polymer having a polyether chain (a1), (B) a linear polymer having a polyether chain (b1) and (C) a lithium salt. The number average molecular weight of (a1) is 100-5,000; the number average molecular weight of (b1) is 500-5,000; and the total content of the polyether chains in (A) and (B) is 40-99 wt.% with respect to the total weight of (A) and (B).

Description

  The present invention relates to a polymer electrolyte composition.

  In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries as power sources has increased. A battery used for the above applications is required to be used at room temperature, and at the same time, a high energy density and excellent cycle characteristics are required.

In response to the above demand, the lithium metal battery has a low density of 0.54 g / cm ³ and a standard reduction potential of −3.045 V, which is very low, so that the capacity can be increased. Research for practical application as a generation secondary battery is underway.

  However, since lithium metal with very high reactivity is used as the negative electrode active material, if an appropriate electrolyte that does not react with lithium metal cannot be selected, lithium metal dendrites (dendrites) are generated during charging and discharging. There is a problem of deteriorating the life characteristics.

Conventionally, a technique for forming a pretreatment layer and a protective layer (hereinafter referred to as a protective film) using a polymer electrolyte on the surface of lithium metal has been disclosed as a method for suppressing the deterioration of the cycle life characteristics as described above ( For example, Patent Documents 1 to 3).
However, as in Patent Documents 1 and 2, when a polymer skeleton-containing low molecule is contained as a plasticizer in the crosslinked polymer, there is a problem that the low molecular plasticizer is eluted into the electrolytic solution and the cycle life characteristics are deteriorated. Moreover, when the linear polymer of polyether is included in the polymer cross-linked body as in Patent Document 3, there is a problem that ion conductivity at room temperature decreases due to crystallization of the polyether chain.
Therefore, a protective film formed on the surface of the lithium negative electrode is desired that can achieve both high ion conductivity at room temperature and cycle life characteristics of the battery.

US Patent Application Publication No. 2002/0012846 Japanese Patent Laying-Open No. 2005-071998 JP 2005-142156 A

  The present invention provides a polymer electrolyte composition and a method for producing the polymer electrolyte composition capable of forming a protective film capable of achieving both high ion conductivity at room temperature and cycle life characteristics of a battery on the surface of lithium metal. With the goal.

The present invention provides a polymer electrolyte composition comprising a crosslinked polymer (A) having a polyether chain (a1), a linear polymer (B) having a polyether chain (b1), and a lithium salt (C). The number average molecular weight of (a1) is 100 to 5,000, the number average molecular weight of (b1) is 500 to 5,000, and the total content of the polyether chains in (A) and (B) A polymer electrolyte composition whose amount is 40 to 99% by weight based on the total weight of (A) and (B); a method for producing a polymer electrolyte composition, wherein the linear polymer (B) and the following polyether It is a method for producing a polymer electrolyte composition comprising a step of polymerizing (d) in a monomer solution (X) containing a compound (d) having a chain (a1) to produce a crosslinked polymer (A).
Compound (d) having (a1): (meth) acrylate compound (d1) having two or more (meth) acrylate groups and / or epoxy compound (d2) having two or more epoxy groups.

The polymer electrolyte composition of the present invention can form a protective layer excellent in high ion conductivity and recycle life characteristics at room temperature on the surface of lithium metal.
Moreover, the manufacturing method of the polymer electrolyte composition of this invention can obtain the polymer electrolyte composition which can form the protective layer which is excellent in the high ion conductivity in normal temperature, and a recycle life characteristic.

2 illustrates a cross-sectional structure of an example of a lithium metal secondary battery.

  The polymer electrolyte composition of the present invention contains a crosslinked polymer (A) having a polyether chain (a1), a linear polymer (B) having a polyether chain (b1), and a lithium salt (C). A polymer electrolyte composition, wherein the polyether chain (a1) has a number average molecular weight (hereinafter sometimes abbreviated as Mn) of 100 to 5,000, and the polyether chain (b1) has an Mn of 500 to 5 And the total content of polyether chains in (A) and (B) is 40 to 99% by weight based on the total weight of (A) and (B).

In the crosslinked polymer (A), the polyether chain (a1) is represented by polymerized alkylene oxide having 2 to 4 carbon atoms [{-(O—R) _n —}, where R is 2 carbon atoms. -4 alkyl groups, n is a number from 3 to 120, and represents the average number of moles added of the oxyalkylene group, and is not necessarily an integer].
Examples of the alkylene oxide include ethylene oxide (hereinafter sometimes abbreviated as EO), propylene oxide, butylene oxide, and the like.
(A1) may be one using an alkylene oxide or a combination of two or more.
When two or more types are used in combination, the coupling type may be either block coupling or random coupling.
Examples of (a1) include a polyoxyethylene chain, a polyoxypropylene chain and a polyoxyethylene polyoxypropylene chain.
The polyether chain (a1) is preferably a polyoxyethylene chain from the viewpoint of ion conductivity and battery cycle life.

The polymer crosslinked body (A) has a polyether chain (a1) and includes a compound (d) having (a1) as an essential constituent monomer.
The compound (d) includes a (meth) acrylate compound (d1) having two or more (meth) acrylate groups and / or an epoxy compound (d2) having two or more epoxy groups.

  (D1) includes a (meth) acrylate compound having a polyether chain (a1), 2 to 6 (meth) acrylate groups, and 2 (meth) acrylate groups. Acrylate compound (d12), (meth) acrylate compound (d13) having 3 (meth) acrylate groups, (meth) acrylate compound (d14) having 4 (meth) acrylate groups, 5 (meth) A (meth) acrylate compound (d15) having an acrylate group and a (meth) acrylate compound (d16) having six (meth) acrylate groups are included.

As the (meth) acrylate compound (d12) having two (meth) acrylate groups, polyalkylene glycol (meth) acrylic acid diester {polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate and polytetra Methylene glycol di (meth) acrylate etc.}, aromatic diol alkylene oxide adduct (meth) acrylic acid diester {ethoxylated bisphenol A di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, etc.], (meth) acrylic acid diester of an alkylene diol alkylene oxide adduct having 5 to 22 carbon atoms of alkyl {ethoxylation-1, 10-decandio Rudi (meth) acrylate, propoxylated-1,10-decandiol di (meth) acrylate, ethoxylated-1,6-hexanediol di (meth) acrylate, propoxylated-1,6-hexanediol di (meth) acrylate , Ethoxylated-1,9-nonanediol di (meth) acrylate, propoxylated-1,9-nonanediol di (meth) acrylate, etc.}.
Among (d12), from the viewpoint of making the film strength and ionic conductivity of the protective film compatible, (meth) acrylic acid diester of polyalkylene glycol and (meth) acrylic acid diester of aromatic diol alkylene oxide adduct are preferable. Polyethylene glycol di (meth) acrylate and ethoxylated bisphenol A di (meth) acrylate are preferred.

  The (meth) acrylate compound (d13) having three (meth) acrylate groups is a (meth) acrylic acid triester of an alkylene oxide adduct of a trivalent or higher aliphatic alcohol {ethoxylated glycerin tri (meth) acrylate. , Propoxylated glycerin tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) Acrylate, ethoxylated-1,2,4-butanetriol tri (meth) acrylate and propoxylated-1,2,4-butanetriol tri (meth) acrylate, etc.} of trivalent or higher aromatic alcohol (Meth) acrylic acid triester of xylene oxide adduct {ethoxylated hydroxyquinol tri (meth) acrylate, propoxylated hydroxyquinol tri (meth) acrylate, ethoxylated phloroglucinol tri (meth) acrylate, propoxylated phloroglucinol tri (Meth) acrylate, ethoxylated pyrogallol tri (meth) acrylate, propoxylated pyrogallol tri (meth) acrylate, etc.} and ethoxylated isocyanuric acid tri (meth) acrylate.

  As the (meth) acrylate compound (d14) having four (meth) acrylate groups, a (meth) acrylic acid tetraester of an alkylene oxide adduct of a tetravalent or higher valent alcohol {ethoxylated pentaerythritol tetra (meth) acrylate and Ethoxylated ditrimethylolpropane tetra (meth) acrylate and the like} and the like.

  As the (meth) acrylate compound (d15) having 5 (meth) acrylate groups, (meth) acrylic acid pentaester of ethoxylated dipentaerythritol penta (meth) acrylate of an alkylene oxide adduct of pentavalent or higher valent alcohol Etc.

  As the (meth) acrylate compound (d16) having 6 (meth) acrylate groups, (meth) acrylic acid hexaester of an alkylene oxide adduct of 6 or more valent alcohol {ethoxylated dipentaerythritol hexa (meth) acrylate Etc.

  (D2) includes an epoxy compound having a polyether chain (a1) and having 2 to 6 epoxy groups, including an epoxy compound (d22) having 2 epoxy groups and 3 epoxy groups. The epoxy compound (d23), the epoxy compound (d24) which has 4 epoxy groups, the epoxy compound (d25) which has 5 epoxy groups, and the epoxy compound (d26) which has 6 epoxy groups are included.

  Examples of the epoxy compound having two epoxy groups (d22) include polyalkylene glycol diglycidyl ether {polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, etc.}, aromatic diol alkylene oxide Addition diglycidyl ether {ethoxylated bisphenol A diglycidyl ether, propoxylated ethoxylated bisphenol A diglycidyl ether, propoxylated bisphenol A diglycidyl ether, etc.}, alkylene oxide addition of alkylene diol having 5 to 22 carbon atoms in alkyl Diglycidyl ether adduct {ethoxylated-1, 10-decandiol diglycidyl ether, propoxylated-1,10- Candiol diglycidyl ether, ethoxylated-1,6-hexanediol diglycidyl ether, propoxylated-1,6-hexanediol diglycidyl ether, ethoxylated-1,9-nonanediol diglycidyl ether and propoxylated-1, 9-nonanediol diglycidyl ether, etc.}.

  As the epoxy compound (d23) having three epoxy groups, triglycidyl ether of an alkylene oxide adduct of a trihydric or higher aliphatic alcohol {ethoxylated glycerin triglycidyl ether, propoxylated glycerin triglycidyl ether, ethoxylated pentaerythritol Triglycidyl ether, propoxylated pentaerythritol triglycidyl ether, ethoxylated trimethylolpropane triglycidyl ether, propoxylated trimethylolpropane triglycidyl ether, ethoxylated-1,2,4-butanetriol triglycidyl ether and propoxylated-1, 2,4-butanetriol triglycidyl ether, etc.} triglycidyl ether of alkylene oxide adduct of trivalent or higher aromatic alcohol Ethoxylated hydroxyquinol triglycidyl ether, propoxylated hydroxyquinol triglycidyl ether, ethoxylated phloroglucinol triglycidyl ether, propoxylated phloroglucinol triglycidyl ether, ethoxylated pyrogallol triglycidyl ether, propoxylated pyrogallol triglycidyl ether and the like} and And ethoxylated isocyanuric acid triglycidyl ether.

  Examples of the epoxy compound (d24) having four epoxy groups include tetraglycidyl ethers of alkylene oxide adducts of tetravalent or higher valent alcohols such as ethoxylated pentaerythritol tetraglycidyl ether and ethoxylated ditrimethylolpropane tetraglycidyl ether. Can be mentioned.

  Examples of the epoxy compound (d25) having five epoxy groups include pentaglycidyl ethers {e.g., ethoxylated dipentaerythritol pentaglycidyl ethers) of alkylene oxide adducts of five or more valent alcohols.

  Examples of the epoxy compound (d26) having 6 epoxy groups include hexaglycidyl ether {eg, ethoxylated dipentaerythritol hexaglycidyl ether) of an alkylene oxide adduct of hexavalent or higher alcohol.

The crosslinked polymer (A) is a (meth) acrylate compound (d1) having two or more (meth) acrylate groups as essential constituent monomers from the viewpoint of achieving both the strength of the protective film and the ion conductivity. And / or an epoxy compound (d2) having two or more epoxy groups is preferably an essential constituent monomer, more preferably a (meth) acrylate compound (d12) having two (meth) acrylate groups, Selected from the group consisting of a (meth) acrylate compound having three (meth) acrylate groups (d13), an epoxy compound having two epoxy groups (d22), and an epoxy compound having three epoxy groups (d23) At least one kind is an essential constituent monomer.
It is.
(A) may be a compound using one type of compound (d) or a combination of two or more types.

In addition to the compound (d), the polymer crosslinked body (A) may contain another monomer (e) as a constituent monomer.
(E) includes monofunctional (meth) acrylate (e1), (meth) acrylate (e2) having two or more (meth) acrylate groups not having polyether chain (a1), monofunctional epoxy compound (e3) ) And an epoxy compound (e4) having two or more epoxy groups not having a polyether chain (a1).

  (E1) is an alicyclic group such as isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, etc. (Meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone modified tetrahydrofurfuryl (meth) acrylate, ethoxy modified cresol (meth) acrylate, propoxy modified cresol (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, carbazole ( Poly) ethoxy (meth) acrylate, carbazole (poly) propoxy (meth) acrylate, (poly) caprolactone modified carbazole (meth) acrylate, binaphth (Meth) acrylate, binaphthol (poly) ethoxy (meth) acrylate, binaphthol (poly) propoxy (meth) acrylate, (poly) caprolactone modified binaphthol (meth) acrylate and other (meth) acrylates and imide rings Imide (meth) acrylate having a structure, butanediol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) ) Acrylate, dipropylene glycol (meth) acrylate and other hydroxyl group-containing (meth) acrylates, dimethylaminoethyl (meth) acrylate, butoxyethyl (meth) acrylate, caprolactone (meth) Acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, octafluoropentyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, 2- (Meth) acrylates having an alkyl group such as ethylhexyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isomyristyl (meth) acrylate, lauryl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, 2 -Multivalent alcohols such as ethylhexyl carbitol (meth) acrylate, polyethylene glycol (meth) acrylate and polypropylene glycol (meth) acrylate Examples include (meth) acrylates of coal.

  (E2) includes hydropivalaldehyde-modified trimethylolpropane di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polypropoxydi (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, hexahydrophthalic acid Acrylic isocyanates such as di (meth) acrylate, binaphthol polyethoxydi (meth) acrylate, bisphenoxy (poly) polyethoxyfluorene and other aromatic rings (meth) acrylate, binaphthol di (meth) acrylate, diacrylated isocyanurate 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, etc. It is below.

  Examples of (e3) include phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, and 3-vinylcyclohexene oxide .

  Examples of (e4) include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, epoxy novolac resin, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2 -(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, methyle Bis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylene bis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, Epoxy hexahydrophthalic acid di-2-ethylhexyl, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene Glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8-diepoxyoctane and 1,2,5,6-diepoxy cyclooctane, and the like.

Among the monomers constituting the crosslinked polymer (A), the content of the compound (d) is preferably 50 to 100% by weight, more preferably 80 to 100% by weight, from the viewpoint of the film strength of the protective film. It is.
Among the monomers constituting (A), the content of (e) is preferably 0 to 50% by weight, more preferably 0 to 20% by weight, from the viewpoint of the film strength of the protective film.

In the crosslinked polymer (A), the Mn of the polyether chain (a1) is 100 to 5,000, but from the viewpoint of balancing the film strength and ion conductivity of the protective film and from the viewpoint of the cycle life of the battery. 500 to 4,000, more preferably 500 to 3,000.
When the Mn of the polyether chain (a1) is 100 or more, the cycle life characteristics of the battery are improved, and when it is 5,000 or less, the ion conductivity of the protective film at room temperature can be increased.

The content of the polyether chain (a1) in the polymer crosslinked body (A) is preferably 20 to 80, more preferably 40 to 80% by weight from the viewpoint of achieving both the film strength and the ionic conductivity of the protective film. is there.
The content of (a1) in (A) can be determined by solid state NMR. Moreover, it is computable from content of the polyether chain | strand (a1) in (d) used for manufacture of (A), and the ratio of (d) used. Moreover, content of the polyether chain | strand (a1) in (d) can be calculated | required by < ¹ > H-NMR.

The molecular weight between crosslinks of the crosslinked polymer (A) is preferably from 300 to 6,000 g / mol, more preferably from 1,500 to 4,000 g / mol, from the viewpoint of achieving both ionic conductivity and film strength of the protective film. mol.
The molecular weight between crosslinks represents a value obtained by dividing the number average molecular weight of the monomer constituting (A) by the average number of functional groups, and the number of moles of monomer in producing (A), the number average. It calculates | requires by following numerical formula (1) from molecular weight and average functional group number.
Molecular weight between crosslinks = Σ (number of moles of each constituent monomer × number average molecular weight of each constituent monomer) / Σ [{(average number of functional groups of each constituent monomer−1) × 2} × each constituent single amount Number of moles of body] (1)

  The polymer crosslinked body (A) can be produced, for example, by using a normal method of polymerizing a (meth) acrylate and / or an epoxy compound using the compound (d) and, if necessary, the monomer (e). it can.

  In the present invention, the linear polymer (B) has a polyether chain (b1). Polyolefin block (f1), polyester block (f2), polyamide block (f3), polyimide block (f4), polyurethane block (f5) and polycarbonate block from the viewpoint of achieving both low elution in the electrolyte and ion conductivity A polyether chain having at least one block (f) selected from the group consisting of (f6) and at least one bond selected from the group consisting of an ester bond, a urethane bond, an amide bond and an imide bond A block having (b1) and at least one selected from the group consisting of polyolefin block (f1), polyester block (f2), polyamide block (f3), polyimide block (f4), polyurethane block (f5) and polycarbonate block (f6) Seed bro Is preferably a click (f) a polymer having a structure combining the (B1).

Examples of the polyether chain (b1) include those obtained by polymerization of alkylene oxides having 2 to 5 carbon atoms.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and the like.
(B1) may be one using an alkylene oxide, or may be a combination of two or more.
When two or more types are used in combination, the coupling type may be either block coupling or random coupling.
Examples of (b1) include a polyoxyethylene chain, a polyoxypropylene chain, and a polyoxyethylene polyoxypropylene chain.
The polyether chain (b1) is preferably a polyoxyethylene chain from the viewpoint of ion conductivity of the protective film.

In the linear polymer (B), the Mn of the polyether chain (b1) is 500 to 5,000, but from the viewpoint of ion conductivity of the protective film and cycle life of the battery, 1,000 to 4, 000 is preferable, and more preferably 1,500 to 3,500.
When the Mn of the polyether chain (b1) is 500 or more, the cycle life characteristics of the battery are improved, and when it is 5,000 or less, the ionic conductivity of the protective film at room temperature can be increased.

The content of the polyether chain (b1) in the linear polymer (B) is preferably 30 to 99% by weight, more preferably, based on the weight of (B), from the viewpoint of ion conductivity of the protective film. Is 50 to 99% by weight.
The content of (b1) in (B) can be determined by ¹ H-NMR.

  As a block having a polyether chain (b1), a polyalkylene glycol (b11) having hydroxyl groups at both ends of the polymer, a polyalkylene glycol amine having a hydroxyl group at one end and an amino group at the other end ( and b12) and polyalkylene glycol diamine (b13) having amino groups at both ends of the polymer.

As the polyolefin block (f1), a polyolefin (f11) having carboxyl groups at both ends of the polymer described in Patent Document 4 (JP 2013-136724 A), a polyolefin (f12) having hydroxyl groups at both ends of the polymer, And polyolefin (f13) having amino groups at both ends of the polymer, polyolefin (f14) having isocyanate groups at both ends of the polymer, polyolefin (f15) having carboxyl groups at one end of the polymer, and hydroxyl groups at one end of the polymer. And polyolefin (f16) having an amino group at one end of the polymer, polyolefin (f18) having an isocyanate group at one end of the polymer, and the like.
These may use 1 type and may use 2 or more types together.
Of these, (f11) and (f15) are preferable from the viewpoint of ease of modification.
By reacting (f11) to (f18) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polyolefin block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

Examples of the polyester block (f2) include carboxyls described in Patent Document 5 (Japanese Patent Laid-Open No. 06-220193), Patent Document 6 (Japanese Patent Laid-Open No. 08-02269) and Patent Document 7 (Japanese Patent Laid-Open No. 2002-121274). Polyester (f21) having groups at both ends of the polymer, polyester (f22) having hydroxyl groups at both ends of the polymer, polyester (f23) having amino groups at both ends of the polymer, and isocyanate groups at both ends of the polymer Polyester (f24), polyester (f25) having a carboxyl group at one end of the polymer, polyester (f26) having a hydroxyl group at one end of the polymer, polyester (f27) having an amino group at one end of the polymer, and isocyanate groups Polyester at one end of polymer Ether (f28), and the like.
These may use 1 type and may use 2 or more types together.
Among these, (f21), (f24) and (f25) are preferable from the viewpoint of ease of modification.
By reacting (f21) to (f28) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polyester block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

As the polyamide block (f3), polyamide (f31) having carboxyl groups at both ends of the polymer described in Patent Document 8 (Japanese Patent Application Laid-Open No. 2011-046941), polyamide (f32) having hydroxyl groups at both ends of the polymer, And polyamide (f33) having amino groups at both ends of the polymer, polyamide (f34) having isocyanate groups at both ends of the polymer, polyamide (f35) having carboxyl groups at one end of the polymer, and hydroxyl groups at one end of the polymer. And polyamide (f36) having an amino group at one end of the polymer, and polyamide (f38) having an isocyanate group at one end of the polymer.
These may use 1 type and may use 2 or more types together.
Of these, (f31), (f34) and (f35) are preferable from the viewpoint of ease of modification.
By reacting (f31) to (f38) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polyamide block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

As the polyimide block (f4), polyimide (f41) having carboxyl groups at both ends of the polymer described in Patent Document 9 (Japanese Patent Laid-Open No. 08-012763) and Patent Document 10 (Japanese Patent Laid-Open No. 2010-202679), Polyimide (f42) having hydroxyl groups at both ends of the polymer, polyimide (f43) having amino groups at both ends of the polymer, polyimide (f44) having isocyanate groups at both ends of the polymer, and carboxyl groups at one end of the polymer Polyimide (f45) having a hydroxyl group at one end of the polymer, polyimide (f47) having an amino group at one end of the polymer, polyimide (f48) having an isocyanate group at one end of the polymer, etc. It is done.
These may use 1 type and may use 2 or more types together.
Of these, (f41), (f44) and (f45) are preferable from the viewpoint of ease of modification.
By reacting (f41) to (f48) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polyimide block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

As the polyurethane block (f5), a polyurethane (f51) having carboxyl groups at both ends of the polymer described in Patent Document 11 (Japanese Patent Application Laid-Open No. 07-062045), a polyurethane (f52) having hydroxyl groups at both ends of the polymer, And polyurethane (f53) having amino groups at both ends of the polymer, polyurethane (f54) having isocyanate groups at both ends of the polymer, polyurethane (f55) having carboxyl groups at one end of the polymer, and hydroxyl groups at one end of the polymer. And polyurethane (f56) having an amino group at one end of the polymer and polyurethane (f58) having an isocyanate group at one end of the polymer.
These may use 1 type and may use 2 or more types together.
Of these, (f51), (f54) and (f55) are preferable from the viewpoint of ease of modification.
By reacting (f51) to (f58) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polyurethane block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

As the polycarbonate block (f6), a polycarbonate (f61) having carboxyl groups at both ends of the polymer described in Patent Document 12 (Japanese Patent Application Laid-Open No. 2007-084552), a polycarbonate (f62) having hydroxyl groups at both ends of the polymer, And a polycarbonate having an amino group at both ends of the polymer (f63), a polycarbonate having an isocyanate group at both ends of the polymer (f64), a polycarbonate having a carboxyl group at one end of the polymer (f65), and a hydroxyl group at one end of the polymer. And polycarbonate (f66) having an amino group at one end of the polymer, and polycarbonate (f68) having an isocyanate group at one end of the polymer.
These may use 1 type and may use 2 or more types together.
Of these, (f61), (f64) and (f65) are preferable from the viewpoint of ease of modification.
By reacting (f61) to (f68) with the block having the polyether chain (b1), the block having the polyether chain (b1) and the polycarbonate block have an ester bond, a urethane bond, A polymer (B1) having a structure bonded through at least one bond selected from the group consisting of an amide bond and an imide bond can be obtained.

In the present invention, the linear polymer (B) has a polyolefin block (f1), a polyamide block (f3), a polyimide block (f4) as the block (f) from the viewpoint of achieving both ionic conductivity and film strength of the protective film. ) And a polyurethane block (f5) are preferred, and a polyolefin block (f1), a polyamide block (f3) and a polyurethane block (f5) are more preferred.
The bond between (b1) and (f) is preferably at least one selected from the group consisting of a urethane bond, an amide bond and an imide bond, more preferably an amide, from the viewpoint of the film strength of the protective film. It is at least one selected from the group consisting of a bond and a urethane bond.

  The Mn of the block (f) is preferably from 100 to 5,000, more preferably from 500 to 2,000, from the viewpoint of achieving both ionic conductivity and film strength of the protective film and the cycle life of the battery.

In the linear polymer (B), it is preferable that (b1) and (f) are alternately repeated from the viewpoint of achieving both ion conductivity and film strength of the protective film.
The number of alternating units {(b1)-(f) or (f)-(b1)} (hereinafter referred to as the number of repetitions) is 2 to 50 from the viewpoint of achieving both ion conductivity and film strength of the protective film. Is more preferable, and 3 to 15 is more preferable.
The number of repetitions is obtained from the following formula (2) from Mn in (b1), Mn in (f), and Mn in (B).
Number of repetitions = {Mn of (B)} / {Mn of (b1) + Mn of (f)} (2)

  The Mn of the linear polymer (B) is preferably 10,000 to 100,000, more preferably 10,000 to 30,000, from the viewpoint of achieving both ionic conductivity and film strength of the protective film. .

Mn in the present invention can be measured under the following conditions using gel permeation chromatography (GPC).
Apparatus (example): “HLC-8120” [manufactured by Tosoh Corporation]
Column (example): “TSKgelGMHXL” (2 pieces)
"TSKgelMultiporeHXL-M" (1 pc.)
Sample solution: 0.3 wt% orthodichlorobenzene solution Solution injection amount: 100 μl
Flow rate: 1 ml / min Measurement temperature: 135 ° C
Detector: Refractive index detector Reference material: Standard polystyrene (TSK standard POLYSTYRENE) 12 points (Molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400) , 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

  The hydroxyl value of the linear polymer (B) is preferably 0 to 5 mgKOH, and more preferably 0 to 1 mgKOH, from the viewpoint of ion conductivity.

In the present invention, the total content of polyether chains in the crosslinked polymer (A) and the linear polymer (B) is 40 to 99% by weight based on the total weight of (A) and (B). However, it is preferably 50 to 80% by weight, more preferably 60 to 75% by weight, from the viewpoint of achieving both ion conductivity and film strength of the protective film.
When the total content of the polyether chains in (A) and (B) is 40% by weight or more, the ion conductivity at normal temperature of the protective film can be increased, and it is 99% by weight or less. The film strength can be increased.
The total content of the polyether chains in (A) and (B) can be measured by solid state NMR. Specifically, it is measured under the following conditions.
<Measurement conditions of solid-state NMR>
Device: ECA400 [manufactured by JEOL Ltd.]
MAS: 6kHz
Measurement: ¹³ C CPMAS
contact time: 2 ms
Accumulation: 10,000 times

In the present invention, the lithium salt (C) includes an inorganic acid lithium salt (C1) and an organic acid lithium salt (C2).
The lithium salt of an inorganic acid _{(C1), LiPF 6, LiBF} 4, LiSbF 6, LiAsF 6 , and LiClO ₄ and the like.
Examples of the lithium salt (C2) of organic acid include LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) _2, LiC (CF ₃ SO ₂ ) _{3 and the} like.
Among (C), from the viewpoint of ion conductivity of the protective film, a lithium salt (C2) of an organic acid is preferable, and LiN (CF ₃ SO ₂ ) ₂ is more preferable.

The content of the crosslinked polymer (A) in the polymer electrolyte composition of the present invention is 2 to 89 on the basis of the weight of the polymer electrolyte composition from the viewpoint of achieving both ionic conductivity and film strength of the protective film. .9% by weight is preferred, more preferably 10-69% by weight.
The content of the linear polymer (B) in the polymer electrolyte composition of the present invention is 10 to 10 based on the weight of the polymer electrolyte composition from the viewpoint of achieving both ionic conductivity and film strength of the protective film. 97.9 weight% is preferable, More preferably, it is 30 to 89 weight%.
The content of the lithium salt (C) in the polymer electrolyte composition of the present invention is preferably 0.1 to 88% by weight based on the weight of the polymer electrolyte composition from the viewpoint of ion conductivity of the protective film, Preferably it is 1 to 60% by weight.
The weight ratio {(A) :( B)} of the crosslinked polymer (A) and the linear polymer (B) in the polymer electrolyte composition of the present invention is determined from the viewpoint of ion conductivity of the protective film. The ratio is preferably 10: 1 to 1:50, more preferably 2: 1 to 1:30.
The weight ratio {polyether chain: (C)} between the polyether chain and the lithium salt (C) in the polymer electrolyte composition of the present invention is 100: 1 to 10: 1 from the viewpoint of ionic conductivity of the protective film. Is preferable, and more preferably 100: 1 to 50: 1.

The polymer electrolyte composition of the present invention may contain inorganic particles (D) in addition to the crosslinked polymer (A), linear polymer (B) and lithium salt (C).
Examples of the inorganic particles (D) include those capable of improving the strength of the protective film. For example, inorganic particles having lithium ion conductivity (lithium oxysulfide, lithium nitride, lithium phosphorous oxynitride, Lithium silicon disulfide, lithium boron disulfide, and a mixture thereof) and inorganic particles having no lithium ion conductivity (SiO ₂ , Al ₂ O ₃ , TiO ₂ , BaTiO _2, Ba ₂ O _{3, and the} like).
The content of the inorganic particles (D) is preferably 0 to 30% by weight, more preferably from the viewpoint of the strength and ion conductivity of the protective film, based on the total weight of (A), (B) and (C). Is 0 to 10% by weight.

A solvent may be further added to the polymer electrolyte composition of the present invention.
Examples of the solvent include ethylene carbonate (ethylene carbonate, EC) and propylene carbonate (propylene carbonate, PC).
The addition amount of the solvent is preferably 0 to 120% by weight, more preferably 0 to 100% by weight with respect to the polymer electrolyte composition from the viewpoint of ion conductivity.

  The polymer electrolyte composition of the present invention can be obtained by mixing the polymer crosslinked body (A), the linear polymer (B), the lithium salt (C), etc. From the viewpoint of achieving both strength and strength, it is preferable to obtain the polymer electrolyte composition according to the present invention described below.

The method for producing a polymer electrolyte composition of the present invention comprises (d) in a monomer solution (X) containing a compound (d) having the following polyether chain (a1) in the presence of a linear polymer (B). It is a manufacturing method of the polymer electrolyte composition including the process of superposing | polymerizing and manufacturing a polymer crosslinked body (A).
Compound (d) having (a1): (meth) acrylate compound (d1) having two or more (meth) acrylate groups and / or epoxy compound (d2) having two or more epoxy groups.
If the polymer electrolyte composition is produced by the production method of the present invention, the linear polymer (B) is dispersed at the molecular level in the polymer crosslinked body (A), and without impairing ionic conductivity, The strength of the protective film can be improved.

The monomer solution (X) may contain a solvent from the viewpoint of handling properties. As a solvent, what is necessary is just to melt | dissolve the compound (d) which has a linear polymer (B) and a polyether chain | strand (a1), For example, toluene, xylene, benzyl alcohol, etc. are mentioned.
The content of the solvent in the monomer solution (X) is preferably 30 to 80% by weight, and more preferably 40 to 60% by weight, from the viewpoint of handling properties.

In the above step, the content of (B) in the monomer solution (X) containing the linear polymer (B) and the compound (d) is based on the weight of (X) from the viewpoint of handling properties. 5-30 weight% is preferable, More preferably, it is 5-15 weight%.
The content of (d) in the monomer solution (X) is preferably 5 to 50% by weight, more preferably 20 to 50% by weight, based on the weight of (X), from the viewpoint of handling properties.

(X) preferably contains a lithium salt (C) from the viewpoint of ion conductivity of the protective film.
The content of (C) in (X) is preferably 0.1 to 88% by weight, more preferably 1 to 88% by weight, based on the total weight of (B), (d), (e) and (C). 60% by weight.

In addition to (B) and (d), the monomer solution (X) may contain another monomer (e), a polymerization initiator (g), and a chain transfer agent (h).
The content of the other monomer (e) is preferably 0 to 10% by weight, more preferably 0 to 5% by weight, based on the weight of (X), from the viewpoint of film strength and handling properties of the protective film. It is.
The content of the polymerization initiator (g) is preferably 0 to 5% by weight, more preferably 0 to 2% by weight, based on the weight of (X), from the viewpoint of film strength and handling properties of the protective film. .
The content of the chain transfer agent (h) is preferably 0 to 5% by weight, more preferably 0 to 2% by weight, based on the weight of (X), from the viewpoint of film strength and handling properties of the protective film. .

The polymerization temperature when polymerizing (d) with heat is preferably from 50 to 150 ° C, more preferably from 50 to 100 ° C, from the viewpoint of ease of production.
The polymerization time is preferably 2 to 10 hours, more preferably 4 to 8 hours, from the viewpoint of the reaction rate.

  As an energy source for curing (d) by light irradiation (light having a wavelength of 360 nm to 830 nm), in addition to a commonly used high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a high power metal halide lamp, and the like (Latest trends in UV / EB curing technology, edited by Radtech Research Institute, CM Publishing, page 138, 2006) can be used. Moreover, the irradiation apparatus using an LED light source can also be used conveniently.

  Moreover, the electron beam irradiation apparatus generally used can be used as an energy source at the time of making it harden | cure by electron beam irradiation.

An example of the manufacturing method of the polymer electrolyte composition of this invention is shown.
(1) A monomer solution (X1) containing a linear polymer (B), a compound (d) and a solvent and, if necessary, a polymerization initiator (g) and / or a chain transfer agent (h) at 50 to 150 ° C. Method of polymerizing (d) with stirring and adding lithium salt (C) to obtain a polymer electrolyte composition (2) Linear polymer (B), compound (d), solvent and lithium salt (C) And, if necessary, a monomer solution (X2) containing a polymerization initiator (g) and / or a chain transfer agent (h) is stirred at 50 to 150 ° C. to polymerize (d) to obtain a polymer electrolyte composition ( 3) Apply the monomer solution (X2) containing the linear polymer (B), the compound (d), the solvent and the lithium salt (C) and, if necessary, the polymerization initiator (g) and / or the chain transfer agent (h). Evaporate the solvent, heat, light and electron beam Among the methods described above for polymerizing at least one member selected from a homogeneous coating easiness to the electrode (lithium metal) surface, (3) is preferable.

  The polymer electrolyte composition of the present invention has high ion conductivity, and a film formed from this has high strength. Therefore, if the polymer electrolyte composition of the present invention is used, a film having high ion conductivity and high strength can be formed on the surface of the lithium metal. Therefore, it is useful as a protective film composition for a lithium metal secondary battery negative electrode. is there.

The negative electrode for a lithium metal secondary battery of the present invention is one in which the negative electrode is coated with the polymer electrolyte composition of the present invention.
The negative electrode includes lithium metal or metal lithium alloy.
The metal lithium alloy can include an element selected from the group consisting of Al, Mg, K, Na, Ca, Sr, Ba, Si, Ge, Sb, Pb, In, and Zn.

The negative electrode for a lithium metal secondary battery is not limited as long as the negative electrode is coated with the polymer electrolyte composition. For example, the monomer solution (X2) is applied to the negative electrode and dried. And at least one selected from the group consisting of electron beams.
The thickness for applying the monomer solution (X2) is preferably 20 to 100 μm, more preferably 20 to 60 μm, from the viewpoint of achieving both ion conductivity and film strength of the protective film.
The drying temperature is the homogeneity of the coating film (= high cycle characteristics) (overvoltage is applied to the non-uniform part of the coating film, which promotes the aggregation and deposition of lithium metal and breaks the electrode protective film) From the viewpoint, the boiling point of the solvent used is preferably ± 30 ° C., more preferably the boiling point of the solvent used is ± 10 ° C.

  In the negative electrode for a lithium metal secondary battery of the present invention, the film thickness of the polymer electrolyte composition is preferably 10 to 50 μm, more preferably 10 to 30 μm, from the viewpoint of achieving both ionic conductivity and film strength of the protective film. is there.

The negative electrode for a lithium metal secondary battery of the present invention may be a part of the negative electrode coated or the whole of the negative electrode, but from the viewpoint of cycle characteristics, 70 to 100% of the total surface area of the negative electrode It is preferable that it is coated, more preferably 95 to 100%.
The covered area can be measured according to the description in Patent Document 13 (Japanese Patent Laid-Open No. 2013-201062) by element mapping in SEM observation and Raman spectroscopic measurement.

  The lithium metal secondary battery of the present invention has the above-described negative electrode for a lithium metal secondary battery of the present invention.

FIG. 1 shows a cross-sectional structure of an example of the lithium metal secondary battery of the present invention. In FIG. 1, 1 is a positive electrode, 2 is a solid electrolyte or solid electrolyte, 3 is a protective film for a negative electrode of a lithium metal secondary battery, and 4 is a negative electrode (lithium metal or metal lithium alloy).
Although not particularly limited, examples of 1 (positive electrode) in FIG. 1 include metal copper (in the case of a lithium-copper battery) and platinum catalyst-supported porous carbon (in the case of a lithium air battery).
2 (solid electrolyte or solid electrolyte) is not particularly limited as long as it is a lithium ion conductor, and examples thereof include a solid electrolyte, an aqueous electrolyte, and a non-aqueous electrolyte.
Examples of the solid electrolyte include inorganic solid electrolytes (LiN, LISICONs, Thio-LISICONs, crystals having a perovskite structure such as La _0.55 Li _0.35 TiO ₃ , LiTi ₂ P ₃ O ₁₂ having a NASICON type structure, and crystallization thereof. Oxide-based electrolyte and sulfide-type electrolyte represented by Li _a M _b P _c S _d ) and organic (polymer) electrolyte (for example, as disclosed in JP 2010-262860 A, fluorine Resin, polyethylene oxide, polyacrylonitrile, polyacrylate and derivatives and copolymers thereof, and materials used as polymer electrolytes).
Examples of the aqueous electrolyte include ethylene glycol and water, and examples of the non-aqueous electrolyte include ethylene carbonate, dimethyl carbonate, propylene carbonate, diethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, and γ- Butyrolactone, tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3 dioxolane, diethyl ether, sulfolane, methylsulfolane, acetonitrile, propionitrile, and a mixture thereof can be used.
Examples of 3 (protective film for lithium metal secondary battery negative electrode) include the above-described protective film for lithium metal secondary battery negative electrode of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these. Hereinafter, unless otherwise specified, “%” means “% by weight” and “part” means “part by weight”.

<Production Example 1: Production of linear polymer (B-1)>
In a pressure-resistant reaction vessel, 176 parts of ε-caprolactam, 23.5 parts of terephthalic acid, 0.4 parts of antioxidant and 11 parts of water were charged, and after nitrogen substitution, pressurized at 220 ° C. (0.2 to 0.3 MPa) The mixture was heated and stirred under sealing for 4 hours to obtain a polyamide (f3-1) having a carboxyl group at both ends (Mn 1,400, acid value 83 mgKOH / g). Next, 150 parts of polyoxyethylene glycol (b1-1) of Mn 2,000, 100 parts of (f3-1) and 1.3 parts of zirconyl acetate were added, and polymerization was performed at 240 ° C. under reduced pressure of 0.13 kPa or less for 5 hours. To give a viscous polymer. This polymer was taken out in a strand form on a belt and pelletized to obtain a linear block polymer (B-1). The Mn of (B-1) was 22,000.

<Production Example 2: Production of linear polymer (B-2)>
In Production Example 1, instead of “150 parts of polyoxyethylene glycol (b1-1) of Mn2,000”, “375 parts of polyoxyethylene glycol (b1-2) of Mn5,000” was used in the same manner. A linear block polymer (B-2) was obtained. Mn of (B-2) was 26,000.

<Production Example 3: Production of linear polymer (B-3)>
In Production Example 1, in place of “150 parts of polyoxyethylene glycol (b1-1) of Mn 2,000”, “290 parts of EO adduct (b1-3) of bisphenol A at both ends of Mn 4,000” was used. Similarly, a linear block polymer (B-3) was obtained. Mn of (B-3) was 24,000.

<Production Example 4: Production of linear polymer (B-4)>
The same procedure as in Production Example 3, except that “87 parts of bisphenol A both-end EO 12 molar adduct (b1-4)” is used instead of “290 parts of bisphenol A both-end EO adduct (b1-3) of Mn4,000”. Thus, a linear block polymer (B-4) was obtained. The Mn of (B-4) was 24,000.

<Production Example 5: Production of linear polymer (B-5)>
In a reaction vessel, 85.0 parts of low molecular weight polypropylene obtained by a thermal degradation method (manufactured by Sanyo Chemical Industries, Ltd., Mn 2,500, density 0.89, “Biscol 660-P”) and maleic anhydride 15. 0 part was melted at 200 ° C. in a nitrogen gas atmosphere and reacted for 20 hours. Thereafter, excess maleic anhydride was distilled off under reduced pressure to obtain acid-modified polypropylene (f1-1).
Next, in another reaction vessel, 100 parts of the obtained (f1-1), 150 parts of polyoxyethylene glycol (b1-1) of Mn2,000 and 1.3 parts of zirconyl acetate were added, Polymerization was performed for 5 hours under a reduced pressure of 0.13 kPa or less to obtain a viscous polymer. This polymer was taken out as a strand on the belt and pelletized to obtain a linear block polymer (B-5). Mn of (B-5) was 26,000.

<Production Example 6: Production of linear polymer (B-6)>
In Production Example 5, instead of “150 parts of polyoxyethylene glycol (b1-1) of Mn 2,000”, “290 parts of EO adduct (b1-3) of bisphenol A at both ends of Mn 4,000” was used. Similarly, a linear block polymer (B-6) was obtained. The Mn of (B-6) was 24,000.

<Production Example 7: Production of linear polymer (B-7)>
In Production Example 5, instead of “150 parts of polyoxyethylene glycol (b1-1) having Mn of 2,000”, “300 parts of polyethylene glycol (b1-5) having both terminal isocyanate groups (NCO content: 3.0%)” A linear block polymer (B-7) was obtained in the same manner except that was used. The Mn of (B-7) was 26,000.
The both-end isocyanate group-modified polyethylene glycol (b1-5) was obtained by reacting 52 parts of polyethylene glycol of Mn 2,000 with 8 parts of 4,4′-diphenylmethane diisocyanate.

<Production Example 8: Production of polyethylene glycol diacrylate 1>
Under nitrogen at 45 ° C., 150 parts of polyethylene glycol (hereinafter referred to as PEG, Mn 2,000, manufactured by Sanyo Chemical Industries, Ltd., “PEG2000”) was dissolved in 400 parts of anhydrous toluene, and PEG-toluene solution did. The PEG-toluene solution was dehydrated by azeotropic distillation at 50 ° C./70 mbar. Acrylyl chloride (8.15 parts) and triethylamine (9.10 parts) were diluted with 40 parts of anhydrous toluene and added dropwise to the PEG-toluene solution. The mixture was stirred at 45-50 ° C. for 4 hours under nitrogen. The reaction mixture was subjected to warm filtration (using “GA-200” manufactured by ADVANTEC, filtered at 60 ° C.) to remove the Et ₃ NHCI salt. Approximately 250 parts of toluene were removed under vacuum (50 ° C., 20 mbar). The remaining solution was kept at 45 ° C. in a heated addition funnel and added dropwise to 800 parts of diethyl ether cooled in an ice bath. PEG diacrylate precipitated as white crystals. After cooling the ether solution for 1 hour, the PEG diacrylate product was obtained by filtration. The product was dried overnight under a vacuum atmosphere (300 mbar, air flow). This procedure yielded 129 parts of an acrylated oligomer (polyethylene glycol diacrylate 1) (82% yield).

<Comparative Production Example 1: Production of linear polymer (B'-1)>
The same procedure as in Production Example 1 was used except that “750 parts of polyoxyethylene glycol (b1′-1) with Mn 10,000” was used instead of “150 parts of polyoxyethylene glycol (b1-1) with Mn 2,000”. Thus, a linear block polymer (B′-1) was obtained. The Mn of (B′-1) was 26,000.

<Comparative Example Production Example 2: Linear Polymer (B′-2)>
Polyethylene glycol dimethyl ether (Mn: 250) was used as the linear polymer (B′-2).

<Comparative Example Production Example 3: Linear Polymer (B′-3)>
Polyethylene glycol (Mn: 1,000,000) was used as the linear polymer (B′-2).

In addition, Mn was measured on condition of the following using gel permeation chromatography (GPC).
Apparatus: “HLC-8120” [manufactured by Tosoh Corporation]
Column: “TSKgelGMHXL” (2)
"TSKgelMultiporeHXL-M" (1 pc.)
Sample solution: 0.3 wt% orthodichlorobenzene solution Solution injection amount: 100 μl
Flow rate: 1 ml / min Measurement temperature: 135 ° C
Detector: Refractive index detector Reference material: Standard polystyrene (TSK standard POLYSTYRENE) 12 points (Molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400) , 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

<Examples 1 to 24>
<Production of Polymer Electrolyte Composition Precursor Solutions (1) to (24)>
Monomer (d) for a crosslinked polymer having a polyether chain (a1) at a predetermined mixing ratio shown in Tables 1 and 2 in toluene, a linear polymer (B) having a polyether chain (b1), lithium The salt (C) and the thermal polymerization initiator (g) were dissolved to obtain polymer electrolyte composition precursor solutions (1) to (24).

<Manufacture of polymer electrolyte composition film>
The polymer electrolyte solutions (1) to (24) thus obtained were applied at 0.0018 g / cm ₂ on a glass plate on which a thickness adjusting spacer (thickness 20 μm) was placed, and then dried at 110 ° C. for 3 hours. It was. Thereafter, the temperature was raised to 150 ° C. and left to stand for 5 hours, and then the film formed on the glass plate was peeled off at 25 ° C. for 1 hour to form a polymer electrolyte composition film (1) comprising the polymer electrolyte composition. To (24) were obtained.
About the obtained polymer electrolyte composition film | membrane (1)-(24), the film thickness was measured with the digital film thickness meter DG-925 [made by Ono Sokki Co., Ltd.]. The results are shown in Tables 1-2.

<Comparative Examples 1-7>
<Production of Polymer Electrolyte Composition Precursor Solutions (1 ′) to (7 ′)>
Monomer (d) for a crosslinked polymer having a polyether chain (a1) at a predetermined blending ratio shown in Table 3 in toluene, a linear polymer (B ′), a lithium salt (C), and a thermal polymerization initiator (G) was melt | dissolved and the polymer electrolyte composition precursor solution (1 ')-(7') for a comparison was obtained.
<Manufacture of polymer electrolyte composition film>
The obtained polymer electrolyte solutions (1 ′) to (7 ′) were applied on a glass plate on which a thickness adjusting spacer (thickness 20 μm) was placed, and then dried at 110 ° C. for 3 hours. Then, after raising the temperature to 150 ° C. and allowing to stand for 5 hours, the film formed on the glass plate was peeled off at 25 ° C. for 1 hour, and the polymer electrolyte composition membranes (1 ′) to ( 7 ′) was obtained.
About the obtained polymer electrolyte composition film | membrane (1 ')-(7'), the film thickness was measured with digital film thickness meter DG-925 [made by Ono Sokki Co., Ltd.]. The results are shown in Table 3.

In Tables 1 to 3, the following components were used.
Polyethylene glycol diacrylate 1: Obtained in Production Example 8 Polyethylene glycol diacrylate 2: Shin-Nakamura Chemical Co., Ltd., “A-600”
Ethoxylated bisphenol A diacrylate 1: “A-BPE-30” manufactured by Shin-Nakamura Chemical Co., Ltd.
Ethoxylated bisphenol A diacrylate 2: “ABE-300” manufactured by Shin-Nakamura Chemical Co., Ltd.
2,2′-azobis (2-methylbutyronitrile): “V-59” manufactured by Wako Pure Chemical Industries, Ltd.
LiN (CF ₃ SO ₂ ) ₂ : manufactured by Kishida Chemical Co., Ltd.

The EO content in the compounds in Tables 1 to 3 was measured under the following conditions using ¹ H-NMR.
<Measurement conditions for ¹ H-NMR>
Equipment: AVANCE300 (manufactured by Nippon Bruker Co., Ltd.)
Frequency: 300MHz

  The obtained polymer electrolyte membranes (1) to (24) and (1 ') to (7') were evaluated for ion conductivity and coating strength by the following test methods.

<Ion conductivity evaluation>
Each polymer electrolyte composition film was sandwiched between platinum plates, the AC impedance between the electrodes was measured, and a complex impedance analysis was performed. As a measuring instrument, an impedance analyzer (model: 4192A) manufactured by Yokogawa Hewlett-Packard Co. is used. The measurement conditions are applied voltage = 10 mV, measurement frequency = 5 Hz to 13 MHz, measurement temperature = 25 ° C. did. The results are shown in Tables 1-3.

<Evaluation of coating strength>
The tensile strength of each polymer electrolyte membrane was measured according to JIS L1096-1990 using a Tensilon universal testing machine. The size of the test piece was 50 mm wide × 200 mm long (measured length). The results are shown in Tables 1-3.

<Creation of negative electrode for lithium metal secondary battery>
The polymer electrolyte composition precursor solutions (1) to (24) and (1 ′) to (7 ′) of Examples 1 to 24 and Comparative Examples 1 to 7 were used as lithium metal (vertical 20 mm × width 30 mm × thickness). 50 μm) The coating was applied to the entire surface at 0.0045 g / cm ² and then dried at 110 ° C. for 3 hours. Thereafter, the temperature was raised to 150 ° C. and left to stand for 5 hours, whereby the negative electrodes (1) to (24) for lithium metal secondary batteries coated with the polymer electrolyte composition (protective film) and the lithium metal for comparison were used. Negative electrodes (1 ′) to (7 ′) for secondary batteries were obtained.
<Measurement of coating area>
The obtained negative electrodes for lithium metal secondary batteries (1) to (24) and (1 ′) to (7 ′) were subjected to SEM observation and elemental mapping in Raman spectroscopic measurement. The covering area was measured in accordance with the description. The results are shown in Tables 1-3.

A lithium metal battery cell was obtained according to the following procedure. The electrolytic solution used was ethylene carbonate / diethyl carbonate (50 wt% / 50 wt%) in which 1 M LiN (CF ₃ SO ₂ ) ₂ was dissolved.
(Procedure of positive electrode)
As the positive electrode active material, activated carbon having a specific surface area of about 2200 m ₂ / g obtained by an alkali activation method was used. Activated carbon powder, acetylene black, and polyvinylidene fluoride are mixed at a weight ratio of 80:10:10, and this mixture is added to N-methylpyrrolidone as a solvent, and mixed by stirring to form a slurry. Got. This slurry was applied onto an aluminum foil having a thickness of 30 μm by a doctor blade method, temporarily dried, and then cut so that the electrode size was 20 mm × 30 mm. The electrode thickness was about 50 μm.
(Battery preparation procedure)
A separator (nonwoven fabric made of polypropylene) is inserted between the positive electrode and the negative electrodes for lithium metal secondary batteries (1) to (24) and (1 ′) to (7 ′), respectively, and impregnated with an electrolytic solution. The lithium metal secondary batteries (1) to (24) and (1 ′) to (7 ′) were prepared by sealing them in a storage case made of a laminate film.

<Evaluation of room temperature charge / discharge cycle characteristics>
About the obtained lithium metal secondary batteries (1) to (24) and (1 ′) to (7 ′), a charge / discharge measuring device “Battery Analyzer 1470 type” [manufactured by Toyo Technica Co., Ltd.] at room temperature of 25 ° C. The battery was charged to a voltage of 4.3 V with a current of 0.1 C, and after a pause of 10 minutes, the battery voltage was discharged to 3.0 V with a current of 0.1 C, and this charge / discharge was repeated. At this time, the battery capacity at the first charge and the battery capacity at the 50th cycle charge were measured, and the charge / discharge cycle characteristics were calculated from the following formula. It shows that charging / discharging cycling characteristics are so favorable that a numerical value is large.
Room temperature charge / discharge cycle characteristics (%) = (battery capacity at the 50th cycle charge / battery capacity at the first charge) × 100

From the results of Tables 1 to 3, Comparative Example 1 using 10,000 or 1,000,000 whose Mn of the polyether chain (b1) in the linear polymer is outside the upper limit of the present invention. The polymer electrolyte composition films of 3, 4, 6, and 7 had low ionic conductivity at 25 ° C. Moreover, the lithium ion secondary battery using the polymer electrolyte composition film of Comparative Examples 2 and 5 in which Mn of the polyether chain (b1) is outside the lower limit range of the present invention has low charge / discharge cycle characteristics.
On the other hand, the polymer electrolyte composition films of the present invention in Examples 1 to 24 had high ion conductivity. Furthermore, the lithium metal secondary battery using the negative electrode for a lithium metal secondary battery coated with this polymer electrolyte composition film had high room temperature charge / discharge cycle characteristics. Therefore, it can be seen that by using the polymer electrolyte composition of the present invention, it is possible to form a protective film excellent in high ion conductivity at room temperature and cycle life characteristics of the battery.

  The polymer electrolyte composition of the present invention can provide a protective film for a negative electrode of a lithium metal secondary battery excellent in high ion conductivity at room temperature. Moreover, if the lithium metal secondary battery negative electrode coat | covered with the polymer electrolyte composition of this invention is used, the lithium metal secondary battery excellent in the recycling life characteristic can be obtained.

1: Positive electrode 2: Solid electrolyte or solid electrolyte 3: Protective film for lithium metal secondary battery negative electrode 4: Negative electrode

Claims (11)

A polymer electrolyte composition containing a crosslinked polymer (A) having a polyether chain (a1), a linear polymer (B) having a polyether chain (b1), and a lithium salt (C),
The number average molecular weight of (a1) is 100 to 5,000, the number average molecular weight of (b1) is 500 to 5,000, and the total content of the polyether chains in (A) and (B) is ( A polymer electrolyte composition which is 40 to 99% by weight based on the total weight of A) and (B). The linear polymer (B) has a block having a polyether chain (b1), a polyolefin block (f1), a polyester block (f2), a polyamide block (f3), a polyimide block (f4), and a polyurethane block (f5). And at least one block (f) selected from the group consisting of polycarbonate blocks (f6), and through at least one bond selected from the group consisting of ester bonds, urethane bonds, amide bonds and imide bonds. The polymer electrolyte composition according to claim 1, wherein the polymer electrolyte composition is a polymer (B1) having a structure in which a block having a polyether chain (b1) and (f) are combined. The polymer electrolyte composition according to claim 2, wherein the number average molecular weight of the block (f) is 100 to 5,000. The crosslinked polymer (A) comprises a compound (d) having a polyether chain (a1) as an essential constituent monomer, and (d) is a (meth) acrylate compound having two or more (meth) acrylate groups ( The polymer electrolyte composition according to claim 1, which is d1) and / or an epoxy compound (d2) having two or more epoxy groups. The polymer electrolyte composition according to any one of claims 1 to 4, wherein the polyether chain (a1) is a polyoxyethylene chain. The polymer electrolyte composition according to any one of claims 1 to 5, wherein the polyether chain (b1) is a polyoxyethylene chain. The weight ratio {(A) :( B)} of the crosslinked polymer (A) and the linear polymer (B) is 10: 1 to 1:50. The polymer electrolyte composition. Based on the weight of the polymer electrolyte composition, the content of the crosslinked polymer (A) is 2 to 89.9% by weight, the content of the linear polymer (B) is 10 to 97.9% by weight, lithium Content of salt (C) is 0.1-88 weight%, The polymer electrolyte composition in any one of Claims 1-7. A negative electrode for a lithium metal secondary battery, which is coated with the polymer electrolyte composition according to claim 1. The lithium metal secondary battery which has a negative electrode for lithium metal secondary batteries of Claim 9. A method for producing the polymer electrolyte composition according to claim 1,
A step of producing a crosslinked polymer (A) by polymerizing (d) in a monomer solution (X) containing a linear polymer (B) and a compound (d) having the following polyether chain (a1): The manufacturing method of the polymer electrolyte composition containing.
Compound (d) having (a1): (meth) acrylate compound (d1) having two or more (meth) acrylate groups and / or epoxy compound (d2) having two or more epoxy groups.

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