WO2015107839A1 - Positive electrode active material - Google Patents

Positive electrode active material Download PDF

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Publication number
WO2015107839A1
WO2015107839A1 PCT/JP2014/083868 JP2014083868W WO2015107839A1 WO 2015107839 A1 WO2015107839 A1 WO 2015107839A1 JP 2014083868 W JP2014083868 W JP 2014083868W WO 2015107839 A1 WO2015107839 A1 WO 2015107839A1
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Prior art keywords
compound
positive electrode
active material
electrode active
amount
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PCT/JP2014/083868
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French (fr)
Japanese (ja)
Inventor
雄一 上村
西島　主明
西村　直人
智寿 吉江
貴洋 松山
俊平 西中
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シャープ株式会社
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Publication of WO2015107839A1 publication Critical patent/WO2015107839A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • 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
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5805—Phosphides
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a positive electrode active material. More specifically, the present invention relates to a positive electrode active material that can provide a lithium ion secondary battery that can be charged and discharged with high input / output.
  • Secondary batteries are attracting attention as not only small batteries for portable electronic devices, but also large-capacity electricity storage devices for in-vehicle use and power storage.
  • lithium ion secondary batteries have higher battery capacity than other batteries (for example, lead storage batteries, nickel cadmium batteries, nickel hydride batteries), and are expected to be used as power storage devices. Yes.
  • a lithium ion secondary battery is a battery that includes a positive electrode, a separator, and a negative electrode in this order, and uses insertion and desorption of lithium ions to and from an active material layer that constitutes the positive electrode and the negative electrode.
  • LiCoO 2 is well known as a positive electrode active material for lithium ion secondary batteries.
  • LiCoO 2 is not sufficiently safe, and since Co is a rare element, it has been difficult to provide an inexpensive lithium ion secondary battery.
  • a positive electrode active material made of a phosphoric acid composite compound using Fe or Mn instead of Co has been reported (for example, International Publication No. WO2010 / 150889: Patent Document 1).
  • This patent document 1 makes it a subject to control the fall of charging / discharging capacity.
  • the melted product of Li 2 O, MO (FeO, MnO, CoO and / or NiO) and P 2 O 5 is pulverized while being mixed with glucose, sucrose or acetylene black. And the pulverized product is heated to obtain a positive electrode active material.
  • An object of the present invention is to provide a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output.
  • the positive electrode active material according to one embodiment of the present invention is a positive electrode active material for a lithium ion secondary battery
  • the positive electrode active material is Li, M, Z, P, Si, and O (M is one or both of Fe and Mn, and Z is a group consisting of Co, Ni, Zr, Sn, Al, and Y).
  • the second compound is (I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element (Ii)
  • M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si.
  • the first compound and the second compound, as a mixture thereof, have the following general formula (1): Li a M b Z c P d Si e O f (1) (1.0 ⁇ a ⁇ 1.1, 0.75 ⁇ b ⁇ 0.99, 0 ⁇ c ⁇ 0.3, 0.5 ⁇ d ⁇ 1.1, 0 ⁇ e ⁇ 0.6, 3 ⁇ f ⁇ 5).
  • a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output can be provided.
  • the cause of the above problem is the state of the interface of the phosphoric acid composite compound constituting the positive electrode active material.
  • the cause of the above problem is the state of the interface of the phosphoric acid composite compound constituting the positive electrode active material.
  • FIG. 1A lithium ions are charged and discharged from the inside of the phosphoric acid complex compound 1 to the phosphoric acid complex compound / electrolyte interface and the phosphoric acid complex compound / phosphoric acid compound compound interface.
  • 2 indicates a positive electrode current collector, and an arrow indicates a lithium ion diffusion path. Lithium ions obtain a driving force larger than their interfacial energy, so that they cross over the interface and diffuse into other phosphate complex compounds or electrolytes.
  • the cathode active material of the present invention includes at least one each of a first compound that is a phosphoric acid complex compound and a second compound that is composed of a compound of a constituent element of the first compound.
  • the first compound is Li, M, Z, P, Si and O (M is one or both of Fe and Mn, Z is Co, Ni, Zr, Sn, Al and And at least one element selected from the group consisting of Y or a combination thereof.
  • the first compound may be a single compound or a mixture of a plurality of compounds.
  • Specific first compounds include: Li / Fe / Co / P / Si / O, Li / Fe / Ni / P / Si / O, Li / Fe / Zr / P / Si / O, Li / Fe / Sn / P / Si / O, Li / Fe / Al / P / Si / O, Li / Fe / Y / P / Si / O, Li / Fe / Zr / P / Al / O; Li / Mn / Co / P / Si / O, Li / Mn / Ni / P / Si / O, Li / Mn / Zr / P / Si / O, Li / Mn / Sn / P / Si / O, Li / Mn / Al / P / Si / O, Li / Mn / Y / P / Si / O, Li / Mn / Zr / P / Al
  • the second compound comprises one or both of an oxide and a phosphide.
  • the second compound is (I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element (Ii) When M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si. Species selected.
  • an oxide and a phosphide of an element selected from Zr, Sn, Al and Y may further be included.
  • the second compound is a compound having lithium ion conductivity, the interfacial energy of lithium ions when diffusing the interface between the first compound and the electrolyte and the first compound can be reduced.
  • the second compound may be a single compound or a mixture of a plurality of compounds.
  • Specific examples of the second compound include oxides such as ZrO 2 , SiO 2 , Al 2 O 3 and SnO 2 , Li 3 PO 4 , FePO 4 , LiH 2 PO 4 , Li 2 HPO 4 , H 3 PO 4 , Examples thereof include phosphorus compounds such as Zr 2 P and Zr 3 P.
  • a is less than 1.0, the amount of Li in the mixture decreases, and a sufficient capacity may not be obtained when the secondary battery is assembled.
  • a is larger than 1.1, a Li compound (for example, Li 2 O, LiOH, etc.) that does not belong to the first compound or the second compound is formed.
  • the surface of the current collector Al foil or the like
  • the amount of metal that causes a valence change in the first compound is reduced, and the amount of Li that is desorbed from the first compound during charging of the secondary battery is reduced, so that sufficient capacity is obtained. It may not be possible.
  • H 3 PO 4 is formed which does not belong to the first compound or the second compound.
  • the surface of the current collector such as Al foil
  • the unit cell volume of the obtained first compound is greatly changed by the insertion / desorption of Li, and the capacity is remarkably reduced when the secondary battery is repeatedly charged and discharged.
  • e is larger than 0.6
  • SiO 2 as the second compound is formed on the surface of the first compound, and the transfer of electrons to the first compound is significantly reduced. In some cases, a sufficient capacity cannot be obtained.
  • f is set to satisfy the charge compensation in the crystal of the second compound and the value that can be set to satisfy the charge compensation in the crystal of the first compound, with the valence of oxygen being “ ⁇ 2”. This is the total value to be obtained.
  • a, b, c, d and e are 1.01 ⁇ a ⁇ 1.1, 0.875 ⁇ b ⁇ 0.99, 0 ⁇ c ⁇ 0.125, 0.75 ⁇ d ⁇ 1.05, 0 It is preferable that ⁇ e ⁇ 0.25. If a, b, c, d and e are out of this range, the average particle size of the particles may not be controlled within an appropriate range when the positive electrode active material is produced by a general production method.
  • A, b, c, d and e are 1.01 ⁇ a ⁇ 1.05, 0.94 ⁇ b ⁇ 0.99, 0.01 ⁇ c ⁇ 0.06, 0.97 ⁇ d ⁇ 1.
  • the average particle size of the particles may not be controlled within an appropriate range when the positive electrode active material is produced by the solid phase method.
  • the proportion of the first compound and the second compound in the mixture is preferably 0.1 to 10 parts by weight of the second compound with respect to 100 parts by weight of the first compound.
  • the ratio of the second compound is less than 0.1 parts by weight, the reduction of the interfacial energy of lithium ions may not be sufficient.
  • the amount is more than 10 parts by weight, the amount of lithium in the mixture decreases, and the charge / discharge capacity may decrease.
  • a more preferable ratio of the second compound is 1 to 5 parts by weight. If the ratio of the second compound is less than 1 part by weight, more physical contacts between the conductive material and the current collector are required when the positive electrode is used, and the electron conductivity may be insufficient.
  • the proportion of the second compound is less than 5 parts by weight, an excessive amount of the second compound may increase on the surface of the positive electrode active material, and in the case of the positive electrode, more binder is required and the electron conductivity becomes insufficient. Sometimes.
  • the ratio of the first compound and the second compound from the mixture can be calculated as follows.
  • the first compound and the second compound obtained from results of crystal structure analysis performed XRD measurement, except the crystal structure of a first compound Li a M b Z c P d Si e O f
  • the second compound can be identified by performing a qualitative analysis on the diffraction peak corresponding to.
  • an element that is not contained in the second compound was identified, it shall be all included in a first compound Li a M b Z c P d Si e O f, and the first compound is electrically neutral
  • the elemental composition ratio of the first compound can be determined.
  • the second compound can be quantified by subtracting the element of the first compound from the quantification result of each element of the first compound and the second compound obtained by ICP-MS measurement.
  • the second compound is preferably located on the surface of the positive electrode active material from the viewpoint of reducing the interfacial energy of lithium ions.
  • the position on the surface can be confirmed by, for example, a lattice image or an electron beam diffraction image obtained by TEM observation of a sample embedded in a resin and obtained by FIB processing.
  • the positive electrode active material is an aggregate of particles containing a mixture of the first compound and the second compound
  • the second compound is located on the surface of each particle as shown in FIG. Preferably it is.
  • the average particle diameter of the particles is preferably 0.1 to 500 ⁇ m.
  • the thickness is 1 to 50 ⁇ m. If the thickness is within this range, the amount of the conductive material contained in the positive electrode active material can be easily controlled to an appropriate amount.
  • the positive electrode active material is a raw material such as carbonate, hydroxide, chloride, sulfate, acetate, oxide, oxalate, nitrate, alkoxide, etc. It can be manufactured by using a combination.
  • the raw material may contain hydration water.
  • methods such as a firing method, a solid phase method, a sol-gel method, a melt quench method, a mechanochemical method, a coprecipitation method, a hydrothermal method, and a spray pyrolysis method can be used.
  • a firing method under an inert atmosphere for example, a nitrogen atmosphere
  • firing conditions are 400 to 650 ° C. for 1 to 24 hours
  • the formation of the second compound can be performed by adding the raw material of the second compound desired to be formed to the raw material corresponding to the configuration of the first compound desired to be formed, and producing the positive electrode active material by the above method.
  • the obtained positive electrode active material can be adjusted to a desired average particle size by subjecting to a known pulverization method and sieving method.
  • the positive electrode includes a current collector (positive electrode current collector 2 in FIG. 1B) and a positive electrode active material layer on the current collector.
  • the positive electrode active material layer contains the said positive electrode active material and a binder.
  • binder examples include (meth) acrylic resin, styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), and the like.
  • the binder may include 1 to 8 parts by weight with respect to 100 parts by weight of the positive electrode active material.
  • the binder content is less than 1 part by weight, the binding ability may be insufficient.
  • the binder content is more than 8 parts by weight, the amount of active material contained in the positive electrode decreases, and the resistance or polarization of the positive electrode increases. The discharge capacity may be reduced.
  • a conductive material and a thickening material may be included.
  • acetylene black carbon, graphite, natural graphite, artificial graphite, needle coke, or the like can be used.
  • carboxymethyl cellulose As the thickener, carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be used.
  • the contents of the thickener and the conductive material are preferably about 0.5 to 5 parts by weight for the thickener and about 1 to 6 parts by weight for the conductive material with respect to 100 parts by weight of the positive electrode active material. If the content of the thickener is less than 0.5 parts by weight, the thickening ability may be insufficient. If it is more than about 5 parts by weight, the amount of the active material contained in the positive electrode decreases, and the positive electrode resistance or Polarization and the like may increase and the discharge capacity may decrease. If the content of the conductive material is less than 1 part by weight, the resistance or polarization of the positive electrode may increase and the discharge capacity may decrease, and if it exceeds about 6 parts by weight, the amount of active material contained in the positive electrode will decrease. As a result, the discharge capacity as the positive electrode may be reduced.
  • the thickness of the positive electrode active material layer is preferably about 0.01 to 2 mm. If it is too thick, the conductivity is lowered, and if it is too thin, the capacity per unit area is lowered. Note that the positive electrode active material layer obtained by coating and drying may be subjected to press treatment in order to increase the packing density of the lithium-containing metal oxide.
  • the positive electrode active material layer can be produced, for example, by a known method such as applying a slurry obtained by mixing a positive electrode active material and a binder, optionally together with a thickener and a conductive material, in a solvent to a current collector.
  • Solvents include water, N-methyl-2-pyrrolidone, toluene, cyclohexane, dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl acetate, methyl acrylate, diethyltriamine, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, etc.
  • Organic solvents can be used.
  • (B) Current collector As the current collector, foamed (porous) metal having continuous pores, metal formed in a honeycomb shape, sintered metal, expanded metal, non-woven fabric, plate, foil, perforated plate, foil Etc. can be used.
  • the positive electrode current collector is usually made of aluminum.
  • a lithium ion secondary battery includes a positive electrode and a negative electrode, and a separator positioned between the positive electrode and the negative electrode.
  • a lithium ion secondary battery that can be charged / discharged at high input / output can be obtained.
  • high output is the capacity obtained at 10 C relative to the capacity obtained at 0.1 C. It means the ratio (rate characteristic).
  • the positive electrode of said (II) can be used for a positive electrode.
  • Negative electrode A negative electrode having a negative electrode active material layer on a current collector can be used.
  • the negative electrode active material layer can be produced by a known method. Specifically, it can be produced in the same manner as described in the method for producing the positive electrode active material layer. For example, the binder (styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), etc.) described in the column of the positive electrode active material layer, a conductive material, and a thickener are mixed with the negative electrode active material, and then the mixed powder
  • SBR styrene butadiene rubber
  • PVDF polyvinylidene fluoride
  • the negative electrode active material layer can be obtained by molding the molded body into a sheet shape and press-bonding the obtained molded body to stainless steel and a current collector. Further, as described in the method for producing the positive electrode active material layer, the mixed powder can be produced by applying a slurry obtained by mixing with a known solvent on a current collector.
  • a known material can be used as the negative electrode active material.
  • the potential at which lithium is inserted / desorbed is close to the deposition / dissolution potential of metallic lithium.
  • a typical example is natural or artificial graphite in the form of particles (scale-like, lump-like, fibrous, whisker-like, spherical, pulverized particles, etc.).
  • lithium transition metal oxide, lithium transition metal nitride, transition metal oxide, silicon oxide, and the like can be used as the negative electrode active material. Among these, graphite is preferable from the viewpoint of cycle.
  • artificial graphite examples include graphite obtained by graphitizing mesocarbon microbeads, mesophase pitch powder, isotropic pitch powder, and the like. Also, graphite particles having amorphous carbon attached to the surface can be used. Among these, natural graphite is more preferable because it is inexpensive, close to the redox potential of lithium, and can constitute a high energy density battery.
  • foamed (porous) metal having continuous pores, metal formed in a honeycomb shape, sintered metal, expanded metal, non-woven fabric, plate, foil, perforated plate, foil, and the like can be used.
  • the negative electrode current collector is usually made of copper.
  • (C) Separator As the separator, a porous material or a nonwoven fabric can be used singly or in combination. As a material for the separator, a material that does not dissolve or swell with respect to an organic solvent contained in the electrolyte described later is preferable. Specific examples include polyester polymers, polyolefin polymers (for example, polyethylene and polypropylene), ether polymers, aramid polymers, and inorganic materials such as glass.
  • Nonaqueous electrolyte A lithium ion secondary battery usually includes a nonaqueous electrolyte between a positive electrode and a negative electrode.
  • a nonaqueous electrolyte for example, an organic electrolyte, a gel electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte, a molten salt, or the like can be used.
  • organic electrolytes are generally used from the viewpoint of battery manufacturability.
  • the organic electrolyte contains an electrolyte salt and an organic solvent.
  • organic solvents include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), and butylene carbonate, chains such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dipropyl carbonate.
  • PC propylene carbonate
  • EC ethylene carbonate
  • BMC butylene carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • EMC ethyl methyl carbonate
  • dipropyl carbonate dipropyl carbonate
  • Examples of the electrolyte salt include lithium borofluoride (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium trifluoroacetate (LiCF 3 COO), lithium bis (trifluoro) Examples thereof include lithium salts such as (romethanesulfone) imide (LiN (CF 3 SO 2 ) 2 ), and one or more of these can be mixed and used.
  • the salt concentration of the electrolytic solution is preferably 0.5 to 3 mol / l.
  • Vinylene carbonate (VC), fluoroethylene carbonate, trifluoropropylene carbonate, phenylethylene carbonate, succinic anhydride, glutaric anhydride, maleic anhydride, ethylene sulfite, 1,3-propane sultone, 1,4-butane sultone, Dehydrating agents and deoxidizing agents such as methyl methanesulfonate, dibutyl sulfide, heptane, octane, and cycloheptane can be used.
  • the lithium ion secondary battery is provided with the laminated body which consists of a positive electrode, a negative electrode, and the separator pinched
  • the laminate may have, for example, a strip-like planar shape. Moreover, when producing a cylindrical or flat battery, the laminate may be wound.
  • One or more of the laminates are inserted into the battery container.
  • the positive electrode and the negative electrode are connected to the external conductive terminal of the battery. Thereafter, the battery container is sealed to block the positive electrode, the negative electrode, and the separator from the outside air.
  • the sealing method is generally a method in which a lid having a resin packing is fitted into the opening of the battery container and the battery container and the lid are caulked.
  • a method of attaching a lid called a metallic sealing plate to the opening and performing welding can be used.
  • a method of sealing with a binder and a method of fixing with a bolt via a gasket can also be used.
  • an opening for injecting the electrolyte may be provided at the time of sealing.
  • the lithium ion secondary battery 24 mainly includes (i) the positive electrode 11, the negative electrode 12, and the separator 19 positioned between the positive electrode 11 and the negative electrode 12.
  • a single cell 20 and (ii) aluminum laminate films 21 and 22 each having a heat welding portion 23 are provided.
  • the single cell 20 is located between the aluminum laminate films 21 and 22.
  • the lithium ion secondary battery 24 is manufactured by sandwiching the single cell 20 between the aluminum laminate films 21 and 22 and heat-welding the aluminum laminate films 21 and 22 at the heat fusion part 23.
  • the positive electrode 11 includes the positive electrode current collector 2 and the positive electrode active material including the phosphoric acid composite compound 1 and the second compound 3 formed on the positive electrode current collector 2 (FIG. 1). (See (b)).
  • a tab lead 14 with an adhesive film 13 is connected to the positive electrode 11, and a tab lead 16 with an adhesive film 15 is connected to the negative electrode 12.
  • the separator 19 is located between the coating surface 18 of the positive electrode 11 and the coating surface 17 of the negative electrode 12.
  • the material of the tab leads 4 and 6, the components of the electrolytic solution, and the like can be arbitrarily adjusted.
  • the positive electrode 11 and the negative electrode 12 are dried under reduced pressure at 130 ° C. for 24 hours, and then placed in a glow box in a dry Ar atmosphere.
  • an aluminum tab lead 14 with an adhesive film 13 is ultrasonically welded to the positive electrode 11, and a nickel tab lead 16 with an adhesive film 15 is ultrasonically welded to the negative electrode 12.
  • a polyethylene microporous film (size: 31 mm (length) ⁇ 31 mm (width), thickness 25 ⁇ m, porosity 55%) is loaded as a separator 19 so that the coated surface 17 of the negative electrode 12 is hidden. Furthermore, a laminate is obtained by stacking the positive electrode 11 on the separator 19 so that the coating surface 18 overlaps the center of the separator 19. Further, the laminate is sandwiched between the aluminum laminate films 21 and 22, and the three sides of the aluminum laminate films 21 and 22 are heat-welded so as to sandwich the adhesive films 13 and 15 of the tab leads 14 and 16.
  • an electrolyte solution in which LiPF 6 is dissolved is poured into a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2 so as to be 1 mol / l.
  • EC ethylene carbonate
  • DEC diethyl carbonate
  • the last side of the aluminum laminate bag is heat-sealed under a reduced pressure of 10 kPa, whereby a laminated lithium ion secondary battery (cell) 24 of the single cell 20 is obtained.
  • the injection amount of the electrolyte is appropriately determined according to the thickness of the positive electrode 11 and the negative electrode 12 used in the lithium ion secondary battery 24, and the amount of the electrolyte sufficiently penetrating into the positive electrode 11, the negative electrode 12, and the separator 19 And it is sufficient.
  • the positive electrode active material according to aspect 1 of the present invention is a positive electrode active material for a lithium ion secondary battery
  • the positive electrode active material is Li, M, Z, P, Si, and O (M is one or both of Fe and Mn, and Z is a group consisting of Co, Ni, Zr, Sn, Al, and Y).
  • a first compound (phosphate complex compound 1) which is a phosphate complex compound composed of at least one element selected or a combination thereof;
  • a second compound (3) comprising either one or both of an oxide and a phosphide,
  • the second compound is (I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element (Ii)
  • M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si.
  • the first compound and the second compound, as a mixture thereof, have the following general formula (1): Li a M b Z c P d Si e O f (1) (1.0 ⁇ a ⁇ 1.1, 0.75 ⁇ b ⁇ 0.99, 0 ⁇ c ⁇ 0.3, 0.5 ⁇ d ⁇ 1.1, 0 ⁇ e ⁇ 0.6, 3 ⁇ f ⁇ 5).
  • a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output can be provided.
  • the positive electrode active material according to the second aspect of the present invention is the first aspect.
  • the second compound may be included in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the first compound.
  • the positive electrode active for a lithium ion secondary battery that can be charged and discharged with higher input / output.
  • it is set as a positive electrode electronic conductivity is improved and the fall of the battery voltage at the time of high input / output can be suppressed.
  • the positive electrode active material according to the aspect 3 of the present invention is the aspect 1 or 2
  • the second compound may be selected from Li 3 PO 4 , ZrO 2 , SiO 2 , Zr 2 P and Zr 3 P.
  • the lithium ion secondary battery that can be charged and discharged with higher input / output
  • the positive electrode active material can be provided.
  • the positive electrode active material according to Aspect 4 of the present invention is any one of Aspects 1 to 3, A, b, c, d and e are 1.01 ⁇ a ⁇ 1.1, 0.875 ⁇ b ⁇ 0.99, 0 ⁇ c ⁇ 0.125, 0.75 ⁇ d ⁇ 1.05, It may be 0 ⁇ e ⁇ 0.25.
  • a, b, c, d, and e are 1.01 ⁇ a ⁇ 1.1, 0.875 ⁇ b ⁇ 0.99, 0 ⁇ c ⁇ 0.125, 0.75 ⁇ d.
  • a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with higher input / output can be provided.
  • the average particle diameter can be appropriately controlled during the production of the positive electrode active material, so that when the positive electrode is used, the density can be increased and the volume energy density of the battery can be improved.
  • the positive electrode active material according to Aspect 5 of the present invention is any one of Aspects 1 to 4, A, b, c, d and e are 1.01 ⁇ a ⁇ 1.05, 0.94 ⁇ b ⁇ 0.99, 0.01 ⁇ c ⁇ 0.06, 0.97 ⁇ d ⁇ 1. 02, 0.02 ⁇ e ⁇ 0.06.
  • a, b, c, d, and e are 1.01 ⁇ a ⁇ 1.05, 0.94 ⁇ b ⁇ 0.99, 0.01 ⁇ c ⁇ 0.06, 0.97.
  • a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with higher input / output can be provided. Further, in this composition range, the positive electrode active material can be produced by a cheaper manufacturing method, and the battery can be reduced in cost.
  • the second compound may be positioned on the surface of the positive electrode active material.
  • the area where the positive electrode active material and the electrolytic solution are in direct contact with each other is suppressed, electrochemical decomposition of the electrolytic solution on the positive electrode surface is suppressed, and deterioration of the battery capacity due to repeated repeated charging and discharging is suppressed. Less.
  • the decomposition reaction of the electrolytic solution is suppressed, and the self-discharge of the battery can be suppressed.
  • the reaction between the positive electrode active material and the electrolytic solution is suppressed even if the temperature inside the battery rises, thereby improving the safety of the battery. .
  • the shape of the second compound when the second compound is located on the surface of the positive electrode active material may be a shape that covers a part of the positive electrode active material, or over the entire positive electrode active material. The shape may be covered.
  • the coated second compound when the coated second compound is thick or completely coated, the diffusion of lithium is hindered, and when the battery is charged / discharged at a high rate, the capacity may be reduced. Therefore, for applications that require high output (for example, EV (Electric Vehicle), HEV (Hybrid Electric Vehicle), power tool use, etc.) that charge and discharge at 10C or higher, it may not be completely covered. preferable.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Al: P: Si has a molar ratio of 1.09: 0.95: 0.05: 0.98: 0.05
  • Each substance was weighed. These were mixed well in an agate mortar. This mixture was pulverized and mixed using a planetary ball mill.
  • the ball mill conditions were a rotation speed of 400 rpm, a rotation time of 1 hour, a ball made of zirconia having a diameter of 10 mm, and a mill pot made of zirconia. 15% by weight of sucrose with respect to the obtained powder was dissolved in an aqueous solution, and the obtained powder was mixed, mixed well in an agate mortar, and dried at 60 ° C.
  • the obtained powder was put into a quartz crucible and fired in a nitrogen atmosphere with a firing temperature of 550 ° C., a firing time of 12 hours, a temperature raising / lowering rate of 200 ° C./h, and a positive electrode active material having an average particle size of 22 ⁇ m was obtained.
  • the obtained positive electrode active material had an Li amount of 1.09, an Fe amount of 0.95, an Al amount of 0.05, a P amount of 0.98, and an Si amount of 0.05.
  • Li, Fe, Al, P, and Si are results obtained by a calibration curve method using an ICP mass spectrometer (ICP-MS 7500CS manufactured by Agilent Technologies), and values obtained by rounding down the third decimal place.
  • the average particle diameter is a value measured using a laser diffraction / scattering particle size distribution analyzer (LMS-2000e manufactured by Seishin Enterprise Co., Ltd.).
  • the coating was performed under the condition that the coating amount of the positive electrode active material was 8 mg / cm 2 .
  • the obtained coating film was dried in air at 100 ° C. for 30 minutes and pressed to provide a positive electrode having a 110 ⁇ m-thick positive electrode active material layer on the current collector (coating surface size: 28 mm (vertical) ⁇ 28 mm (horizontal)) was obtained.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, AlCl 3 .6H 2 O as an aluminum source, and (NH 4 ) as a phosphorus source. 2 HPO 4 , SiO 2 was used as the silicon source.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: Al: P: Si in a molar ratio of 1.00: 1.00: 0.03: 0.03: 0.97: 0.
  • the above substances were weighed so as to be 05. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.00, an Fe amount of 1.00, a Zr amount of 0.03, an Al amount of 0.03, a P amount of 0.97, and an Si amount of 0.05. It was.
  • the first compound is LiFe 0.97 Zr 0.02 Al 0.01 P 0.95 Si 0.05 O 4
  • the second compound is ZrO 2 , Al 2 O 3 , FePO 4 .
  • the second compound was contained in an amount of 4.3 parts by weight based on 100 parts by weight of the first compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and the molar ratio of Li: Fe: Zr: P: Si is 1.03: 0.99: 0.03: 1.01: 0.03
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.99, a Zr amount of 0.03, a P amount of 1.01, and an Si amount of 0.03.
  • the first compound is LiFe 0.99 Zr 0.01 P 0.97 Si 0.03 O 4
  • the second compound is ZrO 2 , Li 3 PO 4 , H 3 PO 4
  • the two compounds were contained in an amount of 2.8 parts by weight based on 100 parts by weight of the first compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.98: 0.04: 0.95: 0.06.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.98, a Zr amount of 0.04, a P amount of 0.95, and an Si amount of 0.06.
  • the first compound is LiFe 0.97 Zr 0.03 P 0.94 Si 0.06 O 4
  • the second compound is ZrO 2
  • the second compound is the first The amount was 1.5 parts by weight per 100 parts by weight of the compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.02: 0.98: 0.03: 0.97: 0.05.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.02, an Fe amount of 0.98, a Zr amount of 0.03, a P amount of 0.97, and an Si amount of 0.05.
  • the first compound is LiFe 0.97 Zr 0.03 P 0.95 Si 0.05 O 4
  • the second compound is Li 2 HPO 4 , H 3 PO 4
  • the second compound is The amount was 1.9 parts by weight with respect to 100 parts by weight of the first compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.98: 0.02: 0.99: 0.04.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.98, a Zr amount of 0.02, a P amount of 0.99, and an Si amount of 0.04.
  • the first compound is LiFe 0.98 Zr 0.02 P 0.97 Si 0.03 O 4
  • the second compound is Li 2 HPO 4 , SiO 2
  • the second compound is the first It was 2.3 parts by weight with respect to 100 parts by weight of the compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.99: 0.06: 1.01: 0.04
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.99, a Zr amount of 0.06, a P amount of 1.01, and an Si amount of 0.04.
  • the first compound is LiFe 0.98 Zr 0.02 P 0.96 Si 0.04 O 4
  • the second compound is Zr 2 P, Li 2 HPO 4
  • the second compound is the first compound.
  • the amount was 4.7 parts by weight per 100 parts by weight of one compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.00: 0.99: 0.17: 1.01: 0.04.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li content of 1.00, an Fe content of 0.99, a Zr content of 0.17, a P content of 1.01, and an Si content of 0.04.
  • the first compound is LiFe 0.98 Zr 0.02 P 0.96 Si 0.04 O 4
  • the second compound is Zr 3 P
  • the second compound is 100 parts by weight of the first compound. 9.6 parts by weight were included.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g, and the molar ratio of Li: Fe: Zr: P: Si is 1.03: 0.88: 0.14: 0.86: 0.25
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.88, a Zr amount of 0.14, a P amount of 0.86, and an Si amount of 0.25.
  • the first compound is LiFe 0.88 Zr 0.13 P 0.75 Si 0.25 O 4
  • the second compound is Zr 2 P, Li 3 PO 4 , H 3 PO 4
  • the second compound was contained in an amount of 7.5 parts by weight with respect to 100 parts by weight of the first compound.
  • the starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.75: 0.26: 0.51: 0.50.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.75, a Zr amount of 0.26, a P amount of 0.51, and an Si amount of 0.50.
  • the first compound is LiFe 0.75 Zr 0.25 P 0.5 Si 0.5 O 4
  • the second compound is ZrO 2
  • the second compound is the first It was contained 1.4 parts by weight with respect to 100 parts by weight of the compound.
  • the starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Mn: Zr: P: Si has a molar ratio of 1.02: 0.99: 0.02: 0.98: 0.03.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.02, an Mn amount of 0.99, a Zr amount of 0.02, a P amount of 0.98, and an Si amount of 0.03.
  • the first compound is LiMn 0.99 Zr 0.01 P 0.97 Si 0.03 O 4
  • the second compound is ZrO 2 , Li 2 O
  • the second compound is the first compound. 1.0 part by weight was contained with respect to 100 parts by weight.
  • the starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.00: 0.98: 0.05: 0.95: 0.05.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.00, an Mn amount of 0.98, a Zr amount of 0.05, a P amount of 0.95, and an Si amount of 0.05.
  • the first compound is LiMn 0.98 Zr 0.02 P 0.95 Si 0.05 O 4
  • the second compound is ZrO 2
  • the second compound is in 100 parts by weight of the first compound. In contrast, 1.6 parts by weight were contained.
  • the starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, SnCl 4 .5H 2 O as a tin source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. It was used.
  • the lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.00: 0.96: 0.05: 0.91: 0.09
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li content of 1.00, an Mn content of 0.96, an Sn content of 0.05, a P content of 0.91, and an Si content of 0.09.
  • the first compound is LiMn 0.95 Sn 0.05 P 0.91 Si 0.09 O 4
  • the second compound is SnO 2
  • the second compound is 100 parts by weight of the first compound. In contrast, 0.9 part by weight was contained.
  • the starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Mn: Zr: P: Si has a molar ratio of 1.02: 0.88: 0.13: 0.76: 0.24.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.02, an Mn amount of 0.88, a Zr amount of 0.13, a P amount of 0.76, and an Si amount of 0.24.
  • the first compound is LiMn 0.88 Zr 0.12 P 0.76 Si 0.24 O 4
  • the second compound is Li 2 O
  • the second compound first compound 100 parts by weight 0.2 part by weight was included.
  • the starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Mn: Zr: P: Si has a molar ratio of 1.03: 0.75: 0.26: 0.51: 0.50.
  • Each substance was weighed. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.03, an Mn amount of 0.75, a Zr amount of 0.26, a P amount of 0.51, and an Si amount of 0.50.
  • the first compound is LiMn 0.75 Zr 0.25 P 0.5 Si 0.5 O 4
  • the second compound is Li 3 PO 4
  • the second compound is 100 wt% of the first compound. 0.7 parts by weight with respect to parts.
  • Example 16 LiCH 3 COO as a lithium source as a starting material, FeC 2 O 4 .2H 2 O as an iron source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, and a phosphorus source (NH 4 ) 2 HPO 4 , SiO 2 was used as the silicon source.
  • the lithium source LiCH 3 COO is 0.6599 g
  • Li: Fe: Mn: Zr: P: Si is 1.04: 0.50: 0.49: 0.02: 0.98: 0.
  • the above substances were weighed so as to be 03. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.04, an Fe amount of 0.50, an Mn amount of 0.49, a Zr amount of 0.02, a P amount of 0.98, and an Si amount of 0.03. It was.
  • the first compound is LiFe 0.5 Mn 0.49 Zr 0.01 P 0.97 Si 0.03 O 4
  • the second compound is ZrO 2 , Li 2 O
  • the second compound Contained 1.2 parts by weight with respect to 100 parts by weight of the first compound.
  • Example 17 LiCH 3 COO as a lithium source as a starting material, FeC 2 O 4 .2H 2 O as an iron source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, and a phosphorus source (NH 4 ) 2 HPO 4 , SiO 2 was used as the silicon source.
  • LiCH 3 COO as a lithium source is 0.6599 g
  • Li: Fe: Mn: Zr: P: Si is 1.02: 0.48: 0.50: 0.05: 0.95: 0.
  • the above substances were weighed so as to be 05. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material had an Li amount of 1.02, an Fe amount of 0.48, an Mn amount of 0.50, a Zr amount of 0.05, a P amount of 0.95, and an Si amount of 0.05. It was.
  • the first compound is LiFe 0.48 Mn 0.5 Sn 0.03 P 0.95 Si 0.05 O 4
  • the second compound is SnO 2 , Li 2 O
  • the second compound Contained 3.0 parts by weight with respect to 100 parts by weight of the first compound.
  • the obtained positive electrode active material was LiFePO 4 having a Li amount of 1.00, an Fe amount of 1.00, and a P amount of 1.00.
  • LiCH 3 COO as a lithium source LiCH 3 COO as a lithium source
  • Mn (NO 3 ) 2 .6H 2 O as a manganese source
  • (NH 4 ) 2 HPO 4 as a phosphorus source
  • the above-mentioned substances were weighed so that LiCH 3 COO as a lithium source was 0.6599 g and Li: Mn: P was 1.00: 1.00: 1.00 in a molar ratio. These were mixed well in an agate mortar.
  • a positive electrode active material having an average particle size of 22 ⁇ m was obtained in the same manner as in Example 1 except that this mixture was used.
  • the obtained positive electrode active material was LiMnPO 4 having a Li amount of 1.00, a Mn amount of 1.00, and a P amount of 1.00.
  • Table 1 shows the compositions of the positive electrode active materials of Examples and Comparative Examples. Table 1 also shows the discharge capacity and rate characteristics at 0.1 C and 10 C measured below. Table 2 shows the types and ratios of the first compound and the second compound.
  • a battery for measuring discharge capacity was prepared as follows.
  • the counter electrode and the reference electrode of the positive electrode metallic lithium laminated on a current collector made of nickel mesh was prepared.
  • Aluminum tabs were provided for the positive electrode and nickel tabs were provided for the counter and reference electrodes, and each tab was connected to an external circuit via a stainless steel (SUS304) wire.
  • the positive electrode, the counter electrode, and the reference electrode were immersed in 1 mol / L of LiPF 6 and 1 mol / L of VC / EC + DMC + EMC (volume ratio 1: 1: 1) in a glass container to produce a battery.
  • the charging mode is CC-CV, the charging rate in the constant current region is 0.1 C, and after the battery potential reaches 3.6 V, the charging mode shifts to the constant voltage region, and the charging rate is 0 in that region. The battery was charged until it reached 0.01 C to obtain a charge capacity.
  • the discharge mode is CC, and discharge is performed at a discharge rate of 0.1 C.
  • the discharge is terminated to obtain a discharge capacity at 0.1 C. .
  • Rate characteristics were calculated by dividing the discharge capacity at 10C by the discharge capacity at 0.1C.
  • the positive electrode active materials of the examples were able to suppress a decrease in discharge capacity even under a high input / output condition with a charge / discharge rate of 10C, compared with a low input / output condition with a charge / discharge rate of 0.1C.
  • the rate characteristics of the examples are improved, and it can be seen that this improvement is due to the presence of the second compound.
  • the present invention can be widely applied to all positive electrode active materials included in lithium ion secondary batteries.
  • it can be applied to HEVs and EVs that require a long charge / discharge cycle life and high input / output characteristics.

Abstract

This positive electrode active material contains a phosphate composite compound (1) that is configured of Li, M, Z, P, Si and O and a second compound (3) that is composed of an oxide and/or a phosphide. The first compound and the second compound are represented, as a mixture, by LiaMbZcPdSieOf (wherein 1.0 ≤ a ≤ 1.1, 0.75 ≤ b ≤ 0.99, 0 < c ≤ 0.3, 0.5 ≤ d ≤ 1.1, 0 < e ≤ 0.6 and 3 ≤ f ≤ 5).

Description

正極活物質Cathode active material
　本発明は、正極活物質に関する。更に詳しくは、本発明は、高入出力で充放電可能なリチウムイオン二次電池を提供し得る正極活物質に関する。 The present invention relates to a positive electrode active material. More specifically, the present invention relates to a positive electrode active material that can provide a lithium ion secondary battery that can be charged and discharged with high input / output.
　二次電池は、ポータブル電子機器用の小型のものだけでなく、車載用や電力貯蔵用等の大容量の蓄電デバイスとして注目されている。中でも、リチウムイオン二次電池は、他の電池（例えば、鉛蓄電池、ニッケルカドミウム電池、ニッケル水素電池）に比べて、高い電池容量を有することから、蓄電デバイスとして期待され、一部実用化されている。 Secondary batteries are attracting attention as not only small batteries for portable electronic devices, but also large-capacity electricity storage devices for in-vehicle use and power storage. Among them, lithium ion secondary batteries have higher battery capacity than other batteries (for example, lead storage batteries, nickel cadmium batteries, nickel hydride batteries), and are expected to be used as power storage devices. Yes.
　リチウムイオン二次電池は、正極、セパレータ及び負極をこの順で備え、正極及び負極を構成する活物質層へのリチウムイオンの挿入脱離を利用する電池である。リチウムイオン二次電池の正極活物質としては、ＬｉＣｏＯ２がよく知られている。しかし、ＬｉＣｏＯ２は安全性が十分ではなく、かつＣｏが希少元素であるため安価なリチウムイオン二次電池を提供し難かった。そこで、近年、Ｃｏに代えてＦｅやＭｎを使用したリン酸複合化合物からなる正極活物質が報告されている（例えば、国際公開ＷＯ２０１０／１５０８８９号公報：特許文献１）。この特許文献１は、充放電容量の低下の抑制を課題としている。また、その実施例では、Ｌｉ２ＯとＭＯ（ＦｅＯ、ＭｎＯ、ＣｏＯ及び／又はＮｉＯ）とＰ２Ｏ５との溶融物を、グルコース、スクロースやアセチレンブラックと混合しつつ粉砕することで粉砕物を得、粉砕物を加熱することで正極活物質が得られている。 A lithium ion secondary battery is a battery that includes a positive electrode, a separator, and a negative electrode in this order, and uses insertion and desorption of lithium ions to and from an active material layer that constitutes the positive electrode and the negative electrode. LiCoO 2 is well known as a positive electrode active material for lithium ion secondary batteries. However, LiCoO 2 is not sufficiently safe, and since Co is a rare element, it has been difficult to provide an inexpensive lithium ion secondary battery. Thus, in recent years, a positive electrode active material made of a phosphoric acid composite compound using Fe or Mn instead of Co has been reported (for example, International Publication No. WO2010 / 150889: Patent Document 1). This patent document 1 makes it a subject to control the fall of charging / discharging capacity. In the example, the melted product of Li 2 O, MO (FeO, MnO, CoO and / or NiO) and P 2 O 5 is pulverized while being mixed with glucose, sucrose or acetylene black. And the pulverized product is heated to obtain a positive electrode active material.
国際公開ＷＯ２０１０／１５０８８９号公報International publication WO2010 / 150889
　ところで、特に、車載用のリチウムイオン二次電池では、高入出力で充放電可能とすることが重要な課題であり、そのような特性を有する電池の開発が求められているが、未だそのような電池は得られていない。そのため、高入出力で充放電可能なリチウムイオン二次電池用の正極活物質の提供が望まれている。 By the way, in particular, in an in-vehicle lithium ion secondary battery, it is an important issue to enable charging and discharging at high input / output, and development of a battery having such characteristics is required, but it still seems to be No battery has been obtained. Therefore, provision of the positive electrode active material for lithium ion secondary batteries which can be charged / discharged with high input / output is desired.
　本発明は、高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供することを課題とする。 An object of the present invention is to provide a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output.
　本発明の一態様に係る正極活物質は、リチウムイオン二次電池用の正極活物質であり、
　前記正極活物質が、Ｌｉ、Ｍ、Ｚ、Ｐ、Ｓｉ及びＯ（Ｍは、Ｆｅ及びＭｎのいずれか一方又は両方であり、ＺはＣｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ及びＹからなる群から選択される少なくとも１種の元素又はそれらの組み合わせである）から構成されるリン酸複合化合物である第一化合物と、
　酸化物及びリン化物のいずれか一方又は両方からなる第二化合物と
を含み、
　前記第二化合物が、
（ｉ）前記第一化合物中のＭが、Ｆｅである場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ及びＳｉから選択される元素の酸化物及びリン化物、並びにＺｒ、Ｓｎ、Ａｌ及びＹから選択される元素のリン化物から少なくとも１種選択され、
（ｉｉ）前記第一化合物中のＭが、Ｍｎを含む場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ、Ｙ及びＳｉから選択される元素の酸化物及びリン化物から少なくとも１種選択され、
　前記第一化合物と前記第二化合物が、それらの混合物として、下記一般式（１）：
ＬｉａＭｂＺｃＰｄＳｉｅＯｆ　　（１）
（１．０≦ａ≦１．１、０．７５≦ｂ≦０．９９、０＜ｃ≦０．３、０．５≦ｄ≦１．１、０＜ｅ≦０．６、３≦ｆ≦５である）で表される。 The positive electrode active material according to one embodiment of the present invention is a positive electrode active material for a lithium ion secondary battery,
The positive electrode active material is Li, M, Z, P, Si, and O (M is one or both of Fe and Mn, and Z is a group consisting of Co, Ni, Zr, Sn, Al, and Y). A first compound which is a phosphoric acid complex compound composed of at least one selected element or a combination thereof;
A second compound comprising either one or both of an oxide and a phosphide,
The second compound is
(I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element
(Ii) When M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si. Species selected,
The first compound and the second compound, as a mixture thereof, have the following general formula (1):
Li a M b Z c P d Si e O f (1)
(1.0 ≦ a ≦ 1.1, 0.75 ≦ b ≦ 0.99, 0 <c ≦ 0.3, 0.5 ≦ d ≦ 1.1, 0 <e ≦ 0.6, 3 ≦ f ≦ 5).
　本発明によれば、高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。 According to the present invention, a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output can be provided.
正極活物質におけるリチウムイオンの拡散経路を示す図であり、（ａ）は第一化合物の表面に第二化合物が配置されていない正極活物質の一例を示す図であり、（ｂ）は第一化合物の表面に第二化合物が配置されている、本実施形態に係る正極活物質の一例を示す図である。It is a figure which shows the diffusion path | route of the lithium ion in a positive electrode active material, (a) is a figure which shows an example of the positive electrode active material in which the 2nd compound is not arrange | positioned on the surface of a 1st compound, (b) is 1st It is a figure which shows an example of the positive electrode active material which concerns on this embodiment in which the 2nd compound is arrange | positioned on the surface of a compound. リチウムイオン二次電池の概略図であり、（ａ）は構成部材の概略図の一例、（ｂ）はリチウムイオン二次電池の全体概略図の一例を示す図である。It is the schematic of a lithium ion secondary battery, (a) is an example of the schematic diagram of a structural member, (b) is a figure which shows an example of the whole schematic diagram of a lithium ion secondary battery.
　本発明の発明者等は、上記課題の原因が、正極活物質を構成するリン酸複合化合物の界面の状態にあることを見い出した。具体的には、充放電時にリチウムイオンは、図１の（ａ）に示すように、リン酸複合化合物１内部から、リン酸複合化合物／電解質界面、リン酸複合化合物／リン酸複合化合物界面まで拡散する。図１の（ａ）中、２は正極集電体、矢印はリチウムイオン拡散経路を意味する。リチウムイオンは、それぞれの界面エネルギーより大きな駆動力を得ることで、界面を乗り越えて他のリン酸複合化合物もしくは電解質に拡散していく。高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供するには、これらの界面のリチウムイオンの拡散に伴う界面エネルギーを低減することが必要であることを発明者等は見い出した。 The inventors of the present invention have found that the cause of the above problem is the state of the interface of the phosphoric acid composite compound constituting the positive electrode active material. Specifically, as shown in FIG. 1A, lithium ions are charged and discharged from the inside of the phosphoric acid complex compound 1 to the phosphoric acid complex compound / electrolyte interface and the phosphoric acid complex compound / phosphoric acid compound compound interface. Spread. In FIG. 1A, 2 indicates a positive electrode current collector, and an arrow indicates a lithium ion diffusion path. Lithium ions obtain a driving force larger than their interfacial energy, so that they cross over the interface and diffuse into other phosphate complex compounds or electrolytes. In order to provide a positive electrode active material for a lithium ion secondary battery that can be charged and discharged at high input / output, the inventors have found that it is necessary to reduce the interfacial energy associated with the diffusion of lithium ions at these interfaces. I found it.
　そこで、本発明の発明者等は、検討の結果、図１の（ｂ）に示すように、リン酸複合化合物（第一化合物）１に加えて、リチウムイオンの導電性を有する化合物（第二化合物）３を存在させる（例えば、第一化合物の表面を第二化合物で修飾する）ことで、上記界面エネルギーを低減できることを見い出し、本発明に至った。 Therefore, as a result of the study, the inventors of the present invention, as shown in FIG. 1 (b), in addition to the phosphoric acid complex compound (first compound) 1, a compound having a lithium ion conductivity (second It was found that the interfacial energy can be reduced by the presence of (compound) 3 (for example, the surface of the first compound is modified with the second compound), leading to the present invention.
　以下、本発明について詳しく説明する。 Hereinafter, the present invention will be described in detail.
　（Ｉ）正極活物質
　本発明の正極活物質は、リン酸複合化合物である第一化合物と、第一化合物の構成元素の化合物から構成された第二化合物とを、それぞれ少なくとも１つずつ含む。 (I) Cathode Active Material The cathode active material of the present invention includes at least one each of a first compound that is a phosphoric acid complex compound and a second compound that is composed of a compound of a constituent element of the first compound.
　（ａ）第一化合物
　第一化合物は、Ｌｉ、Ｍ、Ｚ、Ｐ、Ｓｉ及びＯ（Ｍは、Ｆｅ及びＭｎのいずれか一方又は両方であり、ＺはＣｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ及びＹからなる群から選択される少なくとも１種の元素又はそれらの組み合わせである）から構成される。第一化合物は、単一化合物でも、複数の化合物の混合物でもよい。具体的な第一化合物としては：
Ｌｉ／Ｆｅ／Ｃｏ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｎｉ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｓｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ａｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｙ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｚｒ／Ｐ／Ａｌ／Ｏ；
Ｌｉ／Ｍｎ／Ｃｏ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｎｉ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｓｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ａｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｙ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｚｒ／Ｐ／Ａｌ／Ｏ；
Ｌｉ／ＦｅとＭｎ／Ｃｏ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｎｉ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｓｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ａｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｙ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｙ／Ｐ／Ａｌ／Ｏ；
Ｌｉ／Ｆｅ／ＣｏとＮｉ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＣｏとＺｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＣｏとＳｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＣｏとＡｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＣｏとＹ／Ｐ／Ｓｉ／Ｏ；
Ｌｉ／Ｆｅ／ＮｉとＺｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＮｉとＳｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＮｉとＡｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＮｉとＹ／Ｐ／Ｓｉ／Ｏ；
Ｌｉ／Ｆｅ／ＺｒとＳｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＺｒとＡｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＺｒとＹ／Ｐ／Ｓｉ／Ｏ；
Ｌｉ／Ｆｅ／ＳｎとＡｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＳｎとＹ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／ＡｌとＹ／Ｐ／Ｓｉ／Ｏ；
の元素を組み合わせたもの等が挙げられる。これらの中でも、Ｌｉ／Ｆｅ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｓｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ａｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｆｅ／Ｚｒ／Ｐ／Ａｌ／Ｏ、Ｌｉ／Ｍｎ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｓｎ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ａｌ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／Ｍｎ／Ｚｒ／Ｐ／Ａｌ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｚｒ／Ｐ／Ｓｉ／Ｏ、Ｌｉ／ＦｅとＭｎ／Ｓｎ／Ｐ／Ｓｉ／Ｏの元素を組み合わせたものがより高入出力で充放電可能であるという観点から好ましい。 (A) First compound The first compound is Li, M, Z, P, Si and O (M is one or both of Fe and Mn, Z is Co, Ni, Zr, Sn, Al and And at least one element selected from the group consisting of Y or a combination thereof. The first compound may be a single compound or a mixture of a plurality of compounds. Specific first compounds include:
Li / Fe / Co / P / Si / O, Li / Fe / Ni / P / Si / O, Li / Fe / Zr / P / Si / O, Li / Fe / Sn / P / Si / O, Li / Fe / Al / P / Si / O, Li / Fe / Y / P / Si / O, Li / Fe / Zr / P / Al / O;
Li / Mn / Co / P / Si / O, Li / Mn / Ni / P / Si / O, Li / Mn / Zr / P / Si / O, Li / Mn / Sn / P / Si / O, Li / Mn / Al / P / Si / O, Li / Mn / Y / P / Si / O, Li / Mn / Zr / P / Al / O;
Li / Fe and Mn / Co / P / Si / O, Li / Fe and Mn / Ni / P / Si / O, Li / Fe and Mn / Zr / P / Si / O, Li / Fe and Mn / Sn / P / Si / O, Li / Fe and Mn / Al / P / Si / O, Li / Fe and Mn / Y / P / Si / O, Li / Fe and Mn / Y / P / Al / O;
Li / Fe / Co and Ni / P / Si / O, Li / Fe / Co and Zr / P / Si / O, Li / Fe / Co and Sn / P / Si / O, Li / Fe / Co and Al / P / Si / O, Li / Fe / Co and Y / P / Si / O;
Li / Fe / Ni and Zr / P / Si / O, Li / Fe / Ni and Sn / P / Si / O, Li / Fe / Ni and Al / P / Si / O, Li / Fe / Ni and Y / P / Si / O;
Li / Fe / Zr and Sn / P / Si / O, Li / Fe / Zr and Al / P / Si / O, Li / Fe / Zr and Y / P / Si / O;
Li / Fe / Sn and Al / P / Si / O, Li / Fe / Sn and Y / P / Si / O, Li / Fe / Al and Y / P / Si / O;
Or a combination of these elements. Among these, Li / Fe / Zr / P / Si / O, Li / Fe / Sn / P / Si / O, Li / Fe / Al / P / Si / O, Li / Fe / Zr / P / Al / O, Li / Mn / Zr / P / Si / O, Li / Mn / Sn / P / Si / O, Li / Mn / Al / P / Si / O, Li / Mn / Zr / P / Al / O, A combination of Li / Fe and Mn / Zr / P / Si / O or a combination of Li / Fe and Mn / Sn / P / Si / O is preferable from the viewpoint of charge / discharge with higher input / output.
　（ｂ）第二化合物
　第二化合物は、酸化物及びリン化物のいずれか一方又は両方からなる。 (B) Second compound The second compound comprises one or both of an oxide and a phosphide.
　具体的には、第二化合物は、
（ｉ）前記第一化合物中のＭが、Ｆｅである場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ及びＳｉから選択される元素の酸化物及びリン化物、並びにＺｒ、Ｓｎ、Ａｌ及びＹから選択される元素のリン化物から少なくとも１種選択され、
（ｉｉ）前記第一化合物中のＭが、Ｍｎを含む場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ、Ｙ及びＳｉから選択される元素の酸化物及びリン化物から少なくとも１種選択される。 Specifically, the second compound is
(I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element
(Ii) When M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si. Species selected.
　（ｉ）の場合、Ｚｒ、Ｓｎ、Ａｌ及びＹから選択される元素の酸化物及びリン化物を更に含んでいてもよい。 (I) In the case of (i), an oxide and a phosphide of an element selected from Zr, Sn, Al and Y may further be included.
　第二化合物は、リチウムイオンの導電性を有している化合物であるため、第一化合物と電解質界面、第一化合物間の界面を拡散する際のリチウムイオンの界面エネルギーを低減できる。第二化合物は、単一化合物でも、複数の化合物の混合物でもよい。具体的な第二化合物としては、ＺｒＯ２、ＳｉＯ２、Ａｌ２Ｏ３、ＳｎＯ２等の酸化物、Ｌｉ３ＰＯ４、ＦｅＰＯ４、ＬｉＨ２ＰＯ４、Ｌｉ２ＨＰＯ４、Ｈ３ＰＯ４、Ｚｒ２Ｐ、Ｚｒ３Ｐ等のリン化合物が挙げられる。 Since the second compound is a compound having lithium ion conductivity, the interfacial energy of lithium ions when diffusing the interface between the first compound and the electrolyte and the first compound can be reduced. The second compound may be a single compound or a mixture of a plurality of compounds. Specific examples of the second compound include oxides such as ZrO 2 , SiO 2 , Al 2 O 3 and SnO 2 , Li 3 PO 4 , FePO 4 , LiH 2 PO 4 , Li 2 HPO 4 , H 3 PO 4 , Examples thereof include phosphorus compounds such as Zr 2 P and Zr 3 P.
　（ｃ）第一化合物と第二化合物の混合物
　上記混合物は、下記一般式（１）：
ＬｉａＭｂＺｃＰｄＳｉｅＯｆ　　（１）
（ａ、ｂ、ｃ、ｄ及びｅは、ＩＣＰ－ＭＳ（誘導結合プラズマ－質量分析）から求められた値であり、ａは１．０≦ａ≦１．１、ｂは０．７５≦ｂ≦０．９９、ｃは０＜ｃ≦０．３、ｄは０．５≦ｄ≦１．１、ｅは０＜ｅ≦０．６、ｆは３≦ｆ≦５である）で表すことができる。ａが１．０未満の場合、混合物中のＬｉ量が少なくなり、二次電池を組み立てた際に十分な容量を得られなくなることがある。ａが１．１より大きい場合、第一化合物にも第二化合物にも属さないＬｉ化合物（例えばＬｉ２Ｏ、ＬｉＯＨ等）が形成される。二次電池を組み立てる際の電極塗工時に、このようなＬｉ化合物が大量に存在すると塗料が強塩基性を示すため集電体（Ａｌ箔等）の表面が変質してしまうことがある。ｂが０．７５未満の場合、第一化合物内で価数変化を起こす金属量が少なくなり、二次電池の充電時に第一化合物から脱離させられるＬｉ量が少なくなるため十分な容量が得られなくなることがある。ｂが０．９９より大きい場合、第一化合物に対する第二化合物の割合が増加するため、充放電に寄与するＬｉ量が小さくなるため、二次電池を組み立てた際に十分な容量を得られなくなることがある。ｃが０の場合（Ｚを含まない場合）、得られた第一化合物の単位格子体積がＬｉの挿入脱離によって大きく変化し、二次電池の充放電を繰り返した際に著しく容量が低下することがある。ｃが０．３より大きい場合、第一化合物に必要以上に取り込まれ、Ｍの含有量（つまりｂの値）を低下させてしまうことがある。ｄが０．５未満の場合、第一化合物に対する第二化合物の割合が増加するため十分な容量が得られなくなることがある。ｄが１．１より大きい場合、第一化合物にも第二化合物にも属さないＨ３ＰＯ４が形成される。二次電池を組み立てる際の電極塗工時に、このようなＨ３ＰＯ４が大量に存在すると塗料が強酸性を示すため集電体（Ａｌ箔等）の表面が変質してしまうとなることがある。ｅが０の場合（Ｓｉを含まない場合）、得られた第一化合物の単位格子体積がＬｉの挿入脱離によって大きく変化し、二次電池の充放電を繰り返した際に著しく容量が低下することがある。ｅが０．６より大きい場合、第二化合物として大量のＳｉＯ２が、第一化合物表面に形成してしまい、第一化合物への電子の授受が著しく低下するため、二次電池を組み立てた際に十分な容量が得られなくなることがある。 (C) Mixture of first compound and second compound The above mixture has the following general formula (1):
Li a M b Z c P d Si e O f (1)
(A, b, c, d and e are values obtained from ICP-MS (inductively coupled plasma-mass spectrometry), where a is 1.0 ≦ a ≦ 1.1 and b is 0.75 ≦ b. ≦ 0.99, c is 0 <c ≦ 0.3, d is 0.5 ≦ d ≦ 1.1, e is 0 <e ≦ 0.6, and f is 3 ≦ f ≦ 5) Can do. When a is less than 1.0, the amount of Li in the mixture decreases, and a sufficient capacity may not be obtained when the secondary battery is assembled. When a is larger than 1.1, a Li compound (for example, Li 2 O, LiOH, etc.) that does not belong to the first compound or the second compound is formed. When a large amount of such a Li compound is present during electrode coating when assembling a secondary battery, the surface of the current collector (Al foil or the like) may be altered because the paint exhibits strong basicity. If b is less than 0.75, the amount of metal that causes a valence change in the first compound is reduced, and the amount of Li that is desorbed from the first compound during charging of the secondary battery is reduced, so that sufficient capacity is obtained. It may not be possible. When b is larger than 0.99, the ratio of the second compound to the first compound increases, so the amount of Li that contributes to charge / discharge decreases, so that a sufficient capacity cannot be obtained when the secondary battery is assembled. Sometimes. When c is 0 (when Z is not included), the unit cell volume of the obtained first compound is greatly changed by insertion and extraction of Li, and the capacity is remarkably reduced when the secondary battery is repeatedly charged and discharged. Sometimes. When c is larger than 0.3, it may be incorporated more than necessary into the first compound, and the content of M (that is, the value of b) may be reduced. When d is less than 0.5, the ratio of the second compound to the first compound increases, so that a sufficient capacity may not be obtained. When d is greater than 1.1, H 3 PO 4 is formed which does not belong to the first compound or the second compound. When a large amount of H 3 PO 4 is present at the time of electrode application when assembling a secondary battery, the surface of the current collector (such as Al foil) may be altered because the paint exhibits strong acidity. is there. When e is 0 (when Si is not included), the unit cell volume of the obtained first compound is greatly changed by the insertion / desorption of Li, and the capacity is remarkably reduced when the secondary battery is repeatedly charged and discharged. Sometimes. When e is larger than 0.6, a large amount of SiO 2 as the second compound is formed on the surface of the first compound, and the transfer of electrons to the first compound is significantly reduced. In some cases, a sufficient capacity cannot be obtained.
　なお、ｆは、酸素の価数を「－２」とし、第一化合物の結晶内の電荷補償を満たすように設定し得る値と、第二化合物の結晶内の電荷補償を満たすように設定し得る値の合計値である。 Note that f is set to satisfy the charge compensation in the crystal of the second compound and the value that can be set to satisfy the charge compensation in the crystal of the first compound, with the valence of oxygen being “−2”. This is the total value to be obtained.
　ａ、ｂ、ｃ、ｄ及びｅは、１．０１≦ａ≦１．１、０．８７５≦ｂ≦０．９９、０＜ｃ≦０．１２５、０．７５≦ｄ≦１．０５、０＜ｅ≦０．２５であることが好ましい。ａ、ｂ、ｃ、ｄ及びｅがこの範囲から外れると一般的な製法で正極活物質を製造する場合に、粒子の平均粒径が適切な範囲に制御できないことがある。また、ａ、ｂ、ｃ、ｄ及びｅは、１．０１≦ａ≦１．０５、０．９４≦ｂ≦０．９９、０．０１≦ｃ≦０．０６、０．９７≦ｄ≦１．０２、０．０２≦ｅ≦０．０６であることがより好ましい。ａ、ｂ、ｃ、ｄ及びｅがこの範囲から外れると固相法で正極活物質を製造する場合に、粒子の平均粒径が適切な範囲に制御できないことがある。 a, b, c, d and e are 1.01 ≦ a ≦ 1.1, 0.875 ≦ b ≦ 0.99, 0 <c ≦ 0.125, 0.75 ≦ d ≦ 1.05, 0 It is preferable that <e ≦ 0.25. If a, b, c, d and e are out of this range, the average particle size of the particles may not be controlled within an appropriate range when the positive electrode active material is produced by a general production method. A, b, c, d and e are 1.01 ≦ a ≦ 1.05, 0.94 ≦ b ≦ 0.99, 0.01 ≦ c ≦ 0.06, 0.97 ≦ d ≦ 1. 0.02, 0.02 ≦ e ≦ 0.06 is more preferable. If a, b, c, d and e are out of this range, the average particle size of the particles may not be controlled within an appropriate range when the positive electrode active material is produced by the solid phase method.
　混合物に占める第一化合物と第二化合物との割合は、第一化合物１００重量部に対して、第二化合物が０．１～１０重量部であることが好ましい。第二化合物の割合が０．１重量部未満の場合、リチウムイオンの界面エネルギーの低減が十分でないことがある。１０重量部より多い場合、混合物に占めるリチウム量が少なくなり、充放電容量が低下することがある。より好ましい第二化合物の割合は、１～５重量部である。第二化合物の割合が１重量部より少なくなると、正極にした場合に、導電材と集電体との物理的な接点がより多く必要となり、電子伝導性が不十分となることがある。第二化合物の割合が５重量部より少なくなると、正極活物質表面において余剰な第二化合物が増えることがあり、正極にした場合に、バインダがより多く必要となり、電子伝導性が不十分となることがある。 The proportion of the first compound and the second compound in the mixture is preferably 0.1 to 10 parts by weight of the second compound with respect to 100 parts by weight of the first compound. When the ratio of the second compound is less than 0.1 parts by weight, the reduction of the interfacial energy of lithium ions may not be sufficient. When the amount is more than 10 parts by weight, the amount of lithium in the mixture decreases, and the charge / discharge capacity may decrease. A more preferable ratio of the second compound is 1 to 5 parts by weight. If the ratio of the second compound is less than 1 part by weight, more physical contacts between the conductive material and the current collector are required when the positive electrode is used, and the electron conductivity may be insufficient. When the proportion of the second compound is less than 5 parts by weight, an excessive amount of the second compound may increase on the surface of the positive electrode active material, and in the case of the positive electrode, more binder is required and the electron conductivity becomes insufficient. Sometimes.
　ここで、混合物から第一化合物と第二化合物とが占める割合の算出は、以下のように行うことができる。 Here, the ratio of the first compound and the second compound from the mixture can be calculated as follows.
　まず、得られた第一化合物と第二化合物に対して、ＸＲＤ測定を行い結晶構造解析を行った結果から、第一化合物であるＬｉａＭｂＺｃＰｄＳｉｅＯｆの結晶構造以外に相当する回折ピークに対して定性分析を行うことで、第二化合物の同定を行うことができる。次に、同定を行った第二化合物に含まれない元素が、第一化合物であるＬｉａＭｂＺｃＰｄＳｉｅＯｆに全て含まれるものとし、かつ、第一化合物が電気的中立を保つものとし、第一化合物の元素組成比を決定することができる。最後にＩＣＰ－ＭＳ測定によって求められた第一化合物と第二化合物の各元素の定量結果から、第一化合物の元素を差し引いて、第二化合物の定量を行うことができる。 First, the first compound and the second compound obtained from results of crystal structure analysis performed XRD measurement, except the crystal structure of a first compound Li a M b Z c P d Si e O f The second compound can be identified by performing a qualitative analysis on the diffraction peak corresponding to. Next, an element that is not contained in the second compound was identified, it shall be all included in a first compound Li a M b Z c P d Si e O f, and the first compound is electrically neutral The elemental composition ratio of the first compound can be determined. Finally, the second compound can be quantified by subtracting the element of the first compound from the quantification result of each element of the first compound and the second compound obtained by ICP-MS measurement.
　また、第二化合物は、リチウムイオンの界面エネルギー低減の観点から、正極活物質の表面に位置していることが好ましい。表面に位置していることは、例えば、樹脂包埋しＦＩＢ加工によって得られた試料のＴＥＭ観察による格子像や電子線回折像により確認することができる。更に、正極活物質が、第一化合物と第二化合物の混合物を含む粒子の集合体である場合、図１の（ｂ）に示すように、個々の粒子の表面に第二化合物が位置していることが好ましい。粒子の平均粒径は、０．１～５００μｍであることが好ましい。０．１μｍより小さい、または５００μｍより大きくなると、正極の導電材粒子の粒径とのバランスが悪く、正極活物質粒子と導電材粒子との接点が少なくなる虞がある。さらに好ましくは１～５０μｍであり、この範囲であると、正極活物質に対して含ませる導電材の量が適量に制御しやすい。 The second compound is preferably located on the surface of the positive electrode active material from the viewpoint of reducing the interfacial energy of lithium ions. The position on the surface can be confirmed by, for example, a lattice image or an electron beam diffraction image obtained by TEM observation of a sample embedded in a resin and obtained by FIB processing. Furthermore, when the positive electrode active material is an aggregate of particles containing a mixture of the first compound and the second compound, the second compound is located on the surface of each particle as shown in FIG. Preferably it is. The average particle diameter of the particles is preferably 0.1 to 500 μm. If it is smaller than 0.1 μm or larger than 500 μm, the balance with the particle size of the conductive material particles of the positive electrode is poor, and there is a possibility that the contact between the positive electrode active material particles and the conductive material particles is reduced. More preferably, the thickness is 1 to 50 μm. If the thickness is within this range, the amount of the conductive material contained in the positive electrode active material can be easily controlled to an appropriate amount.
　（ｄ）リチウム含有金属酸化物の製造方法
　正極活物質は、原料として、各元素の炭酸塩、水酸化物、塩化物、硫酸塩、酢酸塩、酸化物、シュウ酸塩、硝酸塩、アルコキシド等の組合せを用いることにより製造できる。原料には水和水が含まれていてもよい。製造方法としては、焼成法、固相法、ゾルゲル法、溶融急冷法、メカノケミカル法、共沈法、水熱法、噴霧熱分解法等の方法を用いることができる。これら方法の内、不活性雰囲気（例えば、窒素雰囲気）下での焼成法（焼成条件は、４００～６５０℃で１～２４時間）が簡便である。 (D) Method for Producing Lithium-Containing Metal Oxide As a raw material, the positive electrode active material is a raw material such as carbonate, hydroxide, chloride, sulfate, acetate, oxide, oxalate, nitrate, alkoxide, etc. It can be manufactured by using a combination. The raw material may contain hydration water. As the production method, methods such as a firing method, a solid phase method, a sol-gel method, a melt quench method, a mechanochemical method, a coprecipitation method, a hydrothermal method, and a spray pyrolysis method can be used. Among these methods, a firing method under an inert atmosphere (for example, a nitrogen atmosphere) (firing conditions are 400 to 650 ° C. for 1 to 24 hours) is convenient.
　第二化合物の形成は、形成を望む第一化合物の構成に対応する原料に、形成を望む第二化合物の原料を加えて、上記方法で正極活物質を製造することにより行うことができる。 The formation of the second compound can be performed by adding the raw material of the second compound desired to be formed to the raw material corresponding to the configuration of the first compound desired to be formed, and producing the positive electrode active material by the above method.
　得られた正極活物質は、公知の粉砕法及びふるい分け法に付すことにより、所望の平均粒径に調整できる。 The obtained positive electrode active material can be adjusted to a desired average particle size by subjecting to a known pulverization method and sieving method.
　（ＩＩ）正極
　正極は、集電体（図１の（ｂ）中の正極集電体２）と、集電体上の正極活物質層とを備えている。 (II) Positive Electrode The positive electrode includes a current collector (positive electrode current collector 2 in FIG. 1B) and a positive electrode active material layer on the current collector.
　（ａ）正極活物質層
　正極活物質層は、上記正極活物質と、バインダとを含んでいることが好ましい。 (A) Positive electrode active material layer It is preferable that the positive electrode active material layer contains the said positive electrode active material and a binder.
　バインダとしては、（メタ）アクリル系樹脂、スチレンブタジエンゴム（ＳＢＲ）、ポリビニリデンフルオライド（ＰＶＤＦ）等が挙げられる。 Examples of the binder include (meth) acrylic resin, styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), and the like.
　バインダは、正極活物質１００重量部に対して、１～８重量部含みうる。バインダの含有量が１重量部より少ないと結着能力が不十分となることがあり、８重量部より多いと正極内に含まれる活物質量が減り、正極の抵抗又は分極等が大きくなって放電容量が小さくなることがある。 The binder may include 1 to 8 parts by weight with respect to 100 parts by weight of the positive electrode active material. When the binder content is less than 1 part by weight, the binding ability may be insufficient. When the binder content is more than 8 parts by weight, the amount of active material contained in the positive electrode decreases, and the resistance or polarization of the positive electrode increases. The discharge capacity may be reduced.
　また、バインダ以外に、導電材と増粘材とを含んでいてもよい。 In addition to the binder, a conductive material and a thickening material may be included.
　導電材としては、アセチレンブラック、カーボン、グラファイト、天然黒鉛、人造黒鉛、ニードルコークス等を用いることができる。 As the conductive material, acetylene black, carbon, graphite, natural graphite, artificial graphite, needle coke, or the like can be used.
　増粘材としては、カルボキシメチルセルロース、ポリビニルアルコール、ポリビニルピロリドン等を用いることができる。 As the thickener, carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be used.
　増粘材、導電材の含有量は、正極活物質１００重量部に対して、増粘材は０．５～５重量部程度、導電材は１～６重量部程度であることが好ましい。増粘材の含有量が、０．５重量部より少ないと増粘能力が不十分となることがあり、５重量部程度より多いと正極内に含まれる活物質量が減り、正極の抵抗又は分極等が大きくなって放電容量が小さくなることがある。導電材の含有量が１重量部より少ないと、正極の抵抗又は分極等が大きくなって放電容量が小さくなることがあり、６重量部程度より多いと正極内に含まれる活物質量が減ることにより正極としての放電容量が小さくなることがある。 The contents of the thickener and the conductive material are preferably about 0.5 to 5 parts by weight for the thickener and about 1 to 6 parts by weight for the conductive material with respect to 100 parts by weight of the positive electrode active material. If the content of the thickener is less than 0.5 parts by weight, the thickening ability may be insufficient. If it is more than about 5 parts by weight, the amount of the active material contained in the positive electrode decreases, and the positive electrode resistance or Polarization and the like may increase and the discharge capacity may decrease. If the content of the conductive material is less than 1 part by weight, the resistance or polarization of the positive electrode may increase and the discharge capacity may decrease, and if it exceeds about 6 parts by weight, the amount of active material contained in the positive electrode will decrease. As a result, the discharge capacity as the positive electrode may be reduced.
　正極活物質層の厚さは、０．０１～２ｍｍ程度が好ましい。厚すぎると導電性が低下し、薄すぎると単位面積当たりの容量が低下するので好ましくない。なお、塗布並びに乾燥によって得られた正極活物質層は、リチウム含有金属酸化物の充填密度を高めるためプレス処理に付してもよい。 The thickness of the positive electrode active material layer is preferably about 0.01 to 2 mm. If it is too thick, the conductivity is lowered, and if it is too thin, the capacity per unit area is lowered. Note that the positive electrode active material layer obtained by coating and drying may be subjected to press treatment in order to increase the packing density of the lithium-containing metal oxide.
　正極活物質層は、例えば、正極活物質とバインダとを、任意に増粘材及び導電材と共に、溶媒に混合したスラリーを集電体に塗布する等の公知の方法によって作製できる。 The positive electrode active material layer can be produced, for example, by a known method such as applying a slurry obtained by mixing a positive electrode active material and a binder, optionally together with a thickener and a conductive material, in a solvent to a current collector.
　溶媒には水や、Ｎ－メチル－２－ピロリドン、トルエン、シクロヘキサン、ジメチルホルムアミド、ジメチルアセトアミド、メチルエチルケトン、酢酸メチル、アクリル酸メチル、ジエチルトリアミン、Ｎ，Ｎ－ジメチルアミノプロピルアミン、エチレンオキシド、テトラヒドロフラン等の有機溶媒を用いることができる。 Solvents include water, N-methyl-2-pyrrolidone, toluene, cyclohexane, dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl acetate, methyl acrylate, diethyltriamine, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, etc. Organic solvents can be used.
　（ｂ）集電体
　集電体としては、連続孔を持つ発泡（多孔質）金属、ハニカム状に形成された金属、焼結金属、エキスパンドメタル、不織布、板、箔、孔開きの板、箔等を用いることができる。正極の集電体は、通常アルミニウムから構成される。 (B) Current collector As the current collector, foamed (porous) metal having continuous pores, metal formed in a honeycomb shape, sintered metal, expanded metal, non-woven fabric, plate, foil, perforated plate, foil Etc. can be used. The positive electrode current collector is usually made of aluminum.
　（ＩＩＩ）リチウムイオン二次電池
　リチウムイオン二次電池は、正極及び負極と、正極と負極との間に位置するセパレータとを備えている。本発明では、高入出力で充放電可能なリチウムイオン二次電池を得ることができるが、本明細書において、高出力とは、０．１Ｃで得られた容量に対する１０Ｃで得られた容量の割合（レート特性）を意味する。 (III) Lithium Ion Secondary Battery A lithium ion secondary battery includes a positive electrode and a negative electrode, and a separator positioned between the positive electrode and the negative electrode. In the present invention, a lithium ion secondary battery that can be charged / discharged at high input / output can be obtained. In this specification, high output is the capacity obtained at 10 C relative to the capacity obtained at 0.1 C. It means the ratio (rate characteristic).
　（ａ）正極
　正極には上記（ＩＩ）の正極を使用できる。 (A) Positive electrode The positive electrode of said (II) can be used for a positive electrode.
　（ｂ）負極
　負極は、集電体上に負極活物質層を備えたものを使用できる。 (B) Negative electrode A negative electrode having a negative electrode active material layer on a current collector can be used.
　負極活物質層は公知の方法により作製できる。具体的には、正極活物質層の作製法で説明した方法と同様にして作製できる。例えば、正極活物質層の欄で説明したバインダ（スチレンブタジエンゴム（ＳＢＲ）、ポリビニリデンフルオライド（ＰＶＤＦ）等）と導電材と増粘材とを、負極活物質と混合した後、この混合粉末をシート状に成形し、得られた成形体をステンレス、集電体に圧着することで負極活物質層を得ることができる。また、上記混合粉末を正極活物質層の作製法で説明したように、公知の溶媒と混合して得られたスラリーを集電体上に塗布することにより作製することもできる。 The negative electrode active material layer can be produced by a known method. Specifically, it can be produced in the same manner as described in the method for producing the positive electrode active material layer. For example, the binder (styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), etc.) described in the column of the positive electrode active material layer, a conductive material, and a thickener are mixed with the negative electrode active material, and then the mixed powder The negative electrode active material layer can be obtained by molding the molded body into a sheet shape and press-bonding the obtained molded body to stainless steel and a current collector. Further, as described in the method for producing the positive electrode active material layer, the mixed powder can be produced by applying a slurry obtained by mixing with a known solvent on a current collector.
　負極活物質としては公知の材料を用いることができる。高エネルギー密度電池を構成するためには、リチウムの挿入／脱離する電位が金属リチウムの析出／溶解電位に近いものが好ましい。その典型例は、粒子状（鱗片状、塊状、繊維状、ウィスカー状、球状、粉砕粒子状等）の天然もしくは人造黒鉛である。また、リチウム遷移金属酸化物、リチウム遷移金属窒化物、遷移金属酸化物、酸化シリコン等も負極活物質として使用可能である。この内、サイクルの観点から、黒鉛が好ましい。 A known material can be used as the negative electrode active material. In order to constitute a high energy density battery, it is preferable that the potential at which lithium is inserted / desorbed is close to the deposition / dissolution potential of metallic lithium. A typical example is natural or artificial graphite in the form of particles (scale-like, lump-like, fibrous, whisker-like, spherical, pulverized particles, etc.). Further, lithium transition metal oxide, lithium transition metal nitride, transition metal oxide, silicon oxide, and the like can be used as the negative electrode active material. Among these, graphite is preferable from the viewpoint of cycle.
　人造黒鉛としては、メソカーボンマイクロビーズ、メソフェーズピッチ粉末、等方性ピッチ粉末等を黒鉛化して得られる黒鉛が挙げられる。また、非晶質炭素を表面に付着させた黒鉛粒子も使用できる。これらの中で、天然黒鉛は、安価でかつリチウムの酸化還元電位に近く、高エネルギー密度電池が構成できるためより好ましい。 Examples of artificial graphite include graphite obtained by graphitizing mesocarbon microbeads, mesophase pitch powder, isotropic pitch powder, and the like. Also, graphite particles having amorphous carbon attached to the surface can be used. Among these, natural graphite is more preferable because it is inexpensive, close to the redox potential of lithium, and can constitute a high energy density battery.
　集電体としては、連続孔を持つ発泡（多孔質）金属、ハニカム状に形成された金属、焼結金属、エキスパンドメタル、不織布、板、箔、孔開きの板、箔等を用いることができる。負極の集電体は、通常銅から構成される。 As the current collector, foamed (porous) metal having continuous pores, metal formed in a honeycomb shape, sintered metal, expanded metal, non-woven fabric, plate, foil, perforated plate, foil, and the like can be used. . The negative electrode current collector is usually made of copper.
　（ｃ）セパレータ
　セパレータとしては、多孔質材料又は不織布等を単一もしくは複合で用いることができる。セパレータの材質としては、後述する、電解質中に含まれる有機溶媒に対して溶解したり膨潤したりしないものが好ましい。具体的には、ポリエステル系ポリマー、ポリオレフィン系ポリマー（例えば、ポリエチレン、ポリプロピレン）、エーテル系ポリマー、アラミド系ポリマー、ガラスのような無機材料等が挙げられる。 (C) Separator As the separator, a porous material or a nonwoven fabric can be used singly or in combination. As a material for the separator, a material that does not dissolve or swell with respect to an organic solvent contained in the electrolyte described later is preferable. Specific examples include polyester polymers, polyolefin polymers (for example, polyethylene and polypropylene), ether polymers, aramid polymers, and inorganic materials such as glass.
　（ｄ）非水電解質
　リチウムイオン二次電池は、通常、正極と負極間に非水電解質を備えている。非水電解質としては、例えば、有機電解液、ゲル状電解質、高分子固体電解質、無機固体電解質、溶融塩等を用いることができる。この内、有機電解液が、電池の製造容易性の観点から一般に使用されている。 (D) Nonaqueous electrolyte A lithium ion secondary battery usually includes a nonaqueous electrolyte between a positive electrode and a negative electrode. As the non-aqueous electrolyte, for example, an organic electrolyte, a gel electrolyte, a polymer solid electrolyte, an inorganic solid electrolyte, a molten salt, or the like can be used. Of these, organic electrolytes are generally used from the viewpoint of battery manufacturability.
　有機電解液は、電解質塩と有機溶媒とを含む。 The organic electrolyte contains an electrolyte salt and an organic solvent.
　有機溶媒としては、プロピレンカーボネート（ＰＣ）、エチレンカーボネート（ＥＣ）、ブチレンカーボネート等の環状カーボネート類、ジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、エチルメチルカーボネート（ＥＭＣ）、ジプロピルカーボネート等の鎖状カーボネート類、γ－ブチロラクトン（ＧＢＬ）、γ－バレロラクトン等のラクトン類、テトラヒドロフラン、２－メチルテトラヒドロフラン等のフラン類、ジエチルエーテル、１，２－ジメトキシエタン、１，２－ジエトキシエタン、エトキシメトキシエタン、ジオキサン等のエーテル類、ジメチルスルホキシド、スルホラン、メチルスルホラン、アセトニトリル、ギ酸メチル、酢酸メチル等が挙げられ、これらの１種以上を混合して用いることができる。 Examples of organic solvents include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), and butylene carbonate, chains such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dipropyl carbonate. Carbonates, lactones such as γ-butyrolactone (GBL) and γ-valerolactone, furans such as tetrahydrofuran and 2-methyltetrahydrofuran, diethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxy Examples thereof include ethers such as methoxyethane and dioxane, dimethyl sulfoxide, sulfolane, methyl sulfolane, acetonitrile, methyl formate, and methyl acetate. One or more of these can be used as a mixture.
　電解質塩としては、ホウフッ化リチウム（ＬｉＢＦ４）、六フッ化リン酸リチウム（ＬｉＰＦ６）、トリフルオロメタンスルホン酸リチウム（ＬｉＣＦ３ＳＯ３）、トリフルオロ酢酸リチウム（ＬｉＣＦ３ＣＯＯ）、リチウムビス（トリフルオロメタンスルホン）イミド（ＬｉＮ（ＣＦ３ＳＯ２）２）等のリチウム塩が挙げられ、これらの１種以上を混合して用いることができる。電解液の塩濃度は、０．５～３ｍｏｌ／ｌが好適である。 Examples of the electrolyte salt include lithium borofluoride (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium trifluoroacetate (LiCF 3 COO), lithium bis (trifluoro) Examples thereof include lithium salts such as (romethanesulfone) imide (LiN (CF 3 SO 2 ) 2 ), and one or more of these can be mixed and used. The salt concentration of the electrolytic solution is preferably 0.5 to 3 mol / l.
　また、ビニレンカーボネート（ＶＣ）、フルオロエチレンカーボネート、トリフルオロプロピレンカーボネート、フェニルエチレンカーボネート、無水コハク酸、無水グルタル酸、無水マレイン酸、エチレンサルファイト、１，３－プロパンスルトン、１，４－ブタンスルトン、メタンスルホン酸メチル、ジブチルスルフィド、ヘプタン、オクタン、シクロヘプタン等の脱水剤及び脱酸剤を使用できる。 Vinylene carbonate (VC), fluoroethylene carbonate, trifluoropropylene carbonate, phenylethylene carbonate, succinic anhydride, glutaric anhydride, maleic anhydride, ethylene sulfite, 1,3-propane sultone, 1,4-butane sultone, Dehydrating agents and deoxidizing agents such as methyl methanesulfonate, dibutyl sulfide, heptane, octane, and cycloheptane can be used.
　（ｅ）他の部材
　電池容器のような他の部材についても従来公知のリチウムイオン二次電池に使用される各種材料を使用でき、特に制限はない。 (E) Other members Various materials used for conventionally known lithium ion secondary batteries can be used for other members such as battery containers, and there is no particular limitation.
　（ｆ）リチウムイオン二次電池の製造方法
　リチウムイオン二次電池は、例えば、正極と負極と、それらの間に挟まれたセパレータとからなる積層体を備えている。積層体は、例えば短冊状の平面形状を有していてもよい。また、円筒型や扁平型の電池を作製する場合は、積層体を巻き取ってもよい。 (F) Manufacturing method of lithium ion secondary battery The lithium ion secondary battery is provided with the laminated body which consists of a positive electrode, a negative electrode, and the separator pinched | interposed between them, for example. The laminate may have, for example, a strip-like planar shape. Moreover, when producing a cylindrical or flat battery, the laminate may be wound.
　積層体は、その１つ又は複数が電池容器の内部に挿入される。通常、正極及び負極は電池の外部導電端子に接続される。その後に、正極、負極及びセパレータを外気より遮断するために電池容器を密閉する。 One or more of the laminates are inserted into the battery container. Usually, the positive electrode and the negative electrode are connected to the external conductive terminal of the battery. Thereafter, the battery container is sealed to block the positive electrode, the negative electrode, and the separator from the outside air.
　密封の方法は、円筒電池の場合、電池容器の開口部に樹脂製のパッキンを有する蓋をはめ込み、電池容器と蓋とをかしめる方法が一般的である。また、角型電池の場合、金属性の封口板と呼ばれる蓋を開口部に取りつけ、溶接を行う方法を使用できる。これらの方法以外に、結着剤で密封する方法、ガスケットを介してボルトで固定する方法も使用できる。 In the case of a cylindrical battery, the sealing method is generally a method in which a lid having a resin packing is fitted into the opening of the battery container and the battery container and the lid are caulked. In the case of a square battery, a method of attaching a lid called a metallic sealing plate to the opening and performing welding can be used. In addition to these methods, a method of sealing with a binder and a method of fixing with a bolt via a gasket can also be used.
　更に、金属箔に熱可塑性樹脂を貼り付けたラミネート膜で密封する方法も使用できる。 Furthermore, a method of sealing with a laminate film in which a thermoplastic resin is attached to a metal foil can also be used.
　なお、密封時に電解質注入用の開口部を設けてもよい。 Note that an opening for injecting the electrolyte may be provided at the time of sealing.
　ここで、図２に基づいて、リチウムイオン二次電池２４の構成と具体的な製造例とについて説明する。 Here, the configuration of the lithium ion secondary battery 24 and a specific manufacturing example will be described with reference to FIG.
　図２（ａ）および（ｂ）に示すように、リチウムイオン二次電池２４は、主として、（i）正極１１、負極１２、および、正極１１と負極１２との間に位置するセパレータ１９を備える単セル２０と、（ii）熱溶着部２３を有するアルミラミネートフィルム２１及び２２とを備える。単セル２０は、アルミラミネートフィルム２１及び２２の間に位置している。アルミラミネートフィルム２１及び２２間に単セル２０を挟み、熱融着部２３においてアルミラミネートフィルム２１及び２２を熱溶着することにより、リチウムイオン二次電池２４が製造される。 2A and 2B, the lithium ion secondary battery 24 mainly includes (i) the positive electrode 11, the negative electrode 12, and the separator 19 positioned between the positive electrode 11 and the negative electrode 12. A single cell 20 and (ii) aluminum laminate films 21 and 22 each having a heat welding portion 23 are provided. The single cell 20 is located between the aluminum laminate films 21 and 22. The lithium ion secondary battery 24 is manufactured by sandwiching the single cell 20 between the aluminum laminate films 21 and 22 and heat-welding the aluminum laminate films 21 and 22 at the heat fusion part 23.
　正極１１は、上述のように、正極集電体２と、正極集電体２上に形成された、リン酸複合化合物１および第二化合物３を含む正極活物質とを備えている（図１の（ｂ）参照）。また、正極１１には、接着フィルム１３付きのタブリード１４が接続されており、負極１２には、接着フィルム１５付きのタブリード１６が接続されている。セパレータ１９は、正極１１の塗工面１８と、負極１２の塗工面１７との間に位置している。 As described above, the positive electrode 11 includes the positive electrode current collector 2 and the positive electrode active material including the phosphoric acid composite compound 1 and the second compound 3 formed on the positive electrode current collector 2 (FIG. 1). (See (b)). A tab lead 14 with an adhesive film 13 is connected to the positive electrode 11, and a tab lead 16 with an adhesive film 15 is connected to the negative electrode 12. The separator 19 is located between the coating surface 18 of the positive electrode 11 and the coating surface 17 of the negative electrode 12.
　より具体的には、以下のように製造される。なお、この製造例はあくまで一例であって、例えば各種数値、タブリード４および６の材質、電解液の成分等は任意に調整可能である。正極１１及び負極１２を１３０℃で２４時間減圧乾燥した後に、ドライＡｒ雰囲気下のグローボックス内に入れる。次いで、正極１１に接着フィルム１３付きのアルミニウム製タブリード１４を、負極１２に接着フィルム１５付きのニッケル製のタブリード１６をそれぞれ超音波溶接する。グローボックス内で、負極１２の塗工面１７が隠れるようにセパレータ１９としてポリエチレンの微多孔膜（サイズ：３１ｍｍ（縦）×３１ｍｍ（横）、厚さ２５μｍ、空隙率５５％）を積載する。更に、セパレータ１９上から、塗工面１８がセパレータ１９の中心に重なるように正極１１を重ねることで積層体を得る。更に、アルミラミネートフィルム２１及び２２で積層体をはさみ、タブリード１４及び１６の接着フィルム１３及び１５を挟むようにアルミラミネートフィルム２１及び２２の３辺を熱溶着する。未溶着の１辺から、エチレンカーボネート（ＥＣ）とジエチルカーボネート（ＤＥＣ）を体積比１：２で混合した溶媒に１ｍｏｌ／ｌになるようにＬｉＰＦ６を溶解させた電解液を注液する。注液後、アルミラミネート袋の最後の１辺を１０ｋＰａの減圧下で熱融着することで、単セル２０のラミネート型のリチウムイオン二次電池（セル）２４が得られる。電解液の注液量は、リチウムイオン二次電池２４で使用する正極１１及び負極１２の厚さに準じて適宜決定しており、正極１１、負極１２及びセパレータ１９に電解液が十分浸透する量とすればよい。 More specifically, it is manufactured as follows. Note that this manufacturing example is merely an example, and various numerical values, the material of the tab leads 4 and 6, the components of the electrolytic solution, and the like can be arbitrarily adjusted. The positive electrode 11 and the negative electrode 12 are dried under reduced pressure at 130 ° C. for 24 hours, and then placed in a glow box in a dry Ar atmosphere. Next, an aluminum tab lead 14 with an adhesive film 13 is ultrasonically welded to the positive electrode 11, and a nickel tab lead 16 with an adhesive film 15 is ultrasonically welded to the negative electrode 12. In the glow box, a polyethylene microporous film (size: 31 mm (length) × 31 mm (width), thickness 25 μm, porosity 55%) is loaded as a separator 19 so that the coated surface 17 of the negative electrode 12 is hidden. Furthermore, a laminate is obtained by stacking the positive electrode 11 on the separator 19 so that the coating surface 18 overlaps the center of the separator 19. Further, the laminate is sandwiched between the aluminum laminate films 21 and 22, and the three sides of the aluminum laminate films 21 and 22 are heat-welded so as to sandwich the adhesive films 13 and 15 of the tab leads 14 and 16. From one side of the unwelded, an electrolyte solution in which LiPF 6 is dissolved is poured into a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 1: 2 so as to be 1 mol / l. After the injection, the last side of the aluminum laminate bag is heat-sealed under a reduced pressure of 10 kPa, whereby a laminated lithium ion secondary battery (cell) 24 of the single cell 20 is obtained. The injection amount of the electrolyte is appropriately determined according to the thickness of the positive electrode 11 and the negative electrode 12 used in the lithium ion secondary battery 24, and the amount of the electrolyte sufficiently penetrating into the positive electrode 11, the negative electrode 12, and the separator 19 And it is sufficient.
　〔まとめ〕
　本発明の態様１に係る正極活物質は、リチウムイオン二次電池用の正極活物質であり、
　前記正極活物質が、Ｌｉ、Ｍ、Ｚ、Ｐ、Ｓｉ及びＯ（Ｍは、Ｆｅ及びＭｎのいずれか一方又は両方であり、ＺはＣｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ及びＹからなる群から選択される少なくとも１種の元素又はそれらの組み合わせである）から構成されるリン酸複合化合物である第一化合物（リン酸複合化合物１）と、
　酸化物及びリン化物のいずれか一方又は両方からなる第二化合物（３）と
を含み、
　前記第二化合物が、
（ｉ）前記第一化合物中のＭが、Ｆｅである場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ及びＳｉから選択される元素の酸化物及びリン化物、並びにＺｒ、Ｓｎ、Ａｌ及びＹから選択される元素のリン化物から少なくとも１種選択され、
（ｉｉ）前記第一化合物中のＭが、Ｍｎを含む場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ、Ｙ及びＳｉから選択される元素の酸化物及びリン化物から少なくとも１種選択され、
　前記第一化合物と前記第二化合物が、それらの混合物として、下記一般式（１）：
ＬｉａＭｂＺｃＰｄＳｉｅＯｆ　　（１）
（１．０≦ａ≦１．１、０．７５≦ｂ≦０．９９、０＜ｃ≦０．３、０．５≦ｄ≦１．１、０＜ｅ≦０．６、３≦ｆ≦５である）で表される。 [Summary]
The positive electrode active material according to aspect 1 of the present invention is a positive electrode active material for a lithium ion secondary battery,
The positive electrode active material is Li, M, Z, P, Si, and O (M is one or both of Fe and Mn, and Z is a group consisting of Co, Ni, Zr, Sn, Al, and Y). A first compound (phosphate complex compound 1) which is a phosphate complex compound composed of at least one element selected or a combination thereof;
A second compound (3) comprising either one or both of an oxide and a phosphide,
The second compound is
(I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element
(Ii) When M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si. Species selected,
The first compound and the second compound, as a mixture thereof, have the following general formula (1):
Li a M b Z c P d Si e O f (1)
(1.0 ≦ a ≦ 1.1, 0.75 ≦ b ≦ 0.99, 0 <c ≦ 0.3, 0.5 ≦ d ≦ 1.1, 0 <e ≦ 0.6, 3 ≦ f ≦ 5).
　上記構成によれば、高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。 According to the above configuration, a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with high input / output can be provided.
　さらに、本発明の態様２に係る正極活物質は、態様１において、
　前記第二化合物が、前記第一化合物１００重量部に対して、０．１～１０重量部含まれてもよい。 Furthermore, the positive electrode active material according to the second aspect of the present invention is the first aspect.
The second compound may be included in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the first compound.
　上記構成によれば、第二化合物が、第一化合物１００重量部に対して、０．１～１０重量部含まれる場合、より高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。また、正極にした場合に電子伝導性が向上され、高入出力時の電池電圧の低下を抑制できる。 According to the above configuration, when the second compound is contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the first compound, the positive electrode active for a lithium ion secondary battery that can be charged and discharged with higher input / output. Can provide material. Moreover, when it is set as a positive electrode, electronic conductivity is improved and the fall of the battery voltage at the time of high input / output can be suppressed.
　さらに、本発明の態様３に係る正極活物質は、態様１または２において、
　前記第二化合物が、Ｌｉ３ＰＯ４、ＺｒＯ２、ＳｉＯ２、Ｚｒ２Ｐ及びＺｒ３Ｐから選択されてもよい。 Furthermore, the positive electrode active material according to the aspect 3 of the present invention is the aspect 1 or 2,
The second compound may be selected from Li 3 PO 4 , ZrO 2 , SiO 2 , Zr 2 P and Zr 3 P.
　上記構成によれば、第二化合物が、Ｌｉ３ＰＯ４、ＺｒＯ２、ＳｉＯ２、Ｚｒ２Ｐ及びＺｒ３Ｐから選択される場合、より高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。 According to the above configuration, when the second compound is selected from Li 3 PO 4 , ZrO 2 , SiO 2 , Zr 2 P, and Zr 3 P, the lithium ion secondary battery that can be charged and discharged with higher input / output The positive electrode active material can be provided.
　さらに、本発明の態様４に係る正極活物質は、態様１～３のいずれか１つにおいて、
　前記ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．１、０．８７５≦ｂ≦０．９９、０＜ｃ≦０．１２５、０．７５≦ｄ≦１．０５、０＜ｅ≦０．２５であってもよい。 Furthermore, the positive electrode active material according to Aspect 4 of the present invention is any one of Aspects 1 to 3,
A, b, c, d and e are 1.01 ≦ a ≦ 1.1, 0.875 ≦ b ≦ 0.99, 0 <c ≦ 0.125, 0.75 ≦ d ≦ 1.05, It may be 0 <e ≦ 0.25.
　上記構成によれば、ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．１、０．８７５≦ｂ≦０．９９、０＜ｃ≦０．１２５、０．７５≦ｄ≦１．０５、０＜ｅ≦０．２５である場合、より高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。また、この組成範囲では正極活物質製造時に平均粒径が適切に制御できるため、正極にした場合に高密度化でき、電池の体積エネルギー密度が向上できる。 According to the above configuration, a, b, c, d, and e are 1.01 ≦ a ≦ 1.1, 0.875 ≦ b ≦ 0.99, 0 <c ≦ 0.125, 0.75 ≦ d. When ≦ 1.05 and 0 <e ≦ 0.25, a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with higher input / output can be provided. Further, in this composition range, the average particle diameter can be appropriately controlled during the production of the positive electrode active material, so that when the positive electrode is used, the density can be increased and the volume energy density of the battery can be improved.
　さらに、本発明の態様５に係る正極活物質は、態様１～４のいずれか１つにおいて、
　前記ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．０５、０．９４≦ｂ≦０．９９、０．０１≦ｃ≦０．０６、０．９７≦ｄ≦１．０２、０．０２≦ｅ≦０．０６であってもよい。 Furthermore, the positive electrode active material according to Aspect 5 of the present invention is any one of Aspects 1 to 4,
A, b, c, d and e are 1.01 ≦ a ≦ 1.05, 0.94 ≦ b ≦ 0.99, 0.01 ≦ c ≦ 0.06, 0.97 ≦ d ≦ 1. 02, 0.02 ≦ e ≦ 0.06.
　上記構成によれば、ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．０５、０．９４≦ｂ≦０．９９、０．０１≦ｃ≦０．０６、０．９７≦ｄ≦１．０２、０．０２≦ｅ≦０．０６である場合、より高入出力で充放電可能なリチウムイオン二次電池用の正極活物質を提供できる。また、この組成範囲では正極活物質をより安価な製法で製造でき、電池を低コスト化できる。 According to the above configuration, a, b, c, d, and e are 1.01 ≦ a ≦ 1.05, 0.94 ≦ b ≦ 0.99, 0.01 ≦ c ≦ 0.06, 0.97. When ≦ d ≦ 1.02 and 0.02 ≦ e ≦ 0.06, a positive electrode active material for a lithium ion secondary battery that can be charged and discharged with higher input / output can be provided. Further, in this composition range, the positive electrode active material can be produced by a cheaper manufacturing method, and the battery can be reduced in cost.
　さらに、第二化合物が正極活物質の表面に位置している構成であってもよい。この場合、正極活物質と電解液とが直接接触する面積が抑制されるため、正極表面上での電解液の電気化学的な分解が抑制され、通常の充放電の繰り返しによる電池容量の劣化が少なくなる。または、充電状態で電池が長時間保管された場合に、電解液の分解反応が抑制され、電池の自己放電が抑制できる。さらには、電池が過充電状態または内部短絡状態になった場合に、電池内部の温度が上昇しても正極活物質と電解液との反応が抑制され、電池の安全性が向上する効果がある。 Further, the second compound may be positioned on the surface of the positive electrode active material. In this case, since the area where the positive electrode active material and the electrolytic solution are in direct contact with each other is suppressed, electrochemical decomposition of the electrolytic solution on the positive electrode surface is suppressed, and deterioration of the battery capacity due to repeated repeated charging and discharging is suppressed. Less. Alternatively, when the battery is stored for a long time in the charged state, the decomposition reaction of the electrolytic solution is suppressed, and the self-discharge of the battery can be suppressed. Furthermore, when the battery is in an overcharged state or an internal short circuit state, the reaction between the positive electrode active material and the electrolytic solution is suppressed even if the temperature inside the battery rises, thereby improving the safety of the battery. .
　さらに、第二化合物が正極活物質の表面に位置するときの当該第二化合物の形状は、正極活物質の一部を被覆するような形状となっていても良いし、正極活物質の全体にわたって被覆するような形状となっていても良い。なお、被覆した第二化合物の厚さが厚い、または完全に被覆されていると、リチウムの拡散が阻害されて、高率で電池の充放電を行う場合、容量が低下する虞がある。そのため、高出力が要求される用途（例えば、１０Ｃ以上で充放電を行うＥＶ（Electric Vehicle）、ＨＥＶ（Hybrid Electric Vehicle）や電動工具用途など）に対しては、完全に被覆されていないことが好ましい。 Furthermore, the shape of the second compound when the second compound is located on the surface of the positive electrode active material may be a shape that covers a part of the positive electrode active material, or over the entire positive electrode active material. The shape may be covered. In addition, when the coated second compound is thick or completely coated, the diffusion of lithium is hindered, and when the battery is charged / discharged at a high rate, the capacity may be reduced. Therefore, for applications that require high output (for example, EV (Electric Vehicle), HEV (Hybrid Electric Vehicle), power tool use, etc.) that charge and discharge at 10C or higher, it may not be completely covered. preferable.
　以下、実施例に基づいて本発明をより詳細に説明するが、本発明は以下の実施例に限定されるものではない。なお、実施例で使用した試薬等は、特に断りのない限りキシダ化学社製の特級試薬を用いた。 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples. The reagents used in the examples were special grade reagents manufactured by Kishida Chemical Co. unless otherwise specified.
　＜実施例１＞
　（正極活物質の合成）
　　（１）正極活物質
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、アルミニウム源としてＡｌＣｌ３・６Ｈ２Ｏ、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ａｌ：Ｐ：Ｓｉがモル比で１．０９：０．９５：０．０５：０．９８：０．０５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を遊星式のボールミルを用いて粉砕・混合した。ボールミル条件は回転速度４００ｒｐｍ、回転時間１時間、ボールは直径１０ｍｍのジルコニア製ボールを用い、またミルポットもジルコニア製ポットを用いた。得られた粉末に対して１５重量％のスクロースを水溶液に溶解させ、その溶液に得られた粉末を混合し、メノウ乳鉢でよく混合し、６０℃で乾燥させた。 <Example 1>
(Synthesis of positive electrode active material)
(1) Positive electrode active material LiCH 3 COO as a lithium source as a starting material, FeC 2 O 4 · 2H 2 O as an iron source, AlCl 3 · 6H 2 O as an aluminum source, (NH 4 ) 2 HPO 4 as a phosphorus source, silicon SiO 2 was used as the source. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Al: P: Si has a molar ratio of 1.09: 0.95: 0.05: 0.98: 0.05 Each substance was weighed. These were mixed well in an agate mortar. This mixture was pulverized and mixed using a planetary ball mill. The ball mill conditions were a rotation speed of 400 rpm, a rotation time of 1 hour, a ball made of zirconia having a diameter of 10 mm, and a mill pot made of zirconia. 15% by weight of sucrose with respect to the obtained powder was dissolved in an aqueous solution, and the obtained powder was mixed, mixed well in an agate mortar, and dried at 60 ° C.
　得られた粉末を石英製るつぼに入れ、焼成温度５５０℃、焼成時間１２時間、昇降温速度２００℃／ｈ、窒素雰囲気下で焼成することで、平均粒径２２μｍの正極活物質を得た。 The obtained powder was put into a quartz crucible and fired in a nitrogen atmosphere with a firing temperature of 550 ° C., a firing time of 12 hours, a temperature raising / lowering rate of 200 ° C./h, and a positive electrode active material having an average particle size of 22 μm was obtained.
　得られた正極活物質のＬｉ量は１．０９、Ｆｅ量は０．９５、Ａｌ量は０．０５、Ｐ量は０．９８、Ｓｉ量は０．０５であった。Ｌｉ、Ｆｅ、Ａｌ、Ｐ、ＳｉはＩＣＰ質量分析装置（Ａｇｉｌｅｎｔ　Ｔｅｃｈｎｏｌｏｇｉｅｓ社製ＩＣＰ－ＭＳ　７５００ＣＳ）を用い、検量線法により得られた結果であり、小数点第三位以下を切り捨てた値とした。平均粒径は、レーザー回折・散乱式粒度分布測定装置（セイシン企業社製ＬＭＳ－２０００ｅ）を用いて測定された値である。 The obtained positive electrode active material had an Li amount of 1.09, an Fe amount of 0.95, an Al amount of 0.05, a P amount of 0.98, and an Si amount of 0.05. Li, Fe, Al, P, and Si are results obtained by a calibration curve method using an ICP mass spectrometer (ICP-MS 7500CS manufactured by Agilent Technologies), and values obtained by rounding down the third decimal place. The average particle diameter is a value measured using a laser diffraction / scattering particle size distribution analyzer (LMS-2000e manufactured by Seishin Enterprise Co., Ltd.).
　（正極の作製）
　上記正極活物質、アセチレンブラック（導電材、電気化学工業社製）、アクリル系樹脂（バインダー、ＪＳＲ社製）、カルボキシメチルセルロース（増粘材、第一工業製薬社製）を、１００：４：６：１．２の重量比率で、フィルミックス８０－４０型（プライミクス社製）を用いて室温下で正極活物質１００に対して６０重量部の水と共に攪拌混合することで、水性の正極ペーストを得た。この正極ペーストを、圧延アルミニウム箔（厚さ：２０μｍ）の片面上にダイコーターを用いて塗布した。塗布は、正極活物質の塗布量が８ｍｇ／ｃｍ２になる条件下で行った。得られた塗膜を、空気中１００℃で３０分間乾燥し、プレス加工することで、集電体上に厚さ１１０μｍの正極活物質層を備えた正極（塗工面サイズ：２８ｍｍ（縦）×２８ｍｍ（横））を得た。 (Preparation of positive electrode)
The above positive electrode active material, acetylene black (conductive material, manufactured by Denki Kagaku Kogyo), acrylic resin (binder, manufactured by JSR), carboxymethyl cellulose (thickener, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 100: 4: 6 : By stirring and mixing with 60 parts by weight of water with respect to the positive electrode active material 100 at room temperature using a Fillmix 80-40 type (manufactured by Primex) at a weight ratio of 1.2, Obtained. This positive electrode paste was applied on one side of a rolled aluminum foil (thickness: 20 μm) using a die coater. The coating was performed under the condition that the coating amount of the positive electrode active material was 8 mg / cm 2 . The obtained coating film was dried in air at 100 ° C. for 30 minutes and pressed to provide a positive electrode having a 110 μm-thick positive electrode active material layer on the current collector (coating surface size: 28 mm (vertical) × 28 mm (horizontal)) was obtained.
　＜実施例２＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、アルミニウム源としてＡｌＣｌ３・６Ｈ２Ｏ、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ａｌ：Ｐ：Ｓｉがモル比で１．００：１．００：０．０３：０．０３：０．９７：０．０５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 2>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, AlCl 3 .6H 2 O as an aluminum source, and (NH 4 ) as a phosphorus source. 2 HPO 4 , SiO 2 was used as the silicon source. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: Al: P: Si in a molar ratio of 1.00: 1.00: 0.03: 0.03: 0.97: 0. The above substances were weighed so as to be 05. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．００、Ｆｅ量は１．００、Ｚｒ量は０．０３、Ａｌ量は０．０３、Ｐ量は０．９７、Ｓｉ量は０．０５であった。 The obtained positive electrode active material had an Li amount of 1.00, an Fe amount of 1.00, a Zr amount of 0.03, an Al amount of 0.03, a P amount of 0.97, and an Si amount of 0.05. It was.
　正極活物質中、第一化合物はＬｉＦｅ０．９７Ｚｒ０．０２Ａｌ０．０１Ｐ０．９５Ｓｉ０．０５Ｏ４であり、第二化合物はＺｒＯ２、Ａｌ２Ｏ３、ＦｅＰＯ４であり、第二化合物は第一化合物１００重量部に対して４．３重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.97 Zr 0.02 Al 0.01 P 0.95 Si 0.05 O 4 , and the second compound is ZrO 2 , Al 2 O 3 , FePO 4 . The second compound was contained in an amount of 4.3 parts by weight based on 100 parts by weight of the first compound.
　＜実施例３＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．９９：０．０３：１．０１：０．０３となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 3>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and the molar ratio of Li: Fe: Zr: P: Si is 1.03: 0.99: 0.03: 1.01: 0.03 Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．９９、Ｚｒ量は０．０３、Ｐ量は１．０１、Ｓｉ量は０．０３であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.99, a Zr amount of 0.03, a P amount of 1.01, and an Si amount of 0.03.
　正極活物質中、第一化合物はＬｉＦｅ０．９９Ｚｒ０．０１Ｐ０．９７Ｓｉ０．０３Ｏ４であり、第二化合物はＺｒＯ２、Ｌｉ３ＰＯ４、Ｈ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して２．８重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.99 Zr 0.01 P 0.97 Si 0.03 O 4 , the second compound is ZrO 2 , Li 3 PO 4 , H 3 PO 4 , The two compounds were contained in an amount of 2.8 parts by weight based on 100 parts by weight of the first compound.
　＜実施例４＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．９８：０．０４：０．９５：０．０６となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 4>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.98: 0.04: 0.95: 0.06. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．９８、Ｚｒ量は０．０４、Ｐ量は０．９５、Ｓｉ量は０．０６であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.98, a Zr amount of 0.04, a P amount of 0.95, and an Si amount of 0.06.
　正極活物質中、第一化合物はＬｉＦｅ０．９７Ｚｒ０．０３Ｐ０．９４Ｓｉ０．０６Ｏ４であり、第二化合物はＺｒＯ２、Ｌｉ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して１．５重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.97 Zr 0.03 P 0.94 Si 0.06 O 4 , the second compound is ZrO 2 , Li 3 PO 4 , and the second compound is the first The amount was 1.5 parts by weight per 100 parts by weight of the compound.
　＜実施例５＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０２：０．９８：０．０３：０．９７：０．０５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 5>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.02: 0.98: 0.03: 0.97: 0.05. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０２、Ｆｅ量は０．９８、Ｚｒ量は０．０３、Ｐ量は０．９７、Ｓｉ量は０．０５であった。 The obtained positive electrode active material had an Li amount of 1.02, an Fe amount of 0.98, a Zr amount of 0.03, a P amount of 0.97, and an Si amount of 0.05.
　正極活物質中、第一化合物はＬｉＦｅ０．９７Ｚｒ０．０３Ｐ０．９５Ｓｉ０．０５Ｏ４であり、第二化合物はＬｉ２ＨＰＯ４、Ｈ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して１．９重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.97 Zr 0.03 P 0.95 Si 0.05 O 4 , the second compound is Li 2 HPO 4 , H 3 PO 4 , and the second compound is The amount was 1.9 parts by weight with respect to 100 parts by weight of the first compound.
　＜実施例６＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．９８：０．０２：０．９９：０．０４となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 6>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.98: 0.02: 0.99: 0.04. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．９８、Ｚｒ量は０．０２、Ｐ量は０．９９、Ｓｉ量は０．０４であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.98, a Zr amount of 0.02, a P amount of 0.99, and an Si amount of 0.04.
　正極活物質中、第一化合物はＬｉＦｅ０．９８Ｚｒ０．０２Ｐ０．９７Ｓｉ０．０３Ｏ４であり、第二化合物はＬｉ２ＨＰＯ４、ＳｉＯ２であり、第二化合物は第一化合物１００重量部に対して２．３重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.98 Zr 0.02 P 0.97 Si 0.03 O 4 , the second compound is Li 2 HPO 4 , SiO 2 , and the second compound is the first It was 2.3 parts by weight with respect to 100 parts by weight of the compound.
　＜実施例７＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．９９：０．０６：１．０１：０．０４となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 7>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.99: 0.06: 1.01: 0.04 Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．９９、Ｚｒ量は０．０６、Ｐ量は１．０１、Ｓｉ量は０．０４であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.99, a Zr amount of 0.06, a P amount of 1.01, and an Si amount of 0.04.
　正極活物質中、第一化合物はＬｉＦｅ０．９８Ｚｒ０．０２Ｐ０．９６Ｓｉ０．０４Ｏ４であり、第二化合物はＺｒ２Ｐ、Ｌｉ２ＨＰＯ４であり、第二化合物は第一化合物１００重量部に対して４．７重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.98 Zr 0.02 P 0.96 Si 0.04 O 4 , the second compound is Zr 2 P, Li 2 HPO 4 , and the second compound is the first compound. The amount was 4.7 parts by weight per 100 parts by weight of one compound.
　＜実施例８＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．００：０．９９：０．１７：１．０１：０．０４となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 8>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.00: 0.99: 0.17: 1.01: 0.04. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．００、Ｆｅ量は０．９９、Ｚｒ量は０．１７、Ｐ量は１．０１、Ｓｉ量は０．０４であった。 The obtained positive electrode active material had an Li content of 1.00, an Fe content of 0.99, a Zr content of 0.17, a P content of 1.01, and an Si content of 0.04.
　正極活物質中、第一化合物はＬｉＦｅ０．９８Ｚｒ０．０２Ｐ０．９６Ｓｉ０．０４Ｏ４であり、第二化合物はＺｒ３Ｐであり、第二化合物は第一化合物１００重量部に対して９．６重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.98 Zr 0.02 P 0.96 Si 0.04 O 4 , the second compound is Zr 3 P, and the second compound is 100 parts by weight of the first compound. 9.6 parts by weight were included.
　＜実施例９＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．８８：０．１４：０．８６：０．２５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 9>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and the molar ratio of Li: Fe: Zr: P: Si is 1.03: 0.88: 0.14: 0.86: 0.25 Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．８８、Ｚｒ量は０．１４、Ｐ量は０．８６、Ｓｉ量は０．２５であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.88, a Zr amount of 0.14, a P amount of 0.86, and an Si amount of 0.25.
　正極活物質中、第一化合物はＬｉＦｅ０．８８Ｚｒ０．１３Ｐ０．７５Ｓｉ０．２５Ｏ４であり、第二化合物はＺｒ２Ｐ、Ｌｉ３ＰＯ４、Ｈ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して７．５重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.88 Zr 0.13 P 0.75 Si 0.25 O 4 , and the second compound is Zr 2 P, Li 3 PO 4 , H 3 PO 4 , The second compound was contained in an amount of 7.5 parts by weight with respect to 100 parts by weight of the first compound.
　＜実施例１０＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．７５：０．２６：０．５１：０．５０となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 10>
The starting materials are LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Zr: P: Si has a molar ratio of 1.03: 0.75: 0.26: 0.51: 0.50. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｆｅ量は０．７５、Ｚｒ量は０．２６、Ｐ量は０．５１、Ｓｉ量は０．５０であった。 The obtained positive electrode active material had an Li amount of 1.03, an Fe amount of 0.75, a Zr amount of 0.26, a P amount of 0.51, and an Si amount of 0.50.
　正極活物質中、第一化合物はＬｉＦｅ０．７５Ｚｒ０．２５Ｐ０．５Ｓｉ０．５Ｏ４であり、第二化合物はＺｒＯ２、Ｌｉ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して１．４重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.75 Zr 0.25 P 0.5 Si 0.5 O 4 , the second compound is ZrO 2 , Li 3 PO 4 , and the second compound is the first It was contained 1.4 parts by weight with respect to 100 parts by weight of the compound.
　＜実施例１１＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０２：０．９９：０．０２：０．９８：０．０３となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 11>
The starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.02: 0.99: 0.02: 0.98: 0.03. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０２、Ｍｎ量は０．９９、Ｚｒ量は０．０２、Ｐ量は０．９８、Ｓｉ量は０．０３であった。 The obtained positive electrode active material had an Li amount of 1.02, an Mn amount of 0.99, a Zr amount of 0.02, a P amount of 0.98, and an Si amount of 0.03.
　正極活物質中、第一化合物はＬｉＭｎ０．９９Ｚｒ０．０１Ｐ０．９７Ｓｉ０．０３Ｏ４であり、第二化合物はＺｒＯ２、Ｌｉ２Ｏであり、第二化合物は第一化合物１００重量部に対して１．０重量部含まれていた。 In the positive electrode active material, the first compound is LiMn 0.99 Zr 0.01 P 0.97 Si 0.03 O 4 , the second compound is ZrO 2 , Li 2 O, and the second compound is the first compound. 1.0 part by weight was contained with respect to 100 parts by weight.
　＜実施例１２＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．００：０．９８：０．０５：０．９５：０．０５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 12>
The starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.00: 0.98: 0.05: 0.95: 0.05. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．００、Ｍｎ量は０．９８、Ｚｒ量は０．０５、Ｐ量は０．９５、Ｓｉ量は０．０５であった。 The obtained positive electrode active material had an Li amount of 1.00, an Mn amount of 0.98, a Zr amount of 0.05, a P amount of 0.95, and an Si amount of 0.05.
　正極活物質中、第一化合物はＬｉＭｎ０．９８Ｚｒ０．０２Ｐ０．９５Ｓｉ０．０５Ｏ４であり、第二化合物はＺｒＯ２であり、第二化合物は第一化合物１００重量部に対して１．６重量部含まれていた。 In the positive electrode active material, the first compound is LiMn 0.98 Zr 0.02 P 0.95 Si 0.05 O 4 , the second compound is ZrO 2 , and the second compound is in 100 parts by weight of the first compound. In contrast, 1.6 parts by weight were contained.
　＜実施例１３＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、すず源としてＳｎＣｌ４・５Ｈ２Ｏ、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．００：０．９６：０．０５：０．９１：０．０９となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 13>
The starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, SnCl 4 .5H 2 O as a tin source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO 2 as a silicon source. It was used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.00: 0.96: 0.05: 0.91: 0.09 Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．００、Ｍｎ量は０．９６、Ｓｎ量は０．０５、Ｐ量は０．９１、Ｓｉ量は０．０９であった。 The obtained positive electrode active material had an Li content of 1.00, an Mn content of 0.96, an Sn content of 0.05, a P content of 0.91, and an Si content of 0.09.
　正極活物質中、第一化合物はＬｉＭｎ０．９５Ｓｎ０．０５Ｐ０．９１Ｓｉ０．０９Ｏ４であり、第二化合物はＳｎＯ２であり、第二化合物は第一化合物１００重量部に対して０．９重量部含まれていた。 In the positive electrode active material, the first compound is LiMn 0.95 Sn 0.05 P 0.91 Si 0.09 O 4 , the second compound is SnO 2 , and the second compound is 100 parts by weight of the first compound. In contrast, 0.9 part by weight was contained.
　＜実施例１４＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０２：０．８８：０．１３：０．７６：０．２４となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 14>
The starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.02: 0.88: 0.13: 0.76: 0.24. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０２、Ｍｎ量は０．８８、Ｚｒ量は０．１３、Ｐ量は０．７６、Ｓｉ量は０．２４であった。 The obtained positive electrode active material had an Li amount of 1.02, an Mn amount of 0.88, a Zr amount of 0.13, a P amount of 0.76, and an Si amount of 0.24.
　正極活物質中、第一化合物はＬｉＭｎ０．８８Ｚｒ０．１２Ｐ０．７６Ｓｉ０．２４Ｏ４であり、第二化合物はＬｉ２Ｏであり、第二化合物は第一化合物１００重量部に対して０．２重量部含まれていた。 In the positive electrode active material, the first compound is LiMn 0.88 Zr 0.12 P 0.76 Si 0.24 O 4, the second compound is Li 2 O, the second compound first compound 100 parts by weight 0.2 part by weight was included.
　＜実施例１５＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０３：０．７５：０．２６：０．５１：０．５０となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 15>
The starting materials are LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, (NH 4 ) 2 HPO 4 as a phosphorus source, and SiO as a silicon source. 2 was used. The lithium source LiCH 3 COO is 0.6599 g, and Li: Mn: Zr: P: Si has a molar ratio of 1.03: 0.75: 0.26: 0.51: 0.50. Each substance was weighed. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０３、Ｍｎ量は０．７５、Ｚｒ量は０．２６、Ｐ量は０．５１、Ｓｉ量は０．５０であった。 The obtained positive electrode active material had an Li amount of 1.03, an Mn amount of 0.75, a Zr amount of 0.26, a P amount of 0.51, and an Si amount of 0.50.
　正極活物質中、第一化合物はＬｉＭｎ０．７５Ｚｒ０．２５Ｐ０．５Ｓｉ０．５Ｏ４であり、第二化合物はＬｉ３ＰＯ４であり、第二化合物は第一化合物１００重量部に対して０．７重量部含まれていた。 In the positive electrode active material, the first compound is LiMn 0.75 Zr 0.25 P 0.5 Si 0.5 O 4 , the second compound is Li 3 PO 4 , and the second compound is 100 wt% of the first compound. 0.7 parts by weight with respect to parts.
　＜実施例１６＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０４：０．５０：０．４９：０．０２：０．９８：０．０３となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 16>
LiCH 3 COO as a lithium source as a starting material, FeC 2 O 4 .2H 2 O as an iron source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, and a phosphorus source (NH 4 ) 2 HPO 4 , SiO 2 was used as the silicon source. The lithium source LiCH 3 COO is 0.6599 g, and Li: Fe: Mn: Zr: P: Si is 1.04: 0.50: 0.49: 0.02: 0.98: 0. The above substances were weighed so as to be 03. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０４、Ｆｅ量は０．５０、Ｍｎ量は０．４９、Ｚｒ量は０．０２、Ｐ量は０．９８、Ｓｉ量は０．０３であった。 The obtained positive electrode active material had an Li amount of 1.04, an Fe amount of 0.50, an Mn amount of 0.49, a Zr amount of 0.02, a P amount of 0.98, and an Si amount of 0.03. It was.
　正極活物質中、第一化合物はＬｉＦｅ０．５Ｍｎ０．４９Ｚｒ０．０１Ｐ０．９７Ｓｉ０．０３Ｏ４であり、第二化合物はＺｒＯ２、Ｌｉ２Ｏであり、第二化合物は第一化合物１００重量部に対して１．２重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.5 Mn 0.49 Zr 0.01 P 0.97 Si 0.03 O 4 , the second compound is ZrO 2 , Li 2 O, and the second compound Contained 1.2 parts by weight with respect to 100 parts by weight of the first compound.
　＜実施例１７＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、ジルコニウム源としてＺｒＯ（ＣＨ３ＣＯＯ）２、リン源として（ＮＨ４）２ＨＰＯ４、シリコン源としてＳｉＯ２を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｍｎ：Ｚｒ：Ｐ：Ｓｉがモル比で１．０２：０．４８：０．５０：０．０５：０．９５：０．０５となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Example 17>
LiCH 3 COO as a lithium source as a starting material, FeC 2 O 4 .2H 2 O as an iron source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, ZrO (CH 3 COO) 2 as a zirconium source, and a phosphorus source (NH 4 ) 2 HPO 4 , SiO 2 was used as the silicon source. LiCH 3 COO as a lithium source is 0.6599 g, and Li: Fe: Mn: Zr: P: Si is 1.02: 0.48: 0.50: 0.05: 0.95: 0. The above substances were weighed so as to be 05. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質のＬｉ量は１．０２、Ｆｅ量は０．４８、Ｍｎ量は０．５０、Ｚｒ量は０．０５、Ｐ量は０．９５、Ｓｉ量は０．０５であった。 The obtained positive electrode active material had an Li amount of 1.02, an Fe amount of 0.48, an Mn amount of 0.50, a Zr amount of 0.05, a P amount of 0.95, and an Si amount of 0.05. It was.
　正極活物質中、第一化合物はＬｉＦｅ０．４８Ｍｎ０．５Ｓｎ０．０３Ｐ０．９５Ｓｉ０．０５Ｏ４であり、第二化合物はＳｎＯ２、Ｌｉ２Ｏであり、第二化合物は第一化合物１００重量部に対して３．０重量部含まれていた。 In the positive electrode active material, the first compound is LiFe 0.48 Mn 0.5 Sn 0.03 P 0.95 Si 0.05 O 4 , the second compound is SnO 2 , Li 2 O, and the second compound Contained 3.0 parts by weight with respect to 100 parts by weight of the first compound.
　＜比較例１＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、鉄源としてＦｅＣ２Ｏ４・２Ｈ２Ｏ、リン源として（ＮＨ４）２ＨＰＯ４を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｆｅ：Ｐがモル比で１．００：１．００：１．００となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Comparative Example 1>
As starting materials, LiCH 3 COO as a lithium source, FeC 2 O 4 .2H 2 O as an iron source, and (NH 4 ) 2 HPO 4 as a phosphorus source were used. The above-mentioned substances were weighed so that LiCH 3 COO as a lithium source was 0.6599 g and Li: Fe: P was 1.00: 1.00: 1.00 in a molar ratio. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質は、Ｌｉ量が１．００、Ｆｅ量が１．００、Ｐ量が１．００のＬｉＦｅＰＯ４であった。 The obtained positive electrode active material was LiFePO 4 having a Li amount of 1.00, an Fe amount of 1.00, and a P amount of 1.00.
　＜比較例２＞
　出発原料にリチウム源としてＬｉＣＨ３ＣＯＯ、マンガン源としてＭｎ（ＮＯ３）２・６Ｈ２Ｏ、リン源として（ＮＨ４）２ＨＰＯ４を使用した。リチウム源であるＬｉＣＨ３ＣＯＯを０．６５９９ｇとして、Ｌｉ：Ｍｎ：Ｐがモル比で１．００：１．００：１．００となるように上記各物質を秤量した。これらをメノウ乳鉢でよく混合した。この混合体を使用すること以外は、実施例１と同様にして、平均粒径２２μｍの正極活物質を得た。 <Comparative example 2>
LiCH 3 COO as a lithium source, Mn (NO 3 ) 2 .6H 2 O as a manganese source, and (NH 4 ) 2 HPO 4 as a phosphorus source were used as starting materials. The above-mentioned substances were weighed so that LiCH 3 COO as a lithium source was 0.6599 g and Li: Mn: P was 1.00: 1.00: 1.00 in a molar ratio. These were mixed well in an agate mortar. A positive electrode active material having an average particle size of 22 μm was obtained in the same manner as in Example 1 except that this mixture was used.
　得られた正極活物質は、Ｌｉ量が１．００、Ｍｎ量が１．００、Ｐ量が１．００のＬｉＭｎＰＯ４であった。 The obtained positive electrode active material was LiMnPO 4 having a Li amount of 1.00, a Mn amount of 1.00, and a P amount of 1.00.
　実施例及び比較例の正極活物質の組成を表１に示した。なお、表１には、以下で測定する０．１Ｃ及び１０Ｃでの放電容量、レート特性も合わせて示した。表２に第一化合物と第二化合物の種類及び割合を記載した。 Table 1 shows the compositions of the positive electrode active materials of Examples and Comparative Examples. Table 1 also shows the discharge capacity and rate characteristics at 0.1 C and 10 C measured below. Table 2 shows the types and ratios of the first compound and the second compound.
　＜放電容量の測定＞
　放電容量以下の手順で測定した。 <Measurement of discharge capacity>
The discharge capacity was measured by the following procedure.
　まず、放電容量測定用の電池を以下のように用意した。 First, a battery for measuring discharge capacity was prepared as follows.
　上記正極の対極及び参照極としてニッケルメッシュからなる集電体上に積層した金属リチウムを用意した。正極にはアルミニウム製の、対極及び参照極にはニッケル製のタブが設けられ、各タブをステンレス（ＳＵＳ３０４）線を介して外部回路と接続した。上記正極、対極及び参照極を、ガラス容器中の電解液１ｍｏｌ／ＬのＬｉＰＦ６及び１ｍｏｌ／ＬのＶＣ／ＥＣ＋ＤＭＣ＋ＥＭＣ（体積比１：１：１）に浸漬することで、電池を作製した。 As the counter electrode and the reference electrode of the positive electrode, metallic lithium laminated on a current collector made of nickel mesh was prepared. Aluminum tabs were provided for the positive electrode and nickel tabs were provided for the counter and reference electrodes, and each tab was connected to an external circuit via a stainless steel (SUS304) wire. The positive electrode, the counter electrode, and the reference electrode were immersed in 1 mol / L of LiPF 6 and 1 mol / L of VC / EC + DMC + EMC (volume ratio 1: 1: 1) in a glass container to produce a battery.
　（１）０．１Ｃでの放電容量の測定
　電池を２５℃の環境下で充放電を行った。 (1) Measurement of discharge capacity at 0.1 C The battery was charged and discharged in an environment of 25 ° C.
　充電モードはＣＣ―ＣＶで行い、定電流領域での充電レートは０．１Ｃとし、電池の電位が３．６Ｖに到達してから、定電圧領域に移行し、その領域で、充電レートが０．０１Ｃになるまで充電を行い、充電容量を得た。 The charging mode is CC-CV, the charging rate in the constant current region is 0.1 C, and after the battery potential reaches 3.6 V, the charging mode shifts to the constant voltage region, and the charging rate is 0 in that region. The battery was charged until it reached 0.01 C to obtain a charge capacity.
　充電が終了後、放電モードはＣＣで行い、０．１Ｃの放電レートで放電を行い、電池の電位が２．５Ｖに到達した時点で放電を終了させて０．１Ｃでの放電容量を得た。 After charging is completed, the discharge mode is CC, and discharge is performed at a discharge rate of 0.1 C. When the battery potential reaches 2.5 V, the discharge is terminated to obtain a discharge capacity at 0.1 C. .
　（２）１０Ｃでの放電容量の測定
　充放電レートを１０Ｃとすること以外は、上記０．１Ｃでの放電容量の測定と同様にして、１０Ｃでの放電容量を得た。 (2) Measurement of discharge capacity at 10C A discharge capacity at 10C was obtained in the same manner as the measurement of the discharge capacity at 0.1C except that the charge / discharge rate was set at 10C.
　（３）レート特性
　レート特性は、１０Ｃでの放電容量を０．１Ｃでの放電容量で除することで算出した。 (3) Rate characteristics The rate characteristics were calculated by dividing the discharge capacity at 10C by the discharge capacity at 0.1C.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１から、実施例の正極活物質は、充放電レート１０Ｃの高入出力条件でも、充放電レート０．１Ｃの低入出力条件と比較して、放電容量の低下を抑制できていることが分かる。第二化合物が存在しない比較例に比べて、実施例のレート特性が向上していることから、この向上は第二化合物の存在によることが分かる。 From Table 1, it can be seen that the positive electrode active materials of the examples were able to suppress a decrease in discharge capacity even under a high input / output condition with a charge / discharge rate of 10C, compared with a low input / output condition with a charge / discharge rate of 0.1C. I understand. Compared with the comparative example in which the second compound does not exist, the rate characteristics of the examples are improved, and it can be seen that this improvement is due to the presence of the second compound.
　本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。さらに、各実施形態にそれぞれ開示された技術的手段を組み合わせることにより、新しい技術的特徴を形成することができる。 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.
　本発明は、リチウムイオン二次電池に含まれる正極活物質全般に広く適用できる。特に、長期の充放電サイクル寿命と高い入出力特性とを要するＨＥＶやＥＶ等に適用できる。 The present invention can be widely applied to all positive electrode active materials included in lithium ion secondary batteries. In particular, it can be applied to HEVs and EVs that require a long charge / discharge cycle life and high input / output characteristics.
１　リン酸複合化合物（第一化合物）
２　正極集電体
３　第二化合物
  1 Phosphate complex compound (first compound)
2 Positive current collector 3 Second compound

Claims (5)

  1. 　リチウムイオン二次電池用の正極活物質であり、
    　前記正極活物質が、Ｌｉ、Ｍ、Ｚ、Ｐ、Ｓｉ及びＯ（Ｍは、Ｆｅ及びＭｎのいずれか一方又は両方であり、ＺはＣｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ及びＹからなる群から選択される少なくとも１種の元素又はそれらの組み合わせである）から構成されるリン酸複合化合物である第一化合物と、
    　酸化物及びリン化物のいずれか一方又は両方からなる第二化合物と
    を含み、
    　前記第二化合物が、
    （ｉ）前記第一化合物中のＭが、Ｆｅである場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ及びＳｉから選択される元素の酸化物及びリン化物、並びにＺｒ、Ｓｎ、Ａｌ及びＹから選択される元素のリン化物から少なくとも１種選択され、
    （ｉｉ）前記第一化合物中のＭが、Ｍｎを含む場合、Ｌｉ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｚｒ、Ｓｎ、Ａｌ、Ｙ及びＳｉから選択される元素の酸化物及びリン化物から少なくとも１種選択され、
    　前記第一化合物と前記第二化合物が、それらの混合物として、下記一般式（１）：
    ＬｉａＭｂＺｃＰｄＳｉｅＯｆ　　（１）
    （１．０≦ａ≦１．１、０．７５≦ｂ≦０．９９、０＜ｃ≦０．３、０．５≦ｄ≦１．１、０＜ｅ≦０．６、３≦ｆ≦５である）で表される正極活物質。     A positive electrode active material for a lithium ion secondary battery,
    The positive electrode active material is Li, M, Z, P, Si, and O (M is one or both of Fe and Mn, and Z is a group consisting of Co, Ni, Zr, Sn, Al, and Y). A first compound which is a phosphoric acid complex compound composed of at least one selected element or a combination thereof;
    A second compound comprising either one or both of an oxide and a phosphide,
    The second compound is
    (I) when M in the first compound is Fe, selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni and Si, and Zr, Sn, Al and Y At least one selected from phosphides of the element
    (Ii) When M in the first compound contains Mn, at least one element selected from oxides and phosphides of elements selected from Li, Fe, Mn, Co, Ni, Zr, Sn, Al, Y, and Si. Species selected,
    The first compound and the second compound, as a mixture thereof, have the following general formula (1):
    Li a M b Z c P d Si e O f (1)
    (1.0 ≦ a ≦ 1.1, 0.75 ≦ b ≦ 0.99, 0 <c ≦ 0.3, 0.5 ≦ d ≦ 1.1, 0 <e ≦ 0.6, 3 ≦ f ≦ 5)).
  2. 　前記第二化合物が、前記第一化合物１００重量部に対して、０．１～１０重量部含まれる請求項１に記載の正極活物質。 The positive electrode active material according to claim 1, wherein the second compound is contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the first compound.
  3. 　前記第二化合物が、Ｌｉ３ＰＯ４、ＺｒＯ２、ＳｉＯ２、Ｚｒ２Ｐ及びＺｒ３Ｐから選択される請求項１又は２に記載の正極活物質。 The positive electrode active material according to claim 1, wherein the second compound is selected from Li 3 PO 4 , ZrO 2 , SiO 2 , Zr 2 P, and Zr 3 P.
  4. 　前記ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．１、０．８７５≦ｂ≦０．９９、０＜ｃ≦０．１２５、０．７５≦ｄ≦１．０５、０＜ｅ≦０．２５である請求項１～３のいずれか１項に記載の正極活物質。 A, b, c, d and e are 1.01 ≦ a ≦ 1.1, 0.875 ≦ b ≦ 0.99, 0 <c ≦ 0.125, 0.75 ≦ d ≦ 1.05, The positive electrode active material according to any one of claims 1 to 3, wherein 0 <e≤0.25.
  5. 　前記ａ、ｂ、ｃ、ｄ及びｅが、１．０１≦ａ≦１．０５、０．９４≦ｂ≦０．９９、０．０１≦ｃ≦０．０６、０．９７≦ｄ≦１．０２、０．０２≦ｅ≦０．０６である請求項１～４のいずれか１項に記載の正極活物質。 A, b, c, d and e are 1.01 ≦ a ≦ 1.05, 0.94 ≦ b ≦ 0.99, 0.01 ≦ c ≦ 0.06, 0.97 ≦ d ≦ 1. The positive electrode active material according to any one of claims 1 to 4, wherein 02 and 0.02 ≦ e ≦ 0.06.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010134579A1 (en) * 2009-05-22 2010-11-25 シャープ株式会社 Positive pole active material, positive pole, and nonaqueous secondary cell
WO2012061934A1 (en) * 2010-11-11 2012-05-18 Phostech Lithium Inc. Carbon-deposited alkali metal phosphosilicate cathode material and process for preparing same including two dry high-energy milling steps
WO2013100651A1 (en) * 2011-12-30 2013-07-04 삼성정밀화학 주식회사 Cathode active material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery including same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010134579A1 (en) * 2009-05-22 2010-11-25 シャープ株式会社 Positive pole active material, positive pole, and nonaqueous secondary cell
WO2012061934A1 (en) * 2010-11-11 2012-05-18 Phostech Lithium Inc. Carbon-deposited alkali metal phosphosilicate cathode material and process for preparing same including two dry high-energy milling steps
WO2013100651A1 (en) * 2011-12-30 2013-07-04 삼성정밀화학 주식회사 Cathode active material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery including same

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