WO2022024675A1 - Method for selecting substitution elements, positive electrode active material, positive electrode, non-aqueous electrolyte power storage element, power storage device, method for manufacturing positive electrode active material, method for manufacturing positive electrode, and method for manufacturing non-aqueous electrolyte power storage element - Google Patents

Method for selecting substitution elements, positive electrode active material, positive electrode, non-aqueous electrolyte power storage element, power storage device, method for manufacturing positive electrode active material, method for manufacturing positive electrode, and method for manufacturing non-aqueous electrolyte power storage element Download PDF

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WO2022024675A1
WO2022024675A1 PCT/JP2021/025232 JP2021025232W WO2022024675A1 WO 2022024675 A1 WO2022024675 A1 WO 2022024675A1 JP 2021025232 W JP2021025232 W JP 2021025232W WO 2022024675 A1 WO2022024675 A1 WO 2022024675A1
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positive electrode
active material
electrode active
oxide
substitution
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Japanese (ja)
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克弥 西井
祐介 水野
祐一 池田
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株式会社Ｇｓユアサ
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/20—Silicates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B35/00—Boron; Compounds thereof
    • C01B35/08—Compounds containing boron and nitrogen, phosphorus, oxygen, sulfur, selenium or tellurium
    • C01B35/10—Compounds containing boron and oxygen
    • C01B35/12—Borates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G51/00—Compounds of cobalt
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/46—Metal oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
    • H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes
    • 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
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a method for selecting a substitution element, a positive electrode active material, a positive electrode, a non-aqueous electrolyte power storage element, a power storage device, a positive electrode active material manufacturing method, a positive electrode manufacturing method, and a non-aqueous electrolyte power storage element manufacturing method.
  • Non-aqueous electrolyte secondary batteries represented by lithium-ion secondary batteries are widely used in personal computers, electronic devices such as communication terminals, automobiles, etc. due to their high energy density.
  • the non-aqueous electrolyte secondary battery generally has a pair of electrodes electrically separated by a separator and a non-aqueous electrolyte interposed between the electrodes, and transfers ions between the two electrodes. It is configured to charge and discharge.
  • capacitors such as lithium ion capacitors and electric double layer capacitors are also widely used as non-aqueous electrolyte storage elements other than non-aqueous electrolyte secondary batteries.
  • Various active materials are used for the positive electrode and the negative electrode of the non-aqueous electrolyte power storage element, and various composite oxides are widely used as the positive electrode active material.
  • the positive electrode active materials a transition metal solid-dissolved metal oxide in which a transition metal element such as Co or Fe is solid-dissolved in Li 2 O has been developed (see Patent Documents 1 and 2). Further, a positive electrode active material in which a typical element such as Al is dissolved in Li 2 O together with Co has also been proposed (see Patent Document 3).
  • the positive electrode active material in which one or more kinds of elements are solid-dissolved in the conventional Li 2 O as described above has been improved in various ways with respect to Li 2 O, it is charged when the amount of charging electricity is increased.
  • the ratio of the amount of discharged electricity to the amount of electricity, that is, the Coulomb efficiency is low.
  • the positive electrode active material in which one or more kinds of elements are solid-solved in the conventional Li 2 O has the disadvantage that the effective electric energy is small.
  • by actually synthesizing various kinds of positive electrode active materials in which various elements are dissolved in Li 2 O and evaluating all of these performances it is possible to find a positive electrode active material having good performance. Is possible.
  • the present invention has been made based on the above circumstances, and an object thereof is when the amount of electricity for charging is relatively large (for example, when the amount of electricity for charging per mass of the positive electrode active material is 400 mAh / g or more). ) Also, a method for efficiently selecting a substitution element suitable for the oxide contained in the positive electrode active material having high Coulomb efficiency, a positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large, such a positive electrode activity.
  • One aspect of the present invention is the first substitution element and the second substitution in a positive electrode active material containing lithium, a first substitution element and a second substitution element, and containing an oxide having an inverted fluorite-type crystal structure.
  • the first substitution element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups
  • the second substitution element is the second to the second group. It is an element other than nitrogen, oxygen, sulfur and selenium that belongs to any of Group 5 and Groups 12 to 16, and is the calculation result based on the first principle calculation as the first substitution element and the second substitution element.
  • Is a method for selecting a substitution element which comprises selecting a combination satisfying the following conditions A and B.
  • the abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value.
  • the abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
  • Another aspect of the present invention contains an oxide containing lithium, a first substituted element and a second substituted element and having an inverted fluorite-type crystal structure, and the first substituted element is from Group 6
  • It is an element other than sulfur and selenium, and is a positive electrode active material (A) in which the first substitution element and the second substitution element are a combination in which the calculation result based on the first principle calculation satisfies the following conditions a and b. ..
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • Another aspect of the present invention comprises the first and second substituents and lithium selected using the method for selecting a substituent according to one aspect of the present invention, and has an inverted fluorite-type crystal structure. It contains an oxide having an oxide, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0.53.
  • the positive electrode active material (B) has a predetermined value of the abundance ratio of 0.11.
  • Another aspect of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing a positive electrode active material (A) or a positive electrode active material (B) according to one aspect of the present invention.
  • Another aspect of the present invention is a non-aqueous electrolyte power storage element provided with a positive electrode according to one aspect of the present invention.
  • Another aspect of the present invention is a power storage device including a plurality of non-aqueous electrolyte power storage elements and one or more non-water electrolyte power storage elements according to one aspect of the present invention.
  • Another aspect of the present invention is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. It is a method (A) for producing a positive electrode active material comprising treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to one aspect of the present invention.
  • the combination of the first substitution element and the second substitution element is selected by the method for selecting a substitution element according to one aspect of the present invention, and lithium, oxygen, and the first substitution are used. It is a method (B) for producing a positive electrode active material, which comprises treating a material containing an element and the second substituted element by a mechanochemical method.
  • Another aspect of the present invention is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure.
  • the technetium and tungsten are provided by treating a material containing oxygen, the first substitution element and the second substitution element by a mechanochemical method, and the first substitution element belongs to any of Group 6 to Group 11.
  • the second substitution element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is the first element.
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • Another aspect of the present invention is the positive electrode active material (A) or the positive electrode active material (B) according to the one aspect of the present invention, or the methods (A) to (C) for producing the positive electrode active material according to the one aspect of the present invention. It is a method of manufacturing a positive electrode for a non-aqueous electrolyte power storage element, which comprises producing a positive electrode using the positive electrode active material obtained in any of the above.
  • Another aspect of the present invention is a method for manufacturing a non-aqueous electrolyte power storage element, which comprises a method for manufacturing a positive electrode according to one aspect of the present invention.
  • a method for efficiently selecting a substitution element suitable for an oxide contained in a positive electrode active material having a high Coulomb efficiency even when the amount of charging electricity is relatively large the amount of charging electricity is A positive electrode active material having a high Coulomb efficiency even when it is relatively large, a positive electrode having such a positive electrode active material, a non-aqueous electrolyte power storage element, and a power storage device, a method for manufacturing the positive electrode active material, a method for manufacturing the positive electrode, and the above non. It is possible to provide a method for manufacturing a water electrolyte storage element.
  • FIG. 1 is an external perspective view showing a non-aqueous electrolyte power storage element according to an embodiment of the present invention.
  • FIG. 2 is a schematic view showing a power storage device configured by assembling a plurality of non-aqueous electrolyte power storage elements according to an embodiment of the present invention.
  • FIG. 3 is an X-ray diffraction diagram using CuK ⁇ rays of each positive electrode active material obtained in Examples 2 and 3 and Comparative Examples 1 and 2.
  • FIG. 4 is an X-ray diffraction diagram using CuK ⁇ rays of each positive electrode active material obtained in Examples 4 and 5.
  • FIG. 1 is an external perspective view showing a non-aqueous electrolyte power storage element according to an embodiment of the present invention.
  • FIG. 2 is a schematic view showing a power storage device configured by assembling a plurality of non-aqueous electrolyte power storage elements according to an embodiment of the present invention.
  • FIG. 3 is an X-ray diffraction diagram using CuK
  • FIG. 5 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell of Example 17 (positive electrode active material Li 1.444 Co 0.194 B 0.056 O).
  • FIG. 6 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell (positive electrode active material Li 1.389 Co 0.139 Al 0.111 O) of Comparative Example 7.
  • the method for selecting a substitution element is the above-mentioned first method for a positive electrode active material containing lithium, a first substitution element and a second substitution element, and an oxide having an inverted fluorite-type crystal structure.
  • Condition A The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
  • a substitution element suitable for an oxide contained in a positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large is efficiently selected. Can be done.
  • the reason for this is as follows.
  • a primary substituent such as Co is dissolved in Li 2 O
  • proximity (migration) between the primary substituents is likely to occur in a charged state.
  • the abundance ratio of the first substituted element having an oxygen coordination number of 4 decreases, and the abundance ratio of the first substituted element having an oxygen coordination number of 6 coordinates decreases.
  • the catalytic activity for expressing the oxygen redox reaction decreases.
  • the Coulomb efficiency decreases with repeated charging and discharging. Further, in the case of a positive electrode active material in which Al as a second substitution element is further dissolved in Li 2O together with Co or the like as a first substitution element, it is considered that migration between the first substitution elements is suppressed by Al. However, as a result of further solid-solving Al, oxygen gas is likely to be released during charging, so that the Coulomb efficiency is not sufficiently improved.
  • the oxygen coordination number is 4 coordinations in a charged state as condition A in the calculation result based on the first-principles calculation.
  • the selection method by selecting a combination of the first substitution element and the second substitution element whose calculation results based on the first-principles calculation satisfy the conditions A and B, the Coulomb can be charged even when the amount of charging electricity is relatively large. It is possible to efficiently select a substitution element suitable for the oxide contained in the highly efficient positive electrode active material.
  • the positive electrode active material according to one aspect of the present invention contains lithium, a first substituted element and a second substituted element, and contains an oxide having an inverted fluorite-type crystal structure, and the first substituted element is the first.
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • the positive electrode active material (A) has high Coulomb efficiency even when the amount of charging electricity is relatively large. Further, the positive electrode active material (A) tends to maintain this high Coulomb efficiency even after repeated charging and discharging.
  • oxygen redox activation is achieved by satisfying the condition a that the abundance ratio of the first substituted element having four coordination numbers of oxygen in a predetermined charging state is high in the calculation result based on the first-principles calculation. It is presumed that the release of oxygen gas is suppressed by satisfying the condition b that the decrease in function is suppressed and the abundance ratio of oxygen whose charge is larger than ⁇ 0.5 in a predetermined charge state is low.
  • the coulombic efficiency is high even when the amount of charging electricity is relatively large, and it becomes easy to maintain this high coulombic efficiency even after repeated charging and discharging. It is presumed that it is.
  • the second substitution element is an element having an effective ionic radius of Shannon of less than 0.60 ⁇ .
  • the anion is an oxide ion
  • a four-coordination structure is likely to be formed if the ionic radius of the cation is less than 0.60 ⁇ . Therefore, in the positive electrode active material (A), when the effective ionic radius of the second substituent is less than 0.60 ⁇ , a four-coordination structure is likely to be formed, and the stability of the inverted fluorite-type crystal structure is enhanced. Therefore, when the second substitution element is such an element, the coulomb efficiency is higher even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulomb efficiency even after repeated charging and discharging.
  • the effective ionic radius of Shannon is based on the description in the following documents.
  • the effective ionic radius of the second substitution element is the ionic radius in the state (valence) of the cation in the oxide contained in the positive electrode active material (A). That is, when the second substitution element is present in the oxide in the state of a trivalent cation, for example, it is set as the effective ionic radius of this trivalent cation. Further, the effective ionic radius of the second substitution element is a value when the coordination number is four coordinations, and in the case of an element having a plurality of spin states, it is a value when the coordination number is a high spin state.
  • the first substituent is cobalt, iron, copper, manganese, nickel, chromium or a combination thereof
  • the second substituent is boron, carbon, magnesium, silicon, or a combination thereof. It is preferably phosphorus, titanium, gallium, tin or a combination thereof.
  • the positive electrode active material according to another aspect of the present invention contains the first and second substitution elements and lithium selected by using the method for selecting a substitution element according to one aspect of the present invention, and is a reverse fluorite. It contains an oxide having a type crystal structure, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0.53. , The positive electrode active material (B) in which the predetermined value of the abundance ratio under the above condition B is 0.11.
  • the positive electrode active material (B) also has high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency even when charging and discharging are repeated, for the reason that it is presumed to be the same as the positive electrode active material (A) described above. Is easy to maintain.
  • the half width of the diffraction peak in which the diffraction angle 2 ⁇ is around 33 °. Is preferably 0.3 ° or more.
  • the diffraction peak in which the diffraction angle 2 ⁇ is around 33 ° refers to the peak having the strongest diffraction intensity in the range of the diffraction angle 2 ⁇ of 30 ° to 35 °.
  • the X-ray diffraction measurement of the oxide is carried out by powder X-ray diffraction measurement using an X-diffraction device (“MiniFlex II” manufactured by Rigaku Co., Ltd.) with a CuK ⁇ ray as the radiation source, a tube voltage of 30 kV, and a tube current of 15 mA.
  • the diffracted X-rays pass through a K ⁇ filter having a thickness of 30 ⁇ m and are detected by a high-speed one-dimensional detector (D / teX Ultra 2).
  • the sampling width is 0.02 °
  • the scan speed is 5 ° / min
  • the divergent slit width is 0.625 °
  • the light receiving slit width is 13 mm (OPEN)
  • the scattering slit width is 8 mm.
  • the X-ray diffraction pattern obtained by the above-mentioned X-ray diffraction measurement is automatically analyzed using PDXL (analysis software, manufactured by Rigaku).
  • PDXL analysis software, manufactured by Rigaku
  • "precision background” and “automatic” are selected in the work window of the PDXL software, and the strength error between the measured pattern and the calculated pattern is refined to 1000 or less. Background processing is performed by this refinement, and the value of the peak intensity of each diffraction line, the value of the half width, and the like are obtained as the values obtained by subtracting the baseline.
  • the positive electrode according to one aspect of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing the positive electrode active material (A) or the positive electrode active material (B) according to one aspect of the present invention. Since the positive electrode contains the positive electrode active material (A) or the positive electrode active material (B) according to one aspect of the present invention, the coulombic efficiency is high even when the amount of charging electricity is relatively large, and this is high even when charging and discharging are repeated. Coulomb efficiency is easy to maintain.
  • the non-aqueous electrolyte power storage element according to one aspect of the present invention is a non-aqueous electrolyte power storage element having a positive electrode according to one aspect of the present invention (hereinafter, may be simply referred to as “storage element”).
  • the power storage element has a high coulombic efficiency even when the amount of charging electricity is relatively large, and the high coulombic efficiency is likely to be maintained even after repeated charging and discharging.
  • the power storage device is a power storage device including a plurality of non-aqueous electrolyte power storage elements and one or more non-water electrolyte power storage elements according to one aspect of the present invention.
  • the power storage device has a high coulombic efficiency even when the amount of charging electricity is relatively large, and it is easy to maintain this high coulombic efficiency even after repeated charging and discharging.
  • the method for producing a positive electrode active material produces a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure.
  • a method for producing a positive electrode active material which comprises treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to one aspect of the present invention.
  • the method for producing a positive electrode active material (A) it is possible to produce a positive electrode active material which has a high coulombic efficiency even when the amount of charging electricity is relatively large and can easily maintain this high coulombic efficiency even after repeated charging and discharging. can.
  • a combination of the first substitution element and the second substitution element is selected by the method for selecting a substitution element according to one aspect of the present invention, and the combination of the first substitution element and the second substitution element is selected. It is a method (B) for producing a positive electrode active material comprising treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method.
  • the coulombic efficiency is high even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulombic efficiency even after repeated charging and discharging. ..
  • the method for producing a positive electrode active material is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure.
  • the production method comprises treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method, and the first substitution element is a group 6 to 11 of the above.
  • the method (C) for producing a positive electrode active material wherein the first substitution element and the second substitution element are a combination of the above-mentioned first substitution element and the above-mentioned second substitution element, and the calculation result based on the first-principles calculation satisfies the following conditions a and b.
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • the coulombic efficiency is high even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulombic efficiency even after repeated charging and discharging. ..
  • the method for producing a positive electrode according to one aspect of the present invention is the positive electrode active material (A) or positive electrode active material (B) according to one aspect of the present invention, or the method for producing a positive electrode active material according to one aspect of the present invention (A).
  • a method for manufacturing a positive electrode for a non-aqueous electrolyte power storage element which comprises producing a positive electrode using the positive electrode active material obtained in any of (C).
  • the coulomb efficiency is high even when the amount of charging electricity is relatively large, and it is possible to manufacture a positive electrode in which this high coulomb efficiency can be easily maintained even after repeated charging and discharging.
  • the method for manufacturing a non-aqueous electrolyte power storage element according to one aspect of the present invention is a method for manufacturing a non-aqueous electrolyte power storage element including the method for manufacturing a positive electrode according to one aspect of the present invention.
  • the coulomb efficiency is high even when the amount of charging electricity is relatively large, and the non-water electrolyte power storage element which can easily maintain this high coulomb efficiency even after repeated charging and discharging is manufactured. Can be done.
  • a method for selecting a substitution element a method for producing a positive electrode active material, a method for producing a positive electrode active material, a method for producing a positive electrode and a positive electrode, a method for producing a non-aqueous electrolyte power storage element, and a method for producing a non-aqueous electrolyte power storage element according to an embodiment of the present invention will be provided. , Will be explained in order.
  • the method for selecting a substitution element according to an embodiment of the present invention is the above-mentioned first in a positive electrode active material containing lithium, a first substitution element and a second substitution element, and containing an oxide having an inverted fluorite-type crystal structure.
  • the element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is used as the first substitution element and the second substitution element.
  • It is a method of selecting a substitution element comprising selecting a combination in which the calculation result based on the first-principles calculation satisfies the following conditions A and B.
  • Condition A The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
  • First-principles calculation is an ab initio prediction method that can calculate the total energy of a model including atoms with known atomic numbers and spatial coordinates, and the energy band structure of electrons. Is. Structure optimization is possible by calculating the force acting on the atom, and the lattice constant, stable structure at 0K, band gap, etc. can be calculated. There are roughly two types of calculation methods, the "wave function theory” system and the “density functional theory” system. The calculation method used in the present specification is based on the density functional theory.
  • the method for selecting a substitution element according to an embodiment of the present invention can be specifically carried out by the following procedures (1) to (3).
  • the candidate oxide is first selected.
  • This oxide (candidate oxide) contains lithium, a first-substituted element and a second-substituted element, and has an inverted fluorite-type crystal structure.
  • the first substituent contained in the candidate oxide is an element other than technetium and tungsten belonging to any of Group 6 to Group 11, and examples thereof include cobalt, iron, copper, manganese, nickel, and chromium. ..
  • the second substitution element contained in the candidate oxide is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is, for example, boron and carbon. , Magnesium, silicon, phosphorus, titanium, gallium, tin and the like.
  • the composition ratio of the elements constituting the candidate oxide is not particularly limited as long as it can have an inverted fluorite-type crystal structure, but for example, it has a composition formula represented by the following formula (1). It's okay. [Li 2-2z M 2x A 2y ] O ... (1)
  • M is a first substitution element.
  • A is a second substitution element.
  • x, y and z satisfy the following formulas (a) to (c). 0 ⁇ x ⁇ 1 ... (a) 0 ⁇ y ⁇ 1 ... (b) x + y ⁇ z ⁇ 1 ... (c)
  • composition formula of the candidate oxide may be represented by the following formula (2).
  • M is a first substitution element.
  • A is a second substitution element.
  • m is an integer based on the stoichiometric ratio.
  • n is an integer of 1 or more and 8 or less. n can be, for example, 5 or 7.
  • a genetic algorithm is a kind of optimization algorithm that imitates the process of biological evolution, and by repeating the work of preferentially rearranging excellent genes from multiple individuals whose parameters are represented by genes, the optimum individual can be selected in a short period of time. It is a method that can be searched between.
  • An example of the calculation conditions of the genetic algorithm is shown below. Number of genes per individual: 1 Number of individuals generated per generation: 20 Percentage of individuals to survive per generation: 0.6 Ratio of two-point crossover: 0.4 Uniform crossover ratio: 0.4 Number of top individuals to pass on to the next generation unconditionally without genetic manipulation: 3 Probability of uniform crossover: 0.8 Mutation probability: 0.02 Maximum number of generations: 200 Convergence test: When the most stable individual is not updated for 10 consecutive generations
  • VASP Vienna Ab-initio Simulation Package
  • An example of the calculation condition can be as follows. Cut-off energy of plane wave basis set: 400eV Approximation of exchange correlation interaction: GGA + U Pseudopotential: PAW (PBEsol) k point: gamma point energy smearing: Gaussian method
  • VASP Vienna Ab-initio Simulation Package
  • An example of the calculation condition can be as follows.
  • the k point is set so that the value of k-resolution is about 1000.
  • the k-resolution is the product of the number of atoms in the model and the k points in the a, b, and c axis directions.
  • Approximation of exchange correlation interaction GGA +
  • U Pseudopotential PAW (PBEsol)
  • k point k-resolution ⁇ 1000
  • Energy smearing Gaussian method
  • the 3d orbital is the outermost shell orbital, and the 3d orbital is not a closed shell in the state of a cation with a stable valence, and the transition metal elements vanadium, chromium, manganese, iron, cobalt and cobalt in which electrons exist in the 3d orbital.
  • the Hubbard Ueff value shown in Table 1 can be used as a calculation condition. As a result, the effect of electron localization in the d-orbital is reflected in the calculation.
  • the Hubbard Ueff values shown in Table 1 are taken from the calculation conditions of the first-principles calculation carried out in the crystal structure database Materials Project (https://materialsproject.org/#search/materials) (2020). As of May 15, 2014).
  • the Ueff value can be obtained by searching the database for materials containing vanadium, chromium, manganese, iron, cobalt and nickel.
  • condition A the abundance ratio of the first substituent having an oxygen coordination number of four to all the first substituents of the candidate oxide in a predetermined charged state is obtained.
  • the predetermined charging state may be appropriately set according to the type of the first substitution element and the like, but can be, for example, a state of charging up to 400 mAh / g.
  • the predetermined value (threshold value) of the above condition A may be appropriately set according to the type of the first substitution element and the like, but may be, for example, 0.53, even if it is 0.6, 0.7 or the like. good.
  • condition B the abundance ratio of oxygen having a charge greater than -0.5 with respect to all oxygen of the candidate oxide in a predetermined charged state is obtained.
  • the predetermined charging state may be appropriately set according to the type of the first substitution element and the like, but can be, for example, a state of charging up to 400 mAh / g.
  • the charging states under condition A and condition B may be the same or different, but are preferably the same.
  • the above-mentioned charge is a charge (Bader charge) obtained by the Bader charge analysis method.
  • the predetermined value (threshold value) of the above condition B may be appropriately set according to the type of the first substitution element and the like, but may be, for example, 0.11, 0.10, 0.08, 0.06, etc. It may be 0.04 mag.
  • the first and second substituents contained in the candidate oxides satisfying the above conditions A and B are suitable for oxides contained in the positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large. It can be selected as a combination of substituents.
  • the positive electrode active material (A) contains lithium, a first substitution element and a second substitution element, and contains an oxide having an inverted fluorite-type crystal structure, and the first substitution is described above.
  • the element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups
  • the second substitution element is any of the 2nd to 5th groups and the 12th to 16th groups.
  • a positive electrode which is an element other than nitrogen, oxygen, sulfur and selenium belonging to the above, and is a combination of the first substitution element and the second substitution element in which the calculation result based on the first principle calculation satisfies the following conditions a and b. It is an active material.
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • the positive electrode active material (A) contains "lithium, a first-substituted element and a second-substituted element" contained in the positive electrode active material (A), and has an inverted fluorite-type crystal structure.
  • the result of the first-principles calculation based on the composition of the "oxide having” may satisfy the above conditions a and b.
  • the positive electrode active material (A) according to the embodiment of the present invention contains lithium, a first-substituted element and a second-substituted element, and contains an oxide having an inverted fluorite-type crystal structure.
  • the first substitution element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups
  • the second substitution element is the 2nd to 5th group and the 12th to 16th group. It is an element other than nitrogen, oxygen, sulfur and selenium that belongs to any of the groups
  • the above oxide is a positive electrode active material for which the calculation result based on the first-principles calculation satisfies the above conditions a and b. It's okay.
  • the positive electrode active material (A) has a high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency is likely to be maintained even after repeated charging and discharging.
  • VASP Vienna Ab-initio Simulation Package
  • a stable atomic arrangement is calculated according to the method of the above-mentioned "(2) determination of atomic arrangement”.
  • the conditions specifically mentioned in the explanation of "(2) Determination of atomic arrangement” are adopted.
  • the examination is carried out according to the method described in the above-mentioned "(3) Examination of condition A and condition B".
  • the predetermined charging state under the above condition A and condition B is charged to 400 mAh / g.
  • the predetermined value of the abundance ratio in the condition A is set to 0.53
  • the predetermined value of the abundance ratio in the condition B is set to 0.11, and it is examined whether or not the condition a and the condition b are satisfied.
  • the calculation of each abundance ratio according to the condition a and the condition b is performed by the following method.
  • ⁇ Condition a By counting the number of oxygen existing in the space within a radius of 2.5 ⁇ with the first substituted element as the center, the coordination number of oxygen with respect to the first substituted element is calculated. This evaluation was performed for all the first substituted elements contained in all five models, and the abundance ratio of the first substituted element having an oxygen coordination number of four to all the first substituted elements was calculated. do.
  • ⁇ Condition b The Bader charge analysis method is used to calculate the charge of all oxygen in all five models. Then, the abundance ratio of oxygen having a charge greater than ⁇ 0.5 is calculated for all oxygen.
  • the abundance ratio of the first substituent having an oxygen coordination number of 4 under the condition a is 0.53 or more, preferably 0.6 or more, and more preferably 0.7 or more.
  • the decrease in the catalytic activity for expressing the oxygen redox reaction is further suppressed, the Coulomb efficiency is further increased when the amount of charging electricity is relatively large, and this high Coulomb efficiency is further enhanced even if charging and discharging are repeated. It will be easier to maintain.
  • the upper limit of the abundance ratio of the first substituent having four coordination numbers of oxygen may be 1, and may be 0.95 or 0.9.
  • the abundance ratio of oxygen having a charge greater than ⁇ 0.5 under condition b is 0.11 or less, preferably 0.10 or less, and more preferably 0.08, 0.06 or 0.04 or less. In such a case, the release of oxygen gas is further suppressed, the Coulomb efficiency when the amount of charging electricity is relatively large is further increased, and this high Coulomb efficiency is more likely to be maintained even after repeated charging and discharging.
  • the lower limit of the abundance ratio of oxygen having an electric charge greater than ⁇ 0.5 may be 0 or 0.01.
  • the first substitution element is not particularly limited as long as it is an element other than technetium and tungsten belonging to any of Group 6 to Group 11, but cobalt, iron, copper, manganese, nickel, chromium or a combination thereof is preferable. , Cobalt is more preferred, and cobalt is even more preferred.
  • the second substitution element is not particularly limited as long as it is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, but enhances structural stability. From these viewpoints, among these, elements belonging to any of Group 2 to Group 4 and Group 13 to Group 15 are preferable, and elements belonging to any of Group 13 to Group 15 are more preferable. In some cases.
  • the second substituent is preferably an element having an effective ionic radius of Shannon of less than 0.60 ⁇ in a cation state in the oxide, preferably an element having a radius of less than 0.50 ⁇ , from the viewpoint of enhancing structural stability. May be more preferred, and elements less than 0.40 ⁇ may be even more preferred.
  • Specific second substitution elements include boron (B 3+ 0.11 ⁇ ; Shannon's effective ionic radius, the same applies hereinafter), carbon (C 4 + 0.15 ⁇ ), magnesium (Mg 2 + 0.57 ⁇ ), and silicon (Si 4 + ).
  • the molar ratio (II / (I + II)) of the content of the second substituent (II) to the total content of the first substituted element (I) and the second substituted element (II) in the oxide is not particularly limited. However, for example, it is 0.01 or more and 0.8 or less, preferably 0.05 or more and 0.6 or less, more preferably 0.1 or more and 0.5 or less, further preferably 0.15 or more and 0.4 or less, and 0. .2 or more and 0.3 or less may be even more preferable.
  • the molar ratio ((I + II) / (Li + I + II)) of the total content of the first substituent and the second substituted element to the total content of lithium, the first substituted element and the second substituted element in the oxide is particularly high. Although not limited, for example, 0.05 or more and 0.3 or less is preferable, 0.1 or more and 0.2 or less is more preferable, and 0.14 or more and 0.16 or less is further preferable.
  • the molar ratio ((I + II) / (Li + I + II)) serves as a guide for the content of the first and second substituents on Li 2O , and the molar ratio ((I + II) / (Li + I + II)) is in the above range. Therefore, the Coulomb efficiency is further increased, and it becomes easier to maintain the Coulomb efficiency when charging and discharging are repeated.
  • the oxide may contain elements other than lithium, oxygen, a first-substituted element and a second-substituted element. However, the molar ratio of the contents of the other elements to the total content of all the elements constituting the oxide is preferably 0.1 or less, more preferably 0.01 or less.
  • the oxide may be substantially composed of lithium, oxygen, a first-substituted element and a second-substituted element. Since the oxide is substantially composed of lithium, oxygen, a first-substituted element and a second-substituted element, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained. ..
  • the oxygen content in the above oxide is not particularly limited, and is usually determined from the composition ratio of lithium, the first substituted element, the second substituted element, etc., the valence of these elements, and the like. However, it may be an oxide with insufficient oxygen or excess oxygen in the stoichiometric ratio.
  • the composition ratio of the oxide in the present specification means the composition ratio of the oxide that has not been charged and discharged, or the oxide that has been completely discharged by the following method.
  • the non-aqueous electrolyte power storage element is constantly charged with a current of 0.05 C until the charge end voltage at the time of normal use is reached, and the state is fully charged. After a 30-minute pause, a constant current discharge is performed with a current of 0.05 C to the lower limit voltage during normal use.
  • Disassemble take out the positive electrode, assemble a test battery with a metal lithium electrode as the counter electrode, and perform constant current discharge with a current of 10 mA per 1 g of the positive electrode mixture until the voltage between terminals reaches 1.5 V, and the positive electrode is in a completely discharged state.
  • the normal use is a case where the non-aqueous electrolyte storage element is used by adopting the charge / discharge conditions recommended or specified for the non-aqueous electrolyte storage element, and the non-aqueous electrolyte power storage element is used.
  • a charger for this purpose it means a case where the charger is applied to use the non-aqueous electrolyte power storage element.
  • the composition formula of the oxide is preferably represented by the following formula (1).
  • M is a first substitution element.
  • A is a second substitution element.
  • x, y and z satisfy the following formulas (a) to (c). 0 ⁇ x ⁇ 1 ... (a) 0 ⁇ y ⁇ 1 ... (b) x + y ⁇ z ⁇ 1 ... (c)
  • M in the above formula (1) is preferably Co, Fe, Cu, Mn, Ni, Cr or a combination thereof, and Co is more preferable.
  • a in the above formula (1) is preferably B, C, Mg, Si, P, Ti, Ga, Sn or a combination thereof.
  • the x in the above formula (1) is related to the content of the first substituent added to Li 2 O and satisfies the above formula (a).
  • x is preferably 0.01 or more and 0.5 or less, more preferably 0.03 or more and 0.3 or less, further preferably 0.05 or more and 0.2 or less, and further preferably 0.06 or more and 0.15 or less. , 0.08 or more and 0.12 or less is particularly preferable.
  • Y in the above formula (1) is related to the content of the second substituent added to Li 2 O and satisfies the above formula (b).
  • y is preferably 0.001 or more and 0.5 or less, more preferably 0.005 or more and 0.2 or less, further preferably 0.01 or more and 0.1 or less, and particularly preferably 0.02 or more and 0.04 or less.
  • Z in the above formula (1) is related to the Li content and satisfies the above formula (c).
  • z can be determined by the valences of the first and second substitution elements and the like.
  • z is preferably 0.1 or more and 0.5 or less, more preferably 0.2 or more and 0.4 or less, further preferably 0.26 or more and 0.32 or less, and particularly preferably 0.27 or more and 0.30 or less.
  • x and y of the above formula (1) satisfy the following formula (d). 0.01 ⁇ y / (x + y) ⁇ 0.8 ... (d) Y / (x + y) in the above formula (d) is the molar ratio of the content of the second substituent to the total content of the first substituted element and the second substituted element in the positive electrode active material (II / (I + II)). Is. y / (x + y) is more preferably 0.05 or more and 0.6 or less, further preferably 0.1 or more and 0.5 or less, further preferably 0.15 or more and 0.4 or less, and 0.2 or more and 0. In some cases, 3 or less is even more preferable. By setting y / (x + y) within the above range, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained.
  • the half width of the diffraction peak at a diffraction angle 2 ⁇ near 33 ° is preferably 0.3 ° or more, and 0.5 °. ° or more is more preferable, and 0.6 ° or more is further preferable.
  • the full width at half maximum of the diffraction peak near the diffraction angle 2 ⁇ is 33 ° or more, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained.
  • the half-value width of such a diffraction peak tends to be large.
  • the half width of the diffraction peak in which the diffraction angle 2 ⁇ is around 33 ° may be, for example, 5 ° or less, 3 ° or less, or 2 ° or less.
  • the positive electrode active material (A) may contain components other than the above oxides. However, the content of the oxide in the positive electrode active material (A) is preferably 50% by mass or more, more preferably 90% by mass or more, still more preferably 99% by mass or more.
  • the positive electrode active material (B) contains a first substituent, a second substituted element and lithium selected by using the method for selecting a substituent according to one embodiment of the present invention. Moreover, it contains an oxide having an inverted fluorite-type crystal structure, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0. It is a positive electrode active material having a value of .53 and a predetermined value of the abundance ratio under the condition B of 0.11.
  • the positive electrode active material (B) has a high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency is likely to be maintained even after repeated charging and discharging.
  • the specific form and suitable form of the oxide or the like contained in the positive electrode active material (B) are the same as those of the oxide or the like contained in the positive electrode active material (A).
  • the positive electrode active material (A) and the positive electrode active material (B) according to the embodiment of the present invention are produced, for example, by the following methods (A) to (C) for producing the positive electrode active material according to the embodiment of the present invention. be able to.
  • the method (A) for producing a positive electrode active material according to an embodiment of the present invention is a positive electrode activity containing lithium, a first-substituted element and a second-substituted element, and an oxide having an inverted fluorite-type crystal structure.
  • a method for producing a substance, comprising treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to an embodiment of the present invention.
  • the method for producing a positive electrode active material (B) according to another embodiment of the present invention which is a production method that embodies the method for producing a positive electrode active material (A), is a substitution element according to an embodiment of the present invention.
  • the combination of the first substitution element and the second substitution element is selected by the selection method (selection step), and the material containing lithium, oxygen, the first substitution element and the second substitution element is subjected to the mechanochemical method. (Processing process) is provided.
  • the positive electrode active material can also be manufactured by a manufacturing method that does not include the above-mentioned selection step.
  • the method (C) for producing a positive electrode active material according to another embodiment of the present invention which is such a production method, contains lithium, a first-substituted element and a second-substituted element, and has an inverted fluorite-type crystal structure.
  • a method for producing a positive electrode active material containing an oxide which comprises treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method (treatment step).
  • the first substitution element is an element other than technetium and tungsten, which belongs to any of the 6th to 11th groups
  • the second substitution element is the 2nd to 5th group and the 12th to 16th group.
  • a combination of the first substitution element and the second substitution element, which are elements other than nitrogen, oxygen, sulfur and selenium, which belong to any of the above, and the calculation result based on the first principle calculation satisfies the following conditions a and b.
  • Condition a The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more.
  • Condition b The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  • Specific examples and suitable examples of the first-substituted element and the second-substituted element contained in the material selected in these production methods or subjected to the treatment by the mechanochemical method are the positive electrode active materials according to the embodiment of the present invention. It is the same as the specific example and the preferable example of the 1st substitution element and the 2nd substitution element contained in the oxide contained in (A). Further, specific examples and suitable examples of the positive electrode active material produced by these production methods are the same as the specific examples and suitable examples of the positive electrode active material (A) according to the embodiment of the present invention.
  • the mechanochemical method (also referred to as mechanochemical treatment) is a synthetic method using a mechanochemical reaction.
  • the mechanochemical reaction refers to a chemical reaction such as a crystallization reaction, a solid solution reaction, or a phase transition reaction that utilizes high energy locally generated by mechanical energy such as friction and compression in the crushing process of a solid substance.
  • the treatment by the mechanochemical method causes a reaction in which the first-substituted element and the second-substituted element are dissolved in the crystal structure of Li 2O .
  • Examples of the apparatus for processing by the mechanochemical method include crushing / dispersing machines such as ball mills, bead mills, vibration mills, turbo mills, mechanofusions, and disc mills. Of these, a ball mill is preferable.
  • balls and mill containers used in the ball mill those made of tungsten carbide (WC), those made of zirconium oxide (ZrO 2 ), and the like can be preferably used.
  • the mill rotation speed during processing can be, for example, 100 rpm or more and 1,000 rpm or less.
  • the processing time can be, for example, 0.1 hour or more and 100 hours or less.
  • this treatment can be carried out in an atmosphere of an inert gas such as argon or an atmosphere of an active gas such as air, but it is preferably carried out in an atmosphere of an inert gas.
  • the inert gas refers to a gas that is inert to the material to be subjected to the ball mill treatment and the obtained positive electrode active material.
  • the positive electrode active material obtained by the method for producing a positive electrode active material (A) or the method for producing a positive electrode active material (B) according to an embodiment of the present invention also preferably has an inverted fluorite-type crystal structure.
  • it can be obtained by treating with a mechanochemical method as in the method for producing a positive electrode active material according to an embodiment of the present invention (B) or the method for producing a positive electrode active material according to an embodiment of the present invention (C).
  • the positive electrode active material to be obtained tends to have a large half-value width of a diffraction peak near a diffraction angle of 2 ⁇ of 33 °, which is 0.3 ° or more.
  • an oxide containing at least one of lithium, a first substitution element and a second substitution element is preferably used.
  • a compound containing at least one of lithium other than an oxide, a first-substituted element and a second-substituted element, or a simple substance of these elements can also be used.
  • Lithium, oxygen, the first substitution element and the second substitution element may be contained in the material composed of one kind or two or more kinds of compounds.
  • Suitable materials to be subjected to the treatment by the mechanochemical method include ( ⁇ ) a mixture containing a lithium transition metal composite oxide containing a first substituent and a compound containing a second substituent, and ( ⁇ ) a first substitution.
  • Examples include lithium transition metal composite oxides containing elements and second substituents. These materials may further contain other oxides (Li 2 O, etc.) and the like.
  • Examples of the oxide of lithium include Li 2 O.
  • Examples of the oxide of the first substituent include CoO, Co3O4 , Fe2O3 , MnO2 , NiO, Cu2O , CuO and the like.
  • Examples of the oxide or composite oxide of the second substitution element include B2 O 3 , MgO, Al 2 SiO 5 and the like.
  • Oxides containing lithium and the primary substituent include Li 6 CoO 4 , Li 5 CrO 4 , Li 5 FeO 4 , Li 6 NiO 4 , and Li 6 CuO. 4 , Li 6 MnO 4 , LiCoO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiFeO 2 , and the like.
  • the lithium transition metal composite oxide containing these first substituents may have an inverted fluorite-type crystal structure or may have another crystal structure.
  • These lithium transition metal composite oxides can be obtained by mixing, for example, Li 2O and an oxide of a first substituent such as CoO at a predetermined ratio and firing in a nitrogen atmosphere, an air atmosphere, or the like. Can be done.
  • Compounds containing lithium and the second substituent include Li 3 BO 3 , Li 4 B 2 O 5 , Li 6 B 4 O 9 , Li BO 2 , LiB 4 O 7 , aLi 2 O and bB 2 O 3 (a, b is an arbitrary rational number), Li 4 CO 4 , Li 2 MgO 2 , Li 4 SiO 4 , Li 3 PO 4 , Li 2 TiO 3 , Li 5 GaO 4 , Li 4 SnO 4 , Li 8 SiO 6 , LiSi 2 BO 6 , LiSiBO 4 , Li 2 TiSiO 5 and the like can be mentioned. These compounds may be crystalline, amorphous, glassy or the like. Each of the above compounds can be obtained by mixing, for example, a compound containing a second substituent such as Li 2 O and B 2 O 3 at a predetermined ratio and firing in a nitrogen atmosphere.
  • a compound containing a second substituent such as Li 2 O and B 2 O 3 at a predetermined ratio and firing in
  • Lithium transition metal composite oxides containing the first and second substituents include Li 5.5 Co 0.5 B 0.5 O 4 , Li 5.8 Co 0.8 B 0.2 O 4 and the like.
  • a metal composite oxide can be mentioned.
  • the lithium transition metal composite oxide containing the first substitution element and the second substitution element can be obtained by a known method such as a calcination method.
  • the crystal structure of these lithium transition metal composite oxides is not particularly limited, and may be, for example, a crystal structure that can be attributed to the space group P42 / nmc, a crystal structure that can be attributed to the space group Pmmn, or the like, and a plurality of crystal structures. May include. Further, these lithium transition metal composite oxides may contain amorphous or glassy substances in addition to crystalline substances.
  • the positive electrode according to the embodiment of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing the above-mentioned positive electrode active material (A) or positive electrode active material (B).
  • the positive electrode has a positive electrode base material and a positive electrode active material layer arranged directly on the positive electrode base material or via an intermediate layer.
  • the positive electrode base material has conductivity. "Having conductivity” means that the volume resistivity measured according to JIS-H-0505 (1975) is 107 ⁇ ⁇ cm or less, and “non-conductive” means. It means that the volume resistivity is more than 107 ⁇ ⁇ cm.
  • metals such as aluminum, titanium, tantalum, and stainless steel or alloys thereof are used. Among these, aluminum and aluminum alloys are preferable from the viewpoint of the balance between potential resistance, high conductivity and cost.
  • examples of the formation form of the positive electrode base material include foil, a vapor-deposited film, and the like, and foil is preferable from the viewpoint of cost. That is, aluminum foil is preferable as the positive electrode base material. Examples of aluminum or aluminum alloy include A1085P and A3003P specified in JIS-H-4000 (2014).
  • the average thickness of the positive electrode substrate is preferably 3 ⁇ m or more and 50 ⁇ m or less, more preferably 5 ⁇ m or more and 40 ⁇ m or less, further preferably 8 ⁇ m or more and 30 ⁇ m or less, and particularly preferably 10 ⁇ m or more and 25 ⁇ m or less.
  • the "average thickness" of the positive electrode base material and the negative electrode base material described later means a value obtained by dividing the punched mass when punching a base material having a predetermined area by the true density and the punched area of the base material.
  • the intermediate layer is a coating layer on the surface of the positive electrode base material, and contains conductive particles such as carbon particles to reduce the contact resistance between the positive electrode base material and the positive electrode active material layer.
  • the composition of the intermediate layer is not particularly limited, and can be formed by, for example, a composition containing a resin binder and conductive particles.
  • the positive electrode active material layer is formed from a so-called positive electrode mixture containing a positive electrode active material. Further, the positive electrode mixture forming the positive electrode active material layer contains optional components such as a conductive agent, a binder, a thickener, and a filler, if necessary.
  • the positive electrode active material includes the positive electrode active material (A) or the positive electrode active material (B) according to the above-described embodiment of the present invention.
  • the positive electrode active material may contain a known positive electrode active material other than the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention.
  • the content of the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention in the positive electrode active material layer is preferably more than 10% by mass, more preferably 30% by mass or more, and more preferably 50% by mass. The above is more preferable, and 70% by mass or more is particularly preferable.
  • the content of the positive electrode active material (A) or the positive electrode active material (B) in the positive electrode active material layer is 99% by mass or less, 98% by mass or less, 90% by mass or less, or 80. It may be mass% or less.
  • the conductive agent is not particularly limited as long as it is a conductive material.
  • a conductive agent include carbonaceous materials; metals; conductive ceramics and the like.
  • carbonaceous materials include graphite and carbon black.
  • Examples of the type of carbon black include furnace black, acetylene black, and ketjen black. Among these, carbonaceous materials are preferable from the viewpoint of conductivity and coatability. Of these, acetylene black and ketjen black are preferable.
  • Examples of the shape of the conductive agent include powder, sheet, and fibrous.
  • the positive electrode active material and the conductive agent may be combined.
  • Examples of the method of compositing include a method of mechanically milling a mixture containing a positive electrode active material and a conductive agent, which will be described later.
  • the content of the conductive agent in the positive electrode active material layer is preferably 1% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and further preferably 5% by mass or more or 10% by mass or more. ..
  • the energy density of the power storage element can be increased.
  • binder examples include fluororesins (polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.), thermoplastic resins such as polyethylene, polypropylene, and polyimide; ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, and styrene. Elastomers such as butadiene rubber (SBR) and fluororubber; polysaccharide polymers and the like can be mentioned.
  • fluororesins polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.
  • thermoplastic resins such as polyethylene, polypropylene, and polyimide
  • EPDM ethylene-propylene-diene rubber
  • SBR butadiene rubber
  • fluororubber polysaccharide polymers and the like can be mentioned.
  • the content of the binder in the positive electrode active material layer is preferably 1% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 9% by mass or less.
  • the thickener examples include polysaccharide polymers such as carboxymethyl cellulose (CMC) and methyl cellulose.
  • CMC carboxymethyl cellulose
  • methyl cellulose examples include polysaccharide polymers such as carboxymethyl cellulose (CMC) and methyl cellulose.
  • Fillers include polyolefins such as polypropylene and polyethylene, silicon dioxide, aluminum oxide, titanium dioxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide, inorganic oxides such as aluminosilicate, magnesium hydroxide, calcium hydroxide, and water.
  • Hydroxides such as aluminum oxide, carbonates such as calcium carbonate, sparingly soluble ion crystals such as calcium fluoride, barium fluoride, barium sulfate, nitrides such as aluminum nitride and silicon nitride, talc, montmorillonite, boehmite and zeolite.
  • Apatite Kaolin, Murite, Spinel, Olivin, Sericite, Bentonite, Mica and other mineral resource-derived substances or man-made products thereof.
  • the positive electrode active material layer is a typical non-metal element such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, Si, K, Ca, Zn, Ga, Ge, Sn, Sr, Typical metal elements such as Ba and transition metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Nb and W are used as positive electrode active materials, conductive agents, binders and thickeners. , May be contained as a component other than the filler.
  • the positive electrode according to the embodiment of the present invention can be manufactured by, for example, the following method. That is, the method for producing a positive electrode according to an embodiment of the present invention is the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention or the positive electrode active material according to the embodiment of the present invention. A positive electrode is produced by using the positive electrode active material obtained by any of the production methods (A) to (C).
  • the positive electrode can be produced, for example, by applying the positive electrode mixture paste directly to the positive electrode substrate or via an intermediate layer and drying it.
  • the positive electrode mixture paste contains each component constituting the positive electrode mixture, such as a positive electrode active material and optional components such as a conductive agent and a binder.
  • the positive electrode mixture paste may further contain a dispersion medium.
  • the positive electrode active material and the conductive agent are mixed, it is preferable to mechanically mill the mixture containing the positive electrode active material and the conductive agent.
  • the positive electrode active material according to the embodiment of the present invention is used, sufficient charge / discharge performance and the like are provided by performing the mechanical milling treatment in the state of a mixture containing the positive electrode active material and the conductive agent.
  • a positive electrode that can be used as a non-aqueous electrolyte power storage element can be manufactured with high certainty.
  • the mechanical milling process refers to a process of pulverizing, mixing, or compounding by applying mechanical energy such as impact, shear stress, and friction.
  • the device for performing the mechanical milling process include crushing / dispersing machines such as ball mills, bead mills, vibration mills, turbo mills, mechanofusions, and disc mills. Of these, a ball mill is preferable.
  • the balls and mill containers used in the ball mill those made of tungsten carbide (WC), those made of zirconium oxide (ZrO 2 ), and the like can be preferably used.
  • the mechanical milling treatment referred to here does not need to be accompanied by a mechanochemical reaction. It is presumed that such mechanical milling treatment composites the positive electrode active material and the conductive agent, and improves the electron conductivity.
  • the mill rotation speed during processing can be, for example, 100 rpm or more and 1,000 rpm or less.
  • the processing time can be, for example, 0.1 hour or more and 100 hours or less.
  • this treatment can be carried out in an atmosphere of an inert gas such as argon or an atmosphere of an active gas such as air, but it is preferably carried out in an atmosphere of an inert gas.
  • the non-aqueous electrolyte power storage element has a positive electrode, a negative electrode, and a non-aqueous electrolyte.
  • a non-aqueous electrolyte secondary battery (hereinafter, also simply referred to as “secondary battery”) will be described.
  • the positive electrode and the negative electrode usually form an electrode body that is alternately superposed by laminating or winding through a separator.
  • the electrode body is housed in a container, and the container is filled with a non-aqueous electrolyte.
  • the non-aqueous electrolyte is interposed between the positive electrode and the negative electrode.
  • a known metal container, resin container, or the like usually used as a container for a secondary battery can be used.
  • the positive electrode provided in the secondary battery is the positive electrode according to the above-described embodiment of the present invention.
  • the negative electrode has a negative electrode base material and a negative electrode active material layer arranged directly on the negative electrode base material or via an intermediate layer.
  • the intermediate layer may have the same structure as the intermediate layer of the positive electrode.
  • the negative electrode base material may have the same configuration as the positive electrode base material, but as the material, a metal such as copper, nickel, stainless steel, nickel-plated steel or an alloy thereof is used, and copper or a copper alloy is used. preferable. That is, a copper foil is preferable as the negative electrode base material. Examples of the copper foil include rolled copper foil and electrolytic copper foil.
  • the average thickness of the negative electrode substrate is preferably 2 ⁇ m or more and 35 ⁇ m or less, more preferably 3 ⁇ m or more and 30 ⁇ m or less, further preferably 4 ⁇ m or more and 25 ⁇ m or less, and particularly preferably 5 ⁇ m or more and 20 ⁇ m or less.
  • the negative electrode active material layer is generally formed of a so-called negative electrode mixture containing a negative electrode active material. Further, the negative electrode mixture forming the negative electrode active material layer contains optional components such as a conductive agent, a binder, a thickener, and a filler, if necessary. As any component such as a conductive agent, a binder, a thickener, and a filler, the same one as that of the positive electrode active material layer can be used.
  • the negative electrode active material layer may be a layer substantially composed of only a negative electrode active material such as metallic Li.
  • the negative electrode active material layer includes typical non-metal elements such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, K, Ca, Zn, Ga, Ge, Sn, Sr, Ba and the like.
  • Typical metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Ta, Hf, Nb, W, etc. It may be contained as a component other than the thickener and the filler.
  • the negative electrode active material can be appropriately selected from known negative electrode active materials.
  • a material capable of occluding and releasing lithium ions is usually used.
  • the negative electrode active material include metal Li; metal or semi-metal such as Si and Sn; metal oxide or semi-metal oxide such as Si oxide, Ti oxide and Sn oxide; Li 4 Ti 5 O 12 ; Titanium-containing oxides such as LiTIO 2 and TiNb 2O 7 ; polyphosphate compounds; silicon carbide; carbon materials such as graphite (graphite) and non-graphitric carbon (easy graphitable carbon or non-graphitizable carbon) can be mentioned. Be done. Among these materials, graphite and non-graphitic carbon are preferable. In the negative electrode active material layer, one of these materials may be used alone, or two or more of them may be mixed and used.
  • Graphite refers to a carbon material having an average lattice spacing (d 002 ) of (002) planes determined by X-ray diffraction method before charging / discharging or in a discharged state of 0.33 nm or more and less than 0.34 nm.
  • Examples of graphite include natural graphite and artificial graphite. Artificial graphite is preferable from the viewpoint that a material having stable physical properties can be obtained.
  • Non-graphitic carbon refers to a carbon material having an average lattice spacing (d 002 ) of the (002) plane determined by the X-ray diffraction method before charging / discharging or in a discharged state of 0.34 nm or more and 0.42 nm or less. ..
  • Examples of non-graphitizable carbon include non-graphitizable carbon and easily graphitizable carbon.
  • the non-planar carbon include a resin-derived material, a petroleum pitch or a petroleum pitch-derived material, a petroleum coke or a petroleum coke-derived material, a plant-derived material, an alcohol-derived material, and the like.
  • the "discharged state" of the carbon material is a state in which the open circuit voltage is 0.7 V or more in a unipolar battery using a negative electrode containing a carbon material as a negative electrode active material as a working electrode and a metal Li as a counter electrode.
  • the open circuit voltage in the single pole battery is substantially equal to the potential of the negative electrode containing the carbon material with respect to the redox potential of Li. .. That is, the fact that the open circuit voltage in the single-pole battery is 0.7 V or more means that the carbon material, which is the negative electrode active material, sufficiently releases lithium ions that can be occluded and discharged by charging and discharging. ..
  • non-graphitizable carbon refers to a carbon material having d 002 of 0.36 nm or more and 0.42 nm or less.
  • the “graphitizable carbon” refers to a carbon material having d 002 of 0.34 nm or more and less than 0.36 nm.
  • the average particle size of the negative electrode active material can be, for example, 1 nm or more and 100 ⁇ m or less.
  • the average particle size thereof may be preferably 1 ⁇ m or more and 100 ⁇ m or less.
  • the negative electrode active material is a metal, a semi-metal, a metal oxide, a semi-metal oxide, a titanium-containing oxide, a polyphosphate compound or the like, the average particle size thereof may be preferably 1 nm or more and 1 ⁇ m or less.
  • the average particle size of the negative electrode active material By setting the average particle size of the negative electrode active material to be equal to or higher than the above lower limit, the production or handling of the negative electrode active material becomes easy. By setting the average particle size of the negative electrode active material to the above upper limit or less, the electron conductivity of the active material layer is improved. A crusher, a classifier, or the like is used to obtain a powder having a predetermined particle size.
  • the negative electrode active material is metallic Li
  • the form may be foil-shaped or plate-shaped.
  • the content of the negative electrode active material in the negative electrode active material layer is preferably 60% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 98% by mass or less, for example, when the negative electrode active material layer is formed of a negative electrode mixture. preferable.
  • the content of the negative electrode active material may be 99% by mass or more, or may be 100% by mass.
  • the separator can be appropriately selected from known separators.
  • a separator composed of only a base material layer a separator having a heat-resistant layer containing heat-resistant particles and a binder formed on one surface or both surfaces of the base material layer can be used.
  • the base material layer of the separator include woven fabrics, non-woven fabrics, and porous resin films. Among these, a porous resin film is preferable from the viewpoint of strength, and a non-woven fabric is preferable from the viewpoint of liquid retention of a non-aqueous electrolyte.
  • polyolefins such as polyethylene and polypropylene are preferable from the viewpoint of shutdown function, and polyimide and aramid are preferable from the viewpoint of oxidative decomposition resistance.
  • base material layer of the separator a material in which these resins are combined may be used.
  • the heat-resistant particles contained in the heat-resistant layer preferably have a mass loss of 5% or less when heated from room temperature to 500 ° C. in the atmosphere, and a mass loss of 5% when heated from room temperature to 800 ° C. in the atmosphere.
  • the following are more preferable.
  • Examples of the material whose mass reduction is equal to or less than a predetermined value include inorganic compounds.
  • Examples of the inorganic compound include oxides such as iron oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide and aluminosilicate; magnesium hydroxide, calcium hydroxide and water.
  • Hydroxides such as aluminum oxide; Nitridees such as aluminum nitride and silicon nitride; Carbonates such as calcium carbonate; Sulfates such as barium sulfate; Slowly soluble ion crystals such as calcium fluoride, barium fluoride and barium titanate Covalently bonded crystals such as silicon and diamond; talc, montmorillonite, boehmite, zeolite, apatite, kaolin, mulite, spinel, olivine, sericite, bentonite, mica and other mineral resource-derived substances or man-made products thereof. ..
  • the inorganic compound a simple substance or a complex of these substances may be used alone, or two or more kinds thereof may be mixed and used.
  • silicon oxide, aluminum oxide, or aluminosilicate is preferable from the viewpoint of safety of the power storage device.
  • the porosity of the separator is preferably 80% by volume or less from the viewpoint of strength, and preferably 20% by volume or more from the viewpoint of discharge performance.
  • the "porosity” is a value based on volume, and means a value measured by a mercury porosity meter.
  • a polymer gel composed of a polymer and a non-aqueous electrolyte may be used.
  • the polymer include polyacrylonitrile, polyethylene oxide, polypropylene oxide, polymethyl methacrylate, polyvinyl acetate, polyvinylpyrrolidone, polyvinylidene fluoride and the like.
  • the use of polymer gel has the effect of suppressing liquid leakage.
  • a polymer gel may be used in combination with a porous resin film or a non-woven fabric as described above.
  • Non-water electrolyte As the non-aqueous electrolyte, a known non-aqueous electrolyte can be appropriately selected. A non-aqueous electrolyte solution may be used as the non-aqueous electrolyte.
  • the non-aqueous electrolyte solution contains a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
  • the non-aqueous solvent can be appropriately selected from known non-aqueous solvents.
  • the non-aqueous solvent include cyclic carbonates, chain carbonates, carboxylic acid esters, phosphoric acid esters, sulfonic acid esters, ethers, amides, nitriles and the like.
  • a solvent in which some of the hydrogen atoms contained in these compounds are replaced with halogen may be used.
  • cyclic carbonate examples include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), vinyl ethylene carbonate (VEC), chloroethylene carbonate, fluoroethylene carbonate (FEC), and difluoroethylene carbonate.
  • EC ethylene carbonate
  • PC propylene carbonate
  • BC butylene carbonate
  • VC vinylene carbonate
  • VEC vinyl ethylene carbonate
  • FEC fluoroethylene carbonate
  • DFEC difluoroethylene carbonate
  • styrene carbonate 1-phenylvinylene carbonate
  • 1,2-diphenylvinylene carbonate and the like can be mentioned.
  • EC is preferable.
  • chain carbonate examples include diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), diphenyl carbonate, trifluoroethylmethyl carbonate, bis (trifluoroethyl) carbonate and the like.
  • DEC diethyl carbonate
  • DMC dimethyl carbonate
  • EMC ethylmethyl carbonate
  • diphenyl carbonate trifluoroethylmethyl carbonate
  • bis (trifluoroethyl) carbonate bis (trifluoroethyl) carbonate and the like.
  • DMC and EMC are preferable.
  • the cyclic carbonate and the chain carbonate are used as the non-aqueous solvent, and it is more preferable to use the cyclic carbonate and the chain carbonate in combination.
  • the cyclic carbonate By using the cyclic carbonate, the dissociation of the electrolyte salt can be promoted and the ionic conductivity of the non-aqueous electrolyte solution can be improved.
  • the chain carbonate By using the chain carbonate, the viscosity of the non-aqueous electrolytic solution can be kept low.
  • the volume ratio of the cyclic carbonate to the chain carbonate is preferably in the range of, for example, 5:95 to 50:50.
  • the electrolyte salt can be appropriately selected from known electrolyte salts.
  • Examples of the electrolyte salt include lithium salt, sodium salt, potassium salt, magnesium salt, onium salt and the like. Of these, lithium salts are preferred.
  • Lithium salts include inorganic lithium salts such as LiPF 6 , LiPO 2 F 2 , LiBF 4 , LiClO 4 , LiN (SO 2 F) 2 , LiSO 3 CF 3 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 ). C 2 F 5 ) 2 , LiN (SO 2 CF 3 ) (SO 2 C 4 F 9 ), LiC (SO 2 CF 3 ) 3 , LiC (SO 2 C 2 F 5 ) 3 and other halogenated hydrocarbon groups Examples thereof include lithium salts having. Among these, an inorganic lithium salt is preferable, and LiPF 6 is more preferable.
  • the content of the electrolyte salt in the non-aqueous electrolyte solution is preferably 0.1 mol / dm 3 or more and 2.5 mol / dm 3 or less, and more preferably 0.3 mol / dm 3 or more and 2.0 mol / dm 3 or less. , 0.5 mol / dm 3 or more and 1.7 mol / dm 3 or less is more preferable, and 0.7 mol / dm 3 or more and 1.5 mol / dm 3 or less is particularly preferable.
  • the non-aqueous electrolytic solution may contain an additive.
  • the additive include aromatic compounds such as biphenyl, alkyl biphenyl, terphenyl, and partially hydrides of turphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, and dibenzofuran; 2-fluorobiphenyl, o.
  • -Partial halides of the above aromatic compounds such as cyclohexylfluorobenzene and p-cyclohexylfluorobenzene; Halogenated anisole compounds; succinic anhydride, glutaric anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, cyclohexanedicarboxylic acid anhydride; ethylene sulfone, propylene sulfite, dimethyl sulfite, dimethyl sulfate, ethylene sulfate, Sulfone, dimethyl sulfone, diethyl sulfone, dimethyl sulfoxide, diethyl sulfoxide, tetramethylene sulfoxide, diphenyl sulfide, 4,4'-bis (2,2-dioxo-1,3,2-dioxathiolane), 4-methylsulfonyloxymethyl- Examples thereof
  • the content of the additive contained in the non-aqueous electrolytic solution is preferably 0.01% by mass or more and 10% by mass or less, and more preferably 0.1% by mass or more and 7% by mass or less with respect to the total mass of the non-aqueous electrolytic solution. , 0.2% by mass or more and 5% by mass or less is more preferable, and 0.3% by mass or more and 3% by mass or less is particularly preferable.
  • non-aqueous electrolyte a solid electrolyte may be used, or a non-aqueous electrolyte solution and a solid electrolyte may be used in combination.
  • the solid electrolyte can be selected from any material having lithium ion conductivity and being solid at room temperature (for example, 15 ° C to 25 ° C).
  • the solid electrolyte include a sulfide solid electrolyte, an oxide solid electrolyte, an oxynitride solid electrolyte, a polymer solid electrolyte and the like.
  • lithium ion secondary battery examples include Li 2 SP 2 S 5 , Li I-Li 2 SP 2 S 5 , Li 10 GeP 2 S 12 , and the like as the sulfide solid electrolyte.
  • the non-aqueous electrolyte power storage element since the positive electrode active material according to the embodiment of the present invention is used for the positive electrode, the coulomb efficiency is high even when the amount of charging electricity is relatively large. This high Coulomb efficiency is likely to be maintained even after repeated discharges. Therefore, the non-aqueous electrolyte power storage element can be suitably used in a usage mode in which the amount of charging electricity is large.
  • the amount of charging electricity per mass of the positive electrode active material in normal use is preferably 300 mAh / g or more and 600 mAh / g or less, and 400 mAh / g or more and 500 mAh / g or less. Is more preferable.
  • the non-aqueous electrolyte power storage element according to the embodiment of the present invention has high Coulomb efficiency even when the charging electricity amount is relatively large. Therefore, by setting the charging electricity amount to the above lower limit or more, the effective electricity amount is increased. can do. On the other hand, by setting the amount of charging electricity to be equal to or less than the above upper limit, it becomes easier to maintain the Coulomb efficiency when charging and discharging are repeated.
  • the amount of charging electricity is a value measured by the following method. First, the power storage element is constantly discharged to the lower limit voltage during normal use with a current of 0.05 C. After a 30-minute pause, the power storage element is charged with a current of 0.05 C at a constant current until it reaches the end-of-charge voltage during normal use, and is in a fully charged state. The amount of electricity charged at this time is defined as the amount of electricity charged.
  • the shape of the non-aqueous electrolyte power storage element of the present embodiment is not particularly limited, and examples thereof include a cylindrical battery, a square battery, a flat battery, a coin battery, and a button battery.
  • FIG. 1 shows a non-aqueous electrolyte power storage element 1 as an example of a square battery.
  • the figure is a perspective view of the inside of the container.
  • the electrode body 2 having the positive electrode and the negative electrode wound around the separator is housed in the square container 3.
  • the positive electrode is electrically connected to the positive electrode terminal 4 via the positive electrode lead 41.
  • the negative electrode is electrically connected to the negative electrode terminal 5 via the negative electrode lead 51.
  • the power storage device includes a plurality of non-aqueous electrolyte power storage elements, and includes one or more non-water electrolyte power storage elements according to one embodiment of the present invention.
  • the non-aqueous electrolyte power storage element of the present embodiment is a power source for automobiles such as an electric vehicle (EV), a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV), a power source for electronic devices such as a personal computer and a communication terminal, or a power source.
  • EV electric vehicle
  • HEV hybrid vehicle
  • PHEV plug-in hybrid vehicle
  • a power storage unit composed of a plurality of non-aqueous electrolyte power storage elements 1 can be mounted on a storage power source or the like as a power storage device further assembled.
  • the technique according to the embodiment of the present invention may be applied to at least one non-aqueous electrolyte power storage element included in the power storage device.
  • FIG. 2 shows an example of a power storage device 30 in which a power storage unit 20 in which two or more electrically connected non-aqueous electrolyte power storage elements 1 are assembled is further assembled.
  • the power storage device 30 includes a bus bar (not shown) for electrically connecting two or more non-aqueous electrolyte power storage elements 1, a bus bar (not shown) for electrically connecting two or more power storage units 20 and the like. May be good.
  • the power storage unit 20 or the power storage device 30 may include a condition monitoring device (not shown) for monitoring the state of one or more non-aqueous electrolyte power storage elements.
  • the non-aqueous electrolyte power storage device can be manufactured by using the positive electrode according to the embodiment of the present invention.
  • the method for manufacturing a non-aqueous electrolyte power storage element according to an embodiment of the present invention includes a method for manufacturing a positive electrode according to an embodiment of the present invention.
  • the method for manufacturing the non-aqueous electrolyte power storage element includes producing the above-mentioned positive electrode, producing a negative electrode, preparing a non-aqueous electrolyte, and laminating or winding a positive electrode and a negative electrode via a separator. It comprises forming the electrode bodies alternately superimposed, accommodating the positive electrode body and the negative electrode body (electrode body) in a container, and injecting the non-aqueous electrolyte into the container. After the injection, the non-aqueous electrolyte power storage element can be obtained by sealing the injection port.
  • the present invention is not limited to the above embodiment, and various modifications may be made without departing from the gist of the present invention.
  • the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment or a well-known technique.
  • some of the configurations of certain embodiments can be deleted.
  • a well-known technique can be added to the configuration of a certain embodiment.
  • non-aqueous electrolyte storage element is used as a chargeable / dischargeable non-aqueous electrolyte secondary battery (for example, a lithium ion secondary battery) has been described.
  • the capacity etc. are arbitrary.
  • the non-aqueous electrolyte storage element of the present invention can also be applied to capacitors such as various non-aqueous electrolyte secondary batteries, electric double layer capacitors, and lithium ion capacitors.
  • Example 1 Selection of Substituent Element
  • an oxide No. 1 having each composition shown in Table 2 and having a fluorite-type crystal structure. 1 to No. 21 was selected and the calculation was performed.
  • VASP Vienna Ab-initio Simulation Package
  • the predetermined charging state under the above-mentioned conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the condition A is 0. It was set to .53, and the predetermined value of the abundance ratio under the condition B was set to 0.11. That is, the condition (a) and the condition (b) satisfied by the "positive electrode active material (A)" according to the embodiment of the present invention are adopted. Further, the specific conditions relating to the condition (a) and the condition (b) are as described above as the conditions relating to the "positive electrode active material (A)" according to the embodiment of the present invention. Table 2 shows the calculation results related to the conditions a and b, and the results of whether or not these conditions are satisfied (pass / fail). In Table 2, "P” indicates that each condition is satisfied, and “F” indicates that each condition is not satisfied.
  • the first substitution element is Co and the second substitution elements are B and Si. , C, Ga, Mg, P, Ti or Sn (No. 3, 4, 6, 8 to 13 and 18), and the first substitution element is Fe, Ni or Cu and the second substitution element is It can be judged that the combination (No. 19 to 21) of B is good.
  • the following is actually the above No. Using each of the oxides 1 and 2 as a comparative example, the above No. Each oxide of 3, 8 to 10 was actually synthesized and evaluated as an example. That is, the combination of Co and B, Si or Ga is selected as the combination of the first substitution element and the second substitution element by the above-mentioned "method for selecting a substitution element" according to the embodiment of the present invention. The actual evaluation was performed.
  • Example 2 Production of positive electrode active material After mixing the obtained Li 6 CoO 4 (1.6805 g), the obtained Li 3 BO 3 (0.2323 g), and Li 2 O (0.0872 g), It was put into a WC mill container together with a tungsten carbide (WC) ball under an argon atmosphere, and treated with a planetary ball mill device (“pulveristte 5” manufactured by FRITSCH) at a rotation speed of 400 rpm for 2 hours. By such treatment by the mechanochemical method, the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) of Example 2 was obtained.
  • Example 3 to 5 Comparative Examples 1 and 2
  • the positive electrode active materials of Examples 3 to 5 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 2 except that the materials used were as shown in Table 3.
  • Table 3 also shows the composition formulas of the obtained positive electrode active material.
  • FIG. 3 shows an X-ray diffraction diagram of each positive electrode active material (oxide) of Examples 2 and 3 and Comparative Examples 1 and 2
  • FIG. 4 shows an X-ray diffraction of each positive electrode active material (oxide) of Examples 4 and 5.
  • Table 3 shows the half-value width of the diffraction peak in which the diffraction angle 2 ⁇ in the positive electrode active materials (oxides) of Examples 2 to 5 and Comparative Examples 1 and 2 obtained from the X-ray diffraction measurement is around 33 °.
  • LiPF 6 was dissolved in a non-aqueous solvent in which EC, DMC and EMC were mixed at a volume ratio of 30:35:35 at a concentration of 1 mol / dm 3 to prepare a non-aqueous electrolyte.
  • EC, DMC and EMC were mixed at a volume ratio of 30:35:35 at a concentration of 1 mol / dm 3 to prepare a non-aqueous electrolyte.
  • metallic lithium with a diameter of 22 mm ⁇ as the negative electrode
  • laminating them via a polypropylene separator and storing them in a container and injecting 300 ⁇ L of the prepared non-aqueous electrolyte into a non-aqueous electrolyte storage element (evaluation cell).
  • the evaluation cell was prepared in an argon atmosphere.
  • the discharge was terminated when the upper limit electric amount of 400 mAh / g or the lower limit voltage of 1.5 V per mass of the positive electrode active material was reached.
  • the charge / discharge cycle was repeated until the Coulomb efficiency fell below 90%.
  • Table 4 shows the charge electricity amount and the Coulomb efficiency in the first cycle, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more is maintained.
  • Example 2 For the positive electrode active material (oxide) of Example 2, the same evaluation cells as above (Examples 13 to 15) are separately prepared, and the upper limit per mass of the positive electrode active material for charging and discharging in an environment of 25 ° C. The same charge / discharge tests as above were performed except that the amount of electricity was changed to 450 mAh / g, 500 mAh / g, and 550 mAh / g, respectively. Table 6 shows the amount of electricity charged and the Coulomb efficiency in the first cycle in each evaluation cell, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained.
  • Example 16 For the positive electrode active material (oxide) of Example 4, an evaluation cell (Example 16) similar to the above is separately prepared, and the upper limit electric amount per mass of the positive electrode active material for charging and discharging in an environment of 25 ° C. The same charge / discharge test as above was performed except that the value was changed to 500 mAh / g. Table 7 shows the amount of electricity charged and the Coulomb efficiency in the first cycle in the evaluation cell, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained.
  • Example 17 and Comparative Example 7 For the positive electrode active materials (oxides) of Example 2 and Comparative Example 2, evaluation cells for charging gas swelling test (Example 17 and Comparative Example 7) were separately prepared. Using the obtained positive electrode, 25 mm square metallic lithium was used as the negative electrode, laminated via a polypropylene separator, and sealed with an exterior body made of a metal resin composite film. An evaluation cell (storage element) is formed by enclosing 300 ⁇ L of a non-aqueous electrolyte prepared in the same manner as in the above charge / discharge test, and the following charging test (charging gas swelling test) is performed in a constant temperature bath under the atmosphere at 25 ° C. ) Was performed.
  • FIG. 6 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell (Example 17) using the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) of Example 2.
  • 5 shows changes in the positive electrode potential and the amount of cell swelling during charging of the evaluation cell (Comparative Example 7) using the positive electrode active material (Li 1.389 Co 0.139 Al 0.111 O) of Comparative Example 2. The graph is shown in FIG.
  • Example 1 it can be determined in Example 1 that it is a suitable combination of substitution elements according to the method for selecting a substitution element according to the embodiment of the present invention, and the selected first substitution element is Co and the second substitution element.
  • the Coulomb efficiency was high, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained was also large.
  • Table 5 when the amount of charging electricity is larger, it can be determined that the combination of the substitution elements is suitable by the method of selecting the substitution element according to the embodiment of the present invention in Example 1, and the first selection is made.
  • Examples 10 to 12 using the positive electrode active material in which the substitution element is Co and the second substitution element is B or Si the effect of high Coulomb efficiency was remarkably shown. Further, as shown in Tables 6 and 7, it can be determined that the combination of the substitution elements is suitable by the method of selecting the substitution element according to the embodiment of the present invention in Example 1, and the selected first substitution element is Co.
  • a positive electrode active material Li 1.444 Co 0.194 B 0.056 O or Li 1.389 Co 0.194 Si 0.056 O
  • the second substitution element is B or Si
  • Example 17 using the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) obtained in Example 2 is Compared with Comparative Example 7 (FIG. 6) using the positive electrode active material (Li 1.389 Co 0.139 Al 0.111 O) obtained in Comparative Example 2, charging electricity until gas swelling started. The amount was large, and gas swelling during charging was suppressed.
  • the positive electrode active material obtained in Example 2 is unlikely to undergo irreversible changes due to charging such as oxygen release.
  • the positive electrode active material Li 1. When 444 Co 0.194 B 0.056 O) is used, it can be said that the stability of oxygen in the crystal structure is high. Further, in the positive electrode active material of each example, it is presumed that such high structural stability improves high Coulomb efficiency and its maintainability.
  • the present invention can be applied to personal computers, electronic devices such as communication terminals, non-aqueous electrolyte power storage elements used as power sources for automobiles, power storage devices, and positive electrodes and positive electrode active materials provided therein.
  • Non-aqueous electrolyte power storage element 1
  • Electrode body 3
  • Container 4
  • Positive terminal 4
  • Negative terminal 51
  • Negative lead 20
  • Power storage unit 30
  • Power storage device

Abstract

The present invention according to one aspect is a method for selecting a first substitution element and a second substitution element for a positive electrode active material that includes lithium, a first substitution element, and a second substation element, and contains an oxide having an antifluorite crystal structure, wherein the method for selecting substitution elements comprises selecting, as the first substitution element and the second substitution element, a combination for which the calculation result based on a first principle calculation fulfills condition A and condition B below:　A) the ratio in which a first substitution element for which the oxygen coordination number is 4 is present with respect to all the first substitution elements for which the oxide is in a prescribed state of charge is equal to or greater than a prescribed value B) the ratio in which an oxygen having a charge of greater than –0.5 is present with respect to all oxygens in the oxide having a prescribed state of charge is equal to or less than a prescribed value.

Description

置換元素の選択方法、正極活物質、正極、非水電解質蓄電素子、蓄電装置、正極活物質の製造方法、正極の製造方法、及び非水電解質蓄電素子の製造方法Method for selecting a substitution element, positive electrode active material, positive electrode, non-aqueous electrolyte power storage element, power storage device, positive electrode active material manufacturing method, positive electrode manufacturing method, and non-aqueous electrolyte power storage element manufacturing method.
　本発明は、置換元素の選択方法、正極活物質、正極、非水電解質蓄電素子、蓄電装置、正極活物質の製造方法、正極の製造方法、及び非水電解質蓄電素子の製造方法に関する。 The present invention relates to a method for selecting a substitution element, a positive electrode active material, a positive electrode, a non-aqueous electrolyte power storage element, a power storage device, a positive electrode active material manufacturing method, a positive electrode manufacturing method, and a non-aqueous electrolyte power storage element manufacturing method.
　リチウムイオン二次電池に代表される非水電解質二次電池は、エネルギー密度の高さから、パーソナルコンピュータ、通信端末等の電子機器、自動車等に多用されている。上記非水電解質二次電池は、一般的には、セパレータで電気的に隔離された一対の電極と、この電極間に介在する非水電解質とを有し、両電極間でイオンの受け渡しを行うことで充放電するよう構成される。また、非水電解質二次電池以外の非水電解質蓄電素子として、リチウムイオンキャパシタや電気二重層キャパシタ等のキャパシタも広く普及している。 Non-aqueous electrolyte secondary batteries represented by lithium-ion secondary batteries are widely used in personal computers, electronic devices such as communication terminals, automobiles, etc. due to their high energy density. The non-aqueous electrolyte secondary battery generally has a pair of electrodes electrically separated by a separator and a non-aqueous electrolyte interposed between the electrodes, and transfers ions between the two electrodes. It is configured to charge and discharge. In addition, capacitors such as lithium ion capacitors and electric double layer capacitors are also widely used as non-aqueous electrolyte storage elements other than non-aqueous electrolyte secondary batteries.
　非水電解質蓄電素子の正極及び負極には、各種活物質が採用されており、正極活物質としては、様々な複合酸化物が広く用いられている。正極活物質の一つとして、Ｌｉ２ＯにＣｏ、Ｆｅ等の遷移金属元素を固溶させた遷移金属固溶金属酸化物が開発されている（特許文献１、２参照）。また、Ｌｉ２ＯにＣｏと共にＡｌ等の典型元素を固溶させた正極活物質も提案されている（特許文献３参照）。 Various active materials are used for the positive electrode and the negative electrode of the non-aqueous electrolyte power storage element, and various composite oxides are widely used as the positive electrode active material. As one of the positive electrode active materials, a transition metal solid-dissolved metal oxide in which a transition metal element such as Co or Fe is solid-dissolved in Li 2 O has been developed (see Patent Documents 1 and 2). Further, a positive electrode active material in which a typical element such as Al is dissolved in Li 2 O together with Co has also been proposed (see Patent Document 3).
特開２０１５－１０７８９０号公報Japanese Unexamined Patent Publication No. 2015-107890 特開２０１５－３２５１５号公報JP-A-2015-32515 国際公開第２０１９／１６３４７６号International Publication No. 2019/163476
　上記のような従来のＬｉ２Ｏに１種又は複数種の元素が固溶された正極活物質は、Ｌｉ２Ｏに対して各種改善がなされているものの、充電電気量を大きくした場合、充電電気量に対する放電電気量の比、すなわちクーロン効率が低い。このように従来のＬｉ２Ｏに１種又は複数種の元素が固溶された正極活物質は、実効電気量が小さいという不都合を有する。ここで、Ｌｉ２Ｏに対して様々な元素を固溶させた何種類もの正極活物質を実際に合成し、これらの性能を全て評価することで、良好な性能を有する正極活物質を見つけ出すことは可能ではある。しかし、置換元素を２種用いて性能を改善しようとした場合、２種の置換元素の組み合わせは非常に多数になる。このため、このような正極活物質を何種類も合成して評価し、良好な性能を有する正極活物質を見つけ出すことは多くの時間とコストが必要となり、非常に非効率である。 Although the positive electrode active material in which one or more kinds of elements are solid-dissolved in the conventional Li 2 O as described above has been improved in various ways with respect to Li 2 O, it is charged when the amount of charging electricity is increased. The ratio of the amount of discharged electricity to the amount of electricity, that is, the Coulomb efficiency is low. As described above, the positive electrode active material in which one or more kinds of elements are solid-solved in the conventional Li 2 O has the disadvantage that the effective electric energy is small. Here, by actually synthesizing various kinds of positive electrode active materials in which various elements are dissolved in Li 2 O and evaluating all of these performances, it is possible to find a positive electrode active material having good performance. Is possible. However, when trying to improve the performance by using two kinds of substitution elements, the number of combinations of the two kinds of substitution elements becomes very large. Therefore, it is very inefficient because it takes a lot of time and cost to synthesize and evaluate many kinds of such positive electrode active materials and find a positive electrode active material having good performance.
　本発明は、以上のような事情に基づいてなされたものであり、その目的は、充電電気量が比較的大きい場合（例えば、正極活物質の質量あたりの充電電気量が４００ｍＡｈ／ｇ以上の場合）もクーロン効率が高い正極活物質に含有される酸化物に好適な置換元素を効率的に選択する方法、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質、このような正極活物質を有する正極、非水電解質蓄電素子及び蓄電装置、上記正極活物質の製造方法、上記正極の製造方法、並びに上記非水電解質蓄電素子の製造方法を提供することである。 The present invention has been made based on the above circumstances, and an object thereof is when the amount of electricity for charging is relatively large (for example, when the amount of electricity for charging per mass of the positive electrode active material is 400 mAh / g or more). ) Also, a method for efficiently selecting a substitution element suitable for the oxide contained in the positive electrode active material having high Coulomb efficiency, a positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large, such a positive electrode activity. It is an object of the present invention to provide a positive electrode having a substance, a non-aqueous electrolyte power storage element and a power storage device, a method for manufacturing the positive electrode active material, a method for manufacturing the positive electrode, and a method for manufacturing the non-aqueous electrolyte power storage element.
　本発明の一態様は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質における上記第一置換元素及び上記第二置換元素を選択する方法であって、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素として、第一原理計算に基づく計算結果が下記条件Ａ及び条件Ｂを満たす組み合わせを選択することを備える置換元素の選択方法である。
　条件Ａ：上記酸化物の所定の充電状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が所定値以上であること
　条件Ｂ：上記酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が所定値以下であること One aspect of the present invention is the first substitution element and the second substitution in a positive electrode active material containing lithium, a first substitution element and a second substitution element, and containing an oxide having an inverted fluorite-type crystal structure. In the method of selecting an element, the first substitution element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups, and the second substitution element is the second to the second group. It is an element other than nitrogen, oxygen, sulfur and selenium that belongs to any of Group 5 and Groups 12 to 16, and is the calculation result based on the first principle calculation as the first substitution element and the second substitution element. Is a method for selecting a substitution element, which comprises selecting a combination satisfying the following conditions A and B.
Condition A: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
　本発明の他の一態様は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質（Ａ）である。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること Another aspect of the present invention contains an oxide containing lithium, a first substituted element and a second substituted element and having an inverted fluorite-type crystal structure, and the first substituted element is from Group 6 An element other than technetium and tungsten belonging to any of the 11th group, and the second substitution element belongs to any of the 2nd to 5th groups and the 12th to 16th groups, nitrogen, oxygen, and the like. It is an element other than sulfur and selenium, and is a positive electrode active material (A) in which the first substitution element and the second substitution element are a combination in which the calculation result based on the first principle calculation satisfies the following conditions a and b. ..
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　本発明の他の一態様は、本発明の一態様に係る置換元素の選択方法を用いて選択された第一置換元素及び第二置換元素並びにリチウムを含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記条件Ａ及び条件Ｂにおける所定の充電状態が４００ｍＡｈ／ｇまで充電した状態であり、上記条件Ａにおける上記存在比の所定値が０．５３であり、上記条件Ｂにおける上記存在比の所定値が０．１１である正極活物質（Ｂ）である。 Another aspect of the present invention comprises the first and second substituents and lithium selected using the method for selecting a substituent according to one aspect of the present invention, and has an inverted fluorite-type crystal structure. It contains an oxide having an oxide, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0.53. The positive electrode active material (B) has a predetermined value of the abundance ratio of 0.11.
　本発明の他の一態様は、本発明の一態様に係る正極活物質（Ａ）又は正極活物質（Ｂ）を含有する非水電解質蓄電素子用の正極である。 Another aspect of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing a positive electrode active material (A) or a positive electrode active material (B) according to one aspect of the present invention.
　本発明の他の一態様は、本発明の一態様に係る正極を備える非水電解質蓄電素子である。 Another aspect of the present invention is a non-aqueous electrolyte power storage element provided with a positive electrode according to one aspect of the present invention.
　本発明の他の一態様は、非水電解質蓄電素子を複数個備え、且つ本発明の一態様に係る非水電解質蓄電素子を一以上備える蓄電装置である。 Another aspect of the present invention is a power storage device including a plurality of non-aqueous electrolyte power storage elements and one or more non-water electrolyte power storage elements according to one aspect of the present invention.
　本発明の他の一態様は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質を製造する方法であって、本発明の一態様に係る置換元素の選択方法を用いて選択された上記第一置換元素及び上記第二置換元素を含む材料を処理することを備える正極活物質の製造方法（Ａ）である。 Another aspect of the present invention is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. It is a method (A) for producing a positive electrode active material comprising treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to one aspect of the present invention.
　本発明の他の一態様は、本発明の一態様に係る置換元素の選択方法により、上記第一置換元素及び上記第二置換元素の組み合わせを選択すること、及びリチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理することを備える正極活物質の製造方法（Ｂ）である。 In another aspect of the present invention, the combination of the first substitution element and the second substitution element is selected by the method for selecting a substitution element according to one aspect of the present invention, and lithium, oxygen, and the first substitution are used. It is a method (B) for producing a positive electrode active material, which comprises treating a material containing an element and the second substituted element by a mechanochemical method.
　本発明の他の一態様は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質の製造方法であって、リチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理することを備え、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質の製造方法（Ｃ）である。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること Another aspect of the present invention is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. The technetium and tungsten are provided by treating a material containing oxygen, the first substitution element and the second substitution element by a mechanochemical method, and the first substitution element belongs to any of Group 6 to Group 11. The second substitution element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is the first element. It is a method (C) for producing a positive electrode active material in which the substitution element and the second substitution element are a combination in which the calculation result based on the first-principles calculation satisfies the following conditions a and b.
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　本発明の他の一態様は、本発明の一態様に係る正極活物質（Ａ）若しくは正極活物質（Ｂ）又は本発明の一態様に係る正極活物質の製造方法（Ａ）から（Ｃ）のいずれかで得られた正極活物質を用いて正極を作製することを備える非水電解質蓄電素子用の正極の製造方法である。 Another aspect of the present invention is the positive electrode active material (A) or the positive electrode active material (B) according to the one aspect of the present invention, or the methods (A) to (C) for producing the positive electrode active material according to the one aspect of the present invention. It is a method of manufacturing a positive electrode for a non-aqueous electrolyte power storage element, which comprises producing a positive electrode using the positive electrode active material obtained in any of the above.
　本発明の他の一態様は、本発明の一態様に係る正極の製造方法を備える非水電解質蓄電素子の製造方法である。 Another aspect of the present invention is a method for manufacturing a non-aqueous electrolyte power storage element, which comprises a method for manufacturing a positive electrode according to one aspect of the present invention.
　本発明のいずれかの態様によれば、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質に含有される酸化物に好適な置換元素を効率的に選択する方法、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質、このような正極活物質を有する正極、非水電解質蓄電素子、及び蓄電装置、上記正極活物質の製造方法、上記正極の製造方法、並びに上記非水電解質蓄電素子の製造方法を提供することができる。 According to any aspect of the present invention, a method for efficiently selecting a substitution element suitable for an oxide contained in a positive electrode active material having a high Coulomb efficiency even when the amount of charging electricity is relatively large, the amount of charging electricity is A positive electrode active material having a high Coulomb efficiency even when it is relatively large, a positive electrode having such a positive electrode active material, a non-aqueous electrolyte power storage element, and a power storage device, a method for manufacturing the positive electrode active material, a method for manufacturing the positive electrode, and the above non. It is possible to provide a method for manufacturing a water electrolyte storage element.
図１は、本発明の一実施形態に係る非水電解質蓄電素子を示す外観斜視図である。FIG. 1 is an external perspective view showing a non-aqueous electrolyte power storage element according to an embodiment of the present invention. 図２は、本発明の一実施形態に係る非水電解質蓄電素子を複数個集合して構成した蓄電装置を示す概略図である。FIG. 2 is a schematic view showing a power storage device configured by assembling a plurality of non-aqueous electrolyte power storage elements according to an embodiment of the present invention. 図３は、実施例２、３及び比較例１、２で得られた各正極活物質のＣｕＫα線を用いたエックス線回折図である。FIG. 3 is an X-ray diffraction diagram using CuKα rays of each positive electrode active material obtained in Examples 2 and 3 and Comparative Examples 1 and 2. 図４は、実施例４、５で得られた各正極活物質のＣｕＫα線を用いたエックス線回折図である。FIG. 4 is an X-ray diffraction diagram using CuKα rays of each positive electrode active material obtained in Examples 4 and 5. 図５は、実施例１７の評価セル（正極活物質Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ）の充電時の正極電位及びセルの膨れ量の変化を表すグラフである。FIG. 5 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell of Example 17 (positive electrode active material Li 1.444 Co 0.194 B 0.056 O). 図６は、比較例７の評価セル（正極活物質Ｌｉ１．３８９Ｃｏ０．１３９Ａｌ０．１１１Ｏ）の充電時の正極電位及びセルの膨れ量の変化を表すグラフである。FIG. 6 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell (positive electrode active material Li 1.389 Co 0.139 Al 0.111 O) of Comparative Example 7.
　初めに、本明細書によって開示される置換元素の選択方法、正極活物質、正極、非水電解質蓄電素子、蓄電装置、正極活物質の製造方法、正極の製造方法、及び非水電解質蓄電素子の製造方法の概要について説明する。 First, of the method for selecting a substitution element disclosed herein, a positive electrode active material, a positive electrode, a non-aqueous electrolyte storage element, a power storage device, a method for producing a positive electrode active material, a method for producing a positive electrode, and a non-aqueous electrolyte storage element. The outline of the manufacturing method will be described.
　本発明の一態様に係る置換元素の選択方法は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質における上記第一置換元素及び上記第二置換元素を選択する方法であって、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素として、第一原理計算に基づく計算結果が下記条件Ａ及び条件Ｂを満たす組み合わせを選択することを備える置換元素の選択方法である。
　条件Ａ：上記酸化物の所定の充電状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が所定値以上であること
　条件Ｂ：上記酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が所定値以下であること The method for selecting a substitution element according to one aspect of the present invention is the above-mentioned first method for a positive electrode active material containing lithium, a first substitution element and a second substitution element, and an oxide having an inverted fluorite-type crystal structure. A method for selecting a substitution element and the second substitution element, wherein the first substitution element is an element other than technetium and tungsten belonging to any of Group 6 to Group 11, and the second substitution element. Is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is the first and second substituted element. This is a method for selecting a substitution element, which comprises selecting a combination in which the calculation result based on the one-principles calculation satisfies the following conditions A and B.
Condition A: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
　本発明の一態様に係る置換元素の選択方法によれば、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質に含有される酸化物に好適な置換元素を効率的に選択することができる。この理由は以下の通りである。Ｌｉ２ＯにＣｏ等の第一置換元素を固溶させた従来の正極活物質は、充電状態で第一置換元素間の近接化（マイグレーション）が生じ易い。第一置換元素のマイグレーションが生じると、酸素の配位数が４配位である第一置換元素の存在比が減り、酸素の配位数が６配位である第一置換元素の存在比が増えることにより、酸素レドックス反応を発現させるための触媒活性能が低下する。この構造変化は可逆性が低いため、充放電の繰り返しに伴い、クーロン効率は低下していく。また、Ｌｉ２Ｏに第一置換元素としてＣｏ等と共に第二置換元素としてのＡｌをさらに固溶させた正極活物質の場合、Ａｌによって第一置換元素間のマイグレーションは抑制されると考えられる。しかし、Ａｌをさらに固溶させた結果、充電時に酸素ガスの放出が生じ易くなるため、クーロン効率は十分には改善されない。このような従来の正極活物質に対し、本発明の一態様に係る置換元素の選択方法においては、第一原理計算に基づく計算結果において条件Ａとして充電状態で酸素の配位数が４配位である第一置換元素の存在比が高いこと、及び条件Ｂとして充電状態で電荷が－０．５より大きい酸素の存在比が低いことを満たす第一置換元素及び第二置換元素の組み合わせを選択することとしている。条件Ａの酸素の配位数が４配位である第一置換元素の存在比が高いことにより、酸素レドックス活性化能の低下が抑えられる。また、条件Ｂの電荷が－０．５より大きい酸素は超酸化物イオン又は酸素分子の電子状態に対応する、結晶構造中で不安定な酸素である。このため、電荷が－０．５より大きい酸素の存在比が低いことにより、結晶構造中に安定して存在する酸素の比率が高まり、酸素ガスの放出が抑制される。従って、当該選択方法において、第一置換元素及び第二置換元素として第一原理計算に基づく計算結果が条件Ａ及び条件Ｂを満たす組み合わせを選択することで、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質に含有される酸化物に好適な置換元素を効率的に選択することができる。 According to the method for selecting a substitution element according to one aspect of the present invention, a substitution element suitable for an oxide contained in a positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large is efficiently selected. Can be done. The reason for this is as follows. In the conventional positive electrode active material in which a primary substituent such as Co is dissolved in Li 2 O, proximity (migration) between the primary substituents is likely to occur in a charged state. When the migration of the first substituted element occurs, the abundance ratio of the first substituted element having an oxygen coordination number of 4 decreases, and the abundance ratio of the first substituted element having an oxygen coordination number of 6 coordinates decreases. By increasing the amount, the catalytic activity for expressing the oxygen redox reaction decreases. Since this structural change has low reversibility, the Coulomb efficiency decreases with repeated charging and discharging. Further, in the case of a positive electrode active material in which Al as a second substitution element is further dissolved in Li 2O together with Co or the like as a first substitution element, it is considered that migration between the first substitution elements is suppressed by Al. However, as a result of further solid-solving Al, oxygen gas is likely to be released during charging, so that the Coulomb efficiency is not sufficiently improved. In the method of selecting a substitution element according to one aspect of the present invention with respect to such a conventional positive electrode active material, the oxygen coordination number is 4 coordinations in a charged state as condition A in the calculation result based on the first-principles calculation. Select a combination of the first substitution element and the second substitution element that satisfy the high abundance ratio of the first substitution element and the low abundance ratio of oxygen having a charge greater than -0.5 in the charged state as the condition B. I'm supposed to do it. Since the abundance ratio of the first substituent having a coordination number of 4 oxygen under the condition A is high, the decrease in the oxygen redox activation ability is suppressed. Further, oxygen having a charge greater than −0.5 under the condition B is an oxygen unstable in the crystal structure corresponding to the electronic state of the superoxide ion or the oxygen molecule. Therefore, since the abundance ratio of oxygen having a charge greater than −0.5 is low, the ratio of oxygen stably present in the crystal structure is increased, and the release of oxygen gas is suppressed. Therefore, in the selection method, by selecting a combination of the first substitution element and the second substitution element whose calculation results based on the first-principles calculation satisfy the conditions A and B, the Coulomb can be charged even when the amount of charging electricity is relatively large. It is possible to efficiently select a substitution element suitable for the oxide contained in the highly efficient positive electrode active material.
　本発明の一態様に係る正極活物質は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質（Ａ）である。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること The positive electrode active material according to one aspect of the present invention contains lithium, a first substituted element and a second substituted element, and contains an oxide having an inverted fluorite-type crystal structure, and the first substituted element is the first. An element other than technetium and tungsten, which belongs to any of Group 6 to Group 11, and the second substituent belongs to any of Group 2 to Group 5 and Group 12 to Group 16, nitrogen. , An element other than oxygen, sulfur and selenium, and the positive electrode active material (A) in which the first substitution element and the second substitution element are a combination in which the calculation result based on the first principle calculation satisfies the following conditions a and b. ).
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　当該正極活物質（Ａ）は、充電電気量が比較的大きい場合もクーロン効率が高い。また、当該正極活物質（Ａ）は、充放電を繰り返してもこの高いクーロン効率が維持されやすい。この理由は、第一原理計算に基づく計算結果において、所定充電状態における酸素の配位数が４配位である第一置換元素の存在比が高いという条件ａを満たすことにより、酸素レドックス活性化能の低下が抑えられ、所定充電状態における電荷が－０．５より大きい酸素の存在比が低いという条件ｂを満たすことにより、酸素ガスの放出が抑制されることによると推測される。このような結果、本発明の一態様に係る正極活物質（Ａ）においては、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすくなっていると推測される。 The positive electrode active material (A) has high Coulomb efficiency even when the amount of charging electricity is relatively large. Further, the positive electrode active material (A) tends to maintain this high Coulomb efficiency even after repeated charging and discharging. The reason for this is that oxygen redox activation is achieved by satisfying the condition a that the abundance ratio of the first substituted element having four coordination numbers of oxygen in a predetermined charging state is high in the calculation result based on the first-principles calculation. It is presumed that the release of oxygen gas is suppressed by satisfying the condition b that the decrease in function is suppressed and the abundance ratio of oxygen whose charge is larger than −0.5 in a predetermined charge state is low. As a result, in the positive electrode active material (A) according to one aspect of the present invention, the coulombic efficiency is high even when the amount of charging electricity is relatively large, and it becomes easy to maintain this high coulombic efficiency even after repeated charging and discharging. It is presumed that it is.
　当該正極活物質（Ａ）においては、上記第二置換元素が、シャノンの有効イオン半径が０．６０Å未満である元素であることが好ましい。幾何学構造的に、アニオンが酸化物イオンのとき、カチオンのイオン半径が０．６０Å未満であれば４配位構造が形成されやすい。従って、当該正極活物質（Ａ）において、第二置換元素の有効イオン半径が０．６０Å未満の場合、４配位構造が形成されやすく、逆蛍石型の結晶構造の安定性が高まる。従って、第二置換元素がこのような元素である場合、充電電気量が比較的大きい場合もクーロン効率がより高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極活物質となる。 In the positive electrode active material (A), it is preferable that the second substitution element is an element having an effective ionic radius of Shannon of less than 0.60 Å. Geometrically, when the anion is an oxide ion, a four-coordination structure is likely to be formed if the ionic radius of the cation is less than 0.60 Å. Therefore, in the positive electrode active material (A), when the effective ionic radius of the second substituent is less than 0.60 Å, a four-coordination structure is likely to be formed, and the stability of the inverted fluorite-type crystal structure is enhanced. Therefore, when the second substitution element is such an element, the coulomb efficiency is higher even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulomb efficiency even after repeated charging and discharging.
　なお、上記シャノンの有効イオン半径は、以下の文献の記載に基づく。
　Ｒ．Ｄ．Ｓｈａｎｎｏｎ，“Ｒｅｖｉｓｅｄ　Ｅｆｆｅｃｔｉｖｅ　Ｉｏｎｉｃ　Ｒａｄｉｉ　ａｎｄ　Ｓｙｓｔｅｍａｔｉｃ　Ｓｔｕｄｉｅｓ　ｏｆ　Ｉｎｔｅｒａｔｏｍｉｅ　Ｄｉｓｔａｎｃｅｓ　ｉｎ　Ｈａｌｉｄｅｓ　ａｎｄ　Ｃｈａｌｅｏｇｅｎｉｄｅｓ”Ａｃｔａ　Ｃｒｙｓｔａｌｌｏｇｒａｐｈｉｃａ，１９７６，Ａ３２，ｐ７５１－７６７
　また、上記第二置換元素の有効イオン半径は、当該正極活物質（Ａ）に含有される酸化物中でのカチオンの状態（価数）でのイオン半径とする。すなわち、第二置換元素が例えば３価のカチオンの状態で酸化物中に存在している場合、この３価のカチオンの有効イオン半径とする。また、上記第二置換元素の有効イオン半径は、配位数が４配位であるときの値とし、複数のスピン状態をとる元素の場合は、高スピン状態であるときの値とする。 The effective ionic radius of Shannon is based on the description in the following documents.
R. D. Shannon, "Revised Effective Ionic Radii and Systems of Interatomie Distances in Halides and Halides and Chaleogenides" Acta 1976A
The effective ionic radius of the second substitution element is the ionic radius in the state (valence) of the cation in the oxide contained in the positive electrode active material (A). That is, when the second substitution element is present in the oxide in the state of a trivalent cation, for example, it is set as the effective ionic radius of this trivalent cation. Further, the effective ionic radius of the second substitution element is a value when the coordination number is four coordinations, and in the case of an element having a plurality of spin states, it is a value when the coordination number is a high spin state.
　当該正極活物質（Ａ）においては、上記第一置換元素が、コバルト、鉄、銅、マンガン、ニッケル、クロム又はこれらの組み合わせであり、上記第二置換元素が、ホウ素、炭素、マグネシウム、ケイ素、リン、チタン、ガリウム、スズ又はこれらの組み合わせであることが好ましい。第一置換元素及び第二置換元素がこれらの元素又はこれらの組み合わせである場合、充電電気量が比較的大きい場合もクーロン効率がより高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極活物質を確実性高く提供することができる。 In the positive electrode active material (A), the first substituent is cobalt, iron, copper, manganese, nickel, chromium or a combination thereof, and the second substituent is boron, carbon, magnesium, silicon, or a combination thereof. It is preferably phosphorus, titanium, gallium, tin or a combination thereof. When the first substitution element and the second substitution element are these elements or a combination thereof, the coulomb efficiency is higher even when the charge electricity amount is relatively large, and this high coulomb efficiency is likely to be maintained even after repeated charging and discharging. The positive electrode active material can be provided with high certainty.
　本発明の他の一態様に係る正極活物質は、本発明の一態様に係る置換元素の選択方法を用いて選択された第一置換元素及び第二置換元素並びにリチウムを含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記条件Ａ及び条件Ｂにおける所定の充電状態が４００ｍＡｈ／ｇまで充電した状態であり、上記条件Ａにおける上記存在比の所定値が０．５３であり、上記条件Ｂにおける上記存在比の所定値が０．１１である正極活物質（Ｂ）である。 The positive electrode active material according to another aspect of the present invention contains the first and second substitution elements and lithium selected by using the method for selecting a substitution element according to one aspect of the present invention, and is a reverse fluorite. It contains an oxide having a type crystal structure, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0.53. , The positive electrode active material (B) in which the predetermined value of the abundance ratio under the above condition B is 0.11.
　当該正極活物質（Ｂ）も、上述した正極活物質（Ａ）と同様に推測される理由から、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。 The positive electrode active material (B) also has high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency even when charging and discharging are repeated, for the reason that it is presumed to be the same as the positive electrode active material (A) described above. Is easy to maintain.
　本発明の一態様に係る正極活物質（Ａ）及び正極活物質（Ｂ）においては、上記酸化物のＣｕＫα線を用いたエックス線回折図において、回折角２θが３３°付近の回折ピークの半値幅が０．３°以上であることが好ましい。 In the positive electrode active material (A) and the positive electrode active material (B) according to one aspect of the present invention, in the X-ray diffraction diagram using the CuKα ray of the oxide, the half width of the diffraction peak in which the diffraction angle 2θ is around 33 °. Is preferably 0.3 ° or more.
　このような構成によれば、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質を確実性高く提供することができる。回折角２θが３３°付近の回折ピークとは、回折角２θが３０°から３５°の範囲内で最も回折強度が強いピークを指す。 According to such a configuration, it is possible to provide a positive electrode active material having high Coulomb efficiency with high certainty even when the amount of charging electricity is relatively large. The diffraction peak in which the diffraction angle 2θ is around 33 ° refers to the peak having the strongest diffraction intensity in the range of the diffraction angle 2θ of 30 ° to 35 °.
　上記酸化物のエックス線回折測定は、エックス回折装置（Ｒｉｇａｋｕ社の「ＭｉｎｉＦｌｅｘ　ＩＩ」）を用いた粉末エックス線回折測定によって、線源をＣｕＫα線、管電圧を３０ｋＶ、管電流を１５ｍＡとして行う。このとき、回折エックス線は、厚さ３０μｍのＫβフィルターを通り、高速一次元検出器（Ｄ／ｔｅＸ　Ｕｌｔｒａ　２）にて検出される。また、サンプリング幅は０．０２°、スキャンスピードは５°／ｍｉｎ、発散スリット幅は０．６２５°、受光スリット幅は１３ｍｍ（ＯＰＥＮ）、散乱スリット幅は８ｍｍとする。上記エックス線回折測定により得られたエックス線回折図を、ＰＤＸＬ（解析ソフト、Ｒｉｇａｋｕ製）を用いて自動解析処理する。ここで、ＰＤＸＬソフトの作業ウィンドウで「バックグラウンドを精密化する」及び「自動」を選択し、実測パターンと計算パターンの強度誤差が１０００以下になるように精密化する。この精密化によってバックグラウンド処理がされ、ベースラインを差し引いた値として、各回折線のピーク強度の値、及び半値幅の値、等が得られる。 The X-ray diffraction measurement of the oxide is carried out by powder X-ray diffraction measurement using an X-diffraction device (“MiniFlex II” manufactured by Rigaku Co., Ltd.) with a CuKα ray as the radiation source, a tube voltage of 30 kV, and a tube current of 15 mA. At this time, the diffracted X-rays pass through a Kβ filter having a thickness of 30 μm and are detected by a high-speed one-dimensional detector (D / teX Ultra 2). The sampling width is 0.02 °, the scan speed is 5 ° / min, the divergent slit width is 0.625 °, the light receiving slit width is 13 mm (OPEN), and the scattering slit width is 8 mm. The X-ray diffraction pattern obtained by the above-mentioned X-ray diffraction measurement is automatically analyzed using PDXL (analysis software, manufactured by Rigaku). Here, "precision background" and "automatic" are selected in the work window of the PDXL software, and the strength error between the measured pattern and the calculated pattern is refined to 1000 or less. Background processing is performed by this refinement, and the value of the peak intensity of each diffraction line, the value of the half width, and the like are obtained as the values obtained by subtracting the baseline.
　本発明の一態様に係る正極は、本発明の一態様に係る正極活物質（Ａ）又は正極活物質（Ｂ）を含有する非水電解質蓄電素子用の正極である。当該正極は本発明の一態様に係る正極活物質（Ａ）又は正極活物質（Ｂ）を含有するため、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。 The positive electrode according to one aspect of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing the positive electrode active material (A) or the positive electrode active material (B) according to one aspect of the present invention. Since the positive electrode contains the positive electrode active material (A) or the positive electrode active material (B) according to one aspect of the present invention, the coulombic efficiency is high even when the amount of charging electricity is relatively large, and this is high even when charging and discharging are repeated. Coulomb efficiency is easy to maintain.
　本発明の一態様に係る非水電解質蓄電素子は、本発明の一態様に係る正極を備える非水電解質蓄電素子（以下、単に「蓄電素子」ということもある。）である。当該蓄電素子は、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。 The non-aqueous electrolyte power storage element according to one aspect of the present invention is a non-aqueous electrolyte power storage element having a positive electrode according to one aspect of the present invention (hereinafter, may be simply referred to as “storage element”). The power storage element has a high coulombic efficiency even when the amount of charging electricity is relatively large, and the high coulombic efficiency is likely to be maintained even after repeated charging and discharging.
　本発明の一態様に係る蓄電装置は、非水電解質蓄電素子を複数個備え、且つ本発明の一態様に係る非水電解質蓄電素子を一以上備える蓄電装置である。当該蓄電装置は、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。 The power storage device according to one aspect of the present invention is a power storage device including a plurality of non-aqueous electrolyte power storage elements and one or more non-water electrolyte power storage elements according to one aspect of the present invention. The power storage device has a high coulombic efficiency even when the amount of charging electricity is relatively large, and it is easy to maintain this high coulombic efficiency even after repeated charging and discharging.
　本発明の一態様に係る正極活物質の製造方法は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質を製造する方法であって、本発明の一態様に係る置換元素の選択方法を用いて選択された上記第一置換元素及び上記第二置換元素を含む材料を処理することを備える正極活物質の製造方法（Ａ）である。 The method for producing a positive electrode active material according to one aspect of the present invention produces a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. A method for producing a positive electrode active material, which comprises treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to one aspect of the present invention. A).
　当該正極活物質の製造方法（Ａ）によれば、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極活物質を製造することができる。 According to the method for producing a positive electrode active material (A), it is possible to produce a positive electrode active material which has a high coulombic efficiency even when the amount of charging electricity is relatively large and can easily maintain this high coulombic efficiency even after repeated charging and discharging. can.
　本発明の他の一態様に係る正極活物質の製造方法は、本発明の一態様に係る置換元素の選択方法により、上記第一置換元素及び上記第二置換元素の組み合わせを選択すること、及びリチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理することを備える正極活物質の製造方法（Ｂ）である。 In the method for producing a positive electrode active material according to another aspect of the present invention, a combination of the first substitution element and the second substitution element is selected by the method for selecting a substitution element according to one aspect of the present invention, and the combination of the first substitution element and the second substitution element is selected. It is a method (B) for producing a positive electrode active material comprising treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method.
　当該正極活物質の製造方法（Ｂ）によっても、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極活物質を製造することができる。 Depending on the method (B) for producing the positive electrode active material, the coulombic efficiency is high even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulombic efficiency even after repeated charging and discharging. ..
　本発明の他の一態様に係る正極活物質の製造方法は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質の製造方法であって、リチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理することを備え、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質の製造方法（Ｃ）である。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること The method for producing a positive electrode active material according to another aspect of the present invention is a method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. The production method comprises treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method, and the first substitution element is a group 6 to 11 of the above. Elements other than technetium and tungsten that belong to any of the above, and the second substitution element belongs to any of Group 2 to Group 5 and Groups 12 to 16 and other than nitrogen, oxygen, sulfur and selenium. The method (C) for producing a positive electrode active material, wherein the first substitution element and the second substitution element are a combination of the above-mentioned first substitution element and the above-mentioned second substitution element, and the calculation result based on the first-principles calculation satisfies the following conditions a and b.
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　当該正極活物質の製造方法（Ｃ）によっても、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極活物質を製造することができる。 Depending on the method (C) for producing the positive electrode active material, the coulombic efficiency is high even when the amount of charging electricity is relatively large, and the positive electrode active material can easily maintain this high coulombic efficiency even after repeated charging and discharging. ..
　本発明の一態様に係る正極の製造方法は、本発明の一態様に係る正極活物質（Ａ）若しくは正極活物質（Ｂ）又は本発明の一態様に係る正極活物質の製造方法（Ａ）から（Ｃ）のいずれかで得られた正極活物質を用いて正極を作製することを備える非水電解質蓄電素子用の正極の製造方法である。 The method for producing a positive electrode according to one aspect of the present invention is the positive electrode active material (A) or positive electrode active material (B) according to one aspect of the present invention, or the method for producing a positive electrode active material according to one aspect of the present invention (A). A method for manufacturing a positive electrode for a non-aqueous electrolyte power storage element, which comprises producing a positive electrode using the positive electrode active material obtained in any of (C).
　当該正極の製造方法によれば、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい正極を製造することができる。 According to the method for manufacturing the positive electrode, the coulomb efficiency is high even when the amount of charging electricity is relatively large, and it is possible to manufacture a positive electrode in which this high coulomb efficiency can be easily maintained even after repeated charging and discharging.
　本発明の一態様に係る非水電解質蓄電素子の製造方法は、本発明の一態様に係る正極の製造方法を備える非水電解質蓄電素子の製造方法である。 The method for manufacturing a non-aqueous electrolyte power storage element according to one aspect of the present invention is a method for manufacturing a non-aqueous electrolyte power storage element including the method for manufacturing a positive electrode according to one aspect of the present invention.
　当該非水電解質蓄電素子の製造方法によれば、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい非水電解質蓄電素子を製造することができる。 According to the method for manufacturing the non-aqueous electrolyte power storage element, the coulomb efficiency is high even when the amount of charging electricity is relatively large, and the non-water electrolyte power storage element which can easily maintain this high coulomb efficiency even after repeated charging and discharging is manufactured. Can be done.
　以下、本発明の一実施形態に係る置換元素の選択方法、正極活物質、正極活物質の製造方法、正極、正極の製造方法、非水電解質蓄電素子、及び非水電解質蓄電素子の製造方法について、順に説明する。 Hereinafter, a method for selecting a substitution element, a method for producing a positive electrode active material, a method for producing a positive electrode active material, a method for producing a positive electrode and a positive electrode, a method for producing a non-aqueous electrolyte power storage element, and a method for producing a non-aqueous electrolyte power storage element according to an embodiment of the present invention will be provided. , Will be explained in order.
＜置換元素の選択方法＞
　本発明の一実施形態に係る置換元素の選択方法は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質における上記第一置換元素及び上記第二置換元素を選択する方法であって、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素として、第一原理計算に基づく計算結果が下記条件Ａ及び条件Ｂを満たす組み合わせを選択することを備える置換元素の選択方法である。
　条件Ａ：上記酸化物の所定の充電状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が所定値以上であること
　条件Ｂ：上記酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が所定値以下であること <Selection method of substitution element>
The method for selecting a substitution element according to an embodiment of the present invention is the above-mentioned first in a positive electrode active material containing lithium, a first substitution element and a second substitution element, and containing an oxide having an inverted fluorite-type crystal structure. A method for selecting a mono-substituted element and the second-substituted element, wherein the first-substituted element is an element other than technetium and tungsten, which belongs to any of Group 6 to Group 11, and the second-substituted element. The element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is used as the first substitution element and the second substitution element. It is a method of selecting a substitution element comprising selecting a combination in which the calculation result based on the first-principles calculation satisfies the following conditions A and B.
Condition A: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
　第一原理計算とは、非経験的に物性の予測を行う計算方法であり、原子番号と空間座標が既知の原子を含むモデルの全エネルギーと、電子のエネルギーバンド構造を計算することができる手法である。原子に働く力を計算することで構造最適化が可能になり、また、格子定数、０Ｋ時の安定構造及びバンドギャップ等が計算できる。計算方法には、大きく分けると、「波動関数理論」系と「密度汎関数理論」系の二種類が存在する。本明細書において用いた計算方法は、密度汎関数理論に基づくものである。 First-principles calculation is an ab initio prediction method that can calculate the total energy of a model including atoms with known atomic numbers and spatial coordinates, and the energy band structure of electrons. Is. Structure optimization is possible by calculating the force acting on the atom, and the lattice constant, stable structure at 0K, band gap, etc. can be calculated. There are roughly two types of calculation methods, the "wave function theory" system and the "density functional theory" system. The calculation method used in the present specification is based on the density functional theory.
　本発明の一実施形態に係る置換元素の選択方法は、例えば、具体的には以下の（１）から（３）の手順で行うことができる。 The method for selecting a substitution element according to an embodiment of the present invention can be specifically carried out by the following procedures (1) to (3).
（１）候補酸化物の選択
　当該置換元素の選択方法においては、先ず候補となる酸化物を選択する。この酸化物（候補酸化物）は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有するものである。候補酸化物に含まれる第一置換元素は、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、例えばコバルト、鉄、銅、マンガン、ニッケル、クロム等が挙げられる。候補酸化物に含まれる第二置換元素は、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、例えばホウ素、炭素、マグネシウム、ケイ素、リン、チタン、ガリウム、スズ等が挙げられる。 (1) Selection of Candidate Oxide In the method of selecting the substitution element, the candidate oxide is first selected. This oxide (candidate oxide) contains lithium, a first-substituted element and a second-substituted element, and has an inverted fluorite-type crystal structure. The first substituent contained in the candidate oxide is an element other than technetium and tungsten belonging to any of Group 6 to Group 11, and examples thereof include cobalt, iron, copper, manganese, nickel, and chromium. .. The second substitution element contained in the candidate oxide is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, and is, for example, boron and carbon. , Magnesium, silicon, phosphorus, titanium, gallium, tin and the like.
　候補酸化物を構成する元素の組成比は逆蛍石型の結晶構造をとることができる限り特に限定されるものではないが、例えば下記式（１）で表される組成式を有するものであってよい。
　［Ｌｉ２－２ｚＭ２ｘＡ２ｙ］Ｏ　・・・（１）
　上記式（１）中、Ｍは、第一置換元素である。Ａは、第二置換元素である。ｘ、ｙ及びｚは、下記式（ａ）から（ｃ）を満たす。
　０＜ｘ＜１　・・・（ａ）
　０＜ｙ＜１　・・・（ｂ）
　ｘ＋ｙ≦ｚ＜１　・・・（ｃ） The composition ratio of the elements constituting the candidate oxide is not particularly limited as long as it can have an inverted fluorite-type crystal structure, but for example, it has a composition formula represented by the following formula (1). It's okay.
[Li 2-2z M 2x A 2y ] O ... (1)
In the above formula (1), M is a first substitution element. A is a second substitution element. x, y and z satisfy the following formulas (a) to (c).
0 <x <1 ... (a)
0 <y <1 ... (b)
x + y ≦ z <1 ... (c)
　また、候補酸化物の組成式は下記式（２）で表されるものであってもよい。
　ＬｉｍＭｎＡ９－ｎＯ３６　・・・（２）
　上記式（２）中、Ｍは、第一置換元素である。Ａは、第二置換元素である。ｍは、化学量論比に基づく整数である。ｎは、１以上８以下の整数である。ｎは、例えば５又は７とすることができる。 Further, the composition formula of the candidate oxide may be represented by the following formula (2).
Li m M n A 9-n O 36 ... (2)
In the above formula (2), M is a first substitution element. A is a second substitution element. m is an integer based on the stoichiometric ratio. n is an integer of 1 or more and 8 or less. n can be, for example, 5 or 7.
（２）原子配列の決定
　上記「（１）候補酸化物の選択」にて選択した候補酸化物に対して、まず、現実に存在し得る安定な原子配列（リチウム、第一置換元素、第二置換元素及び空孔の空間的な配置）を求めるために、遺伝的アルゴリズムを組み合わせた第一原理計算を行う。原子配列には膨大な組み合わせが考えられ、全通りの評価が不可能であるため、遺伝的アルゴリズムを活用する。結晶モデルについては、Ｌｉ２Ｏ（空間群：Ｆｍ－３ｍ）の単位結晶格子（ｕｎｉｔ　ｃｅｌｌ）をｘ軸、ｙ軸、ｚ軸方向へそれぞれ３倍、３倍、４倍に伸ばした３×３×４スーパーセル（ｓｕｐｅｒｃｅｌｌ）を生成した後、リチウムの占有サイトを対象として原子配列を最適化する。 (2) Determination of atomic arrangement For the candidate oxide selected in "(1) Selection of candidate oxide" above, first, a stable atomic arrangement (lithium, first substituent, second) that can actually exist. In order to obtain the spatial arrangement of substitution elements and vacancies), a first-principles calculation combined with a genetic algorithm is performed. Since a huge number of combinations are possible for the atomic arrangement and it is impossible to evaluate all of them, a genetic algorithm is used. For the crystal model, the unit crystal lattice (unit cell) of Li 2 O (space group: Fm-3m) is stretched 3 times, 3 times, and 4 times in the x-axis, y-axis, and z-axis directions, respectively, 3 × 3. After generating the × 4 supercell, the atomic arrangement is optimized for the lithium-occupied site.
　遺伝的アルゴリズムとは生物進化の過程を模倣した最適化アルゴリズムの一種であり、パラメーターを遺伝子で表した複数の個体から、優秀な遺伝子を優先的に組み替える作業を繰り返すことで、最適な個体を短期間で探索することのできる手法である。遺伝的アルゴリズムの計算条件の一例を以下に示す。
　１個体あたりの遺伝子の数：１
　１世代ごとに生成する個体数：２０
　１世代ごとに生存させる個体の割合：０．６
　２点交叉の割合：０．４
　一様交叉の割合：０．４
　遺伝子操作せずに無条件で次世代に引き継ぐ上位個体の数：３
　一様交叉の発生確率：０．８
　突然変異の発生確率：０．０２
　最大世代数：２００
　収束判定：最安定個体が１０世代連続で更新されなかったとき A genetic algorithm is a kind of optimization algorithm that imitates the process of biological evolution, and by repeating the work of preferentially rearranging excellent genes from multiple individuals whose parameters are represented by genes, the optimum individual can be selected in a short period of time. It is a method that can be searched between. An example of the calculation conditions of the genetic algorithm is shown below.
Number of genes per individual: 1
Number of individuals generated per generation: 20
Percentage of individuals to survive per generation: 0.6
Ratio of two-point crossover: 0.4
Uniform crossover ratio: 0.4
Number of top individuals to pass on to the next generation unconditionally without genetic manipulation: 3
Probability of uniform crossover: 0.8
Mutation probability: 0.02
Maximum number of generations: 200
Convergence test: When the most stable individual is not updated for 10 consecutive generations
　「（２）原子配列の決定」における第一原理計算にあたっては、例えば、計算ソフトウェアＶｉｅｎｎａ　Ａｂ－ｉｎｉｔｉｏ　Ｓｉｍｕｌａｔｉｏｎ　Ｐａｃｋａｇｅ（ＶＡＳＰ）を用いることができる。計算条件の一例は次のとおりとすることができる。
　平面波基底関数のカットオフエネルギー：４００ｅＶ
　交換相関相互作用の近似法：ＧＧＡ＋Ｕ
　擬ポテンシャル：ＰＡＷ（ＰＢＥｓｏｌ）
　ｋ点：ガンマ点
　エネルギーｓｍｅａｒｉｎｇ：ガウシアン法 In the first-principles calculation in "(2) Determination of atomic arrangement", for example, the calculation software Vienna Ab-initio Simulation Package (VASP) can be used. An example of the calculation condition can be as follows.
Cut-off energy of plane wave basis set: 400eV
Approximation of exchange correlation interaction: GGA + U
Pseudopotential: PAW (PBEsol)
k point: gamma point energy smearing: Gaussian method
（３）条件Ａ及び条件Ｂの検討
　上記「（２）原子配列の決定」の結果における構造安定性の高い例えば上位５つの構造（原子配列）を対象に、自由エネルギー値、各イオンの電荷等を正確に計算するために再度第一原理計算を行い、条件Ａ及び条件Ｂを満たすか否かを検討する。 (3) Examination of conditions A and B For example, the top five structures (atomic arrangements) with high structural stability in the result of the above "(2) Determination of atomic arrangement", free energy value, charge of each ion, etc. In order to calculate accurately, the first-principles calculation is performed again, and it is examined whether or not the conditions A and B are satisfied.
　「（３）条件Ａ及び条件Ｂの検討」における第一原理計算にあたっては、例えば、計算ソフトウェアＶｉｅｎｎａ　Ａｂ－ｉｎｉｔｉｏ　Ｓｉｍｕｌａｔｉｏｎ　Ｐａｃｋａｇｅ（ＶＡＳＰ）を用いることができる。計算条件の一例は次のとおりとすることができる。ｋ点はｋ－ｒｅｓｏｌｕｔｉｏｎの値が１０００程度となるように設定する。ｋ－ｒｅｓｏｌｕｔｉｏｎはモデル中の原子数とａ、ｂ、ｃ軸方向のｋ点との積である。
　平面波基底関数のカットオフエネルギー：５２０ｅＶ
　交換相関相互作用の近似法：ＧＧＡ＋Ｕ
　擬ポテンシャル：ＰＡＷ（ＰＢＥｓｏｌ）
　ｋ点：ｋ－ｒｅｓｏｌｕｔｉｏｎ≒１０００
　エネルギーｓｍｅａｒｉｎｇ：ガウシアン法 In the first-principles calculation in "(3) Examination of condition A and condition B", for example, the calculation software Vienna Ab-initio Simulation Package (VASP) can be used. An example of the calculation condition can be as follows. The k point is set so that the value of k-resolution is about 1000. The k-resolution is the product of the number of atoms in the model and the k points in the a, b, and c axis directions.
Cut-off energy of plane wave basis set: 520eV
Approximation of exchange correlation interaction: GGA + U
Pseudopotential: PAW (PBEsol)
k point: k-resolution ≒ 1000
Energy smearing: Gaussian method
　３ｄ軌道が最外殻軌道であり、安定とされる価数のカチオンの状態で３ｄ軌道が閉殻でなく、３ｄ軌道に電子が存在する遷移金属元素であるバナジウム、クロム、マンガン、鉄、コバルト及びニッケルを含む材料の第一原理計算については、表１に示したハバードのＵｅｆｆ値を計算条件として使用することができる。これによりｄ軌道における電子の局在化効果が計算に反映される。表１に示したハバードのＵｅｆｆ値は、結晶構造データベースＭａｔｅｒｉａｌｓ　Ｐｒｏｊｅｃｔ（ｈｔｔｐｓ：／／ｍａｔｅｒｉａｌｓｐｒｏｊｅｃｔ．ｏｒｇ／＃ｓｅａｒｃｈ／ｍａｔｅｒｉａｌｓ）において実施された第一原理計算の計算条件より引用したものである（２０２０年５月１５日時点）。データベースにおいて、バナジウム、クロム、マンガン、鉄、コバルト及びニッケルを含む材料を検索することでＵｅｆｆ値を取得できる。 The 3d orbital is the outermost shell orbital, and the 3d orbital is not a closed shell in the state of a cation with a stable valence, and the transition metal elements vanadium, chromium, manganese, iron, cobalt and cobalt in which electrons exist in the 3d orbital. For the first-principles calculation of nickel-containing materials, the Hubbard Ueff value shown in Table 1 can be used as a calculation condition. As a result, the effect of electron localization in the d-orbital is reflected in the calculation. The Hubbard Ueff values shown in Table 1 are taken from the calculation conditions of the first-principles calculation carried out in the crystal structure database Materials Project (https://materialsproject.org/#search/materials) (2020). As of May 15, 2014). The Ueff value can be obtained by searching the database for materials containing vanadium, chromium, manganese, iron, cobalt and nickel.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　条件Ａに関し、候補酸化物の所定の充電状態での全ての第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比を求める。所定の充電状態は、第一置換元素の種類等に応じて適宜設定してよいが、例えば４００ｍＡｈ／ｇまで充電した状態とすることができる。上記酸素の配位数が４配位である第一置換元素の存在比が所定値以上である場合、条件Ａを満たすとする。上記条件Ａの所定値（閾値）は、第一置換元素の種類等に応じて適宜設定してよいが、例えば０．５３とすることができ、０．６、０．７等であってもよい。 Regarding condition A, the abundance ratio of the first substituent having an oxygen coordination number of four to all the first substituents of the candidate oxide in a predetermined charged state is obtained. The predetermined charging state may be appropriately set according to the type of the first substitution element and the like, but can be, for example, a state of charging up to 400 mAh / g. When the abundance ratio of the first substituent having four coordination numbers of oxygen is a predetermined value or more, the condition A is satisfied. The predetermined value (threshold value) of the above condition A may be appropriately set according to the type of the first substitution element and the like, but may be, for example, 0.53, even if it is 0.6, 0.7 or the like. good.
　条件Ｂに関し、候補酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比を求める。所定の充電状態は、第一置換元素の種類等に応じて適宜設定してよいが、例えば４００ｍＡｈ／ｇまで充電した状態とすることができる。条件Ａと条件Ｂにおける充電状態は同じであっても異なっていてもよいが、同じであることが好ましい。また、上記電荷は、Ｂａｄｅｒ電荷解析法により求まる電荷（Ｂａｄｅｒ　ｃｈａｒｇｅ）である。この電荷が－０．５より大きい酸素の存在比が所定値以下である場合、条件Ｂを満たすこととする。上記条件Ｂの所定値（閾値）は、第一置換元素の種類等に応じて適宜設定してよいが、例えば０．１１とすることができ、０．１０、０．０８、０．０６、０．０４等であってもよい。 Regarding condition B, the abundance ratio of oxygen having a charge greater than -0.5 with respect to all oxygen of the candidate oxide in a predetermined charged state is obtained. The predetermined charging state may be appropriately set according to the type of the first substitution element and the like, but can be, for example, a state of charging up to 400 mAh / g. The charging states under condition A and condition B may be the same or different, but are preferably the same. Further, the above-mentioned charge is a charge (Bader charge) obtained by the Bader charge analysis method. When the abundance ratio of oxygen having an electric charge greater than −0.5 is equal to or less than a predetermined value, the condition B is satisfied. The predetermined value (threshold value) of the above condition B may be appropriately set according to the type of the first substitution element and the like, but may be, for example, 0.11, 0.10, 0.08, 0.06, etc. It may be 0.04 mag.
　上記条件Ａ及び条件Ｂを満たす候補酸化物に含まれる第一置換元素及び第二置換元素を、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質に含有される酸化物に好適な置換元素の組み合わせとして選択することができる。 The first and second substituents contained in the candidate oxides satisfying the above conditions A and B are suitable for oxides contained in the positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large. It can be selected as a combination of substituents.
＜正極活物質（Ａ）＞
　本発明の一実施形態に係る正極活物質（Ａ）は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質である。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること <Positive electrode active material (A)>
The positive electrode active material (A) according to the embodiment of the present invention contains lithium, a first substitution element and a second substitution element, and contains an oxide having an inverted fluorite-type crystal structure, and the first substitution is described above. The element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups, and the second substitution element is any of the 2nd to 5th groups and the 12th to 16th groups. A positive electrode which is an element other than nitrogen, oxygen, sulfur and selenium belonging to the above, and is a combination of the first substitution element and the second substitution element in which the calculation result based on the first principle calculation satisfies the following conditions a and b. It is an active material.
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　本発明の一実施形態に係る正極活物質（Ａ）は、この正極活物質（Ａ）に含有される「リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物」の組成に基づいて第一原理計算を行った結果が上記条件ａ及び条件ｂを満たすものであってよい。換言すれば、本発明の一実施形態に係る正極活物質（Ａ）は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記酸化物が、第一原理計算に基づく計算結果が上記条件ａ及び条件ｂを満たすものである正極活物質であってよい。 The positive electrode active material (A) according to one embodiment of the present invention contains "lithium, a first-substituted element and a second-substituted element" contained in the positive electrode active material (A), and has an inverted fluorite-type crystal structure. The result of the first-principles calculation based on the composition of the "oxide having" may satisfy the above conditions a and b. In other words, the positive electrode active material (A) according to the embodiment of the present invention contains lithium, a first-substituted element and a second-substituted element, and contains an oxide having an inverted fluorite-type crystal structure. The first substitution element is an element other than technetium and tungsten belonging to any of the 6th to 11th groups, and the second substitution element is the 2nd to 5th group and the 12th to 16th group. It is an element other than nitrogen, oxygen, sulfur and selenium that belongs to any of the groups, and the above oxide is a positive electrode active material for which the calculation result based on the first-principles calculation satisfies the above conditions a and b. It's okay.
　当該正極活物質（Ａ）は、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。 The positive electrode active material (A) has a high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency is likely to be maintained even after repeated charging and discharging.
　当該正極活物質（Ａ）を特定するための第一原理計算は、計算ソフトウェアＶｉｅｎｎａ　Ａｂ－ｉｎｉｔｉｏ　Ｓｉｍｕｌａｔｉｏｎ　Ｐａｃｋａｇｅ（ＶＡＳＰ）を用いる。計算条件は「置換元素の選択方法」の一実施形態として上述した計算条件を採用する。 The calculation software Vienna Ab-initio Simulation Package (VASP) is used for the first-principles calculation for specifying the positive electrode active material (A). As the calculation condition, the above-mentioned calculation condition is adopted as one embodiment of the "method for selecting a substitution element".
　なお、対象とする正極活物質の原子組成に基づいて、まず、上記「（２）原子配列の決定」の方法に沿って、安定な原子配列を計算する。このときの条件は、「（２）原子配列の決定」の説明において具体的に挙げた条件を採用する。そして、得られた構造安定性の高い上位５つの構造（モデル）に基づいて、上記した「（３）条件Ａ及び条件Ｂの検討」に記載の方法に沿った検討を行う。このとき、上記「（３）条件Ａ及び条件Ｂの検討」に記載の具体的に挙げた条件を採用した上で、上記条件Ａ及び条件Ｂにおける所定の充電状態を４００ｍＡｈ／ｇまで充電した状態とし、上記条件Ａにおける上記存在比の所定値を０．５３とし、上記条件Ｂにおける上記存在比の所定値を０．１１とし、条件ａ及び条件ｂを満たすか否かを検討する。条件ａ及び条件ｂに係る各存在比の算出は、以下の方法で行う。
・条件ａ
　第一置換元素を中心として、半径２．５Å以内の空間に存在する酸素数を数えることで、第一置換元素に対する酸素の配位数を算出する。この評価を５つの全モデル中に含まれる全ての第一置換元素に対して行い、全ての第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比を算出する。
・条件ｂ
　Ｂａｄｅｒ電荷解析法を用いて、５つの全モデル中の全ての酸素の電荷を算出する。そして、全ての酸素に対する、電荷が－０．５より大きい酸素の存在比を算出する。 In addition, based on the atomic composition of the target positive electrode active material, first, a stable atomic arrangement is calculated according to the method of the above-mentioned "(2) determination of atomic arrangement". As the conditions at this time, the conditions specifically mentioned in the explanation of "(2) Determination of atomic arrangement" are adopted. Then, based on the obtained top five structures (models) with high structural stability, the examination is carried out according to the method described in the above-mentioned "(3) Examination of condition A and condition B". At this time, after adopting the specifically mentioned conditions described in "(3) Examination of condition A and condition B", the predetermined charging state under the above condition A and condition B is charged to 400 mAh / g. Then, the predetermined value of the abundance ratio in the condition A is set to 0.53, the predetermined value of the abundance ratio in the condition B is set to 0.11, and it is examined whether or not the condition a and the condition b are satisfied. The calculation of each abundance ratio according to the condition a and the condition b is performed by the following method.
・ Condition a
By counting the number of oxygen existing in the space within a radius of 2.5 Å with the first substituted element as the center, the coordination number of oxygen with respect to the first substituted element is calculated. This evaluation was performed for all the first substituted elements contained in all five models, and the abundance ratio of the first substituted element having an oxygen coordination number of four to all the first substituted elements was calculated. do.
・ Condition b
The Bader charge analysis method is used to calculate the charge of all oxygen in all five models. Then, the abundance ratio of oxygen having a charge greater than −0.5 is calculated for all oxygen.
　条件ａにおける酸素の配位数が４配位である第一置換元素の存在比は０．５３以上であり、０．６以上が好ましく、０．７以上がより好ましい。このような場合、酸素レドックス反応を発現させるための触媒活性能の低下がより抑えられ、充電電気量が比較的大きい場合のクーロン効率がより高まり、充放電を繰り返してもこの高いクーロン効率がより維持されやすくなる。上記酸素の配位数が４配位である第一置換元素の存在比の上限は１であってもよく、０．９５又は０．９であってもよい。 The abundance ratio of the first substituent having an oxygen coordination number of 4 under the condition a is 0.53 or more, preferably 0.6 or more, and more preferably 0.7 or more. In such a case, the decrease in the catalytic activity for expressing the oxygen redox reaction is further suppressed, the Coulomb efficiency is further increased when the amount of charging electricity is relatively large, and this high Coulomb efficiency is further enhanced even if charging and discharging are repeated. It will be easier to maintain. The upper limit of the abundance ratio of the first substituent having four coordination numbers of oxygen may be 1, and may be 0.95 or 0.9.
　また、条件ｂにおける電荷が－０．５より大きい酸素の存在比は０．１１以下であり、０．１０以下が好ましく、０．０８、０．０６又は０．０４以下がより好ましい。このような場合、酸素ガスの放出がより抑制され、充電電気量が比較的大きい場合のクーロン効率がより高まり、充放電を繰り返してもこの高いクーロン効率がより維持されやすくなる。上記電荷が－０．５より大きい酸素の存在比の下限は０であってもよく、０．０１であってもよい。 Further, the abundance ratio of oxygen having a charge greater than −0.5 under condition b is 0.11 or less, preferably 0.10 or less, and more preferably 0.08, 0.06 or 0.04 or less. In such a case, the release of oxygen gas is further suppressed, the Coulomb efficiency when the amount of charging electricity is relatively large is further increased, and this high Coulomb efficiency is more likely to be maintained even after repeated charging and discharging. The lower limit of the abundance ratio of oxygen having an electric charge greater than −0.5 may be 0 or 0.01.
　第一置換元素は、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であれば特に限定されないが、コバルト、鉄、銅、マンガン、ニッケル、クロム又はこれらの組み合わせが好ましく、コバルトを含むことがより好ましく、コバルトであることがさらにより好ましい。 The first substitution element is not particularly limited as long as it is an element other than technetium and tungsten belonging to any of Group 6 to Group 11, but cobalt, iron, copper, manganese, nickel, chromium or a combination thereof is preferable. , Cobalt is more preferred, and cobalt is even more preferred.
　第二置換元素は、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であれば特に限定されないが、構造安定性を高めるなどの観点から、これらの中でも、第２族から第４族、及び第１３族から第１５族のいずれかに属する元素が好ましく、第１３族から第１５族のいずれかに属する元素がより好ましい場合がある。 The second substitution element is not particularly limited as long as it is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16, but enhances structural stability. From these viewpoints, among these, elements belonging to any of Group 2 to Group 4 and Group 13 to Group 15 are preferable, and elements belonging to any of Group 13 to Group 15 are more preferable. In some cases.
　また、第二置換元素は、構造安定性を高めるなどの観点から、酸化物中でのカチオンの状態におけるシャノンの有効イオン半径が０．６０Å未満である元素が好ましく、０．５０Å未満である元素がより好ましい場合があり、０．４０Å未満である元素がさらに好ましい場合もある。具体的な第二置換元素としては、ホウ素（Ｂ３＋　０．１１Å；シャノンの有効イオン半径、以下同様）、炭素（Ｃ４＋　０．１５Å）、マグネシウム（Ｍｇ２＋　０．５７Å）、ケイ素（Ｓｉ４＋　０．２６Å）、リン（Ｐ５＋　０．１７Å）、チタン（Ｔｉ４＋　０．４２Å）、ガリウム（Ｇａ３＋　０．４７Å）、スズ（Ｓｎ４＋　０．５５Å）又はこれらの組み合わせが好ましく、条件ｂに係る電荷が－０．５より大きい酸素の存在比がより低くなる傾向にあるホウ素、マグネシウム、ケイ素、チタン、ガリウム又はこれらの組み合わせがより好ましく、ホウ素、ケイ素、ガリウム又はこれらの組み合わせがさらに好ましい。 Further, the second substituent is preferably an element having an effective ionic radius of Shannon of less than 0.60 Å in a cation state in the oxide, preferably an element having a radius of less than 0.50 Å, from the viewpoint of enhancing structural stability. May be more preferred, and elements less than 0.40 Å may be even more preferred. Specific second substitution elements include boron (B 3+ 0.11 Å; Shannon's effective ionic radius, the same applies hereinafter), carbon (C 4 + 0.15 Å), magnesium (Mg 2 + 0.57 Å), and silicon (Si 4 + ). 0.26 Å), phosphorus (P 5 + 0.17 Å), titanium (Ti 4 + 0.42 Å), gallium (Ga 3 + 0.47 Å), tin (Sn 4 + 0.55 Å) or a combination thereof is preferable, and the condition b is satisfied. Boron, magnesium, silicon, titanium, gallium or a combination thereof, which tends to have a lower abundance ratio of oxygen having a charge of more than −0.5, is more preferable, and boron, silicon, gallium or a combination thereof is further preferable.
　上記酸化物中の第一置換元素（Ｉ）と第二置換元素（ＩＩ）との合計含有量に対する第二置換元素（ＩＩ）の含有量のモル比率（ＩＩ／（Ｉ＋ＩＩ））は特に限定されないが、例えば０．０１以上０．８以下であり、０．０５以上０．６以下が好ましく、０．１以上０．５以下がより好ましく、０．１５以上０．４以下がさらに好ましく、０．２以上０．３以下がよりさらに好ましい場合もある。上記第二置換元素の含有量のモル比率（ＩＩ／（Ｉ＋ＩＩ））を上記範囲とすることで、結晶構造の安定性が高まり、その結果、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 The molar ratio (II / (I + II)) of the content of the second substituent (II) to the total content of the first substituted element (I) and the second substituted element (II) in the oxide is not particularly limited. However, for example, it is 0.01 or more and 0.8 or less, preferably 0.05 or more and 0.6 or less, more preferably 0.1 or more and 0.5 or less, further preferably 0.15 or more and 0.4 or less, and 0. .2 or more and 0.3 or less may be even more preferable. By setting the molar ratio (II / (I + II)) of the content of the second substituent in the above range, the stability of the crystal structure is enhanced, and as a result, the Coulomb efficiency is further enhanced and charging / discharging is repeated. Coulomb efficiency is also easier to maintain.
　上記酸化物中のリチウムと第一置換元素と第二置換元素との合計含有量に対する第一置換元素と第二置換元素との合計含有量のモル比率（（Ｉ＋ＩＩ）／（Ｌｉ＋Ｉ＋ＩＩ））は特に限定されないが、例えば０．０５以上０．３以下が好ましく、０．１以上０．２以下がより好ましく、０．１４以上０．１６以下がさらに好ましい。上記モル比率（（Ｉ＋ＩＩ）／（Ｌｉ＋Ｉ＋ＩＩ））は、Ｌｉ２Ｏに対する第一置換元素と第二置換元素との含有量の目安となり、上記モル比率（（Ｉ＋ＩＩ）／（Ｌｉ＋Ｉ＋ＩＩ））が上記範囲であることで、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 The molar ratio ((I + II) / (Li + I + II)) of the total content of the first substituent and the second substituted element to the total content of lithium, the first substituted element and the second substituted element in the oxide is particularly high. Although not limited, for example, 0.05 or more and 0.3 or less is preferable, 0.1 or more and 0.2 or less is more preferable, and 0.14 or more and 0.16 or less is further preferable. The molar ratio ((I + II) / (Li + I + II)) serves as a guide for the content of the first and second substituents on Li 2O , and the molar ratio ((I + II) / (Li + I + II)) is in the above range. Therefore, the Coulomb efficiency is further increased, and it becomes easier to maintain the Coulomb efficiency when charging and discharging are repeated.
　上記酸化物は、リチウム、酸素、第一置換元素及び第二置換元素以外の他の元素を含んでいてもよい。但し、上記酸化物を構成する全元素の合計含有量に対する上記他の元素の含有量のモル比率は、０．１以下が好ましく、０．０１以下がより好ましい。上記酸化物は、リチウム、酸素、第一置換元素及び第二置換元素から実質的に構成されていてよい。上記酸化物が、リチウム、酸素、第一置換元素及び第二置換元素から実質的に構成されていることで、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 The oxide may contain elements other than lithium, oxygen, a first-substituted element and a second-substituted element. However, the molar ratio of the contents of the other elements to the total content of all the elements constituting the oxide is preferably 0.1 or less, more preferably 0.01 or less. The oxide may be substantially composed of lithium, oxygen, a first-substituted element and a second-substituted element. Since the oxide is substantially composed of lithium, oxygen, a first-substituted element and a second-substituted element, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained. ..
　上記酸化物における酸素の含有量としては特に限定されず、通常、リチウム、第一置換元素及び第二置換元素等の組成比やこれらの元素の価数などから決定される。但し、化学量論比において酸素不足又は酸素過多の酸化物となっていてもよい。 The oxygen content in the above oxide is not particularly limited, and is usually determined from the composition ratio of lithium, the first substituted element, the second substituted element, etc., the valence of these elements, and the like. However, it may be an oxide with insufficient oxygen or excess oxygen in the stoichiometric ratio.
　なお、本明細書における酸化物の組成比は、充放電を行っていない酸化物、あるいは次の方法により完全放電状態とした酸化物における組成比をいう。まず、非水電解質蓄電素子を、０．０５Ｃの電流で通常使用時の充電終止電圧となるまで定電流充電し、満充電状態とする。３０分の休止後、０．０５Ｃの電流で通常使用時の下限電圧まで定電流放電する。解体し、正極を取り出し、金属リチウム電極を対極とした試験電池を組み立て、正極合剤１ｇあたり１０ｍＡの電流で、端子間電圧が１．５Ｖとなるまで定電流放電を行い、正極を完全放電状態に調整する。再解体し、正極を取り出す。取り出した正極から、酸化物を採取する。ここで、通常使用時とは、当該非水電解質蓄電素子について推奨され、又は指定される充放電条件を採用して当該非水電解質蓄電素子を使用する場合であり、当該非水電解質蓄電素子のための充電器が用意されている場合は、その充電器を適用して当該非水電解質蓄電素子を使用する場合をいう。 The composition ratio of the oxide in the present specification means the composition ratio of the oxide that has not been charged and discharged, or the oxide that has been completely discharged by the following method. First, the non-aqueous electrolyte power storage element is constantly charged with a current of 0.05 C until the charge end voltage at the time of normal use is reached, and the state is fully charged. After a 30-minute pause, a constant current discharge is performed with a current of 0.05 C to the lower limit voltage during normal use. Disassemble, take out the positive electrode, assemble a test battery with a metal lithium electrode as the counter electrode, and perform constant current discharge with a current of 10 mA per 1 g of the positive electrode mixture until the voltage between terminals reaches 1.5 V, and the positive electrode is in a completely discharged state. Adjust to. Re-disassemble and take out the positive electrode. Oxide is collected from the removed positive electrode. Here, the normal use is a case where the non-aqueous electrolyte storage element is used by adopting the charge / discharge conditions recommended or specified for the non-aqueous electrolyte storage element, and the non-aqueous electrolyte power storage element is used. When a charger for this purpose is prepared, it means a case where the charger is applied to use the non-aqueous electrolyte power storage element.
　上記酸化物の組成式は、下記式（１）で表されることが好ましい。
　［Ｌｉ２－２ｚＭ２ｘＡ２ｙ］Ｏ　・・・（１）
　上記式（１）中、Ｍは、第一置換元素である。Ａは、第二置換元素である。ｘ、ｙ及びｚは、下記式（ａ）から（ｃ）を満たす。
　０＜ｘ＜１　・・・（ａ）
　０＜ｙ＜１　・・・（ｂ）
　ｘ＋ｙ≦ｚ＜１　・・・（ｃ） The composition formula of the oxide is preferably represented by the following formula (1).
[Li 2-2z M 2x A 2y ] O ... (1)
In the above formula (1), M is a first substitution element. A is a second substitution element. x, y and z satisfy the following formulas (a) to (c).
0 <x <1 ... (a)
0 <y <1 ... (b)
x + y ≦ z <1 ... (c)
　上記式（１）中のＭは、Ｃｏ、Ｆｅ、Ｃｕ、Ｍｎ、Ｎｉ、Ｃｒ又はこれらの組み合わせが好ましく、Ｃｏがより好ましい。 M in the above formula (1) is preferably Co, Fe, Cu, Mn, Ni, Cr or a combination thereof, and Co is more preferable.
　上記式（１）中のＡは、Ｂ、Ｃ、Ｍｇ、Ｓｉ、Ｐ、Ｔｉ、Ｇａ、Ｓｎ又はこれらの組み合わせが好ましい。 A in the above formula (1) is preferably B, C, Mg, Si, P, Ti, Ga, Sn or a combination thereof.
　上記式（１）中のｘは、Ｌｉ２Ｏに対して添加された第一置換元素の含有量に関係し、上記式（ａ）を満たす。ｘは、０．０１以上０．５以下が好ましく、０．０３以上０．３以下がより好ましく、０．０５以上０．２以下がさらに好ましく、０．０６以上０．１５以下がよりさらに好ましく、０．０８以上０．１２以下が特に好ましい。ｘを上記範囲内とすることで、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 The x in the above formula (1) is related to the content of the first substituent added to Li 2 O and satisfies the above formula (a). x is preferably 0.01 or more and 0.5 or less, more preferably 0.03 or more and 0.3 or less, further preferably 0.05 or more and 0.2 or less, and further preferably 0.06 or more and 0.15 or less. , 0.08 or more and 0.12 or less is particularly preferable. By setting x within the above range, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained.
　上記式（１）中のｙは、Ｌｉ２Ｏに対して添加された第二置換元素の含有量に関係し、上記式（ｂ）を満たす。ｙは、０．００１以上０．５以下が好ましく、０．００５以上０．２以下がより好ましく、０．０１以上０．１以下がさらに好ましく、０．０２以上０．０４以下が特に好ましい。ｙを上記範囲内とすることで、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 Y in the above formula (1) is related to the content of the second substituent added to Li 2 O and satisfies the above formula (b). y is preferably 0.001 or more and 0.5 or less, more preferably 0.005 or more and 0.2 or less, further preferably 0.01 or more and 0.1 or less, and particularly preferably 0.02 or more and 0.04 or less. By setting y within the above range, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained.
　上記式（１）中のｚは、Ｌｉの含有量に関係し、上記式（ｃ）を満たす。ｚは、第一置換元素及び第二置換元素の価数等によって決定され得る。ｚは、０．１以上０．５以下が好ましく、０．２以上０．４以下がより好ましく、０．２６以上０．３２以下がさらに好ましく、０．２７以上０．３０以下が特に好ましい。 Z in the above formula (1) is related to the Li content and satisfies the above formula (c). z can be determined by the valences of the first and second substitution elements and the like. z is preferably 0.1 or more and 0.5 or less, more preferably 0.2 or more and 0.4 or less, further preferably 0.26 or more and 0.32 or less, and particularly preferably 0.27 or more and 0.30 or less.
　上記式（１）のｘ及びｙは、下記式（ｄ）を満たすことがより好ましい。
  ０．０１≦ｙ／（ｘ＋ｙ）≦０．８　・・・（ｄ）
　上記式（ｄ）におけるｙ／（ｘ＋ｙ）は、当該正極活物質における第一置換元素と第二置換元素との合計含有量に対する第二置換元素の含有量のモル比率（ＩＩ／（Ｉ＋ＩＩ））である。ｙ／（ｘ＋ｙ）は、０．０５以上０．６以下がより好ましく、０．１以上０．５以下がさらに好ましく、０．１５以上０．４以下がよりさらに好ましく、０．２以上０．３以下がよりさらに好ましい場合もある。ｙ／（ｘ＋ｙ）を上記範囲内とすることで、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。 It is more preferable that x and y of the above formula (1) satisfy the following formula (d).
0.01 ≤ y / (x + y) ≤ 0.8 ... (d)
Y / (x + y) in the above formula (d) is the molar ratio of the content of the second substituent to the total content of the first substituted element and the second substituted element in the positive electrode active material (II / (I + II)). Is. y / (x + y) is more preferably 0.05 or more and 0.6 or less, further preferably 0.1 or more and 0.5 or less, further preferably 0.15 or more and 0.4 or less, and 0.2 or more and 0. In some cases, 3 or less is even more preferable. By setting y / (x + y) within the above range, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained.
　上記酸化物のＣｕＫα線を用いたエックス線回折図において、回折角２θが３３°付近（例えば３０°以上３５°以下の範囲）の回折ピークの半値幅は０．３°以上が好ましく、０．５°以上がより好ましく、０．６°以上がさらに好ましい。回折角２θが３３°付近の回折ピークの半値幅が上記下限以上である場合、クーロン効率がより高まり、充放電を繰り返した場合のクーロン効率もより維持されやすくなる。なお、後述するメカノケミカル法により処理する製造方法によって当該正極活物質（酸化物）を製造することで、このような回折ピークの半値幅が大きいものとなる傾向がある。回折角２θが３３°付近の回折ピークの半値幅は、例えば５°以下であってもよく、３°以下であってもよく、２°以下であってもよい。 In the X-ray diffraction diagram using CuKα rays of the oxide, the half width of the diffraction peak at a diffraction angle 2θ near 33 ° (for example, in the range of 30 ° or more and 35 ° or less) is preferably 0.3 ° or more, and 0.5 °. ° or more is more preferable, and 0.6 ° or more is further preferable. When the full width at half maximum of the diffraction peak near the diffraction angle 2θ is 33 ° or more, the coulomb efficiency is further increased, and the coulomb efficiency when charging and discharging are repeated is more likely to be maintained. By manufacturing the positive electrode active material (oxide) by a manufacturing method that is treated by the mechanochemical method described later, the half-value width of such a diffraction peak tends to be large. The half width of the diffraction peak in which the diffraction angle 2θ is around 33 ° may be, for example, 5 ° or less, 3 ° or less, or 2 ° or less.
　当該正極活物質（Ａ）は、上記酸化物以外の他の成分を含んでいてもよい。但し、当該正極活物質（Ａ）における上記酸化物の含有量は５０質量％以上が好ましく、９０質量％以上がより好ましく、９９質量％以上がさらに好ましい。 The positive electrode active material (A) may contain components other than the above oxides. However, the content of the oxide in the positive electrode active material (A) is preferably 50% by mass or more, more preferably 90% by mass or more, still more preferably 99% by mass or more.
＜正極活物質（Ｂ）＞
　本発明の他の実施形態に係る正極活物質（Ｂ）は、本発明の一実施形態に係る置換元素の選択方法を用いて選択された第一置換元素及び第二置換元素並びにリチウムを含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、上記条件Ａ及び条件Ｂにおける所定の充電状態が４００ｍＡｈ／ｇまで充電した状態であり、上記条件Ａにおける上記存在比の所定値が０．５３であり、上記条件Ｂにおける上記存在比の所定値が０．１１である正極活物質である。 <Positive electrode active material (B)>
The positive electrode active material (B) according to another embodiment of the present invention contains a first substituent, a second substituted element and lithium selected by using the method for selecting a substituent according to one embodiment of the present invention. Moreover, it contains an oxide having an inverted fluorite-type crystal structure, and the predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the above condition A is 0. It is a positive electrode active material having a value of .53 and a predetermined value of the abundance ratio under the condition B of 0.11.
　当該正極活物質（Ｂ）は、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。当該正極活物質（Ｂ）に含有される酸化物等の具体的形態及び好適形態は、正極活物質（Ａ）に含有される酸化物等と同様である。 The positive electrode active material (B) has a high coulombic efficiency even when the amount of charging electricity is relatively large, and this high coulombic efficiency is likely to be maintained even after repeated charging and discharging. The specific form and suitable form of the oxide or the like contained in the positive electrode active material (B) are the same as those of the oxide or the like contained in the positive electrode active material (A).
＜正極活物質の製造方法＞
　本発明の一実施形態に係る正極活物質（Ａ）及び正極活物質（Ｂ）は、例えば以下の本発明の一実施形態に係る正極活物質の製造方法（Ａ）から（Ｃ）により製造することができる。 <Manufacturing method of positive electrode active material>
The positive electrode active material (A) and the positive electrode active material (B) according to the embodiment of the present invention are produced, for example, by the following methods (A) to (C) for producing the positive electrode active material according to the embodiment of the present invention. be able to.
　本発明の一実施形態に係る正極活物質の製造方法（Ａ）は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質を製造する方法であって、本発明の一実施形態に係る置換元素の選択方法を用いて選択された上記第一置換元素及び上記第二置換元素を含む材料を処理することを備える。 The method (A) for producing a positive electrode active material according to an embodiment of the present invention is a positive electrode activity containing lithium, a first-substituted element and a second-substituted element, and an oxide having an inverted fluorite-type crystal structure. A method for producing a substance, comprising treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to an embodiment of the present invention.
　当該正極活物質の製造方法（Ａ）をより具体化した製造方法である、本発明の他の実施形態に係る正極活物質の製造方法（Ｂ）は、本発明の一実施形態に係る置換元素の選択方法により、上記第一置換元素及び上記第二置換元素の組み合わせを選択すること（選択工程）、及びリチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理すること（処理工程）を備える。 The method for producing a positive electrode active material (B) according to another embodiment of the present invention, which is a production method that embodies the method for producing a positive electrode active material (A), is a substitution element according to an embodiment of the present invention. The combination of the first substitution element and the second substitution element is selected by the selection method (selection step), and the material containing lithium, oxygen, the first substitution element and the second substitution element is subjected to the mechanochemical method. (Processing process) is provided.
　また、上記の選択工程を備えない製造方法によって当該正極活物質を製造することもできる。このような製造方法である本発明の他の実施形態に係る正極活物質の製造方法（Ｃ）は、リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質の製造方法であって、リチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理すること（処理工程）を備え、上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである。
　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること Further, the positive electrode active material can also be manufactured by a manufacturing method that does not include the above-mentioned selection step. The method (C) for producing a positive electrode active material according to another embodiment of the present invention, which is such a production method, contains lithium, a first-substituted element and a second-substituted element, and has an inverted fluorite-type crystal structure. A method for producing a positive electrode active material containing an oxide, which comprises treating a material containing lithium, oxygen, the first substitution element and the second substitution element by a mechanochemical method (treatment step). The first substitution element is an element other than technetium and tungsten, which belongs to any of the 6th to 11th groups, and the second substitution element is the 2nd to 5th group and the 12th to 16th group. A combination of the first substitution element and the second substitution element, which are elements other than nitrogen, oxygen, sulfur and selenium, which belong to any of the above, and the calculation result based on the first principle calculation satisfies the following conditions a and b. Is.
Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
　これらの製造方法（Ａ）から（Ｃ）によれば、所定の元素を含む一種又は複数種の材料をメカノケミカル法によって処理することにより、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返した場合のクーロン効率も維持されやすい正極活物質を得ることができる。 According to these production methods (A) to (C), by treating one or more kinds of materials containing a predetermined element by the mechanochemical method, the Coulomb efficiency is high even when the amount of charging electricity is relatively large. It is possible to obtain a positive electrode active material whose Coulomb efficiency is easily maintained when charging and discharging are repeated.
　これらの製造方法において選択される又はメカノケミカル法による処理に供される材料に含まれる第一置換元素及び第二置換元素の具体例及び好適例は、本発明の一実施形態に係る正極活物質（Ａ）に含有される酸化物に含まれる第一置換元素及び第二置換元素の具体例及び好適例と同様である。また、これらの製造方法によって製造される正極活物質の具体例及び好適例は、本発明の一実施形態に係る正極活物質（Ａ）の具体例及び好適例と同様である。 Specific examples and suitable examples of the first-substituted element and the second-substituted element contained in the material selected in these production methods or subjected to the treatment by the mechanochemical method are the positive electrode active materials according to the embodiment of the present invention. It is the same as the specific example and the preferable example of the 1st substitution element and the 2nd substitution element contained in the oxide contained in (A). Further, specific examples and suitable examples of the positive electrode active material produced by these production methods are the same as the specific examples and suitable examples of the positive electrode active material (A) according to the embodiment of the present invention.
　メカノケミカル法（メカノケミカル処理などともいう。）とは、メカノケミカル反応を利用した合成法をいう。メカノケミカル反応とは、固体物質の破砕過程での摩擦、圧縮等の機械的エネルギーにより局部的に生じる高いエネルギーを利用する結晶化反応、固溶反応、相転移反応等の化学反応をいう。当該製造方法においては、メカノケミカル法による処理によって、Ｌｉ２Ｏの結晶構造中に第一置換元素及び第二置換元素が固溶する反応などが生じていると推測される。メカノケミカル法による処理を行う装置としては、ボールミル、ビーズミル、振動ミル、ターボミル、メカノフュージョン、ディスクミルなどの粉砕・分散機が挙げられる。これらの中でもボールミルが好ましい。ボールミルに用いるボール及びミル容器としては、タングステンカーバイド（ＷＣ）製のものや、酸化ジルコニウム（ＺｒＯ２）製のものなどを好適に用いることができる。 The mechanochemical method (also referred to as mechanochemical treatment) is a synthetic method using a mechanochemical reaction. The mechanochemical reaction refers to a chemical reaction such as a crystallization reaction, a solid solution reaction, or a phase transition reaction that utilizes high energy locally generated by mechanical energy such as friction and compression in the crushing process of a solid substance. In this production method, it is presumed that the treatment by the mechanochemical method causes a reaction in which the first-substituted element and the second-substituted element are dissolved in the crystal structure of Li 2O . Examples of the apparatus for processing by the mechanochemical method include crushing / dispersing machines such as ball mills, bead mills, vibration mills, turbo mills, mechanofusions, and disc mills. Of these, a ball mill is preferable. As the balls and mill containers used in the ball mill, those made of tungsten carbide (WC), those made of zirconium oxide (ZrO 2 ), and the like can be preferably used.
　ボールミルにより処理する場合、処理の際のミル回転数としては例えば１００ｒｐｍ以上１，０００ｒｐｍ以下とすることができる。また、処理時間としては、例えば０．１時間以上１００時間以下とすることができる。また、この処理は、アルゴン等の不活性ガス雰囲気下又は空気等の活性ガス雰囲気下で行うことができるが、不活性ガス雰囲気下で行うことが好ましい。ここで、不活性ガスとは、ボールミル処理に供される材料、及び得られる正極活物質に対して不活性なガスをいう。 When processing with a ball mill, the mill rotation speed during processing can be, for example, 100 rpm or more and 1,000 rpm or less. The processing time can be, for example, 0.1 hour or more and 100 hours or less. Further, this treatment can be carried out in an atmosphere of an inert gas such as argon or an atmosphere of an active gas such as air, but it is preferably carried out in an atmosphere of an inert gas. Here, the inert gas refers to a gas that is inert to the material to be subjected to the ball mill treatment and the obtained positive electrode active material.
　本発明の一実施形態に係る正極活物質の製造方法（Ａ）又は正極活物質の製造方法（Ｂ）により得られる正極活物質も、逆蛍石型の結晶構造を有することが好ましい。なお、本発明の一実施形態に係る正極活物質の製造方法（Ｂ）又は本発明の一実施形態に係る正極活物質の製造方法（Ｃ）のようにメカノケミカル法により処理することで、得られる正極活物質は、ＣｕＫα線を用いたエックス線回折図において、回折角２θが３３°付近の回折ピークの半値幅が０．３°以上と大きくなる傾向にある。 The positive electrode active material obtained by the method for producing a positive electrode active material (A) or the method for producing a positive electrode active material (B) according to an embodiment of the present invention also preferably has an inverted fluorite-type crystal structure. In addition, it can be obtained by treating with a mechanochemical method as in the method for producing a positive electrode active material according to an embodiment of the present invention (B) or the method for producing a positive electrode active material according to an embodiment of the present invention (C). In the X-ray diffraction diagram using CuKα rays, the positive electrode active material to be obtained tends to have a large half-value width of a diffraction peak near a diffraction angle of 2θ of 33 °, which is 0.3 ° or more.
　メカノケミカル法による処理に供される材料は、リチウム、第一置換元素及び第二置換元素のいずれか１種以上を含む酸化物が好適に用いられる。また、酸化物以外のリチウム、第一置換元素及び第二置換元素のいずれか１種以上を含む化合物やこれらの元素の単体を用いることもできる。１種又は２種以上の化合物等で構成される材料中に、リチウム、酸素、上記第一置換元素及び上記第二置換元素が含有されていればよい。 As the material to be treated by the mechanochemical method, an oxide containing at least one of lithium, a first substitution element and a second substitution element is preferably used. Further, a compound containing at least one of lithium other than an oxide, a first-substituted element and a second-substituted element, or a simple substance of these elements can also be used. Lithium, oxygen, the first substitution element and the second substitution element may be contained in the material composed of one kind or two or more kinds of compounds.
　メカノケミカル法による処理に供される好適な材料としては、（α）第一置換元素を含むリチウム遷移金属複合酸化物と第二置換元素を含む化合物とを含む混合物、及び（β）第一置換元素及び第二置換元素を含むリチウム遷移金属複合酸化物が挙げられる。これらの材料には、さらにその他の酸化物（Ｌｉ２Ｏ等）等が含まれていてよい。 Suitable materials to be subjected to the treatment by the mechanochemical method include (α) a mixture containing a lithium transition metal composite oxide containing a first substituent and a compound containing a second substituent, and (β) a first substitution. Examples include lithium transition metal composite oxides containing elements and second substituents. These materials may further contain other oxides (Li 2 O, etc.) and the like.
　リチウムの酸化物としては、Ｌｉ２Ｏが挙げられる。第一置換元素の酸化物としては、ＣｏＯ、Ｃｏ３Ｏ４、Ｆｅ２Ｏ３、ＭｎＯ２、ＮｉＯ、Ｃｕ２Ｏ、ＣｕＯ等が挙げられる。第二置換元素の酸化物又は複合酸化物としては、Ｂ２Ｏ３、ＭｇＯ、Ａｌ２ＳｉＯ５等が挙げられる。 Examples of the oxide of lithium include Li 2 O. Examples of the oxide of the first substituent include CoO, Co3O4 , Fe2O3 , MnO2 , NiO, Cu2O , CuO and the like. Examples of the oxide or composite oxide of the second substitution element include B2 O 3 , MgO, Al 2 SiO 5 and the like.
　リチウムと第一置換元素を含む酸化物（第一置換元素を含むリチウム遷移金属複合酸化物）としては、Ｌｉ６ＣｏＯ４、Ｌｉ５ＣｒＯ４、Ｌｉ５ＦｅＯ４、Ｌｉ６ＮｉＯ４、Ｌｉ６ＣｕＯ４、Ｌｉ６ＭｎＯ４、ＬｉＣｏＯ２、ＬｉＭｎＯ２、ＬｉＭｎ２Ｏ４、Ｌｉ２ＭｎＯ３、ＬｉＦｅＯ２等が挙げられる。これらの第一置換元素を含むリチウム遷移金属複合酸化物は、逆蛍石型の結晶構造を有するものであってもよく、他の結晶構造を有するものであってもよい。なお、これらのリチウム遷移金属複合酸化物は、例えばＬｉ２ＯとＣｏＯ等の第一置換元素の酸化物とを所定比率で混合し、窒素雰囲気下、空気雰囲気下等で焼成することにより得ることができる。 Oxides containing lithium and the primary substituent (lithium transition metal composite oxide containing the primary substituent) include Li 6 CoO 4 , Li 5 CrO 4 , Li 5 FeO 4 , Li 6 NiO 4 , and Li 6 CuO. 4 , Li 6 MnO 4 , LiCoO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiFeO 2 , and the like. The lithium transition metal composite oxide containing these first substituents may have an inverted fluorite-type crystal structure or may have another crystal structure. These lithium transition metal composite oxides can be obtained by mixing, for example, Li 2O and an oxide of a first substituent such as CoO at a predetermined ratio and firing in a nitrogen atmosphere, an air atmosphere, or the like. Can be done.
　リチウムと第二置換元素を含む化合物としては、Ｌｉ３ＢＯ３、Ｌｉ４Ｂ２Ｏ５、Ｌｉ６Ｂ４Ｏ９、ＬｉＢＯ２、ＬｉＢ４Ｏ７、ａＬｉ２Ｏ・ｂＢ２Ｏ３（ａ、ｂは任意の有理数）、Ｌｉ４ＣＯ４、Ｌｉ２ＭｇＯ２、Ｌｉ４ＳｉＯ４、Ｌｉ３ＰＯ４、Ｌｉ２ＴｉＯ３、Ｌｉ５ＧａＯ４、Ｌｉ４ＳｎＯ４、Ｌｉ８ＳｉＯ６、ＬｉＳｉ２ＢＯ６、ＬｉＳｉＢＯ４、Ｌｉ２ＴｉＳｉＯ５等が挙げられる。これらの化合物は、結晶質のものであってもよく、非晶質、ガラス質等のものであってもよい。上記の各化合物は、例えばＬｉ２ＯとＢ２Ｏ３等の第二置換元素を含む化合物とを所定比率で混合し、窒素雰囲気下で焼成することにより得ることができる。 Compounds containing lithium and the second substituent include Li 3 BO 3 , Li 4 B 2 O 5 , Li 6 B 4 O 9 , Li BO 2 , LiB 4 O 7 , aLi 2 O and bB 2 O 3 (a, b is an arbitrary rational number), Li 4 CO 4 , Li 2 MgO 2 , Li 4 SiO 4 , Li 3 PO 4 , Li 2 TiO 3 , Li 5 GaO 4 , Li 4 SnO 4 , Li 8 SiO 6 , LiSi 2 BO 6 , LiSiBO 4 , Li 2 TiSiO 5 and the like can be mentioned. These compounds may be crystalline, amorphous, glassy or the like. Each of the above compounds can be obtained by mixing, for example, a compound containing a second substituent such as Li 2 O and B 2 O 3 at a predetermined ratio and firing in a nitrogen atmosphere.
　第一置換元素及び第二置換元素を含むリチウム遷移金属複合酸化物としては、Ｌｉ５．５Ｃｏ０．５Ｂ０．５Ｏ４、Ｌｉ５．８Ｃｏ０．８Ｂ０．２Ｏ４等のＬｉａＭｂＡｃＯ４（Ｍは第一置換元素、Ａは第二置換元素である。０＜ａ≦６、０＜ｂ＜１、０＜ｃ＜１）で表されるリチウム遷移金属複合酸化物を挙げることができる。第一置換元素及び第二置換元素を含むリチウム遷移金属複合酸化物は、焼成法などの公知の方法により得ることができる。これらのリチウム遷移金属複合酸化物の結晶構造は特に限定されず、例えば空間群Ｐ４２／ｎｍｃに帰属可能な結晶構造、空間群Ｐｍｍｎに帰属可能な結晶構造等であってもよく、複数の結晶構造を含んでいてよい。また、これらのリチウム遷移金属複合酸化物は、結晶質に加え、非晶質やガラス質を含んでいてよい。 Lithium transition metal composite oxides containing the first and second substituents include Li 5.5 Co 0.5 B 0.5 O 4 , Li 5.8 Co 0.8 B 0.2 O 4 and the like. Li a M b A c O 4 (M is the first substitution element, A is the second substitution element. Lithium transition represented by 0 <a ≦ 6, 0 <b <1, 0 <c <1). A metal composite oxide can be mentioned. The lithium transition metal composite oxide containing the first substitution element and the second substitution element can be obtained by a known method such as a calcination method. The crystal structure of these lithium transition metal composite oxides is not particularly limited, and may be, for example, a crystal structure that can be attributed to the space group P42 / nmc, a crystal structure that can be attributed to the space group Pmmn, or the like, and a plurality of crystal structures. May include. Further, these lithium transition metal composite oxides may contain amorphous or glassy substances in addition to crystalline substances.
＜正極＞
　本発明の一実施形態に係る正極は、上述した当該正極活物質（Ａ）又は正極活物質（Ｂ）を含有する非水電解質蓄電素子用の正極である。当該正極は、正極基材、及びこの正極基材に直接又は中間層を介して配される正極活物質層を有する。 <Positive electrode>
The positive electrode according to the embodiment of the present invention is a positive electrode for a non-aqueous electrolyte power storage element containing the above-mentioned positive electrode active material (A) or positive electrode active material (B). The positive electrode has a positive electrode base material and a positive electrode active material layer arranged directly on the positive electrode base material or via an intermediate layer.
　上記正極基材は、導電性を有する。「導電性を有する」とは、ＪＩＳ－Ｈ－０５０５（１９７５年）に準拠して測定される体積抵抗率が１０７Ω・ｃｍ以下であることを意味し、「非導電性」とは、上記体積抵抗率が１０７Ω・ｃｍ超であることを意味する。正極基材の材質としては、アルミニウム、チタン、タンタル、ステンレス鋼等の金属又はそれらの合金が用いられる。これらの中でも、耐電位性、導電性の高さ及びコストのバランスからアルミニウム及びアルミニウム合金が好ましい。また、正極基材の形成形態としては、箔、蒸着膜等が挙げられ、コストの面から箔が好ましい。つまり、正極基材としてはアルミニウム箔が好ましい。なお、アルミニウム又はアルミニウム合金としては、ＪＩＳ－Ｈ－４０００（２０１４年）に規定されるＡ１０８５Ｐ、Ａ３００３Ｐ等が例示できる。 The positive electrode base material has conductivity. "Having conductivity" means that the volume resistivity measured according to JIS-H-0505 (1975) is 107 Ω · cm or less, and "non-conductive" means. It means that the volume resistivity is more than 107 Ω · cm. As the material of the positive electrode base material, metals such as aluminum, titanium, tantalum, and stainless steel or alloys thereof are used. Among these, aluminum and aluminum alloys are preferable from the viewpoint of the balance between potential resistance, high conductivity and cost. Further, examples of the formation form of the positive electrode base material include foil, a vapor-deposited film, and the like, and foil is preferable from the viewpoint of cost. That is, aluminum foil is preferable as the positive electrode base material. Examples of aluminum or aluminum alloy include A1085P and A3003P specified in JIS-H-4000 (2014).
　正極基材の平均厚さは、３μｍ以上５０μｍ以下が好ましく、５μｍ以上４０μｍ以下がより好ましく、８μｍ以上３０μｍ以下がさらに好ましく、１０μｍ以上２５μｍ以下が特に好ましい。正極基材の平均厚さを上記の範囲とすることで、正極基材の強度を高めつつ、蓄電素子の体積当たりのエネルギー密度を高めることができる。正極基材及び後述する負極基材の「平均厚さ」とは、所定の面積の基材を打ち抜いた際の打ち抜き質量を、基材の真密度及び打ち抜き面積で除した値をいう。 The average thickness of the positive electrode substrate is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 40 μm or less, further preferably 8 μm or more and 30 μm or less, and particularly preferably 10 μm or more and 25 μm or less. By setting the average thickness of the positive electrode base material in the above range, it is possible to increase the strength of the positive electrode base material and the energy density per volume of the power storage element. The "average thickness" of the positive electrode base material and the negative electrode base material described later means a value obtained by dividing the punched mass when punching a base material having a predetermined area by the true density and the punched area of the base material.
　中間層は、正極基材の表面の被覆層であり、炭素粒子等の導電性粒子を含むことで正極基材と正極活物質層との接触抵抗を低減する。中間層の構成は特に限定されず、例えば樹脂バインダー及び導電性粒子を含有する組成物により形成できる。 The intermediate layer is a coating layer on the surface of the positive electrode base material, and contains conductive particles such as carbon particles to reduce the contact resistance between the positive electrode base material and the positive electrode active material layer. The composition of the intermediate layer is not particularly limited, and can be formed by, for example, a composition containing a resin binder and conductive particles.
　正極活物質層は、正極活物質を含むいわゆる正極合剤から形成される。また、正極活物質層を形成する正極合剤は、必要に応じて導電剤、バインダー、増粘剤、フィラー等の任意成分を含む。 The positive electrode active material layer is formed from a so-called positive electrode mixture containing a positive electrode active material. Further, the positive electrode mixture forming the positive electrode active material layer contains optional components such as a conductive agent, a binder, a thickener, and a filler, if necessary.
　上記正極活物質として、上述した本発明の一実施形態に係る正極活物質（Ａ）又は正極活物質（Ｂ）を含む。正極活物質としては、本発明の一実施形態に係る正極活物質（Ａ）又は正極活物質（Ｂ）以外の公知の正極活物質が含まれていてもよい。上記正極活物質層における本発明の一実施形態に係る正極活物質（Ａ）又は正極活物質（Ｂ）の含有量は、１０質量％超が好ましく、３０質量％以上がより好ましく、５０質量％以上がさらに好ましく、７０質量％以上が特に好ましい。このように、正極活物質層中の当該正極活物質（Ａ）又は正極活物質（Ｂ）の含有割合を高めることで、正極活物質層あたりのエネルギー密度が高まり、蓄電素子のエネルギー密度を高めることができる。一方、正極活物質層における本発明の一実施形態に係る正極活物質（Ａ）又は正極活物質（Ｂ）の含有量は、９９質量％以下、９８質量％以下、９０質量％以下、又は８０質量％以下であってもよい。 The positive electrode active material includes the positive electrode active material (A) or the positive electrode active material (B) according to the above-described embodiment of the present invention. The positive electrode active material may contain a known positive electrode active material other than the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention. The content of the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention in the positive electrode active material layer is preferably more than 10% by mass, more preferably 30% by mass or more, and more preferably 50% by mass. The above is more preferable, and 70% by mass or more is particularly preferable. In this way, by increasing the content ratio of the positive electrode active material (A) or the positive electrode active material (B) in the positive electrode active material layer, the energy density per positive electrode active material layer is increased, and the energy density of the power storage element is increased. be able to. On the other hand, the content of the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention in the positive electrode active material layer is 99% by mass or less, 98% by mass or less, 90% by mass or less, or 80. It may be mass% or less.
　上記導電剤としては、導電性を有する材料であれば特に限定されない。このような導電剤としては、例えば、炭素質材料；金属；導電性セラミックス等が挙げられる。炭素質材料としては、黒鉛やカーボンブラックが挙げられる。カーボンブラックの種類としては、ファーネスブラック、アセチレンブラック、ケッチェンブラック等が挙げられる。これらの中でも、導電性及び塗工性の観点より、炭素質材料が好ましい。なかでも、アセチレンブラックやケッチェンブラックが好ましい。導電剤の形状としては、粉状、シート状、繊維状等が挙げられる。 The conductive agent is not particularly limited as long as it is a conductive material. Examples of such a conductive agent include carbonaceous materials; metals; conductive ceramics and the like. Examples of carbonaceous materials include graphite and carbon black. Examples of the type of carbon black include furnace black, acetylene black, and ketjen black. Among these, carbonaceous materials are preferable from the viewpoint of conductivity and coatability. Of these, acetylene black and ketjen black are preferable. Examples of the shape of the conductive agent include powder, sheet, and fibrous.
　上記正極活物質と導電剤とは複合化されていてもよい。複合化する方法としては、後述するような、正極活物質と導電剤を含む混合物をメカニカルミリング処理する方法等が挙げられる。 The positive electrode active material and the conductive agent may be combined. Examples of the method of compositing include a method of mechanically milling a mixture containing a positive electrode active material and a conductive agent, which will be described later.
　正極活物質層における導電剤の含有量は、１質量％以上４０質量％以下が好ましく、３質量％以上３０質量％以下がより好ましく、５質量％以上又は１０質量％以上がさらに好ましい場合もある。導電剤の含有量を上記の範囲とすることで、蓄電素子のエネルギー密度を高めることができる。 The content of the conductive agent in the positive electrode active material layer is preferably 1% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and further preferably 5% by mass or more or 10% by mass or more. .. By setting the content of the conductive agent in the above range, the energy density of the power storage element can be increased.
　上記バインダーとしては、フッ素樹脂（ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン（ＰＶＤＦ）等）、ポリエチレン、ポリプロピレン、ポリイミド等の熱可塑性樹脂；エチレン－プロピレン－ジエンゴム（ＥＰＤＭ）、スルホン化ＥＰＤＭ、スチレンブタジエンゴム（ＳＢＲ）、フッ素ゴム等のエラストマー；多糖類高分子などが挙げられる。 Examples of the binder include fluororesins (polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.), thermoplastic resins such as polyethylene, polypropylene, and polyimide; ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, and styrene. Elastomers such as butadiene rubber (SBR) and fluororubber; polysaccharide polymers and the like can be mentioned.
　正極活物質層におけるバインダーの含有量は、１質量％以上１０質量％以下が好ましく、３質量％以上９質量％以下がより好ましい。バインダーの含有量を上記の範囲とすることで、活物質を安定して保持することができる。 The content of the binder in the positive electrode active material layer is preferably 1% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 9% by mass or less. By setting the content of the binder in the above range, the active substance can be stably retained.
　上記増粘剤としては、カルボキシメチルセルロース（ＣＭＣ）、メチルセルロース等の多糖類高分子が挙げられる。また、増粘剤がリチウムと反応する官能基を有する場合、予めメチル化等によりこの官能基を失活させておくことが好ましい。 Examples of the thickener include polysaccharide polymers such as carboxymethyl cellulose (CMC) and methyl cellulose. When the thickener has a functional group that reacts with lithium, it is preferable to inactivate this functional group by methylation or the like in advance.
　上記フィラーは、特に限定されない。フィラーとしては、ポリプロピレン、ポリエチレン等のポリオレフィン、二酸化ケイ素、酸化アルミニウム、二酸化チタン、酸化カルシウム、酸化ストロンチウム、酸化バリウム、酸化マグネシウム、アルミノケイ酸塩等の無機酸化物、水酸化マグネシウム、水酸化カルシウム、水酸化アルミニウム等の水酸化物、炭酸カルシウム等の炭酸塩、フッ化カルシウム、フッ化バリウム、硫酸バリウム等の難溶性のイオン結晶、窒化アルミニウム、窒化ケイ素等の窒化物、タルク、モンモリロナイト、ベーマイト、ゼオライト、アパタイト、カオリン、ムライト、スピネル、オリビン、セリサイト、ベントナイト、マイカ等の鉱物資源由来物質又はこれらの人造物等が挙げられる。 The above filler is not particularly limited. Fillers include polyolefins such as polypropylene and polyethylene, silicon dioxide, aluminum oxide, titanium dioxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide, inorganic oxides such as aluminosilicate, magnesium hydroxide, calcium hydroxide, and water. Hydroxides such as aluminum oxide, carbonates such as calcium carbonate, sparingly soluble ion crystals such as calcium fluoride, barium fluoride, barium sulfate, nitrides such as aluminum nitride and silicon nitride, talc, montmorillonite, boehmite and zeolite. , Apatite, Kaolin, Murite, Spinel, Olivin, Sericite, Bentonite, Mica and other mineral resource-derived substances or man-made products thereof.
　正極活物質層は、Ｂ、Ｎ、Ｐ、Ｆ、Ｃｌ、Ｂｒ、Ｉ等の典型非金属元素、Ｌｉ、Ｎａ、Ｍｇ、Ａｌ、Ｓｉ、Ｋ、Ｃａ、Ｚｎ、Ｇａ、Ｇｅ、Ｓｎ、Ｓｒ、Ｂａ等の典型金属元素、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｍｏ、Ｚｒ、Ｎｂ、Ｗ等の遷移金属元素を正極活物質、導電剤、バインダー、増粘剤、フィラー以外の成分として含有してもよい。 The positive electrode active material layer is a typical non-metal element such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, Si, K, Ca, Zn, Ga, Ge, Sn, Sr, Typical metal elements such as Ba and transition metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Nb and W are used as positive electrode active materials, conductive agents, binders and thickeners. , May be contained as a component other than the filler.
＜正極の製造方法＞
　本発明の一実施形態に係る正極は、例えば以下の方法により製造することができる。すなわち、本発明の一実施形態に係る正極の製造方法は、本発明の一実施形態に係る正極活物質（Ａ）若しくは正極活物質（Ｂ）又は本発明の一実施形態に係る正極活物質の製造方法（Ａ）～（Ｃ）のいずれかで得られた正極活物質を用いて正極を作製することを備える。 <Manufacturing method of positive electrode>
The positive electrode according to the embodiment of the present invention can be manufactured by, for example, the following method. That is, the method for producing a positive electrode according to an embodiment of the present invention is the positive electrode active material (A) or the positive electrode active material (B) according to the embodiment of the present invention or the positive electrode active material according to the embodiment of the present invention. A positive electrode is produced by using the positive electrode active material obtained by any of the production methods (A) to (C).
　上記正極の作製は、例えば正極基材に直接又は中間層を介して、正極合剤ペーストを塗布し、乾燥させることにより行うことができる。上記正極合剤ペーストには、正極活物質、及び任意成分である導電剤、バインダー等、正極合剤を構成する各成分が含まれる。正極合剤ペーストには、分散媒がさらに含まれていてよい。 The positive electrode can be produced, for example, by applying the positive electrode mixture paste directly to the positive electrode substrate or via an intermediate layer and drying it. The positive electrode mixture paste contains each component constituting the positive electrode mixture, such as a positive electrode active material and optional components such as a conductive agent and a binder. The positive electrode mixture paste may further contain a dispersion medium.
　上記正極の作製において、上記正極活物質と導電剤とを混合する際に、上記正極活物質と導電剤を含む混合物をメカニカルミリング処理することが好ましい。このように、本発明の一実施形態に係る正極活物質を用いる場合に、当該正極活物質と導電剤とを含む混合物の状態でメカニカルミリング処理することにより、十分な充放電性能等を備えた非水電解質蓄電素子とすることのできる正極を確実性高く製造することができる。 In the production of the positive electrode, when the positive electrode active material and the conductive agent are mixed, it is preferable to mechanically mill the mixture containing the positive electrode active material and the conductive agent. As described above, when the positive electrode active material according to the embodiment of the present invention is used, sufficient charge / discharge performance and the like are provided by performing the mechanical milling treatment in the state of a mixture containing the positive electrode active material and the conductive agent. A positive electrode that can be used as a non-aqueous electrolyte power storage element can be manufactured with high certainty.
　ここで、メカニカルミリング処理とは、衝撃、ずり応力、摩擦等の機械的エネルギーを与えて、粉砕、混合、又は複合化する処理をいう。メカニカルミリング処理を行う装置としては、ボールミル、ビーズミル、振動ミル、ターボミル、メカノフュージョン、ディスクミルなどの粉砕・分散機が挙げられる。これらの中でもボールミルが好ましい。ボールミルに用いるボール及びミル容器としては、タングステンカーバイド（ＷＣ）製のものや、酸化ジルコニウム（ＺｒＯ２）製のものなどを好適に用いることができる。なお、ここでいうメカニカルミリング処理は、メカノケミカル反応を伴うことを要しない。このようなメカニカルミリング処理により、正極活物質と導電剤とが複合化され、電子伝導性が改善されると推測される。 Here, the mechanical milling process refers to a process of pulverizing, mixing, or compounding by applying mechanical energy such as impact, shear stress, and friction. Examples of the device for performing the mechanical milling process include crushing / dispersing machines such as ball mills, bead mills, vibration mills, turbo mills, mechanofusions, and disc mills. Of these, a ball mill is preferable. As the balls and mill containers used in the ball mill, those made of tungsten carbide (WC), those made of zirconium oxide (ZrO 2 ), and the like can be preferably used. The mechanical milling treatment referred to here does not need to be accompanied by a mechanochemical reaction. It is presumed that such mechanical milling treatment composites the positive electrode active material and the conductive agent, and improves the electron conductivity.
　ボールミルにより処理する場合、処理の際のミル回転数としては例えば１００ｒｐｍ以上１，０００ｒｐｍ以下とすることができる。また、処理時間としては、例えば０．１時間以上１００時間以下とすることができる。また、この処理は、アルゴン等の不活性ガス雰囲気下又は空気等の活性ガス雰囲気下で行うことができるが、不活性ガス雰囲気下で行うことが好ましい。 When processing with a ball mill, the mill rotation speed during processing can be, for example, 100 rpm or more and 1,000 rpm or less. The processing time can be, for example, 0.1 hour or more and 100 hours or less. Further, this treatment can be carried out in an atmosphere of an inert gas such as argon or an atmosphere of an active gas such as air, but it is preferably carried out in an atmosphere of an inert gas.
＜非水電解質蓄電素子＞
　本発明の一実施形態に係る非水電解質蓄電素子は、正極、負極及び非水電解質を有する。以下、非水電解質蓄電素子の一例として、非水電解質二次電池（以下、単に「二次電池」ともいう。）について説明する。上記正極及び負極は、通常、セパレータを介して積層又は巻回により交互に重畳された電極体を形成する。この電極体は容器に収納され、この容器内に非水電解質が充填される。上記非水電解質は、正極と負極との間に介在する。また、上記容器としては、二次電池の容器として通常用いられる公知の金属容器、樹脂容器等を用いることができる。 <Non-water electrolyte power storage element>
The non-aqueous electrolyte power storage element according to the embodiment of the present invention has a positive electrode, a negative electrode, and a non-aqueous electrolyte. Hereinafter, as an example of the non-aqueous electrolyte power storage element, a non-aqueous electrolyte secondary battery (hereinafter, also simply referred to as “secondary battery”) will be described. The positive electrode and the negative electrode usually form an electrode body that is alternately superposed by laminating or winding through a separator. The electrode body is housed in a container, and the container is filled with a non-aqueous electrolyte. The non-aqueous electrolyte is interposed between the positive electrode and the negative electrode. Further, as the container, a known metal container, resin container, or the like usually used as a container for a secondary battery can be used.
（正極）
　当該二次電池に備わる正極は、上述した本発明の一実施形態に係る正極である。 (Positive electrode)
The positive electrode provided in the secondary battery is the positive electrode according to the above-described embodiment of the present invention.
（負極）
　上記負極は、負極基材、及びこの負極基材に直接又は中間層を介して配される負極活物質層を有する。上記中間層は正極の中間層と同様の構成とすることができる。 (Negative electrode)
The negative electrode has a negative electrode base material and a negative electrode active material layer arranged directly on the negative electrode base material or via an intermediate layer. The intermediate layer may have the same structure as the intermediate layer of the positive electrode.
　上記負極基材は、正極基材と同様の構成とすることができるが、材質としては、銅、ニッケル、ステンレス鋼、ニッケルメッキ鋼等の金属又はそれらの合金が用いられ、銅又は銅合金が好ましい。つまり、負極基材としては銅箔が好ましい。銅箔としては、圧延銅箔、電解銅箔等が例示される。 The negative electrode base material may have the same configuration as the positive electrode base material, but as the material, a metal such as copper, nickel, stainless steel, nickel-plated steel or an alloy thereof is used, and copper or a copper alloy is used. preferable. That is, a copper foil is preferable as the negative electrode base material. Examples of the copper foil include rolled copper foil and electrolytic copper foil.
　負極基材の平均厚さは、２μｍ以上３５μｍ以下が好ましく、３μｍ以上３０μｍ以下がより好ましく、４μｍ以上２５μｍ以下がさらに好ましく、５μｍ以上２０μｍ以下が特に好ましい。負極基材の平均厚さを上記の範囲とすることで、負極基材の強度を高めつつ、非水電解質蓄電素子の体積当たり及び質量当たりのエネルギー密度を高めることができる。 The average thickness of the negative electrode substrate is preferably 2 μm or more and 35 μm or less, more preferably 3 μm or more and 30 μm or less, further preferably 4 μm or more and 25 μm or less, and particularly preferably 5 μm or more and 20 μm or less. By setting the average thickness of the negative electrode base material in the above range, it is possible to increase the energy density per volume and mass of the non-aqueous electrolyte power storage element while increasing the strength of the negative electrode base material.
　上記負極活物質層は、一般的に負極活物質を含むいわゆる負極合剤から形成される。また、負極活物質層を形成する負極合剤は、必要に応じて導電剤、バインダー、増粘剤、フィラー等の任意成分を含む。導電剤、バインダー、増粘剤、フィラー等の任意成分は、正極活物質層と同様のものを用いることができる。負極活物質層は、実質的に金属Ｌｉ等の負極活物質のみからなる層であってもよい。 The negative electrode active material layer is generally formed of a so-called negative electrode mixture containing a negative electrode active material. Further, the negative electrode mixture forming the negative electrode active material layer contains optional components such as a conductive agent, a binder, a thickener, and a filler, if necessary. As any component such as a conductive agent, a binder, a thickener, and a filler, the same one as that of the positive electrode active material layer can be used. The negative electrode active material layer may be a layer substantially composed of only a negative electrode active material such as metallic Li.
　負極活物質層は、Ｂ、Ｎ、Ｐ、Ｆ、Ｃｌ、Ｂｒ、Ｉ等の典型非金属元素、Ｌｉ、Ｎａ、Ｍｇ、Ａｌ、Ｋ、Ｃａ、Ｚｎ、Ｇａ、Ｇｅ、Ｓｎ、Ｓｒ、Ｂａ等の典型金属元素、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｍｏ、Ｚｒ、Ｔａ、Ｈｆ、Ｎｂ、Ｗ等の遷移金属元素を負極活物質、導電剤、バインダー、増粘剤、フィラー以外の成分として含有してもよい。 The negative electrode active material layer includes typical non-metal elements such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, K, Ca, Zn, Ga, Ge, Sn, Sr, Ba and the like. Typical metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Ta, Hf, Nb, W, etc. It may be contained as a component other than the thickener and the filler.
　負極活物質としては、公知の負極活物質の中から適宜選択できる。例えばリチウムイオン二次電池用の負極活物質としては、通常、リチウムイオンを吸蔵及び放出することができる材料が用いられる。負極活物質としては、例えば、金属Ｌｉ；Ｓｉ、Ｓｎ等の金属又は半金属；Ｓｉ酸化物、Ｔｉ酸化物、Ｓｎ酸化物等の金属酸化物又は半金属酸化物；Ｌｉ４Ｔｉ５Ｏ１２、ＬｉＴｉＯ２、ＴｉＮｂ２Ｏ７等のチタン含有酸化物；ポリリン酸化合物；炭化ケイ素；黒鉛（グラファイト）、非黒鉛質炭素（易黒鉛化性炭素又は難黒鉛化性炭素）等の炭素材料等が挙げられる。これらの材料の中でも、黒鉛及び非黒鉛質炭素が好ましい。負極活物質層においては、これら材料の１種を単独で用いてもよく、２種以上を混合して用いてもよい。 The negative electrode active material can be appropriately selected from known negative electrode active materials. For example, as a negative electrode active material for a lithium ion secondary battery, a material capable of occluding and releasing lithium ions is usually used. Examples of the negative electrode active material include metal Li; metal or semi-metal such as Si and Sn; metal oxide or semi-metal oxide such as Si oxide, Ti oxide and Sn oxide; Li 4 Ti 5 O 12 ; Titanium-containing oxides such as LiTIO 2 and TiNb 2O 7 ; polyphosphate compounds; silicon carbide; carbon materials such as graphite (graphite) and non-graphitric carbon (easy graphitable carbon or non-graphitizable carbon) can be mentioned. Be done. Among these materials, graphite and non-graphitic carbon are preferable. In the negative electrode active material layer, one of these materials may be used alone, or two or more of them may be mixed and used.
　「黒鉛」とは、充放電前又は放電状態において、エックス線回折法により決定される（００２）面の平均格子面間隔（ｄ００２）が０．３３ｎｍ以上０．３４ｎｍ未満の炭素材料をいう。黒鉛としては、天然黒鉛、人造黒鉛が挙げられる。安定した物性の材料を入手できるという観点で、人造黒鉛が好ましい。 “Graphite” refers to a carbon material having an average lattice spacing (d 002 ) of (002) planes determined by X-ray diffraction method before charging / discharging or in a discharged state of 0.33 nm or more and less than 0.34 nm. Examples of graphite include natural graphite and artificial graphite. Artificial graphite is preferable from the viewpoint that a material having stable physical properties can be obtained.
　「非黒鉛質炭素」とは、充放電前又は放電状態においてエックス線回折法により決定される（００２）面の平均格子面間隔（ｄ００２）が０．３４ｎｍ以上０．４２ｎｍ以下の炭素材料をいう。非黒鉛質炭素としては、難黒鉛化性炭素や、易黒鉛化性炭素が挙げられる。非黒鉛質炭素としては、例えば、樹脂由来の材料、石油ピッチまたは石油ピッチ由来の材料、石油コークスまたは石油コークス由来の材料、植物由来の材料、アルコール由来の材料等が挙げられる。 "Non-graphitic carbon" refers to a carbon material having an average lattice spacing (d 002 ) of the (002) plane determined by the X-ray diffraction method before charging / discharging or in a discharged state of 0.34 nm or more and 0.42 nm or less. .. Examples of non-graphitizable carbon include non-graphitizable carbon and easily graphitizable carbon. Examples of the non-planar carbon include a resin-derived material, a petroleum pitch or a petroleum pitch-derived material, a petroleum coke or a petroleum coke-derived material, a plant-derived material, an alcohol-derived material, and the like.
　ここで、炭素材料の「放電状態」とは、負極活物質として炭素材料を含む負極を作用極として、金属Ｌｉを対極として用いた単極電池において、開回路電圧が０．７Ｖ以上である状態をいう。開回路状態での金属Ｌｉ対極の電位は、Ｌｉの酸化還元電位とほぼ等しいため、上記単極電池における開回路電圧は、Ｌｉの酸化還元電位に対する炭素材料を含む負極の電位とほぼ同等である。つまり、上記単極電池における開回路電圧が０．７Ｖ以上であることは、負極活物質である炭素材料から、充放電に伴い吸蔵放出可能なリチウムイオンが十分に放出されていることを意味する。 Here, the "discharged state" of the carbon material is a state in which the open circuit voltage is 0.7 V or more in a unipolar battery using a negative electrode containing a carbon material as a negative electrode active material as a working electrode and a metal Li as a counter electrode. To say. Since the potential of the metal Li counter electrode in the open circuit state is substantially equal to the redox potential of Li, the open circuit voltage in the single pole battery is substantially equal to the potential of the negative electrode containing the carbon material with respect to the redox potential of Li. .. That is, the fact that the open circuit voltage in the single-pole battery is 0.7 V or more means that the carbon material, which is the negative electrode active material, sufficiently releases lithium ions that can be occluded and discharged by charging and discharging. ..
　「難黒鉛化性炭素」とは、上記ｄ００２が０．３６ｎｍ以上０．４２ｎｍ以下の炭素材料をいう。 The “non-graphitizable carbon” refers to a carbon material having d 002 of 0.36 nm or more and 0.42 nm or less.
　「易黒鉛化性炭素」とは、上記ｄ００２が０．３４ｎｍ以上０．３６ｎｍ未満の炭素材料をいう。 The “graphitizable carbon” refers to a carbon material having d 002 of 0.34 nm or more and less than 0.36 nm.
　負極活物質の形態が粒子（粉体）の場合、負極活物質の平均粒径は、例えば、１ｎｍ以上１００μｍ以下とすることができる。負極活物質が例えば炭素材料である場合、その平均粒径は１μｍ以上１００μｍ以下が好ましい場合がある。負極活物質が、金属、半金属、金属酸化物、半金属酸化物、チタン含有酸化物、ポリリン酸化合物等である場合、その平均粒径は、１ｎｍ以上１μｍ以下が好ましい場合がある。負極活物質の平均粒径を上記下限以上とすることで、負極活物質の製造又は取り扱いが容易になる。負極活物質の平均粒径を上記上限以下とすることで、活物質層の電子伝導性が向上する。粉体を所定の粒径で得るためには粉砕機や分級機等が用いられる。また、負極活物質が金属Ｌｉの場合、その形態は箔状又は板状であってもよい。 When the form of the negative electrode active material is particles (powder), the average particle size of the negative electrode active material can be, for example, 1 nm or more and 100 μm or less. When the negative electrode active material is, for example, a carbon material, the average particle size thereof may be preferably 1 μm or more and 100 μm or less. When the negative electrode active material is a metal, a semi-metal, a metal oxide, a semi-metal oxide, a titanium-containing oxide, a polyphosphate compound or the like, the average particle size thereof may be preferably 1 nm or more and 1 μm or less. By setting the average particle size of the negative electrode active material to be equal to or higher than the above lower limit, the production or handling of the negative electrode active material becomes easy. By setting the average particle size of the negative electrode active material to the above upper limit or less, the electron conductivity of the active material layer is improved. A crusher, a classifier, or the like is used to obtain a powder having a predetermined particle size. When the negative electrode active material is metallic Li, the form may be foil-shaped or plate-shaped.
　負極活物質層における負極活物質の含有量は、例えば負極活物質層が負極合剤から形成されている場合、６０質量％以上９９質量％以下が好ましく、９０質量％以上９８質量％以下がより好ましい。負極活物質の含有量を上記の範囲とすることで、負極活物質層の高エネルギー密度化と製造性を両立できる。負極活物質が金属Ｌｉである場合、負極活物質層における負極活物質の含有量は９９質量％以上であってもよく、１００質量％であってもよい。 The content of the negative electrode active material in the negative electrode active material layer is preferably 60% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 98% by mass or less, for example, when the negative electrode active material layer is formed of a negative electrode mixture. preferable. By setting the content of the negative electrode active material within the above range, it is possible to achieve both high energy density and manufacturability of the negative electrode active material layer. When the negative electrode active material is metallic Li, the content of the negative electrode active material in the negative electrode active material layer may be 99% by mass or more, or may be 100% by mass.
（セパレータ）
　セパレータは、公知のセパレータの中から適宜選択できる。セパレータとして、例えば、基材層のみからなるセパレータ、基材層の一方の面又は双方の面に耐熱粒子とバインダーとを含む耐熱層が形成されたセパレータ等を使用することができる。セパレータの基材層としては、例えば、織布、不織布、多孔質樹脂フィルム等が挙げられる。これらの中でも、強度の観点から多孔質樹脂フィルムが好ましく、非水電解質の保液性の観点から不織布が好ましい。セパレータの基材層の材料としては、シャットダウン機能の観点から例えばポリエチレン、ポリプロピレン等のポリオレフィンが好ましく、耐酸化分解性の観点から例えばポリイミドやアラミド等が好ましい。セパレータの基材層として、これらの樹脂を複合した材料を用いてもよい。 (Separator)
The separator can be appropriately selected from known separators. As the separator, for example, a separator composed of only a base material layer, a separator having a heat-resistant layer containing heat-resistant particles and a binder formed on one surface or both surfaces of the base material layer can be used. Examples of the base material layer of the separator include woven fabrics, non-woven fabrics, and porous resin films. Among these, a porous resin film is preferable from the viewpoint of strength, and a non-woven fabric is preferable from the viewpoint of liquid retention of a non-aqueous electrolyte. As the material of the base material layer of the separator, polyolefins such as polyethylene and polypropylene are preferable from the viewpoint of shutdown function, and polyimide and aramid are preferable from the viewpoint of oxidative decomposition resistance. As the base material layer of the separator, a material in which these resins are combined may be used.
　耐熱層に含まれる耐熱粒子は、大気下で室温から５００℃まで加熱したときの質量減少が５％以下であるものが好ましく、大気下で室温から８００℃まで加熱したときの質量減少が５％以下であるものがさらに好ましい。上記の質量減少が所定値以下である材料として無機化合物が挙げられる。無機化合物として、例えば、酸化鉄、酸化ケイ素、酸化アルミニウム、酸化チタン、酸化ジルコニウム、酸化カルシウム、酸化ストロンチウム、酸化バリウム、酸化マグネシウム、アルミノケイ酸塩等の酸化物；水酸化マグネシウム、水酸化カルシウム、水酸化アルミニウム等の水酸化物；窒化アルミニウム、窒化ケイ素等の窒化物；炭酸カルシウム等の炭酸塩；硫酸バリウム等の硫酸塩；フッ化カルシウム、フッ化バリウム、チタン酸バリウム等の難溶性のイオン結晶；シリコン、ダイヤモンド等の共有結合性結晶；タルク、モンモリロナイト、ベーマイト、ゼオライト、アパタイト、カオリン、ムライト、スピネル、オリビン、セリサイト、ベントナイト、マイカ等の鉱物資源由来物質又はこれらの人造物等が挙げられる。無機化合物として、これらの物質の単体又は複合体を単独で用いてもよく、２種以上を混合して用いてもよい。これらの無機化合物の中でも、蓄電素子の安全性の観点から、酸化ケイ素、酸化アルミニウム、又はアルミノケイ酸塩が好ましい。 The heat-resistant particles contained in the heat-resistant layer preferably have a mass loss of 5% or less when heated from room temperature to 500 ° C. in the atmosphere, and a mass loss of 5% when heated from room temperature to 800 ° C. in the atmosphere. The following are more preferable. Examples of the material whose mass reduction is equal to or less than a predetermined value include inorganic compounds. Examples of the inorganic compound include oxides such as iron oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide and aluminosilicate; magnesium hydroxide, calcium hydroxide and water. Hydroxides such as aluminum oxide; Nitridees such as aluminum nitride and silicon nitride; Carbonates such as calcium carbonate; Sulfates such as barium sulfate; Slowly soluble ion crystals such as calcium fluoride, barium fluoride and barium titanate Covalently bonded crystals such as silicon and diamond; talc, montmorillonite, boehmite, zeolite, apatite, kaolin, mulite, spinel, olivine, sericite, bentonite, mica and other mineral resource-derived substances or man-made products thereof. .. As the inorganic compound, a simple substance or a complex of these substances may be used alone, or two or more kinds thereof may be mixed and used. Among these inorganic compounds, silicon oxide, aluminum oxide, or aluminosilicate is preferable from the viewpoint of safety of the power storage device.
　セパレータの空孔率は、強度の観点から８０体積％以下が好ましく、放電性能の観点から２０体積％以上が好ましい。ここで、「空孔率」とは、体積基準の値であり、水銀ポロシメータでの測定値を意味する。 The porosity of the separator is preferably 80% by volume or less from the viewpoint of strength, and preferably 20% by volume or more from the viewpoint of discharge performance. Here, the "porosity" is a value based on volume, and means a value measured by a mercury porosity meter.
　セパレータとして、ポリマーと非水電解質とで構成されるポリマーゲルを用いてもよい。ポリマーとして、例えば、ポリアクリロニトリル、ポリエチレンオキシド、ポリプロピレンオキシド、ポリメチルメタアクリレート、ポリビニルアセテート、ポリビニルピロリドン、ポリフッ化ビニリデン等が挙げられる。ポリマーゲルを用いると、漏液を抑制する効果がある。セパレータとして、上述したような多孔質樹脂フィルム又は不織布等とポリマーゲルを併用してもよい。 As the separator, a polymer gel composed of a polymer and a non-aqueous electrolyte may be used. Examples of the polymer include polyacrylonitrile, polyethylene oxide, polypropylene oxide, polymethyl methacrylate, polyvinyl acetate, polyvinylpyrrolidone, polyvinylidene fluoride and the like. The use of polymer gel has the effect of suppressing liquid leakage. As the separator, a polymer gel may be used in combination with a porous resin film or a non-woven fabric as described above.
（非水電解質）
　非水電解質としては、公知の非水電解質の中から適宜選択できる。非水電解質には、非水電解液を用いてもよい。非水電解液は、非水溶媒と、この非水溶媒に溶解されている電解質塩とを含む。 (Non-water electrolyte)
As the non-aqueous electrolyte, a known non-aqueous electrolyte can be appropriately selected. A non-aqueous electrolyte solution may be used as the non-aqueous electrolyte. The non-aqueous electrolyte solution contains a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
　非水溶媒としては、公知の非水溶媒の中から適宜選択できる。非水溶媒としては、環状カーボネート、鎖状カーボネート、カルボン酸エステル、リン酸エステル、スルホン酸エステル、エーテル、アミド、ニトリル等が挙げられる。非水溶媒として、これらの化合物に含まれる水素原子の一部がハロゲンに置換されたものを用いてもよい。 The non-aqueous solvent can be appropriately selected from known non-aqueous solvents. Examples of the non-aqueous solvent include cyclic carbonates, chain carbonates, carboxylic acid esters, phosphoric acid esters, sulfonic acid esters, ethers, amides, nitriles and the like. As the non-aqueous solvent, a solvent in which some of the hydrogen atoms contained in these compounds are replaced with halogen may be used.
　環状カーボネートとしては、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、ビニレンカーボネート（ＶＣ）、ビニルエチレンカーボネート（ＶＥＣ）、クロロエチレンカーボネート、フルオロエチレンカーボネート（ＦＥＣ）、ジフルオロエチレンカーボネート（ＤＦＥＣ）、スチレンカーボネート、１－フェニルビニレンカーボネート、１，２－ジフェニルビニレンカーボネート等が挙げられる。これらの中でもＥＣが好ましい。 Examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), vinyl ethylene carbonate (VEC), chloroethylene carbonate, fluoroethylene carbonate (FEC), and difluoroethylene carbonate. (DFEC), styrene carbonate, 1-phenylvinylene carbonate, 1,2-diphenylvinylene carbonate and the like can be mentioned. Among these, EC is preferable.
　鎖状カーボネートとしては、ジエチルカーボネート（ＤＥＣ）、ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）、ジフェニルカーボネート、トリフルオロエチルメチルカーボネート、ビス（トリフルオロエチル）カーボネート等が挙げられる。これらの中でもＤＭＣ及びＥＭＣが好ましい。 Examples of the chain carbonate include diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), diphenyl carbonate, trifluoroethylmethyl carbonate, bis (trifluoroethyl) carbonate and the like. Among these, DMC and EMC are preferable.
　非水溶媒として、環状カーボネート及び鎖状カーボネートの少なくとも一方を用いることが好ましく、環状カーボネートと鎖状カーボネートとを併用することがより好ましい。環状カーボネートを用いることで、電解質塩の解離を促進して非水電解液のイオン伝導度を向上させることができる。鎖状カーボネートを用いることで、非水電解液の粘度を低く抑えることができる。環状カーボネートと鎖状カーボネートとを併用する場合、環状カーボネートと鎖状カーボネートとの体積比率（環状カーボネート：鎖状カーボネート）としては、例えば、５：９５から５０：５０の範囲とすることが好ましい。 It is preferable to use at least one of the cyclic carbonate and the chain carbonate as the non-aqueous solvent, and it is more preferable to use the cyclic carbonate and the chain carbonate in combination. By using the cyclic carbonate, the dissociation of the electrolyte salt can be promoted and the ionic conductivity of the non-aqueous electrolyte solution can be improved. By using the chain carbonate, the viscosity of the non-aqueous electrolytic solution can be kept low. When the cyclic carbonate and the chain carbonate are used in combination, the volume ratio of the cyclic carbonate to the chain carbonate (cyclic carbonate: chain carbonate) is preferably in the range of, for example, 5:95 to 50:50.
　電解質塩としては、公知の電解質塩から適宜選択できる。電解質塩としては、リチウム塩、ナトリウム塩、カリウム塩、マグネシウム塩、オニウム塩等が挙げられる。これらの中でもリチウム塩が好ましい。 The electrolyte salt can be appropriately selected from known electrolyte salts. Examples of the electrolyte salt include lithium salt, sodium salt, potassium salt, magnesium salt, onium salt and the like. Of these, lithium salts are preferred.
　リチウム塩としては、ＬｉＰＦ６、ＬｉＰＯ２Ｆ２、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＮ（ＳＯ２Ｆ）２等の無機リチウム塩、ＬｉＳＯ３ＣＦ３、ＬｉＮ（ＳＯ２ＣＦ３）２、ＬｉＮ（ＳＯ２Ｃ２Ｆ５）２、ＬｉＮ（ＳＯ２ＣＦ３）（ＳＯ２Ｃ４Ｆ９）、ＬｉＣ（ＳＯ２ＣＦ３）３、ＬｉＣ（ＳＯ２Ｃ２Ｆ５）３等のハロゲン化炭化水素基を有するリチウム塩等が挙げられる。これらの中でも、無機リチウム塩が好ましく、ＬｉＰＦ６がより好ましい。 Lithium salts include inorganic lithium salts such as LiPF 6 , LiPO 2 F 2 , LiBF 4 , LiClO 4 , LiN (SO 2 F) 2 , LiSO 3 CF 3 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 ). C 2 F 5 ) 2 , LiN (SO 2 CF 3 ) (SO 2 C 4 F 9 ), LiC (SO 2 CF 3 ) 3 , LiC (SO 2 C 2 F 5 ) 3 and other halogenated hydrocarbon groups Examples thereof include lithium salts having. Among these, an inorganic lithium salt is preferable, and LiPF 6 is more preferable.
　非水電解液における電解質塩の含有量は、０．１ｍｏｌ／ｄｍ３以上２．５ｍｏｌ／ｄｍ３以下であると好ましく、０．３ｍｏｌ／ｄｍ３以上２．０ｍｏｌ／ｄｍ３以下であるとより好ましく、０．５ｍｏｌ／ｄｍ３以上１．７ｍｏｌ／ｄｍ３以下であるとさらに好ましく、０．７ｍｏｌ／ｄｍ３以上１．５ｍｏｌ／ｄｍ３以下であると特に好ましい。電解質塩の含有量を上記の範囲とすることで、非水電解液のイオン伝導度を高めることができる。 The content of the electrolyte salt in the non-aqueous electrolyte solution is preferably 0.1 mol / dm 3 or more and 2.5 mol / dm 3 or less, and more preferably 0.3 mol / dm 3 or more and 2.0 mol / dm 3 or less. , 0.5 mol / dm 3 or more and 1.7 mol / dm 3 or less is more preferable, and 0.7 mol / dm 3 or more and 1.5 mol / dm 3 or less is particularly preferable. By setting the content of the electrolyte salt in the above range, the ionic conductivity of the non-aqueous electrolyte solution can be increased.
　非水電解液は、添加剤を含んでもよい。添加剤としては、例えばビフェニル、アルキルビフェニル、ターフェニル、ターフェニルの部分水素化体、シクロヘキシルベンゼン、ｔ－ブチルベンゼン、ｔ－アミルベンゼン、ジフェニルエーテル、ジベンゾフラン等の芳香族化合物；２－フルオロビフェニル、ｏ－シクロヘキシルフルオロベンゼン、ｐ－シクロヘキシルフルオロベンゼン等の上記芳香族化合物の部分ハロゲン化物；２，４－ジフルオロアニソール、２，５－ジフルオロアニソール、２，６－ジフルオロアニソール、３，５－ジフルオロアニソール等のハロゲン化アニソール化合物；無水コハク酸、無水グルタル酸、無水マレイン酸、無水シトラコン酸、無水グルタコン酸、無水イタコン酸、シクロヘキサンジカルボン酸無水物；亜硫酸エチレン、亜硫酸プロピレン、亜硫酸ジメチル、硫酸ジメチル、硫酸エチレン、スルホラン、ジメチルスルホン、ジエチルスルホン、ジメチルスルホキシド、ジエチルスルホキシド、テトラメチレンスルホキシド、ジフェニルスルフィド、４，４’－ビス（２，２－ジオキソ－１，３，２－ジオキサチオラン）、４－メチルスルホニルオキシメチル－２，２－ジオキソ－１，３，２－ジオキサチオラン、チオアニソール、ジフェニルジスルフィド、ジピリジニウムジスルフィド、パーフルオロオクタン、ホウ酸トリストリメチルシリル、リン酸トリストリメチルシリル、チタン酸テトラキストリメチルシリル等が挙げられる。これら添加剤は、１種を単独で用いてもよく、２種以上を混合して用いてもよい。 The non-aqueous electrolytic solution may contain an additive. Examples of the additive include aromatic compounds such as biphenyl, alkyl biphenyl, terphenyl, and partially hydrides of turphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, and dibenzofuran; 2-fluorobiphenyl, o. -Partial halides of the above aromatic compounds such as cyclohexylfluorobenzene and p-cyclohexylfluorobenzene; Halogenated anisole compounds; succinic anhydride, glutaric anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, cyclohexanedicarboxylic acid anhydride; ethylene sulfone, propylene sulfite, dimethyl sulfite, dimethyl sulfate, ethylene sulfate, Sulfone, dimethyl sulfone, diethyl sulfone, dimethyl sulfoxide, diethyl sulfoxide, tetramethylene sulfoxide, diphenyl sulfide, 4,4'-bis (2,2-dioxo-1,3,2-dioxathiolane), 4-methylsulfonyloxymethyl- Examples thereof include 2,2-dioxo-1,3,2-dioxathiolane, thioanisole, diphenyldisulfide, dipyridinium disulfide, perfluorooctane, tristrimethylsilyl borate, tristrimethylsilyl phosphate, tetrakistrimethylsilyl titanate and the like. These additives may be used alone or in combination of two or more.
　非水電解液に含まれる添加剤の含有量は、非水電解液全体の質量に対して０．０１質量％以上１０質量％以下が好ましく、０．１質量％以上７質量％以下がより好ましく、０．２質量％以上５質量％以下がさらに好ましく、０．３質量％以上３質量％以下が特に好ましい。添加剤の含有量を上記の範囲とすることで、高温保存後の容量維持性能又は充放電サイクル性能を向上させたり、安全性をより向上させたりすることができる。 The content of the additive contained in the non-aqueous electrolytic solution is preferably 0.01% by mass or more and 10% by mass or less, and more preferably 0.1% by mass or more and 7% by mass or less with respect to the total mass of the non-aqueous electrolytic solution. , 0.2% by mass or more and 5% by mass or less is more preferable, and 0.3% by mass or more and 3% by mass or less is particularly preferable. By setting the content of the additive in the above range, it is possible to improve the capacity maintenance performance or charge / discharge cycle performance after high temperature storage, and further improve the safety.
　非水電解質には、固体電解質を用いてもよく、非水電解液と固体電解質とを併用してもよい。 As the non-aqueous electrolyte, a solid electrolyte may be used, or a non-aqueous electrolyte solution and a solid electrolyte may be used in combination.
　固体電解質としては、リチウムイオン伝導性を有し、常温（例えば１５℃から２５℃）において固体である任意の材料から選択できる。固体電解質としては、例えば、硫化物固体電解質、酸化物固体電解質、酸窒化物固体電解質、ポリマー固体電解質等が挙げられる。 The solid electrolyte can be selected from any material having lithium ion conductivity and being solid at room temperature (for example, 15 ° C to 25 ° C). Examples of the solid electrolyte include a sulfide solid electrolyte, an oxide solid electrolyte, an oxynitride solid electrolyte, a polymer solid electrolyte and the like.
　硫化物固体電解質としては、リチウムイオン二次電池の場合、例えば、Ｌｉ２Ｓ－Ｐ２Ｓ５、ＬｉＩ－Ｌｉ２Ｓ－Ｐ２Ｓ５、Ｌｉ１０ＧｅＰ２Ｓ１２等が挙げられる。 Examples of the lithium ion secondary battery include Li 2 SP 2 S 5 , Li I-Li 2 SP 2 S 5 , Li 10 GeP 2 S 12 , and the like as the sulfide solid electrolyte.
（充電電気量）
　本発明の一実施形態に係る非水電解質蓄電素子は、正極に本発明の一実施形態に係る正極活物質が用いられているため、充電電気量が比較的大きい場合もクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されやすい。従って、当該非水電解質蓄電素子は、充電電気量が大きい使用形態に好適に用いることができる。例えば、当該非水電解質蓄電素子においては、通常使用時の正極活物質の質量あたりの充電電気量が３００ｍＡｈ／ｇ以上６００ｍＡｈ／ｇ以下であることが好ましく、４００ｍＡｈ／ｇ以上５００ｍＡｈ／ｇ以下であることがより好ましい。上記のように本発明の一実施形態に係る非水電解質蓄電素子は充電電気量が比較的大きい場合もクーロン効率が高いため、充電電気量を上記下限以上とすることで、実効電気量を大きくすることができる。一方、充電電気量を上記上限以下とすることで、充放電を繰り返した場合のクーロン効率がより維持されやすくなる。なお、充電電気量は、以下の方法で測定される値とする。まず、蓄電素子を０．０５Ｃの電流で通常使用時の下限電圧まで定電流放電する。３０分の休止後、蓄電素子を０．０５Ｃの電流で通常使用時の充電終止電圧となるまで定電流充電し、満充電状態とする。このとき充電される電気量を充電電気量とする。 (Charging electricity amount)
In the non-aqueous electrolyte power storage element according to the embodiment of the present invention, since the positive electrode active material according to the embodiment of the present invention is used for the positive electrode, the coulomb efficiency is high even when the amount of charging electricity is relatively large. This high Coulomb efficiency is likely to be maintained even after repeated discharges. Therefore, the non-aqueous electrolyte power storage element can be suitably used in a usage mode in which the amount of charging electricity is large. For example, in the non-aqueous electrolyte power storage element, the amount of charging electricity per mass of the positive electrode active material in normal use is preferably 300 mAh / g or more and 600 mAh / g or less, and 400 mAh / g or more and 500 mAh / g or less. Is more preferable. As described above, the non-aqueous electrolyte power storage element according to the embodiment of the present invention has high Coulomb efficiency even when the charging electricity amount is relatively large. Therefore, by setting the charging electricity amount to the above lower limit or more, the effective electricity amount is increased. can do. On the other hand, by setting the amount of charging electricity to be equal to or less than the above upper limit, it becomes easier to maintain the Coulomb efficiency when charging and discharging are repeated. The amount of charging electricity is a value measured by the following method. First, the power storage element is constantly discharged to the lower limit voltage during normal use with a current of 0.05 C. After a 30-minute pause, the power storage element is charged with a current of 0.05 C at a constant current until it reaches the end-of-charge voltage during normal use, and is in a fully charged state. The amount of electricity charged at this time is defined as the amount of electricity charged.
　本実施形態の非水電解質蓄電素子の形状については特に限定されるものではなく、例えば、円筒型電池、角型電池、扁平型電池、コイン型電池、ボタン型電池等が挙げられる。 The shape of the non-aqueous electrolyte power storage element of the present embodiment is not particularly limited, and examples thereof include a cylindrical battery, a square battery, a flat battery, a coin battery, and a button battery.
　図１に角型電池の一例としての非水電解質蓄電素子１を示す。なお、同図は、容器内部を透視した図としている。セパレータを挟んで巻回された正極及び負極を有する電極体２が角型の容器３に収納される。正極は正極リード４１を介して正極端子４と電気的に接続されている。負極は負極リード５１を介して負極端子５と電気的に接続されている。 FIG. 1 shows a non-aqueous electrolyte power storage element 1 as an example of a square battery. The figure is a perspective view of the inside of the container. The electrode body 2 having the positive electrode and the negative electrode wound around the separator is housed in the square container 3. The positive electrode is electrically connected to the positive electrode terminal 4 via the positive electrode lead 41. The negative electrode is electrically connected to the negative electrode terminal 5 via the negative electrode lead 51.
＜蓄電装置の構成＞
　本発明の一実施形態に係る蓄電装置は、非水電解質蓄電素子を複数個備え、且つ本発明の一実施形態に係る非水電解質蓄電素子を一以上備える。本実施形態の非水電解質蓄電素子は、電気自動車（ＥＶ）、ハイブリッド自動車（ＨＥＶ）、プラグインハイブリッド自動車（ＰＨＥＶ）等の自動車用電源、パーソナルコンピュータ、通信端末等の電子機器用電源、又は電力貯蔵用電源等に、複数の非水電解質蓄電素子１を集合して構成した蓄電ユニット（バッテリーモジュール）をさらに集合した蓄電装置として搭載することができる。この場合、蓄電装置に含まれる少なくとも一つの非水電解質蓄電素子に対して、本発明の一実施形態に係る技術が適用されていればよい。 <Configuration of power storage device>
The power storage device according to one embodiment of the present invention includes a plurality of non-aqueous electrolyte power storage elements, and includes one or more non-water electrolyte power storage elements according to one embodiment of the present invention. The non-aqueous electrolyte power storage element of the present embodiment is a power source for automobiles such as an electric vehicle (EV), a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV), a power source for electronic devices such as a personal computer and a communication terminal, or a power source. A power storage unit (battery module) composed of a plurality of non-aqueous electrolyte power storage elements 1 can be mounted on a storage power source or the like as a power storage device further assembled. In this case, the technique according to the embodiment of the present invention may be applied to at least one non-aqueous electrolyte power storage element included in the power storage device.
　図２に、電気的に接続された二以上の非水電解質蓄電素子１が集合した蓄電ユニット２０をさらに集合した蓄電装置３０の一例を示す。蓄電装置３０は、二以上の非水電解質蓄電素子１を電気的に接続するバスバ（図示せず）、二以上の蓄電ユニット２０を電気的に接続するバスバ（図示せず）等を備えていてもよい。蓄電ユニット２０又は蓄電装置３０は、一以上の非水電解質蓄電素子の状態を監視する状態監視装置（図示せず）を備えていてもよい。 FIG. 2 shows an example of a power storage device 30 in which a power storage unit 20 in which two or more electrically connected non-aqueous electrolyte power storage elements 1 are assembled is further assembled. The power storage device 30 includes a bus bar (not shown) for electrically connecting two or more non-aqueous electrolyte power storage elements 1, a bus bar (not shown) for electrically connecting two or more power storage units 20 and the like. May be good. The power storage unit 20 or the power storage device 30 may include a condition monitoring device (not shown) for monitoring the state of one or more non-aqueous electrolyte power storage elements.
＜非水電解質蓄電素子の製造方法＞
　本発明の一実施形態に係る非水電解質蓄電素子は、本発明の一実施形態に係る正極を用いることにより製造することができる。本発明の一実施形態に係る非水電解質蓄電素子の製造方法は、本発明の一実施形態に係る正極の製造方法を備える。 <Manufacturing method of non-aqueous electrolyte power storage element>
The non-aqueous electrolyte power storage device according to the embodiment of the present invention can be manufactured by using the positive electrode according to the embodiment of the present invention. The method for manufacturing a non-aqueous electrolyte power storage element according to an embodiment of the present invention includes a method for manufacturing a positive electrode according to an embodiment of the present invention.
　例えば、当該非水電解質蓄電素子の製造方法は、上述した正極を作製すること、負極を作製すること、非水電解質を調製すること、セパレータを介して正極及び負極を積層又は巻回することにより交互に重畳された電極体を形成すること、正極及び負極（電極体）を容器に収容すること、並びに上記容器に上記非水電解質を注入することを備える。注入後、注入口を封止することにより当該非水電解質蓄電素子を得ることができる。 For example, the method for manufacturing the non-aqueous electrolyte power storage element includes producing the above-mentioned positive electrode, producing a negative electrode, preparing a non-aqueous electrolyte, and laminating or winding a positive electrode and a negative electrode via a separator. It comprises forming the electrode bodies alternately superimposed, accommodating the positive electrode body and the negative electrode body (electrode body) in a container, and injecting the non-aqueous electrolyte into the container. After the injection, the non-aqueous electrolyte power storage element can be obtained by sealing the injection port.
＜その他の実施形態＞
　本発明は、上記実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加えてもよい。例えば、ある実施形態の構成に他の実施形態の構成を追加することができ、また、ある実施形態の構成の一部を他の実施形態の構成又は周知技術に置き換えることができる。さらに、ある実施形態の構成の一部を削除することができる。また、ある実施形態の構成に対して周知技術を付加することができる。 <Other embodiments>
The present invention is not limited to the above embodiment, and various modifications may be made without departing from the gist of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment or a well-known technique. In addition, some of the configurations of certain embodiments can be deleted. Further, a well-known technique can be added to the configuration of a certain embodiment.
　上記実施形態では、置換元素の選択方法において、（１）候補酸化物の選択、（２）原子配列の決定、及び（３）条件Ａ及び条件Ｂの検討の手順をとっている。ここで、「（２）の原子配列の決定」において、上述した遺伝的アルゴリズムを組み合わせた第一原理計算以外の方法によって行ってもよい。また、「（３）条件Ａ及び条件Ｂの検討」において、構造安定性の高い上位５つの構造に基づいて検討を行わなくてもよい。その他、置換元素の選択方法においての計算条件等は適宜変更して行ってもよい。 In the above embodiment, in the method of selecting a substituent, (1) selection of a candidate oxide, (2) determination of an atomic arrangement, and (3) examination of conditions A and B are taken. Here, in "determination of atomic arrangement in (2)", a method other than the first-principles calculation combined with the above-mentioned genetic algorithm may be performed. Further, in "(3) Examination of condition A and condition B", it is not necessary to carry out the examination based on the top five structures having high structural stability. In addition, the calculation conditions and the like in the method of selecting the substituent may be changed as appropriate.
　上記実施形態では、非水電解質蓄電素子が充放電可能な非水電解質二次電池（例えばリチウムイオン二次電池）として用いられる場合について説明したが、非水電解質蓄電素子の種類、形状、寸法、容量等は任意である。本発明の非水電解液蓄電素子は、種々の非水電解質二次電池、電気二重層キャパシタ又はリチウムイオンキャパシタ等のキャパシタにも適用できる。 In the above embodiment, the case where the non-aqueous electrolyte storage element is used as a chargeable / dischargeable non-aqueous electrolyte secondary battery (for example, a lithium ion secondary battery) has been described. The capacity etc. are arbitrary. The non-aqueous electrolyte storage element of the present invention can also be applied to capacitors such as various non-aqueous electrolyte secondary batteries, electric double layer capacitors, and lithium ion capacitors.
　以下、実施例によって本発明をさらに具体的に説明するが、本発明は以下の実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.
［実施例１］置換元素の選択
　候補酸化物として、表２に記載の各組成を有し、蛍石型の結晶構造を有する酸化物Ｎｏ．１からＮｏ．２１を選択し、計算を行った。
　上記各酸化物に対して、本発明の一実施形態に係る「置換元素の選択方法」として記載の「（２）原子配列の決定」及び「（３）条件Ａ及び条件Ｂの検討」の内容に沿った、第一原理計算を用いた方法により、条件Ａ及び条件Ｂを満たすか判断した。計算ソフトウェアは、Ｖｉｅｎｎａ　Ａｂ－ｉｎｉｔｉｏ　Ｓｉｍｕｌａｔｉｏｎ　Ｐａｃｋａｇｅ（ＶＡＳＰ）を用いた。また、本発明の一実施形態に係る「置換元素の選択方法」において上記した条件Ａ及び条件Ｂにおける所定の充電状態は４００ｍＡｈ／ｇまで充電した状態とし、条件Ａにおける存在比の所定値は０．５３とし、条件Ｂにおける存在比の所定値は０．１１とした。すなわち、本発明の一実施形態に係る「正極活物質（Ａ）」が満たす条件（ａ）及び条件（ｂ）を採用した。さらに条件（ａ）及び条件（ｂ）に関する具体的な条件は、本発明の一実施形態に係る「正極活物資（Ａ）」に関する条件として上記した通りとした。
　条件ａ及び条件ｂにかかる計算結果、並びにこれらの条件を満たすか否か（合否）の結果を表２に示す。なお、表２において、「Ｐ」はそれぞれの条件を満たすことを示し、「Ｆ」はそれぞれの条件を満たさないことを示す。 [Example 1] Selection of Substituent Element As a candidate oxide, an oxide No. 1 having each composition shown in Table 2 and having a fluorite-type crystal structure. 1 to No. 21 was selected and the calculation was performed.
For each of the above oxides, the contents of "(2) Determination of atomic arrangement" and "(3) Examination of condition A and condition B" described as "method for selecting a substituent" according to the embodiment of the present invention. It was determined whether the conditions A and B were satisfied by the method using the first-principles calculation according to the above. As the calculation software, Vienna Ab-initio Simulation Package (VASP) was used. Further, in the "method for selecting a substitution element" according to the embodiment of the present invention, the predetermined charging state under the above-mentioned conditions A and B is a state of being charged to 400 mAh / g, and the predetermined value of the abundance ratio under the condition A is 0. It was set to .53, and the predetermined value of the abundance ratio under the condition B was set to 0.11. That is, the condition (a) and the condition (b) satisfied by the "positive electrode active material (A)" according to the embodiment of the present invention are adopted. Further, the specific conditions relating to the condition (a) and the condition (b) are as described above as the conditions relating to the "positive electrode active material (A)" according to the embodiment of the present invention.
Table 2 shows the calculation results related to the conditions a and b, and the results of whether or not these conditions are satisfied (pass / fail). In Table 2, "P" indicates that each condition is satisfied, and "F" indicates that each condition is not satisfied.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に示される結果から、充電電気量が比較的大きい場合もクーロン効率が高い正極活物質に好適な置換元素の組み合わせとして、第一置換元素がＣｏであり、第二置換元素がＢ、Ｓｉ、Ｃ、Ｇａ、Ｍｇ、Ｐ、Ｔｉ又はＳｎである組み合わせ（Ｎｏ．３、４、６、８から１３及び１８）、並びに第一置換元素がＦｅ、Ｎｉ又はＣｕであり、第二置換元素がＢである組み合わせ（Ｎｏ．１９から２１）が良いと判断できる。上記結果を踏まえ、以下には、実際に上記Ｎｏ．１、２の各酸化物を比較例とし、上記Ｎｏ．３、８から１０の各酸化物を実施例としてそれぞれ実際に合成し、評価した。すなわち、上記の本発明の一実施形態に係る「置換元素の選択方法」によって、第一置換元素と第二置換元素との組み合わせとして、Ｃｏと、Ｂ、Ｓｉ又はＧａとの組み合わせを選択し、実際の評価を行った。 From the results shown in Table 2, as a combination of substitution elements suitable for the positive electrode active material having high Coulomb efficiency even when the amount of charging electricity is relatively large, the first substitution element is Co and the second substitution elements are B and Si. , C, Ga, Mg, P, Ti or Sn (No. 3, 4, 6, 8 to 13 and 18), and the first substitution element is Fe, Ni or Cu and the second substitution element is It can be judged that the combination (No. 19 to 21) of B is good. Based on the above results, the following is actually the above No. Using each of the oxides 1 and 2 as a comparative example, the above No. Each oxide of 3, 8 to 10 was actually synthesized and evaluated as an example. That is, the combination of Co and B, Si or Ga is selected as the combination of the first substitution element and the second substitution element by the above-mentioned "method for selecting a substitution element" according to the embodiment of the present invention. The actual evaluation was performed.
［合成例１］Ｌｉ６ＣｏＯ４の合成
　Ｌｉ２ＯとＣｏＯとを３：１のモル比で混合した後、窒素雰囲気下、９００℃で２０時間焼成し、Ｌｉ６ＣｏＯ４を合成した。 [Synthesis Example 1] Synthesis of Li 6 CoO 4 Li 2 O and CoO were mixed at a molar ratio of 3: 1 and then fired at 900 ° C. for 20 hours under a nitrogen atmosphere to synthesize Li 6 CoO 4 .
［合成例２］Ｌｉ３ＢＯ３の合成
　Ｌｉ２ＯとＢ２Ｏ３とを３：１のモル比で混合した後、窒素雰囲気下、９００℃で３時間焼成し、Ｌｉ３ＢＯ３を得た。 [Synthesis Example 2] Synthesis of Li 3 BO 3 Li 2 O and B 2 O 3 are mixed at a molar ratio of 3: 1 and then calcined at 900 ° C. for 3 hours in a nitrogen atmosphere to obtain Li 3 BO 3 . rice field.
［合成例３］Ｌｉ４ＳｉＯ４の合成
　Ｌｉ２ＯとＳｉＯ２とを２：１のモル比で混合した後、窒素雰囲気下、９００℃で２０時間焼成し、Ｌｉ４ＳｉＯ４を得た。 [Synthesis Example 3] Synthesis of Li 4 SiO 4 Li 2 O and SiO 2 were mixed at a molar ratio of 2: 1 and then calcined at 900 ° C. for 20 hours under a nitrogen atmosphere to obtain Li 4 SiO 4 .
［合成例４］Ｌｉ５ＧａＯ４の合成
　Ｌｉ２ＯとＧａ２Ｏ３とを５：１のモル比で混合した後、窒素雰囲気下、９００℃で２０時間焼成し、Ｌｉ５ＧａＯ４を得た。 [Synthesis Example 4] Synthesis of Li 5 GaO 4 Li 2 O and Ga 2 O 3 are mixed at a molar ratio of 5: 1 and then calcined at 900 ° C. for 20 hours under a nitrogen atmosphere to obtain Li 5 GaO 4 . rice field.
［合成例５］Ｌｉ５ＡｌＯ４の合成
　Ｌｉ２ＯとＡｌ２Ｏ３とを５：１のモル比で混合した後、大気雰囲気下、９００℃で２０時間焼成し、Ｌｉ５ＡｌＯ４を得た。 [Synthesis Example 5] Synthesis of Li 5 AlO 4 Li 2 O and Al 2 O 3 are mixed at a molar ratio of 5: 1 and then calcined at 900 ° C. for 20 hours in an atmospheric atmosphere to obtain Li 5 AlO 4 . rice field.
［実施例２］正極活物質の製造
　得られたＬｉ６ＣｏＯ４（１．６８０５ｇ）、得られたＬｉ３ＢＯ３（０．２３２３ｇ）、及びＬｉ２Ｏ（０．０８７２ｇ）を混合した後、アルゴン雰囲気下でタングステンカーバイド（ＷＣ）製ボールと共にＷＣ製ミル容器に投入し、遊星型ボールミル装置（ＦＲＩＴＳＣＨ社の「ｐｕｌｖｅｒｉｓｅｔｔｅ　５」）にて、回転数４００ｒｐｍで２時間処理した。このようなメカノケミカル法による処理により、実施例２の正極活物質（Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ）を得た。 [Example 2] Production of positive electrode active material After mixing the obtained Li 6 CoO 4 (1.6805 g), the obtained Li 3 BO 3 (0.2323 g), and Li 2 O (0.0872 g), It was put into a WC mill container together with a tungsten carbide (WC) ball under an argon atmosphere, and treated with a planetary ball mill device (“pulveristte 5” manufactured by FRITSCH) at a rotation speed of 400 rpm for 2 hours. By such treatment by the mechanochemical method, the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) of Example 2 was obtained.
［実施例３から５、比較例１、２］
　用いた材料を表３に示す通りとしたこと以外は実施例２と同様にして、実施例３から５及び比較例１、２の各正極活物質を得た。表３には、得られた正極活物質の組成式をあわせて示す。 [Examples 3 to 5, Comparative Examples 1 and 2]
The positive electrode active materials of Examples 3 to 5 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 2 except that the materials used were as shown in Table 3. Table 3 also shows the composition formulas of the obtained positive electrode active material.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
（正極活物質のエックス線回折測定）
　上記実施例２から５及び比較例１、２で得られた各正極活物質（酸化物）について、ＣｕＫα線を用いたエックス線回折測定を行った。気密性のエックス線回折測定用試料ホルダーを用い、アルゴン雰囲気下で各正極活物質の粉末試料を充填した。用いたエックス線回折装置、測定条件、及びデータ処理方法は上記の通りとした。いずれも、Ｌｉ２Ｏと同様の結晶構造（逆蛍石型の結晶構造）を主相として有することが確認できた。図３に実施例２、３及び比較例１、２の各正極活物質（酸化物）のエックス線回折図を示し、図４に実施例４、５の各正極活物質（酸化物）のエックス線回折図を示す。また、エックス線回折測定から求めた、実施例２から５及び比較例１、２の正極活物質（酸化物）における回折角２θが３３°付近の回折ピークの半値幅を表３に示す。 (X-ray diffraction measurement of positive electrode active material)
X-ray diffraction measurements using CuKα rays were performed on each of the positive electrode active materials (oxides) obtained in Examples 2 to 5 and Comparative Examples 1 and 2 above. Using an airtight sample holder for X-ray diffraction measurement, a powder sample of each positive electrode active material was filled under an argon atmosphere. The X-ray diffractometer used, the measurement conditions, and the data processing method were as described above. It was confirmed that all of them had the same crystal structure (inverted fluorite type crystal structure) as Li 2 O as the main phase. FIG. 3 shows an X-ray diffraction diagram of each positive electrode active material (oxide) of Examples 2 and 3 and Comparative Examples 1 and 2, and FIG. 4 shows an X-ray diffraction of each positive electrode active material (oxide) of Examples 4 and 5. The figure is shown. Table 3 shows the half-value width of the diffraction peak in which the diffraction angle 2θ in the positive electrode active materials (oxides) of Examples 2 to 5 and Comparative Examples 1 and 2 obtained from the X-ray diffraction measurement is around 33 °.
（正極の作製）
　アルゴン雰囲気下にて、実施例２から５及び比較例１、２で得られた各正極活物質（酸化物）０．７５ｇ、及びケッチェンブラック０．２０ｇを混合し、直径５ｍｍのＷＣ製ボールが２５０ｇ入った内容積８０ｍＬのＷＣ製ミル容器に投入し、蓋をした。これを上記と同じ遊星型ボールミル装置にセットし、公転回転数２００ｒｐｍで３０分間乾式粉砕することで、正極活物質とケッチェンブラックとの混合粉末を調製した。 (Preparation of positive electrode)
Under an argon atmosphere, 0.75 g of each positive electrode active material (oxide) obtained in Examples 2 to 5 and Comparative Examples 1 and 2 and 0.20 g of Ketjen Black were mixed, and a WC ball having a diameter of 5 mm was mixed. The mixture was placed in a WC mill container having an internal volume of 80 mL and containing 250 g, and the lid was closed. This was set in the same planetary ball mill device as above, and dried and pulverized at a revolution speed of 200 rpm for 30 minutes to prepare a mixed powder of the positive electrode active material and Ketjen black.
　上記各混合粉末９５質量部と、ポリテトラフルオロエチレン粉末５質量部を瑪瑙乳鉢で混錬し、シート状に成型した。このシートを直径１２ｍｍφの円盤状に打ち抜き、質量約０．０１ｇの正極シートを作製した。上記各正極シートをアルミニウムメッシュ製の正極基材（直径２１ｍｍφ）に圧着し、正極を得た。 95 parts by mass of each of the above mixed powders and 5 parts by mass of polytetrafluoroethylene powder were kneaded in an agate mortar and molded into a sheet. This sheet was punched into a disk shape having a diameter of 12 mmφ to prepare a positive electrode sheet having a mass of about 0.01 g. Each of the above positive electrode sheets was pressure-bonded to a positive electrode base material (diameter 21 mmφ) made of aluminum mesh to obtain a positive electrode.
（非水電解質蓄電素子（評価セル）の作製）
　ＥＣとＤＭＣとＥＭＣとを３０：３５：３５の体積比で混合した非水溶媒に、１ｍｏｌ／ｄｍ３の濃度でＬｉＰＦ６を溶解させ、非水電解質を調製した。得られた各正極を用い、直径２２ｍｍφの金属リチウムを負極とし、ポリプロピレン製セパレータを介して積層して容器に収納し、調製した非水電解質を３００μＬ注入して非水電解質蓄電素子（評価セル）を構成した。評価セルの作製は、アルゴン雰囲気下にて行った。 (Manufacturing of non-aqueous electrolyte power storage element (evaluation cell))
LiPF 6 was dissolved in a non-aqueous solvent in which EC, DMC and EMC were mixed at a volume ratio of 30:35:35 at a concentration of 1 mol / dm 3 to prepare a non-aqueous electrolyte. Using each of the obtained positive electrodes, using metallic lithium with a diameter of 22 mmφ as the negative electrode, laminating them via a polypropylene separator and storing them in a container, and injecting 300 μL of the prepared non-aqueous electrolyte into a non-aqueous electrolyte storage element (evaluation cell). Was configured. The evaluation cell was prepared in an argon atmosphere.
（充放電試験）
　実施例２から５及び比較例１、２の各正極活物質（酸化物）を用いて得られた評価セル（実施例６から９及び比較例３、４）について、アルゴン雰囲気下のグローブボックス内において、２５℃の環境下で以下の充放電試験を行った。電流密度は、正極が含有する正極活物質の質量あたり５０ｍＡ／ｇとし、定電流（ＣＣ）充放電を行った。充電から開始し、充電は、正極活物質の質量あたりの上限電気量４００ｍＡｈ／ｇ又は上限電圧４．５Ｖに到達した時点で終了とした。放電は、正極活物質の質量あたりの上限電気量４００ｍＡｈ／ｇ又は下限電圧１．５Ｖに到達した時点で終了とした。クーロン効率が９０％を下回るまで充放電のサイクルを繰り返した。１サイクル目の充電電気量及びクーロン効率、並びに９０％以上のクーロン効率が維持された充放電のサイクル数を表４に示す。 (Charging / discharging test)
The evaluation cells (Examples 6 to 9 and Comparative Examples 3 and 4) obtained by using the positive electrode active materials (oxides) of Examples 2 to 5 and Comparative Examples 1 and 2 were placed in a glove box under an argon atmosphere. The following charge / discharge test was performed in an environment of 25 ° C. The current density was 50 mA / g per mass of the positive electrode active material contained in the positive electrode, and constant current (CC) charging / discharging was performed. The charging was started, and the charging was terminated when the upper limit electric amount of 400 mAh / g or the upper limit voltage of 4.5 V per mass of the positive electrode active material was reached. The discharge was terminated when the upper limit electric amount of 400 mAh / g or the lower limit voltage of 1.5 V per mass of the positive electrode active material was reached. The charge / discharge cycle was repeated until the Coulomb efficiency fell below 90%. Table 4 shows the charge electricity amount and the Coulomb efficiency in the first cycle, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more is maintained.
　実施例２から４及び比較例１、２の各正極活物質（酸化物）について、さらに上記と同様の評価セル（実施例１０から１２及び比較例５、６）を別途準備し、２５℃の環境下で、充放電の正極活物質の質量あたりの上限電気量を６００ｍＡｈ／ｇにそれぞれ変更したこと以外は上記と同様の充放電試験をそれぞれ行った。各評価セルにおける１サイクル目の充電電気量及びクーロン効率、並びに９０％以上のクーロン効率が維持された充放電のサイクル数を表５に示す。 For each positive electrode active material (oxide) of Examples 2 to 4 and Comparative Examples 1 and 2, further evaluation cells similar to those described above (Examples 10 to 12 and Comparative Examples 5 and 6) were separately prepared, and the temperature was 25 ° C. Under the environment, the same charge / discharge tests as above were performed except that the upper limit electric amount per mass of the positive electrode active material for charge / discharge was changed to 600 mAh / g. Table 5 shows the amount of electricity charged and the Coulomb efficiency in the first cycle in each evaluation cell, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained.
　実施例２の正極活物質（酸化物）について、さらに上記と同様の評価セル（実施例１３から１５）を別途準備し、２５℃の環境下で、充放電の正極活物質の質量あたりの上限電気量を４５０ｍＡｈ／ｇ、５００ｍＡｈ／ｇ及び５５０ｍＡｈ／ｇにそれぞれ変更したこと以外は上記と同様の充放電試験をそれぞれ行った。各評価セルにおける１サイクル目の充電電気量及びクーロン効率、並びに９０％以上のクーロン効率が維持された充放電のサイクル数を表６に示す。表４、５に示した実施例２の正極活物質を用いた評価セル（実施例６、１０）における正極活物質の質量あたりの上限電気量を４００ｍＡｈ／ｇ及び６００ｍＡｈ／ｇとして行った充放電試験の結果もあわせて表６に示す。 For the positive electrode active material (oxide) of Example 2, the same evaluation cells as above (Examples 13 to 15) are separately prepared, and the upper limit per mass of the positive electrode active material for charging and discharging in an environment of 25 ° C. The same charge / discharge tests as above were performed except that the amount of electricity was changed to 450 mAh / g, 500 mAh / g, and 550 mAh / g, respectively. Table 6 shows the amount of electricity charged and the Coulomb efficiency in the first cycle in each evaluation cell, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained. Charging / discharging was performed with the upper limit electric amount per mass of the positive electrode active material in the evaluation cells (Examples 6 and 10) using the positive electrode active material of Example 2 shown in Tables 4 and 5 as 400 mAh / g and 600 mAh / g. The test results are also shown in Table 6.
　実施例４の正極活物質（酸化物）について、さらに上記と同様の評価セル（実施例１６）を別途準備し、２５℃の環境下で、充放電の正極活物質の質量あたりの上限電気量を５００ｍＡｈ／ｇに変更したこと以外は上記と同様の充放電試験を行った。評価セルにおける１サイクル目の充電電気量及びクーロン効率、並びに９０％以上のクーロン効率が維持された充放電のサイクル数を表７に示す。表４、５に示した実施例４の正極活物質を用いた評価セル（実施例８、１２）における正極活物質の質量あたりの上限電気量を４００ｍＡｈ／ｇ及び６００ｍＡｈ／ｇとして行った充放電試験の結果もあわせて表７に示す。 For the positive electrode active material (oxide) of Example 4, an evaluation cell (Example 16) similar to the above is separately prepared, and the upper limit electric amount per mass of the positive electrode active material for charging and discharging in an environment of 25 ° C. The same charge / discharge test as above was performed except that the value was changed to 500 mAh / g. Table 7 shows the amount of electricity charged and the Coulomb efficiency in the first cycle in the evaluation cell, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained. Charging / discharging was performed with the upper limit electric amount per mass of the positive electrode active material in the evaluation cells (Examples 8 and 12) using the positive electrode active material of Example 4 shown in Tables 4 and 5 as 400 mAh / g and 600 mAh / g. The test results are also shown in Table 7.
（充電ガス膨れ試験）
　実施例２及び比較例２の正極活物質（酸化物）について、さらに充電ガス膨れ試験用の評価セル（実施例１７及び比較例７）を別途準備した。得られた正極を用い、２５ｍｍ四方の金属リチウムを負極とし、ポリプロピレン製セパレータを介して積層し、金属樹脂複合フィルム製の外装体で密封した。上記充放電試験と同様に調製した非水電解質を３００μＬ封入して評価セル（蓄電素子）を構成し、大気下の恒温槽内において、２５℃の環境下で以下の充電試験（充電ガス膨れ試験）を行った。電流密度は、正極が含有する正極活物質の質量あたり２０ｍＡ／ｇとし、定電流（ＣＣ）充電を行った。充電は、正極活物質の質量あたりの上限電気量９００ｍＡｈ／ｇ又は上限電圧５．０Ｖに到達した時点で終了とした。充電は電圧及びセルの膨れ量を測定しながら行った。実施例２の正極活物質（Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ）を用いた評価セル（実施例１７）の充電時の正極電位及びセルの膨れ量の変化を表すグラフを図５に、比較例２の正極活物質（Ｌｉ１．３８９Ｃｏ０．１３９Ａｌ０．１１１Ｏ）を用いた評価セル（比較例７）の充電時の正極電位及びセルの膨れ量の変化を表すグラフを図６に示す。 (Charging gas swelling test)
For the positive electrode active materials (oxides) of Example 2 and Comparative Example 2, evaluation cells for charging gas swelling test (Example 17 and Comparative Example 7) were separately prepared. Using the obtained positive electrode, 25 mm square metallic lithium was used as the negative electrode, laminated via a polypropylene separator, and sealed with an exterior body made of a metal resin composite film. An evaluation cell (storage element) is formed by enclosing 300 μL of a non-aqueous electrolyte prepared in the same manner as in the above charge / discharge test, and the following charging test (charging gas swelling test) is performed in a constant temperature bath under the atmosphere at 25 ° C. ) Was performed. The current density was 20 mA / g per mass of the positive electrode active material contained in the positive electrode, and constant current (CC) charging was performed. Charging was terminated when the upper limit electric amount of 900 mAh / g per mass of the positive electrode active material or the upper limit voltage of 5.0 V was reached. Charging was performed while measuring the voltage and the amount of swelling of the cell. FIG. 6 is a graph showing changes in the positive electrode potential and the amount of swelling of the cell during charging of the evaluation cell (Example 17) using the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) of Example 2. 5 shows changes in the positive electrode potential and the amount of cell swelling during charging of the evaluation cell (Comparative Example 7) using the positive electrode active material (Li 1.389 Co 0.139 Al 0.111 O) of Comparative Example 2. The graph is shown in FIG.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　表４に示されるように、実施例１において本発明の一実施形態に係る置換元素の選択方法によって好適な置換元素の組み合わせと判断でき、選択した第一置換元素がＣｏであり第二置換元素がＢ、Ｓｉ又はＧａである正極活物質を用いた実施例６から９においては、クーロン効率が高く、９０％以上のクーロン効率が維持された充放電のサイクル数も多かった。また、表５に示されるように、充電電気量がより大きい場合、実施例１において本発明の一実施形態に係る置換元素の選択方法によって好適な置換元素の組み合わせと判断でき、選択した第一置換元素がＣｏであり第二置換元素がＢ又はＳｉである正極活物質を用いた実施例１０から１２においては、クーロン効率が高いという効果が顕著に表れた。さらに、表６、７に示されるように、実施例１において本発明の一実施形態に係る置換元素の選択方法によって好適な置換元素の組み合わせと判断でき、選択した第一置換元素がＣｏであり第二置換元素がＢ又はＳｉである正極活物質（Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ又はＬｉ１．３８９Ｃｏ０．１９４Ｓｉ０．０５６Ｏ）を用いた場合、充電電気量４００ｍＡｈ／ｇ以上６００ｍＡｈ／ｇ以下の範囲でクーロン効率が高く、充放電を繰り返してもこの高いクーロン効率が維持されることが確認できた。
　また、図５と図６の対比からわかるように、実施例２で得られた正極活物質（Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ）を用いた実施例１７（図５）は、比較例２で得られた正極活物質（Ｌｉ１．３８９Ｃｏ０．１３９Ａｌ０．１１１Ｏ）を用いた比較例７（図６）と比較して、ガス膨れが開始するまでの充電電気量が大きく、充電時のガス膨れが抑制されていた。すなわち、実施例２で得られた正極活物質は、酸素の放出といった充電に伴う不可逆変化が生じ難いことがわかる。条件Ｂに係る存在比（酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比）が小さい実施例２で得られた正極活物質（Ｌｉ１．４４４Ｃｏ０．１９４Ｂ０．０５６Ｏ）を用いた場合、結晶構造中の酸素の安定性が高くなっていることが裏付けられているといえる。また、各実施例の正極活物質においては、このような構造安定性の高さにより、高いクーロン効率やその維持されやすさが改善されていると推測される。 As shown in Table 4, it can be determined in Example 1 that it is a suitable combination of substitution elements according to the method for selecting a substitution element according to the embodiment of the present invention, and the selected first substitution element is Co and the second substitution element. In Examples 6 to 9 using the positive electrode active material of B, Si or Ga, the Coulomb efficiency was high, and the number of charge / discharge cycles in which the Coulomb efficiency of 90% or more was maintained was also large. Further, as shown in Table 5, when the amount of charging electricity is larger, it can be determined that the combination of the substitution elements is suitable by the method of selecting the substitution element according to the embodiment of the present invention in Example 1, and the first selection is made. In Examples 10 to 12 using the positive electrode active material in which the substitution element is Co and the second substitution element is B or Si, the effect of high Coulomb efficiency was remarkably shown. Further, as shown in Tables 6 and 7, it can be determined that the combination of the substitution elements is suitable by the method of selecting the substitution element according to the embodiment of the present invention in Example 1, and the selected first substitution element is Co. When a positive electrode active material (Li 1.444 Co 0.194 B 0.056 O or Li 1.389 Co 0.194 Si 0.056 O) in which the second substitution element is B or Si is used, the amount of electricity charged is charged. It was confirmed that the coulombic efficiency was high in the range of 400 mAh / g or more and 600 mAh / g or less, and that this high coulombic efficiency was maintained even after repeated charging and discharging.
Further, as can be seen from the comparison between FIGS. 5 and 6, Example 17 (FIG. 5) using the positive electrode active material (Li 1.444 Co 0.194 B 0.056 O) obtained in Example 2 is Compared with Comparative Example 7 (FIG. 6) using the positive electrode active material (Li 1.389 Co 0.139 Al 0.111 O) obtained in Comparative Example 2, charging electricity until gas swelling started. The amount was large, and gas swelling during charging was suppressed. That is, it can be seen that the positive electrode active material obtained in Example 2 is unlikely to undergo irreversible changes due to charging such as oxygen release. The positive electrode active material (Li 1. When 444 Co 0.194 B 0.056 O) is used, it can be said that the stability of oxygen in the crystal structure is high. Further, in the positive electrode active material of each example, it is presumed that such high structural stability improves high Coulomb efficiency and its maintainability.
　本発明は、パーソナルコンピュータ、通信端末等の電子機器、自動車などの電源として使用される非水電解質蓄電素子、蓄電装置、及びこれに備わる正極、正極活物質などに適用できる。 The present invention can be applied to personal computers, electronic devices such as communication terminals, non-aqueous electrolyte power storage elements used as power sources for automobiles, power storage devices, and positive electrodes and positive electrode active materials provided therein.
１　　非水電解質蓄電素子
２　　電極体
３　　容器
４　　正極端子
４１　正極リード
５　　負極端子
５１　負極リード
２０　蓄電ユニット
３０　蓄電装置 1 Non-aqueous electrolyte power storage element 2 Electrode body 3 Container 4 Positive terminal 41 Positive lead 5 Negative terminal 51 Negative lead 20 Power storage unit 30 Power storage device

Claims (14)

  1. 　リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質における上記第一置換元素及び上記第二置換元素を選択する方法であって、
    　上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、
    　上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、
    　上記第一置換元素及び上記第二置換元素として、第一原理計算に基づく計算結果が下記条件Ａ及び条件Ｂを満たす組み合わせを選択することを備える置換元素の選択方法。
    　条件Ａ：上記酸化物の所定の充電状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が所定値以上であること
    　条件Ｂ：上記酸化物の所定の充電状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が所定値以下であること     It is a method of selecting the first-substituted element and the second-substituted element in a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and containing an oxide having an inverted fluorite-type crystal structure. hand,
    The first substitution element is an element other than technetium and tungsten, which belongs to any of Group 6 to Group 11.
    The second substitution element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16.
    A method for selecting a substitution element, which comprises selecting a combination of the first substitution element and the second substitution element whose calculation result based on the first-principles calculation satisfies the following conditions A and B.
    Condition A: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in the predetermined charged state of the oxide is equal to or higher than the predetermined value. The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in the predetermined charged state of the oxide is not more than the predetermined value.
  2. 　リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、
    　上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、
    　上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、
    　上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質。
    　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
    　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること     It contains lithium, a first-substituted element and a second-substituted element, and contains an oxide having an inverted fluorite-type crystal structure.
    The first substitution element is an element other than technetium and tungsten, which belongs to any of Group 6 to Group 11.
    The second substitution element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16.
    A positive electrode active material in which the first substitution element and the second substitution element are a combination in which the calculation result based on the first principle calculation satisfies the following conditions a and b.
    Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  3. 　上記第二置換元素が、シャノンの有効イオン半径が０．６０Å未満である元素である請求項２に記載の正極活物質。 The positive electrode active material according to claim 2, wherein the second substitution element is an element having an effective ion radius of Shannon of less than 0.60 Å.
  4. 　上記第一置換元素が、コバルト、鉄、銅、マンガン、ニッケル、クロム又はこれらの組み合わせであり、
    　上記第二置換元素が、ホウ素、炭素、マグネシウム、ケイ素、リン、チタン、ガリウム、スズ又はこれらの組み合わせである請求項２又は３に記載の正極活物質。     The first substitution element is cobalt, iron, copper, manganese, nickel, chromium or a combination thereof.
    The positive electrode active material according to claim 2 or 3, wherein the second substituent is boron, carbon, magnesium, silicon, phosphorus, titanium, gallium, tin or a combination thereof.
  5. 　請求項１に記載の置換元素の選択方法を用いて選択された第一置換元素及び第二置換元素並びにリチウムを含み、かつ逆蛍石型の結晶構造を有する酸化物を含有し、
    　上記条件Ａ及び条件Ｂにおける所定の充電状態が４００ｍＡｈ／ｇまで充電した状態であり、
    　上記条件Ａにおける上記存在比の所定値が０．５３であり、
    　上記条件Ｂにおける上記存在比の所定値が０．１１である正極活物質。     It contains the first and second substitution elements selected by the method for selecting a substitution element according to claim 1, and an oxide containing lithium and having an inverted fluorite-type crystal structure.
    The predetermined charging state under the above conditions A and B is a state of being charged to 400 mAh / g.
    The predetermined value of the abundance ratio under the above condition A is 0.53.
    A positive electrode active material in which the predetermined value of the abundance ratio under the above condition B is 0.11.
  6. 　上記酸化物のＣｕＫα線を用いたエックス線回折図において、回折角２θが３３°付近の回折ピークの半値幅が０．３°以上である請求項２から５のいずれかに記載の正極活物質。 The positive electrode active material according to any one of claims 2 to 5, wherein the half-value width of the diffraction peak near the diffraction angle 2θ of 33 ° is 0.3 ° or more in the X-ray diffraction diagram using the CuKα ray of the oxide.
  7. 　請求項２から６のいずれかに記載の正極活物質を含有する非水電解質蓄電素子用の正極。 A positive electrode for a non-aqueous electrolyte power storage element containing the positive electrode active material according to any one of claims 2 to 6.
  8. 　請求項７に記載の正極を備える非水電解質蓄電素子。 The non-aqueous electrolyte power storage element provided with the positive electrode according to claim 7.
  9. 　非水電解質蓄電素子を複数個備え、且つ請求項８に記載の非水電解質蓄電素子を一以上備える蓄電装置。 A power storage device including a plurality of non-aqueous electrolyte power storage elements and one or more of the non-water electrolyte power storage elements according to claim 8.
  10. 　リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質を製造する方法であって、
    　請求項１に記載の置換元素の選択方法を用いて選択された上記第一置換元素及び上記第二置換元素を含む材料を処理することを備える正極活物質の製造方法。     A method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and an oxide having an inverted fluorite-type crystal structure.
    A method for producing a positive electrode active material, which comprises treating a material containing the first substitution element and the second substitution element selected by using the method for selecting a substitution element according to claim 1.
  11. 　請求項１に記載の置換元素の選択方法により、上記第一置換元素及び上記第二置換元素の組み合わせを選択すること、及び
    　リチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理すること
    　を備える正極活物質の製造方法。     By the method for selecting a substitution element according to claim 1, a combination of the first substitution element and the second substitution element can be selected, and a material containing lithium, oxygen, the first substitution element and the second substitution element. A method for producing a positive electrode active material, which comprises treating with a mechanochemical method.
  12. 　リチウム、第一置換元素及び第二置換元素を含み、かつ逆蛍石型の結晶構造を有する酸化物を含有する正極活物質の製造方法であって、
    　リチウム、酸素、上記第一置換元素及び上記第二置換元素を含む材料をメカノケミカル法により処理することを備え、
    　上記第一置換元素が、第６族から第１１族のいずれかに属する、テクネチウム及びタングステン以外の元素であり、
    　上記第二置換元素が、第２族から第５族及び第１２族から第１６族のいずれかに属する、窒素、酸素、硫黄及びセレン以外の元素であり、
    　上記第一置換元素及び上記第二置換元素が、第一原理計算に基づく計算結果が下記条件ａ及び条件ｂを満たす組み合わせである正極活物質の製造方法。
    　条件ａ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての上記第一置換元素に対する、酸素の配位数が４配位である第一置換元素の存在比が０．５３以上であること
    　条件ｂ：上記酸化物を４００ｍＡｈ／ｇまで充電した状態での全ての酸素に対する、電荷が－０．５より大きい酸素の存在比が０．１１以下であること     A method for producing a positive electrode active material containing lithium, a first-substituted element and a second-substituted element, and an oxide having an inverted fluorite-type crystal structure.
    A material containing lithium, oxygen, the first substitution element and the second substitution element is provided by the mechanochemical method.
    The first substitution element is an element other than technetium and tungsten, which belongs to any of Group 6 to Group 11.
    The second substitution element is an element other than nitrogen, oxygen, sulfur and selenium, which belongs to any of Group 2 to Group 5 and Group 12 to Group 16.
    A method for producing a positive electrode active material, wherein the first substitution element and the second substitution element are a combination in which the calculation result based on the first principle calculation satisfies the following conditions a and b.
    Condition a: The abundance ratio of the first substituent having an oxygen coordination number of 4 to all the first substituents in a state where the oxide is charged to 400 mAh / g is 0.53 or more. Condition b: The abundance ratio of oxygen having a charge greater than -0.5 to all oxygen in a state where the above oxide is charged to 400 mAh / g is 0.11 or less.
  13. 　請求項２から６のいずれかに記載の正極活物質又は請求項１０から１２のいずれかに記載の正極活物質の製造方法で得られた正極活物質を用いて正極を作製することを備える非水電解質蓄電素子用の正極の製造方法。 The present invention comprises producing a positive electrode using the positive electrode active material according to any one of claims 2 to 6 or the positive electrode active material obtained by the method for producing a positive electrode active material according to any one of claims 10 to 12. A method for manufacturing a positive electrode for a water electrolyte storage element.
  14. 　請求項１３に記載の正極の製造方法を備える非水電解質蓄電素子の製造方法。 A method for manufacturing a non-aqueous electrolyte power storage element comprising the method for manufacturing a positive electrode according to claim 13.
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