Classifications

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  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G51/00—Compounds of cobalt
  • C01G51/40—Complex oxides containing cobalt and at least one other metal element
  • C01G51/42—Complex oxides containing cobalt and at least one other metal element containing alkali metals, e.g. LiCoO2
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  • C01G51/00—Compounds of cobalt
  • C01G51/40—Complex oxides containing cobalt and at least one other metal element
  • C01G51/42—Complex oxides containing cobalt and at least one other metal element containing alkali metals, e.g. LiCoO2
  • C01G51/44—Complex oxides containing cobalt and at least one other metal element containing alkali metals, e.g. LiCoO2 containing manganese
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  • C01G53/40—Complex oxides containing nickel and at least one other metal element
  • C01G53/42—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2
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  • C01G53/00—Compounds of nickel
  • C01G53/40—Complex oxides containing nickel and at least one other metal element
  • C01G53/42—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2
  • C01G53/44—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese
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  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G55/00—Compounds of ruthenium, rhodium, palladium, osmium, iridium, or platinum
  • C01G55/002—Compounds containing ruthenium, rhodium, palladium, osmium, iridium or platinum, with or without oxygen or hydrogen, and containing two or more other elements
• • H—ELECTRICITY
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  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/04—Processes of manufacture in general
• • H—ELECTRICITY
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  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
  • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
  • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/30—Particle morphology extending in three dimensions
  • C01P2004/32—Spheres
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  • C01P2004/00—Particle morphology
  • C01P2004/51—Particles with a specific particle size distribution
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  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
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  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/40—Electric properties
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/058—Construction or manufacture
  • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the present invention relates to a method for producing a nonaqueous electrolyte secondary battery and a positive electrode active material used for the secondary battery.
• lithium batteries especially rechargeable lithium secondary batteries
• lithium secondary batteries using lithium metal for the negative electrode had great expectations as high energy density batteries.
• dendritic lithium (dendrites) generated during charging grows as the battery is charged and discharged, causing problems such as internal short-circuiting of the battery and abnormal temperature rise of the battery.
• the alloy which was refined due to charge and discharge, penetrated the separator, and eventually caused an internal short circuit, so that practicality was difficult.
• lithium secondary batteries using carbon for the negative electrode and a transition metal compound containing lithium for the positive electrode have become the mainstream.
• charge and discharge are performed by inserting and extracting lithium ions into and from the carbon of the negative electrode, so that a dendrite does not occur during charging, and a battery with good cycle characteristics and excellent safety is provided. It is becoming possible.
• Li CoO 2 Li CoO 2 , Li
• L i C o O cell using 2 is already commercialized as a positive electrode active material, also, L i as a positive electrode active material N i 0 2 is low cost compared to L i CoO 2, since a high-capacity, research and development are actively conducted.
• JP-A-8-138672 discloses that lithium hydroxide and a nickel salt are mixed in ethanol, dried, granulated, and calcined at a temperature of 350 to 500 ° C. ⁇ 850 L i N i 0 2 a manufacturing technology as Li positive electrode active material by the heating ° C shall have been disclosed.
• US Pat. No. 5,264,201 or JP-A-6-342657 discloses nickel oxide and nickel hydroxide or Fe, Co, Cr, T i,
• Japanese Patent Application Laid-Open No. 8-85861 discloses that a lithium compound and a nickel compound are mixed, fired at a temperature of 600 to 900 ° C, and then fired at a temperature of 400 to 700 ° C. techniques for producing i O 2 is disclosed.
• Japanese Patent Application Laid-Open No. 8-153513 discloses that a positive electrode is prepared by mixing a lithium compound with a metal salt, a metal oxide or a metal hydroxide and heat-treating the mixture at a temperature of 600 to 100 ° C. A method for synthesizing an active material is disclosed.
• a lithium compound metal oxide is synthesized using a lithium compound. If greater, for example, D s . There particles of greater than 5 Li Chiu ⁇ compound, D 9. Of lithium compound larger than 90 m or particle size of 100 Lithium if particles of lithium compound are present The contact area between the compound and the metal carbonate, metal oxide or metal hydroxide mixed with the compound is reduced, and as a result, the lithium salt is biased in the obtained positive electrode active material and the synthesis reaction is sufficiently performed.
• D Sfl and D s were the values when the cumulative volume of the small particles reached 50% and 90%, respectively). Indicate the particle size).
• the segregation of lithium in the positive electrode active material partially generates a lithium composite metal oxide having a smaller amount of lithium than that of the stoichiometric composition, and the partially generated amount of lithium is changed to a stoichiometric composition.
• Lithium composite metal oxides with less charge are said to undergo repeated charge / discharge, disrupting the layer structure of the polycrystal, preventing the diffusion of lithium ions, and deteriorating the charge / discharge cycle characteristics of non-aqueous electrolyte secondary batteries. There was a problem.
• a lithium compound and other raw materials are mixed in a solvent such as ethanol to form a slurry, and a positive electrode active material is synthesized while the raw materials are in sufficient contact with each other.
• a solvent such as ethanol
• a positive electrode active material is synthesized while the raw materials are in sufficient contact with each other.
• the present invention provides a positive electrode active material for a non-aqueous electrolyte secondary battery, which has a chemical formula Li x MO 2 (0.50 ⁇ x ⁇ 1.10, M is one or more types)
• a lithium composite metal oxide represented by the following transition metal, IIA metal or IIIA metal the lithium composite metal oxide has a chemical formula of M, (OH) 2 (0.6 ⁇ y ⁇ 1, M is a metal hydroxide represented by one or more transition metals, IIA metal or IIIA metal), chemical formula ⁇ , ⁇ (0.6 ⁇ y ⁇ 1.
• M is one or more transition metal, IIA metal or IIIA Metal) and at least one of metal carbonates represented by the chemical formulas M and CO J (0.6 ⁇ y ⁇ 1, where M is one or more transition metals, IIA metals or IIIA metals) and, D 5. Is 5-50 / m, D 90 W
• 4 is 90 zm or less, and is mixed with a lithium compound having no particles having a particle diameter of 100 tm or more, which is baked and then pulverized.
• the discharge capacity per active material weight of the positive electrode active material can be increased, and the cycle characteristics can be improved.
• the configuration of the present invention will be described in more detail below.
• the present invention provides at least one of a hydroxide, an oxide and a carbonate of at least one metal selected from the group consisting of transition metals, IIA metals and IIIA metals, and D s .
• D 9 Is mixed with a lithium compound not containing particles having a particle size of 90 tm or less and a particle size of 100 tm or more, and then calcined in a temperature range of preferably 700 to 1 000 ° C., preferably for 2 to 30 hours. This is to produce a positive electrode active material by pulverization.
• the positive electrode active material is a lithium composite metal oxide represented by the chemical formula i x MO 2 (0.50 ⁇ x ⁇ 1.10, M is one or more transition metals, IIA metals or IIIA metals). Is what you do.
• M is one or more transition metals, IIA metal or IIIA metal) metal hydroxide represented by the chemical formula M y O (0. 6 ⁇ y ⁇ 1, metal oxides or formula is the table in Micromax 1 or more transition metals, II Alpha metal or IIIA metal) M y CO 3 (0. 6 ⁇ y ⁇ 1, M is a transition of one or more Metal, IIA metal or IIIA metal).
• lithium compound one or more of lithium hydroxide, lithium carbonate and lithium nitrate are preferable.
• the metal hydroxide, metal oxide, and metal carbonate particles preferably form spherical or elliptical secondary particles.
• metal hydroxide examples include cobalt hydroxide or nickel hydroxide alone or a mixture thereof, or a hydroxide containing cobalt and nickel, manganese hydroxide alone, or cobalt hydroxide or nickel hydroxide. And mixtures of manganese hydroxide or hydroxy containing cobalt, nickel and manganese Chloride, aluminum hydroxide alone or a mixture of cobalt hydroxide, nickel hydroxide and aluminum hydroxide, or a hydroxide containing cobalt, nickel and aluminum hydroxide.
• lithium composite metal oxide L i x MO 2 L i C o0 2, L i N i O 2, L i N i,. X C o x O 2, L i N i,. X. Y .. C o X M n y O 2, L i n i, x y C o x AI, 0 2, L i n i, -. x Mn x 0 2, L i n i, x AI x O 2, L i M n O 2, L i Mn 2 0 4 (x ⁇ 1, y ⁇ l, x + y ⁇ 1) and the like are preferable.
• the lithium compound D 5 In preparing the lithium composite metal oxide, the lithium compound D 5 . Is greater than 50 m or D s . Is larger than 90 Atm or particles with a diameter of 1 ⁇ ⁇ ⁇ or more are present, the contact area between the lithium compound and the metal carbonate, metal oxide or metal hydroxide is reduced, and In addition, lithium salt is biased, and the synthetic reaction does not proceed sufficiently, and the capacity per active material weight decreases. In addition, due to the bias of lithium in the active material, a lithium composite metal oxide having a smaller amount of lithium than the stoichiometric composition is partially generated, and the layer structure of the crystal collapses due to repeated charge and discharge. This impedes lithium ion diffusion and degrades cycle characteristics.
• the powder flowability is poor for Li is not sufficiently dispersed when mixing and stirring the raw materials, causing the lithium salt is segregated in the active material,
• the lithium compound as a raw material has a D 5 of 5 to 5 Oim, and a D 5 of 5 to 30 / im. preferable.
• lithium hydroxide is obtained by reacting lithium carbonate with calcium hydroxide or lithium sulfate and barium hydroxide to form a white precipitate, which is obtained as lithium hydroxide monohydrate.
• a white precipitate which is obtained as lithium hydroxide monohydrate.
• Can be. Work in this way Manufactured by lithium hydroxide monohydrate, D 5.
• the lithium hydroxide monohydrate is used as it is in the production of a lithium composite metal oxide, the discharge capacity and cycle characteristics are reduced for the above-mentioned reasons.
• D s for the lithium hydroxide monohydrate used for the production of the lithium composite metal oxide, pulverization and classification steps were added, and D s . There 5 ⁇ 50 tm, D s. It is preferable that the particles be used in a state in which particles having a diameter of 90 xm or less and a diameter of 10 O tm or more do not exist. And D s . There 5 ⁇ 30 tm, D 3. Most preferably, there is no particle having a particle diameter of 60 tm or less and a diameter of 90 im or more.
• Lithium hydroxide is obtained by heating and dehydrating lithium hydroxide monohydrate, but it is easy to hydrate and changes its weight, which makes storage management difficult. It is desirable to use the lithium hydroxide prepared as described above.
• Lithium carbonate is synthesized by ore extraction and brackish water recovery, but mass-produced lithium carbonate is mainly synthesized by ore sulfuric acid. After calcination and pulverization of ore, sulfuric acid is added and heated, extracted with water to form lithium sulfate, and then reacted with soda lime to obtain lithium carbonate as a white precipitate. Lithium carbonate produced in this way is generally D 5 . There Since the 20 ⁇ 3 Oiim, but sufficient effect be directly used Re this is obtained, further addition of pulverizing and classifying steps Teri s. It is more effective when used in a state where particles having a diameter of 5 to 15 m, a D3fl of 50 tm or less, and a diameter of 100 m or more do not exist.
• the sintering temperature is less than 700 ° C or the sintering time is less than 2 hours, the synthesis reaction of the lithium composite metal oxide will be insufficient, and some will not be reacted. However, the capacity per weight decreases. In addition, since the crystallization of the lithium composite metal oxide becomes insufficient, repeated charge / discharge disrupts the layer structure of the crystal, which hinders diffusion of lithium ions and causes a reduction in discharge capacity.
• the firing temperature is higher than 1 000 ° C or the firing time is longer than 30 hours, lithium and lithium are added to the metal part of the lithium composite metal oxide.
• the crystal structure changes from a hexagonal structure to a rock-salt structure, preventing the diffusion of lithium ions during charge and discharge, causing a reduction in discharge capacity.
• the firing temperature is preferably from 700 to 100 ° C.
• the firing time is preferably from 2 to 30 hours.
• the present invention relates to a method for producing a positive electrode active material, and does not limit the negative electrode in any way, but when carbon is used for the negative electrode as described in the examples, it has a high energy density and excellent characteristics.
• a non-aqueous electrolyte secondary battery having high safety can be obtained.
• the use of graphite is preferable because a high voltage can be obtained.
• non-aqueous electrolyte in the present invention is not limited at all, and a non-aqueous electrolyte, a solid electrolyte, or both may be used.
• a non-aqueous electrolyte, a solid electrolyte, or both may be used.
• a liquid it is composed of a solvent and a lithium salt dissolved in the solvent.
• Non-aqueous solvents include, for example, cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), getyl carbonate (DEC), Acyclic carbonates such as ethyl methyl carbonate (EMC); aliphatic carboxylic esters such as methyl formate, methyl acetate, methyl propionate, and ethyl propionate; and T-lactones such as carboxylactone; , 2-Dimethoxyethane (DME), 1,2-Jetoxetane (DEE), Ethoxymethoxetane (EME), etc., cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, etc. And non-protonic organic solvents. These solvents may be used alone or in combination of two or more. .
• cyclic carbonates such as ethylene carbonate (EC), propylene carbonate (PC
• a mixed system of a cyclic carbonate and an acyclic carbonate or a mixed system of a cyclic carbonate and an acyclic carbonate and an aliphatic carboxylic acid ester is used. preferable.
• lithium salt dissolved in those solvents for example, L i CI 0 4, L i BF 4, L i PF 6, L i CF 3 S0 3, L i CF 3 C0 2, L i (CF 3 S0 2) 2, L i a s F 6 , L i N (CF 3 S0 2) can be exemplified 2 like, can be used alone or in combination of two or more in the electrolyte solution or the like to use them, in particular it is more preferred to include L i PF 6.
• Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes.
• Well known inorganic solid electrolytes include Li nitrides, halides, and oxyacid salts.
• L i 3 N, L i and L i 5 NI 2 L i 3 N— L i I — L i OH, L i 4 S i 0 4 , L i 4 S i 0 4 -L i I one L i OH, x L i 3 P0 4 - (1 - x) L i 4 S i 0 4, L i 2 S i S 3, it is effective and phosphorus sulfide compounds.
• Organic solid electrolytes include, for example, polyethylene oxide, polypropylene oxide, polyphosphazene, polyaziridine, polyethylene sulfide, polyvinyl alcohol, polyvinylidene fluoride, polyhexafluoropropylene, and derivatives, mixtures, and composites thereof. Polymer matrix materials such as these are effective. In particular, a copolymer of vinylidene fluoride and hexafluene-propylene oxide—a mixture of polyvinylidene fluoride and polyethylene oxalate is preferred.
• the figure is a cross-sectional view of a cylindrical lithium secondary battery using a positive electrode active material obtained according to an example of the present invention.
• the figure shows a cross-sectional view of a cylindrical lithium secondary battery using the positive electrode active material obtained in the example.
• 1 is a battery case with a stainless steel plate resistant to organic electrolyte
• 2 is a sealing plate provided with a safety valve
• 3 is an insulating packing
• 4 is a group of electrodes housed in the battery case 1
• Reference numeral 8 denotes a positive electrode lead drawn from the positive electrode 5 and connected to the sealing plate 2
• reference numeral 9 denotes a negative electrode lead drawn from the negative electrode 6 and connected to the bottom of the battery case 1
• reference numeral 10 denotes an insulating ring. It is provided at the top and bottom respectively.
• the positive electrode 5 is formed as follows. 100 parts by weight of a lithium composite metal oxide as a positive electrode active material was mixed with 3 parts by weight of acetylene black, and an N-methylpyrrolidone solution in which 4 parts by weight of polyvinylidene fluoride was dissolved in the mixture was used as a binder. And knead it into a paste. This paste-like kneaded material is coated on both sides of a 0.020 mm thick aluminum foil, dried, and then rolled to form an electrode plate having a thickness of 0.130 mm, a width of 35 mm and a length of 270 mm.
• the negative electrode 6 is formed as follows. Using mesophase graphite graphitized t ⁇ so-called mesophase graphite, 100 parts by weight of this mesophase graphite and 3 parts by weight of styrene Z butadiene rubber are mixed as a binder, and an aqueous solution of sodium ruboxymethyl cellulose is used. In addition, it is kneaded to form a paste. This paste-like kneaded material is coated on both sides of copper foil, dried, and rolled to make a 0.20 mm thick, 37 mm wide, 280 mm long electrode plate.
• a positive electrode lead 8 made of aluminum is attached to the positive electrode 5, and a negative electrode lead 9 made of nickel is attached to the negative electrode 6 .
• the positive electrode 5 and the negative electrode 6 have a thickness of 0.025 mm, a width of 45 mm, and a length of 740 mm. It is laminated via a polyethylene separator 7 and spirally wound into an electrode group 4, and delivered to a battery case 1 with a diameter of 13.8 mm and a height of 50 mm.
• the electrolyte was prepared by dissolving 1 mol of lithium hexafluorophosphate in a solvent obtained by mixing ethylene carbonate and ethyl methyl carbonate in a volume ratio of 20:80. I have.
• Nickel sulfate and cobalt sulfate are dissolved in water so that the molar ratio of C 0 to Ni becomes 20% to form a nickel sulfate-cobalt mixed solution.
• a sodium hydroxide solution is added to the cobalt mixed solution and coprecipitated to obtain a nickel-cobalt hydroxide.
• the obtained nickel-cobalt hydroxide was washed in water, dried at 8 CTC to obtain a powder, and formed into a powder of nickel-cobalt hydroxide (Ni) having a secondary particle size similar to spherical or elliptical spherical. 8 Co. 2 (OH) 2 ) can be produced.
• the nickel-cobalt hydroxide prepared in this manner was designated as D s .
• TC temperature in an oxygen atmosphere 70
• TC temperature in an oxygen atmosphere 70
• the particle size distribution was measured using a laser-type particle size distribution analyzer (HOL IBA LA-910), and isopropyl alcohol was used as the dispersion medium.
• lithium composite metal oxide prepared by the (L i N i 08 Co fl 2 0 2) and Example 1 in Table 1.
• Example 2 If 88 01 In Table 1, 0 5. Is 5 / ⁇ 111, D 9. Are 2 O Contact Keru Example 3 in Table 1. For tm I do.
• Example 1 the case where the firing temperature was 600 ° C, 900 ° C, 1 000 ° C, 1 050 e C, and Example 4-7 in Table 1, respectively.
• Example 1 the cases where the firing time was set to 1 hour, 2 hours, 30 hours, and 40 hours in Example 1 are referred to as Examples 8 to 11 in Table 1, respectively.
• Nickel was prepared in the same manner as in Example 1 - cobalt hydroxide to (N i 0.8 C 0. 2 ( OH) 2), D 5. Is 60 tm, D 9 () is 88 ⁇ , and the particle size is 100; Co) is mixed so that the molar ratio becomes 1 to 1, and calcined in an oxygen atmosphere at a temperature of 700 ° C. for 20 hours, and then pulverized to obtain Li N i. 8 Co. 2 0 2 and Comparative Example ⁇ in Table 1.
• Comparative Example 1 Ds. But 50 m, D 30 is at 98 / xm, the case where the particle diameter with 1 00 lithium hydroxide monohydrate m or more particles are not present in Comparative Example 2 in Table 1.
• Comparative Example 1 uses lithium hydroxide monohydrate having a particle size of 88 ⁇ m and particles having a particle diameter of 100 or more in a volume ratio of 3% of the whole.
• a charge / discharge test was performed under the following conditions.
• the battery is charged at a constant current and constant voltage of 4.2 V for 2 hours, that is, a constant current of 420 mA is charged until the battery voltage reaches 4.2 V, and then a total of 2 is charged with 4.2 V loaded.
• a constant limiting resistor was set so that the current value attenuated so that the battery would charge over time.
• the discharge was a constant current discharge of 61 mA, and the discharge end voltage was 3.0 V.
• Example 2 and Comparative Examples 1 to 3 D 5 of lithium hydroxide monohydrate was obtained. Is greater than 50 m or D 5 in lithium hydroxide monohydrate. Is 50 m, but D s . It can be seen that both the specific capacity of the active material and the cycle characteristics are reduced when the particle size is larger than 90 or when the particle size is 100 jam or more. Here, the capacity per active material weight decreases because the specific surface area of lithium hydroxide monohydrate decreases and the contact area between lithium hydroxide monohydrate and nickel-cobalt hydroxide decreases. Therefore, it is thought that the lithium salt was biased in the active material and the synthesis reaction did not proceed sufficiently.
• the decrease in cycle characteristics is attributed to the segregation of lithium, which partially produces a lithium composite metal oxide with a smaller amount of lithium than the stoichiometric composition, and repeats charging and discharging to form crystals. This is probably due to the collapse of the layer structure.
• Example 1 and Examples 4 to 7 in the temperature range where the sintering temperature was 600 to 150, the cycle characteristics were superior to those of the comparative example, and 700 to 100. It can be seen that the discharge capacity is almost the same in the temperature range of 0 ° C.
• the firing capacity was 1 to 40 hours
• the discharge capacity or cycle characteristics were better than those of the comparative example
• the discharge capacity was almost 2 to 30 hours. It turns out that they are the same.
• Example I Example 7 and Example 11
• the specific capacity of the active material and the cycle characteristics are reduced. It can be seen that both have decreased.
• the cycle characteristics are better than the comparative example ing.
• the capacity per unit weight of the active material is reduced because the lithium composite metal oxide has a structure in which the metal part contains lithium and the lithium part contains metal, and the crystal structure changes from a hexagonal structure to a rock salt. The reason for this is that the capacity changes to the end of the cycle (300 mAh) due to the low initial capacity due to the change to the die structure, preventing diffusion of lithium ions during charge and discharge, and the decrease in cycle characteristics. This seems to be due to the early
• the firing temperature is preferably from 700 to 100 ° C.
• the firing time is preferably from 2 to 30 hours.
• Example 12 The lithium composite metal oxide thus produced is referred to as Example 12 in Table 2.
• Example 12 D s was used instead of lithium hydroxide to be mixed. There 3 0 f m. D M is at 50 m, and particle size of the Example 1 3 in Table 2 when using the 1 0 0 ⁇ lithium carbonate acid m or more of the particles does not exist as the raw material.
• Example 12 was used instead of lithium hydroxide to be mixed. Is 5 Mm, D s .
• Example 14 in Table 2 is a case in which lithium carbonate having a particle size of 30 ⁇ and a particle size of 100 tm or more is used as a raw material.
• nickel sulfate and cobalt sulfate are dissolved in water so that the molar ratio of C 0 to Ni becomes 20% to form a nickel-cobalt sulfate mixed solution.
• a nickel-cobalt carbonate is obtained by co-precipitating a sodium carbonate solution.
• the resulting nickel - cobalt carbonate is washed with water, 80 when ° and dried in C to powdered nickel to form a secondary particle diameter Ruishi spherical or oval-spherical - cobalt Bok carbonate (N i 08 C o 2 CO 3 ) can be produced.
• Nickel-cobalt carbonate prepared in this way and D s . Is 3 0 tm, D 9.
• Example 15 Is mixed with lithium hydroxide monohydrate having a particle diameter of 50 m and a particle diameter of not less than 100 tm so that the molar ratio of i Z (N i + C 0) is 1 Z1, Baking in an oxygen atmosphere at a temperature of 700 ° C for 20 hours, followed by pulverization to obtain L i N i. 8 C 0. 2 0 2 to produce.
• the lithium composite metal oxide thus produced is referred to as Example 15 in Table 2.
• Example 1 5 when the same nickel cobaltous carbonate produced by the method (N i C 0 02 CO 3 ) was heated at a temperature of 500 ° C, nickel-cobalt Bokusan product (N i, 8 Co 0 ? O) The powder of the nickel cobaltous oxide, the double Tsu as in the Kell-cobalt carbonate, so to form a secondary particle child diameter Ruishi spherical or oval-spherical, the nickel - cobalt oxide and D 5. But 30 ⁇ , D 9. Is mixed with lithium hydroxide monohydrate having a particle size of 50 ⁇ m and no particles having a particle size of 00 m or more so that the molar ratio of LiZ (Ni + Co) becomes 1Z1. Baking for 20 hours at a temperature of 700 ° C. in an oxygen atmosphere and then pulverizing LiN i. 8 Co. Make z O 2 . The compound prepared in this step is referred to as Example 16 in Table 2.
• the nickel cobaltous hydroxide (0 N i 08 C 0 2 (OH) 2.) which was prepared in the same manner as in Example 1, by heating the nickel - cobalt oxide (N i , 8 Co 02 O).
• the nickel-cobalt oxide powder thus produced has a secondary particle diameter similar to a spherical or elliptical spherical shape, as in the case of the nickel-cobalt hydroxide.
• But 30 tm, D 3. Is mixed with lithium hydroxide monohydrate having a particle diameter of 50 and having no particles having a particle diameter of 100 m or more so that the molar ratio of LiZ (Ni + Co) becomes 1 Z1. It is baked in an atmosphere at a temperature of 700 ° C. for 20 hours, and then pulverized to obtain Li N i. 8 Co. Prepare a z 0 2.
• the lithium composite metal oxide thus produced is referred to as Example 17 in Table 2.
• D se is 50 im or less of the lithium compound
• D M is 90 tm or less
• the particle diameter is present 1 00 tm or more particles, the discharge capacity is high in regardless of the raw material species, charge It can be seen that an active material that can withstand a discharge cycle can be generated.
• D s is 5 to 30 tm and D s . Is more effective when the particle size is 50 jam or less and there is no particle having a particle size of 100 / m or more.
• a metal hydroxide prepared by changing the metal type and ratio of the metal sulfate in the same manner as in Example 1, Ri 5.
• Ri 5 There 30 £ 01, D 9.
• Is selected from the group of Li / M (M is Ni, Co, Mn, AI) with a lithium hydroxide monohydrate having a particle size of 50 / im and a particle size of 100 jm or more. molar ratio of 1 or more) are mixed so that the 1/1, in an oxygen atmosphere and baked at a temperature of 700 ° C 20 h, then lithium mixed metal oxide by milling i M0 2 (M Produces at least one selected from the group consisting of Ni, Co, Mn, and AI).
• the lithium composite metal oxides thus produced are referred to as Examples 18 to 26 in Table 3.
• D s of the raw material Lichiumyi Dangdang. Cathode active but. 5 to 50 m, with D 90 of 90 tm or less, and if the particle diameter is present 1 00 im or more particles, that regardless of the raw material species, high discharge capacity can withstand charge-discharge cycle Can produce substances.
• lithium hydroxide monohydrate having a particle size of 50 m and a particle size of 100 m or more
• i ZM M is selected from the group of Ni, Co, M n, and AI 2 the molar ratio of the types or more
• L i M0 2 M by grinding Ni, Co, Mn, two or more selected from the group of AI.
• the lithium composite metal oxide thus produced is referred to as Examples 27 to 33 in Table 4.
• D $ of the Lithi dagger There 5 ⁇ 50 Atm, D 3. Is 90 / xm or less, and if there is no particle with a particle size of 10 ⁇ or more, a positive electrode active material that has a high discharge capacity and can withstand a charge-discharge cycle can be generated regardless of the type of the raw material. . From the above, in the preparation of the positive electrode active material, the metal carbonate and the metal oxide or metal hydroxide, and D $. There 5 ⁇ 5 0 ⁇ m, D s. Is used as the raw material of the positive electrode active material, and a non-aqueous electrolyte secondary battery having excellent discharge capacity and cycle characteristics is used. It is possible to provide a lithium secondary battery which is a battery. Table 4
• the lithium double if metal oxides, L i C 0 O 2, and i N i O 2 'L i N i C o x O 2, And i N i, - x -. . Y C o X M n y O 2, L i N i, x y C o x AI y 0 2, L i N i preparative x Mn x O 2, L i N i
• -x AI x O 2 has been described, but it is represented by the chemical formula i x MO 2 (0.50 ⁇ x ⁇ 1.10, M is one or more transition metals, IIA metals or IIIA metals). Similar effects can be obtained in the case of the lithium composite metal oxide.
• the metal hydroxide used as a raw material of the lithium composite metal oxide is represented by the chemical formula M, (OH) 2 (0.6 ⁇ y ⁇ l, where M is one or more transition metals, IIA metals or IIIA metals).
• the compounds represented by the chemical formulas M and O (0.6 ⁇ y ⁇ ⁇ , where M is one or more transition metals, IIA metals or IIIA metals) as the metal oxides, and the metal carbonates as the metal carbonates chemical formula M y C0 3 (0. 6 ⁇ y ⁇ 1, M is one or more transition metals, IIA metal or IIIA metal) is effective those represented by.
• the evaluation was performed using a cylindrical lithium secondary battery, but the same effect can be obtained even when the battery shape is different, such as a prismatic type.
• the present invention is implemented in the form described above, and includes at least one of a metal carbonate, a metal oxide, and a metal hydroxide, and D 5 . There 5 In 50 m, D 3. Is 90 / m or less, and a lithium composite metal oxide prepared from a lithium compound having no particles having a particle diameter of 100 Atm or more as a raw material is used as a positive electrode active material, thereby increasing the contact area between the raw materials, It is possible to suppress segregation of the lithium salt that is likely to occur during synthesis, and to improve the discharge capacity and cycle characteristics of the nonaqueous electrolyte secondary battery.

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