JP6787461B1 - Battery composition and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for a battery capable of achieving excellent battery characteristics without deteriorating battery performance due to a short circuit or the like even if a metallic foreign substance such as copper is mixed in, and an application thereof. is there. SOLUTION: The general formula is cyanuric acid, isocyanuric acid, allantuitone, barbituric acid, 1,3,5-triazinan-2,4-dione, glutarimide, hydantoin, uric acid, or a derivative thereof ( A battery composition comprising any of the compounds 1) to (8) and a conductive auxiliary agent and / or a solvent, and a battery mixture film and battery electrode using the same. It will be solved by the next battery. [Selection diagram] None

Description

The present invention relates to a battery composition, which comprises adding a compound having a specific structure. Specifically, the present invention relates to cyanuric acid and isocyanuric acid having a specific structure in a battery composition made of a carbon material which is a conductive auxiliary agent. , Allantoin, barbituric acid, 1,3,5-triazinan-2,4-dione, glutarimide, hydantoin, uric acid, or compounds of the general formulas (1) to (8) which are derivatives of each. By doing so, the present invention relates to a lithium secondary battery that does not deteriorate in performance due to a short circuit or the like even if a metal, particularly copper foreign matter, is mixed in.

In recent years, small portable electronic devices such as digital cameras and mobile phones have come into widespread use. These electronic devices are constantly required to have a minimum volume and a light mass, and the batteries to be mounted are also required to be compact, lightweight, and have a large capacity. Further, in a large secondary battery for automobile mounting and the like, it is desired to realize a large non-aqueous electrolyte secondary battery instead of the conventional lead storage battery.

In order to meet such demands, lithium secondary batteries are being actively developed. The electrodes of the lithium secondary battery include a positive electrode in which an electrode mixture composed of a positive electrode active material containing lithium ions, a conductive auxiliary agent, and an organic binder is fixed to the surface of a metal foil current collector, and lithium ion removal. A negative electrode is used in which an electrode mixture composed of an insertable negative electrode active material, a conductive auxiliary agent, an organic binder, or the like is fixed to the surface of a current collector of a metal foil.

Lithium secondary batteries have problems related to safety such as deterioration of battery performance due to reduction / precipitation of metal components on the negative electrode, excessive heat generation due to short circuit, and ignition. Factors of performance deterioration and short circuit due to metal components include (1) mixing of metal impurities such as copper and iron in the manufacturing process, and (2) metal ions contained in the positive electrode, current collector, battery container, etc. in the electrolytic solution. It is conceivable that the metal ions are reduced and precipitated on the negative electrode after being eluted from the positive electrode, and (3) metal ions are eluted from the positive electrode active material due to deterioration of the positive electrode and reduced and precipitated on the negative electrode. With regard to metals with magnetism such as iron, even if they are mixed, they can be recovered by the magnetic sorting process, etc., and deterioration of battery performance and short circuit can be prevented, but they cannot be recovered by magnetic sorting such as copper. It is difficult to remove metal after mixing with metal foreign matter.

Various additives have been studied in order to suppress the elution of copper ions into the electrolytic solution when a copper foreign substance is mixed and the precipitation of the foreign substance on the negative electrode. Patent Document 1 proposes an alkaline battery in which a chelating agent such as EDTA is blended with a positive electrode mixture of the alkaline battery. In the present invention, by adding a chelating agent to the positive electrode mixture, an attempt is made to complex copper ions even when copper, which is a heavy metal impurity, is ionized from manganese dioxide in the positive electrode mixture. ing. However, since the chelating agent diffuses through the electrolytic solution and captures the ionized active material by chelate formation, the capacity of the active material is reduced, so that the discharge capacity is reduced.

Further, Patent Document 2 proposes a non-aqueous battery in which benzotriazole or a derivative thereof is present in the non-aqueous battery container. In the present invention, an attempt is made to improve the performance of a non-aqueous battery by treating not only the electrolytic solution but also the electrode (particularly the negative electrode). However, even if it is added to the electrolytic solution and the electrode mixture by the method shown in the present invention, it acts on the active material and captures / inactivates them as in Patent Document 1, so that the capacity of the active material is reduced. Therefore, the discharge capacity is reduced. In addition, since the additive acts on the active material, it is inevitable that the battery performance will be deteriorated by the copper foreign matter mixed in the system.

Further, Patent Document 3 proposes a composition for a battery containing an organic dye derivative that imparts a function of capturing metal ions to a conductive auxiliary agent. In the present invention, the acidic functional group of the organic dye derivative exerts the effect of capturing metal ions in the electrolytic solution. However, since the acidic functional group of the organic dye derivative has a great influence on the wettability of the carbon material, which is a conductive additive, to the solvent, the balance between the dispersibility and stability of the dispersion itself is lost depending on the amount of metal. Therefore, this invention is insufficient.

Japanese Unexamined Patent Publication No. 2008-21497 Japanese Unexamined Patent Publication No. 6-349523 International Publication No. 2008/108360 Pamphlet

In view of the above circumstances, the present invention provides a battery composition capable of achieving excellent battery characteristics without deteriorating battery performance due to a short circuit or the like even if a metallic foreign substance such as copper is mixed in, and its use. Is an issue.

As a result of diligent studies to solve the above problems, the present inventors have made a battery performance that does not deteriorate due to a short circuit or the like even if a metal foreign substance is mixed in by adding a compound having a specific structure to the battery composition. They have found that an excellent battery can be realized, and have come up with the present invention.

That is, the present invention is a group consisting of compounds represented by the following general formulas (1) , (3) and (4) , conductive aids and / or solvents , ammonia, ammonium salts, amine compounds and inorganic bases. The present invention relates to a composition for an electrode of a lithium ion secondary battery , which comprises at least one selected from the above .
General formula (1)



One general formula (3)


General formula (4)


[In general formulas (1) , (3), (4),
X _{1 and} X ₂ may independently have an alkoxy group, a halogen atom, and a substituent.
It represents a reel group, a hydroxyl group or -OCOR, where R represents an alkyl group which may have a substituent or an aryl group which may have a substituent.
Y ₇ is hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom.
Y ₃ to Y ₆ are each independently hydrogen, an optionally substituted alkyl group, an aryl group or a halogen atom which may have a substituent, at least one is hydrogen.
R ₁ and R ₂ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, a hydroxyl group, a nitro group or an amino group, respectively. ]

The present invention further relates to an electrode composition of the lithium ion secondary battery, which further comprises a binder component.

The present invention further relates to an electrode composition of the lithium ion secondary battery, which further comprises a positive electrode active material or a negative electrode active material.

Further, the present invention comprises compounds represented by the general formulas (1), (3) and (4), at least one selected from the group consisting of ammonia, ammonium salts, amine compounds and inorganic bases, and positive electrode activity. The present invention relates to a mixture film for an electrode of a lithium ion secondary battery, which comprises a substance or a negative electrode active material .

Further, the present invention is on an electrode substrate, an electrode for mixture film of a lithium ion secondary battery comprising comprises a mixture film for the battery.

The present invention also relates to a lithium ion secondary battery provided with the battery electrode.

The details of the present invention will be described below. In the present specification, "N-methyl-2-pyrrolidone" is "NMP", "positive electrode active material or negative electrode active material" is "electrode active material" or "active material", and "battery containing active material and binder". "Composition for battery" may be abbreviated as "mixture slurry for batteries", "mixture slurry" or "mixture composition".

<Compounds represented by general formulas (1) to (8)>
The battery composition of the present invention contains at least one selected from the group consisting of the compounds represented by the following general formulas (1) to (8).

General formula (1)


General formula (2)


General formula (3)

General formula (4)

General formula (5)

General formula (6)


General formula (7)


General formula (8)

X _{1 and} X ₂ independently represent an alkoxy group, a halogen atom, an aryl group which may have a substituent, a hydroxyl group or −OCOR, and R is an alkyl group or a substituent which may have a substituent. Represents an aryl group which may have.
Y ₁ , Y _2, Y _{7, and} Y ₁₃ are each independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom.
Y ₃ to Y ₆ are each independently hydrogen, an optionally substituted alkyl group, an aryl group or a halogen atom which may have a substituent, at least one is hydrogen.
Y _{8 to} Y ₁₀ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom, and at least one of them is hydrogen.
Y ₁₁ and Y ₁₂ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom, and at least one of them is hydrogen.
R _{1 to} R ₁₆ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, a hydroxyl group, a nitro group or an amino group, respectively.

Cyanuric acid and its derivatives are represented by the general formula (1), isocyanuric acid and its derivatives are represented by the general formula (2), uric acid and its derivatives are represented by the general formula (3), barbituric acid and its derivatives. Is represented by the general formula (4), 1,3,5-triazinan-2,4-dione and its derivatives are represented by the general formula (5), and glutarimide and its derivatives are represented by the general formula (6). , Hydantin and its derivatives are represented by the general formula (7), and allantin and its derivatives are represented by the general formula (8).

In X _{1 and} X ₂ , examples of the alkoxy group include a linear or branched-chain alkoxy group. Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a tert-butoxy group and the like. The number of carbon atoms of the alkoxy group is preferably in the range of 1 to 6, and more preferably in the range of 1 to 3.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine.

Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the alkyl group include a linear or branched alkyl group. Specific examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, isopentyl group, 2-ethylhexyl group, sec-butyl group and tert-butyl. Groups, sec-pentyl groups, tert-pentyl groups and the like can be mentioned. The number of carbon atoms of the alkyl group is preferably in the range of 1 to 6, and more preferably in the range of 1 to 3.

The "substituted group" of the alkyl group and the aryl group which may have a substituent may be the same or different, and specific examples thereof include a hydroxy group, a halogen atom such as fluorine, chlorine and bromine, a nitro group and an alkyl. Examples thereof include a group, an aryl group, a cycloalkyl group, an alkoxyl group, an aryloxy group, an alkylthio group, an arylthio group and the like. Further, there may be a plurality of these substituents.

The same structure as described above can be mentioned for Y _{1 to} Y ₁₃ and R _{1 to} R ₁₆ .

Specific examples of the compounds represented by the general formulas (1) to (8) are shown in Table 1.

Compounds A to P and a to w coexist with tautomers due to tautomerism. For example, compound A and compound C are tautomers. The place where the compound is present is preferably a positive electrode or a negative electrode in which a metal foreign substance such as copper is present. Although details are unknown, all of the above compounds have a nitrogen atom and have keto-enol tautomerism. It is considered that the strong action on metallic foreign substances such as copper can suppress the elution of copper ions that cause a battery short circuit.

The method of allowing the above compound to exist in the positive electrode or the negative electrode is not particularly limited, and examples thereof include a method of mixing the carbon material as a conductive auxiliary agent at the time of dispersion. In addition, a method of mixing when the binder component is added and a method of mixing when the active material is added can be mentioned.
The metal foreign matter is not particularly limited, and examples thereof include metals, metal oxides, alloys such as brass and bronze, and copper is a typical metal. Further, the existence state and the mixing route of the metallic foreign matter are not particularly limited. For example, mixing derived from a carbon material which is a conductive auxiliary agent, mixing in a composition preparation step such as preparation and mixing, and the like can be mentioned. Carbon materials such as carbon black, graphite, and carbon fiber often contain metallic foreign substances derived from their manufacturing process (as line contamination or catalyst). Although there are differences in the effects of the content of the metallic foreign matter, the effects of the present invention can be enjoyed in any amount.

<Conductive aid>
The conductive auxiliary agent in the present invention is preferably a carbon material. The carbon material is not particularly limited as long as it is a conductive carbon material, but graphite, carbon black, carbon nanotubes, carbon nanofibers, carbon fibers, fullerenes, etc. may be used alone or in combination of two or more. Can be used. The use of carbon black or carbon nanotubes is preferable in terms of conductivity, availability, and cost.

As the carbon black, various commercially available acetylene black, furnace black, hollow carbon black, channel black, thermal black, Ketjen black and the like can be used. The oxidation treatment of carbon black is carried out by treating the carbon black at a high temperature in the air or secondarily treating it with nitrate, nitrogen dioxide, ozone, etc., for example, to form a hydroxy group, a quinone group, a carboxy group, a carbonyl group, etc. This is a treatment for directly introducing (covalently bonding) such an oxygen-containing polar functional group onto the surface of carbon black, and is generally performed in order to improve the dispersibility of carbon black.

As other physical property values representing the physical properties of carbon black, the average primary particle size, BET specific surface area, and pH are known. The BET specific surface area refers to the specific surface area measured by the BET method by nitrogen adsorption (hereinafter, simply referred to as the specific surface area), and this specific surface area corresponds to the surface area of carbon black. The pH changes under the influence of functional groups and impurities on the surface of carbon black.

The average primary particle size of carbon black used in the composition for batteries is preferably 0.01 to 1 μm, which is the same as the average primary particle size range of carbon black used in general dispersions and paints, and is particularly 0.01. ~ 0.2 μm is preferable, and 0.01 to 0.1 μm is more preferable. The average primary particle size referred to here indicates an arithmetic mean particle size measured by an electron microscope, and this physical property value is generally used to represent the physical properties of carbon black. Further, BET specific surface area is preferably a 20~1500m ² / g, more preferably a 30~1000m ² / g, particularly preferably from 30~500m ² / g.

Examples of commercially available carbon black include Talker Black # 4300, # 4400, # 4500, # 5500 (Tokai Carbon Co., Ltd., Furness Black), Graphite L, etc. (Degusa Co., Ltd., Furness Black), Raven7000, 5750, 5250, 5000 ULTRAIII, 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc., PUER BLACK100, 115, 205, etc. (Columbian, Furness Black), # 2350, # 2400B, # 2600B, # 3050B, # 3030B # 3350B, # 3400B, # 5400B, etc. (manufactured by Mitsubishi Chemical Co., Ltd., furnace black), MONARCH1400, 1300, 900, VulcanXC-72R, BlackPearls2000, etc. (manufactured by Cabot, furnace black), Ensaco250G, Ensaco260G, Ensaco350G, Super TIMCAL), Ketjen Black EC-300J, EC-600JD (Lion), Denka Black, Denka Black HS-100, FX-35 (Denka, acetylene black), etc. As graphite, for example, artificial graphite , Phosphorus, and natural graphite such as lump graphite and earth graphite, but the present invention is not limited to these, and two or more types may be used in combination.

<Solvent>
Examples of the solvent include alcohols, glycols, cellosolves, aminoalcohols, amines, ketones, carboxylic acid amides, phosphate amides, sulfoxides, carboxylic acid esters, phosphate esters, and ethers. , Nitrigens, water and the like. Above all, it is preferable to contain N-methyl-2-pyrrolidone (NMP). NMP is used in the manufacture of electrodes for lithium-ion secondary batteries. In the present invention, one or more other solvents may be used in combination as long as the battery performance is not impaired, but it is preferable to use NMP alone from the viewpoint of industrial applicability assumed by the present invention.

<Ammonia>
The ammonia, an inorganic compound represented by the molecular formula NH _3.

When used in the present invention, methods include, but are not limited to, bubbling in a solvent to dissolve ammonia before use, or using a solution in which ammonia is dissolved, such as aqueous ammonia. ..

<Ammonium salt>
Ammonium salt is a salt produced by the combination of ammonia and acid.

Specifically, for example, ammonium carbonate, ammonium hydrogencarbonate, ammonium acetate, ammonium fluoride, ammonium chloride, ammonium bromide, ammonium iodide, ammonium phosphate, ammonium benzoate, ammonium sulfate, ammonium nitrate, ammonium formate, ammonium lactate, Examples thereof include, but are not limited to, ammonium hexachloride platinum (IV) acid.

The ammonium salt used in the present invention can be used alone or in combination of two or more, regardless of whether it is a commercially available product or a synthetic product.

As the ammonium salt, ammonium carbonate, ammonium hydrogencarbonate, ammonium acetate and ammonium chloride are preferable from the viewpoint of availability and safety.

<Amine compounds>
As the amine compound, a primary amine (primary amine), a secondary amine (secondary amine), and a tertiary amine (tertiary amine) are used, and ammonia and a quaternary ammonium compound are not contained. As the amine compound, in addition to monoamine, amine compounds such as diamine, triamine, tetramine, and polyamine having a plurality of amino groups in the molecule can be used. In addition to the above, amino acids, alicyclic nitrogen-containing heterocyclic compounds, and the like can also be used. Therefore, the amino group in the present specification is a primary, secondary or tertiary functional group.

The amine-based compounds used in the present invention include aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, amino acids, alkanol amines, polyoxyalkylene alkyl amines, polyoxyalkylene amines, polyethylene imines, polyamines, and alicyclics. Formula One or more amine-based compounds selected from the group consisting of nitrogen-containing heterocyclic compounds are preferable, and aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, and alkanols having only one amino group are preferable. One or more amine-based compounds selected from the group consisting of amines and polyoxyalkylene alkylamines are more preferable.

The amine compound used in the present invention can be used alone or in combination of two or more, regardless of whether it is a commercially available product or a synthetic product.

Specifically, for example, aliphatic primary amines such as ethylamine, octylamine, laurylamine, myristylamine, stearylamine and oleylamine, aliphatic secondary amines such as diethylamine, dibutylamine and distearylamine, triethylamine and dimethyloctyl. Alidiary tertiary amines such as amines, dimethyldecylamines, dimethyllaurylamines, dimethylmyristylamines, dimethylvalmitylamines, dimethylstearylamines, dimethylbehenylamines, dilaurylmonomethylamines, trioctylamines, alanine, methionine, proline, serine , Amino acids such as asparagine, glutamine, lysine, arginine, histidine, aspartic acid, glutamic acid, cysteine, alkanolamines such as dimethylaminoethanol, monoethanolamine, diethanolamine, methyldiethanolamine, triethanolamine, polyoxyethylene laurylamine, polyoxy Polyoxyalkylene alkyl amines such as ethylene octadecylamine, polyoxyalkylene amines (polyether amines), polyamines such as polyethyleneimine and polyvinylamine, alicyclic nitrogen-containing heterocyclic compounds such as hexamethylenetetramine, morpholin, and piperidine are mentioned. However, it is not limited to these.

The molecular weight of the amine compound is preferably 30 or more and 15,000 or less, more preferably 45 or more and 10000 or less, further preferably 89 or more and 1200 or less, and particularly preferably 89 or more and 500 or less.

The number of carbon atoms of the amine compound is preferably 2 or more and 1000 or less, more preferably 3 or more and 700 or less, further preferably 4 or more and 60 or less, and particularly preferably 4 or more and 24 or less. ..

When the amine compound is an aliphatic amine, those having 2 or more and 40 or less carbon atoms are preferable, those having 8 or more and 36 or less carbon atoms are more preferable, and those having 8 or more and 24 or less carbon atoms are particularly preferable.

The acid dissociation constant (pKa) of the amine compound is preferably 7 or more and 12 or less, more preferably 8 or more and 11 or less, and particularly preferably 9 or more and 10.5 or less. The acid dissociation constant is a value in an aqueous solution at 25 ° C.

From the viewpoint of storage stability, the number of amino groups contained in the amine compound is preferably 1 or more and 4 or less, more preferably 1 or more and 2 or less, and particularly preferably 1.

The chemical structure of the amine compound is an alicyclic nitrogen-containing heterocyclic compound, an amine compound in which an amino group is covalently bonded to α carbon of a carbonyl group or a carboxyl group, and an amine compound having two or more carbonyl groups or carboxyl groups. It is preferably an amine compound other than the compound.

The amine compound is preferably dissolved in 1 part by weight or more with respect to 100 parts by weight of N-methyl-2-pyrrolidone at 0 ° C. or higher and 40 ° C. or lower under atmospheric pressure.

In the polyoxyalkylene alkylamine, the nitrogen atom in the amino group is preferably contained in one molecule in an amount of 1% by weight or more and 15% by weight or less, and more preferably 3% by weight or more and 6% by weight or less. ..

<Inorganic base>
Examples of inorganic bases include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal phosphates, and alkaline earth metal phosphates. And so on.

Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like.

Examples of the hydroxide of the alkaline earth metal include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide and the like.

Examples of the carbonate of the alkali metal include lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and the like.

Examples of carbonates of alkaline earth metals include magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate and the like.

Examples of the alkali metal phosphate include lithium phosphate, trisodium phosphate, disodium hydrogen phosphate, tripotassium phosphate, dipotassium hydrogen phosphate and the like.

Examples of the phosphate of the alkaline earth metal include magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate and the like.

As the inorganic base, sodium hydroxide, lithium hydroxide, sodium carbonate, sodium hydrogencarbonate, and lithium carbonate are preferable.

At least one selected from the group consisting of ammonia, ammonium salts, amine compounds and inorganic bases can be added at the time of dispersion, production of dispersion composition, and preparation of mixture.

The addition amount of at least one selected from the group consisting of ammonia, ammonium salts, amine compounds and inorganic bases is not particularly limited, but can be added to 1 mol of the compounds represented by the general formulas (1) to (8). On the other hand, 0.01 mol or more and 4.0 mol or less are preferable, and 0.1 mol or more and 4 mol or less are more preferable.

Of these compounds, ammonium salts and amine compounds are preferable, and ammonium salts are more preferable.

<Mixed mixture slurry>
When the composition for a battery of the present invention is used as a positive electrode mixture or a negative electrode mixture, at least a positive electrode is used in addition to a carbon material as a conductive additive, compounds represented by the general formulas (1) to (8), and a solvent. Contains active material or negative electrode active material. Further, if necessary, it is preferable to include a binder.

<Electrode active material (positive electrode active material or negative electrode active material)>
The positive electrode active material for a lithium ion secondary battery is not particularly limited, but a metal oxide capable of doping or intercalating lithium ions, a metal compound such as a metal sulfide, a conductive polymer, or the like is used. be able to.
Examples thereof include oxides of transition metals such as Fe, Co, Ni and Mn, composite oxides with lithium, and inorganic compounds such as transition metal sulfides. Specifically, transition metal oxide powders such as MnO, V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , layered lithium nickelate, lithium cobaltate, lithium manganate, lithium manganate having a spinel structure, etc. Examples thereof include a composite oxide powder of lithium and a transition metal, a lithium iron phosphate-based material which is a phosphoric acid compound having an olivine structure, and a transition metal sulfide powder such as TiS ₂ and FeS. Further, a conductive polymer such as polyaniline, polyacetylene, polypyrrole, or polythiophene can also be used. Further, the above-mentioned inorganic compounds and organic compounds may be mixed and used.

The negative electrode active material for the lithium ion secondary battery is not particularly limited as long as it can dope or intercalate lithium ions. For example, metal Li, alloys such as tin alloy, silicon alloy, lead alloy, etc., Li _X Fe ₂ O ₃ , Li _X Fe ₃ O ₄ , Li _X WO ₂ , lithium titanate, lithium vanadium, silicon. Metal oxides such as lithium acid, conductive polymers such as polyacetylene and poly-p-phenylene, amorphous carbonaceous materials such as soft carbon and hard carbon, artificial graphite such as highly graphitized carbon materials, or natural Examples thereof include carbonaceous powders such as graphite, carbon black, mesophase carbon black, resin-fired carbon materials, vapor-grown carbon fibers, and carbon-based materials such as carbon fibers. These negative electrode active materials may be used alone or in combination of two or more.

The electrode active material used in the present invention preferably exhibits basicity in N-methyl-2-pyrrolidone, and more preferably the surface is not coated with a carbon material.

The positive electrode active material used in the present invention is preferably a composite oxide with lithium containing a transition metal such as Al, Fe, Co, Ni, Mn, and lithium containing any one of Al, Co, Ni, and Mn. It is more preferable that it is a composite oxide with Li, and it is particularly preferable that it is a composite oxide with lithium containing Ni and / or Mn. When these active materials are used, particularly good effects can be obtained.

These electrode active material preferably has a BET specific surface area of 0.1 to 10 m ² / g, more preferably a 0.2~5m ² / g, yet those 0.3~3m ² / g preferable.

The average particle size of these electrode active materials is preferably in the range of 0.05 to 100 μm, more preferably in the range of 0.1 to 50 μm. The average particle size of the electrode active material referred to in the present specification is an average value of the particle size measured by an electron microscope.

<Binder>
It is preferable that the mixture slurry of the present invention further contains a binder as a binder. Examples of the binder used include ethylene, propylene, vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, acrylonitrile, styrene, vinyl butyral, vinyl acetal, vinyl pyrrolidone and the like. Polymers or copolymers contained as constituent units; polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, acrylic resin, formaldehyde resin, silicon resin, fluororesin; carboxymethyl cellulose Such cellulose resins; rubbers such as styrene-butadiene rubbers and fluororubbers; conductive resins such as polyaniline and polyacetylene. Further, modified products and mixtures of these resins and copolymers may be used. In particular, from the viewpoint of resistance, it is preferable to use a polymer compound containing a fluorine atom in the molecule, for example, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene or the like.

The weight average molecular weight of these resins as a binder is preferably 10,000 to 1,000,000. If the molecular weight is small, the resistance of the binder may decrease. Although the resistance of the binder is improved as the molecular weight is increased, the viscosity of the binder itself is increased, the workability is lowered, and the binder component acts as a coagulant, and the mixture components may be remarkably agglomerated.

The ratio of the active material to the total solid content in the mixture slurry is preferably 80% by mass or more and 98.5% by mass or less. The ratio of the binder component to the total solid content in the mixture slurry is preferably 1% by mass or more and 10% by mass or less. The appropriate viscosity of the mixture slurry depends on the coating method of the mixture slurry, but is generally preferably 100 mPa · s or more and 30,000 mPa · s or less.

<Manufacturing method of battery composition>
Next, a method for producing the composition of the present invention will be described.
In the composition of the present invention, for example, a carbon material as a conductive auxiliary agent and compounds represented by the general formulas (1) to (8) are mixed with a solvent, and if necessary, a positive electrode active material and a negative electrode active material are mixed. It can be produced by mixing a substance or a binder component. The order of addition of each component is not limited to this. Further, if necessary, a solvent may be further added.

In the above production method, the compounds represented by the general formulas (1) to (8) are completely or partially dissolved or dispersed in a solvent, and a carbon material as a conductive auxiliary agent is added and mixed in the solution. As a result, the compounds represented by the general formulas (1) to (8) and the carbon material are dispersed in the solvent. The concentration of the carbon material in the composition at this time depends on the specific surface area of the carbon material used, the characteristic values peculiar to the carbon material such as the amount of surface functional groups, etc., but is preferably 1% by mass or more and 50% by mass or less. More preferably, it is 5% by mass or more and 35% by mass or less. If the concentration of the carbon material is too low, the production efficiency deteriorates, and if the concentration of the carbon material is too high, the viscosity of the dispersion becomes extremely high, and the mixing / dispersing efficiency may decrease.

The amount of the compounds represented by the general formulas (1) to (8) added is not particularly limited. This is because even if the compound itself remains in the system, it does not significantly affect the battery performance. Of these, 0.001% by mass or more and 30% by mass or less are preferable with respect to 100% by mass of the carbon material as the conductive auxiliary agent. It is preferably 0.005% by mass or more and 25% by mass or less, and more preferably 0.01% by mass or more and 20% by mass or less. If the amount of the compound is small, the effect of suppressing metal ion elution by metal foreign substances cannot be sufficiently obtained. Further, even if it is added excessively, a remarkable effect of improving battery characteristics cannot be obtained.

As an apparatus for dispersing the compound represented by the general formulas (1) to (8) and the carbon material in a solvent, a disperser usually used for pigment dispersion or the like can be used. For example, mixers such as dispersers, homomixers, planetary mixers, homogenizers (M-Technique "Clearmix", PRIMIX "Fillmix", etc.), paint conditioners (Red Devil), ball mills, sand mills ( Simmal Enterprises "Dyno Mill" etc.), Atwriter, Pearl Mill (Eirich "DCP Mill" etc.), Media Disperser such as Coball Mill, Wet Jet Mill (Genus "Genus PY", Sugino Machine Limited Medialess dispersers such as "Starburst" manufactured by "Starburst" manufactured by "Starburst" manufactured by Nanomizer, "Claire SS-5" manufactured by M-Technique, "MICROS" manufactured by Nara Machinery, and other roll mills. It is not limited to.
As media type dispersers, paint conditioners (manufactured by Red Devil), colloid mills ("PUC colloid mill" manufactured by PUC, "colloid mill MK" manufactured by IKA), cone mills ("corn mill MKO" manufactured by IKA), etc. Etc.), ball mills, sand mills (such as "Dyno mill" manufactured by Simmal Enterprises), attritors, pearl mills (such as "DCP mill" manufactured by Eirich), colloid mills, etc., but are not limited thereto. .. As the disperser, only one type may be used, or a plurality of types of devices may be used in combination.

As a method for adding the positive electrode active material or the negative electrode active material, the positive electrode is formed by dispersing a carbon material as a conductive auxiliary agent together with compounds represented by the general formulas (1) to (8) in a solvent while stirring the composition. Examples thereof include a method of adding and dispersing an active material or a negative electrode active material. Further, when the carbon material as the conductive auxiliary agent is dispersed in the solvent together with the compound, a part or all of the positive electrode active material or the negative electrode active material may be added at the same time to perform the dispersion treatment. Further, as an apparatus for performing mixing and dispersion at this time, the above-mentioned disperser used for ordinary pigment dispersion or the like can be used.

As a method of adding the binder component, the solid binder component is added while stirring the composition in which the carbon material as the conductive auxiliary agent is dispersed in the solvent together with the compounds represented by the general formulas (1) to (8). And there is a method of dissolving. Another example is a method in which a binder component dissolved in a solvent is prepared in advance and mixed with the above composition. Further, after adding the binder component to the composition, the dispersion treatment may be performed again with the dispersion device. Further, when the carbon material as the conductive auxiliary agent is dispersed in the solvent together with the compound, a part or all of the binder component can be added at the same time to carry out the dispersion treatment.

<Electrode>
An electrode can be obtained by, for example, coating and drying the mixture slurry of the present invention on an electrode base material to form a carbon black mixture film for a battery.

(Electrode base material, current collector)
The material and shape of the electrode base material used for the electrode are not particularly limited, and those suitable for various secondary batteries can be appropriately selected. For example, a current collector can be mentioned. Examples of the material of the current collector include metals and alloys such as aluminum, copper, nickel, titanium, platinum, and stainless steel. As the shape, a foil on a flat plate is generally used, but a foil with a roughened surface, a foil with holes, and a mesh-shaped current collector can also be used. Further, the current collector may be provided with a base layer using a conductive base layer forming composition.

The method of applying the mixture slurry or the composition for forming the base layer on the current collector is not particularly limited, and a known method can be used. Specifically, a die coating method, a dip coating method, a roll coating method, a doctor coating method, a knife coating method, a spray coating method, a gravure coating method, a screen printing method, an electrostatic coating method, etc. can be mentioned, and a drying method can be mentioned. Examples thereof include a stand-alone dryer, a blower dryer, a warm air dryer, an infrared heater, a far infrared heater, and the like, but the present invention is not particularly limited thereto.

Further, after coating, a rolling process such as a lithographic press or a calendar roll may be performed. The thickness of the electrode mixture layer is generally 1 μm or more and 500 μm or less, preferably 10 μm or more and 300 μm or less.

<Secondary battery>
A lithium ion secondary battery can be obtained by using the above electrodes for at least one of the positive electrode and the negative electrode. At this time, in the lithium secondary battery, a conventionally known electrolytic solution, separator, or the like can be appropriately used. Further, it may be used for an electric double layer capacitor, a lithium ion capacitor, or a hybrid capacitor thereof.

<Electrolytic solution>
As the electrolytic solution, an electrolyte containing lithium is dissolved in a non-aqueous solvent. Electrolytes include LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₃ C. , LiI, LiBr, LiCl, LiAlCl, LiHF ₂ , LiSCN, LiBPh ₄ (where Ph represents a phenyl group) and the like, but are not limited thereto.

The non-aqueous solvent is not particularly limited, and is, for example, carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate; γ-butyrolactone, γ-valerolactone, and γ-. Lactones such as octanoic lactones; tetrahydrofuran, 2-methyltetraethane, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,2-methoxyethane, 1,2-ethoxyethane, and 1,2. -Glymees such as dibutoxyethane; esters such as methylformates, methylacetates, and methylpropionates; sulfoxides such as dimethyl sulfoxide and sulfolane; and nitriles such as acetonitrile. Each of these solvents may be used alone, or two or more kinds may be mixed and used.

(separator)
Examples of the separator include polyethylene non-woven fabric, polypropylene non-woven fabric, polyamide non-woven fabric, and those obtained by subjecting them to a hydrophilic treatment, but the separator is not particularly limited thereto.

(Battery structure / configuration)
The structure of the lithium ion secondary battery using the composition of the present invention is not particularly limited, but is usually composed of a positive electrode and a negative electrode, and a separator provided as needed, and is composed of a paper type, a cylindrical type, a button type, and the like. It can have various shapes such as a laminated type according to the purpose of use.

Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. In this embodiment, parts represent parts by mass and% represents% by mass. The compounds, carbon materials, electrode active materials, etc. used in Examples and Comparative Examples are shown below.

Further, although the specification describes an example in which only the carbon material contains a copper foreign substance as the raw material, the raw material for mixing the copper foreign substance into the battery composition is not limited to the carbon material. Further, not only the copper foreign matter contained in the raw material, but also copper and copper oxide mixed in the manufacturing process of the battery composition are the objects of the present invention. Although detailed results are not described, the same effect was confirmed with nickel and tin, which are metals other than copper.

<Compounds represented by general formulas (1) to (8)>
The structures of the compounds used in Examples and Comparative Examples are shown in Table 2.
However, examples in which compounds other than compounds A, B, C, F, G, H, and I are used in the present specification are reference examples.

The above compounds were purchased from the following companies.
Compound A (C): Tokyo Chemical Industry Co., Ltd.
Compound B: Tokyo Chemical Industry Co., Ltd.
Compound D: Sigma-Aldrich Japan Co., Ltd.
Compound E: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound F: Tokyo Chemical Industry Co., Ltd.
Compound G: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound H: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound I: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound J: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound K: Tokyo Chemical Industry Co., Ltd.
Compound L: Tokyo Chemical Industry Co., Ltd.
Compound M: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound N: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound O: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound P: Fujifilm Wako Pure Chemical Industries, Ltd.
Compound AA: Tokyo Chemical Industry Co., Ltd.
Compound AB: Sigma-Aldrich Japan Co., Ltd.
Compound AC: Sigma-Aldrich Japan Co., Ltd.

<Amine compounds>
-N-Butylamine: Aliphatic primary amine. C ₄ H ₉ NH ₂
-N-octylamine: Aliphatic primary amine. Molecular formula C ⁸ H ₁₇ NH ₂ . Molecular weight 129. Hereinafter, it is abbreviated as octylamine.
-Stearylamine: Aliphatic primary amine. Molecular formula C1 ₈ H ₃₇ NH ₂ . Molecular weight 269.5.
-Diethylamine: Aliphatic secondary amine. Molecular formula C ₄ H ₁₁ N. Molecular weight 73.
-Distearylamine: Aliphatic secondary amine. Molecular formula C ₃₆ H ₇₅ N.
-Triethylamine: Aliphatic tertiary amine. Molecular formula C ₆ H ₁₅ N. Molecular weight 101.
-Tri-n-octylamine: Aliphatic tertiary amine. Molecular formula C ₂₄ H ₅₁ N. Molecular weight 354. Hereinafter, it is abbreviated as trioctylamine.
-Ethanolamine: Alkanolamine-based primary amine. Molecular formula C ₂ H ₇ NO, molecular weight 61.
-Triethanolamine: Alkanolamine-based tertiary amine. Molecular formula C ₆ H ₁₅ NO 3. pKa = 7.6.
-Amit 102 (manufactured by Kao Corporation): Polyoxyethylene dodecylamine (average EO = 2 mol added, tertiary amine).
-Amit 105 (manufactured by Kao Corporation): Polyoxyethylene dodecylamine (average EO = 5 mol addition, tertiary amine).
-Amit 302 (manufactured by Kao Corporation): Polyoxyethylene octadecylamine (average EO = 2 mol added, tertiary amine).
-Amit 320 (manufactured by Kao Corporation): Polyoxyethylene octadecylamine (average EO = 20 mol added, tertiary amine).
-Polyethyleneimine 1200 (manufactured by Junsei Chemical Co., Ltd.): Molecular weight 1200, amine value 19. Hereinafter, it is abbreviated as PEI1200.
-Polyethyleneimine 1800 (manufactured by Junsei Chemical Co., Ltd.): Molecular weight 1800, amine value 19. Hereinafter, it is abbreviated as PEI1800.
-Polyethyleneimine 10000 (manufactured by Junsei Chemical Co., Ltd.): Molecular weight 10000, amine value 18. Hereinafter, it is abbreviated as PEI 10000.
-Hexamethylenetetramine: an alicyclic nitrogen-containing heterocyclic compound (tertiary amine). Molecular formula C ₆ H ₁₂ N ₄ .
-L-aspartic acid: an acidic amino acid. Molecular formula C ₄ H ₇ NO ₂ . Hereinafter, it is abbreviated as aspartic acid.
-L-asparagine monohydrate: Neutral amino acid. Molecular formula C ₄ H ₈ N ₂ O ₃ . Hereinafter, it is abbreviated as asparagine.

<Carbon material>
-Denka Black HS-100 (manufactured by Denka Co., Ltd.): 39 m ² / g obtained by the S-BET method from acetylene black and the amount of nitrogen adsorbed, hereinafter abbreviated as "HS100".
-LITX (registered trademark) HP (manufactured by CABOT): Furnace black, specific surface area of 100 m ² / g determined by the S-BET method from the amount of nitrogen adsorbed, hereinafter abbreviated as "LITX HP".
-EC-300J (manufactured by Lion Specialty Chemicals Co., Ltd.): Ketchen Black, specific surface area of 800 m ² / g calculated by the S-BET method from the amount of nitrogen adsorbed, hereinafter abbreviated as "EC300J".
-Carbon nanotubes: Multi-walled carbon nanotubes (Flotube 7010 manufactured by Canon), fiber diameter 7 to 11 μm, hereinafter abbreviated as “FT7010”.

<Others>
-Copper powder: Fujifilm Wako Pure Chemical Industries, Ltd., 75 μm, purity 99.9%
-Copper oxide: Kishida Chemical Co., Ltd., 150 μm (100 mesh)

<Binder>
-KF polymer W7300 (manufactured by Kureha Corporation): polyvinylidene fluoride (PVDF), weight average molecular weight of about 1 million. Hereinafter, it is abbreviated as PVDF.

<Electrode active material>
-LiNi _1/3 Mn _1/3 Co _1/3 O ₂ : Positive electrode active material, lithium manganese manganese cobalt oxide. The average primary particle size determined by observing with an electron microscope is 5.5 μm, and the specific surface area determined by the S-BET method from the amount of nitrogen adsorbed is 0.62 m ² / g. Hereinafter, it is abbreviated as “NCM”.
-Artificial graphite: Negative electrode active material, average particle size 12 μm, hereinafter abbreviated as “graphite”.

<Evaluation of battery composition>
HS flat cells (manufactured by Hohsen) are used for the effect of suppressing elution into the battery composition when copper foreign matter is mixed by adding the compounds represented by the general formulas (1) to (8) to the battery composition. It was evaluated by the linear sweep voltammetry measurement (hereinafter referred to as LSV measurement). The evaluation of the battery composition was carried out by (1) LSV measurement of the battery composition to which a copper foreign substance was added, and (2) LSV measurement using the filtration residue of the battery composition. The evaluation of (1) confirmed the effect of the compound on a certain amount of copper foreign matter, and the evaluation of (2) confirmed whether the compound actually had an effect on the copper foreign matter derived from the carbon material. ..

LSV measurement is a method of sweeping the potential of an electrode in a specific range, measuring the reaction current flowing accordingly, and analyzing each electrochemical information. In this measurement, the reaction amount is tilted from the current amount. The reaction rate can be confirmed quantitatively. When copper is present in the positive electrode, the oxidation-reduction potential of copper with respect to the negative electrode lithium foil is about 3.4 V when considered from the standard electrode potential, which is the electron transfer associated with the copper elution reaction at a voltage of about 3.4 V or higher. Means that happens. The rise of the reaction current in the LSV measurement represents the reaction start potential, and the amount and slope of the reaction current represent the ease of elution of copper. When the compound acts on the copper foreign matter and can suppress the elution of copper ions, the oxidation-reduction potential of copper becomes high, so that the reaction start potential in the LSV measurement shifts to the high voltage side.

(Preparation of battery composition)
<Measurement method of metal ion / atom content in raw materials>
The carbon material used in the examples was pretreated by the acid decomposition method according to the Japanese Industrial Standard JIS K 0116; 2014, and the content of copper ions and atoms was measured by the ICP luminescence analysis method. By using these carbon materials as raw materials, foreign copper substances are mixed in the composition.
HS100: 100ppb
・ LITXHP: 100ppb
-EC300J: 140ppb
FT7010: 120ppb

[Example 1]
Add 79.8 parts of NMP to a glass bottle, add 20 parts of HS10020 parts, 0.2 parts of compound A (C) and ammonium carbonate, and add copper powder so that the copper powder is 250 ppm based on the total amount of the battery composition. The battery composition D-1 was obtained by thoroughly mixing and stirring with.

[Examples 2 to 53, Comparative Examples 1 to 4]
According to the composition shown in Table 2, a battery composition was prepared in the same manner as in Example 1 to obtain battery compositions D-2 to 58.

[Example 54]
90 parts of NMP was charged in a glass bottle, 10 parts of HS100, 0.05 part of compound A (C) and 0.3 part of ammonium carbonate were added, and the mixture was sufficiently mixed and stirred with a disper to obtain a battery composition D-59.

[Examples 55 to 63, Comparative Examples 5 to 8]
According to the composition shown in Table 4, a battery composition was prepared in the same manner as in Example 34 to obtain battery compositions D-59 to 72.

<(1) LSV measurement of battery composition to which copper foreign matter is added>
The battery compositions obtained in Examples 1 to 53 and Comparative Examples 1 to 4 were subjected to LSV measurement according to the following procedure.
(1) A conductive paste is prepared by adding a conductive auxiliary agent, PVDF as a binder, and NMP as an organic solvent to the prepared battery composition and mixing and stirring.
(2) The conductive paste prepared in (1) is applied onto the surface of the aluminum foil and dried until the NMP is completely removed. The solid content of the aluminum foil per unit area is 2 mg / cm ² , and the conductivity is conductive. Auxiliary agent: PVDF = 8: 2 evaluation test working electrode is prepared.
(3) A two-pole sealed metal in which a lithium foil is used as a counter electrode, and the lithium foil is laminated with the working electrode produced in (2) via a separator, and the electrode body is housed together with a non-aqueous electrolytic solution. Build a cell.
(4) LSV measurement is performed under the following conditions using the constructed test battery.
・ Sweep start potential; 3.0V (vsLi / Li ⁺ )
-Sweep end potential; 4.3V (vsLi / Li ⁺ )
Sweeping speed: 10 mV / min.
-Measurement temperature: 25 ° C
(5) The redox start potential of copper, which is an index of the ease of elution of copper, was set to the potential at the time when the current density reached ²⁰ μA / cm ² from the start of the potential sweep. The redox initiation potential of copper in this measurement indicates that the higher the potential, the more delayed the elution of copper. It was also confirmed whether or not a short circuit occurred during the sweep. Those that could be measured without a short circuit were marked with ◯, and those that were short-circuited in the middle were marked with x.

<(2) LSV measurement using the filtration residue of the battery composition>
The battery compositions obtained in Examples 54 to 63 and Comparative Examples 5 to 8 were subjected to LSV measurement using the filtration residue according to the following procedure.
(1) The prepared battery composition is filtered through a 25 μm mesh to recover a residue containing a copper foreign substance derived from a carbon material, which is reslurried with NMP and dried under reduced pressure at 40 ° C.
(2) A conductive paste is prepared by adding the residue of (1), a conductive auxiliary agent, PVDF as a binder, and NMP as an organic solvent, and mixing and stirring.
(3) The conductive paste prepared in (2) is applied onto the surface of the aluminum foil, dried until the NMP is completely removed, and the solid content per unit area of the aluminum foil is 2 mg / cm ² , which is conductive. An agent: PVDF = 8: 2, and a working electrode for evaluation test containing the residue in an amount of 5% of a conductive additive is prepared.
(4) A two-pole sealed metal in which a lithium foil is used as a counter electrode, and the lithium foil is laminated with the working electrode produced in (3) via a separator, and the electrode body is housed together with a non-aqueous electrolytic solution. Build a cell.
(5) LSV measurement is performed under the following conditions using the constructed test battery.
・ Sweep start potential; 3.0V (vsLi / Li ⁺ )
-Sweep end potential; 4.3V (vsLi / Li ⁺ )
Sweeping speed: 10 mV / min.
-Measurement temperature: 25 ° C
(6) The redox start potential of copper, which is an index of the ease of elution of copper, was set to the potential at the time when the current density reached ²⁰ μA / cm ² from the start of the potential sweep. The redox initiation potential of copper in this measurement indicates that the higher the potential, the more delayed the elution of copper. It was also confirmed whether or not a short circuit occurred during the sweep. Those that could be measured without a short circuit were marked with ◯, and those that were short-circuited in the middle were marked with x.

A more specific evaluation method will be shown by taking Examples 1 and 54 as examples.
(1) LSV measurement evaluation of the battery composition obtained in Example 1. First, HS100 was used as the conductive auxiliary agent and PVDF was used as the binder in the prepared battery composition D-1, and the conductive auxiliary agent: binder was used. Weighed so that the ratio was 8: 2, all of these were added to the solvent NMP, mixed and stirred to prepare a conductive paste. The prepared conductive paste was applied to an aluminum foil having a thickness of 20 μm using a doctor blade, and then heated and dried at 120 ° C. under reduced pressure, and this was used as a punching electrode with a radius of 9 mm. A metal lithium foil (thickness 0.15 mm) is used as a counter electrode, and a separator made of a porous polypropylene film (thickness 20 μm, porosity 50% by volume) is inserted and laminated between the working electrode and the counter electrode, and a non-aqueous electrolytic solution (non-aqueous electrolytic solution (thickness: 50% by volume)) is inserted and laminated. A bipolar sealed metal cell (HS flat cell manufactured by Hosen Co., Ltd.) is filled with a mixed solvent in which ethylene carbonate and diethyl carbonate are mixed at a volume ratio of 1: 1 and LiPF ₆ is dissolved at a concentration of 1 M. Assembled. The cells were assembled in a glove box replaced with argon gas.
(2) LSV measurement using the filtration residue of the battery composition obtained in Example 54 First, the prepared battery composition D-56 was filtered with a 25 μm mesh, and the residue containing copper foreign matter was recovered and used. The mixture was washed with NMP and dried under reduced pressure at 40 ° C. to obtain 0.05 g of a residual solid. HS-100 was used as the conductive auxiliary agent and PVDF was used as the binder, and the weight was weighed so that the conductive auxiliary agent: binder was 8: 2, and a residual solid of 1% of the conductive auxiliary agent was further added thereto. A conductive paste was prepared by dispersing in a solvent NMP. The prepared conductive paste was applied to an aluminum foil having a thickness of 20 μm using a doctor blade, and then heated and dried at 120 ° C. under reduced pressure, and this was used as a punching electrode with a radius of 9 mm. A metal lithium foil (thickness 0.15 mm) is used as a counter electrode, and a separator made of a porous polypropylene film (thickness 20 μm, porosity 50% by volume) is inserted and laminated between the working electrode and the counter electrode, and a non-aqueous electrolytic solution (non-aqueous electrolytic solution (thickness: 50% by volume)) is inserted and laminated. A bipolar sealed metal cell (HS flat cell manufactured by Hosen Co., Ltd.) is filled with a mixed solvent in which ethylene carbonate and diethyl carbonate are mixed at a volume ratio of 1: 1 and LiPF ₆ is dissolved at a concentration of 1 M. Assembled. The cells were assembled in a glove box replaced with argon gas.

The battery compositions D-1 to 53 obtained in Examples 1 to 53 had good LSV evaluation results even when a copper foreign substance was added. Based on the LSV evaluation results of Comparative Example 1 and the addition of the compounds represented by the general formulas (1) to (8), the potential reaction of copper is increased, and the deterioration of battery performance such as short circuit is improved in the LSV evaluation. It was shown to be done. From the results of Comparative Examples 2 to 4, even if the compounds have a similar structure, if they do not have the structure characterized by the present invention, a sufficient effect on copper foreign matter is not exhibited, and the battery performance deteriorates in the LSV evaluation. It was confirmed that (battery short circuit) occurred.

The same effect was confirmed in the LSV measurement using the filtration residue of the battery compositions D-59 to 68 obtained in Examples 54 to 63. Since a short circuit was confirmed in the LSV evaluation of Comparative Example 5, the compound could sufficiently act on the copper foreign matter even when only a trace amount of copper foreign matter was present (even if only the copper foreign matter derived from the carbon material was used). Shown. That is, from this evaluation, it was confirmed that the compound actually shows an effect on the copper foreign matter derived from the carbon material.

<Preparation of mixture slurry>
In this example and the comparative example, in order to evaluate the battery resistance when copper foreign matter is mixed, copper foreign matter is added at the time of preparing the battery composition (added so that the amount of copper foreign matter becomes uniform), and they are mixed. Used for slurry preparation. The composition of the battery composition used is as shown in Table 2 above.

<Positive electrode mixture slurry>
[Example 64]
20 parts of a binder solution (that is, PVDF2) in which PVDF was previously dissolved in NMP so as to have a solid content of 10% with respect to the previously prepared battery composition D-1 (so that the amount of carbon black was 8 parts). Part), 90 parts of LiNi _1/3 Mn _1/3 Co _1/3 O ₂ (NCM) was charged as a positive electrode active material and mixed sufficiently with a homomixer to obtain a positive electrode mixture slurry BC-1.

[Examples 65-116, Comparative Examples 9-12]
According to the composition shown in Table 5, positive electrode mixture slurries BC-2 to 53 and 61 to 64 were obtained in the same manner as in Example 64.

<Negative electrode mixture slurry>
[Example 117]
20 parts of a binder solution (that is, PVDF2) in which PVDF was previously dissolved in NMP so as to have a solid content of 10% with respect to the previously prepared battery composition D-1 (so that the amount of carbon black was 8 parts). Part), 90 parts of graphite was charged as the negative electrode active material and mixed sufficiently with a homomixer to obtain a negative electrode mixture slurry BC-54.

[Examples 118 to 123, Comparative Examples 13 to 16]
Negative electrode mixture slurries BC-54-60 and 65-68 were obtained in the same manner as in Example 117 according to the composition shown in Table 5.

<Manufacturing electrodes for secondary batteries>
Electrodes were prepared using the mixture slurries obtained in each of the above Examples and Comparative Examples.
The positive electrode mixture slurry is applied onto an aluminum foil having a thickness of 20 μm, and the negative electrode mixture slurry is applied onto a copper foil having a thickness of 20 μm using a doctor blade, and then dried under reduced pressure at 120 ° C. for 30 minutes. An electrode having a thickness of 100 μm was prepared.

<Assembly of cell for evaluation of lithium ion secondary battery>
A separator made of a porous polypropylene film (thickness 20 μm, empty) between the working electrode and the counter electrode, with the positive electrode and negative electrode prepared earlier as the working electrode with a radius of 9 mm and the metal lithium foil (thickness 0.15 mm) as the counter electrode. (Pore ratio 50%) is inserted and laminated, and an electrolytic solution (a non-aqueous electrolytic solution in which LiPF ₆ is dissolved at a concentration of 1 M in a mixed solvent in which ethylene carbonate and diethyl carbonate are mixed at a volume ratio of 1: 1) is filled with two electrodes. A closed metal cell (HS flat cell manufactured by Hosensha) was assembled. The cells were assembled in a glove box replaced with argon gas.

<Evaluation of cell for evaluation of positive electrode of lithium ion secondary battery>
[Examples 64 to 116] [Comparative Examples 9 to 12]
The prepared positive electrode evaluation cell is fully charged at 30 ° C. using a charging / discharging device (SM-8 manufactured by Hokuto Denko Co., Ltd.) with a constant current constant voltage charge (upper limit voltage 4.2 V) with a charging rate of 1.0 C. , Charging / discharging to discharge to the lower limit voltage of 3.0V at a constant current at the same rate as during charging was set as one cycle (charging / discharging interval pause time 30 minutes), and this cycle was performed for a total of 20 cycles to perform charging / discharging. .. The evaluated cell was disassembled in the glove box replaced with argon gas, and it was confirmed whether or not the cell was short-circuited within 20 cycles. The evaluation results are shown in Table 6 .

<Evaluation of cell for evaluation of negative electrode of lithium ion secondary battery>
[Examples 117 to 123] [Comparative Examples 13 to 16]
The prepared positive electrode evaluation cell is fully charged at 30 ° C. using a charging / discharging device (SM-8 manufactured by Hokuto Denko Co., Ltd.) with a constant current constant voltage charging (lower limit voltage 0.0V) with a charging rate of 1.0C. One cycle (charge / discharge interval pause time 30 minutes) was set to charge / discharge to discharge to the lower limit voltage of 2.0V at a constant current at the same rate as during charging, and this cycle was performed for a total of 20 cycles to perform charging / discharging. .. The evaluated cell was disassembled in the glove box replaced with argon gas, and it was confirmed whether or not the cell was short-circuited within 20 cycles. The evaluation results are shown in Table 6 .

Battery abnormality was evaluated in the following two stages.
×; Short circuit during cycle 〇; The charge / discharge capacity retention rate for 20 cycles or more is the percentage of the discharge capacity in the 20th cycle to the discharge capacity in the 1st cycle, and the closer the value is to 100%, the better. Shown.
◎ (Extremely good); When the capacity retention rate is 95% or more ○ (Good); When the capacity retention rate is 90% or more and less than 95% △ (Normal); When the capacity retention rate is 80% or more and less than 90% Numerical value None (-); When a normal charge / discharge curve cannot be obtained due to peeling of the coating film from the current collector, short circuit, etc., and the capacity cannot be obtained.

From Table 6 , Examples 64 to 123 using the electrodes prepared with the mixture slurry of the present invention can be charged and discharged without a short circuit even after 20 cycles even though copper foreign matter is mixed in the positive electrode or the negative electrode. The capacity retention rate was also good.
On the other hand, in all of Comparative Examples 9 to 16, metal foreign matter was oxidized at the positive electrode and reduced at the negative electrode, causing a voltage failure and short-circuiting. From these evaluation results, it was shown that by adding the compounds represented by the general formulas (1) to (8) to the battery composition, the battery abnormality due to the mixed copper foreign matter can be suppressed.

Claims (6)

At least one selected from the group consisting of compounds represented by the following general formulas (1) , (3) and (4) , conductive aids and / or solvents , ammonia, ammonium salts, amine compounds and inorganic bases. A composition for an electrode of a lithium ion secondary battery , which comprises.
General formula (1)



One general formula (3)



General formula (4)


[In general formulas (1) , (3), (4),
X _{1 and} X ₂ may independently have an alkoxy group, a halogen atom, and a substituent.
It represents a reel group, a hydroxyl group or -OCOR, where R represents an alkyl group which may have a substituent or an aryl group which may have a substituent.
Y ₇ is hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom.
Y ₃ to Y ₆ are each independently hydrogen, an optionally substituted alkyl group, an aryl group or a halogen atom which may have a substituent, at least one is hydrogen.
R ₁ and R ₂ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, a hydroxyl group, a nitro group or an amino group, respectively. ] The electrode composition for a lithium ion secondary battery according to claim 1 , further comprising a binder component. The electrode composition for a lithium ion secondary battery according to claim 1 or 2 , further comprising a positive electrode active material or a negative electrode active material. Compounds represented by the general formulas (1), (3), and (4), at least one selected from the group consisting of ammonia, ammonium salts, amine compounds, and inorganic bases, and positive electrode active materials or negative electrode active materials. A mixture film for electrodes of a lithium ion secondary battery, which comprises.

General formula (1)



General formula (3)



General formula (4)


[In general formulas (1), (3), (4),
X _{1 and} X ₂ may independently have an alkoxy group, a halogen atom, and a substituent.
It represents a reel group, a hydroxyl group or -OCOR, where R represents an alkyl group which may have a substituent or an aryl group which may have a substituent.
Y ₇ is hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom.
Y ₃ to Y ₆ are each independently hydrogen, an optionally substituted alkyl group, an aryl group or a halogen atom which may have a substituent, at least one is hydrogen.
R ₁ and R ₂ are independently hydrogen, an alkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, a hydroxyl group, a nitro group or an amino group, respectively. ]

A battery electrode comprising the mixture film for the electrode of the lithium ion secondary battery according to claim 4 on the electrode base material. A lithium ion secondary battery provided with the battery electrode according to claim 5 .