WO2016195036A1 - 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 - Google Patents
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 Download PDFInfo
- Publication number
- WO2016195036A1 WO2016195036A1 PCT/JP2016/066467 JP2016066467W WO2016195036A1 WO 2016195036 A1 WO2016195036 A1 WO 2016195036A1 JP 2016066467 W JP2016066467 W JP 2016066467W WO 2016195036 A1 WO2016195036 A1 WO 2016195036A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- positive electrode
- active material
- electrode active
- lithium
- particle diameter
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- 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
-
- 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
- C01G53/66—Nickelates containing alkaline earth metals, e.g. SrNiO3, SrNiO2
-
- 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
- H01M4/36—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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/20—Two-dimensional structures
-
- 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
-
- 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
- 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
- C01P2004/50—Agglomerated particles
-
- 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
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/11—Powder tap density
-
- 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
- C01P2006/12—Surface area
-
- 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
- C01P2006/14—Pore volume
-
- 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
- C01P2006/16—Pore diameter
- C01P2006/17—Pore diameter distribution
-
- 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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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
-
- 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 lithium secondary battery, a positive electrode for a lithium secondary battery, and a lithium secondary battery.
- Lithium metal composite oxide is used as a positive electrode active material for lithium secondary batteries.
- Lithium secondary batteries have already been put into practical use as small power sources for mobile phones and notebook computers, and have been tried to be applied to medium and large power sources for automobiles and power storage.
- Patent Document 1 discloses a lithium secondary battery using a lithium nickel cobalt manganese based composite oxide whose composition formula is represented by Li a Ni 1/3 Co 1/3 Mn 1/3 O 2.
- a positive electrode active material for a lithium secondary battery which is a positive electrode active material for a secondary battery and has a pore diameter in the range of 10 to 200 nm, is disclosed.
- the positive electrode for a lithium secondary battery obtained by using a conventional lithium-containing metal composite compound as a positive electrode active material when pressurized to increase the electrode density of the positive electrode, the particles of the positive electrode active material are easily crushed. There was room for improvement.
- the present invention has been made in view of such circumstances, and an object of the present invention is to provide a positive electrode active material for a lithium secondary battery that can prevent collapsing of particles of the positive electrode active material when the positive electrode active material is pressurized. And Another object of the present invention is to provide a positive electrode for a lithium secondary battery and a lithium secondary battery using such a positive electrode active material for a lithium secondary battery.
- a first aspect of the present invention is a positive electrode active material for a lithium secondary battery that includes at least nickel, cobalt, and manganese and has a layered structure, and satisfies the following requirements (1), (2), and (3): Is a positive electrode active material for a lithium secondary battery.
- the secondary particle diameter is preferably 2.5 ⁇ m or more and 7 ⁇ m or less.
- the BET specific surface area is preferably 1.5 m 2 / g or more and 2.5 m 2 / g or less.
- a pore volume of 200nm or less in the range of 10nm is not more than 0.025 cm 3 / g or more 0.045 cm 3 / g Is preferred.
- a second aspect of the present invention is a positive electrode for a lithium secondary battery having the positive electrode active material for a lithium secondary battery according to the first aspect of the present invention.
- the third aspect of the present invention is a lithium secondary battery having the positive electrode for a lithium secondary battery according to the second aspect of the present invention.
- the present invention it is possible to provide a positive electrode active material for a lithium secondary battery that can prevent the particles of the positive electrode active material from being crushed when the positive electrode active material is pressurized. Moreover, the positive electrode for lithium secondary batteries and lithium secondary battery using such a positive electrode active material for lithium secondary batteries can be provided.
- FIG. 1 is a schematic configuration diagram illustrating an example of a lithium ion secondary battery.
- the positive electrode active material for a lithium secondary battery according to the first aspect of the present invention is a positive electrode active material for a lithium secondary battery that includes at least nickel, cobalt, and manganese and has a layered structure.
- composition formula In the composition formula, ⁇ is preferably 0.30 ⁇ ⁇ 0.33, and more preferably 0.30 ⁇ ⁇ 0.32. In the composition formula, ⁇ is preferably 0.33 ⁇ ⁇ 0.40, and more preferably 0.33 ⁇ ⁇ 0.38.
- the crystal structure of the lithium metal composite oxide used for the positive electrode active material for a lithium secondary battery according to the first aspect of the present invention is a layered structure.
- the layered structure is more preferably a hexagonal crystal structure or a monoclinic crystal structure.
- the hexagonal crystal structures are P3, P3 1 , P3 2 , R3, P-3, R-3, P312, P321, P3 1 12, P3 1 21, P3 2 12, P3 2 21, R32, P3m1, P31m, P3c1, P31c, R3m, R3c, P-31m, P-31c, P-3m1, P-3c1, R-3m, R-3c, P6, P6 1 , P6 5 , P6 2 , P6 4 , P6 3 , P-6, P6 / m, P6 3 / m, P622, P6 1 22, P6 5 22, P6 2 22, P6 4 22, P6 3 22, P6 mm, P6 cc, P6 3 cm, P6 3 mc, P- It belongs to any one space group selected from the group consisting of 6m2, P-6c2, P-62m, P-62c, P6 / mmm, P6 / mcc, P6 3 / mcm, P-
- the monoclinic crystal structure is P2, P2 1 , C2, Pm, Pc, Cm, Cc, P2 / m, P2 1 / m, C2 / m, P2 / c, P2 1 / c, C2 / It belongs to any one space group selected from the group consisting of c.
- the crystal structure of the lithium metal composite oxide is a hexagonal crystal structure belonging to the space group R-3m, or belonging to C2 / m.
- the monoclinic crystal structure is particularly preferable.
- the space group of the lithium metal composite oxide in the present embodiment can be confirmed as follows.
- Rietveld analysis is a technique for analyzing the crystal structure of a material using diffraction peak data (diffraction peak intensity, diffraction angle 2 ⁇ ) in powder X-ray diffraction measurement of the material, and is a conventionally used technique.
- the particle form of the positive electrode active material for a lithium secondary battery of the present invention includes a secondary particle formed by agglomeration of primary particles, and is a mixture of primary particles and secondary particles formed by aggregation of primary particles. There may be.
- the primary particle diameter of the positive electrode active material for a lithium secondary battery is preferably 0.1 ⁇ m or more and 1 ⁇ m or less. The average particle diameter of the primary particles can be measured by observing with an SEM.
- Requirement (2) Secondary particle diameter of positive electrode active material
- the secondary particle diameter formed by aggregation of primary particles is 2 ⁇ m or more and 10 ⁇ m or less.
- the lower limit value of the secondary particle diameter is more preferably 2.5 ⁇ m, and further preferably 3 ⁇ m.
- the upper limit of the secondary particle diameter is more preferably 8 ⁇ m, further preferably 7 ⁇ m, and particularly preferably 6 ⁇ m.
- the upper limit value and the lower limit value of the secondary particle diameter can be arbitrarily combined.
- the combination of the upper limit value and the lower limit value of the secondary particle diameter is preferably 2.5 ⁇ m or more and 7 ⁇ m or less, and more preferably 3.5 ⁇ m or more and 5.0 ⁇ m or less.
- the “secondary particle diameter” of the positive electrode active material for a lithium secondary battery refers to a value measured by the following method (laser diffraction scattering method).
- 0.1 g of a powder of a positive electrode active material for a lithium secondary battery is added to 50 ml of a 0.2 mass% sodium hexametaphosphate aqueous solution to obtain a dispersion in which the powder is dispersed.
- a particle size distribution is measured using the master sizer 2000 (laser diffraction scattering particle size distribution measuring apparatus) by Malvern, and a volume-based cumulative particle size distribution curve is obtained.
- the value of the particle diameter (D 50 ) viewed from the fine particle side at the time of 50% accumulation was taken as the secondary particle diameter of the positive electrode active material for a lithium secondary battery.
- the positive electrode active material for a lithium secondary battery according to the first aspect of the present invention has a pore size of 90 nm or more and 150 nm or less in the pore distribution obtained by the mercury porosimetry. It has a maximum value of pore peak in the range.
- the pore diameter is less than or equal to the above upper limit, a high filling rate can be obtained when the electrode is used. For this reason, crushing of the positive electrode active material particles can be prevented.
- the pore diameter is not less than the above lower limit value, the contact resistance between the positive electrode active material and the electrolytic solution is not lowered, battery resistance is reduced, and high output characteristics can be maintained.
- the upper limit value of the pore diameter showing the maximum value of the pore peak is more preferably 145 nm, and further preferably 140 nm.
- the lower limit of the pore diameter is more preferably 95 nm, and still more preferably 100 nm.
- the upper limit value and the lower limit value of the pore diameter can be arbitrarily combined.
- the pore volume in the range of the pore diameter of 10 nm to 200 nm is 0.025 cm 3 / g or more. It is preferable that it is 0.045 cm ⁇ 3 > / g or less.
- the upper limit of the pore volume in the range is more preferably 0.0425cm 3 / g, further preferably 0.040 cm 3 / g.
- the lower limit of the pore volume in the range is preferably at 0.0275cm 3 / g or more, more preferably 0.030 cm 3 / g or more.
- the upper limit value and the lower limit value of the pore volume in the range can be arbitrarily combined.
- the pore diameter of the positive electrode active material can be obtained by the following method.
- the container is filled with mercury.
- Mercury has a high surface tension, and as it is, mercury does not enter the pores on the surface of the sample.
- the pores increase in size from the smallest to the smallest. Then, mercury gradually enters the pores. If the amount of mercury intrusion is detected while continuously increasing the pressure, a mercury intrusion curve can be obtained from the relationship between the pressure applied to mercury and the amount of mercury intrusion.
- the size of the pore radius of the sample and the volume thereof are calculated based on the obtained mercury intrusion curve.
- a pore distribution curve representing the relationship can be obtained.
- the lower limit is about 2 nm or more
- the upper limit is about 200 ⁇ m or less.
- Measurement by the mercury intrusion method can be performed using an apparatus such as a mercury porosimeter. Specific examples of the mercury porosimeter include Autopore III9420 (manufactured by Micromeritics).
- BET specific surface area of the positive electrode active material of the present embodiment is preferably not more than 1.5 m 2 / g or more 2.5 m 2 / g. When the BET specific surface area is within the above range, the positive electrode active material particles are further prevented from being crushed when the positive electrode active material is pressurized.
- the BET specific surface area of the lithium metal composite oxide is preferably 1.6 m 2 / g or more, preferably 1.7 m 2 / g or more, and more preferably 1.8 m 2 / g or more. .
- the BET specific surface area that is preferable from the viewpoint of filling property is preferably 2.45 m 2 / g or less, preferably 2.4 m 2 / g or less, and preferably 2.3 m 2 / g or less.
- the upper limit value and the lower limit value of the BET specific surface area can be arbitrarily combined.
- the BET specific surface area of the lithium metal composite oxide is in the above range, it can further contribute to prevention of collapsing of the positive electrode active material particles when the positive electrode active material is pressurized.
- the upper limit of the crystallite size at peak A is preferably 1100 ⁇ , more preferably 1000 ⁇ , and still more preferably 950 ⁇ .
- the lower limit of the crystallite size at peak A is preferably 400 ⁇ , more preferably 500 ⁇ , and still more preferably 600 ⁇ .
- the upper limit of the crystallite size at peak B is preferably 750 mm, more preferably 700 mm, and even more preferably 650 mm.
- the lower limit of the crystallite size at peak B is preferably 300 ⁇ , more preferably 400 ⁇ , and even more preferably 500 ⁇ .
- the upper limit value and the lower limit value of the crystallite size in each of peak A and peak B can be arbitrarily combined.
- the crystallite size in the preferable peak A and the crystallite size in the peak B can be arbitrarily combined. Thereby, the cycle characteristic of the obtained lithium secondary battery can be made favorable.
- the crystallite size at peak A and the crystallite size at peak B of the positive electrode active material can be confirmed as follows.
- the positive electrode active material of this embodiment contains the particle
- the void refers to a space having a diameter of 50 nm or more present inside the positive electrode active material particle when the cross section of the positive electrode active material particle is observed. Two or more voids are preferably present in one particle, more preferably five or more, and even more preferably ten or more. By having the voids, the discharge capacity at a high current rate of the obtained lithium secondary battery can be increased.
- the diameter of the voids is preferably in the range of 60 nm to 1000 nm, more preferably in the range of 70 nm to 800 nm, and still more preferably in the range of 75 nm to 600 nm.
- the diameter of the void is in the above range, the density of the electrode using the positive electrode active material particles is increased, and a high capacity lithium secondary battery is obtained.
- measurement method for the void include the following measurement methods.
- the positive electrode active material particles to be measured are dispersed in an epoxy resin and solidified, and the epoxy resin is cross-sectioned by Ar ion milling using Itan made by Gatan, and the processed sample is used with Hitachi High-Technologies S-4800 Then, SEM observation is performed by irradiating an electron beam with an acceleration voltage of 2 kV. Particles are arbitrarily extracted from the image (SEM photograph) obtained by SEM observation, and the distance between the parallel lines sandwiched by parallel lines obtained by subtracting the projected image of the space from a certain direction (constant diameter) ) Is measured as the diameter of the space, and if the diameter is 50 nm or more, a void is formed.
- the positive electrode active material of this embodiment preferably contains 20% or more of particles having voids in the secondary particles, more preferably 50% or more, and even more preferably 80% or more.
- gap inside a secondary particle is defined as including 20% or more of cases where 20 or more particles which have a space
- the tap bulk density of the positive electrode active material for a lithium secondary battery is preferably 1.20 g / mL or more, and preferably 1.25 g / mL or more in the sense of obtaining a lithium secondary battery having a high electrode density. It is more preferable that it is 1.30 g / mL or more. Moreover, it is preferably 1.80 g / mL or less, more preferably 1.65 g / mL or less, and 1.50 g / mL or less in terms of obtaining an electrode having high electrolyte impregnation properties. Further preferred.
- the tap bulk density can be measured based on JIS R 1628-1997. In the present specification, the “heavy load density” corresponds to the tap bulk density in JIS R 1628-1997.
- the ratio of Vs to Vc is preferably 4.0% or less, and 3.5% or less. More preferably, it is 3.3% or less. Further, in the sense of obtaining a positive electrode active material for a lithium secondary battery that has high impregnation with an electrolytic solution, it is preferably 1.0% or more, more preferably 1.5% or more, and 1.7% or more. More preferably.
- the positive electrode active material having the above-described configuration uses the above-described lithium metal composite oxide, the positive electrode active material particles can be prevented from being crushed. For this reason, since the adhesion of the positive electrode active material powder generated at the time of pressurization can be prevented, the operability is good. In addition, the positive electrode active material having the above-described configuration can have a battery resistance superior to that of the conventional one.
- Metals other than lithium that is, at least one essential metal composed of the group consisting of Ni, Co, and Mn, and Fe, Cu, Ti, Mg It is preferable to prepare a metal composite compound containing any one or more of any metal selected from Al, W, Zn, Sn, Zr, Ga, and V, and to fire the metal composite compound with an appropriate lithium salt.
- a metal complex compound a metal complex hydroxide or a metal complex oxide is preferable.
- the metal composite compound can be produced by a generally known production method.
- the manufacturing method will be described in detail by taking a metal composite hydroxide containing nickel, cobalt, and manganese as an example.
- a nickel salt solution, a cobalt salt solution, a manganese salt solution, and a complexing agent are reacted by a coprecipitation method, in particular, a continuous method described in JP-A-2002-201028, and Ni x Co y Mn z (OH) 2
- a composite metal hydroxide represented by the formula (where x + y + z 1) is produced.
- nickel salt which is the solute of the said nickel salt solution For example, any one of nickel sulfate, nickel nitrate, nickel chloride, and nickel acetate can be used.
- cobalt salt that is a solute of the cobalt salt solution for example, any one of cobalt sulfate, cobalt nitrate, and cobalt chloride can be used.
- manganese salt that is a solute of the manganese salt solution for example, any one of manganese sulfate, manganese nitrate, and manganese chloride can be used.
- the above metal salt is used in a proportion corresponding to the composition ratio of Ni x Co y Mn z (OH) 2 .
- water is used as a solvent.
- the complexing agent is capable of forming a complex with nickel, cobalt, and manganese ions in an aqueous solution.
- an ammonium ion supplier (ammonium sulfate, ammonium chloride, ammonium carbonate, ammonium fluoride, etc.), hydrazine, Examples include ethylenediaminetetraacetic acid, nitrilotriacetic acid, uracil diacetic acid, and glycine.
- an alkali metal hydroxide for example, sodium hydroxide or potassium hydroxide
- an alkali metal hydroxide for example, sodium hydroxide or potassium hydroxide
- the complexing agent When the complexing agent is continuously supplied to the reaction vessel in addition to the nickel salt solution, the cobalt salt solution, and the manganese salt solution, nickel, cobalt, and manganese react to form Ni x Co y Mn z (OH) 2. Is manufactured.
- the temperature of the reaction vessel is controlled within a range of, for example, 10 ° C. or more and 60 ° C. or less, preferably 20 to 60 ° C.
- the substance in the reaction vessel is appropriately stirred.
- the reaction vessel is of a type that causes the formed reaction precipitate to overflow for separation.
- the obtained reaction precipitate is washed with water and then dried to isolate nickel cobalt manganese hydroxide as a nickel cobalt manganese composite compound. Moreover, you may wash
- nickel cobalt manganese composite hydroxide is manufactured, but nickel cobalt manganese composite oxide may be prepared.
- the concentration of metal salt to be supplied to the reaction tank By appropriately controlling the concentration of metal salt to be supplied to the reaction tank, the stirring speed, the reaction temperature, the reaction pH, and the firing conditions described later, the primary particle diameter of the lithium metal composite oxide finally obtained in the following steps, Various physical properties such as secondary particle diameter, crystallite size, and BET specific surface area can be controlled.
- bubbling with various gases for example, inert gases such as nitrogen, argon, carbon dioxide, air, oxygen, etc. is used in combination to achieve the desired pore distribution and voids. You may do it. Since the reaction conditions depend on the size of the reaction tank used, the reaction conditions may be optimized while monitoring various physical properties of the finally obtained lithium composite oxide.
- the metal composite oxide or hydroxide is dried and then mixed with a lithium salt.
- the drying conditions are not particularly limited.
- the metal composite oxide or hydroxide is not oxidized / reduced (oxide ⁇ oxide, hydroxide ⁇ hydroxide), and the metal composite hydroxide is oxidized. Any of the conditions (hydroxide ⁇ oxide) and the conditions under which the metal composite oxide is reduced (oxide ⁇ hydroxide) may be used.
- An inert gas such as nitrogen, helium, or an inert gas such as argon may be used for conditions where oxidation / reduction is not performed.
- oxygen or air may be used in an atmosphere. good.
- a reducing agent such as hydrazine or sodium sulfite may be used in an inert gas atmosphere.
- the lithium salt any one of lithium carbonate, lithium nitrate, lithium acetate, lithium hydroxide, lithium hydroxide hydrate, lithium oxide, or a mixture of two or more can be used. Classification may be appropriately performed after the metal composite oxide or hydroxide is dried. The above lithium salt and metal composite hydroxide are used in consideration of the composition ratio of the final object.
- a lithium-nickel cobalt manganese composite oxide is obtained by firing a mixture of a nickel cobalt manganese composite metal hydroxide and a lithium salt. For the firing, dry air, an oxygen atmosphere, an inert atmosphere, or the like is used according to a desired composition, and a plurality of heating steps are performed if necessary.
- the firing temperature of the metal composite oxide or hydroxide and a lithium compound such as lithium hydroxide or lithium carbonate is not particularly limited, but is preferably 850 ° C. or higher and 1100 ° C. or lower, more preferably 850 ° C. or higher and 1050 ° C. C. or lower, particularly preferably 850 ° C. to 1025 ° C.
- 850 ° C. the problem that the energy density (discharge capacity) and the high rate discharge performance are deteriorated easily occurs. In a region below this, there may be a structural factor that hinders the movement of Li.
- a battery having a particularly high energy density (discharge capacity) and excellent charge / discharge cycle performance can be produced.
- the firing time is preferably 3 hours to 50 hours. When the firing time exceeds 50 hours, there is no problem in battery production, but the battery performance tends to be substantially inferior due to the volatilization of Li. If the firing time is less than 3 hours, the crystal growth is poor and the battery performance tends to be poor. In addition, it is also effective to perform temporary baking before the above baking.
- the temperature for such preliminary firing is preferably in the range of 300 to 850 ° C. for 1 to 10 hours.
- the lithium metal composite oxide obtained by firing is appropriately classified after pulverization, and is used as a positive electrode active material applicable to a lithium secondary battery.
- An example of the lithium secondary battery of the present embodiment includes a positive electrode and a negative electrode, a separator sandwiched between the positive electrode and the negative electrode, and an electrolyte solution disposed between the positive electrode and the negative electrode.
- FIG. 1 is a schematic diagram showing an example of the lithium secondary battery of the present embodiment.
- the cylindrical lithium secondary battery 10 of this embodiment is manufactured as follows.
- a pair of separators 1 having a strip shape, a strip-like positive electrode 2 having a positive electrode lead 21 at one end, and a strip-like negative electrode 3 having a negative electrode lead 31 at one end, 2, separator 1, and negative electrode 3 are laminated in this order and wound to form electrode group 4.
- the lithium secondary battery 10 can be manufactured by sealing the upper part of the battery can 5 with the top insulator 7 and the sealing body 8.
- a columnar shape in which the cross-sectional shape when the electrode group 4 is cut in a direction perpendicular to the winding axis is a circle, an ellipse, a rectangle, or a rectangle with rounded corners. Can be mentioned.
- a shape of the lithium secondary battery having such an electrode group 4 a shape defined by IEC 60086 or JIS C 8500 which is a standard for a battery defined by the International Electrotechnical Commission (IEC) can be adopted. .
- IEC 60086 or JIS C 8500 which is a standard for a battery defined by the International Electrotechnical Commission (IEC)
- cylindrical shape, square shape, etc. can be mentioned.
- the lithium secondary battery is not limited to the above-described wound type configuration, and may have a stacked type configuration in which a stacked structure of a positive electrode, a separator, a negative electrode and a separator is repeatedly stacked.
- Examples of the stacked lithium secondary battery include so-called coin-type batteries, button-type batteries, and paper-type (or sheet-type) batteries.
- the positive electrode of the present embodiment can be produced by first adjusting a positive electrode mixture containing a positive electrode active material, a conductive material and a binder, and supporting the positive electrode mixture on a positive electrode current collector.
- a carbon material As the conductive material included in the positive electrode of the present embodiment, a carbon material can be used.
- the carbon material include graphite powder, carbon black (for example, acetylene black), and a fibrous carbon material. Since carbon black is fine and has a large surface area, adding a small amount to the positive electrode mixture can improve the conductivity inside the positive electrode and improve the charge / discharge efficiency and output characteristics. Both the binding force between the positive electrode mixture and the positive electrode current collector and the binding force inside the positive electrode mixture are reduced, which causes an increase in internal resistance.
- the proportion of the conductive material in the positive electrode mixture is preferably 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the positive electrode active material.
- a fibrous carbon material such as graphitized carbon fiber or carbon nanotube is used as the conductive material, this ratio can be lowered.
- thermoplastic resin As the binder included in the positive electrode of the present embodiment, a thermoplastic resin can be used.
- the thermoplastic resin include polyvinylidene fluoride (hereinafter sometimes referred to as PVdF), polytetrafluoroethylene (hereinafter sometimes referred to as PTFE), tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride.
- fluororesins such as copolymers, propylene hexafluoride / vinylidene fluoride copolymers, tetrafluoroethylene / perfluorovinyl ether copolymers; polyolefin resins such as polyethylene and polypropylene.
- thermoplastic resins may be used as a mixture of two or more.
- a fluororesin and a polyolefin resin as a binder, the ratio of the fluororesin to the whole positive electrode mixture is 1% by mass or more and 10% by mass or less, and the ratio of the polyolefin resin is 0.1% by mass or more and 2% by mass or less.
- a positive electrode mixture having both high adhesion to the current collector and high bonding strength inside the positive electrode mixture can be obtained.
- a band-shaped member made of a metal material such as Al, Ni, and stainless steel can be used as the positive electrode current collector included in the positive electrode of the present embodiment.
- a material that is made of Al and formed into a thin film is preferable because it is easy to process and inexpensive.
- Examples of the method of supporting the positive electrode mixture on the positive electrode current collector include a method of pressure-molding the positive electrode mixture on the positive electrode current collector.
- the positive electrode active material since the above-described lithium-containing composite metal oxide is used as the positive electrode active material for a lithium secondary battery, the positive electrode active material is prevented from being crushed when this pressure molding is performed. For this reason, adhesion of the positive electrode active material powder generated by pulverizing the positive electrode active material on a component such as a roll for pressurization can be prevented.
- the positive electrode mixture is made into a paste using an organic solvent, and the resulting positive electrode mixture paste is applied to at least one surface side of the positive electrode current collector, dried, pressed and fixed, whereby the positive electrode current collector is bonded to the positive electrode current collector.
- a mixture may be supported.
- usable organic solvents include amine solvents such as N, N-dimethylaminopropylamine and diethylenetriamine; ether solvents such as tetrahydrofuran; ketone solvents such as methyl ethyl ketone; methyl acetate And amide solvents such as dimethylacetamide and N-methyl-2-pyrrolidone (hereinafter sometimes referred to as NMP).
- Examples of the method of applying the positive electrode mixture paste to the positive electrode current collector include a slit die coating method, a screen coating method, a curtain coating method, a knife coating method, a gravure coating method, and an electrostatic spray method.
- a positive electrode can be manufactured by the method mentioned above.
- the negative electrode included in the lithium secondary battery of this embodiment is only required to be able to dope and dedope lithium ions at a lower potential than the positive electrode, and the negative electrode mixture containing the negative electrode active material is supported on the negative electrode current collector. And an electrode made of a negative electrode active material alone.
- Negative electrode active material examples of the negative electrode active material possessed by the negative electrode include carbon materials, chalcogen compounds (oxides, sulfides, etc.), nitrides, metals, and alloys that can be doped and dedoped with lithium ions at a lower potential than the positive electrode. It is done.
- Examples of carbon materials that can be used as the negative electrode active material include graphites such as natural graphite and artificial graphite, cokes, carbon black, pyrolytic carbons, carbon fibers, and organic polymer compound fired bodies.
- the oxide can be used as an anode active material, (wherein, x represents a positive real number) SiO 2, SiO, etc. formula SiO x oxides of silicon represented by; TiO 2, TiO, etc. formula TiO x (wherein , X is a positive real number); oxide of titanium represented by formula VO x (where x is a positive real number) such as V 2 O 5 and VO 2 ; Fe 3 O 4 , Fe 2 O 3 , FeO, etc. Iron oxide represented by the formula FeO x (where x is a positive real number); SnO 2 , SnO, etc.
- Examples of sulfides that can be used as the negative electrode active material include titanium sulfides represented by the formula TiS x (where x is a positive real number) such as Ti 2 S 3 , TiS 2 , and TiS; V 3 S 4 , VS 2, VS and other vanadium sulfides represented by the formula VS x (where x is a positive real number); Fe 3 S 4 , FeS 2 , FeS and other formulas FeS x (where x is a positive real number) Iron sulfide represented; Mo 2 S 3 , MoS 2 and the like MoS x (where x is a positive real number) Molybdenum sulfide; SnS 2, SnS and other formula SnS x (where, a sulfide of tin represented by x is a positive real number; a sulfide of tungsten represented by a formula WS x (where x is a positive real number) such as WS 2
- Examples of the nitride that can be used as the negative electrode active material include Li 3 N and Li 3-x A x N (where A is one or both of Ni and Co, and 0 ⁇ x ⁇ 3). And lithium-containing nitrides.
- These carbon materials, oxides, sulfides and nitrides may be used alone or in combination of two or more. These carbon materials, oxides, sulfides and nitrides may be crystalline or amorphous.
- examples of the metal that can be used as the negative electrode active material include lithium metal, silicon metal, and tin metal.
- Alloys that can be used as the negative electrode active material include lithium alloys such as Li—Al, Li—Ni, Li—Si, Li—Sn, and Li—Sn—Ni; silicon alloys such as Si—Zn; Sn—Mn, Sn -Tin alloys such as Co, Sn-Ni, Sn-Cu, Sn-La; alloys such as Cu 2 Sb, La 3 Ni 2 Sn 7 ;
- These metals and alloys are mainly used alone as electrodes after being processed into a foil shape, for example.
- the potential of the negative electrode hardly changes from the uncharged state to the fully charged state during charging (potential flatness is good), the average discharge potential is low, and the capacity retention rate when repeatedly charged and discharged is high.
- a carbon material mainly composed of graphite such as natural graphite or artificial graphite is preferably used.
- the shape of the carbon material may be any of a flake shape such as natural graphite, a spherical shape such as mesocarbon microbeads, a fibrous shape such as graphitized carbon fiber, or an aggregate of fine powder.
- the negative electrode mixture may contain a binder as necessary.
- the binder include thermoplastic resins, and specific examples include PVdF, thermoplastic polyimide, carboxymethyl cellulose, polyethylene, and polypropylene.
- the negative electrode current collector of the negative electrode examples include a band-shaped member made of a metal material such as Cu, Ni, and stainless steel. In particular, it is preferable to use Cu as a forming material and process it into a thin film from the viewpoint that it is difficult to make an alloy with lithium and it is easy to process.
- Examples of the separator included in the lithium secondary battery of the present embodiment include a porous film, a nonwoven fabric, a woven fabric, and the like made of a material such as a polyolefin resin such as polyethylene and polypropylene, a fluororesin, and a nitrogen-containing aromatic polymer. The material which has can be used. Moreover, a separator may be formed by using two or more of these materials, or a separator may be formed by laminating these materials.
- separator examples include separators described in JP 2000-30686 A, JP 10-324758 A, and the like.
- the thickness of the separator should be as thin as possible so that the mechanical strength can be maintained in that the volume energy density of the battery is increased and the internal resistance is reduced, preferably about 5 to 200 ⁇ m, more preferably about 5 to 40 ⁇ m. is there.
- the separator preferably has a porous film containing a thermoplastic resin.
- Lithium secondary batteries have a function that shuts down the current when the abnormal current flows in the battery due to a short circuit between the positive electrode and the negative electrode, blocking the current at the short circuit point and shutting off the excessive current. It is preferable to have.
- the shutdown is performed by overheating the separator at the short-circuit location due to a short circuit, and when the temperature exceeds a presumed operating temperature, the porous film in the separator is softened or melted to close the micropores. And even if the temperature in a battery rises to a certain high temperature after a separator shuts down, it is preferable to maintain the shut-down state, without breaking at the temperature.
- Examples of such a separator include a laminated film in which a heat-resistant porous layer and a porous film are laminated.
- a laminated film By using such a laminated film as a separator, the heat resistance of the secondary battery in this embodiment can be further increased.
- the heat resistant porous layer may be laminated on both surfaces of the porous film.
- the heat resistant porous layer is a layer having higher heat resistance than the porous film.
- the heat resistant porous layer may be formed from an inorganic powder (first heat resistant porous layer), may be formed from a heat resistant resin (second heat resistant porous layer), and includes a heat resistant resin and a filler. (A third heat-resistant porous layer).
- first heat resistant porous layer may be formed from a heat resistant resin
- second heat resistant porous layer may be formed from a heat resistant resin
- a third heat-resistant porous layer A third heat-resistant porous layer.
- the heat resistant porous layer contains a heat resistant resin
- the heat resistant porous layer can be formed by an easy technique such as coating.
- the heat resistant porous layer is formed of an inorganic powder
- examples of the inorganic powder used for the heat resistant porous layer include inorganic substances such as metal oxides, metal nitrides, metal carbides, metal hydroxides, carbonates, and sulfates.
- a powder made of an inorganic substance having low conductivity (insulator) is preferably used.
- Specific examples include powders made of alumina, silica, titanium dioxide, calcium carbonate, or the like. Such inorganic powders may be used alone or in combination of two or more.
- alumina powder is preferable because of its high chemical stability. More preferably, all of the particles constituting the inorganic powder are alumina particles, all of the particles constituting the inorganic powder are alumina particles, and part or all of them are substantially spherical alumina particles. preferable.
- the heat-resistant resin used for the heat-resistant porous layer includes polyamide, polyimide, polyamideimide, polycarbonate, polyacetal, polysulfone, polyphenylene sulfide, polyether ketone, aromatic polyester, polyether Mention may be made of sulfone and polyetherimide.
- polyamide, polyimide, polyamideimide, polyethersulfone and polyetherimide are preferable, and polyamide, polyimide or polyamideimide is more preferable.
- the heat-resistant resin used for the heat-resistant porous layer is a nitrogen-containing aromatic polymer such as aromatic polyamide (para-oriented aromatic polyamide, meta-oriented aromatic polyamide), aromatic polyimide, aromatic polyamideimide, Aromatic polyamides are preferred, and para-oriented aromatic polyamides (hereinafter sometimes referred to as para-aramids) are particularly preferred because they are easy to produce.
- aromatic polyamide para-oriented aromatic polyamide, meta-oriented aromatic polyamide
- aromatic polyimide aromatic polyimide
- aromatic polyamideimide aromatic polyamideimide
- Aromatic polyamides are preferred, and para-oriented aromatic polyamides (hereinafter sometimes referred to as para-aramids) are particularly preferred because they are easy to produce.
- examples of the heat-resistant resin include poly-4-methylpentene-1 and cyclic olefin polymers.
- the heat resistance of the laminated film used as the separator of the lithium secondary battery that is, the thermal film breaking temperature of the laminated film can be further increased.
- these heat-resistant resins when using a nitrogen-containing aromatic polymer, because of the polarity in the molecule, compatibility with the electrolyte, that is, the liquid retention in the heat-resistant porous layer may be improved, The rate of impregnation of the electrolytic solution during the production of the lithium secondary battery is high, and the charge / discharge capacity of the lithium secondary battery is further increased.
- the thermal film breaking temperature of such a laminated film depends on the type of heat-resistant resin, and is selected and used according to the use scene and purpose of use. More specifically, as the heat-resistant resin, the cyclic olefin polymer is used at about 400 ° C. when the nitrogen-containing aromatic polymer is used, and at about 250 ° C. when poly-4-methylpentene-1 is used. When using, the thermal film breaking temperature can be controlled to about 300 ° C., respectively. In addition, when the heat resistant porous layer is made of an inorganic powder, the thermal film breaking temperature can be controlled to, for example, 500 ° C. or higher.
- the para-aramid is obtained by condensation polymerization of a para-oriented aromatic diamine and a para-oriented aromatic dicarboxylic acid halide, and the amide bond is in the para position of the aromatic ring or an oriented position equivalent thereto (for example, 4,4 ′ -Substantially consisting of repeating units bonded in the opposite direction, such as biphenylene, 1,5-naphthalene, 2,6-naphthalene, etc., oriented in the opposite direction coaxially or in parallel.
- para-aramid having a structure according to the type.
- the aromatic polyimide is preferably a wholly aromatic polyimide produced by condensation polymerization of an aromatic dianhydride and a diamine.
- aromatic dianhydride used for the condensation polymerization examples include pyromellitic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 ′, 4. , 4'-benzophenonetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride It is done.
- diamine used for the condensation polymerization examples include oxydianiline, paraphenylenediamine, benzophenone diamine, 3,3′-methylenedianiline, 3,3′-diaminobenzophenone, 3,3′-diaminodiphenylsulfone. And 1,5-naphthalenediamine.
- aromatic polyimide a polyimide soluble in a solvent can be suitably used.
- An example of such a polyimide is a polycondensate polyimide of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride and an aromatic diamine.
- aromatic polyamideimide those obtained from condensation polymerization using aromatic dicarboxylic acid and aromatic diisocyanate, those obtained from condensation polymerization using aromatic diacid anhydride and aromatic diisocyanate Is mentioned.
- aromatic dicarboxylic acid include isophthalic acid and terephthalic acid.
- aromatic dianhydride is trimellitic anhydride.
- aromatic diisocyanate include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, orthotolylene diisocyanate, and m-xylene diisocyanate.
- the heat-resistant porous layer of the laminated film preferably has a thickness of 1 to 10 ⁇ m, more preferably 1 to 5 ⁇ m, particularly 1 to 4 ⁇ m. .
- the heat-resistant porous layer has fine pores, and the size (diameter) of the pores is preferably 3 ⁇ m or less, more preferably 1 ⁇ m or less.
- the heat resistant porous layer is formed including a heat resistant resin and a filler
- the same heat resistant resin as that used for the second heat resistant porous layer can be used.
- the filler one or more selected from the group consisting of organic powder, inorganic powder, or a mixture thereof can be used.
- the particles constituting the filler preferably have an average particle size of 0.01 ⁇ m or more and 1 ⁇ m or less.
- organic powder examples include, for example, styrene, vinyl ketone, acrylonitrile, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, methyl acrylate, and the like, or two or more types of copolymers; PTFE, Fluorine resin such as tetrafluoroethylene-6fluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride; melamine resin; urea resin; polyolefin resin; polymethacrylate; A powder is mentioned. Such organic powders may be used alone or in combination of two or more. Among these organic powders, PTFE powder is preferred because of its high chemical stability.
- Examples of the inorganic powder that can be used as the filler include the same inorganic powder used in the heat-resistant porous layer.
- the filler content depends on the specific gravity of the filler material, for example, when all of the particles constituting the filler are alumina particles
- the mass of the filler is preferably 5 parts by mass or more and 95 parts by mass or less, more preferably 20 parts by mass or more and 95 parts by mass or less, Preferably they are 30 to 90 mass parts. These ranges can be appropriately set depending on the specific gravity of the filler material.
- Examples of the shape of the filler include substantially spherical, plate-like, columnar, needle-like, and fiber-like shapes, and any particle can be used. However, since it is easy to form uniform pores, Preferably there is.
- Examples of the substantially spherical particles include particles having a particle aspect ratio (long particle diameter / short particle diameter) of 1 or more and 1.5 or less. The aspect ratio of the particles can be measured by an electron micrograph.
- the porous film preferably has fine holes and has a shutdown function.
- the porous film contains a thermoplastic resin.
- the size of the micropores in the porous film is preferably 3 ⁇ m or less, more preferably 1 ⁇ m or less.
- the porosity of the porous film is preferably 30% to 80% by volume, more preferably 40% to 70% by volume.
- the porous film containing the thermoplastic resin closes the micropores by softening or melting of the thermoplastic resin constituting the porous film. be able to.
- thermoplastic resin used for a porous film what does not melt
- specific examples include polyolefin resins such as polyethylene and polypropylene, and thermoplastic polyurethane resins, and a mixture of two or more of these may be used.
- the porous film preferably contains polyethylene.
- the polyethylene include polyethylene such as low density polyethylene, high density polyethylene, and linear polyethylene, and ultra high molecular weight polyethylene having a molecular weight of 1,000,000 or more.
- the thermoplastic resin constituting the porous film contains at least ultra high molecular weight polyethylene.
- the thermoplastic resin may preferably contain a wax made of polyolefin having a low molecular weight (weight average molecular weight of 10,000 or less).
- the thickness of the porous film in the laminated film is preferably 3 ⁇ m or more and 30 ⁇ m or less, more preferably 3 ⁇ m or more and 25 ⁇ m or less.
- the thickness of a laminated film becomes like this. Preferably it is 40 micrometers or less, More preferably, it is 30 micrometers or less.
- the value of A / B is preferably 0.1 or more and 1 or less.
- the separator allows the electrolyte to permeate well when the battery is used (during charging / discharging). Therefore, the air resistance according to the Gurley method defined in JIS P 8117 is 50 seconds / 100 cc or more, 300 seconds / 100 cc. Or less, more preferably 50 seconds / 100 cc or more and 200 seconds / 100 cc or less.
- the porosity of the separator is preferably 30% by volume to 80% by volume, more preferably 40% by volume to 70% by volume.
- the separator may be a laminate of separators having different porosity.
- the electrolyte solution included in the lithium secondary battery of this embodiment contains an electrolyte and an organic solvent.
- the electrolyte contained in the electrolyte includes LiClO 4 , LiPF 6 , LiAsF 6 , LiSbF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 C 2 F 5 ) 2 , LiN (SO 2 CF 3 ) (COCF 3 ), Li (C 4 F 9 SO 3 ), LiC (SO 2 CF 3 ) 3 , Li 2 B 10 Cl 10 , LiBOB (where BOB is bis (oxalato) borate LiFSI (here, FSI is bis (fluorosulfonyl) imide), lithium salt such as lower aliphatic carboxylic acid lithium salt, LiAlCl 4, and a mixture of two or more of these May be used.
- BOB bis (oxalato) borate LiFSI (here, FSI is bis (fluorosulfonyl) imide)
- lithium salt such as lower aliphatic
- the electrolyte is at least selected from the group consisting of LiPF 6 containing fluorine, LiAsF 6 , LiSbF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (SO 2 CF 3 ) 2 and LiC (SO 2 CF 3 ) 3. It is preferable to use one containing one kind.
- Examples of the organic solvent contained in the electrolyte include propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, 4-trifluoromethyl-1,3-dioxolan-2-one, and 1,2-di- Carbonates such as (methoxycarbonyloxy) ethane; 1,2-dimethoxyethane, 1,3-dimethoxypropane, pentafluoropropyl methyl ether, 2,2,3,3-tetrafluoropropyl difluoromethyl ether, tetrahydrofuran, 2- Ethers such as methyltetrahydrofuran; Esters such as methyl formate, methyl acetate and ⁇ -butyrolactone; Nitriles such as acetonitrile and butyronitrile; N, N-dimethylformamide, N, N-dimethyla Amides such as toamide; carbamates such as 3-methyl-2-oxazolidone;
- a mixed solvent containing carbonates is preferable, and a mixed solvent of cyclic carbonate and acyclic carbonate and a mixed solvent of cyclic carbonate and ether are more preferable.
- a mixed solvent of cyclic carbonate and acyclic carbonate a mixed solvent containing ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is preferable.
- the electrolyte using such a mixed solvent has a wide operating temperature range, hardly deteriorates even when charged and discharged at a high current rate, hardly deteriorates even when used for a long time, and natural graphite as an active material of the negative electrode. Even when a graphite material such as artificial graphite is used, it has many features that it is hardly decomposable.
- an electrolytic solution containing a lithium salt containing fluorine such as LiPF 6 and an organic solvent having a fluorine substituent because the safety of the obtained lithium secondary battery is increased.
- a mixed solvent containing ethers having fluorine substituents such as pentafluoropropyl methyl ether and 2,2,3,3-tetrafluoropropyl difluoromethyl ether and dimethyl carbonate is capable of capacity even when charging / discharging at a high current rate. Since a maintenance rate is high, it is more preferable.
- a solid electrolyte may be used instead of the above electrolytic solution.
- the solid electrolyte for example, an organic polymer electrolyte such as a polyethylene oxide polymer compound, a polymer compound containing at least one of a polyorganosiloxane chain or a polyoxyalkylene chain can be used.
- maintained the nonaqueous electrolyte in the high molecular compound can also be used.
- Li 2 S—SiS 2 , Li 2 S—GeS 2 , Li 2 S—P 2 S 5 , Li 2 S—B 2 S 3 , Li 2 S—SiS 2 —Li 3 PO 4 , Li 2 S—SiS 2 -Li 2 SO 4, Li 2 S-GeS 2 -P 2 S 5 inorganic solid electrolytes containing a sulfide, and the like, may be used a mixture of two or more thereof. By using these solid electrolytes, the safety of the lithium secondary battery may be further improved.
- the solid electrolyte when a solid electrolyte is used, the solid electrolyte may serve as a separator, and in that case, the separator may not be required.
- the positive electrode having the above-described configuration includes the positive electrode active material using the above-described lithium metal composite oxide, it is possible to improve the collapse of the positive electrode active material particles. For this reason, since the adhesion of the positive electrode active material powder generated at the time of pressurization can be prevented, the operability is good.
- the positive electrode having the above-described configuration can have a battery resistance superior to that of the conventional one.
- the lithium secondary battery having the above-described configuration includes the positive electrode described above, it is possible to improve the collapse of the positive electrode active material particles. For this reason, since the adhesion of the positive electrode active material powder generated at the time of pressurization can be prevented, the operability is good. In addition, the battery resistance can be made better than before.
- the evaluation of the lithium metal composite oxide (positive electrode active material) and the production evaluation of the positive electrode and the lithium secondary battery were performed as follows.
- composition analysis of positive electrode active material for lithium secondary battery is conducted by dissolving the obtained lithium metal composite oxide powder in hydrochloric acid and then inductively coupled plasma emission. The analysis was performed using an analyzer (manufactured by SII Nanotechnology Inc., SPS3000).
- the lithium metal composite oxide particles to be measured are placed on a conductive sheet affixed on a sample stage, and JSM-5510 manufactured by JEOL Ltd. is used. SEM observation was performed by irradiating an electron beam with an acceleration voltage of 20 kV. 50 primary particles are arbitrarily extracted from an image (SEM photograph) obtained by SEM observation, and for each primary particle, a distance between parallel lines sandwiched by parallel lines obtained by drawing a projection image of the primary particles from a certain direction. (Constant direction diameter) was measured as the particle diameter of the primary particles. The arithmetic average value of the obtained particle diameter was defined as the average primary particle diameter of the lithium metal composite oxide.
- Measurement conditions Measurement temperature: 25 ° C Measurement pressure: 1.07 psia to 59256.3 psia
- Example 1 Production of positive electrode active material A1 After water was put into a reaction vessel equipped with a stirrer and an overflow pipe, an aqueous sodium hydroxide solution was added.
- a nickel sulfate aqueous solution, a cobalt sulfate aqueous solution, and a manganese sulfate aqueous solution are mixed so that the atomic ratio of nickel atoms, cobalt atoms, and manganese atoms is 0.315: 0.330: 0.355, and a mixed raw material solution is prepared. It was adjusted.
- this mixed raw material solution and aqueous ammonium sulfate solution are continuously added as a complexing agent to the reaction vessel, and the pH of the solution in the reaction vessel is kept at 50 ° C. while maintaining the pH at 12.1.
- a sodium hydroxide aqueous solution was dropped in a timely manner to obtain nickel cobalt manganese composite hydroxide particles.
- the obtained particles were filtered, washed with water, and dried at 100 ° C. to obtain a nickel cobalt manganese composite hydroxide dry powder.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 38.6 m 2 / g.
- the secondary particle diameter of the positive electrode active material A1 was 2.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A1 were 778 mm and 510 mm, respectively.
- the maximum pore peak was at 92 nm, and the pore volume in the range of 10 nm to 200 nm was 0.039 cm 3 / g.
- the BET specific surface area was 2.4 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material was 1.7 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.4 ⁇ m.
- Example 2 Manufacture of positive electrode active material A2 Except having set the pH of the solution in a reaction tank to 11.7, operation similar to Example 1 was performed and the nickel cobalt manganese composite hydroxide was obtained.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 32.5 m 2 / g.
- lithium-nickel cobalt manganese composite oxide A2 was obtained.
- the secondary particle diameter of the positive electrode active material A2 was 4.3 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A2 were 830 mm and 508 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.037 cm 3 / g.
- the BET specific surface area was 2.4 m 2 / g.
- Secondary particle diameter after pressurization of positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 4.0 ⁇ m, and the change in secondary particle diameter ( ⁇ D 50 ) was 0.3 ⁇ m.
- Example 3 Manufacture of positive electrode active material A3 Except having set the pH of the solution in a reaction tank to 11.3, operation similar to Example 1 was performed and nickel cobalt manganese composite hydroxide was obtained.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 29.7 m 2 / g.
- lithium-nickel cobalt manganese composite oxide A3 was obtained.
- the secondary particle diameter of the positive electrode active material A3 was 5.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A3 were 746 mm and 434 mm, respectively.
- the maximum pore peak was at 134 nm, and the pore volume in the range of 10 nm to 200 nm was 0.033 cm 3 / g.
- the BET specific surface area was 2.1 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 4.6 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 4 Manufacture of positive electrode active material A4 Except having set the temperature of the solution in a reaction tank to 40 degreeC and pH to 11.3, operation similar to Example 1 was performed and the nickel cobalt manganese composite hydroxide was obtained.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 22.1 m 2 / g.
- lithium-nickel cobalt manganese composite oxide A4 was obtained.
- the secondary particle diameter of the positive electrode active material A4 was 8.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A4 were 879 mm and 546 mm, respectively.
- the maximum pore peak was at 121 nm, and the pore volume in the range of 10 nm to 200 nm was 0.031 cm 3 / g. Moreover, the BET specific surface area was 1.9 m ⁇ 2 > / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 7.6 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 5 Manufacture of positive electrode active material A5 Except having set the temperature of the solution in a reaction tank to 40 degreeC and pH to 11.1, operation similar to Example 1 was performed and the nickel cobalt manganese composite hydroxide was obtained.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 18.6 m 2 / g.
- lithium-nickel cobalt manganese composite oxide A5 was obtained.
- the secondary particle diameter of the positive electrode active material A5 was 9.8 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A5 were 820 mm and 511 mm, respectively.
- the maximum pore peak was at 112 nm, and the pore volume in the range of 10 nm to 200 nm was 0.030 cm 3 / g.
- the BET specific surface area was 1.6 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 9.2 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 1 Manufacture of positive electrode active material B1 Except having set the temperature of the solution in a reaction tank to 30 degreeC and pH to 12.7, operation similar to Example 1 was performed and nickel cobalt manganese composite hydroxide was obtained.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 46.6 m 2 / g.
- lithium-nickel cobalt manganese composite oxide B1 was obtained.
- the measurement of the secondary particle diameter of the positive electrode active material B1 was 1.5 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B1 were 895 mm and 504 mm, respectively.
- the maximum pore peak was at 53 nm, and the pore volume in the range of 10 nm to 200 nm was 0.042 cm 3 / g.
- the BET specific surface area was 2.9 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 0.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.1 ⁇ m.
- Example 2 Production of positive electrode active material B2 A nickel cobalt manganese composite hydroxide was obtained in the same manner as in Example 1 except that the temperature of the solution in the reaction vessel was set to 30 ° C. and the pH was set to 12.0. The nickel-cobalt-manganese composite hydroxide had a BET specific surface area of 19.2 m 2 / g. In the same manner as in Example 1, lithium-nickel cobalt manganese composite oxide B2 was obtained.
- the secondary particle diameter of the positive electrode active material B2 was 11.5 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B2 were 976 mm and 623 mm, respectively.
- the maximum pore peak was at 76 nm, and the pore volume in the range of 10 nm to 200 nm was 0.013 cm 3 / g.
- the BET specific surface area was 1.3 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 10.2 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.3 ⁇ m.
- Example 3 Production of positive electrode active material B3 A nickel sulfate aqueous solution, a cobalt sulfate aqueous solution and a manganese sulfate aqueous solution were mixed so that the atomic ratio of nickel atom, cobalt atom and manganese atom was 0.334: 0.333: 0.333.
- the mixed raw material liquid was adjusted, and the same operation as in Example 1 was carried out except that the temperature of the solution in the reaction vessel was set to 30 ° C. and the pH was set to 12.4 to obtain a nickel cobalt manganese composite hydroxide. It was.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 21.3 m 2 / g. In the same manner as in Example 1, lithium-nickel cobalt manganese composite oxide B3 was obtained.
- the secondary particle diameter of the positive electrode active material B3 was 3.0 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B3 were 1006 mm and 605 mm, respectively.
- the maximum pore peak was at 86 nm, and the pore volume in the range of 10 nm to 200 nm was 0.020 cm 3 / g.
- the BET specific surface area was 1.6 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.0 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.0 ⁇ m.
- Example 4 Production of Positive Electrode Active Material B4
- a nickel sulfate aqueous solution, a cobalt sulfate aqueous solution, and a manganese sulfate aqueous solution were mixed so that the atomic ratio of nickel atoms, cobalt atoms, and manganese atoms was 0.334: 0.333: 0.333.
- the mixed raw material liquid was adjusted, and the same operation as in Example 1 was performed except that the temperature of the solution in the reaction vessel was set to 30 ° C. and the pH was set to 11.1 to obtain a nickel cobalt manganese composite hydroxide. It was.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 11.6 m 2 / g.
- lithium-nickel cobalt manganese composite oxide B4 was obtained.
- the secondary particle diameter of the positive electrode active material B4 was 8.9 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B4 were 1187 mm and 721 mm, respectively.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 7.8 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.1 ⁇ m.
- Example 5 Production of positive electrode active material B5 A nickel sulfate aqueous solution, a cobalt sulfate aqueous solution and a manganese sulfate aqueous solution were mixed so that the atomic ratio of nickel atom, cobalt atom and manganese atom was 0.334: 0.333: 0.333.
- the mixed raw material liquid was adjusted, and the same operation as in Example 1 was performed except that the temperature of the solution in the reaction vessel was set to 40 ° C. and the pH was set to 11.0, thereby obtaining a nickel cobalt manganese composite hydroxide. It was.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 10.2 m 2 / g.
- lithium-nickel cobalt manganese composite oxide B5 was obtained.
- the secondary particle diameter of the positive electrode active material B5 was 11.8 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B5 were 1201 mm and 743 mm, respectively.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 10.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.3 ⁇ m.
- Example 6 Production of positive electrode active material B6 A nickel sulfate aqueous solution, a cobalt sulfate aqueous solution and a manganese sulfate aqueous solution were mixed so that the atomic ratio of nickel atoms, cobalt atoms and manganese atoms was 0.334: 0.333: 0.333. Then, the mixed raw material liquid was adjusted, and the same operation as in Example 1 was performed except that the pH of the solution in the reaction vessel was set to 11.1, thereby obtaining a nickel cobalt manganese composite hydroxide. The nickel cobalt manganese composite hydroxide had a BET specific surface area of 22.3 m 2 / g. In the same manner as in Example 1, lithium-nickel cobalt manganese composite oxide B6 was obtained.
- the secondary particle diameter of the positive electrode active material B6 was 4.3 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B6 were 1046 mm and 661 mm, respectively.
- the maximum pore peak was at 167 nm, and the pore volume in the range of 10 nm to 200 nm was 0.029 cm 3 / g.
- the BET specific surface area was 1.4 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after performing the pressurization test of the positive electrode active material under the pressure test conditions is 3.2 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.1 ⁇ m.
- Example 7 Production of positive electrode active material B7 A nickel sulfate aqueous solution, a cobalt sulfate aqueous solution, and a manganese sulfate aqueous solution were mixed so that the atomic ratio of nickel atoms, cobalt atoms, and manganese atoms was 0.35: 0.30: 0.35. Then, the mixed raw material liquid was adjusted, and the same operation as in Example 1 was carried out except that the pH of the solution in the reaction vessel was set to 11.4 to obtain a nickel cobalt manganese composite hydroxide. The nickel cobalt manganese composite hydroxide had a BET specific surface area of 20.0 m 2 / g. In the same manner as in Example 1, lithium-nickel cobalt manganese composite oxide B7 was obtained.
- the secondary particle diameter of the positive electrode active material B7 was 4.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material B7 were 920 mm and 526 mm, respectively.
- the maximum pore peak was at 168 nm, and the pore volume in the range from 10 nm to 200 nm was 0.039 cm 3 / g.
- the BET specific surface area was 1.7 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after performing the pressurization test of the positive electrode active material under the pressure test conditions is 3.2 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 1.0 ⁇ m.
- the change in secondary particle diameter before and after pressurization was as small as 0.6 ⁇ m or less, and the positive electrode during pressurization The collapse of the active material was greatly suppressed.
- the positive electrode active materials using the lithium metal composite oxides of Comparative Examples 1 to 7 have a large change in secondary particle diameter ( ⁇ D 50 ) before and after pressing of 1.0 ⁇ m or more. The material has collapsed.
- Example 6 Production of positive electrode active material A6 After water was put into a reaction vessel equipped with a stirrer and an overflow pipe, an aqueous sodium hydroxide solution was added.
- a nickel sulfate aqueous solution, a cobalt sulfate aqueous solution, and a manganese sulfate aqueous solution are mixed so that the atomic ratio of nickel atoms, cobalt atoms, and manganese atoms is 0.315: 0.330: 0.355, and a mixed raw material solution is prepared. It was adjusted.
- this mixed raw material solution and aqueous ammonium sulfate solution are continuously added as a complexing agent to the reaction vessel, and the pH of the solution in the reaction vessel is kept at 50 ° C. while maintaining the pH at 12.3.
- a sodium hydroxide aqueous solution was dropped in a timely manner to obtain nickel cobalt manganese composite hydroxide particles.
- the obtained particles were filtered, washed with water, and dried at 100 ° C. to obtain a nickel cobalt manganese composite hydroxide dry powder.
- the nickel cobalt manganese composite hydroxide had a BET specific surface area of 34.7 m 2 / g.
- the secondary particle diameter of the positive electrode active material A6 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A6 were 905 mm and 533 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.032 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 7 Production of positive electrode active material A7 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- baking was performed at 690 ° C. for 5 hours.
- it was fired at 925 ° C. for 6 hours in an air atmosphere to obtain a target positive electrode active material A7, that is, lithium-nickel cobalt manganese composite oxide A7.
- the secondary particle diameter of the positive electrode active material A7 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A7 were 936 mm and 543 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.036 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 2.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.7 ⁇ m.
- Example 8 Production of positive electrode active material A8 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- baking was performed at 690 ° C. for 5 hours.
- firing was performed at 925 ° C. for 6 hours in an air atmosphere to obtain a target positive electrode active material A8, that is, lithium-nickel cobalt manganese composite oxide A8.
- the secondary particle diameter of the positive electrode active material A8 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A8 were 947 mm and 550 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.034 cm 3 / g.
- the BET specific surface area was 2.1 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.6 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 9 Production of positive electrode active material A9 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A9 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A9 were 875 mm and 530 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.035 cm 3 / g.
- the BET specific surface area was 2.3 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 2.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.8 ⁇ m.
- Example 10 Production of positive electrode active material A10 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A10 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A10 were 885 mm and 533 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.034 cm 3 / g.
- the BET specific surface area was 2.3 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.6 ⁇ m.
- Example 11 Production of positive electrode active material A11 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A11 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A11 were 895 mm and 565 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.032 cm 3 / g.
- the BET specific surface area was 2.3 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.7 ⁇ m.
- Example 12 Production of positive electrode active material A12 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A12 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A12 were 915 mm and 550 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.032 cm 3 / g.
- the BET specific surface area was 2.1 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.6 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.5 ⁇ m.
- Example 13 Production of positive electrode active material A13 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A13 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A13 were 875 mm and 530 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.034 cm 3 / g.
- the BET specific surface area was 2.3 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.3 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.9 ⁇ m.
- Example 14 Production of positive electrode active material A14 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A14 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A14 were 866 ⁇ and 533 ⁇ , respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.035 cm 3 / g. Further, the BET specific surface area was 2.5 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 2.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.8 ⁇ m.
- Example 15 Production of positive electrode active material A15 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A15 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A15 were 905 mm and 558 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.033 cm 3 / g.
- the BET specific surface area was 2.1 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.2 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.9 ⁇ m.
- Example 16 Production of positive electrode active material A16 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A16 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A16 were 895 mm and 550 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.033 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 2.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.8 ⁇ m.
- Example 17 Production of positive electrode active material A17 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A17 was 3.3 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A17 were 970 mm and 572 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.027 cm 3 / g. Moreover, the BET specific surface area was 1.9 m ⁇ 2 > / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.8 ⁇ m.
- Example 18 Production of positive electrode active material A18 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- baking was performed at 690 ° C. for 5 hours.
- the resultant was fired at 925 ° C. for 6 hours in an air atmosphere to obtain a target positive electrode active material A18, that is, lithium-nickel cobalt manganese composite oxide A18.
- the secondary particle diameter of the positive electrode active material A18 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A18 were 959 mm and 547 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.031 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.7 ⁇ m.
- Example 19 Production of positive electrode active material A19 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- baking was performed at 690 ° C. for 5 hours.
- firing was performed at 925 ° C. for 6 hours in an air atmosphere to obtain a target positive electrode active material A19, that is, lithium-nickel cobalt manganese composite oxide A19.
- the secondary particle diameter of the positive electrode active material A19 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A19 were 915 mm and 543 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.034 cm 3 / g.
- the BET specific surface area was 2.1 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.6 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.5 ⁇ m.
- Example 20 Production of positive electrode active material A20 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- baking was performed at 690 ° C. for 5 hours.
- firing was performed at 925 ° C. for 6 hours in an air atmosphere to obtain a target positive electrode active material A20, that is, lithium-nickel cobalt manganese composite oxide A20.
- the secondary particle diameter of the positive electrode active material A20 was 3.1 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A20 were 936 mm and 569 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.033 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressurization test conditions is 2.4 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.7 ⁇ m.
- Example 21 Production of positive electrode active material A21 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- a LiOH aqueous solution in which WO 3 was dissolved at 61 g / L was prepared.
- the secondary particle diameter of the positive electrode active material A21 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A21 were 875 mm and 496 mm, respectively.
- the maximum pore peak was at 90 nm, and the pore volume in the range of 10 nm to 200 nm was 0.043 cm 3 / g.
- the BET specific surface area was 2.4 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions was 2.7 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.5 ⁇ m.
- Example 22 Production of positive electrode active material A22 In the same manner as in Example 6, a nickel cobalt manganese composite hydroxide was obtained.
- the secondary particle diameter of the positive electrode active material A22 was 3.2 ⁇ m.
- the crystallite sizes calculated from the peak A and the peak B of the positive electrode active material A22 were 936 mm and 569 mm, respectively.
- the maximum pore peak was at 108 nm, and the pore volume in the range of 10 nm to 200 nm was 0.035 cm 3 / g. Further, the BET specific surface area was 2.2 m 2 / g.
- Secondary particle diameter after pressurization of the positive electrode active material The secondary particle diameter after the pressurization test of the positive electrode active material under the pressure test conditions is 2.5 ⁇ m, and the change in the secondary particle diameter ( ⁇ D 50 ) was 0.7 ⁇ m.
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
本願は、2015年6月2日に、日本に出願された特願2015-112440号に基づき優先権を主張し、その内容をここに援用する。
(1)組成式Li[Lix(NiαCoβMnγMδ)1-x]O2で表される。
[構造式(1)中、0≦x≦0.10、0.30<α≦0.34、0.30<β≦0.34、0.32≦γ<0.40、0≦δ≦0.10、β<γ、δ+α+β+γ=1であり、MはFe、Cu、Ti、Mg、Al、W、Zn、Sn、Zr、Ga及びVからなる群より選択される1種以上の金属を表す。]
(2)前記正極活物質の二次粒子径が2μm以上10μm以下である。
(3)前記正極活物質は、水銀圧入法によって得られた細孔分布において、細孔径が90nm以上150nm以下の範囲に、細孔ピークの極大値を有する。
本発明の第1の態様のリチウム二次電池用正極活物質は、少なくともニッケル、コバルト及びマンガンを含み、層状構造を有するリチウム二次電池用正極活物質であって、下記要件(1)、(2)及び(3)を満たすことを特徴とするリチウム二次電池用正極活物質である。
(1)組成式Li[Lix(NiαCoβMnγMδ)1-x]O2で表される。
[構造式(1)中、0≦x≦0.10、0.30<α≦0.34、0.30<β≦0.34、0.32≦γ<0.40、0≦δ≦0.10、β<γ、δ+α+β+γ=1であり、MはFe、Cu、Ti、Mg、Al、W、Zn、Sn、Zr、Ga及びVからなる群より選択される1種以上の金属を表す。]
(2)前記正極活物質の二次粒子径が2μm以上10μm以下である。
(3)前記正極活物質は、水銀圧入法によって得られた細孔分布において、細孔径が90nm以上150nm以下の範囲に、細孔ピークの極大値を有する。
前記組成式中、αは0.30<α<0.33が好ましく、0.30<α≦0.32がより好ましい。
前記組成式中、γは0.33<γ<0.40が好ましく、0.33<γ≦0.38がより好ましい。
本発明の第1の態様のリチウム二次電池用正極活物質に用いられるリチウム金属複合酸化物の結晶構造は、層状構造である。該層状構造は、六方晶型の結晶構造または単斜晶型の結晶構造であることがより好ましい。
本発明のリチウム二次電池用正極活物質の粒子形態は、一次粒子が凝集して形成された二次粒子を含み、一次粒子と一次粒子が凝集して形成された二次粒子との混合物であってもよい。
本発明においてリチウム二次電池用正極活物質の一次粒子径は、0.1μm以上1μm以下が好ましい。
一次粒子の平均粒子径は、SEMで観察することにより、測定することができる。
本実施形態において、一次粒子が凝集して形成された二次粒子径は、2μm以上10μm以下である。
二次粒子径の下限値は2.5μmであることがより好ましく、3μmであることが更に好ましい。二次粒子径の上限値は、8μmがより好ましく、7μmが更に好ましく、6μmがとりわけ好ましい。二次粒子径の上限値と下限値は任意に組み合わせることができる。二次粒子径の上限値と下限値の組み合わせとしては、2.5μm以上7μm以下であることが好ましく、3.5μm以上5.0μm以下であることがより好ましい。
二次粒子径が上記の範囲であると、正極活物質を加圧した際の潰れが防止され、加圧時のロール等に正極活物質粉が付着することを防止できる。
本発明の第1の態様のリチウム二次電池用正極活物質は、水銀圧入法によって得られた細孔分布において、細孔径が90nm以上150nm以下の範囲に細孔ピークの極大値を有する。
細孔径が上記上限値以下であると、電極にした際に高い充填率とすることができる。このため、正極活物質粒子の潰れが防止できる。
細孔径が上記下限値以上であると、正極活物質と電解液の接触界面が低下することなく、電池抵抗が減少し、高い出力特性を維持できる。
D=-4σ×cosθ/P ・・・(A)
また、本実施形態の正極活物質のBET比表面積は、1.5m2/g以上2.5m2/g以下であることが好ましい。BET比表面積が上記の範囲であると、正極活物質を加圧した際に、正極活物質粒子の潰れがさらに防止される。
リチウム金属複合酸化物のBET比表面積は、1.6m2/g以上であることが好ましく、1.7m2/g以上であることが好ましく、1.8m2/g以上であることが更に好ましい。また、充填性の観点で好ましいBET比表面積は2.45m2/g以下であることが好ましく、2.4m2/g以下であることが好ましく、2.3m2/g以下であることが好ましい。BET比表面積の上限値と下限値は任意に組み合わせることができる。
リチウム金属複合酸化物のBET比表面積が上記の範囲であると、正極活物質を加圧した際の、正極活物質粒子の潰れ防止にさらに寄与できる。
リチウム金属複合酸化物は、CuKα線を使用した粉末X線回折測定において、2θ=18.7±1°の範囲内のピーク(以下、ピークAと呼ぶこともある)における結晶子サイズが100~1200Åの範囲であり、かつ、2θ=44.6±1°の範囲内のピーク(以下、ピークBと呼ぶこともある)における結晶子サイズが100~800Åであることが好ましい。ピークAにおける結晶子サイズの上限値は、1100Åが好ましく、1000Åであることがより好ましく、950Åであることが更に好ましい。ピークAにおける結晶子サイズの下限値は、400Åであることが好ましく、500Åであることがより好ましく、600Åであることが更に好ましい。ピークBにおける結晶子サイズの上限値は、750Åが好ましく、700Åであることがより好ましく、650Åであることが更に好ましい。ピークBにおける結晶子サイズの下限値は、300Åであることが好ましく、400Åであることがより好ましく、500Åであることが更に好ましい。ピークA、ピークBそれぞれにおける結晶子サイズの上限値と下限値は任意に組み合わせることができる。上記の好ましいピークAにおける結晶子サイズとピークBにおける結晶子サイズは任意に組み合わせることができる。これにより、得られるリチウム二次電池のサイクル特性を良好なものとすることができる。
また、本実施形態の正極活物質は二次粒子内部に空隙を有する粒子が含有されることが好ましい。該空隙とは、正極活物質粒子の断面を観察したとき、該粒子内部に存在する、直径50nm以上の空間を指す。該空隙は一粒子内部に二個以上存在することが好ましく、五個以上存在することがより好ましく、十個以上存在することが更に好ましい。該空隙を有することにより、得られるリチウム二次電池の高い電流レートにおける放電容量を高めることができる。また、空隙の直径は60nm以上1000nm以下の範囲であることが好ましく、70nm以上800nm以下の範囲であることがより好ましく、75nm以上600nm以下の範囲であることが更に好ましい。空隙の直径が上記の範囲であることにより、該正極活物質粒子を用いた電極の密度が高まり、高容量のリチウム二次電池が得られる。
本実施形態において、リチウム二次電池用正極活物質のタップかさ密度は、電極密度が高いリチウム二次電池を得る意味で、1.20g/mL以上であることが好ましく、1.25g/mL以上であることがより好ましく、1.30g/mL以上であることが更に好ましい。また、電解液の含浸性が高い電極を得る意味で、1.80g/mL以下であることが好ましく、1.65g/mL以下であることがより好ましく、1.50g/mL以下であることが更に好ましい。
タップかさ密度はJIS R 1628-1997に基づいて測定することができる。
なお、本明細書において、「重装密度」とは上記JIS R 1628-1997におけるタップかさ密度に該当する。
さらに本実施形態のリチウム二次電池用正極活物質は、電極にした際の正極活物質の割れや潰れを抑制する観点から、細孔径の小さな細孔容積を有することが好ましい。つまり、前記二次粒子の集合体が有する空隙および二次粒子間空隙の総体積をVc(Vc(mL/g)=1/(タップかさ密度))、細孔分布測定における細孔径が10nmから100nmの範囲の細孔容積の和をVs(mL/g)としたときに、Vcに対するVsの割合(Vs/Vc×100)が4.0%以下であることが好ましく、3.5%以下であることがより好ましく、3.3%以下であることが更に好ましい。また、電解液の含浸性が高いリチウム二次電池用正極活物質を得る意味で、1.0%以上であることが好ましく、1.5%以上であることがより好ましく、1.7%以上であることが更に好ましい。
これに加え、以上のような構成の正極活物質は、電池抵抗が従来よりも優れたものとすることができる。
本発明のリチウム金属複合酸化物を製造するにあたって、まず、リチウム以外の金属、すなわち、Ni、Co及びMnからなる群から構成される少なくとも1種の必須金属、並びに、Fe、Cu、Ti、Mg、Al、W、Zn、Sn、Zr、Ga、Vのうちいずれか1種以上の任意金属を含む金属複合化合物を調製し、当該金属複合化合物を適当なリチウム塩と焼成することが好ましい。金属複合化合物としては、金属複合水酸化物又は金属複合酸化物が好ましい。以下に、正極活物質の製造方法の一例を、金属複合化合物の製造工程と、リチウム金属複合酸化物の製造工程とに分けて説明する。
金属複合化合物は、通常公知の製造法により製造することが可能である。以下、金属として、ニッケル、コバルト及びマンガンを含む金属複合水酸化物を例に、その製造方法を詳述する。
上記金属複合酸化物又は水酸化物を乾燥した後、リチウム塩と混合する。乾燥条件は、特に制限されないが、例えば、金属複合酸化物又は水酸化物が酸化・還元されない条件(酸化物→酸化物、水酸化物→水酸化物)、金属複合水酸化物が酸化される条件(水酸化物→酸化物)、金属複合酸化物が還元される条件(酸化物→水酸化物)のいずれの条件でもよい。酸化・還元がされない条件のためには、窒素、ヘリウム及びアルゴン等の希ガス等の不活性ガスを使用すれば良く、水酸化物が酸化される条件では、酸素又は空気を雰囲気下として行えば良い。また、金属複合酸化物が還元される条件としては、不活性ガス雰囲気下、ヒドラジン、亜硫酸ナトリウム等の還元剤を使用すれば良い。リチウム塩としては、炭酸リチウム、硝酸リチウム、酢酸リチウム、水酸化リチウム、水酸化リチウム水和物、酸化リチウムのうち何れか一つ、または、二つ以上を混合して使用することができる。
金属複合酸化物又は水酸化物の乾燥後に、適宜分級を行っても良い。以上のリチウム塩と金属複合水酸化物とは、最終目的物の組成比を勘案して用いられる。例えば、ニッケルコバルトマンガン複合水酸化物を用いる場合、リチウム塩と当該複合金属水酸化物は、LiNixCoyMnzO2(式中、x+y+z=1)の組成比に対応する割合で用いられる。ニッケルコバルトマンガン複合金属水酸化物及びリチウム塩の混合物を焼成することによって、リチウム-ニッケルコバルトマンガン複合酸化物が得られる。なお、焼成には、所望の組成に応じて乾燥空気、酸素雰囲気、不活性雰囲気等が用いられ、必要ならば複数の加熱工程が実施される。
次いで、リチウム二次電池の構成を説明しながら、上述したリチウム含有複合金属酸化物をリチウム二次電池用正極活物質として用いた本発明の第2の態様のリチウム二次電池用正極、及びこのリチウム二次電池用正極を有する本発明の第3の態様のリチウム二次電池について説明する。
(正極)
本実施形態の正極は、まず正極活物質、導電材およびバインダーを含む正極合剤を調整し、正極合剤を正極集電体に担持させることで製造することができる。
本実施形態の正極が有する導電材としては、炭素材料を用いることができる。炭素材料として黒鉛粉末、カーボンブラック(例えばアセチレンブラック)、繊維状炭素材料などを挙げることができる。カーボンブラックは、微粒で表面積が大きいため、少量を正極合剤中に添加することにより正極内部の導電性を高め、充放電効率および出力特性を向上させることができるが、多く入れすぎるとバインダーによる正極合剤と正極集電体との結着力、および正極合剤内部の結着力がいずれも低下し、かえって内部抵抗を増加させる原因となる。
本実施形態の正極が有するバインダーとしては、熱可塑性樹脂を用いることができる。
この熱可塑性樹脂としては、ポリフッ化ビニリデン(以下、PVdFということがある。)、ポリテトラフルオロエチレン(以下、PTFEということがある。)、四フッ化エチレン・六フッ化プロピレン・フッ化ビニリデン系共重合体、六フッ化プロピレン・フッ化ビニリデン系共重合体、四フッ化エチレン・パーフルオロビニルエーテル系共重合体などのフッ素樹脂;ポリエチレン、ポリプロピレンなどのポリオレフィン樹脂;を挙げることができる。
本実施形態の正極が有する正極集電体としては、Al、Ni、ステンレスなどの金属材料を形成材料とする帯状の部材を用いることができる。なかでも、加工しやすく、安価であるという点でAlを形成材料とし、薄膜状に加工したものが好ましい。
本実施形態においては、上述したリチウム含有複合金属酸化物をリチウム二次電池用正極活物質として用いているため、この加圧成型した際に正極活物質の潰れが防止される。
このため、加圧するためのロール等の部品に正極活物質が粉砕されたことにより生じる正極活物質粉の付着を防止することができる。
正極合剤をペースト化する場合、用いることができる有機溶媒としては、N,N―ジメチルアミノプロピルアミン、ジエチレントリアミンなどのアミン系溶媒;テトラヒドロフランなどのエーテル系溶媒;メチルエチルケトンなどのケトン系溶媒;酢酸メチルなどのエステル系溶媒;ジメチルアセトアミド、N-メチル-2-ピロリドン(以下、NMPということがある。)などのアミド系溶媒;が挙げられる。
(負極)
本実施形態のリチウム二次電池が有する負極は、正極よりも低い電位でリチウムイオンのドープかつ脱ドープが可能であればよく、負極活物質を含む負極合剤が負極集電体に担持されてなる電極、および負極活物質単独からなる電極を挙げることができる。
負極が有する負極活物質としては、炭素材料、カルコゲン化合物(酸化物、硫化物など)、窒化物、金属または合金で、正極よりも低い電位でリチウムイオンのドープかつ脱ドープが可能な材料が挙げられる。
負極が有する負極集電体としては、Cu、Ni、ステンレスなどの金属材料を形成材料とする帯状の部材を挙げることができる。なかでも、リチウムと合金を作り難く、加工しやすいという点で、Cuを形成材料とし、薄膜状に加工したものが好ましい。
本実施形態のリチウム二次電池が有するセパレータとしては、例えば、ポリエチレン、ポリプロピレンなどのポリオレフィン樹脂、フッ素樹脂、含窒素芳香族重合体などの材質からなる、多孔質膜、不織布、織布などの形態を有する材料を用いることができる。また、これらの材質を2種以上用いてセパレータを形成してもよいし、これらの材料を積層してセパレータを形成してもよい。
以下、前記の耐熱多孔層と多孔質フィルムとが互いに積層された積層フィルムについて説明する。
耐熱多孔層が無機粉末から形成されている場合、耐熱多孔層に用いられる無機粉末としては、例えば、金属酸化物、金属窒化物、金属炭化物、金属水酸化物、炭酸塩、硫酸塩などの無機物からなる粉末が挙げられ、これらの中でも、導電性の低い(絶縁体の)無機物からなる粉末が好ましく用いられる。具体的に例示すると、アルミナ、シリカ、二酸化チタンまたは炭酸カルシウムなどからなる粉末が挙げられる。このような無機粉末は、単独で用いてもよいし、2種以上を混合して用いることもできる。
また、無機粉末を構成する粒子のすべてがアルミナ粒子であることがより好ましく、無機粉末を構成する粒子のすべてがアルミナ粒子であり、その一部または全部が略球状のアルミナ粒子であることが更に好ましい。
耐熱多孔層が耐熱樹脂から形成されている場合、耐熱多孔層に用いられる耐熱樹脂としては、ポリアミド、ポリイミド、ポリアミドイミド、ポリカーボネート、ポリアセタール、ポリサルホン、ポリフェニレンサルファイド、ポリエーテルケトン、芳香族ポリエステル、ポリエーテルサルホンおよびポリエーテルイミドを挙げることができる。積層フィルムの耐熱性をより高めるためには、ポリアミド、ポリイミド、ポリアミドイミド、ポリエーテルサルホンおよびポリエーテルイミドが好ましく、より好ましくは、ポリアミド、ポリイミドまたはポリアミドイミドである。
また、耐熱多孔層が耐熱樹脂とフィラーとを含んで形成されている場合、耐熱樹脂は、上記第2の耐熱多孔層に用いられる耐熱樹脂と同じものを使用することができる。フィラーは、有機粉末、無機粉末またはこれらの混合物からなる群から選ばれる1種以上を用いることができる。フィラーを構成する粒子は、その平均粒子径が、0.01μm以上1μm以下であることが好ましい。
本実施形態のリチウム二次電池が有する電解液は、電解質および有機溶媒を含有する。
これに加え、以上のような構成の正極は、電池抵抗が従来よりも優れたものとすることができる。
これに加え、電池抵抗が従来よりも優れたものとすることができる。
1.リチウム二次電池用正極活物質の組成分析
後述の方法で製造されるリチウム金属複合酸化物の組成分析は、得られたリチウム金属複合酸化物の粉末を塩酸に溶解させた後、誘導結合プラズマ発光分析装置(エスアイアイ・ナノテクノロジー株式会社製、SPS3000)を用いて行った。
測定するリチウム金属複合酸化物の粒子を、サンプルステージの上に貼った導電性シート上に載せ、日本電子株式会社製JSM-5510を用いて、加速電圧が20kVの電子線を照射してSEM観察を行った。SEM観察により得られた画像(SEM写真)から任意に50個の一次粒子を抽出し、それぞれの1次粒子について、一次粒子の投影像を一定方向から引いた平行線ではさんだ平行線間の距離(定方向径)を一次粒子の粒子径として測定した。得られた粒子径の算術平均値を、リチウム金属複合酸化物の平均一次粒子径とした。
測定するリチウム金属複合酸化物の粉末0.1gを、0.2質量%ヘキサメタりん酸ナトリウム水溶液50mlに投入し、該粉末を分散させた分散液を得た。得られた分散液についてマルバーン社製マスターサイザー2000(レーザー回折散乱粒度分布測定装置)を用いて、粒度分布を測定し、体積基準の累積粒度分布曲線を得た。得られた累積粒度分布曲線において、50%累積時の微小粒子側から見た粒子径(D50)の値を、リチウム金属複合酸化物の平均二次粒子径とした。
リチウム金属複合酸化物の粉末X線回折測定は、X線回折装置(X‘Prt PRO、PANalytical社)を用いて行った。得られたリチウム金属複合酸化物を専用の基板に充填し、Cu-Kα線源を用いて、回折角2θ=10°~90°の範囲にて測定を行うことで、粉末X線回折図形を得た。粉末X線回折パターン総合解析ソフトウェアJADE5を用い、該粉末X線回折図形からピークAに対応するピークの半価幅およびピークBに対応するピークの半値幅を得て、Scherrer式により、結晶子径を算出した。
ピークA : 2θ=18.7±1°
ピークB : 2θ=44.6±1°
前処理としてリチウム金属複合酸化物を120℃、4時間、恒温乾燥した。オートポアIII9420(Micromeritics 社製)を用いて、下記の測定条件にて細孔分布測定を実施した。なお水銀の表面張力は480dynes/cm、水銀と試料の接触角は140°とした。
測定温度 : 25℃
測定圧力 : 1.07psia~59256.3psia
測定するリチウム金属複合酸化物の粉末1gを窒素雰囲気中、150℃で15分間乾燥させた後、マイクロメリティックス製フローソーブII2300を用いて測定した。
測定するリチウム金属複合酸化物の粉末0.5gを、φ13mmの金型に充填し、一軸プレス機を用い50MPaでプレスした。その後金型から粉末を取り出し、上記3と同様の手法にて、プレス(加圧)後のリチウム二次電池用正極活物質の二次粒子径を測定した。
本実施例において、加圧前後の二次粒子径の変化(ΔD50)が1.0μm以上であると、正極活物質が潰れてしまっていることを示す。
1.正極活物質A1の製造
攪拌機およびオーバーフローパイプを備えた反応槽内に水を入れた後、水酸化ナトリウム水溶液を添加した。
得られた正極活物質A1の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.09:0.315:0.330:0.355であった。この時、xは、0.04であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、1.7μmであり、二次粒子径の変化(ΔD50)は0.4μmであった。
1.正極活物質A2の製造
反応槽内の溶液のpHを11.7に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、32.5m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物A2を得た。
得られた正極活物質A2の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.13:0.315:0.330:0.355であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、4.0μmであり、二次粒子径の変化(ΔD50)は0.3μmであった。
1.正極活物質A3の製造
反応槽内の溶液のpHを11.3に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、29.7m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物A3を得た。
得られた正極活物質A3の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.12:0.315:0.330:0.355であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、4.6μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質A4の製造
反応槽内の溶液の温度を40℃に、pHを11.3に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、22.1m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物A4を得た。
得られた正極活物質A4の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.10:0.315:0.330:0.355であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、7.6μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質A5の製造
反応槽内の溶液の温度を40℃に、pHを11.1に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、18.6m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物A5を得た。
得られた正極活物質A5の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.10:0.315:0.330:0.355であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、9.2μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質B1の製造
反応槽内の溶液の温度を30℃に、pHを12.7に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、46.6m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B1を得た。
得られた正極活物質B1の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.09:0.315:0.330:0.355であった。この時、xは、0.04であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、0.4μmであり、二次粒子径の変化(ΔD50)は1.1μmであった。
1.正極活物質B2の製造
反応槽内の溶液の温度を30℃に、pHを12.0に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、19.2m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B2を得た。
得られた正極活物質B2の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.10:0.315:0.330:0.355であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、10.2μmであり、二次粒子径の変化(ΔD50)は1.3μmであった。
1.正極活物質B3の製造
硫酸ニッケル水溶液と硫酸コバルト水溶液と硫酸マンガン水溶液とを、ニッケル原子とコバルト原子とマンガン原子との原子比が0.334:0.333:0.333となるように混合して混合原料液を調整し、反応槽内の溶液の温度を30℃に、pHを12.4に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、21.3m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B3を得た。
得られた正極活物質B3の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.11:0.334:0.333:0.333であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.0μmであり、二次粒子径の変化(ΔD50)は1.0μmであった。
1.正極活物質B4の製造
硫酸ニッケル水溶液と硫酸コバルト水溶液と硫酸マンガン水溶液とを、ニッケル原子とコバルト原子とマンガン原子との原子比が0.334:0.333:0.333となるように混合して混合原料液を調整し、反応槽内の溶液の温度を30℃に、pHを11.1に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、11.6m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B4を得た。
得られた正極活物質B4の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.10:0.334:0.333:0.333であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、7.8μmであり、二次粒子径の変化(ΔD50)は1.1μmであった。
1.正極活物質B5の製造
硫酸ニッケル水溶液と硫酸コバルト水溶液と硫酸マンガン水溶液とを、ニッケル原子とコバルト原子とマンガン原子との原子比が0.334:0.333:0.333となるように混合して混合原料液を調整し、反応槽内の溶液の温度を40℃に、pHを11.0に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、10.2m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B5を得た。
得られた正極活物質B5の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.10:0.334:0.333:0.333であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、10.5μmであり、二次粒子径の変化(ΔD50)は1.3μmであった。
1.正極活物質B6の製造
硫酸ニッケル水溶液と硫酸コバルト水溶液と硫酸マンガン水溶液とを、ニッケル原子とコバルト原子とマンガン原子との原子比が0.334:0.333:0.333となるように混合して混合原料液を調整し、反応槽内の溶液のpHを11.1に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、22.3m2/gであった。
実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B6を得た。
得られた正極活物質B6の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.11:0.334:0.333:0.333であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、3.2μmであり、二次粒子径の変化(ΔD50)は1.1μmであった。
1.正極活物質B7の製造
硫酸ニッケル水溶液と硫酸コバルト水溶液と硫酸マンガン水溶液とを、ニッケル原子とコバルト原子とマンガン原子との原子比が0.35:0.30:0.35となるように混合して混合原料液を調整し、反応槽内の溶液のpHを11.4に設定したこと以外は実施例1と同様の操作を行い、ニッケルコバルトマンガン複合水酸化物を得た。このニッケルコバルトマンガン複合水酸化物のBET比表面積は、20.0m2/gであった。実施例1と同様にしてリチウム-ニッケルコバルトマンガン複合酸化物B7を得た。
得られた正極活物質B7の組成分析を行ったところ、Li:Ni:Co:Mnのモル比は、1.11:0.35:0.30:0.35であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、3.2μmであり、二次粒子径の変化(ΔD50)は1.0μmであった。
これに対し、比較例1~7のリチウム金属複合酸化物を用いた正極活物質は、加圧前後の二次粒子径の変化(ΔD50)が1.0μm以上と大きく、加圧時に正極活物質が潰れてしまった。
1.正極活物質A6の製造
攪拌機およびオーバーフローパイプを備えた反応槽内に水を入れた後、水酸化ナトリウム水溶液を添加した。
得られた正極活物質A6の組成分析を行ったところ、Li:Ni:Co:Mn:Mgのモル比は、1.13:0.317:0.329:0.353:0.001であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質A7の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A7の組成分析を行ったところ、Li:Ni:Co:Mn:Mgのモル比は、1.14:0.316:0.327:0.353:0.004であった。この時、xは、0.07であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.4μmであり、二次粒子径の変化(ΔD50)は0.7μmであった。
1.正極活物質A8の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A8の組成分析を行ったところ、Li:Ni:Co:Mn:Mgのモル比は、1.14:0.306:0.321:0.344:0.029であった。この時、xは、0.07であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.6μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質A9の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A9の組成分析を行ったところ、Li:Ni:Co:Mn:Alのモル比は、1.13:0.317:0.328:0.354:0.001であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.4μmであり、二次粒子径の変化(ΔD50)は0.8μmであった。
1.正極活物質A10の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A10の組成分析を行ったところ、Li:Ni:Co:Mn:Alのモル比は、1.13:0.316:0.327:0.352:0.005であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.6μmであった。
1.正極活物質A11の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A11の組成分析を行ったところ、Li:Ni:Co:Mn:Alのモル比は、1.12:0.308:0.319:0.344:0.029であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.7μmであった。
1.正極活物質A12の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A12の組成分析を行ったところ、Li:Ni:Co:Mn:Zrのモル比は、1.13:0.315:0.330:0.354:0.001であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.6μmであり、二次粒子径の変化(ΔD50)は0.5μmであった。
1.正極活物質A13の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A13の組成分析を行ったところ、Li:Ni:Co:Mn:Zrのモル比は、1.13:0.315:0.328:0.352:0.005であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.3μmであり、二次粒子径の変化(ΔD50)は0.9μmであった。
1.正極活物質A14の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A14の組成分析を行ったところ、Li:Ni:Co:Mn:Zrのモル比は、1.10:0.308:0.318:0.342:0.032であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.4μmであり、二次粒子径の変化(ΔD50)は0.8μmであった。
1.正極活物質A15の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A15の組成分析を行ったところ、Li:Ni:Co:Mn:Vのモル比は、1.13:0.317:0.329:0.353:0.001であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.2μmであり、二次粒子径の変化(ΔD50)は0.9μmであった。
1.正極活物質A16の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A16の組成分析を行ったところ、Li:Ni:Co:Mn:Vのモル比は、1.12:0.314:0.328:0.352:0.005であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.4μmであり、二次粒子径の変化(ΔD50)は0.8μmであった。
1.正極活物質A17の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A17の組成分析を行ったところ、Li:Ni:Co:Mn:Vのモル比は、1.07:0.308:0.318:0.343:0.030であった。この時、xは、0.03であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.8μmであった。
1.正極活物質A18の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A18の組成分析を行ったところ、Li:Ni:Co:Mn:Snのモル比は、1.14:0.317:0.329:0.353:0.001であった。この時、xは、0.07であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.7μmであった。
1.正極活物質A19の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A19の組成分析を行ったところ、Li:Ni:Co:Mn:Snのモル比は、1.13:0.315:0.328:0.352:0.005であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.6μmであり、二次粒子径の変化(ΔD50)は0.5μmであった。
1.正極活物質A20の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A20の組成分析を行ったところ、Li:Ni:Co:Mn:Snのモル比は、1.10:0.308:0.320:0.344:0.028であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.4μmであり、二次粒子径の変化(ΔD50)は0.7μmであった。
1.正極活物質A21の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A21の組成分析を行ったところ、Li:Ni:Co:Mn:Wのモル比は、1.11:0.315:0.329:0.351:0.005であった。この時、xは、0.05であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.7μmであり、二次粒子径の変化(ΔD50)は0.5μmであった。
1.正極活物質A22の製造
実施例6と同様にしてニッケルコバルトマンガン複合水酸化物を得た。
得られた正極活物質A22の組成分析を行ったところ、Li:Ni:Co:Mn:Wのモル比は、1.13:0.317:0.329:0.353:0.001であった。この時、xは、0.06であった。
前記加圧試験条件にて正極活物質の加圧試験を実施した後の二次粒子径は、2.5μmであり、二次粒子径の変化(ΔD50)は0.7μmであった。
Claims (9)
- 少なくともニッケル、コバルト及びマンガンを含み、層状構造を有するリチウム二次電池用正極活物質であって、下記要件(1)、(2)及び(3)を満たすことを特徴とするリチウム二次電池用正極活物質。
(1)組成式Li[Lix(NiαCoβMnγMδ)1-x]O2で表される。
[組成式(1)中、0≦x≦0.10、0.30<α≦0.34、0.30<β≦0.34、0.32≦γ<0.40、0≦δ≦0.10、β<γ、δ+α+β+γ=1であり、MはFe、Cu、Ti、Mg、Al、W、Zn、Sn、Zr、Ga及びVからなる群より選択される1種以上の金属を表す。]
(2)前記正極活物質の二次粒子径が2μm以上10μm以下である。
(3)前記正極活物質は、水銀圧入法によって得られた細孔分布において、細孔径が90nm以上150nm以下の範囲に、細孔ピークの極大値を有する。 - 前記二次粒子径が2.5μm以上7μm以下である請求項1に記載のリチウム二次電池用正極活物質。
- BET比表面積が1.5m2/g以上2.5m2/g以下である請求項1又は2に記載のリチウム二次電池用正極活物質。
- 水銀圧入法によって得られた細孔分布において、10nm以上200nm以下の範囲の細孔容積が0.025cm3/g以上0.045cm3/g以下である請求項1又は2に記載のリチウム二次電池用正極活物質。
- 水銀圧入法によって得られた細孔分布において、10nm以上200nm以下の範囲の細孔容積が0.025cm3/g以上0.045cm3/g以下である請求項3に記載のリチウム二次電池用正極活物質。
- 請求項1又は2に記載のリチウム二次電池用正極活物質を有するリチウム二次電池用正極。
- 請求項3に記載のリチウム二次電池用正極活物質を有するリチウム二次電池用正極。
- 請求項4に記載のリチウム二次電池用正極活物質を有するリチウム二次電池用正極。
- 請求項6に記載のリチウム二次電池用正極を有するリチウム二次電池。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201680030998.7A CN107615530B (zh) | 2015-06-02 | 2016-06-02 | 锂二次电池用正极活性物质、锂二次电池用正极和锂二次电池 |
JP2017522257A JP6768647B2 (ja) | 2015-06-02 | 2016-06-02 | 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 |
US15/577,727 US10756343B2 (en) | 2015-06-02 | 2016-06-02 | Positive-electrode active material for lithium secondary cell, positive electrode for lithium secondary cell, and lithium secondary cell |
KR1020177035695A KR102566584B1 (ko) | 2015-06-02 | 2016-06-02 | 리튬 2 차 전지용 정극 활물질, 리튬 2 차 전지용 정극 및 리튬 2 차 전지 |
EP16803470.0A EP3306713B1 (en) | 2015-06-02 | 2016-06-02 | Positive-electrode active material for lithium secondary cell, positive electrode for lithium secondary cell, and lithium secondary cell |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015-112440 | 2015-06-02 | ||
JP2015112440 | 2015-06-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2016195036A1 true WO2016195036A1 (ja) | 2016-12-08 |
Family
ID=57440317
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/066467 WO2016195036A1 (ja) | 2015-06-02 | 2016-06-02 | 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 |
Country Status (6)
Country | Link |
---|---|
US (1) | US10756343B2 (ja) |
EP (1) | EP3306713B1 (ja) |
JP (1) | JP6768647B2 (ja) |
KR (1) | KR102566584B1 (ja) |
CN (1) | CN107615530B (ja) |
WO (1) | WO2016195036A1 (ja) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6368022B1 (ja) * | 2017-05-31 | 2018-08-01 | 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 |
US10149425B2 (en) | 2013-10-15 | 2018-12-11 | Lemken Gmbh & Co. Kg. | Seed meter for a single-grain seeder |
JP2019040675A (ja) * | 2017-08-22 | 2019-03-14 | 住友金属鉱山株式会社 | 非水系二次電池用正極活物質の製造方法及び遷移金属化合物 |
WO2019098384A1 (ja) * | 2017-11-20 | 2019-05-23 | 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 |
CN110462897A (zh) * | 2017-03-31 | 2019-11-15 | 住友化学株式会社 | 锂二次电池用正极活性物质、锂二次电池用正极以及锂二次电池 |
WO2020110260A1 (ja) | 2018-11-29 | 2020-06-04 | 株式会社 東芝 | 電極、電池、及び電池パック |
US11011741B2 (en) | 2016-12-07 | 2021-05-18 | Sumitomo Chemical Company, Limited | Positive electrode active material for lithium secondary batteries, positive electrode for lithium secondary batteries, and lithium secondary battery |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20240060862A (ko) * | 2016-04-27 | 2024-05-08 | 캠엑스 파워 엘엘씨 | 나노-결정을 포함하는 다결정질 레이어드 금속 옥사이드 |
JP6523508B1 (ja) * | 2018-03-30 | 2019-06-05 | 住友化学株式会社 | リチウム複合金属化合物、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、リチウム二次電池、及びリチウム複合金属化合物の製造方法 |
US11424449B2 (en) | 2019-01-25 | 2022-08-23 | Camx Power Llc | Stable cathode materials |
WO2023136609A1 (ko) * | 2022-01-11 | 2023-07-20 | 주식회사 엘지에너지솔루션 | 리튬 이차전지용 양극 및 이의 제조 방법 |
CN115084508B (zh) * | 2022-08-23 | 2023-01-31 | 欣旺达电动汽车电池有限公司 | 正极活性材料、电池及其制备方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005123179A (ja) * | 2003-09-26 | 2005-05-12 | Mitsubishi Chemicals Corp | リチウム二次電池正極材用リチウム複合酸化物粒子、並びに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 |
JP2012054135A (ja) * | 2010-09-02 | 2012-03-15 | Hitachi Maxell Energy Ltd | 電気化学素子用電極およびリチウムイオン二次電池 |
JP2012234766A (ja) * | 2011-05-09 | 2012-11-29 | Sony Corp | リチウムイオン二次電池用活物質、リチウムイオン二次電池用電極、リチウムイオン二次電池、電子機器、電動工具、電動車両および電力貯蔵システム |
JP2015018678A (ja) * | 2013-07-10 | 2015-01-29 | 株式会社田中化学研究所 | リチウム二次電池用正極活物質、正極および二次電池 |
JP2015041600A (ja) * | 2013-08-23 | 2015-03-02 | Agcセイミケミカル株式会社 | リチウムイオン二次電池用のリチウム含有複合酸化物の製造方法 |
Family Cites Families (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10162860A (ja) | 1996-11-29 | 1998-06-19 | Matsushita Electric Ind Co Ltd | 非水電解液二次電池 |
JP4038868B2 (ja) | 1997-03-26 | 2008-01-30 | 住友化学株式会社 | パラアラミド系多孔質フィルムおよびそれを用いた電池用セパレーターとリチウム二次電池 |
JP3175730B2 (ja) | 1998-04-27 | 2001-06-11 | 住友化学工業株式会社 | 非水電解質電池セパレーターとリチウム二次電池 |
TW460505B (en) | 1998-04-27 | 2001-10-21 | Sumitomo Chemical Co | Separator for nonaqueous electrolyte battery and lithium secondary battery made from the same |
JP2001076724A (ja) | 1999-09-02 | 2001-03-23 | Sumitomo Metal Ind Ltd | リチウム電池用正極材料とその製造方法 |
JP2002201028A (ja) | 2000-11-06 | 2002-07-16 | Tanaka Chemical Corp | 高密度コバルトマンガン共沈水酸化ニッケル及びその製造法 |
US20020053663A1 (en) | 2000-11-06 | 2002-05-09 | Tanaka Chemical Corporation | High density cobalt-manganese coprecipitated nickel hydroxide and process for its production |
JP4556377B2 (ja) | 2001-04-20 | 2010-10-06 | 株式会社Gsユアサ | 正極活物質およびその製造方法、非水電解質二次電池用正極、並びに、非水電解質二次電池 |
US7393476B2 (en) | 2001-11-22 | 2008-07-01 | Gs Yuasa Corporation | Positive electrode active material for lithium secondary cell and lithium secondary cell |
US8241790B2 (en) | 2002-08-05 | 2012-08-14 | Panasonic Corporation | Positive electrode active material and non-aqueous electrolyte secondary battery containing the same |
WO2005031899A1 (ja) | 2003-09-26 | 2005-04-07 | Mitsubishi Chemical Corporation | リチウム二次電池正極材用リチウム複合酸化物粒子、並びに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 |
CN100492728C (zh) | 2003-09-26 | 2009-05-27 | 三菱化学株式会社 | 用于锂二次电池正极材料的锂复合氧化物颗粒、使用该颗粒的锂二次电池正极以及锂二次电池 |
JP4781004B2 (ja) | 2005-04-28 | 2011-09-28 | パナソニック株式会社 | 非水電解液二次電池 |
CN102044673B (zh) | 2006-04-07 | 2012-11-21 | 三菱化学株式会社 | 锂二次电池正极材料用锂镍锰钴系复合氧化物粉体 |
JP4591717B2 (ja) | 2006-09-22 | 2010-12-01 | 三菱化学株式会社 | リチウム二次電池正極材料用リチウムニッケルマンガンコバルト系複合酸化物粉体、その製造方法、及び噴霧乾燥粉体、並びに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 |
JP2010278015A (ja) | 2006-09-22 | 2010-12-09 | Mitsubishi Chemicals Corp | リチウム二次電池正極材料用リチウムニッケルマンガンコバルト系複合酸化物粉体、その製造方法、及び噴霧乾燥粉体、並びに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 |
JP4613943B2 (ja) | 2006-11-10 | 2011-01-19 | 三菱化学株式会社 | リチウム遷移金属系化合物粉体、その製造方法、及びその焼成前躯体となる噴霧乾燥体、並びに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 |
WO2008099831A1 (ja) | 2007-02-13 | 2008-08-21 | Nec Corporation | 鍵生成装置、鍵導出装置、暗号化装置、復号化装置、方法、及び、プログラム |
JP5172835B2 (ja) | 2007-06-21 | 2013-03-27 | Agcセイミケミカル株式会社 | リチウム含有複合酸化物粉末及びその製造方法 |
CN102769130A (zh) | 2007-09-04 | 2012-11-07 | 三菱化学株式会社 | 锂过渡金属类化合物粉末 |
EP2065887A1 (en) | 2007-11-30 | 2009-06-03 | Hitachi Global Storage Technologies Netherlands B.V. | Method for manufacturing magnetic disk unit |
WO2009099158A1 (ja) | 2008-02-06 | 2009-08-13 | Agc Seimi Chemical Co., Ltd. | リチウムイオン二次電池正極活物質用の造粒体粉末の製造方法 |
CN102203987B (zh) | 2008-10-27 | 2014-04-09 | 花王株式会社 | 锂复合氧化物烧结体 |
JP5325888B2 (ja) | 2009-04-10 | 2013-10-23 | 日立マクセル株式会社 | 電極用活物質、非水二次電池用電極および非水二次電池 |
CA2778286C (en) | 2009-10-22 | 2018-07-24 | Toda Kogyo Corporation | Nickel-cobalt-manganese-based compound particles and process for producing the nickel-cobalt-manganese-based compound particles, lithium composite oxide particles and process for producing the lithium composite oxide particles, and non-aqueous electrolyte secondary battery |
CN102714313A (zh) | 2010-01-08 | 2012-10-03 | 三菱化学株式会社 | 锂二次电池正极材料用粉末及其制造方法、以及使用其的锂二次电池用正极及锂二次电池 |
EP2555287B1 (en) | 2010-04-01 | 2018-05-02 | Mitsubishi Chemical Corporation | Positive electrode material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery |
JP5447248B2 (ja) | 2010-07-14 | 2014-03-19 | 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およびその製造方法、ならびにこの正極活物質を用いた非水系電解質二次電池 |
-
2016
- 2016-06-02 KR KR1020177035695A patent/KR102566584B1/ko active IP Right Grant
- 2016-06-02 JP JP2017522257A patent/JP6768647B2/ja active Active
- 2016-06-02 EP EP16803470.0A patent/EP3306713B1/en active Active
- 2016-06-02 US US15/577,727 patent/US10756343B2/en active Active
- 2016-06-02 CN CN201680030998.7A patent/CN107615530B/zh active Active
- 2016-06-02 WO PCT/JP2016/066467 patent/WO2016195036A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005123179A (ja) * | 2003-09-26 | 2005-05-12 | Mitsubishi Chemicals Corp | リチウム二次電池正極材用リチウム複合酸化物粒子、並びに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 |
JP2012054135A (ja) * | 2010-09-02 | 2012-03-15 | Hitachi Maxell Energy Ltd | 電気化学素子用電極およびリチウムイオン二次電池 |
JP2012234766A (ja) * | 2011-05-09 | 2012-11-29 | Sony Corp | リチウムイオン二次電池用活物質、リチウムイオン二次電池用電極、リチウムイオン二次電池、電子機器、電動工具、電動車両および電力貯蔵システム |
JP2015018678A (ja) * | 2013-07-10 | 2015-01-29 | 株式会社田中化学研究所 | リチウム二次電池用正極活物質、正極および二次電池 |
JP2015041600A (ja) * | 2013-08-23 | 2015-03-02 | Agcセイミケミカル株式会社 | リチウムイオン二次電池用のリチウム含有複合酸化物の製造方法 |
Cited By (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10149425B2 (en) | 2013-10-15 | 2018-12-11 | Lemken Gmbh & Co. Kg. | Seed meter for a single-grain seeder |
US11011741B2 (en) | 2016-12-07 | 2021-05-18 | Sumitomo Chemical Company, Limited | Positive electrode active material for lithium secondary batteries, positive electrode for lithium secondary batteries, and lithium secondary battery |
EP3605672A4 (en) * | 2017-03-31 | 2021-02-17 | Sumitomo Chemical Company, Limited | POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, POSITIVE ELECTRODE FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY |
CN110462897B (zh) * | 2017-03-31 | 2022-08-09 | 住友化学株式会社 | 锂二次电池用正极活性物质、锂二次电池用正极以及锂二次电池 |
CN110462897A (zh) * | 2017-03-31 | 2019-11-15 | 住友化学株式会社 | 锂二次电池用正极活性物质、锂二次电池用正极以及锂二次电池 |
KR102566587B1 (ko) | 2017-05-31 | 2023-08-11 | 스미또모 가가꾸 가부시끼가이샤 | 리튬 이차 전지용 정극 활물질, 리튬 이차 전지용 정극 및 리튬 이차 전지 |
JP6368022B1 (ja) * | 2017-05-31 | 2018-08-01 | 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 |
CN110692154A (zh) * | 2017-05-31 | 2020-01-14 | 住友化学株式会社 | 锂二次电池用正极活性物质、锂二次电池用正极以及锂二次电池 |
KR20200014293A (ko) * | 2017-05-31 | 2020-02-10 | 스미또모 가가꾸 가부시끼가이샤 | 리튬 이차 전지용 정극 활물질, 리튬 이차 전지용 정극 및 리튬 이차 전지 |
JP2018206750A (ja) * | 2017-05-31 | 2018-12-27 | 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 |
CN110692154B (zh) * | 2017-05-31 | 2022-07-01 | 住友化学株式会社 | 锂二次电池用正极活性物质、锂二次电池用正极以及锂二次电池 |
US11283073B2 (en) | 2017-05-31 | 2022-03-22 | Sumitomo Chemical Company, Limited | Positive electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery |
WO2018221442A1 (ja) * | 2017-05-31 | 2018-12-06 | 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 |
JP2019040675A (ja) * | 2017-08-22 | 2019-03-14 | 住友金属鉱山株式会社 | 非水系二次電池用正極活物質の製造方法及び遷移金属化合物 |
JP7056035B2 (ja) | 2017-08-22 | 2022-04-19 | 住友金属鉱山株式会社 | 非水系二次電池用正極活物質の製造方法及び遷移金属化合物 |
WO2019098384A1 (ja) * | 2017-11-20 | 2019-05-23 | 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 |
EP3678235A4 (en) * | 2017-11-20 | 2021-06-02 | Sumitomo Chemical Company Limited | POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, POSITIVE ELECTRODE FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY |
US10923719B2 (en) | 2017-11-20 | 2021-02-16 | Sumitomo Chemical Company, Limited | Positive-electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery |
KR102161956B1 (ko) * | 2017-11-20 | 2020-10-06 | 스미또모 가가꾸 가부시끼가이샤 | 리튬 이차 전지용 정극 활물질, 리튬 이차 전지용 정극 및 리튬 이차 전지 |
KR20200027978A (ko) * | 2017-11-20 | 2020-03-13 | 스미또모 가가꾸 가부시끼가이샤 | 리튬 이차 전지용 정극 활물질, 리튬 이차 전지용 정극 및 리튬 이차 전지 |
JP2019096406A (ja) * | 2017-11-20 | 2019-06-20 | 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 |
WO2020110260A1 (ja) | 2018-11-29 | 2020-06-04 | 株式会社 東芝 | 電極、電池、及び電池パック |
Also Published As
Publication number | Publication date |
---|---|
EP3306713A1 (en) | 2018-04-11 |
JPWO2016195036A1 (ja) | 2018-03-29 |
KR102566584B1 (ko) | 2023-08-11 |
CN107615530B (zh) | 2020-12-11 |
EP3306713A4 (en) | 2019-01-16 |
KR20180014724A (ko) | 2018-02-09 |
US20180159127A1 (en) | 2018-06-07 |
CN107615530A (zh) | 2018-01-19 |
EP3306713B1 (en) | 2020-04-08 |
JP6768647B2 (ja) | 2020-10-14 |
US10756343B2 (en) | 2020-08-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5701343B2 (ja) | リチウム二次電池用正極活物質、正極および二次電池 | |
WO2016195036A1 (ja) | 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 | |
JP5287520B2 (ja) | 電極活物質、電極および非水電解質二次電池 | |
JP5292885B2 (ja) | 正極活物質粉末 | |
JP5644392B2 (ja) | 遷移金属複合水酸化物およびリチウム複合金属酸化物 | |
US8852805B2 (en) | Electrode active material comprising a mixture of a layered crystal structure material and a spinel crystal structure material, electrode, and non-aqueous electrolyte secondary battery | |
JP5842478B2 (ja) | リチウム複合金属酸化物およびその製造方法 | |
JP5504800B2 (ja) | リチウム複合金属酸化物および正極活物質 | |
WO2014007360A1 (ja) | リチウム複合金属酸化物、リチウム複合金属酸化物の製造方法、正極活物質、正極および非水電解質二次電池 | |
JP2009158484A (ja) | 非水電解液二次電池 | |
KR20120038983A (ko) | 분말 재료 및 정극 합제 | |
JP6068530B2 (ja) | リチウム二次電池用正極活物質、正極および二次電池 | |
WO2011040379A1 (ja) | リチウム複合金属酸化物および非水電解質二次電池 | |
WO2014007357A1 (ja) | リチウム複合金属酸化物、正極活物質、正極および非水電解質二次電池 | |
JP2011216472A (ja) | 正極用粉末 | |
JP5742193B2 (ja) | リチウム複合金属酸化物および非水電解質二次電池 | |
JP2010118161A (ja) | 非水電解質二次電池 | |
JP2011088812A (ja) | 遷移金属水酸化物の製造方法 |
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: 16803470 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017522257 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15577727 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20177035695 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2016803470 Country of ref document: EP |