KR20160013867A - Binder for use in electrochemical device electrodes, particle composite for use in electrochemical device electrodes, electrochemical device electrode, electrochemical device, and electrochemical device electrode manufacturing method - Google Patents

Abstract

It is an object of the present invention to provide a method for producing a polymer electrolyte membrane which is excellent in productivity of electrodes and does not require a water-soluble polymer component as a dispersant because slurry is not produced at the time of forming an electrode layer, A binder for electrodes, an electrode, an electrochemical device, and a method for producing an electrochemical device. The present invention relates to a powdery composite particle comprising a polymer having a glass transition temperature of 35 to 80 DEG C and a D50 average particle diameter based on the volume of primary particles of 80 to 1000 nm, a volatile content at 120 DEG C of less than 1 wt% , And relates to a binder for an electrochemical device electrode which is a powdery composite particle.

Description

TECHNICAL FIELD [0001] The present invention relates to a binder for an electrochemical device electrode, a particle composite for an electrochemical device electrode, an electrochemical device electrode, an electrochemical device, and a method for manufacturing an electrochemical device electrode. DEVICE ELECTRODE, ELECTROCHEMICAL DEVICE, AND ELECTROCHEMICAL DEVICE ELECTRODE MANUFACTURING METHOD}

The present invention relates to a binder for an electrochemical device electrode, a particle composite for an electrochemical device electrode, an electrochemical device electrode, an electrochemical device, and a method for producing an electrochemical device electrode.

BACKGROUND ART Electrochemical devices such as a lithium ion secondary battery, an electric double layer capacitor, and a lithium ion capacitor are rapidly expanding in popularity because of their small size, light weight, high energy density, and repeated charge / discharge characteristics. Lithium ion secondary batteries are used in mobile fields such as portable telephones and notebook personal computers because of their relatively large energy density. On the other hand, since the electric double layer capacitor can be rapidly charged and discharged, it is used as a memory backup small power source for a personal computer or the like, and the electric double layer capacitor is expected to be used as an auxiliary power source for electric vehicles and the like. In addition, lithium ion capacitors utilizing the advantages of lithium ion secondary batteries and electric double layer capacitors have higher energy density and higher output density than electric double layer capacitors, and are used for electric double layer capacitors and for electric double layer capacitors. The application to a use that can not be satisfied is being examined. Of these, lithium ion secondary batteries have recently been studied not only for use in automobiles such as hybrid electric vehicles and electric vehicles but also for power storage applications.

While the expectation for these electrochemical devices is high, there is a demand for further improvement in these electrochemical devices, such as lowering the resistance, increasing the capacity, improving the mechanical characteristics and the productivity, as the applications are expanded and developed. In such a situation, a manufacturing method with higher productivity is required for the electrode for an electrochemical device.

An electrode for an electrochemical device is generally formed by laminating an electrode active material layer and an electrode active material layer formed by binding a conductive agent, which is used if necessary, with a binder on a current collector. In the electrode for electrochemical device, there is an applied electrode manufactured by applying a slurry for a coating electrode containing an electrode active material, a binder, a conductive agent, and the like onto a current collector and removing the solvent by heat or the like. For example, in Patent Document 1, a polymer particle obtained by extruding and pulverizing a polymer is used as a binder, and the binder, the electrode active material, the conductive agent, and the solvent are mixed to obtain a slurry for a coated electrode, To obtain a coated electrode. Further, the polymer particles used in Patent Document 1 are dried binders, that is, dry binders.

However, in these methods, energy for removing the solvent from the slurry for drying or applied electrodes for the polymer film is required, which increases the cost and makes it difficult to improve the productivity.

Thus, a method of manufacturing an electrode without using a slurry for a coating electrode has been proposed. For example, in Patent Document 2, an electrode active material layer is formed by using a powdery mixture obtained by mixing a dry binder or a binder dispersed in a solvent, an electrode active material, and a conductive material containing a carbon material and drying the mixture. In Patent Document 3, a coating film is formed on the surface of the negative electrode of a lithium primary battery by mixing a carbon powder and a binder in a wet manner and then drying and pulverizing the mixed powder.

There has also been proposed a method of not only using a slurry for a coating electrode but also obtaining an electrode material without dispersing the binder in a solvent to form an electrode active material layer. For example, in Patent Document 4, an electrode active material layer is formed by using a mixed powder obtained by mixing a binder particle and a electrode active material mixed with a conductive agent by a suspension polymerization method performed in the presence of a conductive agent.

In Patent Document 5, a mixed powder obtained by mixing an electrode active material, a binder and a conductive agent is used as a binder by using polyvinylidene fluoride (PVDF) powder which is a dry binder and is attached to the surface of the collector by electrostatic coating, And then these components are fused at a temperature equal to or higher than the softening point of the binder to form the electrode active material layer on the current collector.

International Publication No. 2007/122947 Japanese Patent 4687458 Japanese Laid-Open Patent Publication No. 2010-86738 Japanese Laid-Open Patent Publication No. 2011-14409 Japanese Patent Application Laid-Open No. 2001-351616

However, when the electrode active material layer is formed using an electrode material obtained by dry-blending a dry binder and an electrode active material using a dry binder as a binder, if the binder described in Patent Document 1 is used, the glass transition temperature Is too high, an electrode having sufficient flexibility can not be obtained. In addition, when the binder described in Patent Document 2 or 5 is used, since the glass transition temperature of the binder is too low, it is difficult to form a uniform electrode active material layer. Patent Documents 3 and 4 do not disclose the use of dry binders.

Further, when the binder used in Patent Document 5 is used, since the particle diameter of the binder is large, there are few binding points connecting the electrode active materials, and it has been difficult to obtain an electrode having sufficient strength.

It is an object of the present invention to provide a polymer electrolyte membrane which is excellent in productivity of electrodes and does not require a water-soluble polymer component as a dispersant because slurry is not produced at the time of forming an electrode layer, A binder for an electrochemical device electrode, an electrochemical device electrode particle composite using the binder for the electrochemical device electrode, and an electrochemical device electrode and an electrochemical device using the electrochemical device electrode particle composite. It is another object of the present invention to provide a method for producing an electrochemical device electrode which is excellent in productivity and has excellent thickness precision and flexibility.

As a result of intensive studies for solving the above problems, the present inventors have found that the above objects can be achieved by setting the glass transition temperature and the average particle diameter to a predetermined range, and have completed the present invention.

That is, according to the present invention,

(1) A positive electrode active material composition comprising (1) a polymer having a glass transition temperature of 35 to 80 DEG C and a D50 average particle diameter based on the volume of primary particles of 80 to 1000 nm, a volatile content at 120 DEG C of less than 1% A binder for an electrochemical device electrode,

(2) The binder for an electrochemical device electrode according to (1), which is obtained by drying an aqueous dispersion of a particulate polymer in which the polymer is dispersed at a temperature lower than the lowest film forming temperature of the particulate polymer,

(3) a conjugated diene monomer unit, an acrylate ester monomer unit, a methacrylate ester monomer unit, an aromatic vinyl compound monomer unit, an ethylenically unsaturated nitrile monomer unit, an ethylenically unsaturated carboxylic acid monomer unit, an ethylenically unsaturated amide monomer unit, (1) or (2), wherein the binder contains at least one monomer unit selected from the group consisting of an alkylene oxide monomer and a functional ethylene monomer unit,

(4) An electrochemical device electrode particle composite obtained by dry-blending an electrode active material with the binder for an electrochemical device electrode according to any one of (1) to (3)

(5) The electrochemical device electrode particle composite according to (4), wherein the ratio (Da / Db) of the D50 average particle diameter (Da) based on the volume of the electrochemical device electrode particle composite to the D50 average particle diameter A particle composite for an electrochemical device electrode,

(6) An electrochemical device electrode comprising an electrode active material layer comprising the particle composite for an electrochemical device electrode according to (5), laminated on the current collector,

(7) The electrochemical device electrode according to (6), wherein the electrode active material layer is obtained by press-molding an electrode material containing the electrochemical device electrode particle composite onto the current collector,

(8) An electrochemical device comprising the electrochemical device electrode according to (6) or (7)

(9) An aqueous dispersion in which a particulate polymer having a glass transition temperature of 35 to 80 캜 and a spherical shape having a D50 average particle size of 80 to 1000 nm on the basis of the volume of primary particles is dispersed is dried at a temperature lower than the lowest film forming temperature of the particulate polymer, A mixing step of mixing the powdery composite particles with an electrode active material to obtain a particle composite; and an electrode manufacturing step of producing an electrode using the particle composite, A method of manufacturing an element electrode is provided.

 INDUSTRIAL APPLICABILITY According to the present invention, since the slurry is not produced at the time of forming the electrode layer, the productivity of the electrode is excellent, the water-soluble polymer is not required as a dispersant, A binder for a chemical device electrode, an electrochemical device electrode particle composite using the electrochemical device electrode binder, an electrochemical device electrode using the electrochemical device electrode particle composite, and an electrochemical device. Further, according to the present invention, it is possible to provide a method for producing an electrochemical device electrode that is excellent in productivity, and has excellent thickness precision and flexibility.

Hereinafter, the binder for an electrochemical device electrode of the present invention will be described. The binder for electrochemical device electrode of the present invention (hereinafter sometimes referred to as " binder for electrode ") has a glass transition temperature of 35 to 80 캜, a D50 average particle diameter based on the volume of primary particles of 80 to 1000 nm , And the volatile matter at 120 캜 is less than 1% by weight, and is a powdery composite particle.

In the present specification, the "positive electrode active material" means an electrode active material for a positive electrode, and the "negative electrode active material" means an electrode active material for a negative electrode. The "positive electrode active material layer" means an electrode active material layer formed on the positive electrode, and the "negative electrode active material layer" means an electrode active material layer formed on the negative electrode.

(Binder for electrochemical device electrode)

The glass transition temperature (Tg) of the binder for electrodes of the present invention is 35 to 80 캜, preferably 40 to 75 캜, more preferably 40 to 70 캜, still more preferably 40 to 60 캜, 45 to 55 ° C. When the glass transition temperature of the electrode binder is within this range, a flexible and sufficiently strong electrode can be obtained. If the glass transition temperature of the electrode binder is too high, it becomes difficult to obtain an electrode having sufficient flexibility. If the glass transition temperature of the binder for the electrode is too low, the fluidity of the particle composite described later is not sufficient, and the thickness precision of the resulting electrode is deteriorated. That is, thickness irregularities occur in the electrodes.

The D50 average particle diameter (hereinafter referred to as " primary particle diameter ") of the primary particles of the electrode binder of the present invention based on the volume is preferably 80 to 1000 nm, more preferably 80 to 800 nm, 100 to 500 nm, and more preferably 130 to 400 nm. When the primary particle diameter of the electrode binder is within this range, the bonding strength between the current collector and the electrode active material can be sufficiently maintained. If the primary particle size of the binder for the electrode is too large, the adhesiveness is deteriorated, so that when the flexibility test of the electrode described below is carried out, the powder falls off. If the primary particle size of the binder for the electrode is too small, the binder for the electrode is not well dispersed, resulting in poor adhesion.

The binder for electrodes can be obtained by drying the aqueous dispersion of the particulate polymer obtained by the polymerization method as described later. The primary particle size of the particulate polymer in this aqueous dispersion is in the range described above. The shape of the particulate polymer is preferably spherical.

(1 - (Ll - Ls) / La) x 100 is defined as a sphericity (%), and the value of (1 - , The sphericity is 80% or more.

Here, the short axis Ls and the long axis Ll are the long axis Ll and the short axis Ls of a predetermined number of polymer particles, for example, 10 to 30 as measured by observing photographic images of the transmission type or scanning electron microscope, Respectively. Further, La is a value that can be obtained by calculating La = (Ls + L1) / 2.

The volatile content of the electrode binder of the present invention at 120 캜 is less than 1% by weight. When the volatile content of the electrode binder at this temperature is within this range, the binder for the electrode is uniformly dispersed and an electrode having sufficient strength can be obtained. In addition, since the fluidity of the particle composite described later is improved, an electrode having good thickness accuracy can be obtained. If the volatile content of the electrode binder at 120 캜 is too large, an electrode having sufficient strength can not be obtained because the binder for electrodes is not dispersed at the time of producing the particle composite, and the fluidity of the particle composite is not sufficient As a result, the thickness precision of the obtained electrode is deteriorated.

The binder for electrodes of the present invention is present as a spherical shape or a powdery form (aggregate of spheres) in which a plurality of spheres are combined, that is, as powdery composite particles. The primary particles of the electrode binder may be present as individual particles, but usually, a plurality of primary particles form one particle by bonding with an intermolecular force while maintaining the shape thereof. In addition, the particles formed by the plurality of primary particles sometimes exist as individual particles individually due to external force. The shape of the binder for the electrode is a spherical shape or a shape in which a plurality of spheres are combined so that the fluidity of the particle composite can be ensured.

The binder for an electrode of the present invention is a binder for an electrode, which comprises a conjugated diene monomer unit, (meth) acrylic acid ester monomer unit, aromatic vinyl compound monomer unit, ethylenically unsaturated nitrile monomer unit, ethylenically unsaturated carboxylic acid monomer unit, ethylenically unsaturated amide monomer unit, And at least one monomer unit selected from polyfunctional ethylene monomer units. Further, in the present specification, "(meth) acryl" means "acrylic" and "methacryl".

Examples of the conjugated diene monomer constituting the conjugated diene monomer unit include conjugated dienes having 4 or more carbon atoms such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene have. Of these, 1,3-butadiene is preferred.

Examples of the (meth) acrylic acid ester monomers forming the (meth) acrylic acid ester monomer unit include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, Acrylic acid such as acrylic acid, methacrylic acid and the like, such as acrylic acid, methacrylic acid, maleic acid, maleic acid, maleic acid, Alkyl esters; And examples thereof include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, Methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, n-butyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, Esters and the like. Among them, the flexibility of the electrode is improved, peeling of the electrode can be suppressed when the winding cell is manufactured, and the characteristics (cycle characteristics, etc.) of the secondary battery using the electrode can be improved. Is preferably an acrylic acid alkyl ester or methacrylic acid alkyl ester having an alkyl group of 4 or more bonded thereto and an alkyl acrylate or methacrylic acid alkyl ester having 6 to 20 carbon atoms in an alkyl group bonded to a non- desirable.

Examples of the aromatic vinyl compound monomer forming the aromatic vinyl compound monomer unit include styrene,? -Methylstyrene, vinyltoluene, and the like.

The monomer forming the?,? - ethylenically unsaturated nitrile monomer unit is not limited as long as it is an?,? - ethylenically unsaturated compound having a nitrile group, and acrylonitrile; ? -halogenoacrylonitrile such as? -chloroacrylonitrile and? -bromoacrylonitrile; Alpha -alkyl acrylonitrile such as methacrylonitrile; , And acrylonitrile and methacrylonitrile are preferable. As the?,? - ethylenically unsaturated nitrile monomer, these plural species may be used in combination.

Examples of the ethylenically unsaturated carboxylic acid monomer forming the ethylenically unsaturated carboxylic acid monomer unit include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and the like.

Examples of the ethylenic unsaturated amide monomer forming the ethylenically unsaturated amide monomer unit include (meth) acrylamide, N-methylol (meth) acrylamide and N, N'-dimethylol (meth) acrylamide .

Examples of polyfunctional ethylenically unsaturated monomers having two or more olefinic double bonds forming a polyfunctional ethylenically unsaturated monomer unit include divinyl compounds such as divinylbenzene; Di (meth) acrylate esters such as ethylene di (meth) acrylate, diethylene glycol di (meth) acrylate and ethylene glycol di (meth) acrylate; Trimethylacrylic acid tri (meth) acrylate and trimethylolpropane tri (meth) acrylate; And the like.

There is no particular limitation on the method of polymerizing each monomer, but the emulsion polymerization method in which a latex of a particulate polymer (water dispersion) is obtained by using an emulsifying agent such as sodium dodecylbenzenesulfonate, or a method of using a dispersant such as polyvinyl alcohol A suspension polymerization method (including a micro suspension polymerization method) in which an aqueous dispersion of a particulate polymer is obtained, and the like can be preferably used. Of these, the emulsion polymerization method is more preferable because it is easy to control the polymerization reaction.

The binder for electrodes of the present invention can be obtained by drying a polymer obtained by polymerizing each monomer. That is, by drying the polymer, a binder for an electrode (powdery binder) which is a composite particle in the form of a powder can be obtained. The drying method is not particularly limited as long as the primary particles of the particulate polymer are not excessively adhered to each other and can be dried in a redispersible state. For example, a method of spray drying the aqueous dispersion of the particulate polymer, And the like. In addition, it is more preferable to dry in a vacuum condition after spray drying or a rotary evaporator.

The drying temperature is preferably lower than the lowest film-forming temperature of the particulate polymer, from the viewpoint that moisture can be removed in a re-dispersible state without excessively bonding the primary particles of the particulate polymer. When the drying temperature is too high, it becomes difficult to redisperse the particles because the particulate polymer becomes a film.

The minimum film-forming temperature of the particulate polymer is preferably 35 to 100 ° C, from the viewpoint that the particulate polymer can be dried in a redispersible state and the flowability of the particle composite to be described later and the flexibility of the electrode after formation of the electrode are both compatible . If the minimum film-forming temperature of the particulate polymer is too high, flexibility of the obtained electrode is lowered. If the minimum film-forming temperature of the particulate polymer is too low, it becomes difficult to dry the particulate polymer so that the primary particles do not excessively adhere. In other words, it becomes difficult to dry the particulate polymer in a re-dispersible state.

Here, the lowest film forming temperature is the lowest temperature at which the film of the particulate polymer is formed. The lowest film forming temperature can be measured in accordance with JIS K6828-2 (2003) or ISO 2115, for example. Specifically, an aqueous dispersion of a particulate polymer is applied and dried on a flat plate such as an iron plate having an appropriate temperature gradient to a thickness of about 100 mu m, and the boundary temperature between the filmed portion and the non-filmed portion is measured . Here, the filmed portion becomes transparent, and the portion that is not filmed becomes opaque, so that the boundary between the filmed portion and the non-filmed portion can be visually confirmed. In addition, when a flat plate after application and drying of an aqueous dispersion of particulate polymer is rubbed on a flat plate, the portion that is not filmed falls off, so that the boundary between the filmed portion and the non- Can be confirmed.

(Particle composite for electrochemical device electrode)

The particle composite for an electrochemical device electrode of the present invention (hereinafter sometimes referred to as a " particle composite ") comprises the above electrode binder and an electrode active material. The particle composite may contain a conductive agent if necessary. Here, in the particle composite, each of the electrode binder and the electrode active material may be present as separate particles, but usually, a binder for a plurality of electrodes is attached to the surface of the electrode active material to form one particle. A plurality of individual particles and one particle of the electrode binder and the electrode active material combine to form secondary particles while maintaining substantially the shape thereof. These secondary particles may be present as individual particles individually when subjected to an external force.

(Electrode active material)

The positive electrode active material in the case where the electrochemical device of the present invention is a lithium ion secondary battery is largely divided into an active material composed of an inorganic compound and an organic compound which can be doped and undoped with lithium ions.

Examples of the positive electrode active material composed of an inorganic compound include transition metal oxides, transition metal sulfides, and lithium-containing composite metal oxides of lithium and a transition metal. As the transition metal, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Mo are used.

Examples of transition metal oxides include MnO, MnO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , Cu ₂ V ₂ O ₃ , amorphous V ₂ OP ₂ O ₅ , MoO ₃ , V ₂ O ₅ , V ₆ O _13, etc. Among them, MnO, V ₂ O ₅ , V ₆ O ₁₃ and TiO ₂ are preferable from the viewpoint of cycle stability and capacity. Examples of the transition metal sulfide include TiS ₂ , TiS ₃ , amorphous MoS ₂ , and FeS. Examples of the lithium-containing composite metal oxide include a lithium-containing composite metal oxide having a layered structure, a lithium-containing composite metal oxide having a spinel structure, and a lithium-containing composite metal oxide having an olivine structure.

The lithium-containing composite metal oxide having a layered structure includes lithium-containing cobalt oxide (LiCoO ₂ ), lithium-containing nickel oxide (LiNiO ₂ ), lithium composite oxide of Co-Ni-Mn, lithium composite oxide of Ni- And a lithium complex oxide of -Co-Al. A lithium-containing composite metal oxide having a spinel structure lithium manganese oxide (LiMn ₂ O ₄₎ and the substituting a part of Mn with other transition metal _{Li [Mn 3/2 M 1} /2] O 4 ( where M, Cr , Fe, Co, Ni, Cu, etc.). As the lithium-containing composite metal oxide having an olivine structure, Li _X MPO ₄ (wherein M is at least one element selected from the group consisting of Mn, Fe, Co, Ni, Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, B, and Mo, and 0 < = X < = 2).

As the organic compound, for example, a conductive polymer such as polyacetylene or poly-p-phenylene may be used. The iron-based oxide lacking the electric conductivity may be used as the positive electrode active material covered with the carbon material by causing the carbon source material to exist at the time of the reduction calcination. These compounds may be partially substituted by an element. The positive electrode active material may be a mixture of the inorganic compound and the organic compound.

The positive electrode active material in the case where the electrochemical device is a lithium ion capacitor may be one capable of reversibly supporting lithium ions and anions such as tetrafluoroborate. Concretely, carbon isotopes can be preferably used, and electrode active materials used in electric double-layer capacitors can be widely used. Specific examples of the carbon isotopes include activated carbon, polyacene (PAS), carbon whiskers, carbon nanotubes, and graphite.

Examples of the negative electrode active material in the case where the electrochemical device of the present invention is a lithium ion secondary battery include carbonaceous materials such as amorphous carbon, graphite, natural graphite, mesocarbon microbeads, and pitch-based carbon fibers; Conductive polymers such as polyacene; Metals such as silicon, tin, zinc, manganese, iron, and nickel, or alloys thereof; Oxides or sulfates of said metals or alloys; Metal lithium; Lithium alloys such as Li-Al, Li-Bi-Cd, and Li-Sn-Cd; Lithium transition metal nitride; Silicon, and the like. As the negative electrode active material, a particle surface of the negative electrode active material to which a conductive agent is adhered by, for example, a mechanical modification method may be used. The negative electrode active material may be used singly or in combination of two or more of them in an arbitrary ratio.

As the negative electrode active material that is preferably used when the electrochemical device is a lithium ion capacitor, the negative electrode active material formed from the carbon may be mentioned.

The particle diameter of the electrode active material particles is appropriately selected in view of balance with other components of the electrochemical device. Among them, the D50 average particle size based on the volume of the electrode active material particles is preferably 1 to 50 占 퐉, more preferably 15 to 30 占 퐉, from the viewpoint of improvement of the battery characteristics such as initial efficiency, load characteristics and cycle characteristics.

The content of the electrode active material in the electrode active material layer is preferably from the viewpoint of increasing the capacity of the lithium ion secondary battery and improving the flexibility of the electrode and the binding property between the collector and the electrode active material layer Is 90 to 99.9% by weight, and more preferably 95 to 99% by weight.

(Conductive agent)

Examples of the conductive agent that is optionally used in the present invention include peryne black, acetylene black (hereinafter sometimes abbreviated as " AB "), and Ketjen black (available from Akzo Nobel Chemicals, Carbon nanotubes, carbon nanohorns, and graphenes are preferably used. Of these, acetylene black is more preferable. The average particle diameter of the conductive agent is not particularly limited, but is preferably smaller than the average particle size of the electrode active material, preferably 0.001 to 10 mu m, more preferably 0.005 to 5 mu m, from the viewpoint of exhibiting sufficient conductivity with a smaller usage amount. Mu] m, more preferably 0.01 to 1 [mu] m.

The amount of the conductive agent used in the case of adding the conductive agent is preferably 1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the electrode active material.

(Method for producing particle composite)

The particle composite is obtained by dry mixing a binder for an electrode, an electrode active material, and a conductive agent to be used if necessary. The term " dry mixing " used herein means mixing the electrode binder, the electrode active material and, if necessary, the conductive agent to be used, using a mixer. Specifically, the mixing means that the solid concentration during mixing is 99 wt% or more . Specific mixing methods include a container stirring method using a rocking mixer, a tumbler mixer or the like in which the container itself is mixed by shaking, rotating, or vibrating; A horizontal cylindrical mixer, a V-shaped mixer, a ribbon-type mixer, a cone-shaped screw mixer, a high-speed flow mixer, and a rotary disk mixer, which are mixers equipped with wings, Mechanical stirring using a high-speed rotary blade mixer or the like; Airflow agitation in which powders are mixed in a fluidized bed using a swirling flow by a compressed gas; And the like. These mechanisms may be used alone or in combination. It is also possible to carry out the smoothing to such an extent that cohesion is solved by induction after dry mixing. By dry mixing, the dispersion of the electrochemical device electrode particle composite is maintained satisfactorily, and further, physical properties such as coating accuracy are improved.

The ratio (Da / Db) of the D50 average particle diameter (Da) based on the volume of the particle composite of the present invention to the D50 average particle diameter (Db) based on the volume of the electrode active material is preferably 0.5 to 2, more preferably 0.8 ~ 2. That is, it is preferable that a plurality of electrode active materials are not complex.

(Electrochemical device electrode)

The electrochemical device electrode of the present invention is an electrode formed by laminating an electrode active material layer containing the above-described particle composite on a current collector. As the material of the current collector, for example, metal, carbon, conductive polymer, or the like can be used, and a metal is preferably used. As the metal, copper, aluminum, platinum, nickel, tantalum, titanium, stainless steel and other alloys are usually used. Of these, copper, aluminum or an aluminum alloy is preferably used from the viewpoints of conductivity and voltage resistance. When high withstand voltage is required, aluminum of high purity disclosed in Japanese Laid-Open Patent Publication No. 2001-176757 can be preferably used. The collector may be a film or a sheet. The thickness of the collector is appropriately selected depending on the intended use, but is preferably 1 to 200 占 퐉, more preferably 5 to 100 占 퐉, and still more preferably 10 to 50 占 퐉.

When the electrode active material layer is laminated on the current collector, the particle composite may be formed into a sheet and subsequently laminated on the current collector. However, a method of directly pressing the particle composite on the current collector is preferable. As a method of press-forming, for example, a roll-type press-molding apparatus provided with a pair of rolls is used, and a particle composite is fed to a roll-type press-molding apparatus by a feeding device such as a screw feeder while the current- A roll pressing method in which an electrode active material layer is formed on a collector, a method in which a particle composite is dispersed on a current collector, the particle composite is uniformly adjusted by using a blade or the like, And a method in which the mold is pressurized and molded. Of these, a roll pressing method is preferred. Particularly, since the particle composite of the present invention has a high fluidity, it is possible to supply the fluid to a constant amount feeder, form the powder layer after making the powder layer homogeneous by using a blade, or the like, It becomes.

The roll temperature at the time of performing roll pressing is preferably 25 to 200 占 폚, more preferably 50 to 150 占 폚, and still more preferably 50 to 150 占 폚, from the viewpoint that sufficient adhesion between the electrode active material layer and the current collector can be obtained 80 to 120 ° C. The press line pressure between the rolls during roll press forming is preferably 10 to 1000 kN / m, more preferably 200 to 900 kN / m, more preferably 200 to 900 kN / m, from the viewpoint of improving the uniformity of the thickness of the electrode active material layer. More preferably 300 to 600 kN / m. The molding speed in roll pressing is preferably 0.1 to 20 m / min, more preferably 4 to 10 m / min.

In order to eliminate variations in the thickness of the formed electrochemical device electrode and to increase the density of the electrode active material layer to increase its capacity, post-pressurization may be further performed if necessary. As a post-pressurizing method, a press process by a roll is preferable. In the roll press step, two cylindrical rolls are arranged in parallel at upper and lower intervals in a narrow space, and the rolls are rotated in the opposite directions, and the electrodes are pressed into each other by engaging them. At this time, if necessary, the temperature of the roll may be adjusted by heating or cooling.

(Electrochemical device)

The electrochemical device of the present invention uses an electrochemical device electrode obtained as described above in at least one of a positive electrode and a negative electrode, and further includes a separator and an electrolytic solution. Examples of the electrochemical device include a lithium ion secondary battery and a lithium ion capacitor.

(Separator)

As the separator, for example, a microporous film or nonwoven fabric comprising a polyolefin resin such as polyethylene or polypropylene, or an aromatic polyamide resin; A porous resin coat including an inorganic ceramic powder; Etc. may be used. Specific examples thereof include a microporous membrane made of a resin such as a polyolefin (polyethylene, polypropylene, polybutene, polyvinyl chloride), a mixture thereof, or a copolymer thereof; A microporous film made of a resin such as polyethylene terephthalate, polycycloolefin, polyether sulfone, polyamide, polyimide, polyimide amide, polyaramid, polycycloolefin, nylon, polytetrafluoroethylene and the like; Woven or nonwoven fabric of polyolefin type fibers; And aggregates of insulating substance particles. Among them, a microporous membrane made of a polyolefin resin is preferable because the film thickness of the entire separator can be made thinner and the capacity per volume can be increased by increasing the active material ratio in the lithium ion secondary battery.

The thickness of the separator is preferably 0.5 to 40 占 퐉, more preferably 0.5 to 40 占 퐉, from the viewpoint of reducing the internal resistance by the separator in the lithium ion secondary battery and the workability in producing the lithium ion secondary battery, More preferably 1 to 30 占 퐉, and still more preferably 1 to 25 占 퐉.

(Electrolytic solution)

As the electrolyte for a lithium ion secondary battery, for example, a nonaqueous electrolyte solution in which a supporting electrolyte is dissolved in a nonaqueous solvent is used. As the supporting electrolyte, a lithium salt is preferably used. The lithium salt is, for example, _{LiPF 6, LiAsF 6, LiBF 4} , LiSbF 6, LiAlCl 4, LiClO 4, CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF 3 CO) 2 NLi, and the like _{(CF 3 SO 2) 2 NLi} , (C 2 F 5 SO 2) NLi. In particular, the _{LiPF 6, LiClO 4, CF 3} SO 3 Li indicating a high degree of dissociation easily soluble in solvents. These may be used singly or in combination of two or more in an arbitrary ratio. The higher the degree of dissociation of the supporting electrolyte, the higher the lithium ion conductivity. Therefore, the lithium ion conductivity can be controlled by the type of the supporting electrolyte.

The concentration of the supporting electrolyte in the electrolytic solution is preferably 0.5 to 2.5 mol / l depending on the type of the supporting electrolyte. If the concentration of the supporting electrolyte is too low or too high, the ionic conductivity may be lowered.

The nonaqueous solvent is not particularly limited as long as it can dissolve the supporting electrolyte. Examples of the non-aqueous solvent include carbonates such as dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate (BC) and methyl ethyl carbonate (MEC); esters such as? -butyrolactone and methyl formate; Ethers such as 1,2-dimethoxyethane and tetrahydrofuran; Sulfur-containing compounds such as sulfolane and dimethylsulfoxide; And an ionic liquid which is also used as a supporting electrolyte. Of these, carbonates are preferable because of high dielectric constant and stable wide potential range. As the non-aqueous solvent, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. Generally, the lower the viscosity of the non-aqueous solvent, the higher the lithium ion conductivity and the higher the dielectric constant, the higher the solubility of the supporting electrolyte. However, since both have a tradeoff relationship, the lithium ion conductivity can be controlled by the kind and mixing ratio of the solvent It is good to use. The non-aqueous solvent may be a combination of all or part of hydrogen substituted with fluorine, or a total amount thereof.

The electrolytic solution may contain an additive. As the additive, for example, carbonate such as vinylene carbonate (VC); Sulfur-containing compounds such as ethylene sulfide (ES); And fluorine-containing compounds such as fluoroethylene carbonate (FEC). One kind of additives may be used alone, or two or more kinds of additives may be used in combination at an arbitrary ratio.

As the electrolyte solution for a lithium ion capacitor, the same electrolyte solution as can be used for the above-described lithium ion secondary battery can be used.

(Manufacturing Method of Electrochemical Device)

As a specific method for producing an electrochemical device such as a lithium ion secondary battery or a lithium ion capacitor, for example, a positive electrode and a negative electrode are superimposed with a separator interposed therebetween, and this is wrapped or folded according to the shape of the battery, And a method in which an electrolyte is injected into the battery container to seal the battery container. Expanded metal as needed; An overcurrent prevention element such as a fuse or a PTC element; A lead plate or the like may be inserted so as to prevent an increase in pressure inside the battery and overcharge discharge. The shape of the lithium ion secondary battery may be a coin type, a button type, a sheet type, a cylindrical type, a square type, or a flat type. The material of the battery container is not particularly limited as long as it inhibits moisture penetration into the inside of the battery and is made of a metal or aluminum laminate.

According to the binder for an electrochemical device electrode according to the present embodiment, the productivity of the electrode is excellent, and the thickness precision and flexibility of the obtained electrode are good. In addition, since the electrochemical device electrode of the present invention does not use a dispersing agent such as carboxymethyl cellulose, the resistance of the resulting electrochemical device can be lowered.

Also, by setting the glass transition temperature of the binder for electrodes to a predetermined range, fluidity can be ensured even if the obtained particle composite has a small particle diameter, so that the thickness precision of the electrode can be secured. Further, by setting the glass transition temperature of the binder for the electrochemical device electrode within a predetermined range, strength and flexibility of the obtained electrode can be secured.

In addition, since the slurry is not used in obtaining the particle composite, the energy for production can be reduced. Further, continuous operation is easy, and the yield can be increased.

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples, and can be carried out without departing from the scope of the present invention and the scope of the present invention. . In the following description, "% " and " part " representing amounts are based on weight unless otherwise specified.

In the Examples and Comparative Examples, the glass transition temperature (Tg) of the binder for the electrode (negative electrode binder or positive electrode binder) was measured, the D50 average particle diameter (primary particle diameter) , A D50 average particle diameter (Da) based on the volume of the electrode active material and a D50 average particle diameter (Db) based on the volume of the electrode active material, measurement of volatile matter content at 120 캜 of the electrode binder, measurement of the lowest film forming temperature of the electrode binder, The measurement was carried out as follows.

<Glass transition temperature>

The glass transition temperature (Tg) of the binder for the electrode was measured on the basis of JIS K 7121: 1987 using a differential scanning calorimeter (DSC6220SII, manufactured by Nanotechnology Co., Ltd.).

&Lt; Measurement of primary particle size &

(Binder for negative electrode 1 to 12 and positive electrode binder 1 to 13) prepared in Examples and Comparative Examples were added to a 1% aqueous solution of sodium alkylbenzenesulfonate, dispersed by ultrasonic waves, and then dispersed in a Coulter counter And the particle size corresponding to the 50% integrated value was defined as a D50 average particle size (primary particle size) based on the volume of the binder for the electrode (primary particle size) by LS230 (particle size analyzer manufactured by Coulter Inc.).

&Lt; Measurement of Da and Db &gt;

The D50 average particle diameter (Da) based on the volume of the particle composite prepared in Examples and Comparative Examples was determined by the integrated particle size distribution of the dry type using a laser diffraction / scattering type particle size distribution measuring apparatus (Microtrack MT3200II; Nikkiso) And the D50 average particle size (Db) based on the volume of the electrode active material used in the comparative example were measured to calculate a ratio (Da / Db).

<Measurement of volatile content at 120 ° C>

The binder for powder negative electrode 1 to 12 and the powder positive electrode binder 1 to 13 prepared in Examples and Comparative Examples were respectively placed in an oven set at 120 DEG C and the weight of the binder was measured every 10 minutes, And the end was reached. The weight change rate (decrease) from the initial weight to the end of the measurement was determined as the volatile content at 120 캜.

<Lowermost film forming temperature>

The test was conducted in accordance with ISO2115 using the lowest film-forming temperature measuring device (MFFTB90; manufactured by RHOPOINT).

<Measurement of shape>

The binder for the powder electrode was observed with an SEM to randomly select 30 particles visible in the image, and the average short axis and average long axis of each particle were determined to calculate the average sphericity. At this time, spherical aberration of 80% or more and average spherical aberration of less than 80% were made non-spherical.

In Examples and Comparative Examples, evaluation of electrode precision, electrode flexibility, and rate characteristics were carried out as follows.

<Electrode Precision>

(10) cm in the TD direction (lateral direction) and 10 cm in the MD direction (longitudinal direction) of the electrode active material layer prepared in the examples and the comparative example, three points equally in the TD direction and three points uniformly in the MD direction The film thickness of the point was measured. When the average value of the film thickness is A and the thickness most distant from the average value is B, the electrode thickness irregularity is calculated by the following formula.

Electrode thickness non-uniformity precision (%) = (| A-B |) x 100 / A

This was regarded as the electrode precision and evaluated according to the following criteria. The results are shown in Tables 1 and 2. The smaller this value is, the better the formability is.

A: Less than 4%

B: 4% or more and less than 9%

C: 9% or more and less than 15%

D: 15% or more

E: There is a hole in the electrode.

&Lt; Flexibility of electrodes &gt;

The electrodes of the electrochemical device fabricated in Examples and Comparative Examples were cut into 1 cm x 8 cm, wound on metal rods of 3 mm, 4 mm, and 5 mm in diameter, respectively, and cracks generated were evaluated as follows. The results are shown in Tables 1 and 2. The smaller the crack, the better the flexibility, i.e., the better the electrode strength.

A: No crack in metal rod with diameter of 3 mm

B: There is no crack in a metal rod with a diameter of 4 mm, but there is a crack in a metal rod with a diameter of 3 mm

C: There is a crack at a diameter of 5 mm

<Rate characteristics>

The laminate cell type lithium ion secondary cells prepared in the examples and the comparative examples were left to stand for 5 hours after the electrolytic solution was poured and charged to a cell voltage of 3.65 V at a constant current of 0.2 C under an atmosphere of 25 캜, Deg.] C and subjected to aging treatment for 12 hours, and discharge was carried out at a cell voltage of 3.00 V by a constant current method of 0.2 C in an atmosphere of 25 deg.

Thereafter, charging was performed at 4.2 V and 0.2 C in an atmosphere of 25 캜, and discharging was performed at 0.2 C and 2.0 C rates. At that time, the discharge capacity when the discharge rate, _0.2 C (discharging capacity at the time of 0.2 C), C _{2 .0} defined as (discharging capacity at 2.0 C hour) _{and, ΔC = C 2 .0 / C} 0 .2 when Of the discharge capacity x 100 (%) was determined and evaluated according to the following criteria. The results are shown in Tables 1 and 2. The higher the value of the capacitance change rate? C, the better the discharge rate characteristic (rate characteristic).

A: ΔC is 83% or more

B:? C is 82% or more and less than 83%

C: ΔC is 80% or more and less than 82%

D: ΔC is less than 80%

&Lt; Example 1 &gt;

(Production of particulate polymer 1 for negative electrode)

78 parts of styrene (hereinafter may be abbreviated as &quot; ST &quot;), 19 parts of 1,3-butadiene (hereinafter sometimes abbreviated as &quot; BD &quot;), (DOWEX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier was added in an amount of 0.4 part by weight in terms of solid content, ion-exchanged water 150 , 0.3 part of t-dodecyl mercaptan (hereinafter may be abbreviated as "TDM") as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were placed. After sufficiently stirring, the mixture was heated to 75 ° C to initiate polymerization Respectively. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of particulate polymer 1 for negative electrode (styrene-butadiene copolymer; hereinafter sometimes abbreviated as "SBR"). The minimum film-forming temperature of the particulate polymer 1 for negative electrode was 55 占 폚, the glass transition temperature (Tg) was 50 占 폚, and the primary particle size was 132 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 1 at 40 占 폚 using a rotary evaporator, and then dried in a vacuum dryer at 40 占 폚 and 0.6 占 ㎪. Thereafter, the dried particulate polymer 1 for negative electrode was pulverized with a mortar to obtain a powdery negative electrode binder 1. The volatile matter content at 120 캜 of the negative electrode binder 1 in the powder form was 0.1%.

(Preparation of particle composite)

As the negative electrode active material, 98.8 parts of artificial graphite (average particle diameter: 24.5 mu m, distance between graphite layers (plane interval (d value) of (002) plane by X-ray diffraction method: 0.354 nm) 1.2 parts and Henschel mixer (manufactured by Mitsui Miike) for 10 minutes, and a negative electrode binder was attached to the negative electrode active material to obtain a particle composite.

(Preparation of negative electrode)

The above-obtained particle composite was subjected to a pressing roll (roll temperature 100 (hot press)) of a roll press machine (&quot; press cutting rough surface hot roll &quot; manufactured by Hirono Kiken Kogyo Co., Ltd.) using a quantitative feeder (Nikka Spray KV,占 폚, press line pressure: 500 kN / m). A copper foil having a thickness of 20 占 퐉 was inserted between press rolls, the particle composite supplied from the quantitative feeder was adhered to a copper foil and pressed at a forming speed of 1.5 m / min to obtain a negative electrode having a negative active material .

(Preparation of slurry for positive electrode and positive electrode)

(PVDF; "KF-1100" manufactured by Kureha Chemical Industries, Ltd.) as a positive electrode binder was added to 92 parts of LiCoO ₂ as a positive electrode active material and ₂ parts of acetylene black (HS-100 manufactured by Denki Kagaku Kogyo Co., Ltd.) ) And 20 parts of N-methylpyrrolidone were added, and the mixture was mixed with a planetary mixer to obtain a positive electrode slurry. The slurry for positive electrode was applied to an aluminum foil having a thickness of 18 占 퐉, dried at 120 占 폚 for 30 minutes, and then rolled to obtain a positive electrode having a thickness of 60 占 퐉.

(Preparation of separator)

A single-layered polypropylene separator (width 65 mm, length 500 mm, thickness 25 占 퐉, manufactured by the dry method, porosity of 55%) was cut out in a square of 5 占 5 cm2.

(Production of lithium ion secondary battery)

As an exterior of the battery, an aluminum-containing sheath was prepared. The positive electrode thus obtained was cut into a square having a size of 4 x 4 cm 2, and the surface of the current collector side was arranged so as to be in contact with the aluminum-containing sheath. On the surface of the positive electrode active material layer of the positive electrode obtained above, the square separator obtained in the above was disposed. Further, the negative electrode obtained above was cut into a square of 4.2 x 4.2 cm &lt; 2 &gt; and placed on the separator so that the surface of the negative electrode active material layer side was facing the separator. Further, a 1.0 mol / l LiPF ₆ solution containing 2.0% of vinylene carbonate was charged. The solvent of the LiPF ₆ solution is a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC / EMC = 3/7 (volume ratio)). Further, in order to seal the openings of the aluminum foil, a heat seal was performed at 150 占 폚 to remove the aluminum sheath to produce a laminate type lithium ion secondary battery (laminate type cell).

&Lt; Example 2 &gt;

(Production of particulate polymer 2 for negative electrode)

74.5 parts of styrene, 22.5 parts of 1,3-butadiene, 3 parts of itaconic acid, 3 parts of alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier was added to a 5- 0.4 part of a solid equivalent, 150 parts of ion-exchanged water, 0.3 part of t-dodecylmercaptan as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were put into the flask, sufficiently stirred and then heated to 75 deg. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of particulate polymer 2 for negative electrode. The lowest film-forming temperature of the particulate polymer 2 was 40 占 폚, the glass transition temperature (Tg) was 40 占 폚, and the primary particle diameter was 135 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 2 at 25 캜 using a rotary evaporator, and then dried in a vacuum dryer at 25 캜 and 0.6.. Thereafter, the dried negative electrode particulate polymer 2 was pulverized with a mortar to obtain a negative electrode binder 2 in powder form. The volatile matter at 120 캜 of the negative electrode binder 2 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 2 was used.

&Lt; Example 3 &gt;

(Preparation of particulate polymer 3 for negative electrode)

85 parts of styrene, 12 parts of 1,3-butadiene, 3 parts of itaconic acid and 3 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a 5- 0.4 part of a solid equivalent, 150 parts of ion-exchanged water, 0.3 part of t-dodecylmercaptan as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were put into the flask, sufficiently stirred and then heated to 75 deg. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of Polymer 3 for negative electrode. The minimum film-forming temperature of the particulate polymer 3 for negative electrode was 88 deg. C, the glass transition temperature (Tg) was 70 deg. C, and the primary particle diameter was 134 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative electrode particle polymer 3 at 60 캜 using a rotary evaporator, and then dried in a vacuum drier at 60 캜 and 0.6.. Thereafter, the dried negative electrode particulate polymer 3 was pulverized with a mortar to obtain a negative electrode binder 3 for a negative electrode. The volatile matter content of the negative electrode binder 3 at 120 캜 was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 3 was used.

<Example 4>

(Production of particulate polymer 4 for negative electrode)

78 parts of styrene, 19 parts of 1,3-butadiene, 3 parts of itaconic acid, and 5 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a 5- 2.0 part of a solid equivalent, 150 parts of ion-exchanged water, 0.3 part of t-dodecyl mercaptan as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were put into the flask. After sufficiently stirring, the mixture was heated to 75 deg. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of Polymer 4 for negative electrode. The minimum film-forming temperature of the particulate polymer 4 for the negative electrode was 53 캜, the glass transition temperature (Tg) was 50 캜, and the primary particle diameter was 80 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 4 at 40 占 폚 using a rotary evaporator, and then dried in a vacuum dryer at 40 占 폚, 0.6 占 ㎪. Thereafter, the dried negative electrode particulate polymer 4 was pulverized with a mortar to obtain a powdery negative electrode binder 4. The volatile matter at 120 캜 of the negative electrode binder 4 in the form of a powder was 0.4%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 4 was used.

&Lt; Example 5 &gt;

(Production of particulate polymer 5 for negative electrode)

210 parts of ion-exchanged water was charged into a 5 ㎫ pressure vessel equipped with a stirrer, and heated to 75 캜 with stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 78 parts of styrene, 19 parts of 1,3-butadiene, 3 parts of itaconic acid, 3 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1 , Dow Chemical Co., Ltd.) in an amount corresponding to a solid content of 0.4 part, t-dodecylmercaptan 0.3 part as a chain transfer agent, and 26 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over a period of 3.5 hours in a stirred and emulsified state, and the reaction was continued until the polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 5 for negative electrode. The minimum film-forming temperature of the particulate polymer 5 for negative electrode was 56 占 폚, the glass transition temperature (Tg) was 50 占 폚, and the primary particle size was 304 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 5 at 40 占 폚 using a rotary evaporator, followed by drying in a vacuum drier at 40 占 폚 and 0.6 占.. Thereafter, the dried negative electrode particulate polymer 5 was pulverized with a mortar to obtain a powdery negative electrode binder 5. The volatile matter content of the negative electrode binder 5 at 120 ° C in the powder form was 0.1%.

Except for using the negative electrode binder 5, the negative electrode and the lithium ion secondary battery were produced in the same manner as in Example 1.

&Lt; Example 6 &gt;

(Production of particulate polymer 6 for negative electrode)

210 parts of ion-exchanged water was charged into a 5 ㎫ pressure vessel equipped with a stirrer, and heated to 75 캜 with stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 78 parts of styrene, 19 parts of 1,3-butadiene, 3 parts of itaconic acid, 3 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1 , Manufactured by DOW CHEMICALS CO., LTD.) In an amount corresponding to a solid content of 0.2 part, t-dodecylmercaptan 0.3 part as a chain transfer agent, and 26 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over a period of 3.5 hours in a stirred and emulsified state, and the reaction was continued until the polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 6 for negative electrode. The minimum film-forming temperature of the particulate polymer 6 for negative electrode was 56 占 폚, the glass transition temperature (Tg) was 50 占 폚, and the primary particle diameter was 625 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 6 at 40 占 폚 using a rotary evaporator, and then dried in a vacuum dryer at 40 占 폚 and 0.6 占 ㎪. Thereafter, the dried negative electrode particulate polymer 6 was pulverized with a mortar to obtain a powdery negative electrode binder 6. The volatile matter content of the negative electrode binder 6 at 120 ° C in the powder form was 0.1%.

A negative electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 6 was used.

&Lt; Example 7 &gt;

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 1 at 40 占 폚 using a rotary evaporator. Thereafter, the particulate polymer was dried and pulverized in the same manner as in Example 1 except that the drying was not carried out under the conditions of 40 캜 and 0.6 진 in a vacuum drier to obtain a powdery negative electrode binder 7. The volatile matter content at 120 캜 of the negative electrode binder 7 in powder form was 0.8%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 7 was used.

&Lt; Comparative Example 1 &

(Production of particulate polymer 7 for negative electrode)

70 parts of styrene, 27 parts of 1,3-butadiene, 3 parts of itaconic acid, and 3 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a 5- 0.4 part of a solid equivalent, 150 parts of ion-exchanged water, 0.3 part of t-dodecylmercaptan as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were put into the flask, sufficiently stirred and then heated to 75 deg. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of Polymer 7 for negative electrode. The lowest film-forming temperature of the negative electrode particle polymer 7 was 27 캜, the glass transition temperature (Tg) was 30 캜, and the primary particle diameter was 130 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative electrode particle polymer 7 at 20 占 폚 using a rotary evaporator, and then dried in a vacuum dryer at 20 占 폚 and 0.6 占 ㎪. Thereafter, the dried negative electrode particulate polymer 7 was pulverized with a mortar to obtain a powdery negative electrode binder 8 having a high cohesiveness. The volatile matter content at 120 캜 of the negative electrode binder 8 in the powder form was 0.1%.

A negative electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 8 was used.

&Lt; Comparative Example 2 &

(Production of particulate polymer 8 for negative electrode)

94 parts of styrene, 3 parts of 1,3-butadiene, 3 parts of itaconic acid and 3 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a 5- 0.4 part as a solid content, 150 parts of ion-exchanged water and 0.5 part of potassium persulfate as a polymerization initiator were put into the flask and sufficiently stirred, followed by heating to 75 DEG C to initiate polymerization. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain an aqueous dispersion of Polymer 8 for negative electrode. The lowest film-forming temperature of the particulate polymer 8 for negative electrode was 120 캜, the glass transition temperature (Tg) was 100 캜, and the primary particle diameter was 135 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the negative electrode particulate polymer 8 at 80 캜 using a rotary evaporator, and then dried in a vacuum dryer at 80 캜 and 0.6.. Thereafter, the dry negative electrode particulate polymer 8 was pulverized with a mortar to obtain a powdery negative electrode binder 9.

A negative electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 9 was used.

&Lt; Comparative Example 3 &

(Production of particulate polymer 9 for negative electrode)

To 100 parts by weight of the polymer, 10 parts by weight of the polymer was added to the aqueous dispersion of the negative-electrode particulate polymer 1 at a weight ratio of 100 parts, and emulsified at 15000 rpm by an emulsifying dispersing device (MILDER MDN303V; Thereafter, the solvent was removed from the emulsion using a rotary evaporator to obtain an aqueous dispersion of Polymer 9 for negative electrode. The lowest film-forming temperature of the negative-electrode particulate polymer 9 was 53 ° C, the glass transition temperature (Tg) was 50 ° C, and the primary particle size was 3020 nm.

(Drying and crushing of the particulate polymer)

Water was removed from the aqueous dispersion of the particulate polymer 9 at 40 캜 using a rotary evaporator, and then dried in a vacuum dryer at 40 캜 and 0.6.. Thereafter, the dried negative electrode particulate polymer 9 was pulverized with a mortar to obtain a powdery negative electrode binder 10. The volatile matter content at 120 캜 of the negative electrode binder 10 in the powder form was 0.1%.

A negative electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 10 was used.

&Lt; Comparative Example 4 &

When water was removed from the aqueous dispersion of the negative electrode particulate polymer 1 at 40 占 폚 using a rotary evaporator, removal of water was stopped on the way to obtain a negative electrode binder 11 for the negative electrode. The volatile matter at 120 캜 of the negative electrode binder 11 in the form of powder was 2%.

A negative electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 11 was used.

&Lt; Comparative Example 5 &

Water was removed from the aqueous dispersion of the negative-electrode particulate polymer 1 at 60 占 폚 using a rotary evaporator, and then dried in a vacuum dryer at 60 占 폚 and 0.6 占 ㎪. Thereafter, the particulate polymer 1 for a negative electrode was pulverized by means of a mortar, and then pulverized by a jet mill until the average particle diameter became about 5000 nm to obtain a powdery negative electrode binder 12. The volatile matter content of the negative electrode binder 12 at 120 ° C in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 1 except that the negative electrode binder 12 was used.

&Lt; Example 8 &gt;

(Production of particulate polymer 1 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 20 parts of butyl acrylate (hereinafter abbreviated as &quot; BA &quot;) and 20 parts of ethyl methacrylate (hereinafter abbreviated as &quot; EMA &quot;) were charged in a vessel different from the above equipped with a mechanical stirrer (Hereinafter sometimes abbreviated as "AMA") 0.1 part, methacrylic acid (hereinafter may be abbreviated as "AMA") 0.1 part, and emulsion 30 , 1.0 part of an alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by Dow Chemical Company) in an amount corresponding to a solid content, and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 1 for positive electrode (acrylic polymer; hereinafter sometimes abbreviated as "acrylic"). The lowest film-forming temperature of the particulate polymer 1 for positive electrode was 45 占 폚, the glass transition temperature (Tg) was 40 占 폚, and the primary particle diameter was 310 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 1 was subjected to a spraying operation using a rotary disk-type atomizer (diameter: 65 mm) at a rotation speed of 25,000 rpm and a hot air temperature of 40 占 폚 in a spray dryer (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 30 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 1. The volatile matter content at 120 캜 of the positive electrode binder 1 in the powder form was 0.1%.

(Preparation of particle composite)

92.5 parts of NMC (111) as a positive electrode active material, 6 parts of acetylene black as a conductive agent and 1.5 parts of the binder for a positive electrode in terms of solid content in an amount of 10 parts were mixed using a Henschel mixer (manufactured by Mitsui Miike) Was attached to the positive electrode binder to obtain a particle composite.

(Preparation of positive electrode)

The above-obtained particle composite was subjected to a press roll (roll temperature of 100 占 폚, press line pressure of 500 kN / cm) using a quantitative feeder (Nikka Spray KV, manufactured by Nikka Corporation) m. An aluminum foil having a thickness of 20 占 퐉 was inserted between the press rolls, the particle composite supplied from the quantitative feeder was adhered to the aluminum foil and pressure-formed at a molding speed of 1.5 m / min to obtain a positive electrode having a positive electrode active material .

(Preparation of negative electrode slurry and negative electrode)

96 parts of styrene-butadiene copolymer latex (BM-400B) as artificial graphite (average particle diameter: 24.5 占 퐉, distance between graphite layers (plane spacing of (002) (DN-800H, produced by Daicel Chemical Industries, Ltd.) in an amount of 1.0 part by weight in terms of solid content, and ion-exchanged water was further added thereto so as to have a solid concentration of 50% To obtain a slurry for a mixed dispersion type negative electrode. The slurry for negative electrode was applied to a copper foil having a thickness of 18 占 퐉 and dried at 120 占 폚 for 30 minutes, followed by roll pressing to obtain a negative electrode having a thickness of 50 占 퐉.

(Preparation of separator)

A single-layered polypropylene separator (width 65 mm, length 500 mm, thickness 25 占 퐉, manufactured by the dry method, porosity of 55%) was cut out in a square of 5 占 5 cm2.

(Production of lithium ion secondary battery)

As an exterior of the battery, an aluminum-containing sheath was prepared. The positive electrode thus obtained was cut into a square having a size of 4 x 4 cm 2, and the surface of the current collector side was arranged so as to be in contact with the aluminum-containing sheath. On the surface of the positive electrode active material layer of the positive electrode obtained above, the square separator obtained in the above was disposed. Further, the negative electrode obtained above was cut into a square of 4.2 x 4.2 cm &lt; 2 &gt; and placed on the separator so that the surface of the negative electrode active material layer side was facing the separator. Further, a 1.0 mol / l LiPF ₆ solution containing 2.0% of vinylene carbonate was charged. The solvent of the LiPF ₆ solution is a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC / EMC = 3/7 (volume ratio)). Further, in order to seal the openings of the aluminum foil, a heat seal was performed at 150 占 폚 to obtain an aluminum sheath to obtain a laminate type lithium ion secondary battery (laminate type cell).

&Lt; Example 9 &gt;

(Preparation of particulate polymer 2 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 12 parts of butyl acrylate, 85.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate were added to a vessel different from the above equipped with the mechanical stirrer in a nitrogen atmosphere, 1.0 part of alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by DOW CHEMICAL CO., LTD.) In an amount corresponding to a solid content and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 2 for positive electrode. The lowest film-forming temperature of the particulate polymer 2 for positive electrode was 52 占 폚, the glass transition temperature (Tg) was 50 占 폚, and the primary particle diameter was 319 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 2 was subjected to a spinning method using a rotary disc type atomizer (diameter 65 mm) at a rotation speed of 25,000 rpm and a hot air temperature of 40 ° C in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 40 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 2. The volatile matter content at 120 캜 of the powdery positive electrode binder 2 was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 2 was used.

&Lt; Example 10 &gt;

(Preparation of particulate polymer 3 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, in a vessel different from the above equipped with the mechanical stirrer, 6 parts of butyl acrylate, 91.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate, 1.0 part of alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by DOW CHEMICAL CO., LTD.) In an amount corresponding to a solid content and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% Thereby obtaining an aqueous dispersion of the particulate polymer 3 for positive electrode. The lowest film-forming temperature of the particulate polymer 3 for positive electrode was 65 占 폚, the glass transition temperature (Tg) was 60 占 폚, and the primary particle diameter was 331 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 3 was subjected to a spraying operation using a rotary disk type atomizer (diameter 65 mm) at a rotation speed of 25,000 rpm and a hot air temperature of 40 占 폚 in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 40 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 3. The volatile matter content at 120 캜 of the positive electrode binder 3 in the powder form was 0.1%.

The positive electrode and the lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 3 was used.

&Lt; Example 11 &gt;

(Production of particulate polymer 4 for positive electrode)

210 parts of ion-exchanged water and 30% of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a reactor equipped with a mechanical stirrer and a condenser in a nitrogen atmosphere, 0.5 part was poured in a considerable amount, heated to 70 캜 with stirring, and 25.5 parts of a 1.96% aqueous potassium persulfate solution was added to the reactor. Subsequently, 20 parts of butyl acrylate, 77.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate were added to a container different from the above equipped with the mechanical stirrer in a nitrogen atmosphere, , 0.5 part of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) in an amount corresponding to a solid content, and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 4 for positive electrode. The lowest film-forming temperature of the particulate polymer 4 for positive electrode was 43 占 폚, the glass transition temperature (Tg) was 40 占 폚, and the primary particle diameter was 139 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 4 was subjected to a spinning method using an atomizer (diameter: 65 mm) of a rotating disk system at a rotation speed of 25,000 rpm and a hot air temperature of 40 ° C in a spray dryer (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum dryer at 30 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 4. The volatile matter content at 120 캜 of the positive electrode binder 4 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 4 was used.

&Lt; Example 12 &gt;

(Production of particulate polymer 5 for positive electrode)

210 parts of ion-exchanged water and 30% of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) as an emulsifier were added to a reactor equipped with a mechanical stirrer and a condenser in a nitrogen atmosphere, 0.8 part of a substantial amount was charged and heated to 70 캜 with stirring, and 25.5 parts of a 1.96% aqueous potassium persulfate solution was added to the reactor. Subsequently, 20 parts of butyl acrylate, 77.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate were added to a container different from the above equipped with the mechanical stirrer in a nitrogen atmosphere, 0.8 parts of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) in an amount corresponding to a solid content and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% Thereby obtaining an aqueous dispersion of the particulate polymer 5 for positive electrode. The lowest film-forming temperature of the particulate polymer for positive electrode 5 was 43 占 폚, the glass transition temperature (Tg) was 40 占 폚, and the primary particle diameter was 100 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 5 was prepared by using an atomizer (diameter: 65 mm) of a rotating disc type in a spray drier (manufactured by Okawara Chemical Industry Co., Ltd.) at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜, Dried and assembled, and the obtained particles were dried in a vacuum drier at 30 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 5. The volatile matter at 120 캜 of the powdery positive electrode binder 5 was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 5 was used.

&Lt; Example 13 &gt;

(Production of particulate polymer 6 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 20 parts of butyl acrylate, 77.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate were added to a container different from the above equipped with the mechanical stirrer in a nitrogen atmosphere, 0.4 part of alkyldiphenyl oxide disulfonate (DOWAX (registered trademark) 2A1, manufactured by Dow Chemical Company) in an amount corresponding to a solid content, and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% To obtain an aqueous dispersion of the particulate polymer 6 for positive electrode. The lowest film-forming temperature of the particulate polymer 6 for positive electrode was 48 占 폚, the glass transition temperature (Tg) was 40 占 폚, and the primary particle diameter was 625 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 6 was prepared by using an atomizer (diameter: 65 mm) of a rotating disc type in a spray drier (manufactured by Okawara Chemical Industry Co., Ltd.) at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜, Dried and assembled, and the obtained particles were dried in a vacuum dryer at 30 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 6. The volatile component at 120 캜 of the positive electrode binder 6 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 6 was used.

&Lt; Example 14 &gt;

The aqueous dispersion of the positive electrode particulate polymer 1 was subjected to a spraying operation using a rotary disk-type atomizer (diameter: 65 mm) at a rotation speed of 25,000 rpm and a hot air temperature of 40 占 폚 in a spray dryer (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled to obtain particles. Thereafter, the particulate polymer was dried in the same manner as in Example 8, except that the obtained particles were not dried in a vacuum drier at 30 캜 and 0.6 ㎪, to obtain a powdery positive electrode binder 7. The volatile matter at 120 캜 of the positive electrode binder 7 in the powder form was 0.8%.

The positive electrode and the lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 7 was used.

&Lt; Comparative Example 6 &gt;

(Preparation of particulate polymer 7 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 27.6 parts of butyl acrylate, 70.0 parts of ethyl methacrylate, 2.4 parts of methacrylic acid, 0.1 part of allyl methacrylate, and 30 parts of an emulsifier were added to a container different from the above equipped with a mechanical stirrer under nitrogen atmosphere 1.0 part of alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by DOW CHEMICAL CO., LTD.) In an amount corresponding to a solid content and 22.7 parts of ion-exchanged water were added and stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% Thereby obtaining an aqueous dispersion of the positive electrode particulate polymer 7. The lowest film-forming temperature of the positive electrode particulate polymer 7 was 27 占 폚, the glass transition temperature (Tg) was 30 占 폚, and the primary particle diameter was 307 nm.

(Drying of particulate polymer)

The aqueous dispersion of the particulate polymer for positive electrode 7 was subjected to a spinning method using an atomizer (diameter: 65 mm) of a rotating disc type in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜, Dried and assembled, and the obtained particles were dried in a vacuum drier at 25 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 8. The volatile content at 120 캜 of the positive electrode binder 8 in the powder form was 0.1%.

The positive electrode was prepared and the lithium ion secondary battery was produced in the same manner as in Example 8 except that the positive electrode binder 8 was used.

&Lt; Comparative Example 7 &

(Preparation of particulate polymer 8 for positive electrode)

In a reactor equipped with a mechanical stirrer and a condenser, 210 parts of ion-exchanged water was poured under a nitrogen atmosphere, and the mixture was heated to 70 占 폚 while stirring, and 25.5 parts of a 1.96% potassium persulfate aqueous solution was added to the reactor. Subsequently, 22.5 parts of ethyl methacrylate, 75.0 parts of methyl methacrylate (hereinafter sometimes abbreviated as &quot; MMA &quot;) and 50.0 parts of methacrylic acid 2.4 were added to a vessel different from the above equipped with the mechanical stirrer, , 0.1 part of allyl methacrylate, 1.0 part of alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by Dow Chemical Company) having a concentration of 30% as an emulsifier in an amount corresponding to a solid content of 22 parts And this was stirred and emulsified to prepare a monomer mixture solution. Then, this monomer mixture solution was added to a reactor charged with 210 parts of ion-exchanged water and an aqueous solution of potassium persulfate at a constant rate over 2.5 hours while being stirred and emulsified, and the reaction was continued until polymerization conversion rate reached 95% Thereby obtaining an aqueous dispersion of the particulate polymer 8 for positive electrode. The lowest film-forming temperature of the particulate polymer 8 for positive electrode was 115 占 폚, the glass transition temperature (Tg) was 100 占 폚, and the primary particle diameter was 280 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 8 was subjected to a spinning method using an atomizer (diameter: 65 mm) of a rotary disk method at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜 in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 80 캜 under a condition of 0.6 ㎪ to obtain a powdery positive electrode binder 9. The volatile matter content at 120 캜 of the positive electrode binder 9 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 9 was used.

&Lt; Comparative Example 8 &gt;

(Production of particulate polymer 9 for positive electrode)

A reaction vessel equipped with a mechanical stirrer and a condenser was charged with 831 parts of ion-exchanged water and an alkyldiphenyl oxide disulfonate (DOWEX (registered trademark) 2A1, manufactured by Dow Chemical Company) having a concentration of 30% as an emulsifier in a nitrogen atmosphere, 10 parts were added in a considerable amount, and 6 parts of butyl acrylate, 91.5 parts of ethyl methacrylate, 2.4 parts of methacrylic acid and 0.1 part of allyl methacrylate were added, and the monomer mixture solution was stirred and emulsified. This was heated to 60 DEG C while stirring, and 51 parts of 1.96% aqueous potassium persulfate solution was added to the reactor. The reaction was continued until the polymerization conversion rate reached 98%, and an aqueous dispersion of Polymer Particle 9 for positive electrode was obtained. The lowest film-forming temperature of the positive-electrode particulate polymer 9 was 42 占 폚, the glass transition temperature (Tg) was 60 占 폚, and the primary particle diameter was 50 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 9 was prepared by using an atomizer (diameter: 65 mm) of a rotating disc type in a spray drier (manufactured by Okawara Chemical Industry Co., Ltd.) at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜, Dried and assembled, and the obtained particles were dried in a vacuum dryer at 40 DEG C under a condition of 0.6 DEG C to obtain a powdery positive electrode binder 10. The volatile component at 120 캜 of the positive electrode binder 10 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 10 was used.

&Lt; Comparative Example 9 &

(Production of particulate polymer 10 for positive electrode)

Toluene was added at a weight ratio of 100 parts by weight based on 10 parts by weight of the polymer to the aqueous dispersion of the positive electrode particulate polymer 1 and emulsified at 15000 rpm with an emulsifying dispersing device (MILDER MDN303V; manufactured by Pacific Kagaku). Thereafter, the solvent was removed from the emulsion using a rotary evaporator to obtain an aqueous dispersion of the positive electrode particulate polymer 10. The lowest film-forming temperature of the particulate polymer 10 was 53 캜, the glass transition temperature (Tg) was 40 캜, and the primary particle diameter was 3050 nm.

(Drying of particulate polymer)

The aqueous dispersion of the positive electrode particulate polymer 10 was subjected to a spinning method using an atomizer (diameter: 65 mm) of a rotary disk method at a rotation speed of 25,000 rpm and a hot air temperature of 40 캜 in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 40 캜 and 0.6 ㎪ to obtain a powdery positive electrode binder 11. The volatile matter content at 120 캜 of the positive electrode binder 11 in the powder form was 0.1%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 11 was used.

&Lt; Comparative Example 10 &

The aqueous dispersion of the particulate polymer 1 for positive electrode was set at a rotation speed of 25,000 rpm and a hot air temperature of 30 캜 using an atomizer (diameter: 65 mm) of a rotary disc type in a spray drier (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were vacuum-dried to obtain a powdery positive electrode binder 12. The volatile matter at 120 캜 of the positive electrode binder 12 in the powder form was 2%.

A positive electrode and a lithium ion secondary battery were produced in the same manner as in Example 8 except that the positive electrode binder 12 was used.

&Lt; Comparative Example 11 &

The aqueous dispersion of the positive electrode particulate polymer 1 was subjected to a spraying operation using a rotary disk-type atomizer (diameter: 65 mm) at a rotation speed of 25,000 rpm and a hot air temperature of 40 占 폚 in a spray dryer (manufactured by Okawa Chemical Industry Co., Ltd.) Dried and assembled, and the obtained particles were dried in a vacuum drier at 70 캜 and 0.6.. Thereafter, the particulate polymer 1 for a positive electrode for use in the film was pulverized by pulverization, followed by pulverization with an average jet diameter of about 5000 nm by means of a jet mill to obtain a powdery positive electrode binder 13. The volatile matter at 120 캜 of the positive electrode binder 13 in the powder form was 0.1%.

As shown in Tables 1 and 2, is composed of a polymer having a glass transition temperature of 35 to 80 DEG C and a D50 average particle diameter based on the volume of primary particles of 80 to 1000 nm, and a volatile content at 120 DEG C of less than 1% , And the electrode manufactured using the particle composite including the electrode binder as the powdery composite particle had good electrode precision and flexibility, and the rate characteristics of the lithium ion secondary battery using this electrode were good.

Claims (9)

A glass transition temperature of 35 to 80 DEG C and a D50 average particle diameter based on the volume of primary particles of 80 to 1000 nm and a volatile content at 120 DEG C of less than 1 wt% A binder for an electrochemical device electrode. The method according to claim 1,
Wherein the polymer is obtained by drying an aqueous dispersion of a particulate polymer in which the polymer is dispersed at a temperature lower than the lowest film forming temperature of the particulate polymer. 3. The method according to claim 1 or 2,
A conjugated diene monomer unit, an acrylic ester monomer unit, a methacrylic acid ester monomer unit, an aromatic vinyl monomer unit, an ethylenically unsaturated nitrile monomer unit, an ethylenically unsaturated carboxylic acid monomer unit, an ethylenically unsaturated amide monomer unit, a polyfunctional ethylenic monomer And at least one kind of monomer unit selected from the group consisting of a monomer unit and a monomer unit. A particle composite for an electrochemical device electrode, which is obtained by dry-blending an electrode active material with the binder for an electrochemical device electrode according to any one of claims 1 to 3. (Da / Db) of the D50 average particle diameter (Da) based on the volume of the electrochemical device electrode particle composite according to claim 4 and the D50 average particle diameter (Db) based on the volume of the electrode active material is 0.5 to 2 By weight based on the total weight of the particles. An electrochemical device electrode comprising an electrode active material layer comprising the particle composite for an electrochemical device electrode according to claim 5 laminated on a current collector. The method according to claim 6,
Wherein the electrode active material layer is obtained by press-forming an electrode material including the particle composite for electrochemical device electrode onto the current collector. An electrochemical device comprising the electrochemical device electrode according to claim 6 or 7. The aqueous dispersion containing a particulate polymer having a glass transition temperature of 35 to 80 캜 and a spherical shape having an average particle size D50 of a primary particle volume basis of 80 to 1000 nm dispersed therein is dried at a temperature lower than the lowest film forming temperature of the particulate polymer, Drying step,
A mixing step of dry-mixing the powdery composite particles and the electrode active material to obtain a particle composite, and
And an electrode manufacturing step of manufacturing an electrode using the particle composite.