WO2021235454A1 - Lithium composite oxide and production method therefor - Google Patents

Lithium composite oxide and production method therefor Download PDF

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WO2021235454A1
WO2021235454A1 PCT/JP2021/018864 JP2021018864W WO2021235454A1 WO 2021235454 A1 WO2021235454 A1 WO 2021235454A1 JP 2021018864 W JP2021018864 W JP 2021018864W WO 2021235454 A1 WO2021235454 A1 WO 2021235454A1
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composite oxide
lithium composite
lithium
metal
layered structure
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PCT/JP2021/018864
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French (fr)
Japanese (ja)
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直明 藪内
仁泰 金
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国立大学法人横浜国立大学
東ソー株式会社
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Priority claimed from JP2020142875A external-priority patent/JP2021183555A/en
Application filed by 国立大学法人横浜国立大学, 東ソー株式会社 filed Critical 国立大学法人横浜国立大学
Publication of WO2021235454A1 publication Critical patent/WO2021235454A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G45/00—Compounds of manganese
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G51/00—Compounds of cobalt
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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 lithium composite oxide and a method for producing the same, and more particularly to a lithium composite oxide in which a dissimilar metal having improved output characteristics is substituted and a method for producing the same.
  • a lithium composite oxide is generally used as the positive electrode active material for a lithium secondary battery.
  • Lithium composite oxides specifically lithium cobalt oxide (LiCoO 2 ), lithium nickel oxide (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), etc., are the positive electrodes of lithium secondary batteries distributed worldwide. It is often used as an active material. Active research is being conducted on improving the characteristics (high capacity, high output, cycle stabilization) and safety of such lithium composite oxides.
  • lithium as a positive electrode active material for a lithium secondary battery suitable for the target (Li), nickel (Ni), cobalt (Co), made of manganese (Mn) and oxygen (O) Li x Ni 1- y-z Co y Mn z O 2 (NCM), Li, Ni, Co, aluminum (Al) and consisting of O Li x Ni 1-y- z Co y Al z O 2 (NCA) is used.
  • NCM Li, Ni, Co, aluminum
  • NCA O Li x Ni 1-y- z Co y Al z O 2
  • These materials improve safety by reducing the amount of Co than the existing lithium composite oxide, using a less expensive metal, the discharge capacity NCM is 165 mAh / g approximately, LiCoO 2 with NCA is 200 mAh / g approximately A higher capacity has been achieved.
  • LiMnO 2 LiMnO 2
  • the crystal structure has a zigzag layered structure as a mother structure and has a domain of ⁇ -NaFeO type 2 layered structure.
  • Lithium composite oxide has been published as a high-capacity material (see Patent Document 1).
  • LiMnO 2 which is characterized by being composed of one or more of a rectangular crystal and a monoclinic crystal, has been published (see Patent Document 2 and Patent Document 3), and the discharge capacity is as low as about 170 mAh / g.
  • the crystal structure is modified by the step of heat treatment after mechanical milling, and the crystal structure is further improved as a positive electrode active material having a high discharge capacity of 260 mAh / g.
  • LiMnO 2 has found a positive electrode active material for a lithium secondary battery, which has a high capacity and is inexpensive, there is a problem that the output characteristics are low.
  • a metal composite oxide in which a dissimilar metal element is substituted with a manganese compound is produced, mixed with a lithium compound and sintered, and the crystal structure is changed from that of the existing LiMnO 2. It is a lithium composite oxide and a method for producing the same, which improves the output characteristics.
  • An object of the present invention is to solve the demand for high output, and to obtain a lithium composite oxide and a method for producing the same, in order to obtain a positive electrode active material for a lithium secondary battery having excellent electrochemical characteristics.
  • the present inventors have made intensive studies in order to solve the above problems, metal-substituted element LiMnO 2 of RenAkirakarada with crystals and monoclinic rectangular (in particular, Al, Co, Cr, Cu , Fe, Mg , Mo, Nb, Ni, Si, Ti, V, W, Zn, and an element selected from the group consisting of Zr) have been found to complete the present invention. That is, the gist of the present invention is as follows. [1] Composition formula Li x Me y Mn 1-y O 2 (However, 0 ⁇ x ⁇ 1.2 and 0 ⁇ y ⁇ 0.2.
  • Me is Al, Co, Cr, Cu, Fe, It is one or more metal elements selected from the group consisting of Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr), and has a rectangular zigzag layered structure as a matrix structure.
  • Metal elements selected from the group consisting of Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr
  • a lithium composite oxide characterized by having an intensity ratio (A / B) of 0.5 or more with the diffraction peak integrated intensity (B) observed at 2 ⁇ 1.0 °.
  • the positive electrode active material using the lithium composite oxide of the present invention has a remarkable effect that the discharge capacity can be improved and the output characteristics can be improved by having a structure in which dissimilar metals are substituted.
  • a positive electrode active material By applying such a positive electrode active material to a battery, it is expected to have an effect of providing a lithium secondary battery capable of holding down the price while having a high capacity and a high output.
  • the lithium composite oxide of the present invention is represented by the composition formula Li x Me y Mn 1-y O 2 (where 0 ⁇ x ⁇ 1.2 and 0 ⁇ y ⁇ 0.2), and is represented by manganese. Dissimilar metals have been replaced.
  • the dissimilar metal is one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr. It is preferably one or more metals selected from the group consisting of Al, Co, Fe, Mg, Nb, Ni, Ti, and Zn.
  • the amount of the dissimilar metal substituted is not particularly limited, but is preferably 20.0 mol% or less of manganese, and more preferably 1.0 to 10.0 mol%.
  • the lithium composite oxide of the present invention has an orthorhombic zigzag layered structure as a parent structure and has a domain of a monoclinic or rhombohedral ⁇ -NaFeO type 2 layered structure.
  • the mother structure is an orthorhombic zigzag layered structure, and the domain of monoclinic or rhombohedral ⁇ -NaFeO type 2 layered structure eliminates the need for an initial active charge / discharge cycle and develops high capacity from the initial cycle. Therefore, it is advantageous for the orthorhombic LiMnO 2 which is activated by charging and discharging for several tens of cycles to develop a high capacity.
  • the orthorhombic zigzag layered structure means that it belongs to the space group Pmnm.
  • a schematic diagram of the orthorhombic zigzag layered structure is shown in FIG.
  • schematic views of the layered structure and the rock salt type structure, which are different from the orthorhombic zigzag layered structure are shown in FIGS. 2 (2a) and 2 (2b), respectively.
  • the orthorhombic zigzag layered structure is a crystal structure in which the layers in the ⁇ -NaFeO type 2 layered structure are regularly grown up and down alternately to form a zigzag type layered structure. ..
  • the domain of the monoclinic or rhombohedral ⁇ -NaFeO type 2 layered structure means that it belongs to the space group C2 / m, R-3m or Fm-3m, and the monoclinic or rhombohedral ⁇ -NaFeO 2 Due to the domain of the type layered structure, the orthorhombic crystal and the monoclinic crystal or the rhombohedral crystal have a laminated crystal structure due to a stacking defect.
  • the lithium composite oxide of the present invention has a diffraction peak integrated intensity (A) observed at 15.3 ⁇ 1.0 ° and 18.2 ⁇ 1.0 ° by powder X-ray diffraction under the following measurement conditions. It is characterized in that the intensity ratio (A / B) with the observed diffraction peak integrated intensity (B) is 0.5 or more.
  • a / B intensity ratio with the observed diffraction peak integrated intensity
  • the main phase is a monoclinic or rhombohedral ⁇ -NaFeO type 2 layered structure, and a lithium composite oxide having a domain of an orthorhombic zigzag layered structure. Therefore, there is a possibility that cycle deterioration will increase.
  • the intensity ratio (A / B) is preferably 1.0 to 146.0, more preferably 2.6 to 33.6.
  • the BET specific surface area of the lithium composite oxide of the present invention is not particularly limited, but is preferably 8.0 m 2 / g or less, and more preferably 2.0 to 7.0 m 2 / g. As will be described later, the BET specific surface area is preferably 10.0 to 60.0 m 2 / g when the lithium composite oxide of the present invention is composited with a carbon or metal complexing agent. It is more preferably 0 to 40.0 m 2 / g. In this case, the BET specific surface area increases in proportion to the mixing ratio of the lithium composite oxide and the complexing agent and the specific surface area of the complexing agent.
  • Gas BET specific surface area of the lithium composite oxide converts an adsorption isotherm obtained from the physical gas adsorption on the BET plot, based on the BET isotherm determined gas adsorption amount V m of monolayer, which was used in physical adsorption It can be obtained by the so-called BET method, which calculates the specific surface area based on the molecular size of.
  • the particle size of the lithium composite oxide of the present invention is represented by the average particle size (D50) calculated from the particle size distribution by the laser diffraction / scattering method.
  • the average particle size (D50) of the lithium composite oxide of the present invention is not particularly limited, but is preferably 0.2 to 5.0 ⁇ m, more preferably 0.5 to 3.0 ⁇ m, and 0. 5 to 2.5 ⁇ m is more preferable.
  • the lithium composite oxide of the present invention is a composite lithium composite oxide in which a conductive carbon or metal is preferably composited on the surface thereof, thereby further improving electrochemical properties such as output characteristics. Can be done. Both carbon and metal may be used in combination.
  • the above-mentioned composite of the lithium composite oxide is carried out for the purpose of uniformly dispersing the active material and the composite agent containing carbon or metal in the electrode.
  • the lithium composite oxide of the active material has a wide range of secondary particles having an average particle size of 2.0 to 40.0 ⁇ m, so that an electrode having a non-uniform conduction path is formed.
  • the converted lithium composite oxide has the advantage that it can be uniformly mixed with these complexing agents together with the pulverization of secondary particles in the compounding process with carbon or metal, and a uniform electrode can be formed.
  • Examples of the carbon used to obtain the composite lithium composite oxide include carbon blacks such as graphene, carbon nanotubes, acetylene black, and Ketjen black, and acetylene black or Ketjen black is particularly preferable from the viewpoint of cost.
  • Examples of the metal include silver, copper, gold, aluminum, cobalt, zinc, and nickel, and aluminum, which is also used as a current collector for electrodes, is particularly preferable.
  • the lithium composite oxide of the present invention has a composition formula (Me y Mn 1-y ) a Ob (where 1.3 ⁇ a / b ⁇ 1.6, 0 ⁇ y ⁇ 0.2, and Me. Is represented by one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr).
  • a manganese compound having an average oxidation number of 2.6 or more and 3.3 or less and a lithium compound are mixed and sintered, and the main phase is lithium represented by Li x Me y Mn 1-y O 2 having a zigzag layered structure.
  • step of preparing a composite oxide can be the subjected to mechanical milling in Li x Me y Mn 1-y O 2 obtained in step, then be produced by heat treatment in an inert gas.
  • the raw materials for the metals used in manufacturing For example, sulfates, carbonates, nitrates, acetates, chlorides, hydroxides, oxides and the like are exemplified, but the present invention is not limited thereto.
  • the manganese compound has a composition formula (Me y Mn 1-y ) a Ob (where 1.3 ⁇ a / b ⁇ 1.6 and 0 ⁇ y ⁇ 0). .2, and Me is one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr).
  • Me is one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr).
  • an aqueous metal salt solution of a substituent and manganese is prepared in advance so that the average oxidation number of the metal ion is 2.6 or more and 3.3 or less and a preferable Me / Mn molar ratio is obtained.
  • Oxides [(Me ⁇ Mn) (OOH) c ], oxides [(Me ⁇ Mn) Od ] and the like are exemplified, but these are not limited.
  • a, b, c and d are numerical values satisfying the valence.
  • the raw material of the metal used in the production of the lithium composite oxide is not particularly limited, and examples thereof include sulfates, carbonates, nitrates, acetates, chlorides, hydroxides, and oxides. There is no limit.
  • the above manganese compound becomes a manganese oxide by sintering in air at 600 to 900 ° C. for 12 to 24 hours.
  • the average oxidation number of the metal ion of the manganese compound When the average oxidation number of the metal ion of the manganese compound is less than 2.6, it becomes Mn 3 O 4 attribution composition (Mn y Me 1-y ) 3 O 4 by sintering in air, and further 3. If more than 3 will MnO 2 belonging composition Mn y Me 1-y O 2 .
  • the main phase when sintered by mixing these manganese compound and the lithium compound is lithium composite oxide expressed by Li x Me y Mn 1-y O 2 having a zigzag layer structure is obtained, monoclinic or rhombic Since it does not have the domain of the hedron ⁇ -NaFeO type 2 layered structure, the improvement of the output characteristics is lost.
  • Preparing a metal salt aqueous solution of a substituent and manganese in advance so as to have a preferable Me / Mn molar ratio means producing a manganese compound at a Me / Mn molar ratio according to the charged composition.
  • the lithium compound to be mixed with the manganese compound is not particularly limited, and for example, lithium carbonate, lithium hydroxide, lithium nitrate, lithium acetate, lithium chloride, lithium iodide, lithium oxalate, etc.
  • examples thereof include lithium sulfate and lithium oxide, but these are not limited.
  • the sintering of the manganese compound and the lithium compound is not particularly limited, but is preferably carried out at 700 to 1000 ° C. for 6 to 24 hours in an inert gas, and mechanical milling is carried out, for example, from 300 to 300. It is preferably 6 to 72 hours at 800 rpm.
  • the above mechanical milling is preferably carried out in a closed container with a ball of the same material as the container in an inert gas.
  • the material of the closed container and the ball is not particularly limited, and examples thereof include silicon nitride, zirconia, stainless steel, tungsten carbide, sintered alumina, and the like, but there is no limitation thereof.
  • the heat treatment performed after the mechanical milling is not particularly limited, but is preferably performed at 500 to 900 ° C. for 1 to 24 hours, preferably in an inert gas, and is inert at 500 to 700 ° C. for 1 to 12 hours. It is more preferable to carry out in gas.
  • the lithium composite oxide of the present invention also has a metal composition of Me y Mn 1-y (where y is 0 ⁇ y ⁇ 0.2 and Me is Al, Co, Cr, Cu, Fe, Mg, Mo). , Nb, Ni, Si, Ti, V, W, Zn, and one or more metals selected from the group consisting of Zr), and the above lithium compound are mixed and hydrothermally treated in an alkaline aqueous solution. Can be manufactured in.
  • the term "in an alkaline aqueous solution” to which the above hydrothermal treatment is performed means, for example, a mixed solution of lithium hydroxide and potassium hydroxide.
  • the pH of the alkaline aqueous solution is preferably 11.0 to 13.5, for example.
  • the temperature of the above hydrothermal treatment is not particularly limited, but is preferably, for example, 150 ° C. or higher for 1 hour or longer, and 180 to 240 ° C. for 4 to 24 hours.
  • the above hydrothermal treatment does not particularly limit the mixing ratio (Li / Mn + Me) of the manganese compound and the lithium compound, but is preferably 1.5 or more, and more preferably 2.0 to 4.0.
  • the pH of the above hydrothermal treatment is not particularly limited, but is preferably 11 or more, and more preferably 12.0 to 13.5.
  • a preferable compounding means for producing the composite lithium composite oxide mechanical milling of carbon or metal having conductivity with the lithium composite oxide can be mentioned.
  • Mechanical milling is preferably performed in a closed container with a ball made of the same material as the container.
  • the material of the closed container and the ball is not particularly limited, but silicon nitride, zirconia, stainless steel, tungsten carbide, sintered alumina and the like are preferably exemplified, but the materials thereof are not limited thereto.
  • the above mechanical milling is carried out at high speed for a long time, and in addition to crushing the secondary particles of the active material, it has an orthorhombic zigzag layered structure as a mother structure, and is monoclinic or rhombic. Since the crystal structure having the domain of the ⁇ -NaFeO type 2 layered structure of the hedron may change to the rock salt type structure, it is preferable to carry out the process at a lower speed and in a shorter time than the conditions for producing the lithium composite oxide.
  • mechanical milling in order to more appropriately pulverize and composite the secondary particles of the active material, for example, it is preferably 1 to 24 hours at 100 to 600 rpm, and 2 to 12 hours at 100 to 300 rpm. More preferred.
  • the electrode (positive electrode) of the present invention is characterized by containing the lithium composite oxide of the present invention as a positive electrode active material, and preferably contains a conductive material and a binder in addition to the lithium composite oxide.
  • the conductive carbon or metal that is the composite agent in the composite lithium composite oxide can also function as a conductive material here, apart from the composite process.
  • a conductive polymer other than carbon or metal, which is a composite agent in the composite lithium composite oxide can also be used.
  • carbon or metal which is a composite agent in the composite lithium composite oxide can also be used.
  • the content of the conductive material with respect to the lithium composite oxide of the electrode (positive electrode) of the present invention is not particularly limited, but is preferably 1 to 10% by weight.
  • binder examples include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinyl chloride (PVC) carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and the like. Is exemplified, but there is no particular limitation.
  • the content of the binder in the electrode (positive electrode) of the present invention is not particularly limited, but is preferably 1 to 10% by weight, for example.
  • examples of the configuration of the lithium secondary battery other than the positive electrode include the following, but there is no particular limitation.
  • examples of the negative electrode include materials that reversibly occlude and release Li, such as carbon-based materials, tin oxide-based materials, silicon oxide-based materials, Li 4 Ti 5 O 12 , and materials that form alloys with Li.
  • Examples of the electrolyte include an organic electrolyte in which a Li salt and various additives are dissolved in an organic solvent, an ionic liquid, a Li ion conductive solid electrolyte, and a combination thereof.
  • the organic solvent of the electrolytic solution is not particularly limited, and examples thereof include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), and examples of the electrolyte salt include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC).
  • composition analysis> The composition of the prepared oxyhydroxide precursor and lithium composite oxide positive electrode active material was analyzed by ICP-AES (trade name: Optima5300DV, manufactured by PerkinElmer).
  • the BET specific surface area of the treated sample was measured by a one-point method using a BET measuring device (trade name: Micromeritics Flowsorb III, manufactured by Shimadzu Corporation) using nitrogen gas.
  • the average particle size (D50) was obtained from the particle size distribution map using a particle size distribution measuring device (trade name: MT3000II series, manufactured by MicrotracBEL). The measurement was carried out after adding an appropriate amount of the positive electrode active material to pure water and applying ultrasonic dispersion for 5 minutes.
  • ⁇ Making batteries> A weight ratio of the lithium composite oxide obtained in Examples and Comparative Examples, a conductive material (trade name: Denka Black, manufactured by Denka Co., Ltd.) and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) was 80:10 :. In No. 10, the mixture was mixed using an agate mortar, and further homogenized with a mixer (AR-100, manufactured by Thinky) to prepare a positive electrode material ink. The obtained positive electrode material ink was applied to aluminum foil to a thickness of 110 ⁇ m, dried at 80 ° C. for 2 hours, dried at 150 ° C.
  • the cut electrode was uniaxially pressed at 50 kN / cm 2 and dried under reduced pressure at 150 ° C. for 2 hours to obtain a positive electrode.
  • a solution in which EC and DMC are mixed at a volume ratio of 1: 2 as an electrolytic solution and a solution having a concentration of LiPF 6 at a concentration of 1.0 M is used as a separator, and Cellguard 2400 is used as a separator.
  • Cellguard 2400 is used as a separator.
  • (26 mm in diameter, manufactured by Celgard) was used as a negative electrode, and a lithium foil (18 mm in diameter, 200 ⁇ m in thickness, manufactured by Honjo Metal Co., Ltd.) was used.
  • ⁇ Charging / discharging cycle test> The performance of the prepared positive electrode and the battery was evaluated at 25 ° C. using a charge / discharge evaluation device (trade name: BTS2004W, manufactured by NAGANO). The measurement was performed by charging and discharging at a current density of 0.3 C in the potential range of 4.8 V to 1.5 V. For C-rate, 230 mAh / g was used as the practical discharge capacity, and 0.3 C was calculated (70 mA / g).
  • Example 1 Cobalt sulfate (CoSO 4 ) and manganese sulfate (MnSO 4 ) are dissolved in pure water to obtain an aqueous solution containing 0.025 mol / L (liter) cobalt sulfate and 1.975 mol / L manganese sulfate, which is used as a metal. It was made into a salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L. After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained.
  • the aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 8.5. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn and Co (theoretical composition (Co 0.025 Mn 0.975 ) 3 O 4 ). Obtained.
  • the manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Co 0.025 Mn 0.975 ) 2 O 3.
  • manganese oxide and commercially available lithium carbonate (Li 2 CO 3 , manufactured by Rare Metallic) were mixed in a mortar for 20 minutes so that the Li / (Co + Mn) molar ratio was 1.0. Dry mixing.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiCo 0.025 Mn 0.975 O 2 having a zigzag layered main phase was added. Obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • the obtained LiCo 0.025 Mn 0.975 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiCo 0.025 Mn 0.975 O 2.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiCo 0.025 Mn 0.975 O 2 having a rock salt type structure was heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and a domain of ⁇ -NaFeO type 2 layered structure.
  • a lithium composite oxide of LiCo 0.025 Mn 0.975 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 2 A lithium composite oxide was produced by the same method as in Example 1 except that an aqueous solution containing 0.05 mol / L cobalt sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. , Made a battery.
  • Example 3 A lithium composite oxide was produced by the same method as in Example 2 except that manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Co + Mn) molar ratio was 1.05. In addition, a battery was made.
  • Example 4 An aqueous solution containing 0.025 mol / L iron (III) sulfate (Fe 2 (SO 4 ) 3 ) and 1.975 mol / L manganese sulfate was used as a component of the metal salt aqueous solution.
  • the total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
  • the aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min.
  • the manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Fe 0.025 Mn 0.975 ) 2 O 3.
  • a theoretical composition Fe 0.025 Mn 0.975
  • manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Fe + Mn) molar ratio was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiFe 0.025 Mn 0.975 O 2 having a zigzag layered main phase was added. Obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • the obtained LiFe 0.025 Mn 0.975 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiFe 0.025 Mn 0.975 O 2.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiFe 0.025 Mn 0.975 O 2 having a rock salt type structure is heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and a domain of ⁇ -NaFeO type 2 layered structure.
  • a lithium composite oxide of LiFe 0.025 Mn 0.975 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 5 A lithium composite oxide was produced by the same method as in Example 4 except that an aqueous solution containing 0.05 mol / L iron (III) sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. Then, a battery was manufactured.
  • Example 6 An aqueous solution containing 0.025 mol / L nickel sulfate (NiSO 4 ), 0.025 mol / L titanyl sulfate (TIOSO 4 ) and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution.
  • the total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
  • 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained.
  • the aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min.
  • the manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Ni 0.025 Ti 0.025 Mn 0.95 ) 2 O 3.
  • a theoretical composition Ni 0.025 Ti 0.025 Mn 0.95
  • manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Ni + Ti + Mn) molar ratio was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and the main phase was LiNi 0.025 Ti 0.025 Mn 0. 95 O 2 was obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • LiNi 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain rock salt type LiNi 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and ⁇ -NaFeO type 2 type.
  • a lithium composite oxide of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 7 A lithium composite oxide was produced by the same method as in Example 6 except that manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Ni + Mn) molar ratio was 1.05. In addition, a battery was made.
  • Example 8 An aqueous solution containing 0.025 mol / L magnesium sulfate ( ⁇ 4 ), 0.025 mol / L titanyl sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L. After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min.
  • the manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Mg 0.025 Ti 0.025 Mn 0.95 ) 2 O 3.
  • a theoretical composition Mg 0.025 Ti 0.025 Mn 0.95
  • manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Mg + Ti + Mn) molar ratio was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and the main phase had a zigzag layered structure .
  • LiMg 0.025 Ti 0.025 Mn 0. 95 O 2 was obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • LiMg 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain rock salt type LiMg 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiMg 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and ⁇ -NaFeO type 2 type.
  • a lithium composite oxide of LiMg 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 9 LiMg 0.05 Ti 0.05 Mn in the same manner as in Example 8 except that an aqueous solution containing 0.05 mol / L magnesium sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. A 0.9 O 2 lithium composite oxide was produced, and a battery was further produced.
  • Example 10 An aqueous solution containing 0.025 mol / L zinc sulfate (ZnSO 4 ), 0.025 mol / L titanyl sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution.
  • the total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
  • the aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min.
  • the manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Zn 0.025 Ti 0.025 Mn 0.95 ) 2 O 3.
  • a theoretical composition Zn 0.025 Ti 0.025 Mn 0.95
  • manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Zn + Ti + Mn) molar ratio was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiZn 0.025 Ti 0.025 Mn 0.
  • the main phase had a zigzag layered structure.
  • 95 O 2 was obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • LiZn 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain rock salt type LiZn 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiZn 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and ⁇ -NaFeO type 2 type.
  • a lithium composite oxide of LiZn 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 11 An aqueous solution containing 0.05 mol / L magnesium sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution.
  • the total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
  • the aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min.
  • the manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Mg 0.05 Mn 0.95 ) 2 O 3.
  • a theoretical composition Mg 0.05 Mn 0.95 ) 2 O 3.
  • manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Mg + Mn) molar ratio was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiMg 0.05 Mn 0.95 O 2 having a zigzag layered main phase was added. Obtained.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • the obtained LiMg 0.05 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiMg 0.05 Mn 0.95 O 2.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiMg 0.05 Mn 0.95 O 2 having a rock salt type structure is heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and a domain of ⁇ -NaFeO type 2 layered structure.
  • a lithium composite oxide of LiMg 0.05 Mn 0.95 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Example 12 Manganese carbonate (MnCO 3 ) is calcined in air at 700 ° C. for 12 hours to prepare a manganese oxide having a theoretical composition (Mn 2 O 3).
  • Manganese oxide commercially available vanadium oxide (V) (V 2 O 5 , Wako) so that the V / (V + Mn) molar ratio of the metal composition is 0.05 and the Li / (V + Mn) molar ratio is 1.0.
  • V vanadium oxide
  • V vanadium oxide
  • Li / (V + Mn) molar ratio is 1.0.
  • commercially available lithium carbonate were dry-mixed in a dairy pot for 20 minutes. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiV 0.05 Mn 0.95 O 2 having a zigzag layered main phase was added. Obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C.
  • the obtained LiV 0.05 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain a rock salt type LiV 0.05 Mn 0.95 O 2.
  • a zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
  • LiV 0.05 Mn 0.95 O 2 having a rock salt type structure was heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and a domain of ⁇ -NaFeO type 2 layered structure.
  • a lithium composite oxide of LiV 0.05 Mn 0.95 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was produced according to the above ⁇ Production of Battery>.
  • Example 13 A lithium composite of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a zigzag layered structure as a mother structure and a domain of an ⁇ -NaFeO type 2 layered structure obtained in Example 6 in a closed container made of zirconia.
  • 0.4 g of oxide, 0.05 g of composite material (trade name: Denka Black, manufactured by Denka), 3 balls with a diameter of 10 mm, 10 balls with a diameter of 5 mm and 2 g of a ball with a diameter of 1 mm are put in and 12 at 100 rpm. Time mechanical milling was performed to obtain a carbon composite lithium composite oxide.
  • the obtained carbon composite lithium composite oxide and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) were uniformly mixed using a mixer at a weight ratio of 90:10 to obtain a positive electrode material ink.
  • a battery was manufactured according to the above ⁇ Battery preparation> except that the positive electrode material ink was used.
  • Example 14 A lithium composite of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a zigzag layered structure as a mother structure and a domain of an ⁇ -NaFeO type 2 layered structure obtained in Example 6 in a closed container made of zirconia. Mechanical milling was performed at 100 rpm for 12 hours with 0.4 g of oxide, 0.05 g of carbon nanotube (manufactured by Shenzhen SUSN Nanotech), 3 balls with a diameter of 10 mm, 10 balls with a diameter of 5 mm and 2 g of a ball with a diameter of 1 mm. A carbon composite lithium composite oxide was obtained.
  • the obtained carbon composite lithium composite oxide and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) were uniformly mixed using a mixer at a weight ratio of 90:10 to obtain a positive electrode material ink.
  • a battery was manufactured according to the above ⁇ Battery preparation> except that the positive electrode material ink was used.
  • Manganese carbonate (MnCO 3 ) was calcined in air at 700 ° C. for 12 hours to prepare a manganese oxide having a theoretical composition (Mn 2 O 3).
  • Manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / Mn molar ratio of the metal composition was 1.0.
  • the obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, and cooled to room temperature to obtain LiMnO 2 having a zigzag layered main phase.
  • the temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
  • the obtained LiMnO 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain a rock salt type LiMnO 2.
  • LiMnO 2 having a rock salt type structure is heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and lithium composite oxidation of LiMnO 2 having a domain of ⁇ -NaFeO type 2 layered structure. I got something. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above ⁇ Battery Fabrication>.
  • Comparative Example 2 A lithium composite oxide was produced in the same manner as in Comparative Example 1 except that LiMnO 2 having a rock salt structure was heat-treated at 700 ° C. for 12 hours in Ar gas, and a battery was further produced. Table 1 shows the production conditions and physical properties of Examples 1 to 14 and Comparative Examples 1 and 2.
  • ⁇ Average particle size of lithium composite oxide The particle size diameters of the lithium composite oxides produced in Examples 1 to 14 and Comparative Examples 1 and 2 were measured, and the average particle size (D50) of the results is shown in Table 1. It was confirmed that the lithium composite oxide produced in the examples did not change the particle size distribution composed of substitutions with different metals (Co, Fe, Ni + Ti, Mg + Ti, Zn + Ti, Mg, V).
  • the lithium composite oxide produced in the process of the present invention has a strong peak on the orthorhombic (010) plane, (011) plane, (200) plane, and (021) plane and a weak peak on the monoclinic (001) plane. It turned out to have. That is, it was found that the lithium composite oxide has an orthorhombic zigzag layered structure as a mother structure and has a domain of ⁇ -NaFeO type 2 layered structure. Furthermore, it was confirmed that the lithium composite oxide produced in the process of the present invention did not change the crystal structure composed of dissimilar metal substitutions.
  • Energy density (Wh / kg) discharge capacity (Ah / kg) x average discharge potential (V)
  • Energy density (Wh / L) Discharge capacity (Ah / kg) x Average discharge potential (V) x Electrode density (kg / L) The electrode density used in the above calculation is based on the weight of the positive electrode active material + conductive material + binder and the diameter and thickness of the electrodes, excluding the aluminum foil that is the current collector, from the electrodes manufactured according to the description of ⁇ Battery fabrication> above. It was calculated based on the obtained volume.
  • Example 13 From the discharge capacity results of 0.3C shown in Table 2, the improvement of the output characteristics of Examples 1 to 14 was shown from Comparative Examples 1 and 2 manufactured without metal element substitution. The same results were shown for the discharge capacities at 1.0C and 2.0C. The energy densities of the positive electrodes manufactured in Examples 1 to 14 shown in Table 2 also exceeded those of Comparative Examples 1 and 2, and a lithium secondary battery having a high capacity and a high output was achieved. In particular, in Examples 13 and 14, carbon was uniformly distributed around the lithium composite oxide, showing the effect of further improving the output characteristics. The SEM images of the lithium composite oxides of Examples 6 and 13 are shown in FIG. In Example 13, it was confirmed from the SEM image that the secondary particles of the active material had a more uniform particle size by pulverization by carbon-compositing the lithium composite oxide of Example 6.
  • the lithium composite oxide of the present invention is expected to be used in the field of positive electrode active materials for lithium secondary batteries as an inexpensive high-capacity, high-output positive electrode active material.

Abstract

Provided are: a lithium composite oxide having a restricted crystal structure and being for obtaining a positive electrode active material, which is for a lithium secondary battery and which has high capacity and high output characteristics; and a production method therefor.　Provided is a lithium composite oxide characterized by: being represented by the compositional formula LixMeyMn1-yO2 (where 0 < x ≤ 1.2 and 0 < y ≤ 0.2, and where Me is one or more metal element selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr); having an orthorhombic zigzag layered structure as a base structure; having a layered structure domain of a monoclinic or rhombohedral α-NaFeO2 type; having an intensity ratio (A/B) of at least 0.5 between a diffraction peak integrated intensity (A) observed by powder X-ray diffraction at 15.3±1.0° and a diffraction peak integrated intensity (B) observed at 18.2±1.0°; and preferably being composited by a carbon or metal compositing agent having conductivity.

Description

リチウム複合酸化物及びその製造方法Lithium composite oxide and its manufacturing method
　本発明は、リチウム複合酸化物及びその製造方法に関し、より詳しくは、出力特性を向上した異種金属を置換されたリチウム複合酸化物及びその製造方法に関する。 The present invention relates to a lithium composite oxide and a method for producing the same, and more particularly to a lithium composite oxide in which a dissimilar metal having improved output characteristics is substituted and a method for producing the same.
　リチウム二次電池用正極活物質は一般的にリチウム複合酸化物が使用されている。リチウム複合酸化物、具体的にはコバルト酸リチウム（ＬｉＣｏＯ２）、ニッケル酸リチウム（ＬｉＮｉＯ２）、マンガン酸リチウム（ＬｉＭｎ２Ｏ４）等、は全世界に流通されているリチウム二次電池の正極活物質として多く使用されている。このようなリチウム複合酸化物は特性改善（高容量化、高出力化、サイクル安定化）や安全性改善に活発な研究が行われている。 A lithium composite oxide is generally used as the positive electrode active material for a lithium secondary battery. Lithium composite oxides, specifically lithium cobalt oxide (LiCoO 2 ), lithium nickel oxide (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), etc., are the positive electrodes of lithium secondary batteries distributed worldwide. It is often used as an active material. Active research is being conducted on improving the characteristics (high capacity, high output, cycle stabilization) and safety of such lithium composite oxides.
　これらの目標に適するリチウム二次電池用正極活物質としてリチウム（Ｌｉ）、ニッケル（Ｎｉ）、コバルト（Ｃｏ）、マンガン（Ｍｎ）及び酸素（Ｏ）からなるＬｉｘＮｉ１－ｙ－ｚＣｏｙＭｎｚＯ２（ＮＣＭ）、Ｌｉ、Ｎｉ、Ｃｏ、アルミニウム（Ａｌ）及びＯからなるＬｉｘＮｉ１－ｙ－ｚＣｏｙＡｌｚＯ２（ＮＣＡ）が使用されている。これらの材料は既存リチウム複合酸化物よりＣｏの使用量を減らして安全性を高めて、より安価な金属を使用し、放電容量もＮＣＭが１６５ｍＡｈ／ｇ程度、ＮＣＡが２００ｍＡｈ／ｇ程度でＬｉＣｏＯ２より高容量を実現された。 These lithium as a positive electrode active material for a lithium secondary battery suitable for the target (Li), nickel (Ni), cobalt (Co), made of manganese (Mn) and oxygen (O) Li x Ni 1- y-z Co y Mn z O 2 (NCM), Li, Ni, Co, aluminum (Al) and consisting of O Li x Ni 1-y- z Co y Al z O 2 (NCA) is used. These materials improve safety by reducing the amount of Co than the existing lithium composite oxide, using a less expensive metal, the discharge capacity NCM is 165 mAh / g approximately, LiCoO 2 with NCA is 200 mAh / g approximately A higher capacity has been achieved.
　このようなリチウム二次電池の性能向上については特に高容量化が注目されており、ＬｉＭｎＯ２で表され、結晶構造がジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するリチウム複合酸化物が高容量材料として公開された（特許文献１参照）。 In particular, attention has been paid to increasing the capacity of such a lithium secondary battery, and it is represented by LiMnO 2 , and the crystal structure has a zigzag layered structure as a mother structure and has a domain of α-NaFeO type 2 layered structure. Lithium composite oxide has been published as a high-capacity material (see Patent Document 1).
　直方晶及び単斜晶のうちの１種以上からなることを特徴とするＬｉＭｎＯ２が公開され（特許文献２及び特許文献３参照）、放電容量は１７０ｍＡｈ／ｇ程度で低容量であったが、特許文献１では、メカニカルミリング後熱処理する工程により結晶構造が変型し、２６０ｍＡｈ／ｇである高い放電容量を持つ正極活物質としてさらに改良された。
　このようなＬｉＭｎＯ２は高容量でありながら安価であるリチウム二次電池用正極活物質を見出したが、出力特性が低い課題がある。 LiMnO 2, which is characterized by being composed of one or more of a rectangular crystal and a monoclinic crystal, has been published (see Patent Document 2 and Patent Document 3), and the discharge capacity is as low as about 170 mAh / g. In Patent Document 1, the crystal structure is modified by the step of heat treatment after mechanical milling, and the crystal structure is further improved as a positive electrode active material having a high discharge capacity of 260 mAh / g.
Although such LiMnO 2 has found a positive electrode active material for a lithium secondary battery, which has a high capacity and is inexpensive, there is a problem that the output characteristics are low.
　本発明は出力特性が低いとの課題に鑑みて、マンガン化合物に異種金属元素を置換された金属複合酸化物を製造し、リチウム化合物と混合して焼結し、既存ＬｉＭｎＯ２より結晶構造を変化させ、出力特性を改善するリチウム複合酸化物及びその製造方法である。 In view of the problem that the output characteristics of the present invention are low, a metal composite oxide in which a dissimilar metal element is substituted with a manganese compound is produced, mixed with a lithium compound and sintered, and the crystal structure is changed from that of the existing LiMnO 2. It is a lithium composite oxide and a method for producing the same, which improves the output characteristics.
特開２０１９－１５３５６４号公報Japanese Unexamined Patent Publication No. 2019-153564 特開２００３－００７２９７号公報Japanese Patent Application Laid-Open No. 2003-007297 特開２００２－１４５６１９号公報Japanese Unexamined Patent Publication No. 2002-145619
　リチウム二次電池は最近電子機器が小型、軽量化されるに伴って、ますます高容量、高電圧、高出力などの電気化学的特性に優れた電池を開発するための研究が進められている。特に、背景技術に記載されているようにリチウム二次電池用正極材の実用化に活物質の高出力化は必須で要求される。
　本発明は、高出力化の要求を解決することを目的とし、電気化学的特性に優れたリチウム二次電池用正極活物質を得るためのリチウム複合酸化物及びその製造方法にある。 With the recent miniaturization and weight reduction of electronic devices, lithium secondary batteries are being researched to develop batteries with excellent electrochemical characteristics such as higher capacity, higher voltage, and higher output. .. In particular, as described in the background art, high output of the active material is indispensable and required for practical use of the positive electrode material for lithium secondary batteries.
An object of the present invention is to solve the demand for high output, and to obtain a lithium composite oxide and a method for producing the same, in order to obtain a positive electrode active material for a lithium secondary battery having excellent electrochemical characteristics.
　本発明者らは、上記の課題を解決するために鋭意検討した結果、直方晶及び単斜晶を有する連晶体のＬｉＭｎＯ２に金属置換元素（特に、Ａｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選択される元素）を含むリチウム複合酸化物を見出して、本発明を完成させるに至った。
　すなわち、本発明の要旨は以下のとおりである。
［１］　組成式ＬｉｘＭｅｙＭｎ１－ｙＯ２（但し、０＜ｘ≦１．２であり、０＜ｙ≦０．２である。ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属元素である。）で示され、直方晶系ジグザグ層状構造を母構造とし、単斜晶又は菱面体晶α-ＮａＦｅＯ２型層状構造のドメインを有し、かつ、粉体Ｘ線回折で１５．３±１．０°に観測される回折ピーク積分強度（Ａ）と１８．２±１．０°に観測される回折ピーク積分強度（Ｂ）との強度比（Ａ／Ｂ）が０．５以上であることを特徴とするリチウム複合酸化物。
［２］　前記ＭｅがＡｌ、Ｃｏ、Ｆｅ、Ｍｇ、Ｎｂ、Ｎｉ、Ｔｉ、及びＺｎからなる群より選ばれる１種以上の金属元素である上記［１］に記載のリチウム複合酸化物。
［３］　ＢＥＴ比表面積が８．０ｍ２／ｇ以下であり、平均粒子径（Ｄ５０）が、０．２～５．０μｍである上記［１］又は［２］に記載のリチウム複合酸化物。
［４］　導電性を有するカーボン若しくは金属で複合化されている上記［１］～［３］のいずれかに記載のリチウム複合酸化物。
［５］　上記［１］～［４］のいずれかに記載のリチウム複合酸化物の製造方法であって、組成式（ＭｅｙＭｎ１－ｙ）ａＯｂ（但し、１．３＜ａ／ｂ＜１．６であり、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示され、金属イオンの平均酸化数が２．６以上３．３以下であるマンガン化合物とリチウム化合物を混合して焼結し、主相がジグザグ層状構造を有するＬｉｘＭｅｙＭｎ１－ｙＯ２で表されるリチウム複合酸化物を作製する工程、及び、前記工程で得られたＬｉｘＭｅｙＭｎ１－ｙＯ２にメカニカルミリングを施し、次いで不活性ガス中で熱処理することを特徴とする製造方法。
［６］　上記［１］～［４］のいずれかに記載のリチウム複合酸化物の製造方法であって、金属組成がＭｅｙＭｎ１－ｙ（但し、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示されるマンガン化合物とリチウム化合物を混合し、次いでアルカリ性水溶液中で水熱処理することを特徴とする製造方法。
［７］　得られるリチウム複合酸化物を、次いで、導電性を有するカーボン若しくは金属の複合化剤とともにメカニカルミリングする上記［５］又は［６］に記載の製造方法。
［８］　上記［１］～［４］のいずれかに記載のリチウム複合酸化物を含む電極。
［９］　上記［８］に記載の電極を正極に使用したリチウム二次電池。 The present inventors have made intensive studies in order to solve the above problems, metal-substituted element LiMnO 2 of RenAkirakarada with crystals and monoclinic rectangular (in particular, Al, Co, Cr, Cu , Fe, Mg , Mo, Nb, Ni, Si, Ti, V, W, Zn, and an element selected from the group consisting of Zr) have been found to complete the present invention.
That is, the gist of the present invention is as follows.
[1] Composition formula Li x Me y Mn 1-y O 2 (However, 0 <x ≦ 1.2 and 0 <y ≦ 0.2. Me is Al, Co, Cr, Cu, Fe, It is one or more metal elements selected from the group consisting of Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr), and has a rectangular zigzag layered structure as a matrix structure. , Monooblique crystal or rhombic crystal α-NaFeO type 2 layered structure domain, and diffraction peak integrated intensity (A) observed at 15.3 ± 1.0 ° by powder X-ray diffraction. A lithium composite oxide characterized by having an intensity ratio (A / B) of 0.5 or more with the diffraction peak integrated intensity (B) observed at 2 ± 1.0 °.
[2] The lithium composite oxide according to the above [1], wherein Me is one or more metal elements selected from the group consisting of Al, Co, Fe, Mg, Nb, Ni, Ti, and Zn.
[3] The lithium composite oxide according to the above [1] or [2], which has a BET specific surface area of 8.0 m 2 / g or less and an average particle size (D50) of 0.2 to 5.0 μm.
[4] The lithium composite oxide according to any one of the above [1] to [3], which is composited with conductive carbon or metal.
[5] The method for producing a lithium composite oxide according to any one of the above [1] to [4], wherein the composition formula (Me y Mn 1-y ) a Ob (where 1.3 <a / b <1.6, 0 <y ≦ 0.2, and Me is Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr. A manganese compound and a lithium compound, which are represented by one or more metals selected from the group consisting of two or more and have an average oxidation number of metal ions of 2.6 or more and 3.3 or less, are mixed and sintered, and the main phase is zigzag. step of preparing a lithium composite oxide represented by Li x Me y Mn 1-y O 2 having a layered structure, and is subjected to mechanical milling in Li x Me y Mn 1-y O 2 obtained in the step Then, a production method characterized by heat treatment in an inert gas.
[6] The method for producing a lithium composite oxide according to any one of the above [1] to [4], wherein the metal composition is Me y Mn 1-y (provided that 0 <y ≦ 0.2). Me is a manganese compound represented by (one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr). A production method characterized by mixing a lithium compound and then hydrothermally treating it in an alkaline aqueous solution.
[7] The production method according to the above [5] or [6], wherein the obtained lithium composite oxide is mechanically milled together with a conductive carbon or metal complexing agent.
[8] The electrode containing the lithium composite oxide according to any one of the above [1] to [4].
[9] A lithium secondary battery using the electrode according to the above [8] as a positive electrode.
　本発明のリチウム複合酸化物を用いた正極活物質は、異種金属が置換された構造を有することにより、放電容量が改善し、出力特性が向上することができるという顕著な効果を奏する。このような正極活物質を電池に適用することで、高容量及び高出力でありながら価格を抑えることが可能なリチウム二次電池を提供できる効果が期待される。 The positive electrode active material using the lithium composite oxide of the present invention has a remarkable effect that the discharge capacity can be improved and the output characteristics can be improved by having a structure in which dissimilar metals are substituted. By applying such a positive electrode active material to a battery, it is expected to have an effect of providing a lithium secondary battery capable of holding down the price while having a high capacity and a high output.
直方晶系ジグザグ層状構造を示した模式図である。It is a schematic diagram which showed the orthorhombic zigzag layer structure. 層状構造（２ａ）及び岩塩型構造（２ｂ）を示した模式図である。It is a schematic diagram which showed the layered structure (2a) and the rock salt type structure (2b). （３a）は実施例１～５及び比較例１、２のリチウム複合酸化物のＸＲＤパターンを、（３ｂ）は実施例６～１２のリチウム複合酸化物のＸＲＤパターンを、それぞれ示した図である。(3a) is a diagram showing the XRD pattern of the lithium composite oxides of Examples 1 to 5 and Comparative Examples 1 and 2, and (3b) is a diagram showing the XRD pattern of the lithium composite oxide of Examples 6 to 12, respectively. .. 実施例２、６及び比較例２のリチウム複合酸化物のＸＲＤパターンを示した図である。It is a figure which showed the XRD pattern of the lithium composite oxide of Examples 2 and 6 and Comparative Example 2. （５ａ）は実施例２、５、６及び比較例２における正極の０．３Ｃでの放電曲線を、（５ｂ）は実施例８、１０、１２及び比較例２における正極の０．３Ｃでの放電曲線を、それぞれ示した図である。(5a) is the discharge curve of the positive electrode in Examples 2, 5 and 6 and Comparative Example 2 at 0.3C, and (5b) is the discharge curve of the positive electrode in Examples 8, 10 and 12 and Comparative Example 2 at 0.3C. It is a figure which showed each discharge curve. 実施例６、１３の各リチウム複合酸化物のＳＥＭ像を示した図である。It is a figure which showed the SEM image of each lithium composite oxide of Examples 6 and 13.
　以下、本発明を詳細に説明する。
　本発明のリチウム複合酸化物は、組成式ＬｉｘＭｅｙＭｎ１－ｙＯ２（但し、０＜ｘ≦１．２であり、０＜ｙ≦０．２である）で示され、マンガンに異種金属が置換されている。 Hereinafter, the present invention will be described in detail.
The lithium composite oxide of the present invention is represented by the composition formula Li x Me y Mn 1-y O 2 (where 0 <x ≦ 1.2 and 0 <y ≦ 0.2), and is represented by manganese. Dissimilar metals have been replaced.
　異種金属は、Ａｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属であり、その内Ａｌ、Ｃｏ、Ｆｅ、Ｍｇ、Ｎｂ、Ｎｉ、Ｔｉ、及びＺｎからなる群より選ばれる１種以上の金属であることが好ましい。異種金属の置換量は、特に限定するものではないが、マンガンの２０．０モル％以下であることが好ましく、１.０～１０．０モル％であることがより好ましい。 The dissimilar metal is one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr. It is preferably one or more metals selected from the group consisting of Al, Co, Fe, Mg, Nb, Ni, Ti, and Zn. The amount of the dissimilar metal substituted is not particularly limited, but is preferably 20.0 mol% or less of manganese, and more preferably 1.0 to 10.0 mol%.
　本発明のリチウム複合酸化物は、直方晶系ジグザグ層状構造を母構造とし、単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造のドメインを有するものである。直方晶系ジグザグ層状構造を母構造とし、単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造のドメインを有することで、初期活性充放電サイクルが必要なく、初期サイクルから高容量を発現することが可能であるので、数十サイクル程度充放電を行うことで活性化して高容量を発現する直方晶ＬｉＭｎＯ２に対して有利である。 The lithium composite oxide of the present invention has an orthorhombic zigzag layered structure as a parent structure and has a domain of a monoclinic or rhombohedral α-NaFeO type 2 layered structure. The mother structure is an orthorhombic zigzag layered structure, and the domain of monoclinic or rhombohedral α-NaFeO type 2 layered structure eliminates the need for an initial active charge / discharge cycle and develops high capacity from the initial cycle. Therefore, it is advantageous for the orthorhombic LiMnO 2 which is activated by charging and discharging for several tens of cycles to develop a high capacity.
　ここに、直方晶系ジグザグ層状構造とは、空間群（Ｓｐａｃｅ　ｇｒｏｕｐ）Ｐｍｎｍに帰属することをいう。直方晶系ジグザグ層状構造の模式図を図１に示す。また、直方晶系ジグザグ層状構造とは異なる、層状構造及び岩塩型構造の模式図を、それぞれ、図２の（２ａ）、（２ｂ）に示す。図１及び図２からわかるように、直方晶系ジグザグ層状構造は、α－ＮａＦｅＯ２型層状構造における層が上下に交互に規則的に成長し、ジグザグ型の層状となっている結晶構造である。 Here, the orthorhombic zigzag layered structure means that it belongs to the space group Pmnm. A schematic diagram of the orthorhombic zigzag layered structure is shown in FIG. Further, schematic views of the layered structure and the rock salt type structure, which are different from the orthorhombic zigzag layered structure, are shown in FIGS. 2 (2a) and 2 (2b), respectively. As can be seen from FIGS. 1 and 2, the orthorhombic zigzag layered structure is a crystal structure in which the layers in the α-NaFeO type 2 layered structure are regularly grown up and down alternately to form a zigzag type layered structure. ..
　単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造のドメインとは、空間群Ｃ２／ｍ、Ｒ－３ｍ又はＦｍ－３ｍに帰属することをいい、単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造のドメインであることにより、直方晶と単斜晶又は菱面体晶が積層欠陥で連晶体構造になっているものである。 The domain of the monoclinic or rhombohedral α-NaFeO type 2 layered structure means that it belongs to the space group C2 / m, R-3m or Fm-3m, and the monoclinic or rhombohedral α-NaFeO 2 Due to the domain of the type layered structure, the orthorhombic crystal and the monoclinic crystal or the rhombohedral crystal have a laminated crystal structure due to a stacking defect.
　本発明のリチウム複合酸化物は、以下の測定条件での粉体Ｘ線回折で１５．３±１．０°に観測される回折ピーク積分強度（Ａ）と１８．２±１．０°に観測される回折ピーク積分強度（Ｂ）との強度比（Ａ／Ｂ）が０．５以上であることを特徴とするものである。
　［測定条件］
　　・Ｘ線源：ＣｕＫα線＝１．５４１８Å
　　・発散スリット：１／２°
　　・散乱スリット：１°
　　・受光スリット：２ｍｍ
　　・ステップ幅：０．０１°
　　・スキャンスピード：０．５°／ｍｉｎ The lithium composite oxide of the present invention has a diffraction peak integrated intensity (A) observed at 15.3 ± 1.0 ° and 18.2 ± 1.0 ° by powder X-ray diffraction under the following measurement conditions. It is characterized in that the intensity ratio (A / B) with the observed diffraction peak integrated intensity (B) is 0.5 or more.
[Measurement condition]
・ X-ray source: CuKα ray = 1.5418 Å
・ Divergence slit: 1/2 °
・ Scattering slit: 1 °
・ Light receiving slit: 2 mm
・ Step width: 0.01 °
・ Scan speed: 0.5 ° / min
　当該強度比（Ａ／Ｂ）が０．５未満であると、主相が単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造で、直方晶系ジグザグ層状構造のドメインを有するリチウム複合酸化物となり、サイクル劣化が大きくなる可能性がある。当該強度比（Ａ／Ｂ）は、１．０～１４６．０が好ましく、２．６～３３．６がより好ましい。 When the intensity ratio (A / B) is less than 0.5, the main phase is a monoclinic or rhombohedral α-NaFeO type 2 layered structure, and a lithium composite oxide having a domain of an orthorhombic zigzag layered structure. Therefore, there is a possibility that cycle deterioration will increase. The intensity ratio (A / B) is preferably 1.0 to 146.0, more preferably 2.6 to 33.6.
　本発明のリチウム複合酸化物のＢＥＴ比表面積は、特に限定するものではないが、８．０ｍ２／ｇ以下が好ましく、２．０～７．０ｍ２／ｇがより好ましい。なお、ＢＥＴ比表面積は、後記するように、本発明のリチウム複合酸化物がカーボン若しくは金属の複合化剤で複合化されている場合、１０．０～６０．０ｍ２／ｇが好ましく、１０．０～４０．０ｍ２／ｇがより好ましい。この場合、ＢＥＴ比表面積はリチウム複合酸化物と上記複合化剤との混合比や上記複合化剤の比表面積に比例して増加する。
　リチウム複合酸化物のＢＥＴ比表面積は、物理ガス吸着から求めた吸着等温線をＢＥＴプロットに変換し、ＢＥＴ等温式を基づいて単分子層のガス吸着量Ｖｍを求め、物理吸着に使用したガスの分子大きさを基に比表面積を計算する、いわゆるＢＥＴ法により求めることができる。 The BET specific surface area of the lithium composite oxide of the present invention is not particularly limited, but is preferably 8.0 m 2 / g or less, and more preferably 2.0 to 7.0 m 2 / g. As will be described later, the BET specific surface area is preferably 10.0 to 60.0 m 2 / g when the lithium composite oxide of the present invention is composited with a carbon or metal complexing agent. It is more preferably 0 to 40.0 m 2 / g. In this case, the BET specific surface area increases in proportion to the mixing ratio of the lithium composite oxide and the complexing agent and the specific surface area of the complexing agent.
Gas BET specific surface area of the lithium composite oxide converts an adsorption isotherm obtained from the physical gas adsorption on the BET plot, based on the BET isotherm determined gas adsorption amount V m of monolayer, which was used in physical adsorption It can be obtained by the so-called BET method, which calculates the specific surface area based on the molecular size of.
　本発明のリチウム複合酸化物の粒径は、レーザ回折・散乱法により粒度分布から算出される平均粒子径（Ｄ５０）によって表される。本発明のリチウム複合酸化物の平均粒子径（Ｄ５０）は、特に限定するものではないが、０．２～５．０μｍであることが好ましく、０．５～３．０μｍがより好ましく、０．５～２．５μｍがさらに好ましい。
　本発明のリチウム複合酸化物は、導電性を有するカーボン若しくは金属が好ましくはその表面に複合化されている複合化リチウム複合酸化物とすることにより、出力特性などの電気化学特性をさらに向上させることができる。カーボン、金属は、両者を併用してもよい。リチウム複合酸化物の上記複合化は活物質とカーボン若しくは金属を含む複合化剤が電極中に均一に分散することを目的として行う。活物質のリチウム複合酸化物は、二次粒子の平均粒子径が２．０～４０．０μｍの幅広い大きさを有するために伝導パスが不均一な電極が形成されることに対して、上記複合化したリチウム複合酸化物は、カーボン若しくは金属との複合化過程で二次粒子の粉砕と共にこれらの複合化剤との均一混合ができ、均一電極が形成できる利点がある。 The particle size of the lithium composite oxide of the present invention is represented by the average particle size (D50) calculated from the particle size distribution by the laser diffraction / scattering method. The average particle size (D50) of the lithium composite oxide of the present invention is not particularly limited, but is preferably 0.2 to 5.0 μm, more preferably 0.5 to 3.0 μm, and 0. 5 to 2.5 μm is more preferable.
The lithium composite oxide of the present invention is a composite lithium composite oxide in which a conductive carbon or metal is preferably composited on the surface thereof, thereby further improving electrochemical properties such as output characteristics. Can be done. Both carbon and metal may be used in combination. The above-mentioned composite of the lithium composite oxide is carried out for the purpose of uniformly dispersing the active material and the composite agent containing carbon or metal in the electrode. The lithium composite oxide of the active material has a wide range of secondary particles having an average particle size of 2.0 to 40.0 μm, so that an electrode having a non-uniform conduction path is formed. The converted lithium composite oxide has the advantage that it can be uniformly mixed with these complexing agents together with the pulverization of secondary particles in the compounding process with carbon or metal, and a uniform electrode can be formed.
　上記複合化リチウム複合酸化物を得るために使用されるカーボンとしては、グラフェン、カーボンナノチューブ、アセチレンブラック、ケッチェンブラックなどのカーボンブラックが挙げられ、特に、コスト面からアセチレンブラック又はケッチェンブラックが好ましい。また、上記金属とは、例えば、銀、銅、金、アルミニウム、コバルト、亜鉛、ニッケルが挙げられ、特に電極の集電体としても使用されるアルミニウムが好ましい。 Examples of the carbon used to obtain the composite lithium composite oxide include carbon blacks such as graphene, carbon nanotubes, acetylene black, and Ketjen black, and acetylene black or Ketjen black is particularly preferable from the viewpoint of cost. .. Examples of the metal include silver, copper, gold, aluminum, cobalt, zinc, and nickel, and aluminum, which is also used as a current collector for electrodes, is particularly preferable.
　本発明のリチウム複合酸化物は、組成式（ＭｅｙＭｎ１－ｙ）ａＯｂ（但し、１．３＜ａ／ｂ＜１．６であり、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示され、金属イオンの平均酸化数が２．６以上３．３以下であるマンガン化合物とリチウム化合物を混合して焼結し、主相がジグザグ層状構造を有するＬｉｘＭｅｙＭｎ１－ｙＯ２で表されるリチウム複合酸化物を作製する工程、及び、前記工程で得られたＬｉｘＭｅｙＭｎ１－ｙＯ２にメカニカルミリングを施し、次いで不活性ガス中で熱処理することで製造することができる。
　製造で使用する金属の原料に特に制限はない。例えば、硫酸塩、炭酸塩、硝酸塩、酢酸塩、塩化塩、水酸化塩、酸化塩等が例示されるが、これに制限はない。 The lithium composite oxide of the present invention has a composition formula (Me y Mn 1-y ) a Ob (where 1.3 <a / b <1.6, 0 <y ≦ 0.2, and Me. Is represented by one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr). A manganese compound having an average oxidation number of 2.6 or more and 3.3 or less and a lithium compound are mixed and sintered, and the main phase is lithium represented by Li x Me y Mn 1-y O 2 having a zigzag layered structure. step of preparing a composite oxide, and can be the subjected to mechanical milling in Li x Me y Mn 1-y O 2 obtained in step, then be produced by heat treatment in an inert gas.
There are no particular restrictions on the raw materials for the metals used in manufacturing. For example, sulfates, carbonates, nitrates, acetates, chlorides, hydroxides, oxides and the like are exemplified, but the present invention is not limited thereto.
　本発明のリチウム複合酸化物の製造において、マンガン化合物は、組成式（ＭｅｙＭｎ１－ｙ）ａＯｂ（但し、１．３＜ａ／ｂ＜１．６であり、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示され、金属イオンの平均酸化数が２．６以上３．３以下であり、好ましいＭｅ／Ｍｎモル比になるように置換元素とマンガンの金属塩水溶液を予め調製したものである。例えば、本発明において好ましいＭｅ／Ｍｎモル比に成るように予め調製した硫化物［（Ｍｅ・Ｍｎ）（ＳＯ４）ａ］、水酸化物［（Ｍｅ・Ｍｎ）（ＯＨ）ｂ］、オキシ水酸化物［（Ｍｅ・Ｍｎ）（ＯＯＨ）ｃ］、酸化物［（Ｍｅ・Ｍｎ）Ｏｄ］などが例示されるが、これらに制限はない。式中、ａ、ｂ、ｃ、ｄは原子価を満足する数値である。 In the production of the lithium composite oxide of the present invention, the manganese compound has a composition formula (Me y Mn 1-y ) a Ob (where 1.3 <a / b <1.6 and 0 <y ≦ 0). .2, and Me is one or more metals selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr). As shown, an aqueous metal salt solution of a substituent and manganese is prepared in advance so that the average oxidation number of the metal ion is 2.6 or more and 3.3 or less and a preferable Me / Mn molar ratio is obtained. For example, sulfides [(Me · Mn) (SO 4 ) a ], hydroxides [(Me · Mn) (OH) b ], and oxywater prepared in advance so as to have a preferable Me / Mn molar ratio in the present invention. Oxides [(Me · Mn) (OOH) c ], oxides [(Me · Mn) Od ] and the like are exemplified, but these are not limited. In the formula, a, b, c and d are numerical values satisfying the valence.
　リチウム複合酸化物の製造で使用される金属の原料に特に制限はなく、例えば、硫酸塩、炭酸塩、硝酸塩、酢酸塩、塩化塩、水酸化塩、酸化塩等が例示されるが、これらに制限はない。
　上記のマンガン化合物は、６００～９００℃で１２～２４時間、空気中で焼結することでマンガン酸化物になる。 The raw material of the metal used in the production of the lithium composite oxide is not particularly limited, and examples thereof include sulfates, carbonates, nitrates, acetates, chlorides, hydroxides, and oxides. There is no limit.
The above manganese compound becomes a manganese oxide by sintering in air at 600 to 900 ° C. for 12 to 24 hours.
　マンガン化合物の金属イオンの平均酸化数が２．６未満の場合は、空気中で焼結することでＭｎ３Ｏ４帰属組成（ＭｎｙＭｅ１－ｙ）３Ｏ４になり、さらに、３．３を超える場合は、ＭｎＯ２帰属組成ＭｎｙＭｅ１－ｙＯ２になる。これらのマンガン化合物とリチウム化合物を混合して焼結すると主相がジグザグ層状構造を有するＬｉｘＭｅｙＭｎ１－ｙＯ２で表されるリチウム複合酸化物は得られるものの、単斜晶又は菱面体晶α－ＮａＦｅＯ２型層状構造のドメインを有しないため、出力特性の改良性がなくなる。好ましいＭｅ／Ｍｎモル比になるように置換元素とマンガンの金属塩水溶液を予め調製するとは、仕込み組成通りのＭｅ／Ｍｎモル比でマンガン化合物を製造することをいう。 When the average oxidation number of the metal ion of the manganese compound is less than 2.6, it becomes Mn 3 O 4 attribution composition (Mn y Me 1-y ) 3 O 4 by sintering in air, and further 3. If more than 3 will MnO 2 belonging composition Mn y Me 1-y O 2 . Although the main phase when sintered by mixing these manganese compound and the lithium compound is lithium composite oxide expressed by Li x Me y Mn 1-y O 2 having a zigzag layer structure is obtained, monoclinic or rhombic Since it does not have the domain of the hedron α-NaFeO type 2 layered structure, the improvement of the output characteristics is lost. Preparing a metal salt aqueous solution of a substituent and manganese in advance so as to have a preferable Me / Mn molar ratio means producing a manganese compound at a Me / Mn molar ratio according to the charged composition.
　本発明のリチウム複合酸化物の製造において、マンガン化合物と混合するリチウム化合物は特に制限はないが、例えば、炭酸リチウム、水酸化リチウム、硝酸リチウム、酢酸リチウム、塩化リチウム、ヨウ化リチウム、蓚酸リチウム、硫酸リチウム、酸化リチウム等が例示されるが、これらに制限はない。
　上記のマンガン化合物とリチウム化合物の焼結は、特に限定するものではないが、例えば、７００～１０００℃で６～２４時間、不活性ガス中で行うことが好ましく、メカニカルミリングは、例えば、３００～８００ｒｐｍで６～７２時間とすることが好ましい。 In the production of the lithium composite oxide of the present invention, the lithium compound to be mixed with the manganese compound is not particularly limited, and for example, lithium carbonate, lithium hydroxide, lithium nitrate, lithium acetate, lithium chloride, lithium iodide, lithium oxalate, etc. Examples thereof include lithium sulfate and lithium oxide, but these are not limited.
The sintering of the manganese compound and the lithium compound is not particularly limited, but is preferably carried out at 700 to 1000 ° C. for 6 to 24 hours in an inert gas, and mechanical milling is carried out, for example, from 300 to 300. It is preferably 6 to 72 hours at 800 rpm.
　上記のメカニカルミリングは、密閉容器に入れ、容器と同じ材質のボールで不活性ガス中で行うことが好ましい。密閉容器とボールの材質は特に限定するものではないが、例えば、窒化ケイ素、ジルコニア、ステンレス、タングステンカーバイド、シンタードアルミナ等が例示されるが、これらに制限はない。 The above mechanical milling is preferably carried out in a closed container with a ball of the same material as the container in an inert gas. The material of the closed container and the ball is not particularly limited, and examples thereof include silicon nitride, zirconia, stainless steel, tungsten carbide, sintered alumina, and the like, but there is no limitation thereof.
　メカニカルミリングに次いで行う熱処理は、特に限定するものではないが、例えば、５００～９００℃で１～２４時間、不活性ガス中で行うことが好ましく、５００～７００℃で１～１２時間、不活性ガス中で行うことがより好ましい。 The heat treatment performed after the mechanical milling is not particularly limited, but is preferably performed at 500 to 900 ° C. for 1 to 24 hours, preferably in an inert gas, and is inert at 500 to 700 ° C. for 1 to 12 hours. It is more preferable to carry out in gas.
　本発明のリチウム複合酸化物は、また、金属組成がＭｅｙＭｎ１－ｙ（但し、ｙは０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示されるマンガン化合物と上記リチウム化合物を混合し、アルカリ性水溶液中で水熱処理することで製造することができる。 The lithium composite oxide of the present invention also has a metal composition of Me y Mn 1-y (where y is 0 <y ≦ 0.2 and Me is Al, Co, Cr, Cu, Fe, Mg, Mo). , Nb, Ni, Si, Ti, V, W, Zn, and one or more metals selected from the group consisting of Zr), and the above lithium compound are mixed and hydrothermally treated in an alkaline aqueous solution. Can be manufactured in.
　上記の水熱処理が行われるアルカリ性水溶液中とは、例えば、水酸化リチウム、水酸化カリウムの混合液をいう。アルカリ性水溶液のｐＨは、例えば、１１．０～１３．５とすることが好ましい。
　上記の水熱処理の温度は、特に限定するものではないが、例えば、１５０℃以上で１時間以上が好ましく、１８０～２４０℃で４～２４時間がより好ましい。
　上記の水熱処理は、マンガン化合物とリチウム化合物の混合比（Ｌｉ／Ｍｎ＋Ｍｅ）を特に限定するものではないが、１．５以上が好ましく、２．０～４．０がより好ましい。
　上記の水熱処理は、ｐＨを特に限定するものではないが、１１以上が好ましく、１２．０～１３．５がより好ましい。 The term "in an alkaline aqueous solution" to which the above hydrothermal treatment is performed means, for example, a mixed solution of lithium hydroxide and potassium hydroxide. The pH of the alkaline aqueous solution is preferably 11.0 to 13.5, for example.
The temperature of the above hydrothermal treatment is not particularly limited, but is preferably, for example, 150 ° C. or higher for 1 hour or longer, and 180 to 240 ° C. for 4 to 24 hours.
The above hydrothermal treatment does not particularly limit the mixing ratio (Li / Mn + Me) of the manganese compound and the lithium compound, but is preferably 1.5 or more, and more preferably 2.0 to 4.0.
The pH of the above hydrothermal treatment is not particularly limited, but is preferably 11 or more, and more preferably 12.0 to 13.5.
　本発明において、上記複合化リチウム複合酸化物を製造するための好ましい複合化手段としては、リチウム複合酸化物と導電性を有するカーボン若しくは金属をメカニカルミリングすることが挙げられる。メカニカルミリングは、密閉容器に入れ、容器と同じ材質のボールで行うことが好ましい。密閉容器とボールの材質は特に限定するものではないが、好ましくは、窒化ケイ素、ジルコニア、ステンレス、タングステンカーバイド、シンタードアルミナ等が例示されるが、これらに制限はない。 In the present invention, as a preferable compounding means for producing the composite lithium composite oxide, mechanical milling of carbon or metal having conductivity with the lithium composite oxide can be mentioned. Mechanical milling is preferably performed in a closed container with a ball made of the same material as the container. The material of the closed container and the ball is not particularly limited, but silicon nitride, zirconia, stainless steel, tungsten carbide, sintered alumina and the like are preferably exemplified, but the materials thereof are not limited thereto.
　複合化リチウム複合酸化物を製造するため、上記メカニカルミリングは、高速回転で長時間行うと、活物質の二次粒子の粉砕以外に直方晶系ジグザグ層状構造を母構造とし、単斜晶又は菱面体晶のα－ＮａＦｅＯ２型層状構造のドメインを有する結晶構造から岩塩型構造へ変化する可能性があるので、リチウム複合酸化物を製造する条件より低速、かつ、短時間で行うのが好ましい。メカニカルミリングは、活物質の二次粒子の粉砕や複合化をより適切に行うため、例えば、１００～６００ｒｐｍで１～２４時間とすることが好ましく、１００～３００ｒｐｍで２～１２時間とすることがより好ましい。 In order to produce a composite lithium composite oxide, the above mechanical milling is carried out at high speed for a long time, and in addition to crushing the secondary particles of the active material, it has an orthorhombic zigzag layered structure as a mother structure, and is monoclinic or rhombic. Since the crystal structure having the domain of the α-NaFeO type 2 layered structure of the hedron may change to the rock salt type structure, it is preferable to carry out the process at a lower speed and in a shorter time than the conditions for producing the lithium composite oxide. In mechanical milling, in order to more appropriately pulverize and composite the secondary particles of the active material, for example, it is preferably 1 to 24 hours at 100 to 600 rpm, and 2 to 12 hours at 100 to 300 rpm. More preferred.
　本発明の電極（正極）は、本発明のリチウム複合酸化物を正極活物質として含むことを特徴とし、当該リチウム複合酸化物のほかに、さらに、導電材及びバインダを含むことが好ましい。
　なお、上記複合化リチウム複合酸化物における複合化剤である導電性を有するカーボン若しくは金属は、上記複合化過程を別にして、ここにおける導電材としても機能することができる。ここにおける導電材としては、上記複合化リチウム複合酸化物における複合化剤であるカーボン若しくは金属以外の導電性高分子なども使用できる。もちろん、上記複合化リチウム複合酸化物における複合化剤であるカーボン若しくは金属も使用できる。
　本発明の電極（正極）のリチウム複合酸化物に対する導電材の含有量は、特に限定するものではないが、１～１０重量％であることが好ましい。 The electrode (positive electrode) of the present invention is characterized by containing the lithium composite oxide of the present invention as a positive electrode active material, and preferably contains a conductive material and a binder in addition to the lithium composite oxide.
The conductive carbon or metal that is the composite agent in the composite lithium composite oxide can also function as a conductive material here, apart from the composite process. As the conductive material here, a conductive polymer other than carbon or metal, which is a composite agent in the composite lithium composite oxide, can also be used. Of course, carbon or metal which is a composite agent in the composite lithium composite oxide can also be used.
The content of the conductive material with respect to the lithium composite oxide of the electrode (positive electrode) of the present invention is not particularly limited, but is preferably 1 to 10% by weight.
　上記のバインダとしては、例えば、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニル（ＰＶＦ）、ポリ塩化ビニル（ＰＶＣ）カルボキシメチルセルロース（ＣＭＣ）、スチレン・ブタジエンゴム（ＳＢＲ）等が例示されるが、特に制限はない。
　本発明の電極（正極）におけるバインダの含有量は、特に限定するものではないが、例えば、１～１０重量％であることが好ましい。 Examples of the binder include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinyl chloride (PVC) carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and the like. Is exemplified, but there is no particular limitation.
The content of the binder in the electrode (positive electrode) of the present invention is not particularly limited, but is preferably 1 to 10% by weight, for example.
　本発明において、正極以外のリチウム二次電池の構成としては、次のようなものを挙げることができるが、特に制限はない。
　負極には、Ｌｉを可逆に吸蔵放出する材料、例えば、炭素系材料、酸化錫系材料、酸化ケイ素系材料、Ｌｉ４Ｔｉ５Ｏ１２、Ｌｉと合金を形成する材料などが例示される。 In the present invention, examples of the configuration of the lithium secondary battery other than the positive electrode include the following, but there is no particular limitation.
Examples of the negative electrode include materials that reversibly occlude and release Li, such as carbon-based materials, tin oxide-based materials, silicon oxide-based materials, Li 4 Ti 5 O 12 , and materials that form alloys with Li.
　電解質には、例えば、有機溶媒にＬｉ塩や各種添加剤を溶解した有機電解液や、イオン液体、Ｌｉイオン伝導性の固体電解質、これらを組み合わせたものなどが例示される。当該電解液の有機溶媒としては、特に限定するものではないが、例えば、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）が例示され、電解質塩としては、テトラフルオロボレート（ＢＦ４ －）、ヘキサフルオロホスファート（ＰＦ６ －）、フルオロメタンスルホニルイミド（ＦＳＩ－）、トリフルオロメタンスルホニルイミド（ＴＦＳＩ－）、トリフルオロメタンスルホナート（ＣＦ３ＳＯ３ －）等が例示されるが、特に制限はない。 Examples of the electrolyte include an organic electrolyte in which a Li salt and various additives are dissolved in an organic solvent, an ionic liquid, a Li ion conductive solid electrolyte, and a combination thereof. The organic solvent of the electrolytic solution is not particularly limited, and examples thereof include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), and examples of the electrolyte salt include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). , tetrafluoroborate (BF 4 -), hexafluorophosphate (PF 6 -), trifluoromethane sulfonyl imide (FSI -), trifluoromethanesulfonyl imide (TFSI -), trifluoromethanesulfonate (CF 3 SO 3 -), etc. Is exemplified, but there is no particular limitation.
　以下に、本発明の実施例を挙げてより詳細に説明するが、本発明はこれらの実施例によりなんら限定されて解釈されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples of the present invention, but the present invention is not construed as being limited by these examples.
＜結晶構造の確認＞
　リチウム複合酸化物の結晶構造の同定について粉末ＸＲＤ（商品名：ＵｌｔｉｍａＩＶ、Ｒｉｇａｋｕ社製）を用いて行った。
　計測条件は以下の通りとした。
　・ターゲット：Ｃｕ／Ｋα
　・出力：８．０ｋＷ（２００ｍＡ－４０ｋＶ）
　・データ間隔：０．０１°又は０．０４°（２θ／θ）
　・測定範囲：１０～２０°（１．０°／ｍｉｎ）又は１０～９０°（５°／ｍｉｎ） <Confirmation of crystal structure>
The crystal structure of the lithium composite oxide was identified using powder XRD (trade name: UltimaIV, manufactured by Rigaku).
The measurement conditions were as follows.
・ Target: Cu / Kα
-Output: 8.0 kW (200 mA-40 kV)
-Data interval: 0.01 ° or 0.04 ° (2θ / θ)
-Measurement range: 10 to 20 ° (1.0 ° / min) or 10 to 90 ° (5 ° / min)
＜組成分析＞
　調製したオキシ水酸化物前駆体及びリチウム複合酸化物正極活物質の組成は、ＩＣＰ－ＡＥＳ（商品名：Ｏｐｔｉｍａ５３００ＤＶ、ＰｅｒｋｉｎＥｌｍｅｒ社製）で分析した。 <Composition analysis>
The composition of the prepared oxyhydroxide precursor and lithium composite oxide positive electrode active material was analyzed by ICP-AES (trade name: Optima5300DV, manufactured by PerkinElmer).
＜ＢＥＴ比表面積の測定＞
　試料１ｇをＢＥＴ比表面積測定用のガラス製セルに入れ、窒素気流下で１５０℃、１時間脱水処理を行い、粉体粒子に付着した水分の除去を行った。処理後の試料をＢＥＴ測定装置（商品名：Ｍｉｃｒｏｍｅｒｉｔｉｃｓ　ＦｌｏｗｓｏｒｂＩＩＩ、島津製作所社製）で窒素ガスを用いて１点法でＢＥＴ比表面積を測定した。 <Measurement of BET specific surface area>
1 g of the sample was placed in a glass cell for measuring the BET specific surface area and dehydrated at 150 ° C. for 1 hour under a nitrogen stream to remove water adhering to the powder particles. The BET specific surface area of the treated sample was measured by a one-point method using a BET measuring device (trade name: Micromeritics Flowsorb III, manufactured by Shimadzu Corporation) using nitrogen gas.
＜平均粒子径（Ｄ５０）の測定＞
　粒度分布測定装置（商品名：ＭＴ３０００ＩＩシリーズ、ＭｉｃｒｏｔｒａｃＢＥＬ社製）を使用して、粒子径分布図から平均粒子径（Ｄ５０）を求めた。測定は、純水に適量の正極活物質を入れて、５分間超音波分散をかけた後に行った。 <Measurement of average particle size (D50)>
The average particle size (D50) was obtained from the particle size distribution map using a particle size distribution measuring device (trade name: MT3000II series, manufactured by MicrotracBEL). The measurement was carried out after adding an appropriate amount of the positive electrode active material to pure water and applying ultrasonic dispersion for 5 minutes.
＜電池の作製＞
　実施例、比較例で得られたリチウム複合酸化物と導電材（商品名：デンカブラック、デンカ社製）とバインダ（１０ｗｔ％ＰｖｄＦ／Ｎ－Ｍｅｔｈｙｌ－２－Ｐｙｒｒｏｌｉｄｏｎｅ溶液）を重量比８０：１０：１０でメノウ乳鉢を使用して混合し、さらに混合器（ＡＲ－１００、Ｔｈｉｎｋｙ社製）で均一化して、正極材インクを作製した。得られた正極材インクはアルミニウムホイルに１１０μｍの厚さで塗布し、８０℃で２時間乾燥及び１５０℃で１２時間以上減圧乾燥後、直径１６ｍｍの円形に切った。切った電極は５０ｋＮ／ｃｍ２で一軸プレスし、１５０℃で２時間減圧乾燥して正極とした。 <Making batteries>
A weight ratio of the lithium composite oxide obtained in Examples and Comparative Examples, a conductive material (trade name: Denka Black, manufactured by Denka Co., Ltd.) and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) was 80:10 :. In No. 10, the mixture was mixed using an agate mortar, and further homogenized with a mixer (AR-100, manufactured by Thinky) to prepare a positive electrode material ink. The obtained positive electrode material ink was applied to aluminum foil to a thickness of 110 μm, dried at 80 ° C. for 2 hours, dried at 150 ° C. for 12 hours or more under reduced pressure, and then cut into a circle having a diameter of 16 mm. The cut electrode was uniaxially pressed at 50 kN / cm 2 and dried under reduced pressure at 150 ° C. for 2 hours to obtain a positive electrode.
　上記の正極以外のリチウム二次電池の構成には、電解液としてＥＣとＤＭＣを１：２の容積比で混合した溶液中にＬｉＰＦ６を１．０Ｍの濃度となる溶液を、セパレータとしてセルガード２４００（直径２６ｍｍ、セルガード社製）を、負極としてリチウム箔（直径１８ｍｍ、厚さ２００μｍ、本城金属社製）を用いた。 For the configuration of the lithium secondary battery other than the positive electrode described above, a solution in which EC and DMC are mixed at a volume ratio of 1: 2 as an electrolytic solution and a solution having a concentration of LiPF 6 at a concentration of 1.0 M is used as a separator, and Cellguard 2400 is used as a separator. (26 mm in diameter, manufactured by Celgard) was used as a negative electrode, and a lithium foil (18 mm in diameter, 200 μm in thickness, manufactured by Honjo Metal Co., Ltd.) was used.
＜充電・放電サイクル試験＞
　作製した正極及び電池の性能評価は充放電評価装置（商品名：ＢＴＳ２００４Ｗ、ＮＡＧＡＮＯ社製）を用いて２５℃で行った。測定は４．８Ｖ－１．５Ｖ電位範囲で０．３Ｃの電流密度で充放電を行った。Ｃ－ｒａｔｅは２３０ｍＡｈ／ｇを実用放電容量とし、０．３Ｃを算出した（７０ｍＡ／ｇ）。 <Charging / discharging cycle test>
The performance of the prepared positive electrode and the battery was evaluated at 25 ° C. using a charge / discharge evaluation device (trade name: BTS2004W, manufactured by NAGANO). The measurement was performed by charging and discharging at a current density of 0.3 C in the potential range of 4.8 V to 1.5 V. For C-rate, 230 mAh / g was used as the practical discharge capacity, and 0.3 C was calculated (70 mA / g).
　実施例１
　硫酸コバルト（ＣｏＳＯ４）及び硫酸マンガン（ＭｎＳＯ４）を純水に溶解し、０．０２５ｍｏｌ／Ｌ（リットル）の硫酸コバルト及び１．９７５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を得て、これを金属塩水溶液とした。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ８．５となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、ＭｎとＣｏを含むマンガン酸化物（理論組成（Ｃｏ０．０２５Ｍｎ０．９７５）３Ｏ４）を得た。 Example 1
Cobalt sulfate (CoSO 4 ) and manganese sulfate (MnSO 4 ) are dissolved in pure water to obtain an aqueous solution containing 0.025 mol / L (liter) cobalt sulfate and 1.975 mol / L manganese sulfate, which is used as a metal. It was made into a salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 8.5. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn and Co (theoretical composition (Co 0.025 Mn 0.975 ) 3 O 4 ). Obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｃｏ０．０２５Ｍｎ０．９７５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｃｏ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウム（Ｌｉ２ＣＯ３、レアメタリック社製）を乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＣｏ０．０２５Ｍｎ０．９７５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Co 0.025 Mn 0.975 ) 2 O 3. From the weight ratio of the metal composition obtained from the ICP, manganese oxide and commercially available lithium carbonate (Li 2 CO 3 , manufactured by Rare Metallic) were mixed in a mortar for 20 minutes so that the Li / (Co + Mn) molar ratio was 1.0. Dry mixing. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiCo 0.025 Mn 0.975 O 2 having a zigzag layered main phase was added. Obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＣｏ０．０２５Ｍｎ０．９７５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＣｏ０．０２５Ｍｎ０．９７５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiCo 0.025 Mn 0.975 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiCo 0.025 Mn 0.975 O 2. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＣｏ０．０２５Ｍｎ０．９７５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＣｏ０．０２５Ｍｎ０．９７５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiCo 0.025 Mn 0.975 O 2 having a rock salt type structure was heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and a domain of α-NaFeO type 2 layered structure. A lithium composite oxide of LiCo 0.025 Mn 0.975 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例２
　金属塩水溶液の成分が、０．０５ｍｏｌ／Ｌの硫酸コバルト及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いたこと以外は実施例１と同様の方法でリチウム複合酸化物を製造し、さらに、電池を作製した。 Example 2
A lithium composite oxide was produced by the same method as in Example 1 except that an aqueous solution containing 0.05 mol / L cobalt sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. , Made a battery.
　実施例３
　Ｌｉ／（Ｃｏ＋Ｍｎ）モル比が１．０５になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合したこと以外は実施例２と同様の方法でリチウム複合酸化物を製造し、さらに、電池を作製した。 Example 3
A lithium composite oxide was produced by the same method as in Example 2 except that manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Co + Mn) molar ratio was 1.05. In addition, a battery was made.
　実施例４
　金属塩水溶液の成分が、０．０２５ｍｏｌ／Ｌの硫酸鉄（ＩＩＩ）（Ｆｅ２（ＳＯ４）３）及び１．９７５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いた。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ８．５となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、ＭｎとＦｅを含むマンガン酸化物（理論組成（Ｆｅ０．０２５Ｍｎ０．９７５）３Ｏ４）を得た。 Example 4
An aqueous solution containing 0.025 mol / L iron (III) sulfate (Fe 2 (SO 4 ) 3 ) and 1.975 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 8.5. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn and Fe (theoretical composition (Fe 0.025 Mn 0.975 ) 3 O 4 ). Obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｆｅ０．０２５Ｍｎ０．９７５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｆｅ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＦｅ０．０２５Ｍｎ０．９７５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Fe 0.025 Mn 0.975 ) 2 O 3. From the weight ratio of the metal composition obtained from ICP, manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Fe + Mn) molar ratio was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiFe 0.025 Mn 0.975 O 2 having a zigzag layered main phase was added. Obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＦｅ０．０２５Ｍｎ０．９７５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＦｅ０．０２５Ｍｎ０．９７５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiFe 0.025 Mn 0.975 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiFe 0.025 Mn 0.975 O 2. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＦｅ０．０２５Ｍｎ０．９７５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＦｅ０．０２５Ｍｎ０．９７５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiFe 0.025 Mn 0.975 O 2 having a rock salt type structure is heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and a domain of α-NaFeO type 2 layered structure. A lithium composite oxide of LiFe 0.025 Mn 0.975 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例５
　金属塩水溶液の成分が、０．０５ｍｏｌ／Ｌの硫酸鉄（ＩＩＩ）及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いたこと以外は実施例４と同様の方法でリチウム複合酸化物を製造し、さらに、電池を作製した。 Example 5
A lithium composite oxide was produced by the same method as in Example 4 except that an aqueous solution containing 0.05 mol / L iron (III) sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. Then, a battery was manufactured.
　実施例６
　金属塩水溶液の成分が、０．０２５ｍｏｌ／Ｌの硫酸ニッケル（ＮｉＳＯ４）、０．０２５ｍｏｌ／Ｌの硫酸チタニル（ＴｉＯＳＯ４）及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いた。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ８．５となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、Ｍｎ、ＮｉとＴｉを含むマンガン酸化物（理論組成（Ｎｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）３Ｏ４）を得た。 Example 6
An aqueous solution containing 0.025 mol / L nickel sulfate (NiSO 4 ), 0.025 mol / L titanyl sulfate (TIOSO 4 ) and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 8.5. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn, Ni and Ti (theoretical composition (Ni 0.025 Ti 0.025 Mn 0.95)). ) 3 O 4 ) was obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｎｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｎｉ＋Ｔｉ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Ni 0.025 Ti 0.025 Mn 0.95 ) 2 O 3. From the weight ratio of the metal composition obtained from ICP, manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Ni + Ti + Mn) molar ratio was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and the main phase was LiNi 0.025 Ti 0.025 Mn 0. 95 O 2 was obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiNi 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain rock salt type LiNi 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and α-NaFeO type 2 type. A lithium composite oxide of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例７
　Ｌｉ／（Ｎｉ＋Ｍｎ）モル比が１．０５になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合したこと以外は実施例６と同様の方法でリチウム複合酸化物を製造し、さらに、電池を作製した。 Example 7
A lithium composite oxide was produced by the same method as in Example 6 except that manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Ni + Mn) molar ratio was 1.05. In addition, a battery was made.
　実施例８
　金属塩水溶液の成分が、０．０２５ｍｏｌ／Ｌの硫酸マグネシウム（ＭｇＳＯ４）、０．０２５ｍｏｌ／Ｌの硫酸チタニル及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いた。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ８．５となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、Ｍｎ、ＭｇとＴｉを含むマンガン酸化物（理論組成（Ｍｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）３Ｏ４）を得た。 Example 8
An aqueous solution containing 0.025 mol / L magnesium sulfate ( ו 4 ), 0.025 mol / L titanyl sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 8.5. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn, Mg and Ti (theoretical composition (Mg 0.025 Ti 0.025 Mn 0.95)). ) 3 O 4 ) was obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｍｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｍｇ＋Ｔｉ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＭｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Mg 0.025 Ti 0.025 Mn 0.95 ) 2 O 3. From the weight ratio of the metal composition obtained from ICP, manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Mg + Ti + Mn) molar ratio was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and the main phase had a zigzag layered structure . LiMg 0.025 Ti 0.025 Mn 0. 95 O 2 was obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＭｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＭｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiMg 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain rock salt type LiMg 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＭｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＭｇ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiMg 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and α-NaFeO type 2 type. A lithium composite oxide of LiMg 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例９
　金属塩水溶液の成分が、０．０５ｍｏｌ／Ｌの硫酸マグネシウム及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いたこと以外は実施例８と同様の方法でＬｉＭｇ０．０５Ｔｉ０．０５Ｍｎ０．９Ｏ２リチウム複合酸化物を製造し、さらに、電池を作製した。 Example 9
LiMg 0.05 Ti 0.05 Mn in the same manner as in Example 8 except that an aqueous solution containing 0.05 mol / L magnesium sulfate and 1.95 mol / L manganese sulfate was used as the component of the metal salt aqueous solution. A 0.9 O 2 lithium composite oxide was produced, and a battery was further produced.
　実施例１０
　金属塩水溶液の成分が、０．０２５ｍｏｌ／Ｌの硫酸亜鉛（ＺｎＳＯ４）、０．０２５ｍｏｌ／Ｌの硫酸チタニル及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いた。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ９．０となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、Ｍｎ、ＺｎとＴｉを含むマンガン酸化物（理論組成（Ｚｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）３Ｏ４）を得た。 Example 10
An aqueous solution containing 0.025 mol / L zinc sulfate (ZnSO 4 ), 0.025 mol / L titanyl sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 9.0. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn, Zn and Ti (theoretical composition (Zn 0.025 Ti 0.025 Mn 0.95)). ) 3 O 4 ) was obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｚｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｚｎ＋Ｔｉ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＺｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was fired in air at 700 ° C. for 12 hours to prepare a theoretical composition (Zn 0.025 Ti 0.025 Mn 0.95 ) 2 O 3. From the weight ratio of the metal composition obtained from ICP, manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Zn + Ti + Mn) molar ratio was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiZn 0.025 Ti 0.025 Mn 0. The main phase had a zigzag layered structure. 95 O 2 was obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＺｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＺｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiZn 0.025 Ti 0.025 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain rock salt type LiZn 0.025 Ti 0.025 Mn 0.95 O 2 . Obtained. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＺｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＺｎ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiZn 0.025 Ti 0.025 Mn 0.95 O 2 having a rock salt type structure was heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and α-NaFeO type 2 type. A lithium composite oxide of LiZn 0.025 Ti 0.025 Mn 0.95 O 2 having a layered domain was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例１１
　金属塩水溶液の成分が、０．０５ｍｏｌ／Ｌの硫酸マグネシウム及び１．９５ｍｏｌ／Ｌの硫酸マンガンを含む水溶液を用いた。なお金属塩水溶液中の全金属の合計濃度は２．０ｍｏｌ／Ｌであった。
　１．０Ｌの反応容器に２００ｇの純水を入れた後、６０℃で昇温、撹拌・維持した。上記金属塩水溶液を、供給速度０．７５ｇ／ｍｉｎで反応容器に添加した。また、上記の供給操作中、酸化剤として空気を供給速度１．０Ｌ／ｍｉｎで反応容器中にバブリングし続けた。さらに、混合液がｐＨ９．０となるように、２．０ｍｏｌ／Ｌの水酸化ナトリウム水溶液を断続的に添加して混合した。反応によって得られた沈殿したスラリーをろ過、洗浄後、１２０℃で１２時間乾燥することで、ＭｎとＭｇを含むマンガン酸化物（理論組成（Ｍｇ０．０５Ｍｎ０．９５）３Ｏ４）を得た。 Example 11
An aqueous solution containing 0.05 mol / L magnesium sulfate and 1.95 mol / L manganese sulfate was used as a component of the metal salt aqueous solution. The total concentration of all metals in the aqueous metal salt solution was 2.0 mol / L.
After 200 g of pure water was placed in a 1.0 L reaction vessel, the temperature was raised at 60 ° C., and the mixture was stirred and maintained. The aqueous metal salt solution was added to the reaction vessel at a supply rate of 0.75 g / min. Further, during the above supply operation, air as an oxidant was continuously bubbled into the reaction vessel at a supply rate of 1.0 L / min. Further, a 2.0 mol / L sodium hydroxide aqueous solution was intermittently added and mixed so that the mixed solution had a pH of 9.0. The precipitated slurry obtained by the reaction is filtered, washed, and dried at 120 ° C. for 12 hours to obtain a manganese oxide containing Mn and Mg (theoretical composition (Mg 0.05 Mn 0.95 ) 3 O 4 ). Obtained.
　上記で得られたマンガン酸化物は７００℃で１２時間、空気中で焼成し、理論組成（Ｍｇ０．０５Ｍｎ０．９５）２Ｏ３を作製した。ＩＣＰから求めた金属組成の重量比から、Ｌｉ／（Ｍｇ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＭｇ０．０５Ｍｎ０．９５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 The manganese oxide obtained above was calcined in air at 700 ° C. for 12 hours to prepare a theoretical composition (Mg 0.05 Mn 0.95 ) 2 O 3. From the weight ratio of the metal composition obtained from ICP, manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / (Mg + Mn) molar ratio was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiMg 0.05 Mn 0.95 O 2 having a zigzag layered main phase was added. Obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＭｇ０．０５Ｍｎ０．９５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＭｇ０．０５Ｍｎ０．９５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。 The obtained LiMg 0.05 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container in an Ar atmosphere for 36 hours to obtain a rock salt type LiMg 0.05 Mn 0.95 O 2. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
　次に、岩塩型構造を有するＬｉＭｇ０．０５Ｍｎ０．９５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＭｇ０．０５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 Next, LiMg 0.05 Mn 0.95 O 2 having a rock salt type structure is heat-treated in Ar gas at 600 ° C. for 12 hours to form a zigzag layered structure as a mother structure, and a domain of α-NaFeO type 2 layered structure. A lithium composite oxide of LiMg 0.05 Mn 0.95 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　実施例１２
　炭酸マンガン（ＭｎＣＯ３）を７００℃で１２時間、空気中で焼成し、理論組成（Ｍｎ２Ｏ３）のマンガン酸化物を作製する。金属組成のＶ／（Ｖ＋Ｍｎ）モル比が０．０５、及び、Ｌｉ／（Ｖ＋Ｍｎ）モル比が１．０になるようにマンガン酸化物、市販の酸化バナジウム（Ｖ）（Ｖ２Ｏ５、和光社製）と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＶ０．０５Ｍｎ０．９５Ｏ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 Example 12
Manganese carbonate (MnCO 3 ) is calcined in air at 700 ° C. for 12 hours to prepare a manganese oxide having a theoretical composition (Mn 2 O 3). Manganese oxide, commercially available vanadium oxide (V) (V 2 O 5 , Wako) so that the V / (V + Mn) molar ratio of the metal composition is 0.05 and the Li / (V + Mn) molar ratio is 1.0. ) And commercially available lithium carbonate were dry-mixed in a dairy pot for 20 minutes. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, cooled to room temperature, and LiV 0.05 Mn 0.95 O 2 having a zigzag layered main phase was added. Obtained. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＶ０．０５Ｍｎ０．９５Ｏ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＶ０．０５Ｍｎ０．９５Ｏ２を得た。メカニカルミリングにはジルコニア製を使用し、リチウム複合酸化物試料１．５ｇに直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて行った。
　次に、岩塩型構造を有するＬｉＶ０．０５Ｍｎ０．９５Ｏ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＶ０．０５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記＜電池の作製＞に従って電池を作製した。 The obtained LiV 0.05 Mn 0.95 O 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain a rock salt type LiV 0.05 Mn 0.95 O 2. A zirconia product was used for mechanical milling, and three 10 mm diameter balls, 10 5 mm diameter balls and 2 g 1 mm diameter balls were placed in 1.5 g of a lithium composite oxide sample.
Next, LiV 0.05 Mn 0.95 O 2 having a rock salt type structure was heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and a domain of α-NaFeO type 2 layered structure. A lithium composite oxide of LiV 0.05 Mn 0.95 O 2 having the above was obtained. Further, using the obtained lithium composite oxide, a battery was produced according to the above <Production of Battery>.
　実施例１３
　ジルコニア製密閉容器に、実施例６で得られた、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を０．４ｇ、複合化材（商品名：デンカブラック、デンカ社製）を０．０５ｇ、直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて１００ｒｐｍで１２時間メカニカルミリングを行って、カーボン複合化リチウム複合酸化物を得た。
　次に、得られたカーボン複合化リチウム複合酸化物とバインダ（１０ｗｔ％ＰｖｄＦ／Ｎ－Ｍｅｔｈｙｌ－２－Ｐｙｒｒｏｌｉｄｏｎｅ溶液）を重量比９０：１０で混合器を用いて均一混合して、正極材インクを作製し、その正極材インクを用いた以外は、上記の＜電池の作製＞に従って電池を作製した。 Example 13
A lithium composite of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a zigzag layered structure as a mother structure and a domain of an α-NaFeO type 2 layered structure obtained in Example 6 in a closed container made of zirconia. 0.4 g of oxide, 0.05 g of composite material (trade name: Denka Black, manufactured by Denka), 3 balls with a diameter of 10 mm, 10 balls with a diameter of 5 mm and 2 g of a ball with a diameter of 1 mm are put in and 12 at 100 rpm. Time mechanical milling was performed to obtain a carbon composite lithium composite oxide.
Next, the obtained carbon composite lithium composite oxide and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) were uniformly mixed using a mixer at a weight ratio of 90:10 to obtain a positive electrode material ink. A battery was manufactured according to the above <Battery preparation> except that the positive electrode material ink was used.
　実施例１４
　ジルコニア製密閉容器に、実施例６で得られた、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＮｉ０．０２５Ｔｉ０．０２５Ｍｎ０．９５Ｏ２のリチウム複合酸化物を０．４ｇ、カーボンナノチューブ（Ｓｈｅｎｚｈｅｎ　ＳＵＳＮ　Ｎａｎｏｔｅｃｈ社製）を０．０５ｇ、直径１０ｍｍボールを３個、直径５ｍｍボールを１０個及び直径１ｍｍボールを２ｇ入れて１００ｒｐｍで１２時間メカニカルミリングを行って、カーボン複合化リチウム複合酸化物を得た。
　次に、得られたカーボン複合化リチウム複合酸化物とバインダ（１０ｗｔ％ＰｖｄＦ／Ｎ－Ｍｅｔｈｙｌ－２－Ｐｙｒｒｏｌｉｄｏｎｅ溶液）を重量比９０：１０で混合器を用いて均一混合して、正極材インクを作製し、その正極材インクを用いた以外は、上記の＜電池の作製＞に従って電池を作製した。 Example 14
A lithium composite of LiNi 0.025 Ti 0.025 Mn 0.95 O 2 having a zigzag layered structure as a mother structure and a domain of an α-NaFeO type 2 layered structure obtained in Example 6 in a closed container made of zirconia. Mechanical milling was performed at 100 rpm for 12 hours with 0.4 g of oxide, 0.05 g of carbon nanotube (manufactured by Shenzhen SUSN Nanotech), 3 balls with a diameter of 10 mm, 10 balls with a diameter of 5 mm and 2 g of a ball with a diameter of 1 mm. A carbon composite lithium composite oxide was obtained.
Next, the obtained carbon composite lithium composite oxide and a binder (10 wt% PvdF / N-Methyl-2-Pyrrolidone solution) were uniformly mixed using a mixer at a weight ratio of 90:10 to obtain a positive electrode material ink. A battery was manufactured according to the above <Battery preparation> except that the positive electrode material ink was used.
　比較例１
　炭酸マンガン（ＭｎＣＯ３）を７００℃で１２時間、空気中で焼成し、理論組成（Ｍｎ２Ｏ３）のマンガン酸化物を作製した。金属組成のＬｉ／Ｍｎモル比が１．０になるようにマンガン酸化物と市販の炭酸リチウムを乳鉢で２０分間乾式混合した。得られた混合粉を焼成皿に入れて、９００℃で１２時間、Ａｒガス中で加熱を行い、室温まで冷却して主相がジグザグ層状構造を有するＬｉＭｎＯ２を得た。昇温速度と降温速度は１０℃／ｍｉｎとした。 Comparative Example 1
Manganese carbonate (MnCO 3 ) was calcined in air at 700 ° C. for 12 hours to prepare a manganese oxide having a theoretical composition (Mn 2 O 3). Manganese oxide and commercially available lithium carbonate were dry-mixed in a mortar for 20 minutes so that the Li / Mn molar ratio of the metal composition was 1.0. The obtained mixed powder was placed in a baking dish, heated at 900 ° C. for 12 hours in Ar gas, and cooled to room temperature to obtain LiMnO 2 having a zigzag layered main phase. The temperature raising rate and the temperature lowering rate were set to 10 ° C./min.
　得られたＬｉＭｎＯ２はＡｒ雰囲気の密閉容器中６００ｒｐｍで３６時間メカニカルミリングを行い、岩塩型ＬｉＭｎＯ２を得た。
　次に、岩塩型構造を有するＬｉＭｎＯ２を６００℃で１２時間、Ａｒガス中で熱処理を行い、ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するＬｉＭｎＯ２のリチウム複合酸化物を得た。さらに、得られたリチウム複合酸化物を用い、上記の＜電池の作製＞に従って電池を作製した。 The obtained LiMnO 2 was mechanically milled at 600 rpm in a closed container with an Ar atmosphere for 36 hours to obtain a rock salt type LiMnO 2.
Next, LiMnO 2 having a rock salt type structure is heat-treated at 600 ° C. for 12 hours in Ar gas to form a zigzag layered structure as a mother structure, and lithium composite oxidation of LiMnO 2 having a domain of α-NaFeO type 2 layered structure. I got something. Further, using the obtained lithium composite oxide, a battery was manufactured according to the above <Battery Fabrication>.
　比較例２
　岩塩型構造を有するＬｉＭｎＯ２を７００℃で１２時間、Ａｒガス中で熱処理を行ったこと以外は比較例１と同様の方法でリチウム複合酸化物を製造し、さらに、電池を作製した。
　実施例１～１４及び比較例１、２の作製条件及び物性を表１に示した。 Comparative Example 2
A lithium composite oxide was produced in the same manner as in Comparative Example 1 except that LiMnO 2 having a rock salt structure was heat-treated at 700 ° C. for 12 hours in Ar gas, and a battery was further produced.
Table 1 shows the production conditions and physical properties of Examples 1 to 14 and Comparative Examples 1 and 2.
Figure JPOXMLDOC01-appb-T000001
  
Figure JPOXMLDOC01-appb-T000001
  
＜リチウム複合酸化物の平均粒子径＞
　実施例１～１４及び比較例１、２で製造されたリチウム複合酸化物の粒度径測定を行い、その結果の平均粒子径（Ｄ５０）を表１に示した。実施例で作製したリチウム複合酸化物は、異種金属（Ｃｏ、Ｆｅ、Ｎｉ＋Ｔｉ、Ｍｇ＋Ｔｉ、Ｚｎ＋Ｔｉ、Ｍｇ、Ｖ）置換からなる粒度分布の変化はされていないことが確認できた。 <Average particle size of lithium composite oxide>
The particle size diameters of the lithium composite oxides produced in Examples 1 to 14 and Comparative Examples 1 and 2 were measured, and the average particle size (D50) of the results is shown in Table 1. It was confirmed that the lithium composite oxide produced in the examples did not change the particle size distribution composed of substitutions with different metals (Co, Fe, Ni + Ti, Mg + Ti, Zn + Ti, Mg, V).
＜リチウム複合酸化物のＢＥＴ比表面積＞
　実施例１～１４及び比較例１、２で製造されたリチウム複合酸化物のＢＥＴ比表面積の測定を行い、その結果を表１に示した。実施例で作製したリチウム複合酸化物は、異種金属置換からなるＢＥＴ比表面積の変化はされていないことが確認できた。 <BET specific surface area of lithium composite oxide>
The BET specific surface area of the lithium composite oxides produced in Examples 1 to 14 and Comparative Examples 1 and 2 was measured, and the results are shown in Table 1. It was confirmed that the lithium composite oxide produced in the examples did not change the BET specific surface area consisting of dissimilar metal substitutions.
＜リチウム複合酸化物の結晶性＞
　実施例１～１２及び比較例１、２のリチウム複合酸化物粉末に対して１０～２０°のＸＲＤパターンを確認し、その結果を図３の（３ａ）、（３ｂ）に示した。図３の実施例１～１２及び比較例１、２により、本発明工程で作製したリチウム複合酸化物は１５．３±１．０°（Ａ）に示される直方晶系（０１０）面と１８．２±１．０°（Ｂ）に示される単斜晶系（００１）面のピークが確認できた。本発明工程で作製したリチウム複合酸化物は図３のように直方晶系を母構造とし、単斜晶をドメインとする構造であることを確認できた。さらに（Ａ／Ｂ）ピーク積算強度比の算出を行い、その結果を表１に示した。 <Crystallinity of lithium composite oxide>
XRD patterns of 10 to 20 ° were confirmed with respect to the lithium composite oxide powders of Examples 1 to 12 and Comparative Examples 1 and 2, and the results are shown in FIGS. 3a and 3b. According to Examples 1 to 12 and Comparative Examples 1 and 2 in FIG. 3, the lithium composite oxide produced in the step of the present invention has the orthorhombic (010) plane and 18 shown in 15.3 ± 1.0 ° (A). The peak of the monoclinic (001) plane shown at .2 ± 1.0 ° (B) was confirmed. As shown in FIG. 3, it was confirmed that the lithium composite oxide produced in the process of the present invention has a structure having an orthorhombic system as a mother structure and a monoclinic crystal as a domain. Further, the (A / B) peak integrated intensity ratio was calculated, and the results are shown in Table 1.
　実施例２、６及び比較例２のリチウム複合酸化物粉末に対して１０～９０°のＸＲＤパターンを確認し、その結果を図４に示した。本発明工程で作製したリチウム複合酸化物は、直方晶系（０１０）面、（０１１）面、（２００）面、（０２１）面に強いピークと単斜晶系（００１）面に弱いピークを有していることが分かった。すなわち、直方晶系ジグザグ層状構造を母構造とし、α－ＮａＦｅＯ２型層状構造のドメインを有するリチウム複合酸化物になっていることが分かった。さらに、本発明工程で作製したリチウム複合酸化物は、異種金属置換からなる結晶構造は変化させていないことが確認できた。 An XRD pattern of 10 to 90 ° was confirmed with respect to the lithium composite oxide powders of Examples 2 and 6 and Comparative Example 2, and the results are shown in FIG. The lithium composite oxide produced in the process of the present invention has a strong peak on the orthorhombic (010) plane, (011) plane, (200) plane, and (021) plane and a weak peak on the monoclinic (001) plane. It turned out to have. That is, it was found that the lithium composite oxide has an orthorhombic zigzag layered structure as a mother structure and has a domain of α-NaFeO type 2 layered structure. Furthermore, it was confirmed that the lithium composite oxide produced in the process of the present invention did not change the crystal structure composed of dissimilar metal substitutions.
＜高容量及び高出力特性＞
　実施例１～１４及び比較例１、２で製造されたリチウム複合酸化物を正極活物質として用いた正極の充電・放電測定から求めた０．３Ｃ、１．０Ｃ、２．０Ｃでの放電容量、及び０．３Ｃの放電容量、平均放電電位（Ｖ）、電極密度（ｋｇ／Ｌ）から求めたエネルギー密度を表２に示した。 <High capacity and high output characteristics>
Discharge capacity at 0.3C, 1.0C, 2.0C obtained from charge / discharge measurement of the positive electrode using the lithium composite oxide produced in Examples 1 to 14 and Comparative Examples 1 and 2 as the positive electrode active material. , And the energy density obtained from the discharge capacity of 0.3C, the average discharge potential (V), and the electrode density (kg / L) are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
  
Figure JPOXMLDOC01-appb-T000002
  
　さらに実施例２、５、６、８、１０、１２、１３、１４及び比較例２で製造されたリチウム複合酸化物を正極活物質として用いた正極の０．３Ｃで行った放電測定の結果を図５の（５ａ）、（５ｂ）、（５ｃ）に示した。エネルギー密度の計算を以下に示す。
　エネルギー密度（Ｗｈ／ｋｇ）＝放電容量（Ａｈ／ｋｇ）×平均放電電位（Ｖ）
　エネルギー密度（Ｗｈ／Ｌ）＝放電容量（Ａｈ／ｋｇ）×平均放電電位（Ｖ）×電極密度（ｋｇ／Ｌ）
　上記計算に使用された電極密度は上記＜電池の作製＞の記載に従って作製した電極から、集電体であるアルミニウムホイルを除く、正極活物質＋導電材＋バインダの重量と電極の直径と厚みから求めた体積で算出した。 Further, the results of the discharge measurement performed at 0.3 C of the positive electrode using the lithium composite oxide produced in Examples 2, 5, 6, 8, 10, 12, 13, 14 and Comparative Example 2 as the positive electrode active material are shown. It is shown in (5a), (5b), and (5c) of FIG. The calculation of energy density is shown below.
Energy density (Wh / kg) = discharge capacity (Ah / kg) x average discharge potential (V)
Energy density (Wh / L) = Discharge capacity (Ah / kg) x Average discharge potential (V) x Electrode density (kg / L)
The electrode density used in the above calculation is based on the weight of the positive electrode active material + conductive material + binder and the diameter and thickness of the electrodes, excluding the aluminum foil that is the current collector, from the electrodes manufactured according to the description of <Battery fabrication> above. It was calculated based on the obtained volume.
　表２で示された０．３Ｃの放電容量結果から、実施例１～１４は金属元素置換をされなく製造された比較例１、２より出力特性の改良性が示された。これは、１．０Ｃ、２．０Ｃでの放電容量も同様な結果を示された。
　表２で示された実施例１～１４で製造された正極のエネルギー密度も比較例１、２より上回って、高容量で高出力を持つリチウム二次電池を達成した。特に、実施例１３、１４はカーボンがリチウム複合酸化物の周辺に均一分布され、出力特性がさらに改善された効果を示した。
　実施例６、１３のリチウム複合酸化物のＳＥＭ像を図６に示した。実施例１３は、実施例６のリチウム複合酸化物についてカーボン複合化を行うことで、活物質の二次粒子が粉砕によりもっと均一な粒径になることがＳＥＭ像で確認できた。 From the discharge capacity results of 0.3C shown in Table 2, the improvement of the output characteristics of Examples 1 to 14 was shown from Comparative Examples 1 and 2 manufactured without metal element substitution. The same results were shown for the discharge capacities at 1.0C and 2.0C.
The energy densities of the positive electrodes manufactured in Examples 1 to 14 shown in Table 2 also exceeded those of Comparative Examples 1 and 2, and a lithium secondary battery having a high capacity and a high output was achieved. In particular, in Examples 13 and 14, carbon was uniformly distributed around the lithium composite oxide, showing the effect of further improving the output characteristics.
The SEM images of the lithium composite oxides of Examples 6 and 13 are shown in FIG. In Example 13, it was confirmed from the SEM image that the secondary particles of the active material had a more uniform particle size by pulverization by carbon-compositing the lithium composite oxide of Example 6.
　本発明のリチウム複合酸化物は、安価な高容量・高出力の正極活物質として、リチウム二次電池用正極活物質の分野で使用が期待される。
　なお、２０２０年０５月２２日に出願された日本特許出願２０２０－０８９６６４号および２０２０年０８月２６日に出願された日本特許出願２０２０－１４２８７５号の明細書、特許請求の範囲、要約書および図面の全内容をここに引用し、本発明の明細書の開示として、取り入れるものである。 The lithium composite oxide of the present invention is expected to be used in the field of positive electrode active materials for lithium secondary batteries as an inexpensive high-capacity, high-output positive electrode active material.
The specification, claims, abstract and drawings of Japanese Patent Application No. 2020-089664 filed on May 22, 2020 and Japanese Patent Application No. 2020-142875 filed on August 26, 2020. The entire contents of the above are cited here and incorporated as disclosure of the specification of the present invention.

Claims (9)

  1. 　組成式ＬｉｘＭｅｙＭｎ１－ｙＯ２（但し、０＜ｘ≦１．２であり、０＜ｙ≦０．２である。ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属元素である。）で示され、直方晶系ジグザグ層状構造を母構造とし、単斜晶又は菱面体晶α-ＮａＦｅＯ２型層状構造のドメインを有し、かつ、粉体Ｘ線回折で１５．３±１．０°に観測される回折ピーク積分強度（Ａ）と１８．２±１．０°に観測される回折ピーク積分強度（Ｂ）との強度比（Ａ／Ｂ）が０．５以上であることを特徴とするリチウム複合酸化物。 Composition formula Li x Me y Mn 1-y O 2 (However, 0 <x ≦ 1.2 and 0 <y ≦ 0.2. Me is Al, Co, Cr, Cu, Fe, Mg, Mo. , Nb, Ni, Si, Ti, V, W, Zn, and one or more metal elements selected from the group consisting of Zr.). Diffraction peak integrated intensity (A) and 18.2 ± observed at 15.3 ± 1.0 ° by powder X-ray diffraction with a domain of crystal or rhombic crystal α-NaFeO type 2 layered structure. A lithium composite oxide characterized in that the intensity ratio (A / B) to the diffraction peak integrated intensity (B) observed at 1.0 ° is 0.5 or more.
  2. 　前記ＭｅがＡｌ、Ｃｏ、Ｆｅ、Ｍｇ、Ｎｂ、Ｎｉ、Ｔｉ、及びＺｎからなる群より選ばれる１種以上の金属元素である請求項１に記載のリチウム複合酸化物。 The lithium composite oxide according to claim 1, wherein Me is one or more metal elements selected from the group consisting of Al, Co, Fe, Mg, Nb, Ni, Ti, and Zn.
  3. 　ＢＥＴ比表面積が８．０ｍ２／ｇ以下であり、平均粒子径（Ｄ５０）が、０．２～５．０μｍである請求項１又は２に記載のリチウム複合酸化物。 The lithium composite oxide according to claim 1 or 2, wherein the BET specific surface area is 8.0 m 2 / g or less, and the average particle size (D50) is 0.2 to 5.0 μm.
  4. 　導電性を有するカーボン若しくは金属で複合化されている請求項１～３のいずれかの項に記載のリチウム複合酸化物。 The lithium composite oxide according to any one of claims 1 to 3, which is composited with conductive carbon or metal.
  5. 　請求項１～４のいずれかの項に記載のリチウム複合酸化物の製造方法であって、組成式（ＭｅｙＭｎ１－ｙ）ａＯｂ（但し、１．３＜ａ／ｂ＜１．６であり、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示され、金属イオンの平均酸化数が２．６以上３．３以下であるマンガン化合物とリチウム化合物を混合して焼結し、主相がジグザグ層状構造を有するＬｉｘＭｅｙＭｎ１－ｙＯ２で表されるリチウム複合酸化物を作製する工程、及び、前記工程で得られたＬｉｘＭｅｙＭｎ１－ｙＯ２にメカニカルミリングを施し、次いで不活性ガス中で熱処理することを特徴とする製造方法。 The method for producing a lithium composite oxide according to any one of claims 1 to 4, wherein the composition formula (Me y Mn 1-y ) a Ob (where 1.3 <a / b <1. 6 and 0 <y≤0.2, from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr. A manganese compound and a lithium compound, which are represented by (one or more selected metals) and have an average oxidation number of metal ions of 2.6 or more and 3.3 or less, are mixed and sintered, and the main phase has a zigzag layered structure. step of preparing a lithium composite oxide represented by Li x Me y Mn 1-y O 2 , and is subjected to mechanical milling in Li x Me y Mn 1-y O 2 obtained in the previous step, then the inert A manufacturing method characterized by heat treatment in gas.
  6. 　請求項１～４のいずれかの項に記載のリチウム複合酸化物の製造方法であって、金属組成がＭｅｙＭｎ１－ｙ（但し、０＜ｙ≦０．２であり、ＭｅがＡｌ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｎｂ、Ｎｉ、Ｓｉ、Ｔｉ、Ｖ、Ｗ、Ｚｎ、及びＺｒからなる群より選ばれる１種以上の金属）で示されるマンガン化合物とリチウム化合物を混合し、次いでアルカリ性水溶液中で水熱処理することを特徴とする製造方法。 The method for producing a lithium composite oxide according to any one of claims 1 to 4, wherein the metal composition is Me y Mn 1-y (provided that 0 <y ≦ 0.2, and Me is Al. A manganese compound and a lithium compound represented by (one or more metals selected from the group consisting of Co, Cr, Cu, Fe, Mg, Mo, Nb, Ni, Si, Ti, V, W, Zn, and Zr) are mixed. Then, a production method characterized by hydrothermal treatment in an alkaline aqueous solution.
  7. 　得られるリチウム複合酸化物を、次いで、導電性を有するカーボン若しくは金属の複合化剤とともにメカニカルミリングする請求項５又は６に記載の製造方法。 The production method according to claim 5 or 6, wherein the obtained lithium composite oxide is then mechanically milled together with a conductive carbon or metal complexing agent.
  8. 　請求項１～４のいずれかの項に記載のリチウム複合酸化物を含む電極。 The electrode containing the lithium composite oxide according to any one of claims 1 to 4.
  9. 　請求項８に記載の電極を正極に使用したリチウム二次電池。 A lithium secondary battery using the electrode according to claim 8 for the positive electrode.
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