WO2018123951A1 - 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 - Google Patents
非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 Download PDFInfo
- Publication number
- WO2018123951A1 WO2018123951A1 PCT/JP2017/046391 JP2017046391W WO2018123951A1 WO 2018123951 A1 WO2018123951 A1 WO 2018123951A1 JP 2017046391 W JP2017046391 W JP 2017046391W WO 2018123951 A1 WO2018123951 A1 WO 2018123951A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- niobium
- lithium
- positive electrode
- active material
- electrode active
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/40—Nickelates
- C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G33/00—Compounds of niobium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/006—Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/40—Nickelates
- C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
- C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/40—Nickelates
- C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
- C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
- C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
-
- 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
- H01M10/052—Li-accumulators
-
- 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
- H01M10/052—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
- H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
-
- 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
- H01M4/362—Composites
-
- 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
- H01M4/50—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
-
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
- C01P2002/54—Solid solutions containing elements as dopants one element only
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/60—Compounds characterised by their crystallite size
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
- C01P2002/85—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by XPS, EDX or EDAX data
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
-
- 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
- C01P2004/45—Aggregated particles or particles with an intergrown morphology
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- 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
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- 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
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
-
- 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
Definitions
- the present invention relates to a positive electrode active material for a non-aqueous electrolyte secondary battery, a manufacturing method thereof, and a non-aqueous electrolyte secondary battery.
- non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries as secondary batteries that satisfy such requirements.
- a non-aqueous electrolyte secondary battery includes a negative electrode, a positive electrode, a non-aqueous electrolyte, and the like, and a material capable of desorbing and inserting lithium is used as an active material for the negative electrode and the positive electrode. Further, non-aqueous electrolyte secondary batteries are required to have higher thermal stability in addition to high battery capacity and durability.
- non-aqueous electrolyte secondary batteries using a layered or spinel type lithium metal composite oxide as a positive electrode active material, Since a high voltage of 4V class can be obtained, practical use is progressing as a battery having a high energy density.
- lithium metal composite oxide used for the positive electrode active material lithium cobalt composite oxide (LiCoO 2 ) that is currently relatively easy to synthesize, or lithium nickel composite oxide (LiNiO 2 ) using nickel that is cheaper than cobalt. ), Lithium manganese composite oxide (LiMn 2 O 4 ) using manganese, lithium nickel manganese composite oxide (LiNi 0.5 Mn 0.5 O 2 ), and the like have been proposed.
- lithium nickel cobalt manganese composite oxide (LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) having excellent thermal stability and high capacity has attracted attention.
- the lithium nickel cobalt manganese composite oxide is a layered compound similar to lithium cobalt composite oxide and lithium nickel composite oxide, and basically has a composition ratio of 1: 1, nickel, cobalt and manganese at the transition metal site. 1 is included.
- the lithium metal composite oxide has a high energy density as described above.
- a non-aqueous electrolyte is used as a battery material, higher thermal stability is required.
- a lithium ion secondary battery is known to cause thermal runaway by releasing oxygen from the crystal and reacting with an electrolyte when heat is applied in a charged state.
- the thermal stability during overcharge for example, a different element is added to the positive electrode active material to stabilize the crystal structure, or the surface of the positive electrode active material is made of SiO 2 , Al 2 O 3 , ZrO 2.
- a method of coating with an oxide such as has been proposed.
- the initial battery capacity is greatly reduced, and it is difficult to achieve both battery capacity improvement and thermal stability.
- the manufacturing process is complicated or the scale-up is difficult, and therefore, industrial scale production is often difficult.
- a different metal such as tungsten or niobium is added to the lithium metal composite oxide.
- Patent Document 1 includes a general formula: Li a Ni 1-xyz Co x M y Nb z O b (where M is one or more elements selected from the group consisting of Mn, Fe and Al, 1 ⁇ a ⁇ 1.1, 0.1 ⁇ x ⁇ 0.3, 0 ⁇ y ⁇ 0.1, 0.01 ⁇ z ⁇ 0.05, 2 ⁇ b ⁇ 2.2)
- M is one or more elements selected from the group consisting of Mn, Fe and Al
- 1 is one or more elements selected from the group consisting of Mn, Fe and Al, 1 ⁇ a ⁇ 1.1, 0.1 ⁇ x ⁇ 0.3, 0 ⁇ y ⁇ 0.1, 0.01 ⁇ z ⁇ 0.05, 2 ⁇ b ⁇ 2.2
- a positive electrode active material for a non-aqueous secondary battery comprising a composition composed of at least one compound composed of cobalt, element M, niobium and oxygen.
- Patent Document 2 discloses a mixing step of mixing a nickel-containing hydroxide, a lithium compound, and a niobium compound having an average particle size of 0.1 to 10 ⁇ m to obtain a lithium mixture, and the lithium mixture in an oxidizing atmosphere for 700 to
- Positive electrode active for a non-aqueous electrolyte secondary battery comprising a lithium transition metal composite oxide composed of polycrystalline particles obtained by a manufacturing method including a firing step of firing at 840 ° C. to obtain a lithium transition metal composite oxide
- the positive electrode active material is a positive electrode active material having a porous structure, a specific surface area of 0.9 to 3.0 m 2 / g, and an alkali metal content other than lithium of 20 mass ppm or less. It is described. According to Patent Document 2, it is said that a positive electrode active material having both high thermal stability and high charge / discharge capacity and excellent cycle characteristics can be obtained.
- Patent Document 3 a niobium salt solution and an acid are simultaneously added to a nickel-containing hydroxide slurry, and the pH of the slurry is controlled to be constant within a range of 7 to 11 on a 25 ° C. basis.
- a non-aqueous electrolyte comprising a lithium transition metal composite oxide composed of particles having a polycrystalline structure, obtained by a production method including a firing step of firing at 700 to 830 ° C.
- a positive electrode active material for a secondary battery has been proposed. It is described that this positive electrode active material has a porous structure and has a specific surface area of 2.0 to 7.0 m 2 / g. According to Patent Document 3, a non-aqueous electrolyte secondary battery having high safety, battery capacity, and excellent cycle characteristics can be obtained by using this positive electrode active material.
- Patent Document 4 discloses a positive electrode active material for a non-aqueous electrolyte secondary battery having at least a layered lithium transition metal composite oxide, wherein the lithium transition metal composite oxide includes primary particles and aggregates thereof. It exists in the form of particles comprising one or both of secondary particles, the primary particles have an aspect ratio of 1 to 1.8, and at least the surface of the particles is composed of molybdenum, vanadium, tungsten, boron, and fluorine.
- a positive electrode active material for a non-aqueous electrolyte secondary battery having a compound having at least one selected from the group has been proposed. According to Patent Document 4, conductivity is improved by having a compound having at least one selected from the group consisting of molybdenum, vanadium, tungsten, boron and fluorine on the surface of the particles.
- Patent Document 5 includes, as a main component, a lithium transition metal compound having a function capable of inserting and removing lithium ions, and the main component material contains at least one element selected from B and Bi. And a lithium transition metal compound for a lithium secondary battery positive electrode material obtained by adding a compound containing at least one element selected from Mo, W, Nb, Ta, and Re together and then firing the compound. Powders have been proposed. According to Patent Document 5, a lithium transition metal compound powder composed of fine particles in which grain growth and sintering are suppressed is obtained by firing after adding additive elements in combination, and the rate and output characteristics are high. It is said that a lithium-containing transition metal compound powder that is improved and easy to handle and prepare an electrode can be obtained.
- Patent Document 6 discloses that the general formula Li a Ni 1-xy Co x M1 y W z M 2 wO 2 (1.0 ⁇ a ⁇ 1.5, 0 ⁇ x ⁇ 0.5, 0 ⁇ y ⁇ 0.5, 0.002 ⁇ z ⁇ 0.03, 0 ⁇ w ⁇ 0.02, 0 ⁇ x + y ⁇ 0.7, M1 is at least one selected from the group consisting of Mn and Al, M2 is Zr, A non-aqueous electrolyte secondary comprising a lithium transition metal composite oxide represented by at least one selected from the group consisting of Ti, Mg, Ta, Nb, and Mo) and a boron compound containing at least a boron element and an oxygen element A positive electrode composition for a battery has been proposed. According to Patent Document 6, in a positive electrode composition using a lithium transition metal composite oxide, by using a positive electrode composition containing a lithium transition metal composite oxide containing nickel and tungsten and a specific boron compound
- the present invention has been made in view of these circumstances, and is a positive electrode active material from which a nonaqueous electrolyte secondary battery can be obtained that has both high battery capacity and durability and thermal stability during overcharging at a high level. Is intended to provide. Moreover, an object of this invention is to provide the method which can manufacture such a positive electrode active material easily in industrial scale production.
- the present inventor has improved the battery characteristics by adding a specific amount of niobium to a lithium nickel manganese composite oxide containing a specific amount of manganese.
- the present invention has been completed by obtaining the knowledge that it is possible to achieve both high thermal stability by suppressing oxygen release during charging.
- a positive electrode active material for a non-aqueous electrolyte secondary battery including a lithium nickel manganese composite oxide composed of secondary particles in which a plurality of primary particles are aggregated and a lithium niobium compound.
- the cathode active material of the general formula (1) Li d Ni 1 -a-b-c Mn a M b Nb c O 2 + ⁇
- M is Co, W, Mo , V, Mg, Ca, Al, Ti, Cr, Zr and Ta, 0.03 ⁇ a ⁇ 0.60, 0 ⁇ b ⁇ 0.60, 0.02 ⁇ c ⁇ 0.08, a + b + c ⁇ 1, 0.95 ⁇ d ⁇ 1.20, 0 ⁇ ⁇ ⁇ 0.5)
- the lithium-nickel-manganese composite oxide is a crystallite of (003) plane
- the diameter is 50 nm or more and 130 nm or less, and the lithium niobium compound is formed on the primary particle surface.
- Mashimashi, and a portion of the niobium in the positive electrode active material, a solid solution in the primary particles, the positive electrode active material for a non-aqueous electrolyte secondary battery is provided.
- lithium niobate compound Li 3 NbO 4, LiNbO 3, Li 5 NbO 5, preferably contains one of LiNb 3 O 8 and Li 8 Nb 2 O 9.
- the lithium niobium compound may include an amorphous phase.
- the volume average particle diameter MV of a positive electrode active material is 5 micrometers or more and 20 micrometers or less.
- required by Numerical formula (1) is 0.60 or more and 0.98 or less.
- E 4 ⁇ S / L 2 (wherein S is the projected area of the secondary particles, L is the circumference of the secondary particles, and ⁇ is the circumference)
- a positive electrode active material for a non-aqueous electrolyte secondary battery comprising a lithium nickel manganese composite oxide composed of secondary particles in which a plurality of primary particles are aggregated, and a lithium niobium compound.
- a manufacturing method comprising a general formula (2): Ni 1-ab Mn a Mb (OH) 2 + ⁇ (wherein M is Co, W, Mo, V, Mg, Ca, Al , Ti, Cr, Zr and Ta, represented by 0.03 ⁇ a ⁇ 0.60, 0 ⁇ b ⁇ 0.60, 0 ⁇ ⁇ ⁇ 0.4)
- a niobium mixing step of preparing a lithium niobium mixture containing nickel manganese composite hydroxide particles, a niobium compound, and a lithium compound; and calcining the lithium niobium mixture at 750 ° C. to 1000 ° C.
- lithium nickel Manganese composite Comprising a compound, a lithium niobium compound, a firing step to obtain a positive electrode active material of the general formula (1): Li d Ni 1 -a-b-c Mn a M b Nb c O 2 + ⁇
- M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr and Ta, and 0.03 ⁇ a ⁇ 0. .60, 0 ⁇ b ⁇ 0.60, 0.02 ⁇ c ⁇ 0.08, 0.95 ⁇ d ⁇ 1.20, and 0 ⁇ ⁇ ⁇ 0.5.
- a method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery which is present on the surface of the primary particles and in which a part of niobium in the positive electrode active material is dissolved in the primary particles.
- the niobium mixing step includes a crystallization step of obtaining nickel manganese composite hydroxide particles by crystallization, nickel manganese composite hydroxide particles, a lithium compound, and a niobium compound having an average particle size of 0.01 ⁇ m or more and 10 ⁇ m or less. And a first mixing step of preparing a lithium niobium mixture.
- the niobium compound is preferably at least one of niobic acid and niobium oxide.
- the niobium mixing step is a crystallization step for obtaining nickel manganese composite hydroxide particles by crystallization, and a nickel manganese composite hydroxide particle and water are mixed to form a slurry, and the pH of the slurry is based on a liquid temperature of 25 ° C.
- a second mixing step in which the niobium-coated composite hydroxide particles and the lithium compound are mixed to prepare a lithium niobium mixture.
- the lithium niobium mixture before preparing the lithium niobium mixture, it includes a heat treatment step of heat treating the nickel manganese composite hydroxide particles at a temperature of 105 ° C. or more and 700 ° C. or less, and the niobium mixing step includes nickel manganese composite water obtained by heat treatment.
- a lithium niobium mixture containing at least one of oxide particles and nickel manganese composite oxide particles, a niobium compound, and a lithium compound may be prepared.
- a nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte, and including the positive electrode active material for a nonaqueous electrolyte secondary battery in the positive electrode.
- the positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention as a positive electrode, a non-aqueous secondary battery that achieves both high battery capacity and excellent durability and thermal stability during overcharge at a high level is provided. can get.
- the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention can be easily implemented even in industrial scale production, and can be said to have extremely high industrial value.
- FIG. 1A to FIG. 1C are schematic views showing an example of the positive electrode active material of this embodiment.
- FIG. 2 is a diagram illustrating an example of a method for producing a positive electrode active material according to the present embodiment.
- FIG. 3 is a diagram illustrating an example of a method for producing a positive electrode active material according to the present embodiment.
- FIG. 4 is a diagram illustrating an example of a method for producing a positive electrode active material according to the present embodiment.
- FIG. 5 is a diagram illustrating an example of a method for producing a positive electrode active material according to the present embodiment.
- 6A and 6B are diagrams showing the evaluation results of S-TEM and EDX of the positive electrode active material of Example 1.
- FIG. FIG. 7 is a schematic view of a coin-type battery used for battery evaluation.
- FIG. 8 is a schematic view of a laminate type battery used for battery evaluation.
- 9 (A) and 9 (B) show the niobium content of the positive electrode active materials obtained in Examples 1-2, 5 and Comparative Examples 1-3, and the discharge capacity (A) or oxygen generation after 500 cycles. It is the graph which showed the relationship with quantity (B).
- 10A and 10B show the niobium content of the positive electrode active materials obtained in Examples 6 and 8 and Comparative Examples 6 to 8, the discharge capacity after 500 cycles (A) or the oxygen generation amount ( It is the graph which showed the relationship with B).
- 11A and 11B show the niobium content of the positive electrode active material obtained in Example 9 and Comparative Examples 9 to 11, the discharge capacity after 500 cycles (A) or the oxygen generation amount (B). It is the graph which showed the relationship.
- FIGS. 1A to 1C show a cathode active material for a nonaqueous electrolyte secondary battery according to the present embodiment (hereinafter “cathode active material 10”). It is also a diagram showing an example.
- the positive electrode active material 10 is composed of particles having a polycrystalline structure.
- the positive electrode active material 10 includes a lithium nickel manganese composite oxide 3 (hereinafter also referred to as “lithium metal composite oxide 3”) composed of secondary particles 2 in which a plurality of primary particles 1 are aggregated, and a lithium niobium compound 4. And including.
- the overall composition of the positive electrode active material 10 is represented by the general formula (1): Li d Ni 1 -a-b-c Mn a M b Nb c O 2 + ⁇ (general formula (1), M is Co, W , Mo, V, Mg, Ca, Al, Ti, Cr, Zr and Ta, 0.03 ⁇ a ⁇ 0.60, 0 ⁇ b ⁇ 0.60, 0. 02 ⁇ c ⁇ 0.08, a + b + c ⁇ 1, 0.95 ⁇ d ⁇ 1.20, and 0 ⁇ ⁇ ⁇ 0.5). That is, the positive electrode active material 10 contains niobium (Nb) in an amount of 2 atomic% to 8 atomic% with respect to the entire metal elements other than Li.
- Nb niobium
- niobium in the positive electrode active material 10 is partly dissolved in the primary particles 1 and partly exists as the lithium niobium compound 4 on the surface of the primary particles 1.
- the lithium niobium compound 4 is a compound containing at least lithium (Li) and niobium (Nb).
- a non-aqueous electrolyte secondary battery (hereinafter referred to as “secondary battery”) using the positive electrode active material 10 as described above has a high battery capacity and extremely high durability. Moreover, the secondary battery using the positive electrode active material 10 has higher thermal stability of the positive electrode active material during overcharge than the case where the positive electrode active material not containing niobium is used.
- the range of a indicating the Mn content is 0.03 ⁇ a ⁇ 0.60, preferably 0.05 ⁇ a ⁇ 0.60, more preferably 0.8. 10 ⁇ a ⁇ 0.55, more preferably 0.10 ⁇ a ⁇ 0.50, and still more preferably 0.12 ⁇ a ⁇ 0.45.
- the range of a is preferably 0.03 ⁇ a ⁇ 0.45, more preferably 0.03 ⁇ a ⁇ 0.45, and more preferably 0.03 ⁇ a ⁇ 0 from the viewpoint of higher battery capacity.
- the secondary battery can achieve both durability and thermal stability.
- the positive electrode active material can improve thermal stability by containing manganese, and can reduce the conductivity of the positive electrode active material by containing (solid solution) manganese and niobium in combination.
- the value of a is less than 0.03, the effect of improving the thermal stability cannot be obtained.
- the value of a exceeds 0.60, the battery capacity decreases.
- the range of c indicating the Nb content is 0.02 ⁇ c ⁇ 0.08, preferably 0.02 ⁇ c ⁇ 0.055.
- the range of c is the above range, extremely good durability can be obtained, and oxygen release can be suppressed when used for the positive electrode of the secondary battery, and high thermal stability can be obtained.
- the value of c is less than 0.02, niobium is dissolved in the primary particles, but the lithium niobium compound 4 is hardly formed, and the durability improving effect may not be sufficient.
- the value of c exceeds 0.08, a large amount of the lithium niobium compound 4 is generated, so that the battery capacity is greatly reduced.
- the range of c is more preferably 0.02 ⁇ c ⁇ 0.04. Moreover, when the range of c is 0.03 ⁇ c, there exists a tendency for it to be excellent by thermal stability.
- the composition of the positive electrode active material 10 can be measured by quantitative analysis using an inductively coupled plasma (ICP) emission analysis method. The presence of the lithium niobium compound 4 can be confirmed by, for example, X-ray diffraction (XRD).
- M indicating an additive element is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta.
- z exceeds 0, thermal stability, storage characteristics improvement, battery characteristics, etc. can be improved.
- M contains Co, the battery capacity and output characteristics are superior.
- M is Co, it is preferably 0.05 ⁇ z ⁇ 0.5, more preferably 0.05 ⁇ z ⁇ 0.4, and still more preferably 0.1 ⁇ z ⁇ 0.4.
- the range of z ′ is preferably 0.05 ⁇ z ′ ⁇ 0.5, more preferably 0.05 ⁇ z ′. ⁇ 0.4, more preferably 0.1 ⁇ z ′ ⁇ 0.4. Further, from the viewpoint of higher battery capacity, preferably 0.05 ⁇ z ′ ⁇ 0.45, more preferably 0.05 ⁇ z ′ ⁇ 0.35, and more preferably 0.05 ⁇ z ′ ⁇ 0.3. More preferably, 0.05 ⁇ z ′ ⁇ 0.2.
- the nickel content is represented by (1-abbc).
- the range of (1-abc) is preferably 0 ⁇ (1-abbc) ⁇ 0.95, more preferably 0.3 ⁇ (1-abbc) ⁇ . 0.95.
- the value of (1-abc) indicating the content of Ni indicates the content of Mn, Nb and M when the total of metal elements other than Li is 1. It depends on the values of a, b and c.
- d indicating the Li content may be 0.95 ⁇ d ⁇ 1.20, and 1 ⁇ d ⁇ 1.20.
- the positive electrode active material 10 a part of niobium is dissolved in the primary particles 1, and a part of niobium is present as the lithium niobium compound 4 on the surface of the primary particles 1.
- the reason why the battery characteristics and thermal stability are improved in the secondary battery using the positive electrode active material 10 is not particularly limited, but the effect of improving the thermal stability is mainly obtained by the solid solution of niobium in the primary particles 1. It can be considered that the durability improvement effect is mainly obtained by the lithium niobium compound 4 present on the surface of the primary particle 1.
- the solid solution of niobium in the primary particles 1 means that, for example, niobium is detected in the positive electrode active material 10 by ICP emission analysis, and EDX in a scanning transmission electron microscope (S-TEM) is used. This means a state in which niobium is detected in at least a portion of the primary particles 1 by surface analysis of the cross section of the primary particles 1 (see FIGS. 6A and 6B).
- niobium dissolved in the primary particles 1 is preferably detected over the entire surface of the primary particles 1.
- the niobium solid-dissolved in the primary particle 1 preferably has a maximum niobium concentration in the primary particle 1 of 1 to 3.5 times the average niobium concentration in the primary particle. It is preferably 3 times or less.
- the maximum niobium concentration in the primary particle 1 exceeds the above range, the variation of the niobium concentration in the primary particle 1 becomes large, and there are portions where the niobium concentration is locally high, while there are portions where the niobium concentration is locally low. It becomes like this.
- the maximum niobium concentration is preferably not more than twice the average niobium concentration in the primary particles 1.
- the maximum niobium concentration means an average value of the maximum niobium concentrations of 20 or more primary particles 1 arbitrarily selected as will be described later.
- the minimum niobium concentration in the primary particle 1 is the average niobium in the primary particle 1. It is preferably 50% or more with respect to the concentration.
- the minimum niobium concentration refers to an average value of minimum niobium concentrations of 20 or more primary particles 1 arbitrarily selected.
- the fluctuation of the niobium concentration in the primary particles 1 can be confirmed by linear analysis of the composition of the cross section of the primary particles 1 by EDX measurement with a scanning transmission electron microscope (S-TEM).
- S-TEM scanning transmission electron microscope
- the ratio of the maximum niobium concentration to the average niobium concentration in the primary particles 1 is selected, for example, by arbitrarily selecting 20 or more primary particles 1 from a plurality of secondary particles 2. It can be obtained by linearly analyzing the composition of the cross section of the primary particle by EDX of S-TEM.
- the direction of the line analysis is preferably the direction that is the maximum length of the cross section of the primary particle, but in the case where the influence of the niobium compound is excluded, the analysis is performed in a direction that allows analysis at a length of 50% or more of the maximum length. May be.
- the maximum niobium concentration and the average niobium concentration are obtained from the measured value of the niobium concentration of each primary particle 1 obtained by the line analysis, and the ratio of the maximum niobium concentration of each primary particle 1 (maximum niobium concentration / average niobium concentration) is obtained. Calculate each.
- the ratio of the maximum niobium concentration in the primary particles 1 can be determined by averaging the number of ratio values of the maximum niobium concentration calculated from the individual primary particles 1.
- concentration is a value in the primary particle 1
- the lithium niobium compound 4 of The fluctuation of the niobium concentration is measured by line analysis using EDX at a position where the measured value of the niobium concentration near the surface of the primary particle 1 is not affected by the presence.
- Nb niobium
- the positive electrode active material 10 has a lithium niobium compound 4 on the surface of the primary particles 1.
- the distribution of the lithium niobium compound 4 may be present on at least a part of the surface of the primary particle 1, and for example, may be present as particles on the surface of the primary particle 1 as shown in FIG.
- the entire surface of the primary particles may be coated.
- the particulate lithium niobium compound 4 and the lithium niobium compound 4 covering the entire primary particle may coexist.
- a part of the lithium niobium compound 4 may be present separately from the lithium metal composite oxide 3. If the lithium niobium compound 4 is present on at least a part of the primary particle surface, the durability of the obtained secondary battery can be enhanced.
- the presence of the lithium niobium compound 4 on the surface of the primary particles 1 indicates that the lithium metal composite oxide using EDX in a scanning transmission electron microscope (S-TEM) as shown in FIGS. 6 (A) and 6 (B).
- S-TEM scanning transmission electron microscope
- a portion having a high niobium concentration on the surface of the primary particle 1 (including the grain boundary) is detected (for example, the * portion in FIG. 6B), and This can be confirmed by identifying the composition of the niobium compound present in the positive electrode active material 10 by the X-ray diffraction method.
- the niobium concentration at the grain boundary or the surface of the primary particle 1 usually exceeds 3 times the niobium concentration (average) in the primary particle 1.
- Lithium niobium compound 4 has a high lithium ion conductivity and is considered to have an effect of accelerating the movement of lithium ions.
- Lithium niobium compound 4 formed on the surface of primary particles 1 is Li at the interface between the electrolyte and primary particles. The conduction path can be formed.
- the lithium niobium compound 4 has very high chemical stability. Therefore, it is possible to suppress the direct contact between the surface of the positive electrode active material 10 and the electrolyte solution, which is highly active during charging and discharging, while smoothly passing lithium ions, and to suppress the deterioration of the positive electrode active material 10, and as a result, extremely high It is thought that durability is obtained.
- the lithium niobium compound 4 preferably contains at least one selected from Li 3 NbO 4 , LiNbO 3 , Li 5 NbO 5, LiNb 3 O 8 and Li 8 Nb 2 O 9, and has a high durability improving effect. It is more preferable that 3 NbO 4 and LiNbO 3 are included, and it is more preferable that the material is composed of Li 3 NbO 4 . Moreover, the lithium niobium compound 4 may contain an amorphous phase at least partially. Since the amorphous phase is excellent in lithium ion conductivity, battery characteristics may be improved.
- the surface of the primary particle 1 on which the lithium niobium compound 4 is present is the surface of the primary particle 1 that can be contacted with the electrolytic solution.
- the surface of the primary particle 1 that can be contacted with the electrolytic solution includes not only the surface of the primary particle 1 exposed at the outer surface of the secondary particle, but also allows the electrolytic solution to penetrate through the outside of the secondary particle.
- gap inside a secondary particle, etc. are included. Further, the surface of the primary particle 1 that can be contacted with the electrolytic solution is included even if it is a grain boundary between the primary particles 1 as long as the bonding of the primary particles 1 is incomplete and the electrolytic solution can penetrate. .
- the lithium niobium compound 4 formed on the surface of the primary particle 1 that can be contacted with the electrolytic solution as described above can promote the movement of lithium ions in the positive electrode of the secondary battery. Therefore, by forming the lithium niobium compound 4 on the surface of the plurality of primary particles 1 that can be in contact with the electrolytic solution, the positive electrode active material 10 and the electrolytic solution are suppressed while suppressing an increase in the reaction resistance of the lithium metal composite oxide 3. It is possible to suppress the direct contact between the two, and it is possible to obtain higher durability.
- the lithium niobium compound 4 can be formed by increasing the niobium content within the range of the general formula (1) or by increasing the synthesis (firing) temperature. When the niobium content is increased within the range of the general formula (1), the crystallite diameter of the obtained lithium metal composite oxide 3 is reduced and the lithium niobium compound 4 is formed on the surface of the primary particles 1 as described later. High durability can be obtained.
- the lithium niobium compound 4 When the lithium niobium compound 4 is formed in a very small amount, it may be difficult to confirm the existence form. However, even in this case, as the element that forms a compound with niobium, surplus lithium existing on the surface of the primary particle 1 is conceivable. As described later, the niobium compound used in the manufacturing process reacts with surplus lithium. Thus, it is presumed that the lithium niobium compound 4 is formed. Further, the lithium niobium compound 4 may exist in a coexistence state of crystal and amorphous or in an amorphous state. On the other hand, when the lithium niobium compound 4 exists in a crystalline state, the presence can be confirmed by an X-ray diffraction method with an increase in the abundance.
- the lithium niobium compound 4 is assumed to promote the movement of lithium (Li) between the lithium nickel manganese composite oxide 3 and the electrolytic solution, and at least the surface of the primary particle 1
- the presence of the lithium niobium compound 4 in a part thereof suppresses the deterioration of the positive electrode active material 10 and provides high durability.
- the crystallite diameter of the lithium metal composite oxide 3 is not less than 50 nm and not more than 130 nm, preferably not less than 70 nm and not more than 130 nm.
- the crystallite diameter is in the above range, high durability can be obtained without reducing the battery capacity.
- the crystallite diameter is less than 50 nm, there are too many crystal grain boundaries and the resistance of the active material increases, so that sufficient charge / discharge capacity may not be obtained.
- the crystallite diameter exceeds 130 nm, crystal growth proceeds excessively, and cation mixing in which nickel is mixed into the lithium layer of the lithium metal composite oxide 3 that is a layered compound may occur, resulting in a decrease in charge / discharge capacity. .
- the crystallite diameter can be adjusted to the above range by adjusting crystallization conditions, Nb addition amount, firing temperature, firing time and the like.
- the crystallite diameter is obtained from the peak of the (003) plane in X-ray diffraction (XRD) using the Scherrer equation.
- the average particle diameter of the positive electrode active material 10 is preferably 5 ⁇ m or more and 20 ⁇ m or less, and more preferably 4 ⁇ m or more and 15 ⁇ m or less.
- the average particle diameter refers to the volume average particle diameter MV, and can be determined from, for example, a volume integrated value measured by a laser light diffraction / scattering particle size distribution meter.
- the secondary particles 2 constituting the lithium metal composite oxide 3 preferably have an average circularity, which is an index of sphericity, of 0.60 or more and 0.98 or less, and 0.70 or more and 0.98 or less. More preferably.
- the average degree of circularity is in the above range, the filling property of the secondary particles 2 becomes high, and a high energy density (volume energy density) can be imparted when used for the positive electrode of a battery. Further, since the specific surface area is increased, the contact efficiency with the electrolytic solution is increased, and the output characteristics can be improved. Note that the average circularity tends to be larger as the niobium content is increased (that is, the secondary particles 2 can be formed into a more spherical shape).
- the average circularity is calculated by, for example, arbitrarily selecting 30 or more secondary particles 2, obtaining the circularity E of each secondary particle 2 by the following formula (1), and using the average value. it can.
- the projected area S and the circumference L of each secondary particle 2 are image analysis for a particle having a particle size of 1 ⁇ m or more of the secondary particle 2 observed at a magnification of 1000 times by a scanning electron microscope (SEM). It can be obtained by software (for example, ImageJ).
- S 4 ⁇ S / L 2
- S is the projected area of the secondary particles
- L the peripheral length of the secondary particles
- ⁇ is the circumference ratio.
- FIGS. 2 to 5 show the production of the positive electrode active material for nonaqueous electrolyte secondary battery (hereinafter also referred to as “positive electrode active material”) according to the present embodiment. It is a figure which shows an example of a method.
- the lithium metal composite oxide 3 is composed of the secondary particles 2 in which a plurality of primary particles 1 as described above are aggregated, and at least a part of niobium is dissolved in the primary particles 1.
- a positive electrode active material including the lithium niobium compound 4 present on the surface of the primary particle 1 can be easily obtained on an industrial scale.
- Resulting positive electrode active material the general formula (1): Li d Ni 1 -a-b-c Mn a M b Nb c O 2 + ⁇
- M is Co, W, Mo, It is at least one element selected from V, Mg, Ca, Al, Ti, Cr, Zr and Ta, and 0.03 ⁇ a ⁇ 0.60, 0 ⁇ b ⁇ 0.60, 0.02 ⁇ c ⁇ 0.08, 0.95 ⁇ d ⁇ 1.20, and 0 ⁇ ⁇ ⁇ 0.5.
- the manufacturing method of the present embodiment is a niobium mixing step (step) of preparing a lithium niobium mixture containing nickel manganese composite hydroxide particles having a specific composition, a niobium compound, and a lithium compound. S10) and a firing step (step S20) of obtaining the lithium nickel manganese composite oxide by firing the lithium niobium mixture at 750 ° C. to 1000 ° C. in an oxidizing atmosphere.
- a method for producing the positive electrode active material of the present embodiment will be described with reference to FIGS. The following description is an example of a manufacturing method and does not limit the manufacturing method.
- a lithium niobium mixture containing nickel-manganese composite hydroxide particles (hereinafter also referred to as “composite hydroxide particles”), a niobium compound, and a lithium compound is prepared (step S10).
- the lithium niobium mixture may be obtained, for example, by adding the niobium compound to the composite hydroxide particles together with the lithium compound as a powder (solid phase) and mixing them (see FIG. 3). Further, the lithium niobium mixture is obtained, for example, by simultaneously adding a niobium salt solution and an acid to a slurry obtained by mixing composite hydroxide particles and water to obtain composite oxide particles coated with a niobium compound. Then, a lithium compound may be mixed (see FIG. 4). Details of the niobium mixing step (step S10) will be described below.
- the composite hydroxide particles contained in the lithium niobium mixture have the general formula (2): Ni 1-ab Mn a M b (OH) 2 + ⁇ (where M is Co, W, Mo , V, Mg, Ca, Al, Ti, Cr, Zr and Ta, 0.03 ⁇ a ⁇ 0.60, 0 ⁇ b ⁇ 0.60, 0 ⁇ ⁇ ⁇ 0.4).
- the content (composition) of the metal (Ni, Mn, M) in the composite hydroxide particles is substantially maintained even in the lithium metal composite oxide 3 finally obtained. Therefore, the content of each metal (Ni, Mn, M) is preferably in the same range as the content in the lithium metal composite oxide 3 described above.
- nickel composite hydroxide particles containing manganese in the above range are used.
- the lithium niobium mixture can be fired at a relatively high temperature.
- By firing at a high temperature manganese and niobium can be uniformly distributed (solid solution) in the plurality of primary particles of the obtained positive electrode active material.
- a positive electrode active material in which manganese and niobium are contained (solid solution) in a plurality of primary particles has high thermal stability and lowers electrical conductivity.
- the niobium mixing step includes, for example, a crystallization step (step S11) for obtaining composite oxide particles by crystallization, the obtained composite hydroxide particles, a lithium compound,
- a first mixing step of mixing a niobium compound to prepare a lithium niobium mixture step S12, hereinafter also referred to as “lithium niobium mixing step”.
- the manufacturing method of composite hydroxide particle is not specifically limited, As shown in FIG.3 and FIG.4, it is preferable to use the composite hydroxide particle obtained by the crystallization process (step S11).
- nickel and manganese are preferably uniformly contained in the particles, and the composite hydroxide in which each metal element is uniformly present in the primary particles by the crystallization step (step S11). Particles can be easily manufactured. For example, in the case of a mixture of nickel hydroxide particles and a manganese compound, or nickel hydroxide particles coated with a manganese compound, the distribution of manganese in the resulting positive electrode active material becomes uneven, The effect obtained by including manganese may not be sufficiently obtained.
- the crystallization step (step S11) can be performed by a known method as long as the composite hydroxide particles having the manganese content can be obtained.
- the composite hydroxide particles having the manganese content can be obtained.
- at least nickel and manganese are contained in the reaction vessel. While the mixed aqueous solution is stirred at a constant speed, a neutralizing agent is added and neutralized to control the pH, thereby generating composite hydroxide particles by coprecipitation.
- the mixed aqueous solution containing nickel and manganese for example, a sulfate solution, a nitrate solution, or a chloride solution of nickel and manganese can be used. Further, as will be described later, the mixed aqueous solution may contain the additive element M.
- the composition of the metal element contained in the mixed aqueous solution is almost the same as the composition of the metal element contained in the resulting composite hydroxide particles. Therefore, the composition of the metal element of the mixed aqueous solution can be prepared so as to be the same as the composition of the metal element of the target composite hydroxide particle.
- an alkaline aqueous solution can be used, and for example, sodium hydroxide, potassium hydroxide and the like can be used.
- reaction aqueous solution a complexing agent
- the complexing agent is not particularly limited as long as it can form a complex by binding to nickel ions or other metal ions in an aqueous solution in a reaction vessel (hereinafter also referred to as “reaction aqueous solution”), and is a known one.
- an ammonium ion supplier can be used.
- ammonia, ammonium sulfate, ammonium chloride, ammonium carbonate, ammonium fluoride etc. can be used.
- the temperature of the reaction aqueous solution is not using a complexing agent
- the temperature (liquid temperature) is preferably in the range of more than 60 ° C. and 80 ° C. or less.
- the solubility of Ni is increased, and the phenomenon that the precipitation amount of Ni deviates from the target composition and does not cause coprecipitation can be avoided.
- the temperature of the reaction aqueous solution exceeds 80 ° C.
- the amount of water evaporation increases, so the slurry concentration (reaction aqueous solution concentration) increases, Ni solubility decreases, and crystals such as sodium sulfate are generated in the filtrate.
- the charge / discharge capacity of the positive electrode active material is reduced, for example, the impurity concentration is increased.
- the pH of the aqueous reaction solution at the above temperature is preferably 10 or more and 12 or less (25 ° C. standard).
- the pH of the aqueous reaction solution exceeds 12, the resulting composite hydroxide particles become fine particles, the filterability also deteriorates, and spherical particles may not be obtained.
- the pH of the reaction aqueous solution is less than 10, the generation rate of composite hydroxide particles is remarkably slow, Ni remains in the filtrate, the amount of Ni precipitation deviates from the target composition, and the composite of the target ratio A hydroxide may not be obtained.
- the temperature of the reaction aqueous solution is 30 ° C. or higher and 60 ° C. or lower because the solubility of Ni in the reaction aqueous solution increases.
- the pH of the aqueous reaction solution is preferably 10 or more and 13 or less (at 25 ° C.).
- the ammonia concentration in the reaction aqueous solution is preferably maintained at a constant value within a range of 3 g / L to 25 g / L.
- the solubility of metal ions cannot be kept constant, so that primary particles of a composite hydroxide having a uniform shape and particle size may not be formed.
- gel-like nuclei are easily generated, the particle size distribution of the resulting composite hydroxide particles is also likely to be widened.
- the ammonia concentration exceeds 25 g / L, the solubility of metal ions becomes too high, the amount of metal ions remaining in the aqueous reaction solution increases, and the composition of the resulting composite hydroxide particles tends to shift. .
- the ammonia concentration is preferably maintained at a desired concentration by setting the upper and lower limits to about 5 g / L.
- a batch-type crystallization method may be used, or a continuous crystallization method may be used.
- a composite hydroxide particle can be obtained by collecting a precipitate after the reaction aqueous solution in the reaction tank reaches a steady state, filtering and washing with water.
- a mixed aqueous solution and an alkaline aqueous solution, and in some cases, an aqueous solution containing an ammonium ion supplier are continuously supplied to overflow from the reaction vessel, and a precipitate is collected, filtered, washed with water and combined. Hydroxide particles can be obtained.
- the composite hydroxide particles are at least one selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr and Ta as shown in the general formula (2).
- An element hereinafter also referred to as “additive element M” may be included.
- a method for blending the additive element M in the composite hydroxide particles is not particularly limited, and a known method can be used. For example, from the viewpoint of increasing productivity, a method of adding an aqueous solution containing the additive element M to a mixed aqueous solution containing nickel and manganese and coprecipitating composite hydroxide particles containing the additive element M is preferable.
- aqueous solution containing the additive element M examples include cobalt sulfate, sodium tungstate, tungsten oxide, molybdenum oxide, molybdenum sulfide, vanadium pentoxide, magnesium sulfate, magnesium chloride, calcium chloride, aluminum sulfate, sodium aluminate, titanium sulfate, An aqueous solution containing ammonium peroxotitanate, potassium potassium oxalate, zirconium hydroxide, zirconium sulfate, chromium chloride, sodium tantalate, tantalate, or the like can be used.
- the method for coating the additive element M is not particularly limited, and a known method can be used.
- the coating method of the additive element M will be described below.
- the composite hydroxide particles obtained by crystallization are dispersed in pure water to obtain a slurry.
- a solution containing M corresponding to the target coating amount is mixed with this slurry, and acid is added dropwise to adjust to a predetermined pH.
- the acid for example, sulfuric acid, hydrochloric acid, nitric acid and the like are used.
- the slurry is filtered and dried, and composite hydroxide particles coated with the additive element M can be obtained.
- a spray dry method in which a solution containing a compound containing M is sprayed on the composite hydroxide particles and then dried, or a solution containing a compound containing M is impregnated in the composite hydroxide particles. The method etc. are mentioned.
- grains mixes additive element M in said mixed aqueous solution, and coat
- the additive element M may be coated on a nickel-containing hydroxide crystallized by adding an alkaline aqueous solution to a mixed aqueous solution containing nickel and manganese (excluding the additive element M).
- the content of M may be adjusted by coating.
- the lithium niobium mixing step (step S12) is a step of obtaining the lithium niobium mixture by mixing the composite hydroxide particles obtained above, the niobium compound, and the lithium compound.
- niobium compound a known compound containing niobium can be used.
- niobic acid, niobium oxide, niobium nitrate, niobium pentachloride, niobium nitrate and the like can be used.
- the niobium compound is preferably niobic acid, niobium oxide, or a mixture thereof from the viewpoint of easy availability and avoiding contamination of impurities in the lithium metal composite oxide 3.
- an impurity mixes in the lithium metal complex oxide 3 the thermal stability, battery capacity, and cycle characteristics of the obtained secondary battery may be reduced.
- the niobium compound is preferably mixed in particles (solid phase).
- the reactivity in the subsequent firing step (step S20) varies depending on the particle size of the niobium compound, and thus the particle size of the niobium compound to be used is an important factor.
- the average particle size of the niobium compound is preferably 0.01 ⁇ m or more and 10 ⁇ m or less, more preferably 0.05 ⁇ m or more and 3.0 ⁇ m or less, and further preferably 0.08 ⁇ m or more and 1.0 ⁇ m or less.
- the average particle size is smaller than 0.01 ⁇ m, the niobium compound is scattered in the problem that the handling of the powder becomes very difficult and in the lithium niobium mixing step (step S12) and the firing step (step S20). There may be a problem that the composition cannot be added to the active material.
- the average particle size is larger than 10 ⁇ m, Nb is not uniformly distributed in the fired lithium metal composite oxide, and thermal stability may not be ensured.
- the average particle diameter is the volume average particle diameter MV, and can be obtained from, for example, a volume integrated value measured by a laser light diffraction / scattering particle size distribution meter.
- the niobium compound may be pulverized in advance using various pulverizers such as a ball mill, a planetary ball mill, a jet mill / nano jet mill, a bead mill, and a pin mill so as to have a particle size in the above range. Further, the niobium compound may be classified by a dry classifier or sieving as necessary. For example, sieving can be performed to obtain particles having an average particle size close to 0.01 ⁇ m.
- the lithium compound is not particularly limited, and a known compound containing lithium can be used.
- a known compound containing lithium can be used.
- lithium carbonate, lithium hydroxide, lithium nitrate, or a mixture thereof can be used.
- lithium carbonate, lithium hydroxide, or a mixture thereof is preferable from the viewpoint of being less affected by residual impurities and being dissolved at a firing temperature.
- the mixing method of the composite hydroxide particles, the lithium compound, and the niobium compound is not particularly limited, and the composite hydroxide particles, the lithium compound, and the niobium compound are sufficient as long as the composite hydroxide particles and the like are not destroyed.
- To be mixed it can mix using a general mixer, for example, can be mixed using a shaker mixer, a Laedige mixer, a Julia mixer, a V blender etc., for example.
- the lithium niobium mixture is preferably mixed well before the firing step (step S20) described later. If the mixing is not sufficient, the ratio of Li to the metal element Me other than Li (Li / Me) may vary among the individual particles of the positive electrode active material, resulting in problems such as insufficient battery characteristics. .
- the lithium compound is mixed so that Li / Me in the lithium niobium mixture is 0.95 or more and 1.20 or less. That is, it mixes so that Li / Me in a lithium niobium mixture may become the same as Li / Me in the positive electrode active material obtained. This is because the molar ratio of Li / Me and each metal element does not change before and after the firing step (step S20), so that Li / Me of the lithium niobium mixture in this mixing step (step S12) is Li This is because / Me.
- the niobium compound has a niobium content in the lithium niobium mixture of 0.03 atomic% or more with respect to the total of metal elements other than Li (Ni, Mn, additive elements M, Nb) in the lithium niobium mixture. It mixes so that it may become atomic% or less.
- the niobium mixing step includes, for example, a crystallization step (step S11) for obtaining composite oxide particles by crystallization, the obtained composite hydroxide particles, water, A niobium coating solution (step S13) to obtain a composite hydroxide particle coated with a niobium compound by adding a niobium salt solution and an acid to the slurry obtained by mixing, and a composite coated with the niobium compound A second mixing step of mixing the hydroxide particles and the lithium compound to obtain a lithium niobium mixture (step S14, hereinafter also referred to as “lithium mixing step”) may be included.
- each step will be described.
- the crystallization process is the same process as the above, the description is abbreviate
- the niobium coating step (step S13) is a step of coating the composite hydroxide particles obtained in the crystallization step (step S11) with a niobium compound.
- the niobium compound coating is performed, for example, by adding a niobium salt solution and an acid to a slurry obtained by mixing composite hydroxide particles and water, and then adding a niobium compound (for example, on the surface of the composite hydroxide particles). , Niobium hydroxide, etc.).
- the method for producing such niobium-coated composite hydroxide particles is described in, for example, International Publication No. 2014/034430. For detailed conditions, refer to these documents and the like as appropriate. Can be adjusted.
- the niobium salt solution is not particularly limited as long as it contains a niobium salt having a sufficiently high solubility in water.
- a aqueous solution in which at least one of niobium hydroxide, niobium metal, and niobium pentachloride is dissolved in an aqueous caustic potash solution.
- ferroniobium may be dissolved in a caustic potash solution.
- the niobium salt solution is preferably prepared by dissolving the niobium salt in a caustic potash aqueous solution having a caustic potash concentration of 150 g / L or more and 500 g / L or less and a temperature exceeding 60 ° C. and not exceeding 90 ° C.
- concentration of caustic potash is less than 150 g / L, niobium cannot be sufficiently dissolved, and niobium remains in the residue.
- concentration of caustic potash exceeds 500 g / L, it is close to the saturated concentration of caustic potash and niobium cannot be dissolved.
- the niobium salt concentration in the niobium salt solution is preferably 5 g / L or more and 40 g / L. When the niobium salt concentration is in the above range, the productivity of the composite hydroxide particles coated with the niobium compound can be increased.
- Ferroniob is not particularly limited as long as it is a generally available product, regardless of the shape of powder, granule, or lump.
- the reaction conditions for dissolving ferroniobium vary slightly depending on the desired niobium concentration, but the caustic potash concentration should be 150 to 500 g / L and should be in the range from 60 ° C to 90 ° C. preferable.
- iron can be left in the residue, and the residue is filtered to obtain a niobium salt solution in which only niobium is dissolved.
- niobium salt for preparing a niobium salt solution As a niobium salt for preparing a niobium salt solution, ortho niobate (M 3 NbO 4 : M is a monovalent element other than Nb and O) or meta niobate (MNbO 3 : M is Nb
- M 3 NbO 4 M is a monovalent element other than Nb and O
- MNbO 3 M is Nb
- oxidation proceeds during hydrolysis or dissolution, and niobium hydroxide or insoluble niobium oxide is generated. May not dissolve.
- a method of adding the niobium salt solution and the acid to the slurry obtained by mixing the composite hydroxide particles and water is not particularly limited, and a known method can be used. While stirring the slurry, the niobium salt solution and the acid can be added simultaneously to achieve a predetermined pH.
- the pH (at 25 ° C.) at this time is preferably 7 or more and 11 or less, and more preferably 7 or more and less than 9.
- pH is the said range, melt
- niobium salt solution and the acid are added at the same time, niobium hydroxide and the like are not easily precipitated and aggregated as a single substance, and an effect is obtained that the surface of the composite hydroxide can be uniformly coated.
- the acid is not particularly limited, and a known acid can be used, but sulfuric acid, hydrochloric acid, and the like are preferable from the viewpoint of being inexpensive and easy to use industrially. Moreover, as acid concentration to add, 10 mass% or more and 50 mass% or less are preferable with respect to the acid aqueous solution whole quantity.
- the lithium mixing step (step S14) is a step in which the composite hydroxide particles coated with the above-mentioned niobium compound and the lithium compound are mixed to obtain a lithium niobium mixture.
- the same lithium niobium mixing step (step S12) can be used.
- the mixing of the composite hydroxide particles coated with the niobium compound and the lithium compound can be performed under the same conditions as in the lithium niobium mixing step (step S12).
- the manufacturing method of this embodiment is a process (step S16) of heat-treating the composite hydroxide particles or the niobium-coated composite hydroxide particles before the above-described mixing step (steps S12 and S14). ) May be included.
- the heat treatment step (step S16) is a step of removing at least a part of moisture contained in the composite hydroxide particles by heat treatment. By removing at least a part of the water remaining in the composite hydroxide particles, it is possible to prevent variation in Li / Me of the positive electrode active material obtained in the firing step (step S20).
- the composite hydroxide particles are sufficiently oxidized and converted to the composite oxide particles from the viewpoint of further reducing the variation in Li / Me.
- the heat treatment step (step S16) is performed, as shown in FIG. 5, the niobium mixing step (step S10) is performed by heat-treating the composite hydroxide particles before adjusting the lithium niobium mixture, and then the heat treatment.
- the later composite hydroxide particles and / or composite oxide particles, a lithium compound, and a niobium compound can be mixed to prepare a lithium niobium mixture.
- the composite hydroxide particles may be coated with a compound containing the additive element M, and then heat treatment may be performed.
- the composite hydroxide particles after the heat treatment and / or The compound oxide particles may be coated with a compound containing the additive element M.
- the resulting niobium-coated composite hydroxide particles may be heat-treated, and the niobium-coated composite hydroxide particles after the heat treatment and / or Alternatively, niobium-coated composite oxide particles and a lithium compound may be mixed to obtain a lithium niobium mixture (step S14).
- the heat treatment may be performed up to a temperature at which residual moisture in the composite hydroxide particles is removed.
- the temperature of the heat treatment is preferably 105 ° C. or higher and 700 ° C. or lower.
- the composite hydroxide particles are heated at 105 ° C. or higher, at least a part of residual moisture can be removed.
- the temperature of the heat treatment is less than 105 ° C., it takes a long time to remove residual moisture, which is not industrially suitable.
- the temperature of the heat treatment exceeds 800 ° C., the particles converted into composite oxide particles may sinter and aggregate.
- the heat treatment temperature is preferably 350 ° C. or higher and 700 ° C. or lower.
- the atmosphere in which the heat treatment is performed is not particularly limited. For example, it is preferably performed in an air stream from the viewpoint of easy operation.
- the time of heat processing is not specifically limited, For example, it can be made into 1 hour or more. When the heat treatment time is less than 1 hour, residual moisture in the composite hydroxide particles may not be sufficiently removed.
- the heat treatment time is preferably 5 hours or more and 15 hours or less.
- the equipment used for the heat treatment is not particularly limited as long as the composite hydroxide particles can be heated in an air stream, and for example, a blow dryer, an electric furnace without gas generation, or the like can be suitably used. .
- the composite hydroxide particles obtained in the crystallization step (step S11) are heat-treated (roasted) at 150 to 700 ° C. for 1 to 10 hours,
- the obtained composite oxide particles, niobium compound, and lithium compound may be mixed to form a lithium niobium mixture.
- the composite oxidation represented by the general formula (3) is used instead of the composite hydroxide particles used in the lithium niobium mixing step (step S12).
- the lithium niobium mixing step (step S12) is selected from the nickel manganese composite hydroxide particles represented by the general formula (2) and the nickel manganese composite oxide particles represented by the general formula (3).
- a lithium niobium mixture containing one or more of the above, a niobium compound, and a lithium compound may be prepared.
- the nickel manganese composite oxide particles represented by the general formula (3) may be obtained by a method other than heat treatment.
- the firing step (step S20) is a step of firing the lithium niobium mixture at 750 ° C. to 1000 ° C. in an oxidizing atmosphere.
- the lithium niobium mixture is baked, lithium in the lithium compound diffuses into the composite hydroxide particles (see FIG. 3) or the niobium-coated composite hydroxide particles (see FIG. 4) described later.
- Lithium metal composite oxide 3 is formed.
- the lithium compound melts at the firing temperature and penetrates into the composite hydroxide particles to form the lithium metal composite oxide 3.
- the niobium compound first penetrates into the secondary particles together with the molten lithium compound, and penetrates between the primary particles if there is a grain boundary or the like.
- the niobium compound permeates into the grain boundaries between the secondary particles and between the primary particles, so that the diffusion of niobium inside the primary particles is promoted, and niobium is uniformly dissolved in the primary particles.
- the amount of niobium to be added exceeds the limit of solid solution in the primary particles, so that it reacts with the excess lithium content, and the lithium niobium compound is a primary particle surface, grain boundary, or a simple substance. It is formed.
- Calcination temperature is 750 ° C. or higher and 1000 ° C. or lower, preferably 750 ° C. or higher and 950 ° C. or lower in an oxidizing atmosphere. Further, the lower limit of the firing temperature may be 800 ° C. or higher, or may be 850 ° C. or higher.
- the lithium niobium mixture can increase the firing temperature by containing manganese. By increasing the firing temperature, the diffusion of niobium is promoted and the formation of the lithium niobium compound is promoted. Furthermore, the crystallinity of the lithium nickel manganese composite oxide is increased, and the battery capacity can be further improved.
- the firing temperature is less than 750 ° C.
- the diffusion of lithium and niobium into the nickel manganese composite hydroxide particles is not sufficiently performed, and surplus lithium and unreacted particles remain or the crystal structure is sufficient.
- sufficient battery characteristics cannot be obtained.
- a calcination temperature exceeds 1000 degreeC, while forming intense sintering between the formed lithium metal complex oxide particles, there exists a possibility of producing abnormal grain growth. If abnormal grain growth occurs, the particles after firing become coarse and may not retain the particle form, and when the positive electrode active material is formed, the specific surface area decreases and the positive electrode resistance increases. There arises a problem that the battery capacity decreases.
- the firing time is preferably at least 3 hours or more, more preferably 6 hours or more and 24 hours or less. When the firing time is less than 3 hours, the lithium metal composite oxide may not be sufficiently generated.
- the firing atmosphere is an oxidizing atmosphere, and an atmosphere having an oxygen concentration of 3 to 100% by volume is more preferable. That is, firing is preferably performed in the air or in an oxygen stream. This is because, if the oxygen concentration is less than 3% by volume, it cannot be oxidized sufficiently and the crystallinity of the lithium metal composite oxide may be insufficient. Considering battery characteristics in particular, it is preferable to carry out in an oxygen stream.
- the furnace used for firing is not particularly limited as long as it can fire the lithium niobium mixture in the air or an oxygen stream, but it is preferable to use an electric furnace that does not generate gas.
- the firing furnace either a batch type furnace or a continuous type furnace can be used.
- the firing step (step S20) may further include a step of calcining at a temperature lower than the firing temperature before firing at a temperature of 750 ° C. or higher and 1000 ° C. or lower.
- the calcination is preferably performed at a temperature at which the lithium compound and / or niobium compound in the lithium niobium mixture can melt and react with the composite hydroxide particles.
- the calcination temperature can be set to 350 ° C. or higher and lower than the firing temperature, for example.
- the lower limit of the calcining temperature is preferably 400 ° C. or higher.
- the lithium compound and / or niobium compound penetrates into the composite hydroxide particles, and the lithium and niobium are sufficiently diffused to form a uniform composition.
- the lithium metal composite oxide 3 can be easily obtained.
- the calcination is preferably performed at a temperature of 400 ° C. or higher and 550 ° C. or lower for 1 hour to 10 hours.
- the particle size distribution can be adjusted by eliminating the above-mentioned sintering and aggregation by crushing.
- Non-aqueous electrolyte secondary battery (hereinafter also referred to as “secondary battery”) of the present embodiment uses the above-described positive electrode active material for the positive electrode.
- the secondary battery of the present embodiment includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, and includes the same components as a general lithium ion secondary battery.
- the embodiment described below is merely an example, and the nonaqueous electrolyte secondary battery may be implemented in various modifications and improvements based on the knowledge of those skilled in the art, including the following embodiment. it can. Further, the use of the secondary battery is not particularly limited.
- a positive electrode of a secondary battery is manufactured using the positive electrode active material.
- the positive electrode active material binder
- the conductive material conductive material
- the binder binder
- activated carbon or a solvent for viscosity adjustment is added, and this is kneaded to obtain a positive electrode.
- a composite paste is prepared.
- the mixing ratio of each material in the positive electrode mixture is an element that determines the performance of the lithium secondary battery, it can be adjusted according to the application.
- the mixing ratio of the materials can be the same as that of the positive electrode of a known lithium secondary battery.
- the positive electrode active material is 60%. Up to 95% by mass, 1 to 20% by mass of a conductive material, and 1 to 20% by mass of a binder can be contained.
- the obtained positive electrode mixture paste is applied to, for example, the surface of a current collector made of aluminum foil, and dried to disperse the solvent, thereby producing a sheet-like positive electrode. If necessary, pressurization may be performed by a roll press or the like to increase the electrode density.
- the sheet-like positive electrode thus obtained can be cut into an appropriate size according to the target battery and used for battery production.
- the manufacturing method of the positive electrode is not limited to the above-described examples, and may depend on other methods.
- the conductive material for example, graphite (natural graphite, artificial graphite, expanded graphite and the like), carbon black materials such as acetylene black and ketjen black, and the like can be used.
- binder As the binder (binder), it plays the role of holding the active material particles.
- PVDF polyvinylidene fluoride
- PTFE polytetrafluoroethylene
- fluoro rubber ethylene propylene diene rubber
- styrene butadiene cellulose series Resins
- polyacrylic acid can be used.
- a positive electrode active material, a conductive material, and activated carbon are dispersed, and a solvent that dissolves the binder is added to the positive electrode mixture.
- a solvent that dissolves the binder is added to the positive electrode mixture.
- an organic solvent such as N-methyl-2-pyrrolidone can be used as the solvent.
- Activated carbon can be added to the positive electrode mixture in order to increase the electric double layer capacity.
- the negative electrode metallic lithium, a lithium alloy, or the like can be used.
- the negative electrode is prepared by mixing a negative electrode active material capable of occluding and desorbing lithium ions with a binder and adding a suitable solvent to form a paste on the surface of a metal foil current collector such as copper. You may use what was formed by compressing in order to apply
- the negative electrode active material for example, a fired organic compound such as natural graphite, artificial graphite, and phenol resin, and a powdery carbon material such as coke can be used.
- a fluorine-containing resin such as PVDF can be used as the negative electrode binder as in the positive electrode
- an organic material such as N-methyl-2-pyrrolidone can be used as a solvent for dispersing these active materials and the binder.
- a solvent can be used.
- a separator is interposed between the positive electrode and the negative electrode.
- the separator separates the positive electrode and the negative electrode and holds the electrolyte, and a known one can be used.
- a thin film such as polyethylene or polypropylene and a film having a large number of minute holes can be used. it can.
- Non-aqueous electrolyte The nonaqueous electrolytic solution is obtained by dissolving a lithium salt as a supporting salt in an organic solvent.
- organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate and trifluoropropylene carbonate, chain carbonates such as diethyl carbonate, dimethyl carbonate, ethylmethyl carbonate and dipropyl carbonate, tetrahydrofuran, 2- Use one kind selected from ether compounds such as methyltetrahydrofuran and dimethoxyethane, sulfur compounds such as ethyl methyl sulfone and butane sultone, phosphorus compounds such as triethyl phosphate and trioctyl phosphate, or a mixture of two or more. Can do.
- the non-aqueous electrolyte solution may contain a radical scavenger, a surfactant, a flame retardant, and the like.
- the non-aqueous electrolyte secondary battery of the present embodiment constituted by the positive electrode, the negative electrode, the separator, and the non-aqueous electrolyte described above can be formed in various shapes such as a cylindrical shape and a laminated shape.
- the positive electrode and the negative electrode are laminated via a separator to form an electrode body, and the obtained electrode body is impregnated with a non-aqueous electrolyte and communicated with the positive electrode current collector and the outside. Connect between the positive electrode terminal and between the negative electrode current collector and the negative electrode terminal leading to the outside using a current collecting lead, etc., and seal the battery case to complete the nonaqueous electrolyte secondary battery. .
- the secondary battery according to the present embodiment can achieve both high battery capacity and durability and high thermal stability by suppressing oxygen release during overcharge. Moreover, the positive electrode active material used for the secondary battery which concerns on this embodiment can be obtained with the above industrial manufacturing methods. Therefore, the secondary battery according to this embodiment is used as a power source for small portable electronic devices (such as notebook personal computers and mobile phone terminals) that always require high capacity, a power source for electric vehicles, a power source for hybrid vehicles, and the like. It can be used suitably.
- the analysis method of the metal contained in the positive electrode active material in an Example and a comparative example and the various evaluation methods of a positive electrode active material are as follows.
- Composition analysis The composition of the obtained nickel manganese composite hydroxide and the positive electrode active material was measured by ICP emission analysis.
- Average particle size MV The average particle size (volume average particle size MV) was measured with a laser diffraction / scattering particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac HRA).
- the composition of the primary particle cross section was subjected to line analysis by EDX of S-TEM.
- the direction of the line analysis is the direction in which the measured value of the niobium concentration near the surface of the primary particle is not influenced by the surface analysis in advance and the presence of the niobium compound on the surface of the primary particle, and the maximum length of the primary particle.
- the direction that can be analyzed with a length of 50% or more of was selected.
- the ratio of the maximum niobium concentration of the positive electrode active material was determined by averaging the ratio of the maximum niobium concentration.
- Initial charge capacity and initial discharge capacity The initial charge capacity and initial discharge capacity were left for about 24 hours after the coin-type battery CBA shown in FIG. 7 was produced, and the open circuit voltage OCV (open circuit voltage) was stabilized. Thereafter, the current density with respect to the positive electrode is set to 0.1 mA / cm 2 and charged to a cutoff voltage of 4.3 V to obtain an initial charge capacity. After one hour of rest, the capacity when discharged to a cutoff voltage of 3.0 V is initially discharged. The capacity. For the measurement of the discharge capacity, a multi-channel voltage / current generator (manufactured by Advantest Corporation, R6741A) was used.
- the coin-type battery CBA was produced by the following method. First, 52.5 mg of the obtained positive electrode active material, 15 mg of acetylene black, and 7.5 mg of polytetrafluoroethylene resin (PTFE) were mixed and press-molded to a diameter of 11 mm and a thickness of 100 ⁇ m at a pressure of 100 MPa, as shown in FIG. A positive electrode (evaluation electrode) PE was prepared. The produced positive electrode PE was dried at 120 ° C. for 12 hours in a vacuum dryer, and then a 2032 type coin battery CBA was produced using this positive electrode PE in an Ar atmosphere glove box in which the dew point was controlled at ⁇ 80 ° C.
- PTFE polytetrafluoroethylene resin
- Lithium (Li) metal having a diameter of 17 mm and a thickness of 1 mm is used for the negative electrode NE, and the electrolyte solution is an equal volume mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) using 1M LiClO 4 as a supporting electrolyte ( Toyama Pharmaceutical Co., Ltd.) was used.
- EC ethylene carbonate
- DEC diethyl carbonate
- 1M LiClO 4 1M LiClO 4 as a supporting electrolyte
- separator SE a polyethylene porous film having a film thickness of 25 ⁇ m was used.
- the coin battery had a gasket GA and a wave washer WW, and was assembled into a coin-type battery with the positive electrode can PC and the negative electrode can NC.
- the laminate type battery LBA was produced by the following method. First, the obtained positive electrode active material was mixed with acetylene black (conductive material) and PVDF (binder) in a mass ratio of 85: 10: 5 and dispersed in NMP (N-methyl-2-pyrrolidinone) as a solvent. To make a slurry. This positive electrode slurry was applied to an aluminum foil (positive electrode current collector) having a thickness of 20 ⁇ m at a rate of 7 mg / cm 2 per unit area using an applicator. Then, it dried at 120 degreeC * 30 minutes with the ventilation dryer, and rolled with the roll press, and 5.0 cm x 3.0 cm positive electrode PS was obtained.
- NMP N-methyl-2-pyrrolidinone
- a negative electrode material for lithium ion secondary batteries (natural graphite) manufactured by Mitsubishi Chemical and acetylene black were mixed at a mass ratio of 97: 3, and dispersed in NMP as a solvent to form a slurry.
- This negative electrode slurry was applied to a 15 ⁇ m thick Cu current collector (negative electrode current collector) at a thickness of 5.0 mg / cm 2 using an applicator. Then, after drying at 120 ° C. for 30 minutes with a blower dryer, the dried electrode was rolled using a roll press.
- the negative electrode sheet after rolling is cut into a rectangle with a strip-shaped portion (terminal) having a width of 5.4 cm ⁇ 3.4 cm and a corner of 10 mm, the active material layer is removed from the strip-shaped portion, and the copper foil is exposed to form a terminal Part was formed and the negative electrode sheet NS with a terminal was obtained.
- the separator SE2 a commonly used polyethylene separator having a thickness of 16 ⁇ m was used.
- the positive electrode PS and the negative electrode NS are used as electrode portions laminated via the separator SE2, and the obtained electrode portions are impregnated with an electrolytic solution, and sealed in a battery casing to obtain a laminate cell type A battery LBA was assembled.
- the obtained laminated battery LBA was CC charged to 4.1 V at a rate of 2C at a temperature of 60 ° C., paused for 10 minutes, then CC discharged to 3.0 V at the same rate and paused for 10 minutes.
- the charge / discharge cycle (2C rate, 3.0-4.1 V) was repeated 500 cycles.
- the discharge capacities at the first cycle and the 500th cycle were measured, and the percentage of the 2C discharge capacity at the 500th cycle with respect to the 2C discharge capacity at the 1st cycle was determined as the capacity retention rate (%).
- thermal stability of the positive electrode was evaluated by determining the amount of oxygen released by heating the positive electrode active material in an overcharged state.
- a coin-type battery CBA similar to (5) was prepared, and CCCV charged (constant current-constant voltage charging) at a 0.2 C rate up to a cutoff voltage of 4.5V. Thereafter, the coin battery was disassembled, and only the positive electrode was carefully taken out so as not to be short-circuited, washed with DMC (dimethyl carbonate), and dried. About 2 mg of the dried positive electrode was weighed and heated from room temperature to 450 ° C.
- GCMS gas chromatograph mass spectrometer
- Helium was used as the carrier gas.
- the semi-quantitative value of the oxygen generation amount was calculated by injecting pure oxygen gas into the GCMS as a standard sample and extrapolating a calibration curve obtained from the measurement result.
- Example 1 (Crystallization process) A predetermined amount of pure water was put into a reaction tank (60 L), and the temperature in the tank was set to 45 ° C. while stirring. At this time, N 2 gas was allowed to flow into the reaction tank, and the dissolved oxygen concentration in the reaction tank liquid was adjusted to 0.8 mg / L. A 2.0M mixed aqueous solution of nickel sulfate, cobalt sulfate, and manganese sulfate, and 25% by mass sodium hydroxide as an alkaline solution so that the molar ratio of nickel: cobalt: manganese in this reaction tank is 60:20:20. The solution and 25% by mass aqueous ammonia as a complexing agent were simultaneously and continuously added to the reaction vessel.
- the flow rate was controlled so that the residence time of the mixed aqueous solution was 8 hours, the pH in the reaction vessel was adjusted to 11.8 to 12.1, and the ammonia concentration was adjusted to 12 to 13 g / L.
- a slurry containing nickel cobalt manganese composite hydroxide was recovered from the overflow port, followed by filtration to obtain a nickel cobalt manganese composite hydroxide cake (crystallization step). Thereafter, impurities were washed by passing 1 L of pure water through 140 g of nickel cobalt manganese composite hydroxide in the filtered Denver.
- the powder after washing was dried to obtain nickel cobalt manganese composite hydroxide particles represented by Ni 0.60 Co 0.20 Mn 0.20 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4).
- the average particle diameter MV of the obtained composite hydroxide was 9.9 ⁇ m.
- Nithium niobium mixing process The obtained nickel-cobalt-manganese composite hydroxide particles, lithium carbonate, and niobic acid (Nb 2 O 5 ⁇ nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed in a molar ratio of nickel: cobalt: manganese: niobium. Is 59.1: 19.2: 19.2: 2.5, and the atomic ratio of the lithium amount (Li) to the total metal amount (Me) of nickel, cobalt, manganese, and niobium (hereinafter, Weighed so that Li / Me) was 1.03. Thereafter, the mixture was sufficiently mixed using a shaker mixer device (TURBULA Type T2C manufactured by Willy et Bacofen (WAB)) to obtain a lithium mixture.
- TURBULA Type T2C manufactured by Willy et Bacofen (WAB)
- the obtained lithium mixture was calcined by holding at 900 ° C. for 10 hours in an air stream (oxygen: 21 vol%), and then pulverized to obtain a positive electrode active material comprising lithium nickel cobalt manganese niobium composite oxide. It was.
- Table 1 shows the volume average particle diameter MV of the obtained positive electrode active material.
- a peak attributed to Li 3 NbO 4 (ICDD card No. 75-902) was confirmed.
- the increase of the lattice constants a and c of lithium nickel cobalt manganese composite oxide was recognized.
- niobium was dissolved in the crystal structure (FIGS. 6A and 6B).
- segregation that appears to be a lithium niobium compound was confirmed on the grain boundaries and the active material surface from the results of EDX ray analysis (* portion in FIG. 6B).
- this compound When combined with the results of XRD measurement, this compound is presumed to be Li 3 NbO 4 . Further, from the XRD measurement result, the crystallite diameter of the (003) plane was calculated using the Scherrer equation, and was 1005 mm (100.5 nm).
- Example 2 The obtained nickel-cobalt-manganese composite hydroxide particles, lithium carbonate, and niobic acid (Nb 2 O 5 .nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed at a molar ratio of nickel: cobalt: manganese: niobium.
- a positive electrode active material was obtained and evaluated in the same manner as in Example 1 except that it was weighed so that 58.8: 19.0: 19.0: 3.2. The evaluation results are shown in Tables 1 and 2.
- Example 3 (Crystallization process) In the same manner as in the crystallization step of Example 1, nickel cobalt manganese composite hydroxide particles represented by Ni 0.60 Co 0.20 Mn 0.20 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4) were used. Obtained. (Niobium coating process) Next, niobic acid (Nb 2 O 5 ⁇ nH 2 O) powder was kept constant at 80 ° C. in a caustic potash solution having a concentration of 300 g / L so that the niobium concentration was 30 g / L, and stirred for 2 hours. After dissolution, the residue was filtered to prepare a niobium salt solution.
- Ni 0.60 Co 0.20 Mn 0.20 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4) were used. Obtained.
- Niobium coating process Next, niobic acid (Nb 2 O 5 ⁇ nH 2 O) powder was kept constant at 80 ° C. in a caus
- a niobium salt solution and a 25% by mass sulfuric acid aqueous solution are simultaneously added dropwise to a slurry obtained by mixing the nickel cobalt manganese composite hydroxide with pure water so that the pH is 8.0 while maintaining the solution temperature at 25 ° C.
- a nickel-cobalt composite hydroxide coated with was obtained.
- the target addition amount of niobium was 2.5 (molar ratio).
- Li / Me The atomic ratio (hereinafter referred to as Li / Me) of the obtained niobium-coated nickel cobalt manganese composite hydroxide particles and the total metal amount of lithium carbonate and lithium, nickel, cobalt, manganese and niobium is 1.03.
- Example 4 In the same manner as in the crystallization step of Example 1, nickel cobalt manganese composite hydroxide particles represented by Ni 0.60 Co 0.20 Mn 0.20 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4) are obtained. Thereafter, a positive electrode active material was obtained and evaluated in the same manner as in Example 3 except that the target addition amount of niobium was 3.2 (molar ratio). The evaluation results are shown in Tables 1 and 2.
- Example 5 The obtained nickel-cobalt-manganese composite hydroxide particles, lithium carbonate, and niobic acid (Nb 2 O 5 .nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed at a molar ratio of nickel: cobalt: manganese: niobium of 58.
- a positive electrode active material was obtained and evaluated in the same manner as in Example 1 except that 0: 18.0: 18.0: 6.0 and Li / Me was measured to be 1.03. The evaluation results are shown in Tables 1 and 2.
- Example 1 The obtained nickel-cobalt-manganese composite hydroxide particles and lithium carbonate have a nickel: cobalt: manganese: niobium molar ratio of 60.0: 20.0: 20.0: 0.0, and Li / Me is 1.
- a positive electrode active material was obtained and evaluated in the same manner as in Example 1 except that it was weighed to 03. The evaluation results are shown in Tables 1 and 2.
- Example 6 (Crystallization process) A predetermined amount of pure water was put into a reaction tank (60 L), and the temperature in the tank was set to 45 ° C. while stirring. At this time, N 2 gas was allowed to flow into the reaction tank, and the dissolved oxygen concentration in the reaction tank liquid was adjusted to 1.5 mg / L. A 2.0M mixed aqueous solution of nickel sulfate, cobalt sulfate, and manganese sulfate, and 25% by mass sodium hydroxide as an alkaline solution so that the molar ratio of nickel: cobalt: manganese in the reaction vessel is 80:10:10. The solution and 25% by mass aqueous ammonia as a complexing agent were simultaneously and continuously added to the reaction vessel.
- the flow rate was controlled so that the residence time of the mixed aqueous solution was 8 hours, the pH in the reaction vessel was adjusted to 11.8 to 12.1, and the ammonia concentration was adjusted to 12 to 13 g / L.
- a slurry containing nickel cobalt manganese composite hydroxide was recovered from the overflow port, followed by filtration to obtain a nickel cobalt manganese composite hydroxide cake (crystallization step). Thereafter, impurities were washed by passing 1 L of pure water through 140 g of nickel cobalt manganese composite hydroxide in the filtered Denver.
- the powder after washing was dried to obtain nickel cobalt manganese composite hydroxide particles represented by Ni 0.80 Co 0.10 Mn 0.10 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4).
- the obtained composite hydroxide had a volume average particle size MV of 10.0 ⁇ m.
- Example 7 (Crystallization process) In the same manner as in the crystallization step of Example 6, nickel cobalt manganese composite hydroxide particles represented by Ni 0.80 Co 0.10 Mn 0.10 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4) were used. Obtained. (Niobium coating process) Next, niobic acid (Nb 2 O 5 ⁇ nH 2 O) powder was kept constant at 80 ° C. in a caustic potash solution having a concentration of 300 g / L so that the niobium concentration was 30 g / L, and stirred for 2 hours. After dissolution, the residue was filtered to prepare a niobium salt solution.
- a niobium salt solution and a 25% by mass sulfuric acid aqueous solution are simultaneously added dropwise to a slurry obtained by mixing the nickel cobalt manganese composite hydroxide with pure water so that the pH is 8.0 while maintaining the solution temperature at 25 ° C.
- a nickel-cobalt composite hydroxide coated with was obtained.
- the target addition amount of niobium was 2.5 (molar ratio).
- Li / Me The atomic ratio (hereinafter referred to as Li / Me) of the obtained niobium-coated nickel-cobalt-manganese composite hydroxide particles and lithium hydroxide to the total metal content of lithium, nickel, cobalt, manganese, and niobium is 1.02.
- Example 6 After being weighed as described above, the mixture was sufficiently mixed using a shaker mixer apparatus (TURBULA Type T2C manufactured by Willy et Bacofen (WAB)) to obtain a lithium mixture. After the firing step, the same procedure as in Example 6 was performed, and a positive electrode active material was obtained and evaluated. The evaluation results are shown in Table 3 and Table 4.
- Example 8 The obtained nickel-cobalt-manganese composite hydroxide particles, lithium hydroxide, and niobic acid (Nb 2 O 5 .nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed in a molar ratio of nickel: cobalt: manganese: niobium.
- the positive electrode active material was weighed so that the Li / Me was 1.02 and 77.5: 9.7: 9.6: 3.2.
- the evaluation results are shown in Table 3 and Table 4.
- Example 6 Was obtained and evaluated in the same manner as in Example 6, except that the weight was 79.3: 10.0: 9.7: 1.0 and Li / Me was 1.02. The evaluation results are shown in Table 3 and Table 4.
- Comparative Example 8 The obtained nickel-cobalt-manganese composite hydroxide particles, lithium hydroxide, and niobic acid (Nb 2 O 5 .nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed in a molar ratio of nickel: cobalt: manganese: niobium.
- a positive electrode active material was obtained and evaluated in the same manner as in Example 6 except that it was weighed so as to be 73.3: 9.0: 9.2: 8.5. The evaluation results are shown in Table 3 and Table 4.
- Example 9 (Crystallization process) A predetermined amount of pure water was put into a reaction tank (60 L), and the temperature in the tank was set to 42 ° C. while stirring. At this time, N 2 gas was allowed to flow into the reaction vessel, and the dissolved oxygen concentration in the reaction vessel liquid was adjusted to 0.6 mg / L. A 2.0M mixed aqueous solution of nickel sulfate, cobalt sulfate, and manganese sulfate, and 25% by mass sodium hydroxide as an alkaline solution so that the molar ratio of nickel: cobalt: manganese in the reaction vessel is 35:35:30. The solution and 25% by mass aqueous ammonia as a complexing agent were simultaneously and continuously added to the reaction vessel.
- the flow rate was controlled so that the residence time of the mixed aqueous solution was 8 hours, the pH in the reaction vessel was adjusted to 11.8 to 12.1, and the ammonia concentration was adjusted to 12 to 13 g / L.
- a slurry containing nickel cobalt manganese composite hydroxide was recovered from the overflow port, followed by filtration to obtain a nickel cobalt manganese composite hydroxide cake (crystallization step). Thereafter, impurities were washed by passing 1 L of pure water through 140 g of nickel cobalt manganese composite hydroxide in the filtered Denver.
- the powder after washing was dried to obtain nickel cobalt manganese composite hydroxide particles represented by Ni 0.35 Co 0.35 Mn 0.30 (OH) 2 + ⁇ (0 ⁇ ⁇ ⁇ 0.4).
- the obtained composite hydroxide had a volume average particle size MV of 10.2 ⁇ m.
- Nithium niobium mixing process The obtained nickel-cobalt-manganese composite hydroxide particles, lithium carbonate, and niobic acid (Nb 2 O 5 ⁇ nH 2 O) having an average particle diameter of 1.0 ⁇ m were mixed in a molar ratio of nickel: cobalt: manganese: niobium. 33.8: 34.2: 29.6: 2.5, and the atomic ratio between the amount of lithium (Li) and the total amount of metal of nickel, cobalt, manganese and niobium (Me) (hereinafter referred to as Li / Me and (Represented) was 1.07.
- the mixture was sufficiently mixed using a shaker mixer device (TURBULA Type T2C manufactured by Willy et Bacofen (WAB)) to obtain a lithium mixture.
- TURBULA Type T2C manufactured by Willy et Bacofen (WAB)
- the obtained lithium mixture was calcined by holding at 940 ° C. for 10 hours in an air stream (oxygen: 21% by volume), and then pulverized to obtain a positive electrode active material comprising a lithium nickel cobalt manganese niobium composite oxide. It was.
- the evaluation results are shown in Table 5 and Table 6.
- (Evaluation results) 9 to 11 are diagrams showing the influence of the niobium content on the discharge capacity and oxygen generation amount after 500 cycles for the positive electrode active materials obtained in Examples and Comparative Examples.
- 9 shows an atomic ratio of Ni: Mn: Co (element M) of 6: 2: 2
- FIG. 10 shows an atomic ratio of Ni: Mn: Co (element M) of 8: 1: 1
- the atomic ratio of Ni: Mn: Co (element M) is 1: 1: 1 (however, the above-mentioned atomic ratio is a ratio calculated using a numerical value rounded off to two decimal places in the general formula (1)).
- the evaluation results are shown in the case of a positive electrode active material represented by the same formula) and manufactured under the same conditions except for the addition amount of Nb.
- the positive electrode active materials obtained in the examples have extremely good durability as compared with Comparative Examples 1, 6, and 9 in which niobium is not added. And excellent in thermal stability.
- the durability discharge capacity after 500 cycles and capacity retention rate
- the positive electrode active material obtained in the examples has a crystallite diameter of (003) plane within a target range (50 to 130 nm), which affects both good electrochemical characteristics and thermal stability. It is estimated that
- Nb was dissolved in the primary particles, and the presence of the lithium niobium compound was confirmed. Therefore, it is presumed that Nb is dissolved in the primary particles, thereby suppressing oxygen release suppression and structural phase transition during overcharge and contributing to thermal stability. Furthermore, the lithium niobium compound present on the surface of the primary particles has high lithium ion conductivity and is chemically stable, so that the electrochemical properties are maintained without degrading the active material, resulting in excellent results. Presumed to have contributed to durability.
- Comparative Example 4 since the firing temperature is high, the initial capacity is low due to the progress of sintering / aggregation and the occurrence of cation mixing. Furthermore, the durability was low due to cation mixing and an increase in the crystallite size of the (003) plane. In Comparative Example 5, since the firing temperature was low, crystal growth did not proceed sufficiently, Nb remained alone and hardly dissolved in the crystal structure, and the concentration difference between the particle surface and the central part was large. For this reason, reaction resistance and bulk resistance became extremely high, and capacity and durability deteriorated. In addition, since the battery capacity is low, it is estimated that the thermal stability is apparently good as in Comparative Example 3.
- the addition method of Nb may be any of solid phase addition (for example, Examples 1 and 2) and coat (for example, Examples 3 and 4).
- niobium is preferably coated (coated) by the niobium coating step (step S13), and the coating has a slightly higher thermal stability improvement effect than solid phase addition.
- solid phase addition lithium niobium mixing step, step S12
- step S12 solid phase addition
- a positive electrode active material for a non-aqueous electrolyte secondary battery that achieves both high capacity, durability, and thermal stability can be obtained by an industrial manufacturing method.
- This non-aqueous electrolyte secondary battery can be suitably used as a power source for small portable electronic devices (such as notebook personal computers and mobile phone terminals) that always require high capacity and long life.
- the secondary battery of the present embodiment is excellent in thermal stability, and has a higher capacity and durability in comparison with a battery using a positive electrode active material of a conventional lithium cobalt oxide or lithium nickel oxide. Excellent in terms of sex. For this reason, it is possible to reduce the size and extend the life of the battery, and therefore it can be suitably used as a power source for an electric vehicle that is restricted by a mounting space.
- the positive electrode active material and the secondary battery using the positive electrode material according to the present embodiment are not only a power source for an electric vehicle driven purely by electric energy but also a so-called hybrid vehicle used in combination with a combustion engine such as a gasoline engine or a diesel engine. It can also be used as a power source or a stationary storage battery.
- SYMBOLS 10 Positive electrode active material 1 ... Primary particle 2 ... Secondary particle 3 ... Lithium metal complex oxide 4 ... Lithium niobium compound CBA ... Coin type battery PE ... Positive electrode (evaluation electrode) NE ... Negative electrode SE ... Separator GA ... Gasket WW ... Wave washer PC ... Positive electrode can NC ... Negative electrode can LBA ... Laminated battery (laminate cell) PS ... Positive electrode sheet NS ... Negative electrode sheet SE2 ... Separator AS ... Aluminum laminate sheet TL ... Tab lead
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Composite Materials (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
数式(1):E=4πS/L2(式中、Sは二次粒子の投影面積であり、Lは二次粒子の周長であり、πは円周率である。)
図1(A)~図1(C)は、本実施形態に係る非水系電解質二次電池用正極活物質(以下、「正極活物質10」ともいう。)の一例を示した図である。正極活物質10は、多結晶構造の粒子で構成される。正極活物質10は、複数の一次粒子1が凝集した二次粒子2で構成されたリチウムニッケルマンガン複合酸化物3(以下、「リチウム金属複合酸化物3」ともいう。)と、リチウムニオブ化合物4と、を含む。
数式(1):E=4πS/L2
(上記式(1)中、Sは二次粒子の投影面積、Lは二次粒子の周長、及びπは円周率である。)
図2~5は、本実施形態の非水系電解質二次電池用正極活物質(以下、「正極活物質」ともいう。)の製造方法の一例を示す図である。本実施形態の製造方法により、上述したような複数の一次粒子1が凝集した二次粒子2で構成され、ニオブの少なくとも一部が、一次粒子1に固溶しているリチウム金属複合酸化物3と、一次粒子1の表面に存在するリチウムニオブ化合物4と、を含む正極活物質を工業的規模で容易に得ることができる。
まず、ニッケルマンガン複合水酸化物粒子(以下、「複合水酸化物粒子」ともいう。)と、ニオブ化合物と、リチウム化合物と、を含むリチウムニオブ混合物を調製する(ステップS10)。リチウムニオブ混合物は、例えば、複合水酸化物粒子に、ニオブ化合物を、リチウム化合物とともに、粉末(固相)で添加し、混合して得てもよい(図3参照)。また、リチウムニオブ混合物は、例えば、複合水酸化物粒子と水と混合して得られたスラリーに、ニオブ塩溶液と酸とを同時に添加して、ニオブ化合物で被覆された複合酸化物粒子を得た後、リチウム化合物を混合して得てもよい(図4参照)。以下、ニオブ混合工程(ステップS10)の詳細について説明する。
晶析工程(ステップS11)は、上記マンガンの含有量を有する複合水酸化物粒子が得られるものであれば公知の方法により行うことができ、例えば、反応槽内において、少なくともニッケルとマンガンとを含む混合水溶液を、一定速度にて攪拌しながら、中和剤を加えて、中和することによりpHを制御して、複合水酸化物粒子を共沈殿により生成させることができる。
リチウムニオブ混合工程(ステップS12)は、上記で得られた複合水酸化物粒子と、ニオブ化合物と、リチウム化合物とを混合してリチウムニオブ混合物を得る工程である。
ニオブ被覆工程(ステップS13)は、晶析工程(ステップS11)で得られた複合水酸化物粒子にニオブ化合物を被覆する工程である。ニオブ化合物の被覆は、例えば、複合水酸化物粒子と、水とを混合して得られたスラリーに、ニオブ塩溶液と酸とを添加して、複合水酸化物粒子の表面にニオブ化合物(例えば、ニオブ水酸化物など)を晶析させることにより行う。なお、このようなニオブ被覆複合水酸化物粒子の製造方法については、例えば、国際公開第2014/034430号などに記載されており、詳細な条件については、これらの文献などを参照して、適宜調整することができる。
リチウム混合工程(ステップS14)は、上述のニオブ化合物で被覆された複合水酸化物粒子と、リチウム化合物と、を混合して、リチウムニオブ混合物を得る工程である。本工程で用いられるリチウム化合物は、上記リチウムニオブ混合工程(ステップS12)と同様のものを用いることができる。また、ニオブ化合物で被覆された複合水酸化物粒子と、リチウム化合物との混合も、上記リチウムニオブ混合工程(ステップS12)と同様の条件で行うことができる。
図5に示すように、本実施形態の製造方法は、上述の混合工程(ステップS12及びステップS14)の前に、複合水酸化物粒子又はニオブ被覆複合水酸化物粒子を熱処理する工程(ステップS16)を含んでもよい。熱処理工程(ステップS16)は、複合水酸化物粒子に含まれる水分の少なくとも一部を熱処理により除去する工程である。複合水酸化物粒子中に残留する水分の少なくとも一部を除去することにより、焼成工程(ステップS20)で得られる正極活物質のLi/Meのばらつくことを防ぐことができる。
焼成工程(ステップS20)は、リチウムニオブ混合物を酸化雰囲気中750℃以上1000℃以下で焼成する工程である。リチウムニオブ混合物を焼成すると、複合水酸化物粒子(図3参照)、又は、後述するニオブ被覆複合水酸化物粒子(図4参照)にリチウム化合物中のリチウムが拡散するので、多結晶構造の粒子からなるリチウム金属複合酸化物3が形成される。リチウム化合物は、焼成時の温度で溶融し、複合水酸化物粒子内に浸透してリチウム金属複合酸化物3を形成する。この際、ニオブ化合物は、まず、溶融したリチウム化合物とともに二次粒子内部まで浸透し、一次粒子間においても結晶粒界などがあれば浸透する。ニオブ化合物が、二次粒子内部や一次粒子間の結晶粒界に浸透することで、一次粒子内部におけるニオブの拡散が促進され、ニオブが一次粒子内で均一に固溶する。本実施形態に係る製造方法では、添加するニオブ量が、一次粒子内への固溶限界を越えるため、余剰のリチウム分と反応し、リチウムニオブ化合物が、一次粒子表面や粒界、あるいは単体で形成される。
本実施形態の非水系電解質二次電池(以下、「二次電池」ともいう。)は、上述の正極活物質を正極に用いる。以下、本実施形態の二次電池の一例について、構成要素ごとにそれぞれ説明する。本実施形態の二次電池は、正極、負極及び非水電解液を含み、一般のリチウムイオン二次電池と同様の構成要素から構成される。なお、以下で説明する実施形態は例示に過ぎず、非水系電解質二次電池は、下記実施形態をはじめとして、当業者の知識に基づいて種々の変更、改良を施した形態で実施することができる。また、二次電池は、その用途を特に限定するものではない。
上記の正極活物質を用いて、二次電池の正極を作製する。以下に正極の製造方法の一例を説明する。まず、上記の正極活物質(粉末状)、導電材および結着剤(バインダー)を混合し、さらに必要に応じて活性炭や、粘度調整などの目的の溶剤を添加し、これを混練して正極合材ペーストを作製する。
負極は、金属リチウム、リチウム合金等を用いることができる。また、負極は、リチウムイオンを吸蔵・脱離できる負極活物質に結着剤を混合し、適当な溶剤を加えてペースト状にした負極合材を、銅等の金属箔集電体の表面に塗布、乾燥し、必要に応じて電極密度を高めるべく圧縮して形成したものを用いてもよい。
正極と負極との間には、セパレータを挟み込んで配置する。セパレータは、正極と負極とを分離し、電解質を保持するものであり、公知のものを用いることができ、例えば、ポリエチレンやポリプロピレンなどの薄い膜で、微少な孔を多数有する膜を用いることができる。
非水系電解液は、支持塩としてのリチウム塩を有機溶媒に溶解したものである。有機溶媒としては、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネートおよびトリフルオロプロピレンカーボネートなどの環状カーボネート、また、ジエチルカーボネート、ジメチルカーボネート、エチルメチルカーボネートおよびジプロピルカーボネートなどの鎖状カーボネート、さらに、テトラヒドロフラン、2-メチルテトラヒドロフランおよびジメトキシエタンなどのエーテル化合物、エチルメチルスルホンやブタンスルトンなどの硫黄化合物、リン酸トリエチルやリン酸トリオクチルなどのリン化合物などから選ばれる1種を単独、又は2種以上を混合して用いることができる。
以上のように説明してきた正極、負極、セパレータおよび非水系電解液で構成される本実施形態の非水系電解質二次電池は、円筒形や積層形など、種々の形状にすることができる。いずれの形状を採る場合であっても、正極および負極を、セパレータを介して積層させて電極体とし、得られた電極体に、非水系電解液を含浸させ、正極集電体と外部に通ずる正極端子との間、および、負極集電体と外部に通ずる負極端子との間を、集電用リードなどを用いて接続し、電池ケースに密閉して、非水系電解質二次電池を完成させる。
本実施形態に係る二次電池は、高い電池容量及び耐久性と、過充電時における酸素放出抑制による高い熱安定性とを両立できる。また、本実施形態に係る二次電池に用いられる正極活物質は、上記のような工業的な製造方法で得ることができる。よって、本実施形態に係る二次電池は、常に高容量を要求される小型携帯電子機器(ノート型パーソナルコンピュータや携帯電話端末など)の電源や、電気自動車用電源、ハイブリッド車用の電源などに好適に用いることができる。
(1)組成の分析
得られたニッケルマンガン複合水酸化物及び正極活物質の組成は、ICP発光分析法により測定した。
(2)平均粒径MV
平均粒径(体積平均粒径MV)の測定は、レーザー回折散乱式粒度分布測定装置(日機装株式会社製、マイクロトラックHRA)により行なった。
(3)結晶子径及びリチウムニオブ化合物の検出
XRD回折装置(パナリティカル社製、X‘Pert PRO)を用いて、得られた正極活物質の結晶構造と、リチウムニオブ化合物の定性評価を行った。また、003結晶子径は、XRD測定結果から、2θ=18°付近に存在する(003)面のピークの解析を行い、Scherrerの式を用いて算出した。
(4)ニオブ濃度
正極活物質をS-TEMによる一次粒子の断面分析が可能となるように加工した。正極活物質に含まれる複数の二次粒子から任意に30個の一次粒子を選択し、個々の一次粒子断面内をS-TEMのEDXにより組成を線分析した。その際に、線分析の方向は、事前に面分析して一次粒子の表面のニオブ化合物の存在により一次粒子の表面付近のニオブ濃度の計測値が影響されない方向で、かつ当該一次粒子の最大長の50%以上の長さで分析できる方向を選択した。線分析によって得られたニオブ濃度の計測値から、最大ニオブ濃度と一次粒子内の平均ニオブ濃度を求め、個々の一次粒子の最大ニオブ濃度の比をそれぞれ算出し、さらに各一次粒子から算出される最大ニオブ濃度の比を個数平均することにより正極活物質の最大ニオブ濃度の比を求めた。
初期充電容量及び初期放電容量は、図7に示すコイン型電池CBAを作製してから24時間程度放置し、開回路電圧OCV(open circuit voltage)が安定した後、正極に対する電流密度を0.1mA/cm2としてカットオフ電圧4.3Vまで充電して初期充電容量とし、1時間の休止後、カットオフ電圧3.0Vまで放電したときの容量を初期放電容量とした。放電容量の測定には,マルチチャンネル電圧/電流発生器(株式会社アドバンテスト製、R6741A)を用いた。
正極活物質のガス発生量の評価には、図8に示すラミネート型電池LBAを使用した。
正極の熱安定性評価は、正極活物質を過充電状態とし、加熱することで放出される酸素量の定量により行った。(5)と同様のコイン型電池CBAを作製し、カットオフ電圧4.5Vまで0.2CレートでCCCV充電(定電流―定電圧充電)した。その後、コイン電池を解体し、短絡しないよう慎重に正極のみ取り出して、DMC(ジメチルカーボネート)で洗浄し、乾燥した。乾燥後の正極をおよそ2mg量りとり、ガスクロマトグラフ質量分析計(GCMS、島津製作所、QP-2010plus)を用いて、昇温速度10℃/minで室温から450℃まで昇温した。キャリアガスにはヘリウムを用いた。加熱時に発生した酸素(m/z=32)の発生挙動を測定し、得られた最大酸素発生ピーク高さ(強度)とピーク面積から酸素発生量の半定量を行い、これらを熱安定性の評価指標とした。なお、酸素発生量の半定量値は、純酸素ガスを標準試料としてGCMSに注入し、その測定結果から得た検量線を外挿して算出した。
(晶析工程)
反応槽(60L)に純水を所定量入れ、攪拌しながら槽内温度を45℃に設定した。このとき反応槽内にN2ガスを流し、反応槽液中の溶存酸素濃度が0.8mg/Lとなるように調整した。この反応槽内のニッケル:コバルト:マンガンのモル比が60:20:20となるように、硫酸ニッケル、硫酸コバルト、硫酸マンガンの2.0Mの混合水溶液と、アルカリ溶液として25質量%水酸化ナトリウム溶液と、錯化剤として25質量%アンモニア水と、を反応槽に同時に連続的に添加した。このとき、混合水溶液の滞留時間が8時間となるように流量を制御し、反応槽内のpHを11.8~12.1に、アンモニア濃度を12~13g/Lに調整した。反応槽内が安定した後、オーバーフロー口からニッケルコバルトマンガン複合水酸化物を含むスラリーを回収し、その後、濾過を行い、ニッケルコバルトマンガン複合水酸化物のケーキを得た(晶析工程)。その後、濾過を行ったデンバー内にあるニッケルコバルトマンガン複合水酸化物140gに対して1Lの純水を通液することで、不純物の洗浄を行った。洗浄後の粉を乾燥し、Ni0.60Co0.20Mn0.20(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た。得られた複合水酸化物の平均粒径MVは、9.9μmであった。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とを、ニッケル:コバルト:マンガン:ニオブのモル比が59.1:19.2:19.2:2.5になるように、かつ、リチウム量(Li)とニッケル、コバルト、マンガン及びニオブの合計メタル量(Me)との原子比(以下、Li/Meと表す)が1.03になるように、秤量した。その後、シェーカーミキサー装置(ウィリー・エ・バッコーフェン(WAB)社製TURBULA TypeT2C)を用いて十分に混合し、リチウム混合物を得た。
得られたリチウム混合物を空気(酸素:21容量%)気流中にて900℃で10時間保持して焼成し、その後、解砕してリチウムニッケルコバルトマンガンニオブ複合酸化物かなる正極活物質を得た。
得られた正極活物質を用いた二次電池の初期特性評価(初期充放電容量)、耐久性評価、及び、熱安定性評価をそれぞれ上述の方法で行った。これらの評価結果を表2に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とをニッケル:コバルト:マンガン:ニオブのモル比が58.8:19.0:19.0:3.2になるように秤量したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
(晶析工程)
実施例1の晶析工程と同様にして、Ni0.60Co0.20Mn0.20(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た。
(ニオブ被覆工程)
次いで、ニオブ酸(Nb2O5・nH2O)粉末を300g/Lの濃度の苛性カリ溶液にニオブ濃度で30g/Lとなるように、溶解温度を80℃で一定に保持し、2時間攪拌して溶解した後、残渣を濾別してニオブ塩溶液作製した。上記ニッケルコバルトマンガン複合水酸化物を純水と混合したスラリーにニオブ塩溶液と25質量%硫酸水溶液を、液温25℃で保持しながらpHが8.0となるように同時に滴下し、ニオブ化合物で被覆されたニッケルコバルト複合水酸化物を得た。なお、狙いのニオブ添加量は2.5(モル比)とした。
(リチウム混合工程、焼成工程)
得られたニオブ被覆ニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムをリチウムとニッケル、コバルト、マンガン、ニオブの合計メタル量との原子比(以下、Li/Meと表す)が1.03となるように秤量した後、シェーカーミキサー装置(ウィリー・エ・バッコーフェン(WAB)社製TURBULA TypeT2C)を用いて十分に混合し、リチウム混合物を得た。焼成工程以降は実施例1と同様とし、正極活物質を得るとともに評価した。評価結果を表1および2に示す。
実施例1の晶析工程と同様にしてNi0.60Co0.20Mn0.20(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た後、狙いのニオブ添加量を3.2(モル比)としたこと以外は、実施例3と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウム、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)をニッケル:コバルト:マンガン:ニオブのモル比が58.0:18.0:18.0:6.0、かつ、Li/Meが1.03となるように秤量したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と炭酸リチウムをニッケル:コバルト:マンガン:ニオブのモル比が60.0:20.0:20.0:0.0、かつ、Li/Meが1.03となるように秤量したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
[比較例2]
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウム、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)をニッケル:コバルト:マンガン:ニオブのモル比が59.6:19.7:19.7:1.0、かつ、Li/Meが1.03となるように秤量したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。また、得られた正極活物質のSEM像を図4に示す。
[比較例3]
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウム、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)をニッケル:コバルト:マンガン:ニオブのモル比が57.1:17.2:17.2:8.5、かつ、Li/Meが1.03となるように秤量したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
[比較例4]
リチウム混合物を空気(酸素:21容量%)気流中にて1020℃で10時間保持焼成したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
[比較例5]
リチウム混合物を空気(酸素:21容量%)気流中にて700℃で10時間保持焼成したこと以外は実施例1と同様に正極活物質を得るとともに評価した。評価結果を表1および2に示す。
(晶析工程)
反応槽(60L)に純水を所定量入れ、攪拌しながら槽内温度を45℃に設定した。このとき反応槽内にN2ガスを流し、反応槽液中の溶存酸素濃度が1.5mg/Lとなるように調整した。この反応槽内のニッケル:コバルト:マンガンのモル比が80:10:10となるように、硫酸ニッケル、硫酸コバルト、硫酸マンガンの2.0Mの混合水溶液と、アルカリ溶液として25質量%水酸化ナトリウム溶液と、錯化剤として25質量%アンモニア水と、を反応槽に同時に連続的に添加した。このとき、混合水溶液の滞留時間が8時間となるように流量を制御し、反応槽内のpHを11.8~12.1に、アンモニア濃度を12~13g/Lに調整した。反応槽内が安定した後、オーバーフロー口からニッケルコバルトマンガン複合水酸化物を含むスラリーを回収し、その後、濾過を行い、ニッケルコバルトマンガン複合水酸化物のケーキを得た(晶析工程)。その後、濾過を行ったデンバー内にあるニッケルコバルトマンガン複合水酸化物140gに対して1Lの純水を通液することで、不純物の洗浄を行った。洗浄後の粉を乾燥し、Ni0.80Co0.10Mn0.10(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た。得られた複合水酸化物の体積平均粒径MVは、10.0μmであった。
得られたニッケルコバルトマンガン複合水酸化物粒子と、水酸化リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とを、ニッケル:コバルト:マンガン:ニオブのモル比が78.0:9.8:9.4:2.5、かつ、リチウム量(Li)とニッケル、コバルト、マンガン及びニオブの合計メタル量(Me)との原子比(以下、Li/Meと表す)が1.02となるように、秤量した。その後、シェーカーミキサー装置(ウィリー・エ・バッコーフェン(WAB)社製TURBULA TypeT2C)を用いて十分に混合し、リチウム混合物を得た。
得られたリチウム混合物を酸素気流中にて870℃で10時間保持して焼成し、その後、解砕してリチウムニッケルコバルトマンガンニオブ複合酸化物かなる正極活物質を得た。評価結果を表3および表4に示す。
(晶析工程)
実施例6の晶析工程と同様にして、Ni0.80Co0.10Mn0.10(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た。
(ニオブ被覆工程)
次いで、ニオブ酸(Nb2O5・nH2O)粉末を300g/Lの濃度の苛性カリ溶液にニオブ濃度で30g/Lとなるように、溶解温度を80℃で一定に保持し、2時間攪拌して溶解した後、残渣を濾別してニオブ塩溶液作製した。上記ニッケルコバルトマンガン複合水酸化物を純水と混合したスラリーにニオブ塩溶液と25質量%硫酸水溶液を、液温25℃で保持しながらpHが8.0となるように同時に滴下し、ニオブ化合物で被覆されたニッケルコバルト複合水酸化物を得た。なお、狙いのニオブ添加量は2.5(モル比)とした。
(リチウム混合工程、焼成工程)
得られたニオブ被覆ニッケルコバルトマンガン複合水酸化物粒子と、水酸化リチウムをリチウムとニッケル、コバルト、マンガン、ニオブの合計メタル量との原子比(以下、Li/Meと表す)が1.02になるように秤量した後、シェーカーミキサー装置(ウィリー・エ・バッコーフェン(WAB)社製TURBULA TypeT2C)を用いて十分に混合し、リチウム混合物を得た。焼成工程以降は実施例6と同様とし、正極活物質を得るとともに評価した。評価結果を表3および表4に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と、水酸化リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とをニッケル:コバルト:マンガン:ニオブのモル比が77.5:9.7:9.6:3.2、かつ、Li/Meが1.02となるように秤量したこと以外は実施例6と同様に正極活物質を得るとともに評価した。評価結果を表3および表4に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と炭酸リチウムをニッケル:コバルト:マンガンのモル比が80.0:10.0:10.0かつ、Li/Meが1.02となるように秤量したこと以外は実施例6と同様に正極活物質を得るとともに評価した。評価結果を表3および表4に示す。
(比較例7)
得られたニッケルコバルトマンガン複合水酸化物粒子と、水酸化リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とをニッケル:コバルト:マンガン:ニオブのモル比が79.3:10.0:9.7:1.0かつ、Li/Meが1.02となるように秤量したこと以外は実施例6と同様に正極活物質を得るとともに評価した。評価結果を表3および表4に示す。
(比較例8)
得られたニッケルコバルトマンガン複合水酸化物粒子と、水酸化リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とをニッケル:コバルト:マンガン:ニオブのモル比が73.3:9.0:9.2:8.5になるように秤量したこと以外は実施例6と同様に正極活物質を得るとともに評価した。評価結果を表3および表4に示す。
(晶析工程)
反応槽(60L)に純水を所定量入れ、攪拌しながら槽内温度を42℃に設定した。このとき反応槽内にN2ガスを流し、反応槽液中の溶存酸素濃度が0.6mg/Lとなるように調整した。この反応槽内のニッケル:コバルト:マンガンのモル比が35:35:30となるように、硫酸ニッケル、硫酸コバルト、硫酸マンガンの2.0Mの混合水溶液と、アルカリ溶液として25質量%水酸化ナトリウム溶液と、錯化剤として25質量%アンモニア水と、を反応槽に同時に連続的に添加した。このとき、混合水溶液の滞留時間が8時間となるように流量を制御し、反応槽内のpHを11.8~12.1に、アンモニア濃度を12~13g/Lに調整した。反応槽内が安定した後、オーバーフロー口からニッケルコバルトマンガン複合水酸化物を含むスラリーを回収し、その後、濾過を行い、ニッケルコバルトマンガン複合水酸化物のケーキを得た(晶析工程)。その後、濾過を行ったデンバー内にあるニッケルコバルトマンガン複合水酸化物140gに対して1Lの純水を通液することで、不純物の洗浄を行った。洗浄後の粉を乾燥し、Ni0.35Co0.35Mn0.30(OH)2+α(0≦α≦0.4)で表されるニッケルコバルトマンガン複合水酸化物粒子を得た。得られた複合水酸化物の体積平均粒径MVは、10.2μmであった。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とを、ニッケル:コバルト:マンガン:ニオブのモル比が33.8:34.2:29.6:2.5、かつ、リチウム量(Li)とニッケル、コバルト、マンガン及びニオブの合計メタル量(Me)との原子比(以下、Li/Meと表す)が1.07となるように、秤量した。その後、シェーカーミキサー装置(ウィリー・エ・バッコーフェン(WAB)社製TURBULA TypeT2C)を用いて十分に混合し、リチウム混合物を得た。
(焼成工程)
得られたリチウム混合物を空気(酸素:21容量%)気流中にて940℃で10時間保持して焼成し、その後、解砕してリチウムニッケルコバルトマンガンニオブ複合酸化物かなる正極活物質を得た。評価結果を表5および表6に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と炭酸リチウムをニッケル:コバルト:マンガン:ニオブのモル比が35.0:30.0:35.0:0.0、かつ、Li/Meが1.07となるように秤量したこと以外は実施例9と同様に正極活物質を得るとともに評価した。評価結果を表5および表6に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とを、ニッケル:コバルト:マンガン:ニオブのモル比が34.4:34.7:29.9:1.0、かつ、Li/Meが1.07となるように秤量したこと以外は実施例9と同様に正極活物質を得るとともに評価した。評価結果を表5および表6に示す。
得られたニッケルコバルトマンガン複合水酸化物粒子と、炭酸リチウムと、平均粒径が1.0μmのニオブ酸(Nb2O5・nH2O)とをニッケル:コバルト:マンガン:ニオブのモル比が31.7:32.1:27.7:8.5、かつ、Li/Meが1.07となるように秤量したこと以外は実施例9と同様に正極活物質を得るとともに評価した。評価結果を表5および表6に示す。
図9~11は、実施例及び比較例で得られた正極活物質について、ニオブの含有量による、500サイクル後の放電容量及び酸素発生量への影響について示した図である。図9は、Ni:Mn:Co(元素M)の原子比が6:2:2、図10は、Ni:Mn:Co(元素M)の原子比が8:1:1、図11は、Ni:Mn:Co(元素M)の原子比が1:1:1(ただし、上記の原子比は、一般式(1)において、小数点以下2桁四捨五入した数値を用いて算出した比である。)で表される正極活物質であって、かつ、Nbの添加量以外は、同じ条件で製造した場合のそれぞれの評価結果を示している。
1…一次粒子
2…二次粒子
3…リチウム金属複合酸化物
4…リチウムニオブ化合物
CBA…コイン型電池
PE…正極(評価用電極)
NE…負極
SE…セパレータ
GA…ガスケット
WW…ウェーブワッシャー
PC…正極缶
NC…負極缶
LBA…ラミネート型電池(ラミネートセル)
PS…正極シート
NS…負極シート
SE2…セパレータ
AS…アルミラミネートシート
TL…タブリード
Claims (11)
- 複数の一次粒子が凝集した二次粒子で構成されたリチウムニッケルマンガン複合酸化物と、リチウムニオブ化合物と、を含む非水系電解質二次電池用正極活物質であって、
前記正極活物質は、一般式(1):LidNi1-a-b-cMnaMbNbcO2+γ(前記一般式(1)中、Mは、Co、W、Mo、V、Mg、Ca、Al、Ti、Cr、Zr及びTaから選択される少なくとも1種の元素であり、0.03≦a≦0.60、0≦b≦0.60、0.02≦c≦0.08、a+b+c<1、0.95≦d≦1.20、0≦γ≦0.5である。)で表され、
前記リチウムニッケルマンガン複合酸化物は、(003)面の結晶子径が50nm以上130nm以下であり、
前記リチウムニオブ化合物は、前記一次粒子表面に存在し、かつ、
前記正極活物質中のニオブの一部は、前記一次粒子に固溶する、
非水系電解質二次電池用正極活物質。 - 前記リチウムニオブ化合物は、Li3NbO4、LiNbO3、Li5NbO5、LiNb3O8及びLi8Nb2O9の少なくとも一つを含む、請求項1に記載の非水系電解質二次電池用正極活物質。
- 前記リチウムニオブ化合物は、アモルファス相を含む、請求項1又は請求項2に記載の非水系電解質二次電池用正極活物質。
- 前記正極活物質の体積平均粒径MVが5μm以上20μm以下である、請求項1~3のいずれか一項に記載の非水系電解質二次電池用正極活物質。
- 下記数式(1)で求められる前記二次粒子の円形度Eの平均が0.60以上0.98以下である、請求項1~4のいずれか一項に記載の非水系電解質二次電池用正極活物質。
数式(1):E=4πS/L2
(前記式中、Sは二次粒子の投影面積であり、Lは二次粒子の周長であり、πは円周率である。) - 複数の一次粒子が凝集した二次粒子で構成されたリチウムニッケルマンガン複合酸化物と、リチウムニオブ化合物と、を含む非水系電解質二次電池用の正極活物質の製造方法であって、
一般式(2):Ni1-a-bMnaMb(OH)2+α(前記式(2)中、Mは、Co、W、Mo、V、Mg、Ca、Al、Ti、Cr、Zr及びTaから選択される少なくとも1種の元素であり、0.03≦a≦0.60、0≦b≦0.60、0≦α≦0.4である。)で表されるニッケルマンガン複合水酸化物粒子と、ニオブ化合物と、リチウム化合物とを含むリチウムニオブ混合物を調製するニオブ混合工程と、
前記リチウムニオブ混合物を酸化雰囲気中750℃以上1000℃以下で焼成して、前記リチウムニッケルマンガン複合酸化物と、前記リチウムニオブ化合物とを得る焼成工程と、を備え、
前記正極活物質は、一般式(1):LidNi1-a-b-cMnaMbNbcO2+γ(前記一般式(1)中、Mは、Co、W、Mo、V、Mg、Ca、Al、Ti、Cr、Zr及びTaから選択される少なくとも1種の元素であり、0.03≦a≦0.60、0≦b≦0.60、0.02≦c≦0.08、0.95≦d≦1.20である。)で表され、
前記リチウムニオブ化合物は、前記一次粒子表面に存在し、かつ、
前記正極活物質中のニオブの一部が前記一次粒子に固溶する、
非水系電解質二次電池用正極活物質の製造方法。 - 前記ニオブ混合工程は、
晶析により前記ニッケルマンガン複合水酸化物粒子を得る晶析工程と、
前記ニッケルマンガン複合水酸化物粒子と、前記リチウム化合物と、平均粒径が0.01μm以上10μm以下の前記ニオブ化合物とを混合して、前記リチウムニオブ混合物を調製する第1の混合工程と、
を含む、請求項6に記載の非水系電解質二次電池用正極活物質の製造方法。 - 前記ニオブ化合物は、ニオブ酸及び酸化ニオブのうち少なくとも一方である、請求項6に記載の非水系電解質二次電池用正極活物質の製造方法。
- 前記ニオブ混合工程は、
晶析により前記ニッケルマンガン複合水酸化物粒子を得る晶析工程と、
前記ニッケルマンガン複合水酸化物粒子と、水とを混合して得られたスラリーに、ニオブ塩溶液と酸とを添加して、ニオブ化合物で被覆されたニッケルマンガン複合水酸化物粒子を得るニオブ被覆工程と、
前記ニオブ化合物で被覆されたニッケルマンガン複合水酸化物粒子と、前記リチウム化合物とを混合して前記リチウムニオブ混合物を調製する第2の混合工程と、
を含む、請求項6に記載の非水系電解質二次電池用正極活物質の製造方法。 - 前記リチウムニオブ混合物を調製する前に、前記ニッケルマンガン複合水酸化物粒子を105℃以上700℃以下の温度で熱処理する熱処理工程と、を含み、
前記ニオブ混合工程は、前記熱処理して得られたニッケルマンガン複合水酸化物粒子及びニッケルマンガン複合酸化物粒子のうち少なくとも一方と、ニオブ化合物と、リチウム化合物と、を含むリチウムニオブ混合物を調製する、
請求項6~9のいずれか一項に記載の非水系電解質二次電池用正極活物質の製造方法。 - 正極、負極、及び、非水系電解質を備え、請求項1~4のいずれか一項に記載の非水系電解質二次電池用正極活物質を正極に含む、非水系電解質二次電池。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP17887069.7A EP3561924B1 (en) | 2016-12-26 | 2017-12-25 | Positive electrode active material for non-aqueous electrolyte secondary cell and method for manufacturing same, and non-aqueous electrolyte secondary cell |
JP2018559446A JP7176412B2 (ja) | 2016-12-26 | 2017-12-25 | 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 |
US16/473,045 US11735726B2 (en) | 2016-12-26 | 2017-12-25 | Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing the same, and nonaqueous electrolyte secondary battery |
CN201780080782.6A CN110392950B (zh) | 2016-12-26 | 2017-12-25 | 非水系电解质二次电池用正极活性物质和其制造方法、和非水系电解质二次电池 |
KR1020197017902A KR102603503B1 (ko) | 2016-12-26 | 2017-12-25 | 비수계 전해질 이차 전지용 정극 활물질과 그의 제조 방법 및 비수계 전해질 이차 전지 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016-252097 | 2016-12-26 | ||
JP2016252097 | 2016-12-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2018123951A1 true WO2018123951A1 (ja) | 2018-07-05 |
Family
ID=62707712
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/046391 WO2018123951A1 (ja) | 2016-12-26 | 2017-12-25 | 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 |
Country Status (6)
Country | Link |
---|---|
US (1) | US11735726B2 (ja) |
EP (1) | EP3561924B1 (ja) |
JP (1) | JP7176412B2 (ja) |
KR (1) | KR102603503B1 (ja) |
CN (1) | CN110392950B (ja) |
WO (1) | WO2018123951A1 (ja) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110718686A (zh) * | 2018-07-11 | 2020-01-21 | 西北大学 | 一种富锂锰基正极材料的制备方法及其前驱体的制备方法 |
JPWO2020027204A1 (ja) * | 2018-08-03 | 2020-08-06 | 住友金属鉱山株式会社 | リチウムイオン二次電池用正極活物質、リチウムイオン二次電池用正極活物質の製造方法、リチウムイオン二次電池 |
WO2020232531A1 (en) * | 2019-05-21 | 2020-11-26 | Nano One Materials Corp. | Stabilized high nickel nmc cathode materials for improved battery performance |
WO2020262100A1 (ja) | 2019-06-28 | 2020-12-30 | パナソニックIpマネジメント株式会社 | 非水電解質二次電池用正極活物質、非水電解質二次電池、及び非水電解質二次電池用正極活物質の製造方法 |
WO2020262101A1 (ja) | 2019-06-28 | 2020-12-30 | パナソニックIpマネジメント株式会社 | 非水電解質二次電池用正極活物質、非水電解質二次電池、及び非水電解質二次電池用正極活物質の製造方法 |
JP2021084856A (ja) * | 2019-11-29 | 2021-06-03 | エコプロ ビーエム カンパニー リミテッドEcopro Bm Co., Ltd. | リチウム複合酸化物およびこれを含むリチウム二次電池 |
JP2021086830A (ja) * | 2019-11-29 | 2021-06-03 | エコプロ ビーエム カンパニー リミテッドEcopro Bm Co., Ltd. | 正極活物質およびこれを含むリチウム二次電池 |
JP7157219B1 (ja) | 2021-08-03 | 2022-10-19 | 住友化学株式会社 | リチウム二次電池用正極活物質、リチウム二次電池用正極及びリチウム二次電池 |
EP3940812A4 (en) * | 2019-03-12 | 2023-01-04 | Kabushiki Kaisha Toshiba | ACTIVE SUBSTANCE, ELECTRODE, SECONDARY BATTERY, BATTERY PACK AND CAR |
US20230187625A1 (en) * | 2019-07-08 | 2023-06-15 | Sumitomo Metal Mining Co., Ltd. | Method for producing positive electrode active material for lithium ion secondary battery |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220158185A1 (en) * | 2019-04-26 | 2022-05-19 | Sumitomo Metal Mining Co., Ltd. | Nickel composite hydroxide, method for producing nickel composite hydroxide, positive electrode active material for lithium ion secondary battery, method for producing positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery |
KR20210021822A (ko) * | 2019-08-19 | 2021-03-02 | 주식회사 엘지화학 | 열처리에 의한 리튬 전지셀 회복방법 및 이를 포함하는 리튬 전지셀의 제조방법 |
KR102316888B1 (ko) * | 2019-12-20 | 2021-10-22 | 주식회사 포스코 | 양극 활물질, 이의 제조 방법, 및 이를 포함하는 리튬 이차 전지 |
WO2021131241A1 (ja) * | 2019-12-24 | 2021-07-01 | パナソニックIpマネジメント株式会社 | 非水電解質二次電池用正極活物質、及び非水電解質二次電池 |
WO2022078980A1 (en) * | 2020-10-15 | 2022-04-21 | Basf Se | Process for making a coated cathode active material |
JP2024522673A (ja) * | 2021-08-11 | 2024-06-21 | 寧徳新能源科技有限公司 | 電気化学装置及び電子装置 |
CN118339669A (zh) | 2021-12-02 | 2024-07-12 | 巴斯夫欧洲公司 | 用于电化学电池的电极的涂覆颗粒材料 |
CN114447296B (zh) * | 2021-12-30 | 2024-05-03 | 江苏当升材料科技有限公司 | 正极材料及其制备方法与应用、锂离子电池 |
CN114715957B (zh) * | 2022-05-12 | 2023-12-29 | 南开大学 | 铌包覆镍钴锰三元前驱体及制备方法及应用 |
CN115084472B (zh) * | 2022-06-30 | 2023-05-26 | 北京当升材料科技股份有限公司 | 表面包覆正极材料及其制备方法、锂离子电池 |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002151071A (ja) | 2000-11-08 | 2002-05-24 | Dowa Mining Co Ltd | 非水系二次電池用正極活物質とその製造方法およびそれを用いた非水系二次電池 |
JP2003068298A (ja) * | 2001-08-24 | 2003-03-07 | Seimi Chem Co Ltd | リチウム含有遷移金属複合酸化物およびその製造方法 |
JP2005251716A (ja) | 2004-02-05 | 2005-09-15 | Nichia Chem Ind Ltd | 非水電解質二次電池用正極活物質、非水電解質二次電池用正極合剤および非水電解質二次電池 |
JP2011108554A (ja) | 2009-11-19 | 2011-06-02 | Mitsubishi Chemicals Corp | リチウム遷移金属系化合物粉体、その製造方法、及びそれを用いたリチウム二次電池用正極及びリチウム二次電池 |
WO2012131881A1 (ja) | 2011-03-28 | 2012-10-04 | 住友金属鉱山株式会社 | ニッケルマンガン複合水酸化物粒子とその製造方法、非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 |
JP2013239434A (ja) | 2012-04-18 | 2013-11-28 | Nichia Chem Ind Ltd | 非水電解液二次電池用正極組成物 |
WO2014034430A1 (ja) | 2012-08-28 | 2014-03-06 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質及びこれを用いた非水系電解質二次電池 |
JP2015072801A (ja) * | 2013-10-03 | 2015-04-16 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質および非水系電解質二次電池 |
WO2015076323A1 (ja) * | 2013-11-22 | 2015-05-28 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質及びその製造方法、並びに非水系電解質二次電池 |
JP2015122298A (ja) | 2013-11-22 | 2015-07-02 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質及びこれを用いた非水系電解質二次電池 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5675128B2 (ja) * | 2009-08-28 | 2015-02-25 | 三洋電機株式会社 | リチウムイオン二次電池 |
JP2011187435A (ja) * | 2010-02-09 | 2011-09-22 | Sanyo Electric Co Ltd | 非水電解質二次電池 |
KR101390533B1 (ko) * | 2010-02-09 | 2014-04-30 | 도요타지도샤가부시키가이샤 | 비수계 전해질 이차 전지용 정극 활성 물질, 그의 제조 방법, 및 상기 정극 활성 물질을 이용한 비수계 전해질 이차 전지 |
US20130059209A1 (en) * | 2010-05-17 | 2013-03-07 | Sumitomo Electric Industries, Ltd. | Positive-electrode body for nonaqueous-electrolyte battery, method for producing the positive-electrode body, and nonaqueous-electrolyte battery |
WO2012121220A1 (ja) | 2011-03-07 | 2012-09-13 | 旭硝子株式会社 | リチウムイオン二次電池用の正極活物質およびその製造方法 |
US10522830B2 (en) * | 2013-11-22 | 2019-12-31 | Sumitomo Metal Mining Co., Ltd. | Positive electrode active material for nonaqueous electrolyte secondary batteries and production method thereof, and nonaqueous electrolyte secondary battery |
JP6340791B2 (ja) * | 2013-12-25 | 2018-06-13 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法 |
JP6142929B2 (ja) | 2014-01-31 | 2017-06-07 | 住友金属鉱山株式会社 | ニッケルマンガン複合水酸化物粒子とその製造方法、非水電解質二次電池用正極活物質とその製造方法、および非水電解質二次電池 |
JP6195118B2 (ja) * | 2014-09-02 | 2017-09-13 | トヨタ自動車株式会社 | 非水電解液二次電池 |
-
2017
- 2017-12-25 KR KR1020197017902A patent/KR102603503B1/ko active IP Right Grant
- 2017-12-25 JP JP2018559446A patent/JP7176412B2/ja active Active
- 2017-12-25 EP EP17887069.7A patent/EP3561924B1/en active Active
- 2017-12-25 WO PCT/JP2017/046391 patent/WO2018123951A1/ja unknown
- 2017-12-25 CN CN201780080782.6A patent/CN110392950B/zh active Active
- 2017-12-25 US US16/473,045 patent/US11735726B2/en active Active
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002151071A (ja) | 2000-11-08 | 2002-05-24 | Dowa Mining Co Ltd | 非水系二次電池用正極活物質とその製造方法およびそれを用いた非水系二次電池 |
JP2003068298A (ja) * | 2001-08-24 | 2003-03-07 | Seimi Chem Co Ltd | リチウム含有遷移金属複合酸化物およびその製造方法 |
JP2005251716A (ja) | 2004-02-05 | 2005-09-15 | Nichia Chem Ind Ltd | 非水電解質二次電池用正極活物質、非水電解質二次電池用正極合剤および非水電解質二次電池 |
JP2011108554A (ja) | 2009-11-19 | 2011-06-02 | Mitsubishi Chemicals Corp | リチウム遷移金属系化合物粉体、その製造方法、及びそれを用いたリチウム二次電池用正極及びリチウム二次電池 |
WO2012131881A1 (ja) | 2011-03-28 | 2012-10-04 | 住友金属鉱山株式会社 | ニッケルマンガン複合水酸化物粒子とその製造方法、非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 |
JP2013239434A (ja) | 2012-04-18 | 2013-11-28 | Nichia Chem Ind Ltd | 非水電解液二次電池用正極組成物 |
WO2014034430A1 (ja) | 2012-08-28 | 2014-03-06 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質及びこれを用いた非水系電解質二次電池 |
JP2015072801A (ja) * | 2013-10-03 | 2015-04-16 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質および非水系電解質二次電池 |
WO2015076323A1 (ja) * | 2013-11-22 | 2015-05-28 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質及びその製造方法、並びに非水系電解質二次電池 |
JP2015122298A (ja) | 2013-11-22 | 2015-07-02 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質及びこれを用いた非水系電解質二次電池 |
Cited By (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110718686A (zh) * | 2018-07-11 | 2020-01-21 | 西北大学 | 一种富锂锰基正极材料的制备方法及其前驱体的制备方法 |
US11894555B2 (en) | 2018-08-03 | 2024-02-06 | Sumitomo Metal Mining Co., Ltd. | Positive electrode active material for lithium ion secondary battery, method of manufacturing positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery |
JPWO2020027204A1 (ja) * | 2018-08-03 | 2020-08-06 | 住友金属鉱山株式会社 | リチウムイオン二次電池用正極活物質、リチウムイオン二次電池用正極活物質の製造方法、リチウムイオン二次電池 |
JP7198777B2 (ja) | 2018-08-03 | 2023-01-04 | 住友金属鉱山株式会社 | リチウムイオン二次電池用正極活物質、リチウムイオン二次電池用正極活物質の製造方法、リチウムイオン二次電池 |
EP3940812A4 (en) * | 2019-03-12 | 2023-01-04 | Kabushiki Kaisha Toshiba | ACTIVE SUBSTANCE, ELECTRODE, SECONDARY BATTERY, BATTERY PACK AND CAR |
US11984588B2 (en) | 2019-03-12 | 2024-05-14 | Kabushiki Kaisha Toshiba | Active material, electrode, secondary battery, battery pack, and vehicle |
JP7295275B2 (ja) | 2019-05-21 | 2023-06-20 | ナノ ワン マテリアルズ コーポレーション | 改善された電池性能のための安定化された高ニッケルnmcカソード材料 |
CN113875045A (zh) * | 2019-05-21 | 2021-12-31 | 加拿大商纳诺万麦帝瑞尔公司 | 用于提高电池性能的稳定的高镍nmc阴极材料 |
JP2022537889A (ja) * | 2019-05-21 | 2022-08-31 | ナノ ワン マテリアルズ コーポレーション | 改善された電池性能のための安定化された高ニッケルnmcカソード材料 |
WO2020232531A1 (en) * | 2019-05-21 | 2020-11-26 | Nano One Materials Corp. | Stabilized high nickel nmc cathode materials for improved battery performance |
CN113994508A (zh) * | 2019-06-28 | 2022-01-28 | 松下知识产权经营株式会社 | 非水电解质二次电池用正极活性物质、非水电解质二次电池及非水电解质二次电池用正极活性物质的制造方法 |
WO2020262101A1 (ja) | 2019-06-28 | 2020-12-30 | パナソニックIpマネジメント株式会社 | 非水電解質二次電池用正極活物質、非水電解質二次電池、及び非水電解質二次電池用正極活物質の製造方法 |
WO2020262100A1 (ja) | 2019-06-28 | 2020-12-30 | パナソニックIpマネジメント株式会社 | 非水電解質二次電池用正極活物質、非水電解質二次電池、及び非水電解質二次電池用正極活物質の製造方法 |
US20230187625A1 (en) * | 2019-07-08 | 2023-06-15 | Sumitomo Metal Mining Co., Ltd. | Method for producing positive electrode active material for lithium ion secondary battery |
JP2022141690A (ja) * | 2019-11-29 | 2022-09-29 | エコプロ ビーエム カンパニー リミテッド | リチウム複合酸化物およびこれを含むリチウム二次電池 |
US11588154B2 (en) | 2019-11-29 | 2023-02-21 | Ecopro Bm Co., Ltd. | Positive electrode active material and lithium secondary battery comprising the same |
US11631849B2 (en) | 2019-11-29 | 2023-04-18 | Ecopro Bm Co., Ltd. | Lithium composite oxide and lithium secondary battery comprising the same |
JP7100102B2 (ja) | 2019-11-29 | 2022-07-12 | エコプロ ビーエム カンパニー リミテッド | リチウム複合酸化物およびこれを含むリチウム二次電池 |
JP7089002B2 (ja) | 2019-11-29 | 2022-06-21 | エコプロ ビーエム カンパニー リミテッド | 正極活物質およびこれを含むリチウム二次電池 |
US11837725B2 (en) | 2019-11-29 | 2023-12-05 | Ecopro Bm Co., Ltd. | Positive electrode active material and lithium secondary battery comprising the same |
JP2021086830A (ja) * | 2019-11-29 | 2021-06-03 | エコプロ ビーエム カンパニー リミテッドEcopro Bm Co., Ltd. | 正極活物質およびこれを含むリチウム二次電池 |
JP2021084856A (ja) * | 2019-11-29 | 2021-06-03 | エコプロ ビーエム カンパニー リミテッドEcopro Bm Co., Ltd. | リチウム複合酸化物およびこれを含むリチウム二次電池 |
JP7482945B2 (ja) | 2019-11-29 | 2024-05-14 | エコプロ ビーエム カンパニー リミテッド | リチウム複合酸化物およびこれを含むリチウム二次電池 |
JP7157219B1 (ja) | 2021-08-03 | 2022-10-19 | 住友化学株式会社 | リチウム二次電池用正極活物質、リチウム二次電池用正極及びリチウム二次電池 |
WO2023013494A1 (ja) * | 2021-08-03 | 2023-02-09 | 住友化学株式会社 | リチウム二次電池用正極活物質、リチウム二次電池用正極及びリチウム二次電池 |
JP2023022605A (ja) * | 2021-08-03 | 2023-02-15 | 住友化学株式会社 | リチウム二次電池用正極活物質、リチウム二次電池用正極及びリチウム二次電池 |
Also Published As
Publication number | Publication date |
---|---|
US20200388841A1 (en) | 2020-12-10 |
JP7176412B2 (ja) | 2022-11-22 |
EP3561924A1 (en) | 2019-10-30 |
CN110392950A (zh) | 2019-10-29 |
US11735726B2 (en) | 2023-08-22 |
EP3561924B1 (en) | 2022-06-29 |
KR20190095302A (ko) | 2019-08-14 |
CN110392950B (zh) | 2023-05-26 |
KR102603503B1 (ko) | 2023-11-20 |
JPWO2018123951A1 (ja) | 2019-10-31 |
EP3561924A4 (en) | 2020-09-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP7176412B2 (ja) | 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 | |
KR102446217B1 (ko) | 비수계 전해질 이차 전지용 정극 활물질과 그의 제조 방법, 및 비수계 전해질 이차 전지 | |
JP6578635B2 (ja) | 非水系電解質二次電池用正極活物質の製造方法、非水系電解質二次電池用正極活物質及びこれを用いた非水系電解質二次電池 | |
US11594726B2 (en) | Positive electrode active material for lithium ion secondary battery, method for manufacturing positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery | |
JP5776996B2 (ja) | 非水系二次電池用正極活物質及びその正極活物質を用いた非水系電解質二次電池 | |
JP2008117729A (ja) | 非水系電解質二次電池用正極活物質、その製造方法及びそれを用いた非水系電解質二次電池 | |
JP7238880B2 (ja) | 金属複合水酸化物とその製造方法、非水電解質二次電池用正極活物質とその製造方法、および非水電解質二次電池 | |
US11870071B2 (en) | Positive electrode active material for non-aqueous electrolyte secondary battery and method for producing the same, method for evaluating positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery | |
JP7272134B2 (ja) | リチウムイオン二次電池用正極活物質およびその製造方法、並びに、リチウムイオン二次電池 | |
US20230187625A1 (en) | Method for producing positive electrode active material for lithium ion secondary battery | |
WO2019087503A1 (ja) | 非水系電解質二次電池用正極活物質、非水系電解質二次電池及び非水系電解質二次電池用正極活物質の製造方法 | |
WO2020027158A1 (ja) | リチウムイオン二次電池用正極活物質、リチウムイオン二次電池用正極活物質の製造方法、リチウムイオン二次電池 | |
JP7183815B2 (ja) | ニッケルマンガンコバルト含有複合水酸化物およびその製造方法、リチウムイオン二次電池用正極活物質およびその製造方法、並びに、リチウムイオン二次電池 | |
US20230378455A1 (en) | Positive electrode active material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery | |
US20220278322A1 (en) | Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery | |
US20220177326A1 (en) | Positive electrode active material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery | |
US20240021808A1 (en) | Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery | |
US20220177325A1 (en) | Positive electrode active material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery | |
JP7197825B2 (ja) | 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17887069 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20197017902 Country of ref document: KR Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 2018559446 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2017887069 Country of ref document: EP Effective date: 20190726 |