JP2013196993A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery having high capacity and excellent cycle charge/discharge characteristics.SOLUTION: A positive electrode whose material surface is covered with a composition for a polymer solid electrolyte containing a polyether copolymer and an electrolyte salt compound contains a compound having a phenol structure with both of ortho positions substituted with a tert-butyl group, and a secondary battery having high capacity and excellent cycle charge/discharge characteristics is obtained by employing the positive electrode subjected to heat treatment for the secondary battery before application of a potential.

Description

  The present invention relates to a nonaqueous electrolyte secondary battery comprising a positive electrode material, a negative electrode material, and a nonaqueous electrolyte, and more specifically, a phenol structure in which both of the ortho positions are substituted with tert-butyl groups. The present invention relates to a non-aqueous electrolyte secondary battery that has a high capacity and excellent cycle charge / discharge characteristics by using a positive electrode that contains a compound having a heat treatment and is subjected to a heat treatment before applying a potential.

  Conventionally, a non-aqueous electrolyte secondary battery represented by a lithium ion battery has been used in the form of a solution or a paste from the viewpoint of ionic conductivity. However, since there is a risk of equipment damage due to liquid leakage, various safety measures are necessary, which is a barrier to the development of large batteries.

  In contrast, solid electrolytes such as inorganic crystalline substances, inorganic glasses, and organic polymer substances have been proposed. However, although the inorganic electrolyte has high ionic conductivity, it is difficult to increase the size of the battery because the electrolyte is crystalline or amorphous and it is difficult to reduce the volume change due to the positive and negative electrode active materials during charge and discharge. On the other hand, organic polymer materials are generally expected to progress in terms of excellent flexibility, bending workability, and moldability, and increasing the degree of freedom in the design of applied devices.

  If the organic polymer solid electrolyte can be combined with positive and negative electrode materials conventionally used in lithium ion batteries, it is possible to develop a large battery having higher safety. However, good characteristics have not been reported so far for batteries using the above positive and negative electrode materials and polymer electrolyte.

  For example, as a previous report regarding a combination of a lithium ion conductive polymer (polymer electrolyte) and a positive electrode layered compound, Patent Document 1 discloses that a positive electrode surface is formed using an inorganic material for the purpose of suppressing deterioration of an organic electrolyte located near the positive electrode. Are protected, and this has been reported to improve cycle life. However, when 50 cycles have elapsed, the discharge capacity has decreased to 60% of the initial capacity, and there has been a problem with respect to the cycle life.

  Attempts to add a radical scavenger such as an antioxidant into the positive electrode have been studied as a suppression of oxidative degradation of the organic electrolyte. Patent Documents 2 and 3 describe a general phenol-based antioxidant as a radical scavenger, but the phenol-based oxidation has a hydroxyl group that is soluble in an electrolyte and reactive with Li ions. It is considered difficult to control the inhibitor and exert its effect.

JP 2003-338321 A Japanese Patent Laid-Open No. 10-162809 JP-A-11-67211

  In view of the circumstances as described above, an object of the present invention is to provide a secondary battery having high capacity and excellent cycle charge / discharge characteristics.

As a result of intensive studies to solve the above problems, the present inventors have found that the positive electrode whose surface of the positive electrode material is covered with the composition for a polymer solid electrolyte containing a polyether copolymer and an electrolyte salt compound is in the ortho position. Both of these include a compound having a phenol structure substituted with a tert-butyl group, and a positive electrode that has been heat-treated before applying a potential is employed in a secondary battery, thereby enabling high-capacity cycle charge / discharge. The inventors have found that a secondary battery having excellent characteristics can be obtained, and have completed the present invention.
In general, the surface to be covered is the main surface, in particular one main surface. In this specification, the “main surface” means a surface in contact with the solid electrolyte. The “main surface” is generally a plane (surface) having the largest area in the negative electrode material or the positive electrode material.

  That is, the present invention has been completed based on the above knowledge, and the positive electrode whose surface of the positive electrode material is covered with the composition for a polymer solid electrolyte comprising the following components (i) and (ii) is in the ortho position. Provided is a method for producing a non-aqueous electrolyte secondary battery using a positive electrode that includes a compound having a phenol structure, both of which are substituted with a tert-butyl group, and that has been heat-treated before applying a potential.

で示される単量体から誘導される繰り返し単位９５〜５モル％、および
式（２）：

[式中、Ｒは炭素数１〜１２のアルキル基、または−ＣＨ_２Ｏ（ＣＲ^１Ｒ^２Ｒ^３）である。Ｒ^１、Ｒ^２、Ｒ^３は、同一または異なって、水素原子または−ＣＨ_２Ｏ（ＣＨ_２ＣＨ_２Ｏ）_ｎＲ^４であり、ｎおよびＲ^４はＲ^１、Ｒ^２、Ｒ^３の間で異なっていても良い。Ｒ^４は炭素数１〜１２のアルキル基、置換基を有していてもよいアリール基であり、ｎは０〜１２の整数である。]
で示される単量体から誘導される繰り返し単位５〜９５モル％、および
式（３）：

［式中、Ｒ⁵はエチレン性不飽和基を含有する基を表す］
で示される単量体から誘導される繰り返し単位０〜２０モル％を有する重量平均分子量が１０^４〜１０^７の範囲内であるポリエーテル共重合体と
（ii）電解質塩化合物
を含む高分子固体電解質によって正極材料の表面が覆われた正極が、
（iii）オルト位の２つともがｔｅｒｔ−ブチル基に置換されているフェノール構造を有する化合物
を含有し、正極の熱処理を行っていることを特徴とする非水電解質二次電池。 Item 1.
(I) Formula (1):

And 95 to 5 mol% of repeating units derived from the monomer represented by formula (2):

[Wherein, R represents an alkyl group having 1 to 12 carbon atoms, or —CH ₂ O (CR ¹ R ² R ³ ). R ¹ , R ² and R ³ are the same or different and are a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O) _n R ⁴ , and n and R ⁴ are between R ¹ , R ² and R ³ . May be different. R ⁴ is an alkyl group having 1 to 12 carbon atoms and an aryl group which may have a substituent, and n is an integer of 0 to 12. ]
5 to 95 mol% of repeating units derived from the monomer represented by formula (3):

[Wherein R ⁵ represents a group containing an ethylenically unsaturated group]
A polymer solid comprising a polyether copolymer having 0 to 20 mol% of repeating units derived from the monomer represented by formula (II) and a weight average molecular weight in the range of 10 ⁴ to 10 ⁷ and (ii) an electrolyte salt compound A positive electrode whose surface is covered with an electrolyte
(Iii) A nonaqueous electrolyte secondary battery comprising a compound having a phenol structure in which both of the ortho positions are substituted with a tert-butyl group, and performing heat treatment of the positive electrode.

Item 2.
A step of applying a solid polymer electrolyte containing a compound having a phenol structure in which both of the ortho positions are substituted with tert-butyl groups on the electrode of the positive electrode material, or both of the ortho positions are tert-butyl The nonaqueous electrolyte secondary battery according to claim 1, wherein the nonaqueous electrolyte secondary battery is produced in a step of applying a positive electrode material containing a compound having a phenol structure substituted on a group onto a current collector.

Item 3.
Compounds having a phenol structure in which both of the ortho positions are substituted with a tert-butyl group are 2,6-di-tert-butyl-phenol and 2,6-di-tert-butyl-4-methylphenol. 2,6-di-tert-butyl-4-ethylphenol, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4- Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, tetrakis [methylene-3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate] methane, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], Tadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4- Hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, or isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate. The nonaqueous electrolyte secondary battery according to claim 1 or 2.

Item 4.
4. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 3, wherein the electrolyte salt compound is a lithium salt compound.
The non-aqueous electrolyte secondary battery according to claim 1, wherein an aprotic organic solvent is further added to the polymer solid electrolyte composition.

Item 6.
6. The nonaqueous electrolyte secondary battery according to claim 5, wherein the aprotic organic solvent is selected from the group consisting of ethers and esters.
Item 7.
The non-aqueous electrolyte secondary battery according to claim 1, wherein the heat treatment is performed within a temperature range of 50 ° C. or higher and 150 ° C. or lower.

Item 8.
The positive electrode material is AMO ₂ (A is an alkali metal, M is a single or two or more transition metals, and a part thereof may include a non-transition metal), AM ₂ O ₄ (A is an alkali metal, M Consists of a single or two or more transition metals, part of which may contain a non-transition metal), A ₂ MO ₃ (A is an alkali metal, M is a single or two or more transition metals, A part thereof may contain a non-transition metal), AMBO ₄ (A is an alkali metal, B is P, Si, or a mixture thereof, M is a single or two or more transition metals, and a part thereof is non- The nonaqueous electrolyte secondary battery according to any one of claims 1 to 7, wherein the nonaqueous electrolyte secondary battery has a composition of any one of (which may contain a transition metal).

  According to the present invention, the positive electrode whose surface of the positive electrode material is covered with the polymer solid electrolyte composition includes a compound having a phenol structure in which both of the ortho positions are substituted with tert-butyl groups, and By applying heat treatment to the positive electrode before applying the potential, a non-aqueous electrolyte secondary battery having a high capacity and excellent cycle charge / discharge characteristics can be provided.

  Hereinafter, the configuration of the present invention will be described in detail.

  The compound of formula (1) is ethylene oxide. The compound of the formula (1) is a basic chemical product, and a commercially available product is easily available.

The compound of the formula (2) can be easily synthesized by obtaining it from a commercial product or by a general ether synthesis method from epihalohydrin and alcohol. Examples of commercially available compounds include propylene oxide, butylene oxide, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, tertiary butyl glycidyl ether, benzyl glycidyl ether, 1,2-epoxide decane, 1,2 -Epoxy octane, 1,2-epoxyheptane, 2-ethylhexyl glycidyl ether, 1,2-epoxydecane, 1,2-epoxyhexane, glycidyl phenyl ether, 1,2-epoxypentane, glycidyl isopropyl ether, etc. can be used. . Among these commercially available products, propylene oxide, butylene oxide, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, and glycidyl isopropyl ether are preferable, and propylene oxide, butylene oxide, methyl glycidyl ether, and ethyl glycidyl ether are particularly preferable. In the monomer represented by the formula (2) obtained by synthesis, R is preferably —CH ₂ O (CR ¹ R ² R ³ ), and at least one of R ¹ , R ² , and R ³ is —CH ₂ O. it is preferably _{(CH 2 CH 2 O) n} R 4. R ⁴ is preferably an alkyl group having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. n is preferably from 2 to 6, and more preferably from 2 to 4.

In the compound of the formula (3), an example of R ⁵ may be a hydrocarbon group having a double bond, in particular, a cyclic hydrocarbon group having a double bond, or CH ₂ ═CH—A ¹ — ( A ¹ may be a direct bond or a hydrocarbon group having 1 to 30 carbon atoms, such as an alkylene group.
The compound of the formula (3) can be easily synthesized from a commercially available product or by a general ether synthesis method from epihalohydrin and alcohol. For example, allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpinyl glycidyl ether, cyclohexenyl methyl glycidyl ether, p-vinylbenzyl glycidyl ether, allyl phenyl glycidyl ether, vinyl glycidyl ether, 3,4-epoxy-1 -Butene, 3,4-epoxy-1-pentene, 4,5-epoxy-2-pentene, 1,2-epoxy-5,9-cyclododecadiene, 3,4-epoxy-1-vinylcyclohexene, 1, 2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate, glycidyl crotonate, glycidyl-4-hexenoate, among these allyl glycidyl ether, Alkenyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate are preferred.

（Ｂ）：式（２）の単量体から誘導された繰り返し単位：

（Ｃ）：式（３）の単量体から誘導された繰り返し単位：

[式中、Ｒは炭素数１〜１２のアルキル基、または−ＣＨ_２Ｏ（ＣＲ^１Ｒ^２Ｒ^３）である。Ｒ^１、Ｒ²、Ｒ^３は、同一または異なって、水素原子または−ＣＨ_２Ｏ（ＣＨ_２ＣＨ_２Ｏ）_ｎＲ^４であり、ｎおよびＲ⁴はＲ^１、Ｒ²、Ｒ³の間で異なっていても良い。Ｒ^４は炭素数１〜１２のアルキル基であり、ｎは０〜１２の整数である。Ｒ⁵はエチレン性不飽和基を含有する基を表す。]
を有する。 The polyether copolymer (i) of the present invention is
(A): Repeating unit derived from the monomer of formula (1):

(B): Repeating unit derived from the monomer of formula (2):

(C): Repeating unit derived from the monomer of formula (3):

[Wherein, R represents an alkyl group having 1 to 12 carbon atoms, or —CH ₂ O (CR ¹ R ² R ³ ). R ¹ , R ² , and R ³ are the same or different and are a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O) _n R ⁴ , and n and R ⁴ are between R ¹ , R ² , and R ³ . May be different. R ⁴ is an alkyl group having 1 to 12 carbon atoms, and n is an integer of 0 to 12. R ⁵ represents a group containing an ethylenically unsaturated group. ]
Have

R is preferably —CH ₂ O (CR ¹ R ² R ³ ), and at least one of R ¹ , R ² and R ³ is preferably —CH ₂ O (CH ₂ CH ₂ O) _n R ⁴ . R ⁴ is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms. n is preferably from 2 to 6, and more preferably from 2 to 4.

The synthesis of the polyether copolymer (i) of the present invention can be performed as follows. Coordination anion initiator such as catalyst system mainly composed of organic aluminum, catalyst system mainly composed of organic zinc, organotin-phosphate ester condensate catalyst system as a ring-opening polymerization catalyst, or potassium containing K ⁺ as a counter ion By using an anionic initiator such as alkoxide, diphenylmethyl potassium, potassium hydroxide, and the like, each of the monomers is reacted in the presence or absence of a solvent at a reaction temperature of 10 to 120 ° C. with stirring to obtain a polyether copolymer. can get. From the viewpoint of the degree of polymerization or the properties of the resulting copolymer, a coordination anion initiator is preferred, and an organotin-phosphate ester condensate catalyst system is particularly preferred because of ease of handling.

  In the polyether copolymer (i) of the present invention, the molar ratio of the repeating units (A), (B), and (C) is (A) 95-5 mol%, (B) 5-95 mol%. And (C) 0-20 mol% is suitable, preferably (A) 92-10 mol%, (B) 7-90 mol%, and (C) 1-15 mol%, more preferably (A) ) 90-20 mol%, (B) 10-80 mol%, and (C) 2-15 mol%. If the repeating unit (A) exceeds 95 mol%, the glass transition temperature rises and the oxyethylene chain crystallizes, resulting in a marked deterioration in the ionic conductivity of the solid electrolyte. In general, it is known that ion conductivity is improved by reducing the crystallinity of polyethylene oxide, but the polyether copolymer of the present invention is remarkably superior in this respect.

The molecular weight of the polyether copolymer (i) of the present invention is within the range of a weight average molecular weight of 10 ⁴ to 10 ⁷ , preferably 5 × 10 ⁴ to 5 in order to obtain good processability, mechanical strength and flexibility. within 5 × 10 ⁶ range, more preferably suitable are those of ¹⁰ 5 to 5 × 10 ⁶ range. A copolymer having a weight average molecular weight of less than 10 ⁴ needs to have a high cross-linking density in order to enhance shape stability, so that only a plastic form can be obtained, there is almost no elongation, and ionic conductivity is low. . A copolymer having a weight average molecular weight of more than 10 ⁷ has remarkably poor processability and is difficult to handle.

  The polyether copolymer (i) of the present invention may be a copolymer type of either a block copolymer or a random copolymer. Random copolymers are preferred because they have a greater effect of reducing the crystallinity of polyethylene oxide.

  In order to suppress a short circuit between the electrodes, it is preferable to interpose a crosslinked polymer solid electrolyte between the electrodes. Cross-linked solid polymer electrolytes include, for example, a method of attaching a pre-cross-linked solid polymer electrolyte membrane between electrodes, a polymer solid electrolyte containing a radical polymerization initiator on the surface of the negative electrode, It can be introduced by the method of applying. The thickness of the crosslinked polymer solid electrolyte interposed between the electrodes may generally be 0.1 μm to 400 μm.

  The crosslinked polymer solid electrolyte of the present invention comprises a polymer solid electrolyte in the presence of an electrolyte salt compound in a composition for a polymer solid electrolyte containing a polyether copolymer and a radical polymerization initiator, and an aprotic organic solvent. In the presence or absence of, it is a crosslinked product crosslinked by applying heat or irradiating active energy rays such as ultraviolet rays.

  In the case of crosslinking by heat, a radical polymerization initiator selected from organic peroxides, azo compounds and the like is used. As organic peroxides, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxy esters, etc., which are usually used for crosslinking are used. As azo compounds, azonitriles are used. A compound, an azoamide compound, an azoamidine compound, or the like that is usually used for crosslinking is used. The amount of radical polymerization initiator added varies depending on the type, but is usually in the range of 0.1 to 10% by weight with respect to 100% by weight of the polyether copolymer (i).

  As the radical polymerization initiator in the case of crosslinking that irradiates active energy rays, alkylphenone-based, benzophenone-based, acylphosphine oxide-based, titanocenes, triazines, bisimidazoles, oxime esters, and the like are used. The amount of these radical polymerization initiators to be added varies depending on the type, but is usually in the range of 0.01 to 5.0% by weight with respect to 100% by weight of the polyether copolymer (i).

In the present invention, a crosslinking aid may be used when the composition for a polymer solid electrolyte is crosslinked. Crosslinking aid is usually polyfunctional compound - a _{(e.g., CH 2 = CH-, CH 2} = CH-CH 2, CF 2 = CF- at least two containing compound).

  The electrolyte salt compound (ii) that can be used in the present invention is preferably compatible with a mixture comprising a polyether copolymer or a crosslinked product of the copolymer and, if necessary, an aprotic organic solvent. Here, “compatible” means a state where the electrolyte salt does not precipitate due to crystallization.

The electrolyte salt compound (ii) of the present invention is preferably a lithium salt compound, and in particular, a cation lithium ion and a chlorine ion, bromine ion, iodine ion, perchlorate ion, thiocyanate ion, tetrafluoroborate ion, Nitrate ion, AsF ₆ ⁻ , PF ₆ ⁻ , B (C ₂ O ₂ ) ₂ ⁻ , stearyl sulfonate ion, octyl sulfonate ion, dodecylbenzene sulfonate ion, naphthalene sulfonate ion, dodecyl naphthalene sulfonate ion, 7, 7,8,8-tetracyano-p-quinodimethane ion, X ₁ SO ₃ ⁻ , [(X ₁ SO ₂ ) (X ₂ SO ₂ ) N] ⁻ , [(X ₁ SO ₂ ) (X ₂ SO ₂ ) (X ₃ SO ₂ ) C] ⁻ , and an anion selected from [(X ₁ SO ₂ ) (X ₂ SO ₂ ) YC] ⁻ . _{However, X 1, X 2, X} 3 and Y is an electron withdrawing group. Preferably, X ₁ , X ₂ and X ₃ are each independently a perfluoroalkyl group or a perfluoroaryl group having 1 to 6 carbon atoms, and Y is a nitro group, a nitroso group, a carbonyl group, a carboxyl group or It is a cyano group. X ₁ , X ₂ , and X ₃ may be the same or different from each other.

  In the present invention, the amount of the electrolyte salt compound used is preferably 0.0001 to 5, more preferably 0.001 to 5 in terms of the number of moles of the electrolyte salt compound / the total number of moles of ether oxygen atoms in the polyether copolymer. A range of 0.5 is good.

  In the present invention, an aprotic organic solvent may be added as a plasticizer, for example. When an aprotic organic solvent is mixed in the polymer solid electrolyte, the crystallization of the polymer is suppressed, the glass transition temperature is lowered, and many amorphous phases are formed even at a low temperature, so that the ionic conductivity is improved. The aprotic organic solvent is suitable for obtaining a high-performance battery having a low internal resistance by combining with the solid polymer electrolyte that can be used in the present invention. The polymer solid electrolyte of the present invention may be gelled by combining with an aprotic organic solvent. Here, the gel is a polymer swollen by a solvent.

  As the aprotic organic solvent, aprotic ethers and esters are preferable. Specifically, propylene carbonate, γ-butyrolactone, butylene carbonate, vinyl carbonate, ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl monoglyme, methyl diglyme, methyl triglyme, methyl tetraglyme, ethyl monoglyme , Ethyl diglyme, ethyl triglyme, ethyl methyl monoglyme, butyl diglyme, 3-methyl-2-oxazolidone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4,4-methyl-1,3-dioxolane , Methyl formate, methyl acetate, methyl propionate, etc., among them, propylene carbonate, γ-butyrolactone, butylene carbonate, vinyl carbonate, Ji Ren carbonate, methyl triglyme, methyl tetraglyme, ethyl triglyme, ethyl methyl monoglyme preferred. These can be used alone or in combination of two or more.

  There is no particular limitation on the method of mixing the electrolyte salt compound and the necessary aprotic organic solvent into the polyether copolymer, but the polyether copolymer is long in the solution containing the electrolyte salt compound and the necessary aprotic organic solvent. Method of soaking by impregnation for a period of time, method of mechanically mixing electrolyte salt compound and necessary aprotic organic solvent into polyether copolymer, dissolving polyether copolymer and electrolyte salt compound in aprotic organic solvent Or a method in which the polyether copolymer is once dissolved in another solvent and then mixed with an aprotic organic solvent. Other polar solvents such as tetrahydrofuran, acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, methyl isobutyl ketone, etc. used alone or in combination are used as other solvents in the case of producing using other solvents. It is done. Other solvents can be removed before, during or after cross-linking the polyether copolymer.

  The compound (iii) having a phenol structure in which both of the ortho positions which can be used in the present invention are substituted with a tert-butyl group is generally commercially available as an antioxidant, and 2,6-di- tert-butyl-phenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 1,6-hexanediol-bis [3- (3 5-Di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3 5-triazine, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2,2-thio-diethylenebis [3- 3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3 , 5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2, 4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, or isooctyl-3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate. These can be used alone or in combination of two or more.

  The method for adding the compound (iii) having a phenol structure in which both of the ortho positions of the present invention are substituted with a tert-butyl group is not particularly limited, but a positive electrode containing a compound having a phenol structure on a current collector From the viewpoint of uniformity, it is preferable to add a compound having a phenol structure by applying a slurry of the material or by applying a solution of a composition for a polymer solid electrolyte containing a compound having a phenol structure on the positive electrode. .

  The addition amount of the compound (iii) having a phenol structure in which both of the ortho positions of the present invention are substituted with tert-butyl groups is obtained by adding a slurry of a positive electrode material containing a compound having a phenol structure on a current collector. When applied, the positive electrode material is 100% by weight, preferably 0.1% by weight or more and 20% by weight or less. When applying a solution of a composition for a polymer solid electrolyte containing a compound having a phenol structure on the positive electrode, The content of the polymer solid electrolyte composition is preferably 100% by weight and preferably 0.1% by weight to 20% by weight. When the content is 0.1% by weight or more and 20% by weight or less, battery characteristics are improved.

  The positive electrode material is, for example, a metal electrode substrate as an electrode material substrate, a positive electrode active material on the metal electrode substrate, and a good ion exchange with the electrolyte layer, and the conductive auxiliary agent and the positive electrode active material are fixed to the metal substrate. It is made up of a binder. For example, aluminum is used for the metal electrode substrate, but is not limited thereto, and may be nickel, stainless steel, gold, platinum, titanium, or the like.

The positive electrode active material particles used in the present invention are alkali metal-containing composite oxide powders having a composition of any one of LiMO ₂ , LiM ₂ O ₄ , Li ₂ MO ₃ , and LiMBO ₄ . M consists of a single transition metal or two or more transition metals, and a part thereof may contain a non-transition metal. B consists of P, Si, or a mixture thereof. The particle diameter of the positive electrode active material particles is preferably 50 μm or less, more preferably 20 μm or less, for example, 0.1 to 15 μm. These active materials have an electromotive force of 3 V (vs. Li / Li +) or more.

Preferred examples of the positive electrode active material include Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x CrO ₂ , Li _x FeO ₂ , Li _x Co _a Mn _1-a O ₂ , Li _x Co _a Ni _1-a O ₂ , Li _x Co _a Cr _1-a O ₂ , Li _x Co _a Fe _1-a O ₂ , Li _x Co _a Ti _1-a O ₂ , Li _x Mn _a Ni _1-a O ₂ , Li _x Mn _a Cr _1-a O ₂ , Li _x Mn _a Fe _1-a O ₂ , Li _x Mn _a Ti _1-a O ₂ , Li _x Ni _a Cr _1-a O ₂ , Li _x Ni _a Fe _1-a O ₂ , Li _x Ni _a Ti _1-a O ₂ , Li _x Cr _a Fe _1-a O ₂ , Li _x Cr _a Ti _1-a O ₂ , Li _x Fe _a Ti _1-a O ₂ , Li _x Co _b Mn _c Ni _1-bc O ₂ , Li _x Cr _b Mn _c Ni _1-bc O ₂ , Li _x Fe _b Mn _c Ni _1-bc O ₂ , Li _x Ti _b Mn _c Ni _1-bc O ₂ , Li _x Mn ₂ O ₄ , Li _x Mn _d Co _2-d O ₄ , Li _x Mn _d Ni _2-d O ₄ , Li _x Mn _d Cr _2-d O ₄ , Li _x Mn _d Fe _2-d O ₄ , Li _x Mn _d Ti _2-d O ₄ , Li _y MnO ₃ , Li _y Mn _e Co _1-e O ₃ , Li _y Mn _e Ni _1-e O ₃ , Li _y Mn _e Fe _1-e O _{3, Li y Mn e Ti 1} -e O 3, Li x CoPO 4, Li x MnPO 4, Li x NiPO 4, Li x FePO 4, Li x Co f Mn 1-f PO 4, Li x Co f Ni 1 _-f PO ₄ , Li _x Co _f Fe _1-f PO ₄ , Li _x Mn _f Ni _1-f PO ₄ , Li _x Mn _f Fe _1-f PO ₄ , Li _x Ni _f Fe _1-f PO ₄ , Li _y CoSiO ₄ , Li _y MnSiO ₄ , Li _y NiSiO ₄ , Li _y FeSiO ₄ , Li _y Co _g Mn _1-g SiO ₄ , Li _y Co _g Ni _1-g SiO ₄ , Li _y Co _g Fe _1-g SiO ₄ , Li _y Mng _g Ni _1-g SiO ₄ , Li _y Mng _g Fe _1-g SiO ₄ , Li _y Ni _g Fe _1-g SiO ₄ , Li _y CoP _h Si _{1 -h} O ₄ , Li _y MnP _h Si _1-h O ₄ , Li _y NiP _h Si _1-h O ₄ , Li _y FeP _h Si _1-h O ₄ , Li _y Co _g Mn _1-g P _h Si _{1 -h O 4, Li y Co g} Ni 1-g P h Si 1-h O 4, Li y Co g Fe 1-g P h Si 1-h O 4, Li y Mn g Ni 1-g P h Si It is mentioned _{1-h O 4, Li y} Mn g Fe 1-g P h Si 1-h O 4, Li y Ni g Fe 1-g P h Si 1-h O 4 lithium-containing composite oxides such as it can. (Where x = 0.01 to 1.2, y = 0.01 to 2.2, a = 0.01 to 0.99, b = 0.01 to 0.98, c = 0.01 to 0.98 where b + c = 0.02 to 0.99, d = 1.49 to 1.99, e = 0.01 to 0.99, f = 0.01 to 0.99, g = 0 .01-0.99, h = 0.01-0.99.)

Among the preferable positive electrode active materials, more preferable positive electrode active materials include, specifically, Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x CrO ₂ , Li _x Co _a Ni _{1- a} O ₂ , Li _x Mn _a Ni _1-a O ₂ , Li _x Co _b Mn _c Ni _1-bc O ₂ , Li _x Mn ₂ O ₄ , Li _y MnO ₃ , Li _y Mn _e Fe _1-e O _{3 , Li y Mn e Ti 1-} e O 3, Li x CoPO 4, Li x MnPO 4, Li x NiPO 4, Li x FePO 4, Li x Mn f Fe 1-f PO 4, it can be mentioned. (Where x = 0.01 to 1.2, y = 0.01 to 2.2, a = 0.01 to 0.99, b = 0.01 to 0.98, c = 0.01 to 0.98 where b + c = 0.02 to 0.99, d = 1.49 to 1.99, e = 0.01 to 0.99, and f = 0.01 to 0.99. The values of x and y increase or decrease due to charge / discharge.)

  The negative electrode material is, for example, a metal electrode substrate as an electrode material substrate, a negative electrode active material on the metal electrode substrate, and exchange of good ions with the electrolyte layer, and the conductive auxiliary agent and the negative electrode active material are fixed to the metal substrate It is made up of a binder. In this case, for example, copper is used for the metal electrode substrate, but the metal electrode substrate is not limited to this, and may be nickel, stainless steel, gold, platinum, titanium, or the like.

  The negative electrode active material used in the present invention is a carbon material (natural graphite, artificial graphite, amorphous carbon, etc.) having a structure (porous structure) capable of occluding and releasing alkali metal ions such as lithium ions, lithium, or the like. It is a powder made of a metal such as lithium, an aluminum compound, a tin compound, or a silicon compound that can occlude and release alkali metal ions such as ions. The particle diameter is preferably from 10 nm to 100 μm, more preferably from 20 nm to 20 μm. Moreover, you may use as a mixed active material of a metal and a carbon material. It is preferable to use a negative electrode active material having a porosity of 40 to 90%, particularly about 70%.

  A positive electrode active material and a negative electrode active material are mixed together with a conductive additive, a binder, a thickener, and the like with a solvent to form a slurry. Examples of the conductive assistant include conductive carbon such as acetylene black, ketjen black, carbon fiber, and graphite, conductive polymer, and metal powder, and conductive carbon is particularly preferable. These conductive agents are added in an amount of 20% by weight or less, preferably 15% by weight or less, for example, 0.01 to 10% by weight based on 100% by weight of the active material. As the binder, for example, at least one compound selected from a fluorine-based binder, acrylic rubber, modified acrylic rubber, styrene-butadiene rubber, acrylic polymer, and vinyl polymer can be used. In addition, it is preferable to use an acrylic polymer because oxidation resistance, sufficient adhesion with a small amount, and flexibility in the electrode plate can be obtained. These binders are added in an amount of 100% by weight of the active material, preferably 5% by weight or less, more preferably 3% by weight or less, for example, 0.01 to 2% by weight. Examples of the thickener include carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose and the like, or alkali metal salts thereof, polyethylene oxide and the like. These thickeners are added in an amount of 100% by weight of the active material, preferably 5% by weight or less, more preferably 3% by weight or less, for example, 0.01 to 2% by weight.

  Formation of the positive electrode active material powder and the negative electrode active material powder on the metal electrode substrate is performed by a doctor blade method, a silk screen method, or the like.

  For example, in the doctor blade method, a negative electrode active material powder or a positive electrode active material powder is dispersed in water or an organic solvent such as n-methylpyrrolidone to form a slurry, which is applied to a metal electrode substrate, and then a blade having a predetermined slit width. Uniform to an appropriate thickness. The electrode is dried in a vacuum state, for example, at 50 to 130 ° C. (especially at 80 ° C.) in order to remove excess solvent after applying the active material. An electrode material is manufactured by press-molding the dried electrode with a pressing device.

  Thereafter, a polymer solid electrolyte is applied to the main surface of the electrode material using, for example, a doctor blade method. The polymer solid electrolyte is mixed with a solvent such as acetonitrile according to its viscosity, applied after adjusting to an appropriate viscosity, allowed to stand as necessary, and impregnated with a polymer solid electrolyte solution in the porous portion, This may be heated and dried. The thickness of the coating layer after drying the solvent (polymer solid electrolyte) is preferably 400 μm or less, more preferably 200 μm or less, particularly 0.1 to 150 μm.

  The method for adding the compound (iii) having a phenol structure in which both of the ortho positions of the present invention are substituted with a tert-butyl group is not particularly limited, but a slurry-like positive electrode material containing a compound having a phenol structure is used. From the viewpoint of uniformity, it is preferable to apply a compound having a phenol structure by applying it to a metal electrode substrate or by applying a solid polymer electrolyte solution containing a compound having a phenol structure to the surface of the positive electrode material.

  In the present invention, the positive electrode is heat-treated before the potential is applied. A method for heat-treating a positive electrode containing a compound having a phenol structure in which the surface is covered with a solid polymer electrolyte and both ortho-positions are substituted with tert-butyl groups is not particularly limited. It is preferable to heat-treat in the state which exposed the polymer solid electrolyte surface in inert gas atmosphere. The temperature of the heat treatment is preferably in the range of 50 ° C. or higher and 150 ° C. or lower. Heat treatment can be carried out industrially efficiently at a heat treatment temperature in the range of 50 ° C. to 150 ° C. without causing oxidative decomposition of the organic material. The heat treatment time varies depending on the temperature, but is usually within 10 days, for example, 10 minutes to 48 hours.

  A non-aqueous electrolyte secondary battery is assembled by superimposing a negative electrode and a positive electrode coated with a polymer solid electrolyte. At this time, when the thickness or mechanical strength of the applied polymer solid electrolyte is insufficient, it is preferable to interpose a crosslinked polymer solid electrolyte between the electrode materials. The crosslinked polymer solid electrolyte can be introduced by a technique in which a separately prepared crosslinked polymer solid electrolyte membrane is interposed between the electrodes, or a technique in which the polymer solid electrolyte disposed on the negative electrode surface is crosslinked.

  When evaluating the characteristics of only the positive electrode material, the reversibility of the electrode material can be evaluated by using a lithium sheet for the counter electrode. In the case of evaluating the combination of the positive electrode material and the negative electrode material, a combination of the positive electrode material and the carbon-based negative electrode material is used without using the lithium sheet.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples described below as long as the gist of the invention is not exceeded.

EXAMPLES Specific modes for carrying out the present invention will be described below with reference to examples. However, the present invention is not limited to the following examples.

  In this example, the following experiment was conducted to compare reversible capacity and cycle performance in a nonaqueous electrolyte secondary battery composed of a positive electrode material, a nonaqueous electrolyte, and a negative electrode material.

[Synthesis Example (Production of Polyether Copolymer Catalyst)]
In a three-necked flask equipped with a stirrer, thermometer and distillation apparatus, 10 g of tributyltin chloride and 35 g of tributyl phosphate are added and heated at 250 ° C. for 20 minutes with stirring under a nitrogen stream to distill off the distillate. As a product, a solid condensate was obtained. It used as a polymerization catalyst in the following polymerization examples.

The monomer equivalent composition of the polyether copolymer was determined by ¹ H NMR spectrum.
For measuring the molecular weight of the polyether copolymer, gel permeation chromatography (GPC) measurement was performed, and the weight average molecular weight was calculated in terms of standard polystyrene. GPC measurement was performed at 60 ° C. using RID-6A manufactured by Shimadzu Corporation, Showdex KD-807, KD-806, KD-806M and KD-803 columns manufactured by Showa Denko KK, and DMF as a solvent. .

１５０ｇ、及び溶媒としてｎ−ヘキサン１０００ｇを仕込み、化合物（ａ）の重合率をガスクロマトグラフィーで追跡しながら、エチレンオキシド１５０ｇを逐次添加した。このときの重合温度は２０℃とし、１０時間反応を行った。重合反応はメタノールを１ｍＬ加え反応を停止した。デカンテーションによりポリマーを取り出した後、常圧下４０℃で２４時間、更に減圧下４５℃で１０時間乾燥してポリマー２８０ｇを得た。得られたポリエーテル共重合体の重量平均分子量およびモノマー換算組成分析結果を表１に示す。 [Polymerization Example 1]
The inside of a glass four-necked flask having an internal volume of 3 L was purged with nitrogen, and 1 g of the condensate shown in the synthesis example of the catalyst as a polymerization catalyst and a glycidyl ether compound (a) adjusted to a water content of 10 ppm or less:

150 g of n-hexane was charged as a solvent and 150 g of ethylene oxide, and 150 g of ethylene oxide was sequentially added while monitoring the polymerization rate of the compound (a) by gas chromatography. The polymerization temperature at this time was 20 ° C., and the reaction was carried out for 10 hours. The polymerization reaction was stopped by adding 1 mL of methanol. After taking out the polymer by decantation, it was dried at 40 ° C. under normal pressure for 24 hours and further under reduced pressure at 45 ° C. for 10 hours to obtain 280 g of polymer. Table 1 shows the weight average molecular weight and monomer conversion composition analysis results of the obtained polyether copolymer.

[Polymerization Example 2]
The inside of a glass four-necked flask having an internal volume of 3 L is purged with nitrogen, and 1 g of the condensate shown in the synthesis example of the catalyst as a polymerization catalyst and 150 g of glycidyl ether compound (a) adjusted to a water content of 10 ppm or less, allyl glycidyl ether 30 g and n-hexane 1000 g were charged as a solvent, and 150 g of ethylene oxide was successively added while monitoring the polymerization rate of the compound (a) by gas chromatography. The polymerization temperature at this time was 20 ° C., and the reaction was carried out for 10 hours. The polymerization reaction was stopped by adding 1 mL of methanol. After taking out the polymer by decantation, it was dried at 40 ° C. under normal pressure for 24 hours and further at 45 ° C. under reduced pressure for 10 hours to obtain 290 g of polymer. Table 1 shows the weight average molecular weight and monomer conversion composition analysis results of the obtained polyether copolymer.

[Polymerization Example 3]
The inside of a glass four-necked flask having an internal volume of 3 L is purged with nitrogen, and as a polymerization catalyst, 1 g of the condensate shown in the synthesis example of the catalyst, 75 g of glycidyl ether compound (a) adjusted to a water content of 10 ppm or less, a chain transfer agent As a solvent, 0.5 g of ethylene glycol monomethyl ether and 500 g of toluene as a solvent were added, and 150 g of ethylene oxide was sequentially added while monitoring the polymerization rate of the compound (a) by gas chromatography. The polymerization temperature at this time was 20 ° C., and the reaction was carried out for 10 hours. The polymerization reaction was stopped by adding 1 mL of methanol. The reaction solution was poured into 2000 g of n-hexane, and the polymer was taken out by decantation and washing, and then dried at 40 ° C. under normal pressure for 24 hours and further at 45 ° C. for 10 hours under reduced pressure to obtain 200 g of polymer. Table 1 shows the weight average molecular weight and monomer conversion composition analysis results of the obtained polyether copolymer.

[Crosslinking example 1]
1.0 g of the polyether copolymer obtained in Polymerization Example 2, 0.002 g of photoinitiator benzophenone,
Crosslinking aid N, N′-m-phenylenebismaleimide 0.05 g, and molar ratio (number of moles of electrolyte salt compound) / (total number of moles of ether oxygen atoms in the copolymer) is 0.05. A solution of bis (trifluoromethanesulfonyl) imide lithium dissolved in 10 ml of acetonitrile was applied onto a polyethylene terephthalate film using a 500 μm gap bar coater, heated to 80 ° C. and dried as it was, and then the electrolyte surface was laminated film A crosslinked polymer electrolyte membrane was prepared by irradiating with a high-pressure mercury lamp (30 mW / cm ² ) for 30 seconds in the state covered with 1.

Example 1 Fabrication of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium LiCo _1/3 Mn _1/3 Ni _1/3 O ₂ with an average particle size of 10 μm was used as the positive electrode active material. . With respect to 10.0 g of this positive electrode active material, 0.5 g of spherical carbon fine particles produced by thermal decomposition of acetylene as a conductive assistant, 0.1 g of styrene-butadiene rubber (SBR) as a binder, and carboxy as a thickener 0.2g of methylcellulose sodium salt (CMC) was added, and after stirring for 1 hour using a stainless ball mill with water as a solvent, it was coated on an aluminum current collector using a bar coater with a 50 μm gap, and in a vacuum state at 80 ° C. Then, after 12 hours or more, it was roll-pressed to obtain a positive electrode sheet.
Further, 1.0 g of the polyether copolymer obtained in Polymerization Example 1, 0.05 g of 2,6-di-tert-butyl-4-methylphenol, and molar ratio (number of moles of electrolyte salt compound) / (copolymerization) A solution prepared by dissolving lithium borofluoride in 10 ml of acetonitrile so that the total number of moles of ether oxygen atoms in the coalescence was 0.05 was applied onto the above positive electrode sheet using a bar coater with a gap of 500 μm, and kept at 80 ° C. The polymer electrolyte composition is thoroughly impregnated in the positive electrode sheet and dried, followed by heat treatment at 100 ° C. for 12 hours in an argon gas atmosphere, so that the polymer electrolyte is integrated on the positive electrode sheet. A positive electrode / electrolyte sheet was prepared.
In the glove box substituted with argon gas, the cross-linked polymer electrolyte membrane obtained in the cross-linking example 1 was bonded to the positive electrode / electrolyte sheet, and metal lithium was bonded as a counter electrode to assemble a test 2032 type coin cell. . The electrochemical characteristics were measured using a charging / discharging device manufactured by Hokuto Denko Co., Ltd., under the test conditions (C / 4) where predetermined charging and discharging can be performed in 4 hours, with 4.2 V as the upper limit and 2.5 V as the lower limit. The positive electrode was evaluated by applying a constant current. The test temperature was 60 ° C. environment. The test results are shown in Table 2.

Example 2 Production of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium Instead of 2,6-di-tert-butyl-4-methylphenol, tetrakis [methylene-3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate] A positive electrode / electrolyte sheet was produced in the same manner as in Example 1 except that methane was used. To this, metallic lithium was bonded as a counter electrode to prepare a coin battery, and the electrochemical characteristics of the positive electrode were evaluated. The test results are shown in Table 2.

[Example 3] Production of battery composed of positive electrode material / solid polymer electrolyte / metallic lithium 1,3,5-trimethyl-2,4 instead of 2,6-di-tert-butyl-4-methylphenol A positive electrode / electrolyte sheet was prepared in the same manner as in Example 1 except that, 6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene was used. To this, metallic lithium was bonded as a counter electrode to prepare a coin battery, and the electrochemical characteristics of the positive electrode were evaluated. The test results are shown in Table 2.

[Comparative Example 1] Production of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium No 2,6-di-tert-butyl-4-methylphenol was added at the time of production of positive electrode / electrolyte sheet and at 100 ° C. A coin battery was prepared in the same manner as in Example 1 except that the heat treatment was not performed, and the electrochemical characteristics of the positive electrode were evaluated. The test results are shown in Table 2.

Comparative Example 2 Production of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium A coin battery was prepared in the same manner as in Example 1 except that no heat treatment was performed at 100 ° C. when producing the positive electrode / electrolyte sheet. It produced and evaluated the electrochemical characteristic of the positive electrode. The test results are shown in Table 2.

[Comparative Example 3] Preparation of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium Instead of the polyether copolymer obtained in Polymerization Example 1, the polyether copolymer obtained in Polymerization Example 3 was used. A positive electrode / electrolyte sheet was produced in the same manner as in Example 1 except for the above. To this, metallic lithium was bonded as a counter electrode to prepare a coin battery, and the electrochemical characteristics of the positive electrode were evaluated. The test results are shown in Table 2.

Comparative Example 4 Fabrication of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Metal Lithium 4,4′-Butylidenebis (3-methyl-) Instead of 2,6-Di-tert-butyl-4-methylphenol A positive electrode / electrolyte sheet was prepared in the same manner as in Example 1 except that 6-t-butylphenol was used, and a coin battery was prepared by laminating metal lithium as a counter electrode, and the electrochemical characteristics of the positive electrode were evaluated. The test results are shown in Table 2.

[Example 4] Production of Battery Consisting of Positive Electrode Material / Polymer Solid Electrolyte / Negative Electrode Material As a negative electrode active material, graphite powder (porous structure material) having an average particle diameter of 12 μm was used. To 10.0 g of this negative electrode active material, 0.5 g of carbon fiber synthesized at 2000 ° C. or more as a conductive auxiliary agent, 0.1 g of SBR as a binder, 0.2 g of CMC as a thickener are added, and water is added. After stirring for 1 hour using a stainless ball mill as a solvent, it was coated on a copper current collector using a 50 μm gap bar coater, dried at 80 ° C. in a vacuum state for 12 hours or more, and then roll pressed to form a negative electrode sheet did.
Further, 1.0 g of the polyether copolymer obtained in Polymerization Example 1 and a molar ratio (number of moles of electrolyte salt compound) / (total number of moles of ether oxygen atoms in the copolymer) are set to 0.05. A solution obtained by dissolving bis (trifluoromethanesulfonyl) imide lithium in 10 ml of acetonitrile is applied onto the above negative electrode sheet using a 500 μm gap bar coater, heated to 80 ° C. as it is, and a polymer electrolyte is formed on the negative electrode sheet. An integrated negative electrode / electrolyte sheet was prepared.
In a glove box substituted with argon gas, the positive electrode / electrolyte sheet obtained in Example 1 was bonded to the cross-linked polymer electrolyte membrane obtained in Cross-Linking Example 1, and the negative electrode / electrolyte sheet was further bonded to the coin as a counter electrode. I assembled the battery. Electrochemical characteristics were charged and discharged using a charging / discharging device. Under the test conditions (C / 4) where predetermined charging and discharging can be performed in 4 hours, the upper limit was 4.2 V, the lower limit was 2.5 V, and positive and negative electrodes were applied with constant current. Was evaluated. The test temperature was 60 ° C. environment. The test results are shown in Table 3.

[Comparative Example 5] Production of Battery Constructed by Positive Electrode Material / Polymer Solid Electrolyte / Negative Electrode Material A battery was prepared and the electrochemical characteristics of the positive electrode and the negative electrode were evaluated. The test results are shown in Table 3.

  The nonaqueous electrolyte secondary battery of the present invention has a high capacity and excellent cycle charge / discharge characteristics. The battery of the present invention can be used as a stationary battery for load leveling.

Claims (8)

(I) Formula (1):

And 95 to 5 mol% of repeating units derived from the monomer represented by formula (2):

[Wherein, R represents an alkyl group having 1 to 12 carbon atoms, or —CH ₂ O (CR ¹ R ² R ³ ). R ¹ , R ² and R ³ are the same or different and are a hydrogen atom or —CH ₂ O (CH ₂ CH ₂ O) _n R ⁴ , and n and R ⁴ are between R ¹ , R ² and R ³ . May be different. R ⁴ is an alkyl group having 1 to 12 carbon atoms and an aryl group which may have a substituent, and n is an integer of 0 to 12. ]
5 to 95 mol% of repeating units derived from the monomer represented by formula (3):

[Wherein R ⁵ represents a group containing an ethylenically unsaturated group]
A polymer solid comprising a polyether copolymer having 0 to 20 mol% of repeating units derived from the monomer represented by formula (II) and a weight average molecular weight in the range of 10 ⁴ to 10 ⁷ and (ii) an electrolyte salt compound A positive electrode whose surface is covered with an electrolyte
(Iii) A nonaqueous electrolyte secondary battery comprising a compound having a phenol structure in which both of the ortho positions are substituted with a tert-butyl group, and performing heat treatment of the positive electrode.   A step of applying a solid polymer electrolyte containing a compound having a phenol structure in which both of the ortho positions are substituted with tert-butyl groups on the electrode of the positive electrode material, or both of the ortho positions are tert-butyl The nonaqueous electrolyte secondary battery according to claim 1, wherein the nonaqueous electrolyte secondary battery is produced in a step of applying a positive electrode material containing a compound having a phenol structure substituted on a group onto a current collector.   Compounds having a phenol structure in which both of the ortho positions are substituted with a tert-butyl group are 2,6-di-tert-butyl-phenol and 2,6-di-tert-butyl-4-methylphenol. 2,6-di-tert-butyl-4-ethylphenol, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4- Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, tetrakis [methylene-3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate] methane, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], Tadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4- Hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, or isooctyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate. The nonaqueous electrolyte secondary battery according to claim 1 or 2.   The nonaqueous electrolyte secondary battery according to claim 1, wherein the electrolyte salt compound is a lithium salt compound. The non-aqueous electrolyte secondary battery according to claim 1, wherein an aprotic organic solvent is further added to the polymer solid electrolyte composition.   6. The nonaqueous electrolyte secondary battery according to claim 5, wherein the aprotic organic solvent is selected from the group consisting of ethers and esters.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the heat treatment is performed within a temperature range of 50 ° C. or higher and 150 ° C. or lower. The positive electrode material is AMO ₂ (A is an alkali metal, M is a single or two or more transition metals, and a part thereof may include a non-transition metal), AM ₂ O ₄ (A is an alkali metal, M Consists of a single or two or more transition metals, part of which may contain a non-transition metal), A ₂ MO ₃ (A is an alkali metal, M is a single or two or more transition metals, A part thereof may contain a non-transition metal), AMBO ₄ (A is an alkali metal, B is P, Si, or a mixture thereof, M is a single or two or more transition metals, and a part thereof is non- The nonaqueous electrolyte secondary battery according to any one of claims 1 to 7, wherein the nonaqueous electrolyte secondary battery has a composition of any one of (which may contain a transition metal).