JP2010086955A - Composite material for battery electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve performance of a battery produced in such a way that in an active material for a battery electrode, by covering the surface of the active material for the battery electrode using a carbon material dispersed without inhibiting conductibility, reduction of a conductive auxiliary agent is achieved with contact conservation between the active material in the electrode and the conductive auxiliary agent, and between the conductive auxiliary agents. <P>SOLUTION: A dispersion element in which one or more derivatives selected from the group consisting of an organic dye derivative having an acidic function, a triazine derivative having an acidic function, an organic dye derivative having a basic function and a triazine derivative having a basic function are dispersed in a dispersant conductive carbon material, and an active material particle are mixed, and then a solvent is removed by drying the mixtures, so that a composite material in which the surface of the active material for the battery electrode is covered with the carbon material is produced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a composite material in which the surface of a battery electrode active material is coated with a carbon material dispersed without inhibiting conductivity. In particular, the active material composite material of the present invention is suitably used for producing a lithium ion secondary battery. The present invention also relates to a lithium ion secondary battery that suppresses a decrease in battery capacity during charge / discharge cycle operation and has an improved capacity.

  In recent years, small portable electronic devices such as digital cameras and mobile phones have been widely used. These electronic devices have always been required to minimize the volume and reduce the weight, and the batteries to be mounted are also required to be small, light, and have a large capacity. Also, in large-sized secondary batteries for automobiles and the like, it is desired to realize a large non-aqueous electrolyte secondary battery instead of a conventional lead-acid battery.

  In order to meet such demands, lithium ion secondary batteries are being actively developed. As an electrode of a lithium ion secondary battery, a positive electrode in which an electrode mixture composed of a positive electrode active material containing lithium ions, a conductive additive, an organic binder, and the like is fixed to the surface of a metal foil current collector, and a lithium ion A negative electrode is used in which an electrode mixture made of a removable negative electrode active material, a conductive additive, an organic binder, and the like is fixed to the surface of a current collector of a metal foil.

  When the battery is charged, electrons and lithium ions are transferred from the positive electrode active material to the negative electrode active material through an electrolyte solution in which a lithium electrolyte is dissolved in a non-aqueous organic solvent, and are captured. Charging proceeds by the action. On the other hand, during discharge, lithium ions are occluded in the positive electrode active material. At that time, discharge proceeds by the action of lithium ions diffusing to the positive electrode side and electrons conducted from the positive electrode current collector. For this reason, it is very important to select a conductive material with high conductivity and a fine composite structure of an active material and a conductive material as factors affecting battery characteristics, particularly high-speed discharge performance (high output). Become.

  The active material is not particularly limited, but in the case of a positive electrode of a lithium ion secondary battery, a metal oxide that can be doped or intercalated with lithium ions, a metal compound such as a metal sulfide, and a conductive polymer are used. can do. Examples thereof include lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, and lithium phosphorus oxide having an olivine structure.

  For negative electrodes of lithium ion secondary batteries, vapor-grown carbon fibers, mesophase pitch carbon fibers, carbonaceous materials such as spherical carbon, lithium titanate, tungsten oxide, amorphous tin oxide, tin silicon oxide, silicon oxide, etc. And metal oxides.

  Among these electrode active materials, positive and negative electrode active materials such as oxides, excluding carbonaceous active materials, have low electronic conductivity by themselves, and sufficient battery performance cannot be obtained when used alone. The active material is mixed with a conductive material such as a carbon material (for example, acetylene black) or graphite (graphite) and a binder, which is a binder, into a paste (electrode mixture paste). An attempt has been made to secure the conductivity and reduce the internal resistance of the electrode by forming an active material layer on the surface of the metal foil by coating and drying on the surface of the metal foil.

  On the other hand, although the carbonaceous negative electrode active material such as graphite itself has conductivity, it is known that charging and discharging characteristics are improved by adding carbon black as a conductive additive together with graphite. This is because the graphite particles generally used are large, so if graphite alone is used, the gap when filled in the electrode layer will increase. However, when carbon black is used as a conductive additive, fine carbon black is used. It seems that the contact area increases by filling the gaps between the graphite particles and the resistance decreases.

  By the way, reducing the internal resistance of the electrode is one of the very important factors for enabling discharge with a large current and improving the efficiency of charge and discharge. However, carbon materials such as carbon black, which are generally used as conductive aids, have a large structure and specific surface area, and thus have a strong cohesive force and are uniformly mixed and dispersed in the paste for forming an electrode mixture of a lithium ion secondary battery. Is difficult. If the control of the dispersibility and particle size of the carbon particles as the conductive auxiliary agent is insufficient, the internal resistance of the electrode cannot be reduced because a uniform conductive network is not formed. As a result, lithium as the active material There has been a problem that the performance of transition metal composite oxides and graphite cannot be sufficiently extracted. In addition, if the dispersion of the conductive additive in the electrode mixture is insufficient, resistance distribution occurs on the electrode plate due to partial aggregation, current concentrates when used as a battery, and partial heat generation occurs. In addition, problems such as accelerated deterioration may occur.

  For this reason, in the conventional method for preparing an electrode mixture paste, in order to obtain sufficient electrode conductivity, it is necessary to add a large amount of a conductive additive to the electrode mixture. As a result, there has been a problem that the charge / discharge capacity per electrode volume or electrode weight decreases.

  In addition, as the lithium ion secondary battery is used repeatedly, the capacity decreases and the deterioration occurs. One of the causes of the deterioration of the battery may be that the contact between the active material in the electrode and the conductive auxiliary agent is deteriorated, and electricity cannot be taken out to the outside. From this point of view, it is desirable to maintain good contact between the active material in the electrode and the conductive assistant while reducing the conductive assistant as much as possible.

  In general, the active material particles used are composed of micron-order, primary particles of sub-micron order or less, or secondary particles obtained by agglomerating or consolidating a plurality of these primary particles. In many cases, secondary particles are formed. For example, lithium transition metal composite oxides, which are positive electrode active materials, are usually prepared by a solid phase synthesis method in which a transition metal oxide is melted and lithiated with lithium carbonate, or lithium hydroxide is dropped into an aqueous solution of a transition metal salt. Although it is produced by a solution synthesis method in which it is neutralized and lithiated, in any case, secondary particles are inevitable. The electrical conductivity of the secondary particles is lower than that of the primary particles due to the presence of the particle interface. In addition, when a conductive additive is added to the electrode mixture paste, there are particles that are not in direct contact with the primary particles in the conductive auxiliary particles because the active material is secondary particles. The effect of adding a conductive additive cannot be fully exhibited. Therefore, in the preparation of the composite paste, the paste is mixed for a long time using a special mixer so that the conductive auxiliary agent is in sufficient contact with the active material particles.

  Further, the prepared slurry must be stably maintained in a uniform composition without separation even when applied to a current collector or after drying. In addition, properties suitable for application must be stably maintained for a long time. However, since the specific gravity of the active material particles and the conductive aid particles are greatly different, they are easily separated from each other in the paste, and it is very difficult to obtain such a stable paste. For this reason, advanced knowledge and experience are required for the selection of the conductive assistant and the binder, or the determination of the blending amount.

  For these reasons, several attempts have been made to improve the fine composite structure relating to the positive electrode of the lithium ion secondary battery. For example, Patent Document 1 proposes a positive electrode material in which a positive electrode active material surface is coated with a carbon material by a method of mixing a positive electrode active material and ketjen black as a carbon material and applying a compressive shear stress in a dry manner. .

  However, in this method, it is difficult to control the coverage, and the carbon material is likely to be densely coated on the surface of the positive electrode active material, so that the lithium ion path is blocked, and as a result, high-speed discharge performance is difficult to improve. . In addition, although the conductivity of the positive electrode active material is improved by the coating, the carbon material is attached only to the outer peripheral portion of the active material secondary particles, so the conductivity between the primary particles inside the secondary particles is the conductivity of the active material itself. Because it depends on the rate, it is not enough. Further, due to expansion / contraction of the active material due to the charge / discharge cycle, stress may be generated in the secondary particles, and a gap may be formed inside the secondary particles. In this case, it was found that the electron conduction is interrupted by the gap formed in the secondary particles, the conductivity is lowered, and the effect of improving the conductivity is not so great.

In Patent Document 2, an active material such as LiMn ₂ O ₄ and Li ₄ Ti ₅ O ₁₂ and an organic material that is carbonized by heating such as polyvinyl alcohol are wet mixed, and then dried and crushed to form a mixed powder of uniform composition, This mixed powder is fired in the atmosphere at a temperature of 1,000 ° C. or less to prepare an active material whose surface is covered with a carbon material. During firing, the generated carbon material is oxidized and has high conductivity. There are problems that cannot be obtained, and that it is difficult to uniformly carbonize the organic substance on the active material and to control the coating amount to be constant.

  Further, in Patent Document 3, a positive electrode active material secondary particle pulverized to a primary particle diameter is added to an acetylene black dispersion, or a positive electrode active material and acetylene black are added to a solvent to form a positive electrode Disclosed are secondary particles composed of primary particles of positive electrode active material whose surface is covered with acetylene black by drying a slurry prepared by simultaneously grinding to active material primary particle size and dispersing acetylene black. .

  In this document, a binder and a surfactant are used when acetylene black is dispersed. However, in this method, since the surfactant generally has a weak adsorption force to carbon black, if the surfactant is not sufficiently adsorbed to carbon black, the aggregate of the structure of the carbon black particles is solved. In addition, since the active material and acetylene black are coated with a binder and a surfactant, it is difficult to form an effective conductive coating with acetylene black on the active material. The improvement effect was not acquired.

  In Patent Document 4, positive electrode active material particles and carbon black as a conductive auxiliary agent are dispersed in an alcohol by a homogenizer, and then the alcohol is evaporated and baked to combine the positive electrode active material particles and the carbon black. Positive electrode active material secondary particles are produced, but carbon black is not sufficiently dispersed by homogenizer alone, so the carbon material is agglomerated on the active material and effective on the active material. It was considered difficult to form a conductive coating, and a sufficient conductivity improving effect was not obtained.

  In Patent Document 5, the solvent is removed from a slurry obtained by dispersing the positive electrode active material and carbon black in a solvent until the state where the positive electrode active material and carbon black are forcibly dispersed, thereby obtaining composite particles containing the positive electrode active material and carbon black. A method is disclosed.

  In this document, as a method for forcibly dispersing carbon black and a positive electrode active material, it is preferable to use a polymer dispersant as a dispersant in order to disperse carbon black appropriately. However, this method improves the dispersibility of carbon black, but has a large specific surface area. When fine carbon black is dispersed, a large amount of dispersed resin is required, and a dispersed resin having a large molecular weight is required. Since the surface of the carbon black is covered, the conductive network is hindered and the resistance of the electrode is increased. As a result, the effect of improving the dispersion of the carbon black may be offset.

  In Patent Document 6, primary particles in which conductive particles are attached to the surface of a lithium manganese composite oxide are obtained by precipitating a lithium manganese composite oxide precursor in an aqueous solution in which a carbon material is dispersed and aging the precursor. Aggregating to form secondary particles is disclosed.

  In this document, it is described that the dispersion of the carbon material in the aqueous solution follows only a normal method by shearing force using ultrasonic dispersion or a homogenizer. However, since both carbon blacks are hydrophobic, carbon black forms aggregates in the aqueous dispersion in such a method, so that uniform and thin carbon black adheres to the surface of the active material particles. In order to obtain a sufficient conductivity improvement effect for the active material itself, it is necessary to increase the amount of carbon black attached, resulting in a decrease in charge / discharge capacity per unit weight of the active material. It was.

  On the other hand, a similar approach has been attempted for the negative electrode. For example, in Patent Document 7, in a secondary battery using a lithium occluding alloy as a negative electrode active material, the surface of the negative electrode active material is covered with a layer made of carbon. By doing so, the charge loss at the time of charge / discharge is reduced, and the charge / discharge efficiency is improved.

  In this document, a method of using a CVD process when coating a layer made of carbon, or a method of firing after coating the surface of an alloy particle serving as a substrate with an organic substance is used. There was a problem that it was difficult to uniformly carbonize organic matter on the material and to control the coating amount to be constant.

  In Patent Document 8, since a lithium titanate compound having an average primary particle diameter of 1 μm or less can be used, the lithium ion diffusion time can be shortened and the specific surface area can be widened. It is said that a high active material utilization rate can be obtained even when discharging is performed. Also in this case, carbon materials such as acetylene black, carbon black, coke, carbon fiber, and graphite are used as a conductive agent for suppressing contact resistance with the current collector.

  In this document, a carbon material having an average particle size of 0.4 μm is blended as a conductive agent, and an active material dispersion slurry is prepared by a ball mill, but the primary particles of lithium titanate are less aggregated and uniformly dispersed. However, there is no mention of the dispersion of the carbon material, and since the particle diameters of the active material and the carbon material are approximately the same, a conductive path by an effective carbon material is not formed, It seems that the ability of the active material is not fully drawn out.

  Furthermore, an improvement in the wettability of the electrode with respect to the electrolytic solution is an important factor for improving the efficiency of charging and discharging together with the sufficient improvement in electrode conductivity. Since the electrode reaction occurs at the contact interface between the electrode material surface and the electrolytic solution, it is important that the electrolytic solution penetrates into the electrode and the electrode material is well wetted. As a method of promoting the electrode reaction, a method of increasing the surface area of the electrode by using a fine active material or a conductive auxiliary agent has been studied. There is a problem that it is difficult to improve battery performance because the contact area of the battery does not increase.

As a method for improving the wettability of an electrode, Patent Document 9 discloses a method of providing fine voids between active material particles by including carbon fibers having a fiber diameter of 1 to 1000 nm in the electrode. . However, since carbon fibers are usually intertwined in a complicated manner, uniform dispersion is difficult, and a uniform electrode cannot be produced simply by mixing carbon fibers. In addition, the same document also mentions a method of using carbon fiber whose surface is oxidized for dispersion control. However, when carbon fiber is directly oxidized, the conductivity and strength of the carbon fiber decrease. There is a problem of end up.
JP 09-092265 A (Patent No. 3601124) JP 2000-251888 A JP 11-329504 A JP 2004-134255 A JP 2008-034378 A (Patent No. 4102848) JP 2001-328813 A Japanese Patent Laid-Open No. 10-32226 (Patent No. 386525) JP 2005-317512 A (Patent No. 3769291) Japanese Patent Laying-Open No. 2005-063955

In view of the above problems, the present invention covers the surface of an active material for a battery electrode with a carbon material dispersed without impeding conductivity, thereby reducing the conductive aid and reducing the conductivity of the active material in the electrode. It is an object to provide a battery electrode composite material that is compatible with maintaining the contact property between an auxiliary agent and a conductive auxiliary agent and further has improved wettability with respect to an electrolytic solution.

  As a result of diligent studies to achieve the above object, the present inventors have found that "an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a base Mixing a dispersion in which a conductive carbon material is dispersed using as an dispersing agent one or more derivatives selected from the group consisting of triazine derivatives having a functional functional group, and then drying the mixture. In a battery made by using a composite material obtained by removing the solvent by coating the surface of the active material for the battery electrode with a carbon material, the battery output is increased and the amount of the conductive auxiliary agent is reduced. The inventors have found the effect of increasing the capacity and have made the present invention.

  The battery electrode composite material of the present invention can be used for lithium ion secondary batteries, nickel metal hydride secondary batteries, nickel cadmium secondary batteries, alkaline manganese batteries, lead batteries, fuel cells, capacitors, etc. It is suitable for use in a secondary battery.

  That is, the present invention includes at least one carbon material, an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, as a dispersant for the carbon material, and The present invention relates to a method for producing a composite material for battery electrodes, wherein the surface of the electrode active material is coated with one or more derivatives selected from the group consisting of triazine derivatives having a basic functional group.

The present invention also provides a battery electrode comprising: a dispersion in which at least one carbon material is dispersed in a solvent using a dispersant; and an electrode active material, and then the solvent is removed. The present invention relates to a method for manufacturing a composite material.
The present invention also relates to the above method for producing a composite material for battery electrodes, wherein the dispersion contains a derivative having an acidic functional group and a base having a molecular weight of 500 or less as a dispersion aid.
The present invention also relates to the above method for producing a composite material for battery electrodes, wherein the dispersion contains a derivative having a basic functional group and an acid having a molecular weight of 300 or less as a dispersion aid.
The present invention also relates to a method for producing a battery electrode composite material according to claim 3 or 4, wherein the dispersion aid is removed together with the solvent.

In addition, the present invention relates to the above-described method for producing a battery electrode composite material, wherein the dispersed particle diameter (D50) of the carbon material in the dispersion is 2 μm or less.
Moreover, this invention relates to the composite material for battery electrodes manufactured by said manufacturing method.
Further, the present invention is characterized in that the primary particle diameter of the carbon material is 10 to 100 nm, the above composite material for battery electrodes, the present invention also includes the above composite material for battery electrodes, a solvent, The present invention relates to an electrode mixture paste comprising a binder component.
The present invention also relates to the above-mentioned electrode mixture paste further comprising a conductive additive component.

In addition, the present invention provides a battery electrode, wherein an electrode mixture layer is formed on the current collector using the battery electrode composite material or the electrode mixture paste described above. About.
The present invention is a lithium ion secondary battery comprising a positive electrode having a positive electrode mixture layer on a current collector, a negative electrode having a negative electrode mixture layer on the current collector, and an electrolyte containing lithium. In addition, the present invention relates to a lithium ion secondary battery, wherein at least one of a positive electrode and a negative electrode is the battery electrode.

  According to a preferred embodiment of the present invention, since the battery electrode made of the active material composite material for the electrode can obtain high conductivity with a small amount of conductive auxiliary agent, the battery performance of, for example, a lithium ion secondary battery can be obtained. Overall improvement can be achieved.

The composite material for battery electrodes in the present invention includes an active material for electrodes, an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a base as a dispersant. After mixing with a conductive carbon material dispersion using one or more derivatives selected from the group consisting of triazine derivatives having a functional functional group, the mixture is dried to remove the solvent and thereby remove the surface of the active material Is covered with a carbon material, which will be described in detail below.
<Carbon material>
The carbon material in the present invention is not particularly limited as long as it is a conductive carbon material. Two or more types can be used in combination. From the viewpoint of conductivity, availability, and cost, it is preferable to use carbon black.

  Carbon black is a furnace black produced by continuously pyrolyzing a gas or liquid raw material in a reactor, especially ketjen black using ethylene heavy oil as a raw material. Channel black that has been rapidly cooled and precipitated, thermal black obtained by periodically repeating combustion and thermal decomposition using a gas as a raw material, and particularly various types such as acetylene black using an acetylene gas as a raw material alone or 2 More than one type can be used in combination. Ordinarily oxidized carbon black, hollow carbon and the like can also be used.

  Carbon black used as a conductive aid can also be oxidized carbon. The oxidation treatment of carbon is performed by treating carbon at a high temperature in the air or by secondary treatment with nitric acid, nitrogen dioxide, ozone, etc., for example, such as phenol group, quinone group, carboxyl group, carbonyl group. This is a treatment for directly introducing (covalently bonding) an oxygen-containing polar functional group to the carbon surface, and is generally performed to improve the dispersibility of carbon. However, since it is common for the conductivity of carbon to fall, so that the introduction amount of a functional group increases, it is preferable to use the carbon which has not been oxidized.

As the specific surface area of the carbon black used increases, the number of contact points between the carbon blacks increases, which is advantageous in reducing the internal resistance of the electrode. Specifically, the specific surface area (BET) determined from the adsorption amount of nitrogen is 20 m ² / g or more and 1500 m ² / g or less, preferably 50 m ² / g or more and 1500 m ² / g or less, more preferably 100 m ^2. / G or more and 1500 m ² / g or less are desirable. When carbon black having a specific surface area of less than 20 m ² / g is used, it may be difficult to obtain sufficient conductivity, and carbon black of more than 1500 m ² / g may be difficult to obtain from commercially available materials. is there.

  The particle size of the carbon black to be used is preferably 0.005 to 1 [mu] m, and particularly preferably 0.01 to 0.1 [mu] m in terms of primary particle size. However, the primary particle diameter here is an average of the particle diameters measured with an electron microscope or the like.

Examples of commercially available carbon black include furnace black manufactured by Tokai Carbon Co., Ltd. such as Toka Black # 4300, # 4400, # 4500, and # 5500; , And 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc., Colombian Furnace Black, such as PUER BLACK100, 115, and 205, # 2350, # 2400B, # 2600B, # 30050B, # 3030B, # 3230B, # 3350B # 3400B, # 5400B and other furnace black manufactured by Mitsubishi Chemical Corporation, MONARCH1400, 1300, 900, VulcanXC- Furnace Black from Cabot, such as 2R and BlackPearls2000, Furnace Black from TIMCAL, such as Ensaco 250G, Ensaco 260G, Ensaco 350G, and SuperP-Li, Ketjen Black from Akzo, such as Ketjen Black EC-300J, and EC-600JD, And acetylene black by Denki Kagaku Kogyo Co., Ltd., such as Denka Black, Denka Black HS-100, FX-35, etc. are mentioned, However, It is not limited to these.
<Dispersant>
Examples of the carbon material dispersant in the present invention include “an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a triazine derivative having a basic functional group. One or more derivatives selected from the group consisting of:

[Various derivatives with acidic functional groups]
As the derivative having an acidic functional group in the present invention, one or more kinds selected from organic dye derivatives having an acidic functional group or triazine derivatives having an acidic functional group are used. In particular, use of a triazine derivative represented by the following general formula (1) or an organic dye derivative represented by the general formula (4) is preferable.

  General formula (1):

In general formula (1),
X ¹⁰¹ _{is, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH-, or ^-X 103 ^-Y 101 ^{-X 104} - a and,
X ¹⁰² and X ¹⁰⁴ are each independently —NH— or —O—;
X ¹⁰³ _{is, -CONH -, - SO 2 NH} -, - CH 2 NH -, - NHCO-, or -NHSO ₂ - and is,
Y ¹⁰¹ is an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent.
Z ¹⁰¹ is —SO ₃ M, —COOM, or —P (O) (— OM) ₂ ;
M ¹⁰¹ is one equivalent of a monovalent to trivalent cation,
Q ^{101 is, -O-R 102, -NH-} R 102, halogen ^group, -X ^{101 -R 101,} or a ^-X 102 ^{-Y 101 -Z} 101,
R ¹⁰² is a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent,
n ¹⁰¹ is an integer of 1 to 4,
R ¹⁰¹ represents an organic dye residue, a heterocyclic residue which may have a substituent, an aromatic ring residue which may have a substituent, or a group represented by the following general formula (2) It is.
General formula (2):

In general formula (2),
X ²⁰¹ is —NH— or —O—;
X ^202, and ^{X 203} each independently, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH-, or a _-CH 2 NHCOCH ₂ NH-,
R ²⁰¹ and R ²⁰² are each independently an organic dye residue, an optionally substituted heterocyclic residue, an optionally substituted aromatic ring residue, or —Y ^201. -Z ²⁰¹ ,
Y ²⁰¹ is an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, which has 1 to 20 carbon atoms,
Z ²⁰¹ is —SO ₃ M ²⁰¹ , —COOM ²⁰¹ , or —P (O) (— OM ²⁰¹ ) ₂ ;
^M201 is one equivalent of a trivalent cation.

Examples of the organic dye residue represented by R ^{101 in the} general formula (1) and R ²⁰¹ and R ²⁰² in the general formula (2) include azo dyes such as diketopyrrolopyrrole dyes, azo, disazo, and polyazo. Anthraquinone dyes such as phthalocyanine dyes, diaminodianthraquinones, anthrapyrimidines, flavantrons, anthanthrones, indantrons, pyrantrons, violanthrones, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes Examples thereof include dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, and metal complex dyes. In particular, in order to increase the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye, among which an azo dye, a diketopyrrolopyrrole dye, a metal-free phthalocyanine dye, The use of a quinacridone dye or a dioxazine dye is preferable because of excellent dispersibility.

Examples of the heterocyclic residue and the aromatic ring residue represented by R ^{101 in the} general formula (1), R ^{201 in the} general formula (2), and R ²⁰² include, for example, thiophene, furan, pyridine, pyrazole, pyrrole, Examples include imidazole, isoindoline, isoindolinone, benzimidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, or anthraquinone. In particular, the use of a heterocyclic residue containing at least one of S, N, and O heteroatoms is preferable because of excellent dispersibility.

Y ^{101 in the} general formula (1) and Y ²⁰¹ in the general formula (2) represent an alkylene group, an alkenylene group or an arylene group which may have a substituent having 20 or less carbon atoms, but are preferably substituted. Examples thereof include a phenylene group, a biphenylene group, a naphthylene group, and an alkylene group which may have a side chain having 10 or less carbon atoms.

The alkyl group or alkenyl group which may have a substituent represented by R ¹⁰² contained in Q ¹⁰¹ of the general formula (1) is preferably one having 20 or less carbon atoms, and more preferably having a carbon number. The alkyl group which may have 10 or less side chains is mentioned. An alkyl group or alkenyl group having a substituent is a group in which a hydrogen atom of an alkyl group or an alkenyl group is substituted with a halogen group such as a fluorine atom, a chlorine atom, or a bromine atom, a hydroxyl group, or a mercapto group It is.

M ^{101 in the} general formula (1) and M ^{201 in the} general formula (2) represent one equivalent of a valence of 1 to 3, and are, for example, any one of a hydrogen atom (proton), a metal cation, or a quaternary ammonium cation. Represents. Moreover, when it has two or more M in a dispersing agent structure, M may be only any one of a proton, a metal cation, or a quaternary ammonium cation, and these may be combined.

  Examples of the metal include lithium, sodium, potassium, calcium, barium, magnesium, aluminum, nickel, and cobalt.

  The quaternary ammonium cation is a single compound having a structure represented by the general formula (3) or a mixture.

  General formula (3):

In General Formula (3), R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ have hydrogen, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a substituent. Any of the aryl groups that may be present.

R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ in the general formula (3) may be the same or different. Moreover, when R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ have a carbon atom, the number of carbon atoms is 1 to 40, preferably 1 to 30, and more preferably 1 to 20. If the carbon number exceeds 40, the conductivity of the electrode may be reduced.

  Specific examples of the quaternary ammonium include dimethylammonium, trimethylammonium, diethylammonium, triethylammonium, hydroxyethylammonium, dihydroxyethylammonium, 2-ethylhexylammonium, dimethylaminopropylammonium, laurylammonium, and stearylammonium. However, it is not limited to these.

  General formula (4):

In general formula (4),
X ^401, a direct _{bond, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH -, - X 402 -Y-, or ^{-X 402} - YX ^403- ,
X ⁴⁰² _{is, -CONH -, - SO 2 NH} -, - CH 2 NH -, - NHCO-, or -NHSO ₂ - and is,
X ⁴⁰³ is —NH— or —O—;
Y ⁴⁰¹ is an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, having 1 to 20 carbon atoms,
Z ⁴⁰¹ is —SO ₃ M ⁴⁰¹ , —COOM ⁴⁰¹ , or —P (O) (— OM ⁴⁰¹ ) ₂ ;
M ⁴⁰¹ is one equivalent of a monovalent to trivalent cation,
R ⁴⁰¹ is an organic dye residue,
n ⁴⁰¹ is an integer of 1 to 4.

Examples of the organic dye residue represented by R ⁴⁰¹ in the general formula (4) include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, and flavantrons. , Antanthrone, Indanthrone, Pyrantron, Biolantron, etc. Anthraquinone dyes, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone And dyes based on selenium, selenium, and metal complexes. The organic dye residue represented by R ₉ includes a light yellow anthraquinone residue that is not generally called a dye. In particular, in order to increase the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye, among which an azo dye, a diketopyrrolopyrrole dye, a metal-free phthalocyanine dye, The use of a quinacridone dye or a dioxazine dye is preferable because of excellent dispersibility.

M ^{401 in} the formula of the general formula (4) represents one equivalent of a monovalent to trivalent cation, for example, a hydrogen atom (proton), a metal cation, or a quaternary ammonium cation. When Ar has two or more M dispersant structure, M ⁴⁰¹ is a proton, metal cation or quaternary ammonium may be only one of a cation, or a combination thereof.

  Examples of the metal include lithium, sodium, potassium, calcium, barium, magnesium, aluminum, nickel, and cobalt.

  The quaternary ammonium cation is a single compound having a structure represented by the general formula (3) or a mixture.

  General formula (3):

In General Formula (3), R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ have hydrogen, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a substituent. Any of the aryl groups that may be present.

R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ in the general formula (3) may be the same or different. Moreover, when R ³⁰¹ , R ³⁰² , R ³⁰³ , and R ³⁰⁴ have a carbon atom, the number of carbon atoms is 1 to 40, preferably 1 to 30, and more preferably 1 to 20. If the carbon number exceeds 40, the conductivity of the electrode may be reduced.

Specific examples of the quaternary ammonium include dimethylammonium, trimethylammonium, diethylammonium, triethylammonium, hydroxyethylammonium, dihydroxyethylammonium, 2-ethylhexylammonium, dimethylaminopropylammonium, laurylammonium, and stearylammonium. However, it is not limited to these.
The method for synthesizing the dispersing agent is not particularly limited. For example, JP-B-39-28884, JP-B-45-11026, JP-B-45-29755, JP-B-64-5070 are disclosed. It can synthesize | combine by the method described in gazette or Unexamined-Japanese-Patent No. 2004-217842.

  Among the dispersants of the present invention, for example, those having a sulfonic acid or a salt thereof as an acidic functional group are generally sulfonated using a sulfonating agent such as fuming sulfuric acid, concentrated sulfuric acid, and chlorosulfonic acid. is there. In this case, the number of acidic functional groups has a distribution and can be, for example, a mixture of unsubstituted, monosubstituted, disubstituted, and the like. Not only sulfonic acid and its salts, but also carboxylic acid and phosphoric acid may be a mixture of those having different numbers of acidic functional groups depending on the synthesis method. As the dispersant of the present invention, it is also possible to use a mixture of those having different numbers of acidic functional groups.

[Various derivatives with basic functional groups]
As the derivative having a basic functional group in the present invention, one or more kinds selected from the group consisting of an organic dye derivative having a basic functional group and a triazine derivative having a basic functional group are used. In particular, use of a triazine derivative represented by the following general formula (5) or an organic dye derivative represented by the general formula (10) is preferable.

  General formula (5):

In general formula (5),
X ⁵⁰¹ is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH-, or -X ⁵⁰² -Y ⁵⁰¹ -X ⁵⁰³ - a and,
X ⁵⁰² is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- or, -NHSO ₂ - and is,
X ⁵⁰³ is independently —NH— or —O—,
Y ⁵⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
P ⁵⁰¹ is a substituent represented by any of the following general formulas (6), (7) or (8),
Q ⁵⁰¹ is represented by —O—R ⁵⁰² , —NH—R ⁵⁰² , a halogen group, —X ⁵⁰¹ —R ⁵⁰¹ or any one of the following general formulas (6), (7), or (8). A substituent,
R ⁵⁰² is a hydrogen atom, a substituent alkyl group which may have a substituted or be an alkenyl group, an aryl group which may have a substituent,
R ⁵⁰¹ is an organic dye residue, a heterocyclic residue which may have a substituent, an aromatic ring residue which may have a substituent, or a group represented by the following general formula (9) Yes,
n ⁵⁰¹ is an integer of 1 to 4.

  General formula (6):

In general formula (6),
X ⁶⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁶⁰² -Y ⁶⁰¹ -X ⁶⁰³ - a and,
X ⁶⁰² is —NH— or —O—;
X ⁶⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁶⁰¹ is an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, having 1 to 20 carbon atoms.
v is an integer of 1 to 10, and R ⁶⁰¹ And R ⁶⁰² each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ⁶⁰¹ And R ⁶⁰² together with an optionally substituted heterocyclic residue containing a nitrogen, oxygen or sulfur atom.

  General formula (7):

In general formula (7),
X ⁷⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁷⁰² -Y ⁷⁰¹ -X ⁷⁰³ - a and,
X ⁷⁰² is —NH— or —O—;
X ⁷⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁷⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
R ⁷⁰¹ And R ⁷⁰² each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or, R ⁷⁰¹ And R ⁷⁰² together may be an optionally substituted heterocyclic residue containing an additional nitrogen, oxygen or sulfur atom.

  General formula (8):

In general formula (8),
X ⁸⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁸⁰² -Y ⁸⁰¹ -X ⁸⁰³ - a and,
X ⁸⁰² is —NH— or —O—;
X ⁸⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁸⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
R ⁸⁰¹ , R ⁸⁰² , R ⁸⁰³ Each of R ⁸⁰⁴ is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁸⁰⁵ is an ^optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.

  General formula (9):

In general formula (9),
T ⁹⁰¹ is -X ⁹⁰² -R ⁹⁰¹ or W ⁹⁰¹ ,
U ⁹⁰¹ is -X ⁹⁰³ -R ⁹⁰² or W ⁹⁰² ;
W ⁹⁰¹ and W ⁹⁰² are each independently represented by —O—R ⁹⁰³ , —NH—R ⁹⁰³ , a halogen group, or any one of General Formula (6), (7), or General Formula (8). A substituent,
R ⁹⁰³ is a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or an aryl group that may have a substituent,
X ⁹⁰¹ is —NH— or —O—;
X ^902, and X ⁹⁰³ each independently, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH- or a -CH ₂ NHCOCH ₂ NH-,
Y ⁹⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
R ⁹⁰¹ and R ⁹⁰² are each independently an organic dye residue, a heterocyclic residue which may have a substituent, or an aromatic ring residue which may have a substituent.

Examples of the organic dye residue represented by R ⁵⁰¹ of the general formula (5) and R ⁹⁰¹ and R ⁹⁰² of the general formula (9) include azo such as diketopyrrolopyrrole dye, azo, disazo, polyazo and the like. Dyes, phthalocyanine dyes, diaminodianthraquinones, anthrapyrimidines, flavantrons, anthanthrones, indantrons, pyrantrons, violanthrones, anthraquinone dyes, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, Examples thereof include thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, and metal complex dyes. In particular, in order to enhance the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye.

Examples of R ^{501 in the} general formula (5) and R ⁹⁰¹ and R ⁹⁰² in the general formula (9) include heterocyclic residues and aromatic ring residues, such as thiophene, furan, pyridine, pyrazine, Examples include triazine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone, and acridone. It is done. These heterocyclic residues and aromatic ring residues are alkyl groups (methyl group, ethyl group, butyl group, etc.), amino groups, alkylamino groups (dimethylamino group, diethylamino group, dibutylamino group, etc.), Nitro group, hydroxyl group, alkoxy group (methoxy group, ethoxy group, butoxy group, etc.), halogen (chlorine, bromine, fluorine, etc.), phenyl group (alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy) Group, or may be substituted with a halogen, etc.), and a phenylamino group (which may be substituted with an alkyl group, an amino group, an alkylamino group, a nitro group, a hydroxyl group, an alkoxy group, or a halogen), etc. You may have the substituent of.

R ⁶⁰¹ , R ⁶⁰² , R ⁷⁰¹ and R ⁷⁰² in the general formulas (6) and (7) are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, An optionally substituted aryl group, or an optionally substituted heterocyclic residue comprising R ⁶⁰¹ and R ⁶⁰² or R ⁷⁰¹ and R ⁷⁰² together with an additional nitrogen, oxygen or sulfur atom It is.

Y ⁵⁰¹ , Y ⁶⁰¹ , Y ⁷⁰¹ , Y ⁸⁰¹ and Y ⁹⁰¹ in the general formulas (5) to (9) are each independently an alkylene group or an alkenylene group which may have a substituent having 20 or less carbon atoms. Alternatively, an arylene group, which may be substituted, may preferably be a phenylene group, a biphenylene group, a naphthylene group, or an alkylene group that may have a side chain having 10 or less carbon atoms.

  General formula (10):

In general formula (10),
Z ¹⁰⁰¹ is at least one selected from the group represented by the following general formulas (6), (7) and (8),
n ¹⁰⁰¹ is an integer of 1 to 4,
R ¹⁰⁰¹ is an organic dye residue, a heterocyclic residue which may have a substituent, or an aromatic residue which may have a substituent.

  General formula (6):

In general formula (6),
X ⁶⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁶⁰² -Y ⁶⁰¹ -X ⁶⁰³ - a and,
X ⁶⁰² is —NH— or —O—;
X ⁶⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁶⁰¹ is an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, having 1 to 20 carbon atoms.
v is an integer of 1 to 10, and R ⁶⁰¹ And R ⁶⁰² each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ⁶⁰¹ And R ⁶⁰² together with an optionally substituted heterocyclic residue containing a nitrogen, oxygen or sulfur atom.

  General formula (7):

In general formula (7),
X ⁷⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁷⁰² -Y ⁷⁰¹ -X ⁷⁰³ - a and,
X ⁷⁰² is —NH— or —O—;
X ⁷⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁷⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
R ⁷⁰¹ And R ⁷⁰² each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or, R ⁷⁰¹ And R ⁷⁰² together may be an optionally substituted heterocyclic residue containing an additional nitrogen, oxygen or sulfur atom.

  General formula (8):

In general formula (8),
X ⁸⁰¹ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ⁸⁰² -Y ⁸⁰¹ -X ⁸⁰³ - a and,
X ⁸⁰² is —NH— or —O—;
X ⁸⁰³ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or, -CH ₂ - is,
Y ⁸⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
R ⁸⁰¹ , R ⁸⁰² , R ⁸⁰³ Each of R ⁸⁰⁴ is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁸⁰⁵ is an ^optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.

Examples of the organic dye residue represented by R ¹⁰⁰¹ in formula (10) include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, and polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, and flavan. Anthraquinone dyes such as Throne, Antanthrone, Indanthrone, Pyrantron, Biolantron, Quinacridone dyes, Dioxazine dyes, Perinone dyes, Perylene dyes, Thioindigo dyes, Isoindoline dyes, Isoindolinone dyes, Examples thereof include quinophthalone dyes, selenium dyes, and metal complex dyes. In particular, in order to enhance the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye.

Examples of the heterocyclic residue and aromatic ring residue represented by R ¹⁰⁰¹ in the general formula (10) include thiophene, furan, pyridine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, and benzimidazo. Examples include Ron, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone, and acridone. These heterocyclic residues and aromatic ring residues are alkyl groups (such as methyl, ethyl, and butyl groups), amino groups, alkylamino groups (such as dimethylamino groups, diethylamino groups, and dibutylamino groups), Nitro group, hydroxyl group, alkoxy group (methoxy group, ethoxy group, butoxy group, etc.), halogen (chlorine, bromine, fluorine, etc.), phenyl group (alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy) Group, and optionally substituted with halogen, etc.), phenylamino group (which may be substituted with alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy group, halogen, etc.), etc. You may have the substituent of.

R ⁶⁰¹ , R ⁶⁰² , R ⁷⁰¹ and R ⁷⁰² in the general formulas (6) and (7) are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, An optionally substituted aryl group, or an optionally substituted heterocyclic residue comprising R ⁶⁰¹ and R ⁶⁰² or R ⁷⁰¹ and R ⁷⁰² together with an additional nitrogen, oxygen or sulfur atom It is.

Examples of the amine component used for forming the substituents represented by the general formulas (6) to (8) include:
Dimethylamine, diethylamine, methylethylamine, N, N-ethylisopropylamine, N, N-ethylpropylamine, N, N-methylbutylamine, N, N-methylisobutylamine, N, N-butylethylamine, N, N- tert-butylethylamine, diisopropylamine, dipropylamine, N, N-sec-butylpropylamine, dibutylamine, di-sec-butylamine, diisobutylamine, N, N-isobutyl-sec-butylamine, diamylamine, diisoamylamine, Dihexylamine, dicyclohexylamine, di (2-ethylhexyl) amine, dioctylamine, N, N-methyloctadecylamine, didecylamine, diallylamine, N, N-ethyl-1,2-dimethylpropylamine, , N-methylhexylamine, dioleylamine, distearylamine, N, N-dimethylaminomethylamine, N, N-dimethylaminoethylamine, N, N-dimethylaminoamylamine, N, N-dimethylaminobutylamine, N, N-diethylaminoethylamine, N, N-diethylaminopropylamine, N, N-diethylaminohexylamine, N, N-diethylaminobutylamine, N, N-diethylaminopentylamine, N, N-dipropylaminobutylamine, N, N-dibutyl Aminopropylamine, N, N-dibutylaminoethylamine, N, N-dibutylaminobutylamine, N, N-diisobutylaminopentylamine, N, N-methyl-laurylaminopropylamine, N, N-ethyl-hexylaminoe Ruamine, N, N-distearylaminoethylamine, N, N-dioleylaminoethylamine, N, N-distearylaminobutylamine, piperidine, 2-pipecoline, 3-pipecoline, 4-pipecoline, 2,4-rupetidin, 2,6-lupetidine, 3,5-lupetidine, 3-piperidinemethanol, pipecolic acid, isonipecotic acid, methyl isonicopetinate, ethyl isonicopetinate, 2-piperidineethanol, pyrrolidine, 3-hydroxypyrrolidine, N-aminoethylpiperidine, N -Aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidine, N-aminopropyl-2-pipecoline, N-aminopropyl-4-pipecoline, N-aminopropylmorpholine, N-methylpiperazine, N Butyl piperazine, N- methyl homopiperazine, 1-cyclopentylpiperazine, 1-amino-4-methylpiperazine, and 1-cyclopentyl piperazine and the like.

  The method for synthesizing the organic dye derivative having a basic functional group or the triazine derivative having a basic functional group according to the present invention is not particularly limited, but is described in JP-A No. 54-62227 and JP-A No. Sho. JP 56-118462, JP 56-166266, JP 60-88185, JP 63-305173, JP 3-2676, or JP 11-199796, etc. It can be synthesized by the method described in 1.

For example, after introducing a substituent represented by the general formula (11) to the general formula (14) into an organic dye, these substituent and an amine component (for example, N, N-dimethylaminopropylamine, N-methylpiperazine, It can be synthesized by reacting diethylamine, 4- [4-hydroxy-6- [3- (dibutylamino) propylamino] -1,3,5-triazin-2-ylamino] aniline, etc.).
Formula (11): —SO ₂ Cl
Formula (12): -COCl
Formula (13): —CH ₂ NHCOCH ₂ Cl
Formula (14): —CH ₂ Cl
For example, when introducing the substituent represented by the general formula (11), the organic dye is dissolved in chlorosulfonic acid and reacted with a chlorinating agent such as thionyl chloride. The number of substituents represented by the general formula (11) introduced into the organic dye can be controlled by conditions such as reaction time.

  In addition, when introducing the substituent represented by the general formula (12), first, an organic dye having a carboxyl group is synthesized by a known method, and then a chlorinating agent such as thionyl chloride in an aromatic solvent such as benzene. And the like.

  During the reaction of the substituent represented by the general formula (11) to the general formula (14) with the amine component, a part of the substituent represented by the general formula (11) to the general formula (14) is hydrolyzed to produce chlorine. May be substituted with a hydroxyl group. In that case, the substituent represented by the general formula (11) is a sulfonic acid group, and the substituent represented by the general formula (12) is a carboxylic acid group. A salt with a trivalent metal or the above amine may be formed.

  When the organic dye is an azo dye, a substituent represented by the general formulas (6) to (8) or the following general formula (15) is previously introduced into the diazo component or the coupling component, and then coupled. An azo organic dye derivative can also be produced by carrying out the reaction.

  Formula (15):

In general formula (15),
X ¹⁵⁰¹ is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH-, or -X ¹⁵⁰² -Y ¹⁵⁰¹ -X ¹⁵⁰³ - a and,
X ¹⁵⁰² is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO-, or -NHSO ₂ - and is,
Each X ¹⁵⁰³ is independently —NH— or —O—;
Y ¹⁵⁰¹ is an alkylene group which has 1 to 20 carbon atoms and may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent,
P ¹⁵⁰¹ is a substituent represented by any of the above general formulas (6), (7) or (8),
Q ¹⁵⁰¹ represents —O—R ¹⁵⁰¹ , —NH—R ¹⁵⁰¹ , a halogen group, —X ¹⁵⁰¹ —R ^1502, or a substituent represented by any of the above general formulas (6), (7), or (8) And
R ¹⁵⁰¹ is a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or an aryl group that may have a substituent,
R ¹⁵⁰² represents an organic dye residue, a heterocyclic residue which may have a substituent, an aromatic ring residue which may have a substituent, or a group represented by the general formula (9). is there.

  In addition, the triazine derivative having a basic functional group of the present invention uses, for example, cyanuric chloride as a starting material, and at least one chlorine of cyanuric chloride is represented by the above general formulas (6) to (8) or general formula (15). Reacting the amine component (eg, N, N-dimethylaminopropylamine, N-methylpiperazine, etc.) that forms the indicated substituents, and then reacting the remaining chlorine of cyanuric chloride with various amines, alcohols, etc. Obtained by.

  The dispersant of the present invention is considered to exhibit a dispersion effect by the action of the added dispersant on the surface of the carbon material (for example, adsorption). One or more selected from an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a triazine derivative having a basic functional group in a solvent. It is considered that the action of these dispersants on the carbon material proceeds by partially dissolving the carbon material and adding and mixing the carbon material in the solution. And, when the acidic functional group or basic functional group of the dispersant acting on the surface of the carbon material is polarized or dissociated, an electrical interaction (repulsive action) is induced, and the carbon material is deagglomerated. I think that the.

  Therefore, in the carbon material dispersion of the present invention, a good dispersion state can be obtained without directly introducing (covalently bonding) a functional group to the surface of the carbon material and without using a dispersion resin. For these reasons, a good dispersion state can be obtained without reducing the conductivity of the carbon material. By using the carbon material dispersion of the present invention in which the carbon material is well dispersed, a highly uniform composite material of the carbon material and the active material can be produced. In addition, the polarity of the acidic functional group or basic functional group introduced on the surface of the carbon material improves the wettability of the composite material of the carbon material and the active material with respect to the electrolyte, combined with the provision of uniformity due to the dispersion described above. I can expect that.

<Dispersing aid>
It is preferable to add a basic compound or an acidic compound as a dispersion aid to the carbon material dispersion of the present invention.

  When an organic dye derivative having an acidic functional group having an acidic functional group or a triazine derivative having an acidic functional group is used as a dispersing agent, it is preferable to add a basic compound as a dispersing aid.

  Although it does not specifically limit as a basic compound used at this time, Bases, such as salts produced by reaction of a metal hydroxide, such as an alkali metal, and a weak acid, and a strong base, ammonia, an amino-group containing organic compound, are mentioned. An amino group-containing organic compound is particularly preferable. Among them, it is preferable to use a basic compound that decomposes or volatilizes in the drying step when preparing the battery electrode composite material. In addition, since the present invention is characterized in that a good dispersion state is obtained without using a dispersion resin, that is, a high molecular weight dispersant, the molecular weight is preferably 500 or less, and more preferably 300 or less.

  These bases act with one or more basic functional groups selected from organic dye derivatives having acidic functional groups or triazine derivatives having acidic functional groups (for example, formation of ion pairs by neutralization (salt formation), and When the ion pair (salt) is polarized or dissociated, the solubility of these dispersants increases, and electrical interaction (eg, the surface of the carbon material) occurs on the surface of the carbon material on which these dispersants act (eg, adsorb). It is considered that the electrostatic repulsion between the dispersant anions adsorbed on the surface and the repulsive action by the electric double layer formed by the dissociated base cation are induced, and the deagglomeration of the carbon material is promoted.

Moreover, when using the organic pigment derivative which has a basic functional group, or the triazine derivative which has a basic functional group as a dispersing agent, it is preferable to add an acidic compound as a dispersing aid.
The acidic compound used at this time is not particularly limited, but includes hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, salts of inorganic compounds obtained by the reaction of strong acids and weak bases, organic acids such as carboxylic acids, phosphoric acids, and sulfonic acids. Can be used. Among them, it is preferable to use an acid that decomposes or volatilizes in the drying step when preparing the battery electrode composite material. Further, since the present invention is characterized by obtaining a good dispersion state without using a dispersion resin, that is, a high molecular weight dispersant, it is desirable to use an acid having a molecular weight of 300 or less, preferably 200 or less. Further, it is preferable to use an acid having low reactivity with the electrode active material described later, and organic acids, particularly carboxylic acids are particularly preferable. Specifically, for example, formic acid, ethanoic acid (acetic acid), fluoroacetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, acrylic acid, methacrylic acid, Examples include crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like.

  These acids react with one or more basic functional groups selected from organic dye derivatives having basic functional groups or triazine derivatives having basic functional groups (for example, formation of ion pairs by neutralization (salt formation) ), And ion pair (salt) polarization or dissociation, etc., the solubility of these dispersants increases, and electrical interaction (for example, on the surface of the carbon material on which these dispersants act (for example, adsorption)) Electrostatic repulsion between dispersant cations adsorbed on the surface of the carbon material, and repulsion by the electric double layer formed by dissociated acid anions) are induced, which seems to promote deagglomeration of the carbon material. .

<Solvent>
Examples of the solvent used in the present invention include alcohols, glycols, cellosolves, amino alcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, phosphorus Examples include, but are not limited to, acid esters, ethers, nitriles, and water. In addition, the solvent in the present invention includes a solvent used for preparing a composite material for battery electrodes and a solvent used for preparing a composite paste for electrodes. It may be a different solvent. Moreover, the mixture of two or more types of solvents may be sufficient.

  As a solvent used for producing the battery electrode composite material, it is preferable to use a polar solvent having a relative dielectric constant of 15 or more. The relative dielectric constant is one of the indices indicating the strength of the polarity of the solvent, and is described in Asahara et al., “Solvent Handbook” (Kodansha Scientific Co., Ltd., 1990).

  For example, methyl alcohol (dielectric constant: 33.1), ethyl alcohol (23.8), 2-propanol (18.3), 1-butanol (17.1), 1,2-ethanediol (38.66) ), 1,2-propanediol (32.0), 1,3-propanediol (35.0), 1,4-butanediol (31.1), diethylene glycol (31.69), 2-methoxyethanol ( 16.93), 2-ethoxyethanol (29.6), 2-aminoethanol (37.7), acetone (20.7), methyl ethyl ketone (18.51), formamide (111.0), N-methylformamide (182.4), N, N-dimethylformamide (36.71), N-methylacetamide (191.3), N, N-dimethylacetamide (3 .78), N-methylpropionamide (172.2), N-methylpyrrolidone (32.0), hexamethylphosphoric triamide (29.6), dimethyl sulfoxide (48.9), sulfolane (43.3), acetonitrile (37.5), propionitrile (29.7), water (80.1), and the like, but are not limited thereto.

In particular, the use of a polar solvent having a relative dielectric constant of 15 or more and 200 or less, preferably 15 or more and 100 or less, and more preferably 20 or more and 100 or less can provide good dispersion stability of the carbon material. preferable. Solvents with a relative dielectric constant of less than 15 often have a significant decrease in the solubility of the dispersant, and good dispersion cannot be obtained. Is often not obtained.
Moreover, it is necessary to select the solvent used in order to produce the battery electrode composite material in view of the reactivity with the active material. For example, lithium cobaltate, which is generally used as a positive electrode active material, reacts with lithium ions in the active material and water when water is used as a solvent, generating lithium hydroxide and the like on the surface, and as a binder Although there are problems such as deterioration of commonly used polyvinylidene fluoride and corrosion of current collector aluminum, carbon is generally used as the negative electrode active material. There is no problem. It is preferable to select a solvent having low reactivity in accordance with the active material to be used.
Although it does not specifically limit as a solvent for producing the composite paste for electrodes, The thing with high solubility with respect to the binder component mentioned later can be used. Again, it is preferable to select in consideration of the reactivity with the electrode active material.
<Carbon material dispersion and production method thereof>
A method for producing the carbon material dispersion used in the present invention will be described.

  The carbon material dispersion includes, for example, an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a triazine derivative having a basic functional group. It can manufacture by disperse | distributing the carbon material as a conductive support agent to a solvent in presence of 1 or more types of dispersing agents chosen.

  In the above production method, the dispersant used in the present invention is completely or partially dissolved in a solvent, and a carbon material as a conductive additive is added and mixed in the solution, whereby the dispersant is converted into a carbon material. It is preferable to disperse in a solvent while acting (for example, adsorption). The concentration of the carbon material in the dispersion at this time is preferably 1% by weight or more and 50% by weight or less, although it depends on the characteristic values of the carbon material such as the specific surface area and surface functional group amount of the carbon material used. More preferably, it is 5% by weight or more and 35% by weight or less. When the concentration of the carbon material is too low, the production efficiency is deteriorated, and when the concentration of the carbon material is too high, the viscosity of the dispersion is remarkably increased, and the dispersion efficiency and the handling property of the dispersion may be lowered.

  The addition amount of at least one dispersant selected from an organic dye derivative having an acidic functional group or a triazine derivative having an acidic functional group is determined by the specific surface area of the carbon material as the conductive auxiliary agent used. Generally, the dispersant is 0.5 to 40 parts by weight, preferably 1 to 35 parts by weight, more preferably 2 to 30 parts by weight with respect to 100 parts by weight of the carbon material. Add less than parts. If the amount of the dispersant is small, a sufficient dispersing effect cannot be obtained, and a sufficient wettability improving effect to the electrolytic solution cannot be obtained. Moreover, even if it adds excessively, the remarkable dispersion | distribution improvement effect is not acquired.

  The addition amount of one or more derivatives selected from the group consisting of an organic dye derivative having a basic functional group and a triazine derivative having a basic functional group is determined by the specific surface area of the carbon material as the conductive aid used Is done. Generally, at least one selected from the group consisting of organic dye derivatives having basic functional groups, anthraquinone derivatives having basic functional groups, acridone derivatives having basic functional groups, and triazine derivatives having basic functional groups The derivative is 0.5 parts by weight or more and 40 parts by weight or less, preferably 1 part by weight or more and 35 parts by weight or less, more preferably 2 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the carbon material. Added. If the addition amount is small, a sufficient dispersion effect cannot be obtained, and a wettability improvement effect to the electrolytic solution cannot be obtained sufficiently. Moreover, even if it adds excessively, the remarkable dispersion | distribution improvement effect may not be acquired.

  The dispersed particle size of the carbon material as the conductive assistant may be reduced to 0.03 μm or more and 2 μm or less, preferably 0.05 μm or more and 1 μm or less, more preferably 0.05 μm or more and 0.5 μm or less. desirable. It may be difficult to produce a dispersion in which the carbon material has a dispersed particle size of less than 0.03 μm. In addition, when an active material composite material is manufactured using a dispersion in which the dispersed particle size of the carbon material exceeds 2 μm, a composite paste is prepared to reduce the resistance distribution of the active material particles and to reduce the resistance. Occasionally, problems such as having to increase the amount of conductive additive added may occur. The dispersed particle size referred to here is a particle size (D50) that is 50% when the volume ratio of the particles is integrated from the fine particle size distribution in the volume particle size distribution. A particle size distribution meter such as a dynamic light scattering type particle size distribution meter ("Microtrack UPA" manufactured by Nikkiso Co., Ltd.).

  Moreover, as a device for dispersing the carbon material particles in the solvent while allowing the dispersing agent to act on the carbon material (for example, adsorption), a disperser usually used for pigment dispersion or the like can be used. For example, mixers such as dispersers, homomixers, planetary mixers, homogenizers ("Clearmix" manufactured by M Technique, PRIMIX "Fillmix", etc.), paint conditioners (manufactured by Red Devil), ball mills, sand mills ( Media type dispersers such as “Dynomill” manufactured by Shinmaru Enterprises, Inc.), Attritor, Pearl Mill (“DCP Mill” manufactured by Eirich), Coball Mill, etc., Wet Jet Mill (“Genus PY” manufactured by Genus, Sugino Machine Co., Ltd.) Media-less dispersers such as “Starburst” manufactured by Nanomizer, “Nanomizer” manufactured by Nanomizer, etc., “Claire SS-5” manufactured by M Technique, and “MICROS” manufactured by Nara Machinery Co., other roll mills, etc. It is not limited to. Moreover, as the disperser, it is preferable to use a disperser that has been subjected to a metal contamination prevention treatment from the disperser.

  For example, when using a media type disperser, a disperser in which the agitator and vessel are made of a ceramic or resin disperser, or the metal agitator and vessel surface are treated with tungsten carbide spraying or resin coating. Is preferably used. And as a media, it is preferable to use ceramic beads, such as glass beads, zirconia beads, and alumina beads, and among them, the use of zirconia beads is preferable. Moreover, also when using a roll mill, it is preferable to use a ceramic roll. Only one type of dispersion device may be used, or a plurality of types of devices may be used in combination.

  In addition, it is preferable to include a step of removing contaminants such as metal foreign matters when dispersing the carbon material particles. Carbon materials such as carbon black, graphite, and carbon fiber often contain metallic foreign matters derived from their manufacturing processes (as line contamination and catalysts). This is very important to prevent short circuit. In the present invention, due to the effect of the dispersant having a polar functional group, the aggregation of the carbon material particles is well loosened, and the viscosity of the dispersion is lowered. Therefore, in the dispersion, compared with the case where no dispersant is added. Even when the carbon material particle concentration is high, metallic foreign matters can be efficiently removed. Examples of methods for removing metallic foreign substances include iron removal with a magnet, filtration, and centrifugation.

<Active material for electrodes>
The positive electrode active material used in the present invention is not particularly limited, and metal oxides that can be doped or intercalated with lithium ions, metal compounds such as metal sulfides, and conductive polymers can be used. .

For example, lithium manganese composite oxide (for example, Li _x Mn ₂ O ₄ or Li _x MnO ₂ ), lithium nickel composite oxide (for example, Li _x NiO ₂ ), lithium cobalt composite oxide (Li _x Co ₂ ), lithium nickel cobalt composite oxides (e.g., _{Li x Ni 1-y Co y} O 2), lithium manganese cobalt composite oxides (e.g., _{Li x Mn y Co 1-y} O 2), lithium nickel manganese cobalt composite oxide (e.g., _Li x Ni _{1 / 3} Co _1/3 Mn _1/3 O ₂ ), composite oxide powder of lithium and transition metal such as spinel type lithium manganese nickel composite oxide (for example, Li _x Mn _2-y Ni _y O ₄ ), oripin structure lithium phosphorus oxide powder (e.g. _Li x FePO _{4 having, Li x Fe 1-y Mn} y PO 4, Li _x CoPO ₄ etc.), manganese oxide, iron oxide, copper oxide, nickel oxide, vanadium oxide (for example, V ₂ O ₅ , V ₆ O ₁₃ ), transition metal oxide powder such as titanium oxide, iron sulfate (Fe ₂ ( Examples thereof include transition metal sulfide powders such as SO ₄ ) ₃ ), TiS ₂ , and FeS.

  These positive electrode active materials can be used alone or in combination.

Although it does not specifically limit as a negative electrode active material used by this invention, It is a material which can dope or intercalate lithium ion, for example, alloys, such as metallic lithium, its alloy tin alloy, silicon alloy, lead alloy Type, lithium titanate (Li _{4 + x} Ti ₅ O ₁₂ ), iron oxide type (Li _x Fe ₂ O ₃ , Li _x Fe ₃ O ₄ ), tungsten oxide (Li _x WO ₂ , Li _x WO ₃ ), Metal oxides such as molybdenum oxide (Li _x MoO ₂ ), amorphous tin oxide, tin silicon oxide (SnSiO ₃ ), silicon oxide (SiO), titanium sulfide (TiS ₂ , LiTiS ₂ ), molybdenum sulfide (Li _x Metal sulfide systems such as MoS ₂ ) and iron sulfide (Li _x FeS ₂ ). Metal nitrides such as lithium cobalt nitride (Li _x Co _y N, 0 <x <4, 0 <y <0.5), conductive polymers such as polyacetylene and poly-p-phenylene, soft carbon, Amorphous carbonaceous material such as hard carbon, artificial graphite such as highly graphitized carbon material, carbonaceous powder such as natural graphite, carbon black, mesophase carbon black, resin-fired carbon material, gas-phase-grown carbon fiber, carbon fiber And carbon-based materials.
These negative electrode active materials can be used alone or in combination.

<Battery electrode composite material and method for producing the same>
The manufacturing method of the composite material for battery electrodes in this invention is demonstrated.
The battery electrode composite material is, for example, from the group consisting of an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a triazine derivative having a basic functional group. In the presence of one or more selected dispersants, a carbon material as a conductive aid and an electrode active material are mixed in a solvent, and then the processed product is dried to remove the solvent. Can do.
There is no restriction | limiting in particular in the addition order of various materials, For example, adding and mixing an active material, stirring the carbon material dispersion produced by the above-mentioned method. Also, a method of dispersing and mixing by adding a part or all of the active material simultaneously with the carbon material when the carbon material is dispersed in the solvent in the presence of the dispersant. Furthermore, a method of mixing a dispersion in which a carbon material is dispersed in a solvent in the presence of the dispersant and a dispersion in which an active material is dispersed in a solvent may be used. In particular, a method of adding an active material to a carbon material dispersion is preferable because good dispersion stability of the carbon material can be obtained.

  In the present invention, the electrode active material is desirably pulverized and pulverized to the primary particle size in advance, but there is no particular limitation on the means for pulverization and pulverization, for example, the pigment dispersion described above, etc. In general, a disperser generally used can be used, and it may be carried out under either wet or dry conditions. When wet processing is performed to pulverize and pulverize the active material, a dispersant used in the dispersion of the carbon material of the present invention may be added to stabilize the pulverized active material.

  As a device for mixing the carbon material and the electrode active material, a mixing / dispersing device usually used for mixing and dispersing pigments can be used. For example, mixers such as tumblers, shakers, mixers, V-type mixers; mixers such as dispersers, homomixers, Henschel mixers, or planetary mixers; “Clairemix” manufactured by M Technique, or PRIMIX Homogenizers such as “Filmix”; paint conditioner (manufactured by Red Devil), ball mill, sand mill (such as “Dynomill” manufactured by Shinmaru Enterprises), attritor, pearl mill (such as “DCP mill” manufactured by Eirich) Or media type dispersers such as coball mills; wet jet mills (“Genus PY” manufactured by Genus, “Starburst” manufactured by Sugino Machine, “Nanomizer” manufactured by Nanomizer, etc.), “Claire SS-5” manufactured by M Technique , Hybridizer (( ) Nara Machinery Co., Ltd.), Mechano Micros Co., Ltd. (Nara Machinery Co., Ltd.), Mechano Fusion System AMS (Hosokawa Micron Co., Ltd.), or “MICROS” manufactured by Nara Machinery Co., Ltd .; roll mill, kneader, stone mill type Although a mill etc. are mentioned, it is not limited to these. In the case of an active material in which particles are easily broken or crushed by a strong impact, a medialess disperser including a mixer or a homogenizer is preferable to a media disperser.

  In the method for producing a composite material for battery electrodes of the present invention, the method for drying and pulverizing the treated product includes the method of pulverizing the dried product obtained after hot air drying, or the method of pulverizing the dried product obtained after vacuum drying. Examples thereof include a method for crushing, a method for crushing a dried product obtained after freeze-drying, and a method for drying by spray drying. Of these various drying methods, the spray drying method does not require a means for crushing the dried product, and the size of the secondary particles can be adjusted, making granulation easy. Most preferred in some respects. Further, it is desirable to reduce the solvent content by filtration or filter press treatment before drying the slurry.

  Although the time for the drying treatment can be arbitrarily set depending on the apparatus to be used, it is preferable to set the drying conditions so that the dispersion aid can be removed together with the solvent when a dispersion aid is added in the preparation of the carbon material dispersion. This is to prevent the acid component and base component that are originally unnecessary for the battery from adversely affecting the active material for the electrode and the binder component (for example, elution of the active material component as a metal ion or a decrease in the resistance of the binder). Because.

  In the method for producing a composite material for battery electrodes of the present invention, in particular, the carbon material is uniformly and finely dispersed by the dispersant, and the polar functional group (acidic functional group or basic functional group) of the dispersant is included. Etc.), the affinity between the active material surface (especially active materials that are inorganic materials often have a polar surface) and the carbon material is expected to improve the surface of the active material for electrodes. It seems that the conductivity of the active material can be drastically improved by coating with a small amount of carbon material.

  In the present invention, the coating of the electrode active material surface means that the carbon material uniformly adheres to the surface of the active material particles as a thin film. Therefore, when the dispersion of the carbon material is insufficient, there is a non-uniformity in which there are portions where the secondary particles of the carbon material aggregated on the surface of the active material particles are attached, and portions where the surface is not attached and the surface is exposed This form is not considered a coating. It seems that electrode resistance distribution due to partial aggregation can be prevented by coating the active material with a carbon material.

  Also, the effect of the polar functional group of the dispersant improves the wettability of the battery electrode composite material with respect to the electrolyte solution, promotes the entry and exit of lithium ions between the composite material surface and the electrolyte solution, and increases the internal resistance of the battery. Is expected to be reduced.

  Furthermore, when the primary particles of the active material whose surface is coated with the carbon material are aggregated or consolidated to form secondary particles of the active material, the active material secondary particles are also effective due to the less carbon material. Since a conductive path can be formed, improvement in the conductivity and energy density of the active material is expected.

<Electrode paste for electrode and method for producing the same>
The composite material for battery electrodes of the present invention can be used for a positive electrode mixture or a negative electrode mixture. When used for a positive electrode mixture or a negative electrode mixture, it is preferable to add a binder component and a solvent and optionally a conductive additive to the battery electrode composite material and use it as an electrode mixture paste. The order of adding each component of the electrode mixture paste is not limited to this.

The ratio of the active material to the total solid content in the electrode mixture paste is preferably 80% by weight or more and 98.5% by weight or less. And the ratio of the binder component in the total solid content in the electrode mixture paste is preferably 0.5% by weight or more and 10% by weight or less. The proper viscosity of the electrode mixture paste depends on the method of applying the electrode mixture paste, but generally it is preferably 100 mPa · s or more and 30,000 mPa · s or less.
In the positive electrode mixture paste of the present invention, since the positive electrode active material is coated with a carbon material dispersed without impeding conductivity, excellent conductivity and adhesion can be imparted to the positive electrode mixture layer. In addition, since the amount of conductive additive added can be reduced by improving conductivity, the amount of positive electrode active material added can be relatively increased, and the capacity, which is an important characteristic of the battery, is increased. Can do.
In the negative electrode mixture paste according to the present invention, when a carbon material-based active material is used as the negative electrode active material, aggregation of the carbon material-based active material is also mitigated by the effect of the dispersant added for dispersing the conductive additive. Is done. Even when the negative electrode active material is not a carbon material, the carbon material particles (conducting aid) can be uniformly coordinated and adhered around the negative electrode active material, and the negative electrode mixture layer has excellent conductivity and adhesion. Can be granted.

<Binder>
The binder used for the production of the electrode mixture paste includes ethylene, propylene, vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, acrylonitrile, styrene, vinyl butyral, Polymer or copolymer containing vinyl acetal, vinyl pyrrolidone, etc. as a structural unit; polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, acrylic resin, formaldehyde resin, silicon resin , Fluororesins; cellulose resins such as carboxymethyl cellulose; rubbers such as styrene-butadiene rubber and fluororubber; conductive resins such as polyaniline and polyacetylene. Moreover, the modified body and mixture of these resin, and a copolymer may be sufficient. In particular, it is preferable to use a high molecular compound containing a fluorine atom in the molecule, for example, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene, etc. from the viewpoint of resistance.

Moreover, as for the weight average molecular weight of these resin as a binder, 10,000-1,000,000 are preferable. When the molecular weight is small, the resistance of the binder may decrease. When the molecular weight is increased, the resistance of the binder is improved, but the viscosity of the binder itself is increased and the workability is lowered.
<Conductive aid>
When the amount of the carbon material contained in the battery electrode composite material of the present invention is insufficient as the amount of the conductive additive component of the electrode mixture paste, it is preferable to further add a conductive additive. For example, a carbon material, a metal that is difficult to alloy with lithium, a conductive polymer material, and the like can be given. In consideration of the interaction with the dispersant used in the present invention, a carbon material is preferable. It does not specifically limit as a carbon material, The carbon material used for the carbon material dispersion of this invention may be the same, and a different thing may be used.

  In addition, when the carbon material dispersion of the present invention is used as an additional conductive auxiliary, the carbon material in the electrode mixture layer is uniformly dispersed and coordinated, so that there is an effect of improving conductivity with a small amount of addition. Is more preferable.

<Lithium ion secondary battery>
Next, a lithium ion secondary battery using the battery electrode composite material of the present invention will be described.
The lithium ion secondary battery includes a positive electrode having a positive electrode mixture layer on a current collector, a negative electrode having a negative electrode mixture layer on the current collector, and an electrolyte containing lithium.

  Regarding the electrode, the material and shape of the current collector to be used are not particularly limited, and as the material, metals and alloys such as aluminum, copper, nickel, titanium, and stainless steel are used. In particular, as the positive electrode material, aluminum is used as the negative electrode. The material is preferably copper. As the shape, a flat plate foil is generally used, but a roughened surface, a perforated foil shape, and a mesh shape can also be used.

  Examples of the method for forming the electrode mixture layer on the current collector include a method in which the electrode mixture paste is directly applied on the current collector and dried. 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.

There is no restriction | limiting in particular about the coating method, A well-known method can be used. Specific examples include a die coating method, a dip coating method, a roll coating method, a doctor coating method, a spray coating method, a gravure coating method, a screen printing method, and an electrostatic coating method. Moreover, you may perform the rolling process by a lithographic press, a calender roll, etc. after application | coating.
<Electrolyte>
As an electrolytic solution constituting the lithium ion secondary battery of the present invention, a solution in which an electrolyte containing lithium is dissolved in a non-aqueous solvent is used. As the electrolyte, 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 and the} like, but are not limited thereto.

  The non-aqueous solvent is not particularly limited, but carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, γ-butyrolactone, γ-valerolactone, and γ-octanoic lactone. Lactones such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,2-methoxyethane, 1,2-ethoxyethane, 1,2-dibutoxyethane, etc. Glymes, esters such as methyl formate, methyl acetate and methyl propionate, sulfoxides such as dimethyl sulfoxide and sulfolane, and nitriles such as acetonitrile. These solvents may be used alone or in combination of two or more.

  Furthermore, the electrolyte solution may be a gelled polymer electrolyte held in a polymer matrix. Examples of the polymer matrix include, but are not limited to, an acrylate resin having a polyalkylene oxide segment, a polyphosphazene resin having a polyalkylene oxide segment, a polysiloxane having a polyalkylene oxide segment, and the like.

  The structure of the lithium ion secondary battery using the battery electrode composite material 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 necessary, a paper type, a cylindrical type, Various shapes can be formed according to the purpose of use, such as a button type and a laminated type.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to an Example. In the examples, “parts” represents “parts by weight” and “%” represents “% by weight”.

  The carbon materials, dispersants, dispersion aids, solvents, and binders used in Examples and Comparative Examples are shown below.

<Carbon material>
Denka black HS-100 (manufactured by Denki Kagaku Kogyo): acetylene black, primary particle diameter 48 nm, specific surface area 39 m ² / g, hereinafter abbreviated as HS-100.
Denka black powder product (manufactured by Denki Kagaku Kogyo Co., Ltd.): Acetylene black, primary particle diameter 35 nm, specific surface area 68 m ² / g, hereinafter abbreviated as powder product.
Talker black # 5500 (manufactured by Tokai Carbon Co., Ltd.): Furnace black, primary particle diameter 25 nm, specific surface area 225 m ² / g, hereinafter abbreviated as # 5500.
Super-P Li (manufactured by TIMCAL): furnace black, primary particle size 40 nm, specific surface area 62 m ² / g.
EC-300J (manufactured by Akzo): Ketjen black, primary particle size 40 nm, specific surface area 800 m ² / g.

<Dispersant>
[Derivatives having acidic functional group (Aa) to (As)]
-Organic dye derivatives having acidic functional groups:
Ak, Al, Am, An, Ao, Ap, Aq, Ar, As
-Triazine derivatives with acidic functional groups:
Aa, Ab, Ac, Ad, Ae, Af, Ag, Ah, Ai, Aj
Tables 1 to 5 show various derivatives (Aa) to (As) having acidic functional groups.
[Derivatives having basic functional groups (Ba) to (Bo)]
-Organic dye derivatives having basic functional groups:
Ba, Bb, Bc, Bd, Be, Bf, Bg
-Triazine derivatives with basic functional groups:
Bh, Bi, Bj, Bk, Bl, Bm, Bn, Bo
Tables 6 to 9 show various derivatives (Ba) to (Bo) having basic functional groups.

  Hereinafter, organic dye derivatives having an acidic functional group, and triazine derivatives having an acidic functional group are abbreviated as derivatives having an acidic functional group, and organic dye derivatives having a basic functional group and triazines having a basic functional group. A derivative is abbreviated as a derivative having a basic functional group.

[Surfactant]
As the surfactant, a nonionic surfactant (Emulgen A-60, polyoxyethylene derivative, manufactured by Kao Corporation) or an anionic surfactant (Demol N, β-naphthalenesulfonic acid-formalin condensate sodium) Any of salt and Kao) was used.
[Dispersion resin]
As the dispersion resin, polyvinylpyrrolidone (weight average molecular weight: about 80,000, manufactured by Nippon Shokubai Co., Ltd.) was used.

<Dispersing aid>
[base]
Triethylamine: molecular weight 101 g / mol, boiling point 90 ° C., hereinafter abbreviated as TEA.
Dimethylaminoethanol: molecular weight 89 g / mol, boiling point 133 ° C., hereinafter abbreviated as DMAE.
[acid]
Acetic acid: molecular weight 60 g / mol, boiling point 118 ° C.
Methacrylic acid: molecular weight 86 g / mol, boiling point 160 ° C.

<Solvent>
N-methyl-2-pyrrolidone: boiling point 202 ° C., hereinafter abbreviated as NMP.
1,2-ethanediol: boiling point 198 ° C., hereinafter abbreviated as EG.
-Purified water: boiling point 100 ° C.
Acetone: boiling point 57 ° C.
Methanol: boiling point 65 ° C.

<Binder>
Polyvinylidene fluoride: KF polymer W1100 (manufactured by Kureha), hereinafter abbreviated as PVDF.
Styrene butadiene rubber: TRD2001 (manufactured by JSR), hereinafter abbreviated as SBR.
Carboxymethylcellulose: Sunrose F300MC (manufactured by Nippon Paper Chemicals), hereinafter abbreviated as CMC.

<Preparation of carbon dispersion for conductive aid>
[Carbon dispersions 1 to 23, 26]
According to the composition shown in Tables 10 and 11, various solvents and derivatives having an acidic functional group (any of dispersants Aa to As shown in Tables 1 to 5) are charged into a glass bottle, mixed and stirred, and the derivative is prepared. Completely or partially dissolved. Next, after adding the carbon material used as a conductive support agent and further adding zirconia beads as a medium, it was dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.
[Carbon dispersions 24, 25, 27 to 29]
In accordance with the composition shown in Table 10, various solvents, a derivative Aa having an acidic functional group shown in Table 1 as a dispersant, and various dispersion aids are added to a glass bottle, and mixed and stirred to completely or partially dissolve the derivative. It was. Next, after adding the carbon material used as a conductive support agent and further adding zirconia beads as a medium, it was dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.
[Carbon dispersion 30 to 45, 48, 49]
In accordance with the composition shown in Table 11, various solvents, a derivative having a basic functional group as a dispersing agent (any of dispersing agents Ba to Bo shown in Tables 6 to 9), and various dispersing aids are charged into a glass bottle and mixed. By stirring, the derivative was completely or partially dissolved. Next, after adding the carbon material used as a conductive support agent and further adding zirconia beads as a medium, it was dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.

[Carbon dispersions 46, 47, 50]
According to the composition shown in Table 11, various solvents and a derivative Ba having a basic functional group shown in Table 6 as a dispersant were charged in a glass bottle, mixed and stirred, and the derivative was completely or partially dissolved. Next, after adding the carbon material used as a conductive support agent and further adding zirconia beads as a medium, it was dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.
[Carbon dispersions 51 to 53]
According to the composition shown in Table 11, various solvents and a carbon material serving as a conductive additive were charged in a glass bottle, and zirconia beads were added as a medium, and then dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.
[Carbon dispersions 54 to 56]
According to the composition shown in Table 11, various solvents and a surfactant or a dispersing resin as a dispersing agent were charged into a glass bottle and mixed and stirred to completely or partially dissolve the dispersing agent. Next, after adding the carbon material used as a conductive support agent and further adding zirconia beads as a medium, it was dispersed with a paint shaker. The obtained dispersion was thoroughly stirred with a stirring blade equipped with a magnet, and then passed through a 20 μm filter to obtain various carbon dispersions.

  To measure the particle size distribution of the carbon dispersion, use a dynamic light scattering particle size distribution meter ("MICROTRACK UPA" manufactured by Nikkiso Co., Ltd.). Then, the particle diameter (D50) at 50% was determined.

The carbon dispersions 1 to 6, 20 to 27, 30, 31, and 49 to 52 were subjected to carbon wettability evaluation after the dispersion treatment. After the solvent of each carbon dispersion was distilled off under reduced pressure using an evaporator, the obtained residue was dried under reduced pressure at 80 ° C. for 10 hours. Subsequently, the dried product was pulverized with an agate mortar and further dried under reduced pressure at 80 ° C. for 12 hours. The obtained dried product was pulverized again with an agate mortar and then loaded with 500 kgf / cm ² with a tablet molding machine (Specac) to produce carbon pellets (diameter 10 mm, thickness 0.5 mm). A droplet in which ethylene carbonate and diethyl carbonate were mixed 1: 1 was dropped on this pellet with a microsyringe, and the time for the droplet to penetrate the pellet was measured. This measurement was performed 5 times for each sample, and those whose average permeation time was less than 1 second was “◎”, those that were 1 second or more and less than 5 seconds were “◯”, and those that were 5 seconds or more and less than 10 seconds. What was there was “Δ”, and what was 10 seconds or longer was “x”.

The carbon material dispersions (dispersions 1 to 50, 57) using the dispersants Aa to As and the dispersants Ba to Bo may be used in the case where no dispersant is used (dispersions 51 to 53) or general surfactants. It can be seen that the dispersibility is good, the viscosity is low, and the dispersion particle size is small as compared with the case of using (dispersion 54, 55). Furthermore, dispersions 1 to 50 and 57 also had good temporal dispersion stability (50 ° C. × 3 days), and neither thickening nor aggregation was observed. Moreover, in the dispersion using the dispersant of the present invention, the wettability of the carbon to the electrolytic solution was improved as compared with the case where the dispersant was not used. In particular, when the dispersant has an acidic functional group and an ammonium salt type, the effect of improving wettability is great.
<Preparation of battery electrode composite material>
[Composite materials A1 to A42]
According to the composition shown in Tables 12 and 13, any two parts of carbon dispersions 1 to 25 and 30 to 46 were added to 48 parts of NMP to obtain a diluted carbon material dispersion. 50 parts of spinel lithium manganate LiMn ₂ O ₄ (cell seed S-LM, primary particle diameter 0.6 μm, specific surface area 1.8 m ² / g, manufactured by Nippon Chemical Industry Co., Ltd.) is added to the dispersion as a positive electrode active material. Then, a three-pass mixing process was performed at a pressure of 100 MPa using a wet jet mill (Genus PY, manufactured by Genus) to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials A1 to A42. The mass ratio of LiMn ₂ O ₄ and the carbon material adsorbed with the dispersant was 100: 0.4.
[Composite materials B1, B2]
According to the composition shown in Table 13, 1 part of carbon dispersion 5 or 30 was added to 99 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 100 parts of lithium cobalt oxide LiCoO ₂ (HLC-17, primary particle size 9.3 μm, specific surface area 0.54 m ² / g, manufactured by Honjo Chemical Co., Ltd.) was added as a positive electrode active material. And mixing was performed to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials B1 and B2. The mass ratio of LiCoO ₂ to the carbon material adsorbed with the dispersant was 100: 0.1.
[Composite materials C1 to C8]
According to the composition shown in Table 13, 5 parts of carbon dispersions 26 to 29 and 47 to 50 were added to 45 parts of various solvents to obtain diluted carbon material dispersions. While stirring the dispersion with a homogenizer, 50 parts of lithium iron phosphate LiFePO ₄ (primary particle size 3.6 μm, specific surface area 15 m ² / g, manufactured by Tianjin Styl Energy Technology) was added as a positive electrode active material, and mixing was performed. And a composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials C1 to C8. The mass ratio between LiFePO ₄ and the carbon material adsorbed with the dispersant was 100: 1.
[Composite materials D1, D2]
First, 1.962 mol of lithium hydroxide (LiOH.H ₂ O) was added to 451 g of water and dissolved by stirring. 2.453 mol of 98% pure anatase-type titanium oxide as TiO ₂ was added to the solution and stirred. At this time, the atomic ratio of Li and Ti is 4: 5. The volume of the mixed slurry is 0.502 L, and the slurry concentrations of the Li raw material and the Ti raw material before drying are 3.91 mol / L and 4.89 mol / L, respectively. After the mixture was spray-dried at 110 ° C., the dried product was heat-treated at 780 ° C. for 10 hours in an oxygen gas stream to produce lithium titanate.

Next, according to the composition shown in Table 13, 5 parts of carbon dispersion 5 or 30 was added to 45 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 50 parts of the above lithium titanate Li ₄ Ti ₅ O ₁₂ (primary particle diameter 0.3 μm, specific surface area 15 m ² / g) was added as a negative electrode active material, and mixed. A composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials D1 and D2. The mass ratio between Li ₄ Ti ₅ O ₁₂ and the carbon material adsorbed with the dispersant was 100: 1.

[Composite materials E1, E2]
According to the composition shown in Table 13, 1 part of carbon dispersion 27 or 48 was added to 99 parts of purified water to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 100 parts of mesophase carbon MFC (MCMB6-28, primary particle size 6 μm, specific surface area 4 m ² / g, manufactured by Osaka Gas Chemical Co., Ltd.) as a negative electrode active material was added and mixed. A composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials E1 and E2. The mass ratio of MFC to the carbon material adsorbed with the dispersant was 100: 1.
[Composite materials a1 to a5]
According to the composition shown in Table 14, 48 parts of NMP was added to 2 parts of carbon dispersion 51 or 52 to obtain a diluted carbon material dispersion. 50 parts of spinel lithium manganate LiMn ₂ O ₄ (cell seed S-LM, primary particle diameter 0.6 μm, specific surface area 1.8 m ² / g, manufactured by Nippon Chemical Industry Co., Ltd.) is added to the dispersion as a positive electrode active material. Then, a three-pass mixing process was performed at a pressure of 100 MPa using a wet jet mill (Genus PY, manufactured by Genus) to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials a1 and a2. The mass ratio between LiMn ₂ O ₄ and the carbon material was 100: 0.4.

Moreover, according to the composition shown in Table 14, NMP was added to 45 parts of any 2 parts of carbon dispersions 54 to 56 to obtain a diluted carbon material dispersion. 50 parts of spinel lithium manganate LiMn ₂ O ₄ (cell seed S-LM, primary particle diameter 0.6 μm, specific surface area 1.8 m ² / g, manufactured by Nippon Chemical Industry Co., Ltd.) is added to the dispersion as a positive electrode active material. Then, a three-pass mixing process was performed at a pressure of 100 MPa using a wet jet mill (Genus PY, manufactured by Genus) to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials a3 to a5. The mass ratio of LiMn ₂ O ₄ and the carbon material adsorbed with the dispersant was 100: 0.4.
[Composite materials b1 to b4]
According to the composition shown in Table 14, 1 part of carbon dispersion 52 was added to 99 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 100 parts of lithium cobalt oxide LiCoO ₂ (HLC-17, primary particle size 9.3 μm, specific surface area 0.54 m ² / g, manufactured by Honjo Chemical Co., Ltd.) was added as a positive electrode active material. And mixing was performed to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain a composite material b1. The mass ratio between LiCoO ₂ and the carbon material was 100: 0.1.
Further, according to the composition shown in Table 14, one part of carbon dispersions 54 to 56 was added to 99 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 100 parts of lithium cobalt oxide LiCoO ₂ (HLC-17, primary particle size 9.3 μm, specific surface area 0.54 m ² / g, manufactured by Honjo Chemical Co., Ltd.) was added as a positive electrode active material. And mixing was performed to obtain a composite material slurry. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials b2 to b4. The mass ratio of LiCoO ₂ to the carbon material adsorbed with the dispersant was 100: 0.1.
[Composite material c1]
According to the composition shown in Table 14, 45 parts of purified water and 5 parts of carbon dispersion 53 were added to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 50 parts of lithium iron phosphate LiFePO ₄ (primary particle size 3.6 μm, specific surface area 15 m ² / g, manufactured by Tianjin Styl Energy Technology) was added as a positive electrode active material, and mixing was performed. And a composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain a composite material c1. The mass ratio between LiFePO ₄ and the carbon material was 100: 1.
[Composite materials d1 to d4]
First, 1.962 mol of lithium hydroxide (LiOH.H ₂ O) was added to 451 g of water and dissolved by stirring. 2.453 mol of 98% pure anatase-type titanium oxide as TiO ₂ was added to the solution and stirred. At this time, the atomic ratio of Li and Ti is 4: 5. The volume of the mixed slurry is 0.502 L, and the slurry concentrations of the Li raw material and the Ti raw material before drying are 3.91 mol / L and 4.89 mol / L, respectively. After the mixture was spray-dried at 110 ° C., the dried product was heat-treated at 780 ° C. for 10 hours in an oxygen gas stream to produce lithium titanate.

Next, according to the composition shown in Table 14, 5 parts of carbon dispersion 52 was added to 45 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 50 parts of the above lithium titanate Li ₄ Ti ₅ O ₁₂ (primary particle diameter 0.3 μm, specific surface area 15 m ² / g) was added as a negative electrode active material, and mixed. A composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain a composite material d1. The mass ratio between Li ₄ Ti ₅ O ₁₂ and the carbon material was 100: 1.

Moreover, according to the composition shown in Table 14, 5 parts of any of carbon dispersions 54 to 56 were added to 45 parts of NMP to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 50 parts of the above lithium titanate Li ₄ Ti ₅ O ₁₂ (primary particle diameter 0.3 μm, specific surface area 15 m ² / g) was added as a negative electrode active material, and mixed. A composite slurry was obtained. The slurry was dried, crushed, and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain composite materials d2 to d4. The mass ratio between Li ₄ Ti ₅ O ₁₂ and the carbon material adsorbed with the dispersant was 100: 1.

[Composite material e1]
According to the composition shown in Table 14, 1 part of carbon dispersion 53 was added to 99 parts of purified water to obtain a diluted carbon material dispersion. While stirring the dispersion with a homogenizer, 100 parts of mesophase carbon MFC (MCMB6-28, primary particle size 6 μm, specific surface area 4 m ² / g, manufactured by Osaka Gas Chemical Co., Ltd.) as a negative electrode active material was added and mixed. A composite slurry was obtained. The slurry was dried, crushed and classified using a spray dryer (SD-100, manufactured by Tokyo Riken Kikai Co., Ltd.) to obtain a composite material e1. The mass ratio of MFC to carbon material was 100: 0.1.

<Preparation of positive electrode mixture paste for lithium ion secondary battery>
[Examples 1-44, Comparative Examples 1-5, 9-12]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. 92 parts of various active material composite materials, 3 parts of HS-100, and 45 parts of the binder solution were charged into a planetary mixer, and mixed for 1 hour. Further, after 5 parts of N-methyl-2-pyrrolidone was added for dilution, the mixture was subsequently mixed in a planetary mixer for 30 minutes to prepare a positive electrode mixture paste. The active material composite materials used in the examples and comparative examples are shown in Tables 15 and 16.
[Comparative Example 6]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. 90 parts of the active material composite material a2, 5 parts of HS-100, and 45 parts of the binder solution were put into a planetary mixer and mixed for 1 hour. Further, after 5 parts of N-methyl-2-pyrrolidone was added for dilution, the mixture was subsequently mixed in a planetary mixer for 30 minutes to prepare a positive electrode mixture paste.
[Comparative Example 7]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. As a positive electrode active material, 92 parts of lithium spinel manganate LiMn ₂ O ₄ (cell seed S-LM, primary particle diameter 0.6 μm, specific surface area 1.8 m ² / g, manufactured by Nippon Chemical Industry Co., Ltd.), 3 HS-100 And 45 parts of the binder solution were charged into a planetary mixer and mixed for 1 hour. Further, after 5 parts of N-methyl-2-pyrrolidone was added for dilution, the mixture was subsequently mixed in a planetary mixer for 30 minutes to prepare a positive electrode mixture paste.
[Comparative Example 8]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. As a positive electrode active material, 90 parts of lithium spinel manganate LiMn ₂ O ₄ (cell seed S-LM, primary particle size 0.6 μm, specific surface area 1.8 m ² / g, manufactured by Nippon Chemical Industry Co., Ltd.), 5 HS-100 And 45 parts of the binder solution were charged into a planetary mixer and mixed for 1 hour. Further, after 5 parts of N-methyl-2-pyrrolidone was added for dilution, the mixture was subsequently mixed in a planetary mixer for 30 minutes to prepare a positive electrode mixture paste.
[Examples 45 to 52, Comparative Example 13]
As a binder, 1 part of CMC and 4 parts of SBR were dissolved in 40 parts of purified water to prepare 45 parts of a binder solution. 93 parts of various active material composite materials, 2 parts of HS-100, and 45 parts of the binder solution were put into a planetary mixer, and mixed for 1 hour. Furthermore, after adding 5 parts of purified water and diluting, the mixture process was continued for 30 minutes with the planetary mixer, and the positive mix paste was prepared. Table 17 shows the active material composite materials used in the examples and comparative examples.
[Comparative Example 14]
As a binder, 1 part of CMC and 4 parts of SBR were dissolved in 40 parts of purified water to prepare 45 parts of a binder solution. As a positive electrode active material, lithium iron phosphate LiFePO ₄ (primary particle diameter 3.6 μm, specific surface area 15 m ² / g, manufactured by Tianjin Stl Energy Technology) 92 parts, HS-100 3 parts, and binder solution 45 parts planetar The mixture was put into a Lee mixer and mixed for 1 hour. Furthermore, after adding 5 parts of purified water and diluting, the mixture process was continued for 30 minutes with the planetary mixer, and the positive mix paste was prepared.
[Comparative Example 15]
As a binder, 1 part of CMC and 4 parts of SBR were dissolved in 40 parts of purified water to prepare 45 parts of a binder solution. As positive electrode active material, lithium iron phosphate LiFePO ₄ (primary particle size 3.6 μm, specific surface area 15 m ² / g, manufactured by Tianjin Stl Energy Technology) 90 parts, HS-100 5 parts, and binder solution 45 parts planetar The mixture was put into a Lee mixer and mixed for 1 hour. Furthermore, after adding 5 parts of purified water and diluting, the mixture process was continued for 30 minutes with the planetary mixer, and the positive mix paste was prepared.

<Preparation of negative electrode mixture paste for lithium ion secondary battery>
[Examples 53 and 54, Comparative Examples 16 to 19]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. 93 parts of various active material composite materials, 2 parts of HS-100, and 45 parts of the binder solution were put into a planetary mixer, and mixed for 1 hour. Furthermore, after diluting by adding 5 parts of N-methyl-2-pyrrolidone, the mixture treatment was continued for 30 minutes with a planetary mixer to prepare a negative electrode mixture paste. Table 17 shows the active material composite materials used in the examples and comparative examples.
[Comparative Example 20]
As a binder, 5 parts of PVDF was dissolved in 40 parts of NMP to prepare 45 parts of a binder solution. As a negative electrode active material, 92 parts of lithium titanate prepared by the same method as that prepared for preparing the composite material C1, 3 parts of HS-100, and 45 parts of a binder solution were charged into a planetary mixer. Time mixing was performed. Furthermore, after diluting by adding 5 parts of N-methyl-2-pyrrolidone, the mixture treatment was continued for 30 minutes with a planetary mixer to prepare a negative electrode mixture paste.
[Examples 55 and 56, Comparative Example 21]
As a binder, 1 part of CMC and 4 parts of SBR were dissolved in 40 parts of purified water to prepare 45 parts of a binder solution. 92 parts of various active material composite materials, 3 parts of HS-100, and 45 parts of the binder solution were charged into a planetary mixer, and mixed for 1 hour. Further, after 5 parts of purified water was added for dilution, the mixture was subsequently mixed for 30 minutes with a planetary mixer to prepare a negative electrode mixture paste. Table 17 shows the active material composite materials used in the examples and comparative examples.
[Comparative Example 22]
As a binder, 1 part of CMC and 4 parts of SBR were dissolved in 40 parts of purified water to prepare 45 parts of a binder solution. 92 parts of mesophase carbon MFC (MCMB6-28, primary particle diameter 6 μm, specific surface area 4 m ² / g, manufactured by Osaka Gas Chemical Company), 3 parts of HS-100, and 45 parts of a binder solution as a negative electrode active material planetary mixer And mixed for 1 hour. Further, after 5 parts of purified water was added for dilution, the mixture was subsequently mixed in a planetary mixer for 30 minutes to prepare an electrode mixture paste.

<Preparation of positive electrode for lithium ion secondary battery>
[Examples 1 to 52, Comparative Examples 1 to 15]
The various positive electrode mixture pastes prepared above were applied onto a 20 μm thick aluminum foil serving as a current collector using a doctor blade, then heated and dried at 120 ° C. under reduced pressure, and then rolled with a roller press. Then, a positive electrode mixture layer having a thickness of 60 μm was produced.
<Preparation of negative electrode for lithium ion secondary battery>
[Examples 53 to 56, Comparative Examples 16 to 22]
The various negative electrode mixture pastes prepared above were applied onto a copper foil having a thickness of 20 μm to be a current collector using a doctor blade, dried by heating at 120 ° C. under reduced pressure, and then rolled with a roller press. Then, a negative electrode mixture layer having a thickness of 60 μm was produced.
<Assembly of lithium ion secondary battery positive electrode evaluation cell>
[Examples 1 to 52, Comparative Examples 1 to 15]
A separator made of a porous polypropylene film between the working electrode and the counter electrode (# 2400, manufactured by Celgard Co., Ltd.) with the positive electrode produced previously punched into a diameter of 9 mm and used as a working electrode, and a metallic lithium foil (thickness 0.15 mm) as a counter electrode Is inserted and laminated, filled with an electrolyte (nonaqueous electrolyte in which LiPF ₆ is dissolved at a concentration of 1M in a mixed solvent of ethylene carbonate and diethyl carbonate in a ratio of 1: 1), and a bipolar metal cell (Hosen) (HS flat cell). The cell was assembled in a glove box substituted with argon gas, and a predetermined battery characteristic evaluation was performed after the cell was assembled.
<Assembly of lithium ion secondary battery negative electrode evaluation cell>
[Examples 53 to 56, Comparative Examples 16 to 22]
A separator made of a porous polypropylene film between the working electrode and the counter electrode (# 2400, manufactured by Celgard Co., Ltd.) with the negative electrode prepared previously punched to a diameter of 9 mm and used as a working electrode, and a metallic lithium foil (thickness 0.15 mm) as a counter electrode Is inserted and laminated, filled with an electrolyte (nonaqueous electrolyte in which LiPF ₆ is dissolved at a concentration of 1M in a mixed solvent of ethylene carbonate and diethyl carbonate in a ratio of 1: 1), and a bipolar metal cell (Hosen) (HS flat cell). The cell was assembled in a glove box substituted with argon gas, and a predetermined battery characteristic evaluation was performed after the cell was assembled.
<Characteristic evaluation of lithium ion secondary battery positive electrode>
[Examples 1 to 52, Comparative Examples 1 to 15]
The produced battery evaluation cell was fully charged at a constant current and constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C.) with a charge rate of 0.2 C and 1.0 C, and at a constant current at the same rate as during charging. Charge / discharge for discharging to a discharge lower limit voltage of 3.0V is defined as one cycle (charge / discharge interval rest time 30 minutes), and this cycle is performed for a total of 20 cycles to evaluate charge / discharge cycle characteristics (Evaluation apparatus: SM-8 manufactured by Hokuto Denko Co., Ltd.) ) Moreover, the cell after evaluation was decomposed | disassembled, the external appearance of the electrode coating film was confirmed visually, and it was set as x when it was confirmed that the composite material has partially peeled from the electrical power collector. The evaluation results are shown in Tables 18-20.

  From Table 18 to Table 20, Examples 1-42 using the composite material in the present invention are Comparative Examples 1 and 2 in which a composite material was prepared without using a dispersant, and Comparative Examples 3 and 4 in which a surfactant was used. In comparison with Comparative Example 5 using a dispersion resin and Comparative Example 7 in which a composite paste was prepared without using a composite material, good results were obtained in both battery capacity and 20 cycle capacity retention rate. In Comparative Examples other than Comparative Example 5 using a dispersion resin, the composite material was peeled off from the current collector after evaluation. In addition, Comparative Examples 7 and 9 in which the amount of the conductive auxiliary agent was increased slightly improved the cycle characteristics, but the battery capacity was reduced, whereas Examples 1-42 were cycle characteristics without impairing the battery capacity. It can be said that the effect of reducing the amount of the conductive auxiliary agent by using the composite material of the present invention was exhibited.

  Similarly, from Table 20, both Examples 43 and 44 have better results in battery capacity and 20 cycle capacity retention ratio than Comparative Examples 9 to 12, and the composite material of the present invention has various positive electrode actives. It was shown to be applicable to the substance.

  From Table 20, Examples 45-52 made into a mixture paste in an aqueous system have battery capacities as compared with Comparative Examples 13-15 that do not use a derivative having an acidic functional group and a derivative having a basic functional group. Good results were obtained at a 20 cycle capacity retention rate. If attention was paid to the reactivity with the active material, it was confirmed that various solvents can be used in the production of the composite material. Moreover, it was confirmed that arbitrary combinations can be used for the positive electrode active material, the solvent, and the binder.

Moreover, about Example 5 using the derivative Aa which has an acidic functional group as a dispersing agent, and the comparative example 2 which did not use a dispersing agent, the part which was not used for battery evaluation of the positive electrode produced previously is a scanning type. When the surface was observed with an electron microscope (S-3400S manufactured by Hitachi, Ltd.), in Example 5, the active material particles were satisfactorily coated with the carbon material, whereas in Comparative Example 2, the aggregation of the carbon material was remarkable. Many portions where the active material surface was exposed were also observed.
<Evaluation of lithium ion secondary battery negative electrode characteristics>
[Examples 53 to 56, Comparative Examples 16 to 22]
The battery evaluation cell thus prepared was fully charged at a constant current and constant voltage charge (upper limit voltage 0.5 V) at room temperature (25 ° C.), with a charge rate of 0.2 C and 1.0 C, and a voltage at a constant current at the same rate as during charging. Charging / discharging until 1 V reaches 1.5 V is defined as one cycle (charging / discharging interval pause time 30 minutes), and this cycle is performed for a total of 20 cycles, and charging / discharging cycle characteristics evaluation (evaluation apparatus: SM-8 manufactured by Hokuto Denko) Went. Moreover, the cell after evaluation was decomposed | disassembled, the presence or absence of the electrode coating film defect was confirmed visually, and it was set as x when it was confirmed that the composite material has partially peeled from the electrical power collector. The evaluation results are shown in Table 21.

  From Table 21, Examples 53 and 54 are both battery capacity and 20 cycle capacity maintenance ratio compared with Comparative Examples 16-20 which does not use the derivative which has an acidic functional group, and the derivative which has a basic functional group. Good results were obtained. Therefore, it was confirmed that the composite material of the present invention can also be applied to the negative electrode.

  Similarly, in Examples 55 and 56, as compared with Comparative Examples 21 and 22, good results were obtained in both battery capacity and 20 cycle capacity maintenance rate. It was shown that any combination of negative electrode active material, solvent, and binder can be used.

  Moreover, about Example 55 using the derivative Aa which has an acidic functional group as a dispersing agent, and the comparative example 21 which did not use a dispersing agent, the part which was not used for battery evaluation of the negative electrode produced previously is a scanning type. When the surface was observed with an electron microscope (S-3400S, manufactured by Hitachi, Ltd.), as in the case of the positive electrode, in Example 55, the active material particles were satisfactorily covered with the carbon material, whereas Comparative Example 21 was used. Was in a state of insufficient coating.

Claims (12)

At least one carbon material, an organic dye derivative having an acidic functional group, a triazine derivative having an acidic functional group, an organic dye derivative having a basic functional group, and a basic functional group as a dispersant for the carbon material. A method for producing a battery electrode composite material, wherein the surface of an electrode active material is coated with one or more derivatives selected from the group consisting of triazine derivatives. 2. The battery electrode composite material according to claim 1, wherein the solvent is removed after mixing a dispersion in which at least one carbon material is dispersed in a solvent using a dispersant and the electrode active material. Manufacturing method. The method for producing a battery electrode composite material according to claim 2, wherein the dispersion contains a derivative having an acidic functional group and a base having a molecular weight of 500 or less as a dispersion aid. The method for producing a composite material for battery electrodes according to claim 2, wherein the dispersion contains a derivative having a basic functional group and an acid having a molecular weight of 300 or less as a dispersion aid. 5. The method for producing a battery electrode composite material according to claim 3, wherein the dispersion aid is removed together with the solvent. The method for producing a composite material for a battery electrode according to any one of claims 2 to 5, wherein the dispersed particle diameter (D50) of the carbon material in the dispersion is 2 µm or less. The composite material for battery electrodes manufactured with the manufacturing method in any one of Claims 1-5. The composite material for battery electrodes according to claim 7, wherein the primary particle diameter of the carbon material is 10 to 100 nm. An electrode mixture paste comprising the battery electrode composite material according to claim 7 or 8, a solvent, and a binder component. The electrode mixture paste according to claim 9, further comprising a conductive auxiliary component. An electrode mixture layer is formed on the current collector using the battery electrode composite material according to claim 7 or 8, or the electrode mixture paste according to claim 9 or 10. Battery electrode. A lithium ion secondary battery comprising a positive electrode having a positive electrode mixture layer on a current collector, a negative electrode having a negative electrode mixture layer on the current collector, and an electrolyte containing lithium, wherein the positive electrode and the negative electrode are at least One side is the battery electrode of Claim 11, The lithium ion secondary battery characterized by the above-mentioned.