WO2015151566A1 - All-solid-state lithium cell - Google Patents

All-solid-state lithium cell Download PDF

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Publication number
WO2015151566A1
WO2015151566A1 PCT/JP2015/052276 JP2015052276W WO2015151566A1 WO 2015151566 A1 WO2015151566 A1 WO 2015151566A1 JP 2015052276 W JP2015052276 W JP 2015052276W WO 2015151566 A1 WO2015151566 A1 WO 2015151566A1
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Prior art keywords
positive electrode
solid
lithium
electrode plate
oriented
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PCT/JP2015/052276
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French (fr)
Japanese (ja)
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幸信 由良
一博 山本
立 田中
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日本碍子株式会社
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Priority to JP2016511416A priority Critical patent/JP6433086B2/en
Publication of WO2015151566A1 publication Critical patent/WO2015151566A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0562—Solid materials
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0068—Solid electrolytes inorganic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0068—Solid electrolytes inorganic
    • H01M2300/0071—Oxides
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to an all solid lithium battery.
  • a liquid electrolyte such as an organic solvent using a flammable organic solvent as a diluent solvent has been conventionally used as a medium for moving ions.
  • a battery using such an electrolytic solution may cause problems such as leakage of the electrolytic solution, ignition, and explosion.
  • Patent Document 1 Japanese Patent Laid-Open No. 2013-1057078 describes a positive electrode layer made of lithium cobaltate (LiCoO 2 ), a negative electrode layer made of metallic lithium, and a lithium phosphate oxynitride glass electrolyte (LIPON).
  • LiCoO 2 lithium cobaltate
  • LiIPON lithium phosphate oxynitride glass electrolyte
  • a thin-film lithium secondary battery including a solid electrolyte layer that can be formed is disclosed, and it is described that a positive electrode layer is formed by sputtering and has a thickness in the range of 1 to 15 ⁇ m.
  • an all-solid battery has been proposed in which the positive electrode is made thicker to try to improve the capacity.
  • Patent Document 2 Japanese Patent Publication No.
  • 2009-516359 discloses a positive electrode having a thickness greater than about 4 ⁇ m and less than about 200 ⁇ m, a solid electrolyte having a thickness of less than about 10 ⁇ m, and a negative electrode having a thickness of less than about 30 ⁇ m.
  • An all-solid battery is disclosed. In these documents, there is no description that the positive electrode active material is oriented.
  • Patent Document 3 Japanese Patent Laid-Open No. 2012-009193
  • Patent Document 4 Japanese Patent Laid-Open No. 2012-009194
  • Patent Document 5 Japanese Patent No.
  • LLZ Li—La—Zr—O based composite oxide
  • Patent Document 6 Japanese Patent Laid-Open No. 2011-051800 discloses that the addition of Al in addition to Li, La, and Zr, which are basic elements of LLZ, can improve the density and lithium ion conductivity. ing.
  • Patent Document 7 Japanese Patent Application Laid-Open No.
  • Patent Document 8 Japanese Patent Laid-Open No. 2011-073963
  • the density can be further improved by setting the molar ratio of Li to La to 2.0 to 2.5. Is disclosed.
  • JP 2013-105708 A Special table 2009-516359 gazette JP 2012-009193 A JP 2012-009194 A Japanese Patent No. 4745463 JP 2011-051800 A JP 2011-073962 A JP 2011-073963 A
  • the present inventors now combine a positive electrode plate having a specific composition with a solid electrolyte layer having a specific composition, and control the thickness and degree of orientation of the positive electrode plate within a predetermined range.
  • the present inventors have found that although the configuration is suitable for improving the capacity and energy density, deterioration of battery characteristics (particularly, increase in resistance value) due to repeated charge / discharge can be significantly reduced.
  • an object of the present invention is to provide an all-solid-state lithium battery that can significantly reduce deterioration of battery characteristics (particularly increase in resistance value) due to repeated charge and discharge, while having a configuration suitable for improving capacity and energy density. There is to do.
  • a solid electrolyte layer provided on the positive electrode
  • An example of the all-solid lithium battery according to the invention is shown schematically in all-solid-state lithium batteries Figure 1.
  • An all solid lithium battery 10 shown in FIG. 1 includes a positive electrode plate 12, a solid electrolyte layer 14 provided on the positive electrode plate 12, and a negative electrode layer 16 provided on the solid electrolyte layer 14.
  • the positive electrode plate 12 is made of an oriented polycrystal having a thickness of 10 ⁇ m or more and an orientation degree of 15 to 85%.
  • the solid electrolyte layer 14 is made of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material. According to the all-solid-state lithium battery having such a configuration, although it is a configuration suitable for improving the capacity and energy density, the deterioration of battery characteristics (particularly the increase in resistance value) due to repeated charge and discharge is significantly reduced. Can do.
  • each composition of the positive electrode plate 12 and the solid electrolyte layer 14 is known to improve battery characteristics as described in Patent Documents 3 to 8, for example.
  • the positive electrode plate 12 is made of an oriented polycrystal and the thickness is increased to 10 ⁇ m or more.
  • a positive electrode layer having a thickness of 10 ⁇ m or more is not known as in Patent Documents 1 and 2, but the capacity and energy density are increased as expected only by forming the positive electrode layer to be thick. Cannot be obtained. This is considered to be because, in the case of a conventional positive electrode layer in which the positive electrode active material is not oriented, it is difficult to efficiently remove and insert lithium ions over the entire thickness of the thick positive electrode layer.
  • the positive electrode plate 12 used in the present invention is an oriented polycrystal composed of a plurality of lithium transition metal oxide particles oriented in a certain direction, the thickness of the positive electrode layer can be increased even if a thick positive electrode active material is provided. It is easy to remove and insert high-efficiency lithium ions throughout, and the capacity improvement effect brought about by the thick positive electrode active material can be maximized. For example, lithium existing on the side of the thick positive electrode layer away from the solid electrolyte can be sufficiently extracted. Such an increase in capacity can greatly improve the energy density of the all-solid-state battery.
  • the all solid lithium battery of the present invention battery performance with high capacity and energy density can be obtained. Therefore, it is possible to realize a highly safe all-solid battery having a high capacity and a high energy density while being relatively thin or small.
  • the positive electrode plate 12 can be composed of a ceramic sintered body, it can be easily formed thicker than a film formed by a vapor phase method such as sputtering, and the composition is accurately controlled by strictly weighing the raw material powder. There is also an advantage that it is easy to do.
  • the battery characteristics can be deteriorated (especially the resistance value is increased) as charging and discharging are repeated, although the combination of the positive electrode plate 12 and the solid electrolyte layer 14 is desirable as described above.
  • the higher the degree of orientation of the positive electrode plate 12 the better the battery characteristics could be improved.
  • the battery resistance actually increased with repeated charge and discharge. Deterioration of battery characteristics can occur. This is a phenomenon particularly seen when a thick oriented positive electrode plate having the above specific composition is joined to a solid electrolyte made of a Li—La—Zr—O-based and / or LiPON-based ceramic material (for example, a sulfur-based solid electrolyte).
  • the above phenomenon is not observed when bonded to a solid electrolyte made of a material).
  • the above-described increase in the resistance value of the battery can be significantly reduced by controlling the degree of orientation of the oriented polycrystalline body constituting the positive electrode plate 12 to 15 to 85%.
  • the mechanism that brings about this advantageous effect is not necessarily clear, the expansion and contraction of the positive electrode plate 12 due to the desorption / insertion of lithium ions accompanying charging / discharging is suppressed to be low within the above-mentioned orientation degree range.
  • the positive electrode plate 12 is made of an oriented polycrystal composed of a plurality of lithium transition metal oxide particles having a layered rock salt structure.
  • the layered rock salt structure has a property that the oxidation-reduction potential decreases due to occlusion of lithium ions and the oxidation-reduction potential increases due to elimination of lithium ions, and a composition containing a large amount of Ni is particularly preferable.
  • the layered rock salt structure is a crystal structure in which transition metal layers other than lithium and lithium layers are alternately stacked with an oxygen atom layer interposed therebetween, that is, an ion layer and lithium ions of transition metals other than lithium.
  • compositions are nickel and cobalt among lithium transition metal oxides having a layered rock salt structure.
  • nickel and cobalt By including nickel and cobalt, the expansion / contraction rate of the positive electrode plate 12 during charging / discharging can be significantly reduced.
  • Typical examples of such a composition include nickel-lithium cobaltate, cobalt-nickel- Examples thereof include lithium manganate, nickel / cobalt / lithium aluminum oxide, etc.
  • the lithium transition metal oxide particles or their oriented polycrystals include Mg, Al, Si, Ca, Ti, V, Cr, Fe, Cu, Zn.
  • Ga, Ge, Sr, Y, Zr, Nb, Mo, Ag, Sn, Sb, Te, Ba, Bi, etc. are further doped or in a form equivalent thereto (for example, a partial surface layer of crystal grains) A small amount may be added by solid solution or segregation).
  • the positive electrode plate 12 is made of an oriented polycrystal formed of a plurality of lithium transition metal oxide particles.
  • This oriented polycrystal is preferably composed of a plurality of lithium transition metal oxide particles oriented in a certain direction.
  • the certain direction is preferably a lithium ion conduction direction.
  • a specific crystal plane of each particle constituting the positive electrode plate 12 is oriented in a direction from the positive electrode plate 12 toward the negative electrode layer 16.
  • the lithium transition metal oxide particles are preferably particles formed in a plate shape having a thickness of about 2 to 100 ⁇ m.
  • the specific crystal plane described above is a (003) plane, and the (003) plane is oriented in a direction from the positive electrode plate 12 toward the negative electrode layer 16. Thereby, it does not become a resistance at the time of insertion / removal of the lithium ion with respect to the positive electrode plate 12, but can release many lithium ions at the time of high input (charge) and much at the time of high output (discharge). Can accept lithium ions.
  • the (101) plane or the (104) plane other than the (003) plane may be oriented along the plate surface of the positive electrode plate 12.
  • Patent Documents 3 to 5 can be referred to, and the disclosure contents of these documents are incorporated herein by reference.
  • the positive electrode plate 12 is made of an oriented polycrystal, and this oriented polycrystal is 15 to 85%, preferably 20 to 80%, more preferably 30 to 75%, still more preferably 40 to 75%, particularly preferably. It has an orientation degree of 45-75%, most preferably 40-70%.
  • the upper limit value and the lower limit value of these various orientation degree ranges may be arbitrarily combined.
  • the degree of orientation is at least 15%, preferably at least 20%, more preferably at least 30%, even more preferably at least 40%, particularly preferably at least 45% with respect to the lower limit, and with respect to the upper limit. 85% or less, preferably 80% or less, more preferably 75% or less, and most preferably 70% or less.
  • this degree of orientation is such that the plate surface of the positive electrode plate 12 is the sample surface, and X-ray diffraction is in the range of 10 ° to 70 ° at 2 ⁇ using an XRD apparatus (eg, TTR-III, manufactured by Rigaku Corporation).
  • the degree of orientation may be calculated based on the following formula using the obtained XRD profile according to the Lotgering method, under the conditions of 2 ° / min and a step width of 0.02 °.
  • I is the diffraction intensity of the positive electrode plate sample
  • I 0 is the diffraction intensity of the non-oriented reference sample.
  • HTL is the diffraction line for which the degree of orientation is to be evaluated
  • (00l) (l is (For example, 3, 6 and 9.)
  • (hkl) corresponds to all diffraction lines.)
  • the non-oriented reference sample is a sample having the same configuration as the positive electrode plate sample except that it is non-oriented.
  • the non-oriented reference sample can be obtained by pulverizing the positive electrode plate sample with a mortar to make it non-oriented. .
  • the (001) diffraction line is removed because the plane corresponding to this diffraction line (for example, the (003) plane) is the in-plane direction (the direction parallel to the plane). This is because the movement of lithium ions is hindered when the surface is oriented along the plate surface of the positive electrode plate 12.
  • the plurality of lithium transition metal oxide particles are preferably oriented in such a direction that the (003) plane of the layered rock salt structure intersects the plate surface of the positive electrode plate 12. That is, the direction that intersects the plate surface of the positive electrode plate 12 is the lithium ion conduction direction. According to this configuration, the (003) surface of each particle constituting the positive electrode plate 12 extends from the positive electrode plate 12 to the negative electrode layer. It will be oriented in the direction towards 16.
  • the oriented polycrystalline body constituting the positive electrode plate 12 is suitable for making it thicker than the non-oriented polycrystalline body.
  • the thickness of the oriented polycrystal is preferably 10 ⁇ m or more, more preferably 13 ⁇ m or more, further preferably 16 ⁇ m or more, particularly preferably 20 ⁇ m or more, and most preferably from the viewpoint of increasing the active material capacity per unit area. It is 25 ⁇ m or more.
  • the upper limit value of the thickness is not particularly limited, but is preferably less than 100 ⁇ m, more preferably 90 ⁇ m or less, and even more preferably 80 ⁇ m or less from the viewpoint of reducing deterioration of battery characteristics (particularly increase in resistance value) due to repeated charge / discharge. Particularly preferably, it is 70 ⁇ m or less, and most preferably 60 ⁇ m.
  • the positive electrode plate 12 is preferably formed in a sheet shape.
  • a preferred method for producing a positive electrode active material (hereinafter referred to as a positive electrode active material sheet) formed in the form of a sheet will be described later.
  • the positive electrode plate 12 may be constituted by one positive electrode active material sheet, or the positive electrode plate 12 may be constituted by arranging a plurality of small pieces obtained by dividing the positive electrode active material sheet in layers. Good.
  • the surface of the positive electrode plate 12 on the solid electrolyte layer 14 side preferably has an arithmetic average roughness Ra of more than 0.05 ⁇ m and less than 3.0 ⁇ m, more preferably 0.10 to 2.5 ⁇ m, and still more preferably 0.8. It has an arithmetic average roughness Ra of 13 to 2.0 ⁇ m, particularly preferably 0.16 to 1.5 ⁇ m, most preferably 0.20 to 1.0 ⁇ m.
  • the arithmetic average roughness Ra is a value determined according to JIS B 0601-2001, and can be measured with a commercially available surface roughness measuring machine.
  • the contact point between the positive electrode plate 12 and the solid electrolyte layer 14 (this is lithium ion conduction) with an appropriate surface roughness.
  • a desirable interface excellent in adhesion, in which the resistance value is not easily increased by repeated charge / discharge between the positive electrode plate 12 and the solid electrolyte layer 14 due to moderately high smoothness. Can be formed.
  • the arithmetic average roughness Ra within the above range may be realized by appropriately adjusting the manufacturing conditions of the positive electrode plate 12 (for example, refining the raw material particle size, firing schedule, densification of the molded body, etc.) You may implement
  • the oriented polycrystalline body constituting the positive electrode plate 12 preferably has a relative density of 75 to 99.97%, more preferably 80 to 99.95%, still more preferably 90 to 99.90%, and particularly preferably 95. It has a relative density of ⁇ 99.88%, most preferably 97-99.85%. From the viewpoint of capacity and energy density, it is basically desirable that the relative density be high, but if it is within the above range, the resistance value is unlikely to increase even after repeated charge and discharge. It is thought that this is because the positive electrode plate 12 can be appropriately expanded and contracted as lithium is deinserted and the stress can be relieved by the relative density.
  • the solid electrolyte layer 14 is composed of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material.
  • the Li—La—Zr—O-based material is an oxide sintered body having a garnet-type or garnet-type similar crystal structure including Li, La, Zr, and O. Specifically, Li 7 A garnet-based ceramic material such as La 3 Zr 2 O 12 . As such materials, those described in Patent Documents 6 to 8 can also be used, and the disclosure content of these documents is incorporated herein by reference.
  • the garnet-based ceramic material is a lithium ion conductive material that does not react even when directly contacted with the negative electrode lithium, and in particular, a garnet-type or garnet-type similar crystal structure including Li, La, Zr, and O Oxide sintered bodies having excellent sinterability and easy densification and high ionic conductivity.
  • a garnet-type or garnet-like crystal structure of this type of composition is called an LLZ crystal structure, and is referred to as an X-ray diffraction file No. of CSD (Cambridge Structural Database). It has an XRD pattern similar to 422259 (Li 7 La 3 Zr 2 O 12 ). In addition, No.
  • the constituent elements are different and the Li concentration in the ceramics may be different, so the diffraction angle and the diffraction intensity ratio may be different.
  • the molar ratio Li / La of Li to La is preferably 2.0 or more and 2.5 or less, and the molar ratio Zr / La to La is preferably 0.5 or more and 0.67 or less.
  • This garnet-type or garnet-like crystal structure may further comprise Nb and / or Ta. That is, by replacing a part of Zr of LLZ with one or both of Nb and Ta, the conductivity can be improved as compared with that before the substitution.
  • the substitution amount (molar ratio) of Zr with Nb and / or Ta is preferably set such that the molar ratio of (Nb + Ta) / La is 0.03 or more and 0.20 or less.
  • the garnet-based oxide sintered body preferably further contains Al, and these elements may exist in the crystal lattice or may exist in other than the crystal lattice.
  • the amount of Al added is preferably 0.01 to 1% by mass of the sintered body, and the molar ratio Al / La to La is preferably 0.008 to 0.12.
  • Such LLZ-based ceramics can be produced according to a known technique as described in Patent Documents 6 to 8, or by appropriately modifying it, and the disclosure of these documents is referred to in this specification. Is incorporated.
  • LiPON lithium phosphate oxynitride ceramic material
  • LiPON is a group of compounds represented by the composition of Li 2.9 PO 3.3 N 0.46 .
  • Li a PO b N c (wherein a is 2 to 4 and b is 3 to 5 , C is 0.1 to 0.9).
  • the dimensions of the solid electrolyte layer 14 are not particularly limited, but the thickness is preferably 0.0005 mm to 0.5 mm, more preferably 0.001 mm to 0.1 mm, and still more preferably, from the viewpoints of charge / discharge rate characteristics and mechanical strength. Is 0.005 to 0.05 mm.
  • various particle jet coating methods, solid phase methods, solution methods, gas phase methods, and direct bonding methods can be used.
  • the particle jet coating method include an aerosol deposition (AD) method, a gas deposition (GD) method, a powder jet deposition (PJD) method, a cold spray (CS) method, and a thermal spraying method.
  • the aerosol deposition (AD) method is particularly preferable because it can form a film at room temperature, and does not cause a composition shift during the process or formation of a high resistance layer due to a reaction with the positive electrode plate.
  • the solid phase method include a tape lamination method and a printing method.
  • the tape lamination method is preferable because the solid electrolyte layer 14 can be formed thin and the thickness can be easily controlled.
  • the solution method include a solvothermal method, a hydrothermal synthesis method, a sol-gel method, a precipitation method, a microemulsion method, and a solvent evaporation method.
  • the hydrothermal synthesis method is particularly preferable in that it is easy to obtain crystal grains having high crystallinity at a low temperature.
  • microcrystals synthesized using these methods may be deposited on the positive electrode or may be directly deposited on the positive electrode.
  • the gas phase method examples include laser deposition (PLD) method, sputtering method, evaporation condensation (PVD) method, gas phase reaction method (CVD) method, vacuum deposition method, molecular beam epitaxy (MBE) method and the like.
  • the laser deposition (PLD) method is particularly preferable because there is little composition deviation and a film with relatively high crystallinity can be easily obtained.
  • the direct bonding (direct bonding) method is a method in which the surfaces of the solid electrolyte layer 14 and the positive electrode plate 12 formed in advance are chemically activated and bonded at a low temperature. For activation of the interface, plasma or the like may be used, or chemical modification of a functional group such as a hydroxyl group may be used.
  • the interface between the positive electrode plate 12 and the solid electrolyte layer 14 may be subjected to a treatment for reducing the interface resistance.
  • a treatment for reducing the interface resistance includes niobium oxide, titanium oxide, tungsten oxide, tantalum oxide, lithium-nickel composite oxide, lithium-titanium composite oxide, lithium-niobium compound, lithium-tantalum compound, lithium- This can be done by coating the surface of the positive electrode plate 12 and / or the surface of the solid electrolyte layer 14 with a tungsten compound, a lithium / titanium compound, and any combination or composite oxide thereof.
  • a film can exist at the interface between the positive electrode plate 12 and the solid electrolyte layer 14, and the thickness of the film is extremely thin, for example, 20 nm or less.
  • the negative electrode layer 16 includes a negative electrode active material, and this negative electrode active material may be any of various known negative electrode active materials that can be used in an all-solid lithium battery.
  • the negative electrode active material include lithium metal, lithium alloy, carbonaceous material, lithium titanate (LTO) and the like.
  • the negative electrode layer 16 is formed by forming a thin film of lithium metal or a metal alloying with lithium on the negative electrode current collector 17 (copper foil or the like) by vacuum deposition, sputtering, CVD, or the like. It can be produced by forming a metal or metal layer that is alloyed with lithium.
  • a metal alloyed with lithium As a constituent material of the intermediate layer, a metal alloyed with lithium, an oxide-based material, or the like can be used. In this case, charge / discharge cycle characteristics can be improved.
  • metals alloyed with lithium include Al (aluminum), Si (silicon), Zn (zinc), Ga (gallium), Ge (germanium), Ag (silver), Au (gold), and Cd (cadmium). , In (indium), Sn (tin), Sb (antimony), Pb (lead), Bi (bismuth), and any combination thereof.
  • the metal alloyed with lithium may be an alloy composed of two or more elements such as Mg 2 Si and Mg 2 Sn.
  • the oxide material include Li 4 Ti 5 O 12 , TiO 2 , and SiO.
  • the intermediate layer may be formed by a known method such as an aerosol deposition (AD) method, a pulse laser deposition (PLD) method, or a sputtering method.
  • the positive electrode plate 12 and / or the negative electrode layer 16 are preferably provided with a positive electrode current collector 13 and / or a negative electrode current collector 17.
  • the positive electrode current collector 13 is provided on the surface of the positive electrode plate 12 opposite to the solid electrolyte layer 14, while the negative electrode current collector 17 is formed of the solid electrolyte layer of the negative electrode layer 16.
  • 14 is provided on the opposite side of the surface.
  • materials constituting the positive electrode current collector 13 and the negative electrode current collector 17 include platinum (Pt), platinum (Pt) / palladium (Pd), gold (Au), silver (Ag), aluminum (Al), Examples thereof include copper (Cu), ITO (indium-tin oxide film), and Ni (nickel).
  • the container 18 is not particularly limited as long as it can accommodate a unit battery or a stack in which a plurality of unit batteries are stacked in series or in parallel.
  • the container 18 can adopt a relatively simple container form.
  • a chip configuration for mounting on an electronic circuit for example, a laminate cell configuration for thin and wide space applications (for example, a multilayer product of aluminum (Al) / polypropylene (PP)), a resin mold configuration, a battery component in a metal plate
  • raw material particles particles of a compound such as Li, Co, Ni, Mn, and Al were appropriately mixed so that the composition after synthesis was a positive electrode active material LiMO 2 having a layered rock salt structure. Things are used. Alternatively, raw material particles having a composition of LiMO 2 (synthesized particles) can be used.
  • LiMO 2 is obtained by further reacting the fired molded body with the lithium compound after the firing process of the molded body.
  • raw material particles not containing lithium mixed particles ((Co, Ni, Mn) O x , (Co, Ni, Al) O x , (Co, Ni, Mn) of compounds such as Co, Ni, Mn, and Al are used. ) OH x , (Co, Ni, Al) OH x, etc.).
  • the at least one metal compound is an oxide, hydroxide and / or carbonate of at least one metal selected from the group consisting of Co, Ni, Mn and Al.
  • These particles may be in the form of a mixed powder of two or more kinds of metal compound particles, or may be particles made of a composite compound synthesized by a coprecipitation method.
  • a lithium compound may be added in an excess of 0.5 to 30 mol%.
  • 0.001 to 30 wt% of a low melting point oxide such as bismuth oxide or a low melting point glass such as borosilicate glass may be added.
  • the raw material particles are formed into a sheet-like self-supporting compact. That is, the “self-supporting molded body” typically can maintain the shape of a sheet-shaped molded body by itself. In addition, even if it alone can not keep the shape of the sheet-like molded body, it may be attached to any substrate or formed into a film and peeled off from this substrate before or after firing, Included in “self-supported compact”.
  • a doctor blade method using a slurry containing raw material particles can be used.
  • a drum dryer may be used for forming a formed body, in which a slurry containing a raw material is applied onto a heated drum and the dried material is scraped off with a scraper.
  • a disk drier can be used for forming the formed body, in which a slurry is applied to a heated disk surface, dried and scraped with a scraper.
  • the hollow granulated body obtained by setting the conditions of a spray dryer suitably can also be regarded as the sheet-like molded object with a curvature, it can be used suitably as a molded object.
  • an extrusion molding method using a clay containing raw material particles can also be used as a molding method of the molded body.
  • the slurry is applied to a flexible plate (for example, an organic polymer plate such as a PET film), and the applied slurry is dried and solidified to form a molded product, and the molded product and the plate are peeled off. By doing so, you may produce the molded object before baking of a plate-like polycrystalline particle.
  • a flexible plate for example, an organic polymer plate such as a PET film
  • inorganic particles may be dispersed in a suitable dispersion medium, and a binder, a plasticizer, or the like may be added as appropriate.
  • the slurry is preferably prepared so as to have a viscosity of 500 to 4000 cP, and is preferably degassed under reduced pressure.
  • the molded body obtained in the molding process is placed on a setter and fired, for example, in a molded state (a sheet state).
  • the firing step may be one in which a sheet-like formed body is appropriately cut and crushed and placed in a sheath and fired.
  • the raw material particles are mixed particles before synthesis, synthesis, further sintering and grain growth occur in this firing step.
  • a molded object is a sheet form
  • the grain growth of the thickness direction is restricted. For this reason, after the grains have grown until the number of crystal grains becomes one in the thickness direction of the compact, grain growth proceeds only in the in-plane direction of the compact. At this time, a specific crystal plane which is stable in terms of energy spreads on the sheet surface (plate surface). Therefore, a film-like sheet (self-supporting film) oriented such that a specific crystal plane is parallel to the sheet surface (plate surface) is obtained.
  • the (101) plane and (104) plane which are crystal planes in which lithium ions can enter and exit satisfactorily, can be oriented so as to be exposed on the sheet surface (plate surface).
  • the (h00) plane which becomes the (104) plane when reacted with a lithium compound to form LiMO 2 , It can be oriented so as to be exposed on the sheet surface (plate surface).
  • the firing temperature is preferably 700 ° C to 1350 ° C.
  • the firing time is preferably between 1 and 50 hours. If it is shorter than 1 hour, the degree of orientation becomes low. On the other hand, if it is longer than 50 hours, energy consumption becomes too large.
  • the firing atmosphere is appropriately set so that decomposition does not proceed during firing.
  • the volatilization of lithium proceeds, it is preferable to arrange lithium carbonate or the like in the same sheath to create a lithium atmosphere.
  • firing is preferably performed in an atmosphere having a high oxygen partial pressure.
  • a positive electrode active material film oriented so as to be exposed to the surface is obtained.
  • lithium is introduced by sprinkling the orientation sheet lithium nitrate so that the molar ratio Li / M of Li and M is 1 or more and heat-treating.
  • the heat treatment temperature is preferably 600 ° C. to 800 ° C. At a temperature lower than 600 ° C., the reaction does not proceed sufficiently. When the temperature is higher than 900 ° C., the orientation deteriorates.
  • Li p (Ni x, Co y , Al z) O 2 or Li p (Ni x, Co y , Mn z) positive electrode active material sheet using O 2 particles for example, be prepared in the following manner Good. First, a green sheet containing NiO powder, Co 3 O 4 powder, and AlOOH or Mn 3 O 4 powder is formed, and the green sheet is fired at a temperature within a range of 1000 ° C. to 1400 ° C. in an air atmosphere for a predetermined time.
  • an independent film-like sheet composed of a large number of (h00) -oriented (Ni, Co, Al) O or (Ni, Co, Mn) O particles is formed.
  • MnO 2 , ZnO or the like as an auxiliary agent, grain growth is promoted, and as a result, the (h00) orientation of the plate-like crystal grains can be enhanced.
  • the “independent” sheet refers to a sheet that can be handled by itself independently from another support after firing. That is, the “independent” sheet does not include a sheet that is fixed to another support (substrate or the like) by firing and integrated with the support (unseparable or difficult to separate).
  • the amount of the material existing in the thickness direction is very small compared to the plate surface direction, that is, the in-plane direction (direction orthogonal to the thickness direction). For this reason, in the initial stage where there are a plurality of grains in the thickness direction, grains grow in random directions.
  • the grain growth direction is limited to the in-plane two-dimensional direction. This reliably promotes grain growth in the surface direction. In particular, even if the thickness of the green sheet is relatively thick, such as about 100 ⁇ m or more, the grain growth in the plane direction is more surely promoted by promoting the grain growth as much as possible.
  • the grain growth in the plane direction of the grains parallel to the plate surface direction that is, the in-plane direction (direction orthogonal to the thickness direction) is promoted preferentially. Therefore, by firing the green sheet formed in a film shape as described above, a large number of thin plate-like particles oriented so that a specific crystal plane is parallel to the plate surface of the particles are formed at the grain boundary portion. A free-standing film bonded in the plane direction can be obtained. That is, a self-supporting film is formed so that the number of crystal grains in the thickness direction is substantially one.
  • the meaning of “substantially one crystal grain in the thickness direction” does not exclude that a part (for example, end portions) of crystal grains adjacent in the plane direction overlap each other in the thickness direction.
  • This self-supporting film can be a dense ceramic sheet in which a large number of thin plate-like particles as described above are bonded without gaps.
  • the (h00) -oriented (Ni, Co, Al) O or (Ni, Co, Mn) O ceramic sheet obtained by the above process is mixed with lithium nitrate (LiNO 3 ) and heated for a predetermined time. Thus, lithium is introduced into the (Ni, Co, Al) O or (Ni, Co, Mn) O particles.
  • the (003) plane is oriented in the direction from the positive electrode plate 12 to the negative electrode layer 16, and the (104) plane is oriented along the plate surface for Li p (Ni x , Co y , Mn z) O 2 sheet or Li p (Ni x, Co y , Al z) O 2 sheet is obtained.
  • a raw material containing a Li component, a La component and a Zr component is fired to obtain a primary fired powder for ceramic synthesis containing Li, La, Zr and oxygen.
  • the primary fired powder obtained in the first firing step is fired to synthesize a ceramic having a garnet-type or garnet-like crystal structure containing Li, La, Zr, and oxygen.
  • Li component, La component and Zr component These various components are not particularly limited, and various metal salts such as metal oxides, metal hydroxides, and metal carbonates containing the respective metal components can be appropriately selected and used.
  • Li 2 CO 3 or LiOH can be used as the Li component
  • La (OH) 3 or La 2 O 3 can be used as the La component
  • ZrO 2 can be used as the Zr component.
  • oxygen is usually included as an element constituting a part of a compound containing these constituent metal elements.
  • the raw material for obtaining the ceramic material can contain a Li component, a La component, and a Zr component to such an extent that an LLZ crystal structure can be obtained from each Li component, La component, Zr component, and the like by a solid phase reaction or the like.
  • the Li component, La component and Zr component can be used in a composition close to 7: 3: 2 or a composition ratio.
  • the Li component includes an amount increased by about 10% from the molar ratio equivalent amount based on the stoichiometry of Li in LLZ, and the La component and the Zr component are each in an LLZ molar ratio. It can contain so that it may become the quantity equivalent to.
  • the molar ratio of Li: La: Zr is 7.7: 3: 2.
  • the molar ratio is about 3.85: about 3: about 2 when Li 2 CO 3 : La (OH) 3 : ZrO 2 , and Li 2 CO 3 :
  • the molar ratio is about 3.85: about 1.5: about 2
  • LiOH: La (OH) 3 : ZrO 2 is about 7.7: about 3: about 2.
  • LiOH: La 2 O 3 : ZrO 2 it is about 7.7: about 1.5: about 2.
  • a known raw material powder preparation method in the synthesis of ceramic powder can be appropriately employed.
  • the mixture can be mixed uniformly by putting it into a reiki machine or a suitable ball mill.
  • the first firing step is a step of obtaining a primary fired powder for facilitating the thermal decomposition of at least the Li component and the La component to easily form the LLZ crystal structure in the second firing step.
  • the primary fired powder may already have an LLZ crystal structure.
  • the firing temperature is preferably 850 ° C. or higher and 1150 ° C. or lower.
  • the first baking step may include a step of heating at a lower heating temperature and a step of heating at a higher heating temperature within the above temperature range. By providing such a heating step, a more uniform ceramic powder can be obtained, and a high-quality sintered body can be obtained by the second firing step.
  • the heat treatment step constituting the first firing step is preferably performed by a heat treatment step of 850 ° C. or more and 950 ° C. or less and a heat treatment step of 1075 ° C. or more and 1150 ° C. or less. More preferably, a heat treatment step of 875 ° C. to 925 ° C.
  • the first baking step the total heating time at the maximum temperature set as the heating temperature as a whole is preferably about 10 hours to 15 hours. In the case where the first baking step is composed of two heat treatment steps, it is preferable that the heating time at the maximum temperature is about 5 to 6 hours.
  • the first firing step can be shortened by changing one or more components of the starting material.
  • an LLZ component containing Li, La and Zr is heated at a maximum temperature in a heat treatment step of 850 ° C. or more and 950 ° C. or less.
  • the heating time can be 10 hours or less. This is because LiOH used as a starting material forms a liquid phase at a low temperature, and thus easily reacts with other components at a lower temperature.
  • a 2nd baking process can be made into the process of heating the primary baking powder obtained at the 1st baking process at the temperature of 950 degreeC or more and 1250 degrees C or less.
  • the primary firing powder obtained in the first firing step is fired, and finally a ceramic having an LLZ crystal structure that is a composite oxide can be obtained.
  • an LLZ component including Li, La, and Zr is heat-treated at a temperature of 1125 ° C. or higher and 1250 ° C. or lower.
  • Li 2 CO 3 is used as the Li raw material, it is preferable to perform heat treatment at 1125 ° C. or higher and 1250 ° C. or lower.
  • the temperature of the second firing step can be lowered by changing one or more components of the starting material.
  • an LLZ constituent component including Li, La, and Zr can be heat-treated at a temperature of 950 ° C. or higher and lower than 1125 ° C. This is because LiOH used as a starting material forms a liquid phase at a low temperature, and thus easily reacts with other components at a lower temperature.
  • the heating time at the heating temperature in the second firing step is preferably about 18 hours or more and 50 hours or less. When the time is shorter than 18 hours, the formation of the LLZ ceramics is not sufficient.
  • the primary fired powder is pressure-molded using a well-known pressing technique to give a desired three-dimensional shape (for example, a shape and size that can be used as a solid electrolyte of an all-solid lithium battery). It is preferable to implement the above. By using a molded body, a solid phase reaction is promoted and a sintered body can be obtained.
  • the molded body containing the primary fired powder is fired and sintered in the second firing step, it is preferable to carry out the process so that the molded body is buried in the same powder. By doing so, the loss of Li can be suppressed and the change in composition before and after the second firing step can be suppressed.
  • the molded body of the raw material powder is usually buried in the raw material powder in a state where the raw material powder is spread and placed. By carrying out like this, reaction with a setter can be suppressed.
  • the curvature at the time of baking of a sintered compact can be prevented by pressing a molded object with a setter from the upper and lower sides of a filling powder as needed.
  • the primary fired powder compact can be sintered without being embedded in the same powder. This is because the loss of Li is relatively suppressed and the reaction with the setter can be suppressed by lowering the temperature of the second baking step.
  • the solid electrolyte layer 14 having the LLZ crystal structure can be obtained by using the powder that has undergone the above baking process.
  • the solid electrolyte layer having a crystal structure and containing aluminum is obtained by carrying out either or both of the first firing step and the second firing step in the presence of an aluminum (Al) -containing compound. You may make it manufacture.
  • the positive electrode plate was polished with a cross-section polisher (CP) so that the cross-section polished surface could be observed, and a cross-sectional image was obtained with an SEM (scanning microscope) (JSM-6390LA, manufactured by JEOL Ltd.). The thickness of the positive electrode plate was determined based on the obtained cross-sectional image.
  • CP cross-section polisher
  • SEM scanning microscope
  • ⁇ Relative density> The volume was calculated based on the size and thickness of the positive electrode plate. The weight of the positive electrode plate was measured, and the density was calculated by dividing this weight by the above volume. A relative density was obtained by dividing this density by the true density (theoretical density) of the substance constituting the positive electrode plate.
  • the plate surface of the positive electrode plate is used as a sample surface, and an XRD apparatus (manufactured by Rigaku Corporation, TTR-III) is used. It was performed under the condition of °.
  • the degree of orientation of the obtained XRD profile was calculated based on the following formula according to the Lotgering method.
  • I is the diffraction intensity of the positive electrode plate sample
  • I 0 is the diffraction intensity of a non-oriented reference sample (a non-oriented state obtained by pulverizing the positive electrode plate sample with a mortar) (HKL).
  • ⁇ Surface roughness Ra> Using a laser microscope (OLS4000, manufactured by Olympus Corporation), the surface roughness of the surface of the positive electrode plate joined to the solid electrolyte layer is measured in the range of 130 ⁇ m ⁇ 130 ⁇ m, and the arithmetic average of the positive electrode plate surface The roughness Ra was determined.
  • ⁇ Rise rate of resistance value> The produced battery was subjected to AC impedance measurement at a frequency of 1 MHz to 0.1 Hz and a voltage of 10 mV using a Solartron electrochemical measurement system (potentiometer / galvano stud-frequency response analyzer), and the resistance value of the obtained battery was measured.
  • a Solartron electrochemical measurement system potentiometer / galvano stud-frequency response analyzer
  • this battery was charged with a constant current at a current value of 0.05 C rate until the battery voltage reached 4.3V. Thereafter, constant voltage charging was performed until the current value decreased to 1/20 under the current condition of maintaining the battery voltage at 4.3V.
  • the battery After resting for 10 minutes, the battery was discharged at a constant current at a current value of 0.05 C until the battery voltage reached 2.5 V, and then rested for 10 minutes. These charging / discharging operations were set as 1 cycle, and after repeating a total of 3 cycles on 25 degreeC conditions, alternating current impedance measurement was performed again. By dividing the resistance value after charging / discharging by the resistance value before charging / discharging, the increase rate of the resistance value was obtained.
  • a dispersion medium a mixed solvent containing toluene and isopropanol at a weight ratio of 1: 1
  • a binder polyvinyl butyral, BM-2, manufactured by Sekisui Chemical Co., Ltd.
  • a plasticizer DOP (di (2-ethylhexyl) phthalate), manufactured by Kurokin Kasei Co., Ltd.
  • a dispersant Rosidol SP-O30, manufactured by Kao Corporation
  • the slurry prepared as described above was formed into a sheet shape on a PET film by a doctor blade method so that the thickness after drying was 60 ⁇ m.
  • the obtained sheet was peeled off from the PET film and cut to 2 cm ⁇ 2 cm. 400 layers of the cut sheets were laminated and pre-pressed at 120 ° C. with a laminator to obtain a green bulk.
  • the obtained green bulk was heated to 600 ° C. at 20 ° C./h, held for 60 hours, and degreased by lowering the temperature at 20 ° C./h.
  • the obtained degreased bulk was vacuum packed and then pressed with CIP at a predetermined pressing pressure (for example, 3 t).
  • the obtained degreased bulk was heated up to a predetermined firing temperature (for example, 875 ° C.) at 100 ° C./h in an air atmosphere and held for 20 hours.
  • the obtained sintered bulk was cut out by processing so that the cross-sectional direction was the plate surface, and the positive electrode plate was obtained by polishing the surface of the plate surface.
  • the obtained positive electrode plate was bonded to an Al foil as a current collector with a conductive epoxy adhesive containing carbon.
  • thickness, relative density, orientation degree, and surface roughness Ra were measured by the method mentioned above. The results are shown in Table 1.
  • the positive electrode plates produced in Examples 1 to 21 have various thicknesses, relative densities, orientation degrees, and surface roughness Ra, which are arbitrarily given by appropriately adjusting the production conditions.
  • the degree of orientation and the relative density were controlled by appropriately adjusting the pulverization time of the raw material, the firing temperature, and the pressure during molding).
  • the firing raw material was placed in an alumina crucible, heated at 600 ° C./hour in the air atmosphere, and held at 900 ° C. for 6 hours.
  • ⁇ -Al 2 O 3 is added to the powder obtained in the first firing step so as to have a concentration of 0.6% by mass, and this powder and cobblestone are mixed to form a vibration mill. And pulverized for 3 hours to obtain a powder having a starting material composition of Li 7.0 La 3.0 Zr 1.625 Ta 0.375 O 12 Al 0.1 .
  • the amount of ⁇ -Al 2 O 3 added is such that the compositional formula Li 7.0 La 3.0 Zr 1.625 Ta 0.375 assumes that the primary fired powder has a composition as charged.
  • the obtained raw material powder was put in a magnesia sheath and heat-treated at 800 ° C. for 1 hour in an Ar atmosphere to remove CO 2 and H 2 O that can be contained in the raw material powder.
  • the charged composition of Li 7.0 La 3.0 Zr It has a composition generally based on 1.625 Ta 0.375 O 12 Al 0.1 and does not contain lithium carbonate.
  • the raw material powder after the heat treatment was crushed in a glove box under an Ar atmosphere using a nylon mesh having an opening diameter of 75 ⁇ m, and then deposited by an aerosol deposition (AD) method using N 2 gas as a carrier gas. .
  • This AD film formation was performed using a film formation apparatus 20 as shown in FIG.
  • a film forming apparatus 20 shown in FIG. 2 is configured as an apparatus used for the AD method in which a raw material powder is injected onto a substrate in an atmosphere at a pressure lower than atmospheric pressure.
  • the film forming apparatus 20 includes an aerosol generating unit 22 that generates an aerosol of a raw material powder containing a raw material component, and a film forming unit 30 that sprays the raw material powder onto a substrate 21 to form a film containing the raw material component.
  • the aerosol generation unit 22 contains a raw material powder, receives an supply of a carrier gas from a gas cylinder (not shown), generates an aerosol, a raw material supply pipe 24 that supplies the generated aerosol to the film forming unit 30, and An aerosol generation chamber 23 and a vibrator 25 for applying vibration to the aerosol in the chamber at a frequency of 10 to 100 Hz are provided.
  • the film forming unit 30 includes a film forming chamber 32 for injecting aerosol onto the substrate 21, a substrate holder 34 disposed in the film forming chamber 32 for fixing the substrate 21, and the substrate holder 34 in the X-axis-Y-axis directions. And an XY stage 33 that moves.
  • the film forming unit 30 includes a spray nozzle 36 that has a slit 37 formed at the tip thereof and sprays aerosol onto the substrate 21, and a vacuum pump 38 that decompresses the film forming chamber 32.
  • the film forming apparatus 20 may be configured to heat the raw material powder by providing a heating device, a heat-resistant member, or the like in the film forming chamber 32.
  • a heat-resistant member such as quartz glass or ceramics may be used so that heat treatment can be performed at a temperature at which the raw material powder is single-crystallized.
  • the production conditions of the solid electrolyte membrane by the film forming apparatus 20 were as follows. As the substrate, the previously synthesized positive electrode plate was used.
  • oxygen gas having a flow rate of 2 L / min is used as a carrier gas, and the pressure in the deposition chamber is adjusted to 0.1 to 0.2 kPa and the pressure in the aerosol chamber is adjusted to 50 to 70 kPa. Went.
  • the opening size of the nozzle was set to 10 mm ⁇ 1.8 mm, and scanning was performed simultaneously with the film formation for 60 reciprocations at a scanning distance of 10 mm and a scanning speed of 5 mm / sec in the short side direction of the nozzle. In this way, a Li—La—Zr—O-based solid electrolyte AD film having a thickness of 2 ⁇ m was formed on the positive electrode plate.
  • nickel-cobalt composite hydroxide powder As the raw material powder, nickel-cobalt composite hydroxide having a composition of (Ni x Co y ) (OH) 2 so as to have the molar ratio shown in Table 1 Example 1 except that a mixed powder obtained by weighing powder and AlOOH (made by SASOL) was used, and that the degreasing bulk was fired by holding at 775 ° C. for 20 hours in an oxygen atmosphere. All-solid lithium batteries were prepared and evaluated in the same basic procedure as in -21. The nickel / cobalt composite hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 1.
  • Examples 26-28 All solid lithium was obtained by the same basic procedure as in Examples 1 to 21 except that cobalt hydroxide (Co (OH) 2 ) powder was used instead of nickel / cobalt / manganese composite hydroxide powder as raw material powder. Battery preparation and various evaluations were performed. The cobalt hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 1.
  • Co (OH) 2 cobalt hydroxide
  • Examples 29-34 The same basic procedure as in Examples 1 to 21, except that a LiPON-based solid electrolyte sputtered film was prepared as follows instead of the Li-La-Zr-O-based solid electrolyte AD film as the solid electrolyte layer. An all-solid lithium battery was prepared and subjected to various evaluations. The results were as shown in Table 2.
  • LiPON-based solid electrolyte sputtered film A lithium phosphate sintered compact target having a diameter of 4 inches (about 10 cm) was prepared. Using this target, sputtering was performed using a sputtering apparatus (SPF-430H, manufactured by Canon Anelva) with an RF magnetron method so that the gas type N 2 was 0.2 Pa, the output was 0.2 kW, and the film thickness was 1 ⁇ m. . Thus, a LiPON-based solid electrolyte sputtered film having a thickness of 1 ⁇ m was formed on the positive electrode plate.
  • SPPF-430H sputtering apparatus
  • Example 35 Instead of using nickel-cobalt-manganese composite hydroxide powder as a raw material powder, nickel-cobalt composite hydroxide having a composition of (Ni x Co y ) (OH) 2 so as to have a molar ratio shown in Table 2 Example 29, except that a mixed powder obtained by weighing powder and AlOOH (manufactured by SASOL) was used, and that the degreasing bulk was fired by holding at 775 ° C. for 20 hours in an oxygen atmosphere. All-solid lithium batteries were prepared and evaluated in the same basic procedure as in .about.34. The nickel / cobalt composite hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 2.
  • Example 36 All solid lithium was prepared in the same basic procedure as in Examples 29 to 34 except that cobalt hydroxide (Co (OH) 2 ) powder was used instead of nickel / cobalt / manganese composite hydroxide powder as raw material powder. Battery preparation and various evaluations were performed. The cobalt hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 2.

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Abstract

　To provide an all-solid-state lithium cell having a configuration in which capacitance and energy density are suitably improved, it being possible to significantly reduce the deterioration in cell characteristics (particularly the rise in the resistance value) that follows repeated charging and discharging. This all-solid-state lithium cell is provided with: a positive electrode plate comprising an oriented polycrystal that comprises a plurality of lithium transition metal oxide particles having a lamellar rocksalt structure with a basic composition represented by Lip(Nix,Coy,Mnz)O2 (where 0.9≤p≤1.3, 0<x<0.8, 0<y<1, 0≤z≤0.7, and x+y+z=1) or Lip(Nix,Coy,Alz)O2 (where 0.9≤p≤1.3, 0.6<x<0.9, 0.1<y≤0.3, 0≤z≤0.2, and x+y+z=1); a solid-state electrolyte layer configured using a Li-La-Zr-O-based ceramic material and/or a lithium phosphorus oxynitride (LiPON)-based ceramic material; and a negative electrode layer. The oriented polycrystal has a thickness of 10 µm or more and a degree of orientation of 15-85%.

Description

全固体リチウム電池All solid lithium battery
　本発明は、全固体リチウム電池に関するものである。 The present invention relates to an all solid lithium battery.
　近年、パーソナルコンピュータ、携帯電話等のポータブル機器の開発に伴い、その電源としての電池の需要が大幅に拡大している。このような用途に用いられる電池においては、イオンを移動させる媒体として、希釈溶媒に可燃性の有機溶媒を用いた有機溶媒等の液体の電解質（電解液）が従来使用されている。このような電解液を用いた電池においては、電解液の漏液や、発火、爆発等の問題を生ずる可能性がある。 In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries as the power source has greatly increased. In a battery used for such an application, a liquid electrolyte (electrolytic solution) such as an organic solvent using a flammable organic solvent as a diluent solvent has been conventionally used as a medium for moving ions. A battery using such an electrolytic solution may cause problems such as leakage of the electrolytic solution, ignition, and explosion.
　このような問題を解消すべく、本質的な安全性確保のために、液体の電解質に代えて固体電解質を使用するとともに、その他の要素の全てを固体で構成した全固体電池の開発が進められている。このような全固体電池は、電解質が固体であることから、発火の心配が少なく、漏液せず、また、腐食による電池性能の劣化等の問題も生じ難い。 In order to solve these problems, in order to ensure intrinsic safety, development of an all-solid-state battery in which a solid electrolyte is used instead of a liquid electrolyte and all other elements are made of solid is being promoted. ing. Such an all-solid battery has a solid electrolyte, so there is little fear of ignition, no leakage, and problems such as deterioration of battery performance due to corrosion hardly occur.
　例えば、特許文献１（特開２０１３－１０５７０８号公報）には、コバルト酸リチウム（ＬｉＣｏＯ２）からなる正極層と、金属リチウムからなる負極層と、リン酸リチウムオキシナイトライドガラス電解質（ＬＩＰＯＮ）で形成されうる固体電解質層とを備えた薄膜リチウム二次電池が開示されており、正極層がスパッタリングにより形成され、その厚さは１～１５μｍの範囲であることが記載されている。また、正極をより厚くして容量の向上を試みた全固体電池も提案されている。例えば、特許文献２（特表２００９－５１６３５９号公報）には、厚さが約４μｍより大きく約２００μｍ未満の正極と、厚さ約１０μｍ未満の固体電解質と、厚さ約３０μｍ未満の負極とを有する全固体電池が開示されている。これらの文献には正極活物質を配向させたとの記載は見受けられない。 For example, Patent Document 1 (Japanese Patent Laid-Open No. 2013-105708) describes a positive electrode layer made of lithium cobaltate (LiCoO 2 ), a negative electrode layer made of metallic lithium, and a lithium phosphate oxynitride glass electrolyte (LIPON). A thin-film lithium secondary battery including a solid electrolyte layer that can be formed is disclosed, and it is described that a positive electrode layer is formed by sputtering and has a thickness in the range of 1 to 15 μm. In addition, an all-solid battery has been proposed in which the positive electrode is made thicker to try to improve the capacity. For example, Patent Document 2 (Japanese Patent Publication No. 2009-516359) discloses a positive electrode having a thickness greater than about 4 μm and less than about 200 μm, a solid electrolyte having a thickness of less than about 10 μm, and a negative electrode having a thickness of less than about 30 μm. An all-solid battery is disclosed. In these documents, there is no description that the positive electrode active material is oriented.
　一方、リチウム複合酸化物の配向焼結体板が提案されている。例えば、特許文献３（特開２０１２－００９１９３号公報）及び特許文献４（特開２０１２－００９１９４号公報）には、層状岩塩構造を有し、Ｘ線回折における、（１０４）面による回折強度に対する（００３）面による回折強度の比率［００３］／［１０４］が２以下である、リチウム複合酸化物焼結体板が開示されている。また、特許文献５（特許第４７４５４６３号公報）には、一般式：Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０．６＜ｘ≦０．９、０．１＜ｙ≦０．３、０≦ｚ≦０．２、ｘ＋ｙ＋ｚ＝１）で表され、層状岩塩構造を有する板状粒子が開示されており、（００３）面が粒子の板面と交差するように配向されることが記載されている。 On the other hand, an oriented sintered body plate of a lithium composite oxide has been proposed. For example, Patent Document 3 (Japanese Patent Laid-Open No. 2012-009193) and Patent Document 4 (Japanese Patent Laid-Open No. 2012-009194) have a layered rock salt structure, and have X-ray diffraction with respect to the diffraction intensity by the (104) plane. A lithium composite oxide sintered plate having a diffraction intensity ratio [003] / [104] of (003) plane of 2 or less is disclosed. Patent Document 5 (Japanese Patent No. 4745463) discloses a general formula: Li p (Ni x , Co y , Al z ) O 2 (where 0.9 ≦ p ≦ 1.3, 0.6 < x ≦ 0.9, 0.1 <y ≦ 0.3, 0 ≦ z ≦ 0.2, x + y + z = 1) and a plate-like particle having a layered rock salt structure is disclosed, and (003) plane Is oriented so as to intersect the plate surface of the particles.
　また、リチウムイオン伝導性を有する固体電解質として、Ｌｉ７Ｌａ３Ｚｒ２Ｏ１２に代表されるＬｉ－Ｌａ－Ｚｒ－Ｏ系複合酸化物（以下、ＬＬＺという）の組成を有するガーネット型のセラミックス材料が注目されている。例えば、特許文献６（特開２０１１－０５１８００号公報）には、ＬＬＺの基本元素であるＬｉ，Ｌａ及びＺｒに加えてＡｌを加えることで、緻密性やリチウムイオン伝導率を向上できることが開示されている。特許文献７（特開２０１１－０７３９６２号公報）には、ＬＬＺの基本元素であるＬｉ、Ｌａ及びＺｒに加えてＮｂ及び／又はＴａを加えることで、リチウムイオン伝導率を更に向上できることが開示されている。特許文献８（特開２０１１－０７３９６３号公報）には、Ｌｉ、Ｌａ、Ｚｒ及びＡｌを含み、Ｌａに対するＬｉのモル比を２．０～２．５とすることで、緻密性を更に向上できることが開示されている。 Further, as a solid electrolyte having lithium ion conductivity, a garnet-type ceramic material having a composition of Li—La—Zr—O based composite oxide (hereinafter referred to as LLZ) represented by Li 7 La 3 Zr 2 O 12 Is attracting attention. For example, Patent Document 6 (Japanese Patent Laid-Open No. 2011-051800) discloses that the addition of Al in addition to Li, La, and Zr, which are basic elements of LLZ, can improve the density and lithium ion conductivity. ing. Patent Document 7 (Japanese Patent Application Laid-Open No. 2011-073962) discloses that lithium ion conductivity can be further improved by adding Nb and / or Ta in addition to Li, La and Zr, which are basic elements of LLZ. ing. Patent Document 8 (Japanese Patent Laid-Open No. 2011-073963) includes Li, La, Zr, and Al, and the density can be further improved by setting the molar ratio of Li to La to 2.0 to 2.5. Is disclosed.
特開２０１３－１０５７０８号公報JP 2013-105708 A 特表２００９－５１６３５９号公報Special table 2009-516359 gazette 特開２０１２－００９１９３号公報JP 2012-009193 A 特開２０１２－００９１９４号公報JP 2012-009194 A 特許第４７４５４６３号公報Japanese Patent No. 4745463 特開２０１１－０５１８００号公報JP 2011-051800 A 特開２０１１－０７３９６２号公報JP 2011-073962 A 特開２０１１－０７３９６３号公報JP 2011-073963 A
　本発明者らは、今般、全固体リチウム電池において、特定組成の配向性を有する正極板と特定組成の固体電解質層とを組み合わせ、なおかつ正極板の厚さ及び配向度を所定範囲内に制御することで、容量及びエネルギー密度の向上に適した構成でありながら、充放電の繰り返しに伴う電池特性の劣化（特に抵抗値の上昇）を有意に低減できるとの知見を得た。 In the all-solid lithium battery, the present inventors now combine a positive electrode plate having a specific composition with a solid electrolyte layer having a specific composition, and control the thickness and degree of orientation of the positive electrode plate within a predetermined range. As a result, the present inventors have found that although the configuration is suitable for improving the capacity and energy density, deterioration of battery characteristics (particularly, increase in resistance value) due to repeated charge / discharge can be significantly reduced.
　したがって、本発明の目的は、容量及びエネルギー密度の向上に適した構成でありながら、充放電の繰り返しに伴う電池特性の劣化（特に抵抗値の上昇）を有意に低減できる全固体リチウム電池を提供することにある。 Accordingly, an object of the present invention is to provide an all-solid-state lithium battery that can significantly reduce deterioration of battery characteristics (particularly increase in resistance value) due to repeated charge and discharge, while having a configuration suitable for improving capacity and energy density. There is to do.
　本発明の一態様によれば、１０μｍ以上の厚さ及び１５～８５％の配向度を有する配向多結晶体からなる正極板であって、該配向多結晶体が、Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０≦ｘ＜０．８、０≦ｙ＜１、０≦ｚ≦０．７、ｘ＋ｙ＋ｚ＝１）又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０．６＜ｘ＜０．９、０．１＜ｙ≦０．３、０≦ｚ≦０．２、ｘ＋ｙ＋ｚ＝１）で表される基本組成の層状岩塩構造を有する複数のリチウム遷移金属酸化物粒子からなる、正極板と、
　前記正極板上に設けられ、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系セラミックス材料及び／又はリン酸リチウムオキシナイトライド（ＬｉＰＯＮ）系セラミックス材料で構成される固体電解質層と、
　前記固体電解質層上に設けられる負極層と、
を備えた、全固体リチウム電池が提供される。 According to one embodiment of the present invention, there is provided a positive electrode plate made of an oriented polycrystal having a thickness of 10 μm or more and an orientation degree of 15 to 85%, wherein the oriented polycrystal is Li p (Ni x , Co y 1 , Mn z ) O 2 (where 0.9 ≦ p ≦ 1.3, 0 ≦ x <0.8, 0 ≦ y <1, 0 ≦ z ≦ 0.7, x + y + z = 1) or Li p (Ni x , Co y , Al z ) O 2 (wherein 0.9 ≦ p ≦ 1.3, 0.6 <x <0.9, 0.1 <y ≦ 0.3, 0 ≦ z ≦ A positive electrode plate comprising a plurality of lithium transition metal oxide particles having a layered rock salt structure having a basic composition represented by 0.2, x + y + z = 1);
A solid electrolyte layer provided on the positive electrode plate and composed of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material;
A negative electrode layer provided on the solid electrolyte layer;
An all-solid lithium battery is provided.
本発明の全固体リチウム電池の一例を示す模式断面図である。It is a schematic cross section which shows an example of the all-solid-state lithium battery of this invention. 実施例で用いたエアロゾルデポジション（ＡＤ）成膜装置の構成を示す概略模式図である。It is a schematic diagram which shows the structure of the aerosol deposition (AD) film-forming apparatus used in the Example.
　全固体リチウム電池
　図１に本発明による全固体リチウム電池の一例を模式的に示す。図１に示される全固体リチウム電池１０は、正極板１２と、正極板１２上に設けられる固体電解質層１４と、固体電解質層１４上に設けられる負極層１６とを備えてなる。正極板１２は、１０μｍ以上の厚さ及び１５～８５％の配向度を有する配向多結晶体からなる。そして、この配向多結晶体は、Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０≦ｘ＜０．８、０≦ｙ＜１、０≦ｚ≦０．７、ｘ＋ｙ＋ｚ＝１）又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０．６＜ｘ＜０．９、０．１＜ｙ≦０．３、０≦ｚ≦０．２、ｘ＋ｙ＋ｚ＝１）で表される基本組成の層状岩塩構造を有する複数のリチウム遷移金属酸化物粒子からなる。固体電解質層１４は、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系セラミックス材料及び／又はリン酸リチウムオキシナイトライド（ＬｉＰＯＮ）系セラミックス材料で構成される。このような構成の全固体リチウム電池によれば、容量及びエネルギー密度の向上に適した構成でありながら、充放電の繰り返しに伴う電池特性の劣化（特に抵抗値の上昇）を有意に低減することができる。 An example of the all-solid lithium battery according to the invention is shown schematically in all-solid-state lithium batteries Figure 1. An all solid lithium battery 10 shown in FIG. 1 includes a positive electrode plate 12, a solid electrolyte layer 14 provided on the positive electrode plate 12, and a negative electrode layer 16 provided on the solid electrolyte layer 14. The positive electrode plate 12 is made of an oriented polycrystal having a thickness of 10 μm or more and an orientation degree of 15 to 85%. And this oriented polycrystal is Li p (Ni x , Co y , Mn z ) O 2 (wherein 0.9 ≦ p ≦ 1.3, 0 ≦ x <0.8, 0 ≦ y <1) , 0 ≦ z ≦ 0.7, x + y + z = 1) or Li p (Ni x , Co y , Al z ) O 2 (where 0.9 ≦ p ≦ 1.3, 0.6 <x <0. 9, 0.1 <y ≦ 0.3, 0 ≦ z ≦ 0.2, x + y + z = 1), and a plurality of lithium transition metal oxide particles having a layered rock salt structure having a basic composition represented by: The solid electrolyte layer 14 is made of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material. According to the all-solid-state lithium battery having such a configuration, although it is a configuration suitable for improving the capacity and energy density, the deterioration of battery characteristics (particularly the increase in resistance value) due to repeated charge and discharge is significantly reduced. Can do.
　正極板１２及び固体電解質層１４の各組成は、例えば特許文献３～８で述べられるように、電池特性の向上をもたらすことが知られたものではあるが、本発明にあっては、正極板１２を配向多結晶体で構成し、なおかつその厚さを１０μｍ以上と厚くする。この点、特許文献１及び２のように配向を狙うことなく厚さ１０μｍ以上にした正極層は知られているが、正極層を単に厚く形成しただけでは、期待したほど容量及びエネルギー密度の増加が得られない。これは、正極活物質が配向されていない従来型の正極層の場合、厚い正極層の厚さ全体にわたった高効率なリチウムイオンの脱挿入がしづらいためであると考えられる。例えば、厚い正極層の固体電解質から離れた側に存在するリチウムを十分に取り出せないことが起こりうる。この点、本発明に用いる正極板１２は一定の方向に配向された複数のリチウム遷移金属酸化物粒子からなる配向多結晶体であるため、正極活物質を厚く設けても、正極層の厚さ全体にわたった高効率なリチウムイオンの脱挿入がしやすく、厚い正極活物質によってもたらされる容量向上効果を最大限に引き出すことができる。例えば、厚い正極層の固体電解質から離れた側に存在するリチウムも十分に取り出すことができる。かかる容量の向上によって、全固体電池のエネルギー密度をも大いに向上することができる。すなわち、本発明の全固体リチウム電池によれば、容量及びエネルギー密度の高い電池性能が得られる。したがって、比較的薄型ないし小型でありながらも、高い容量と高いエネルギー密度を有する安全性が高い全固体電池を実現することができる。特に、正極板１２はセラミックス焼結体で構成できるため、スパッタリング等の気相法により形成される膜と比べて厚く形成しやすいとともに、原料粉末の秤量を厳密に行うことで組成を正確に制御しやすいとの利点もある。 Each composition of the positive electrode plate 12 and the solid electrolyte layer 14 is known to improve battery characteristics as described in Patent Documents 3 to 8, for example. In the present invention, the positive electrode plate 12 is made of an oriented polycrystal and the thickness is increased to 10 μm or more. In this regard, a positive electrode layer having a thickness of 10 μm or more is not known as in Patent Documents 1 and 2, but the capacity and energy density are increased as expected only by forming the positive electrode layer to be thick. Cannot be obtained. This is considered to be because, in the case of a conventional positive electrode layer in which the positive electrode active material is not oriented, it is difficult to efficiently remove and insert lithium ions over the entire thickness of the thick positive electrode layer. For example, it may happen that lithium existing on the side of the thick positive electrode layer away from the solid electrolyte cannot be sufficiently extracted. In this respect, since the positive electrode plate 12 used in the present invention is an oriented polycrystal composed of a plurality of lithium transition metal oxide particles oriented in a certain direction, the thickness of the positive electrode layer can be increased even if a thick positive electrode active material is provided. It is easy to remove and insert high-efficiency lithium ions throughout, and the capacity improvement effect brought about by the thick positive electrode active material can be maximized. For example, lithium existing on the side of the thick positive electrode layer away from the solid electrolyte can be sufficiently extracted. Such an increase in capacity can greatly improve the energy density of the all-solid-state battery. That is, according to the all solid lithium battery of the present invention, battery performance with high capacity and energy density can be obtained. Therefore, it is possible to realize a highly safe all-solid battery having a high capacity and a high energy density while being relatively thin or small. In particular, since the positive electrode plate 12 can be composed of a ceramic sintered body, it can be easily formed thicker than a film formed by a vapor phase method such as sputtering, and the composition is accurately controlled by strictly weighing the raw material powder. There is also an advantage that it is easy to do.
　しかしながら、上記のように望ましい正極板１２及び固体電解質層１４の組合せでありながら、充放電を繰り返すにつれて電池特性が劣化（特に抵抗値の上昇）しうるとの問題が今般判明した。特に、上述した理論に照らせば正極板１２の配向度は高ければ高いほど電池特性を向上できるものと期待されたが、実際には、充放電の繰り返しに伴い電池の抵抗値が上昇してしまい、電池特性の劣化が起こりうる。これは、上記特定組成の厚い配向正極板を、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系及び／又はＬｉＰＯＮ系セラミックス材料からなる固体電解質に接合した場合に特に見られる現象である（例えば硫黄系の固体電解質材料からなる固体電解質に接合した場合には上記現象は見られない）。この点、本発明によれば、正極板１２を構成する配向多結晶体の配向度を１５～８５％に制御することで上述した電池の抵抗値の上昇を有意に低減することができる。この有利な効果をもたらすメカニズムは必ずしも定かではないが、充放電に伴うリチウムイオンの脱挿入による正極板１２の膨張収縮が上記配向度範囲内において低く抑えられることで、（厚いが故に本来大きくなりがちな）正極板１２内の応力が小さく抑えられ、その結果、正極板１２と固体電解質層１４との間で歪の少ない良好な界面状態（例えば剥離が無い等）を維持できるためではないかと推察される。すなわち、正極板１２と固体電解質層１４との間の界面における抵抗上昇が低減されるのではないかと考えられる。加えて、本発明者らの知見によれば、この低い膨張収縮率は正極板１２の組成とも相関関係があり、それ故１５～８５％との配向度範囲は上述した正極板の組成に特有の数値範囲であるものと解される（例えば正極板をＬｉＣｏＯ２で構成した場合には上記低い膨張収縮率は実現されない）。もっとも、本発明による上記効果をもたらす他の要因も可能性としてはありうることから、発明は上記理論に限定されて解釈されるべきではない。 However, it has now been found that the battery characteristics can be deteriorated (especially the resistance value is increased) as charging and discharging are repeated, although the combination of the positive electrode plate 12 and the solid electrolyte layer 14 is desirable as described above. In particular, according to the theory described above, it was expected that the higher the degree of orientation of the positive electrode plate 12, the better the battery characteristics could be improved. However, the battery resistance actually increased with repeated charge and discharge. Deterioration of battery characteristics can occur. This is a phenomenon particularly seen when a thick oriented positive electrode plate having the above specific composition is joined to a solid electrolyte made of a Li—La—Zr—O-based and / or LiPON-based ceramic material (for example, a sulfur-based solid electrolyte). The above phenomenon is not observed when bonded to a solid electrolyte made of a material). In this regard, according to the present invention, the above-described increase in the resistance value of the battery can be significantly reduced by controlling the degree of orientation of the oriented polycrystalline body constituting the positive electrode plate 12 to 15 to 85%. Although the mechanism that brings about this advantageous effect is not necessarily clear, the expansion and contraction of the positive electrode plate 12 due to the desorption / insertion of lithium ions accompanying charging / discharging is suppressed to be low within the above-mentioned orientation degree range. This is because the stress in the positive electrode plate 12 can be kept small, and as a result, it is possible to maintain a good interface state (for example, no peeling) with little distortion between the positive electrode plate 12 and the solid electrolyte layer 14. Inferred. That is, it is considered that the increase in resistance at the interface between the positive electrode plate 12 and the solid electrolyte layer 14 is reduced. In addition, according to the knowledge of the present inventors, this low expansion / contraction rate is also correlated with the composition of the positive electrode plate 12, and therefore the orientation degree range of 15 to 85% is specific to the composition of the positive electrode plate described above. (For example, when the positive electrode plate is made of LiCoO 2 , the low expansion / contraction rate is not realized). However, the invention should not be construed as being limited to the above theory since other factors that bring about the above-described effects of the present invention are also possible.
　正極板１２は、層状岩塩構造を有する複数のリチウム遷移金属酸化物粒子からなる配向多結晶体からなる。層状岩塩構造は、リチウムイオンの吸蔵により酸化還元電位が低下し、リチウムイオンの脱離により酸化還元電位が上昇する性質があり、好ましく、中でもＮｉを多く含む組成は特に好ましい。ここで、層状岩塩構造とは、リチウム以外の遷移金属系層とリチウム層とが酸素原子の層を挟んで交互に積層された結晶構造、すなわち、リチウム以外の遷移金属等のイオン層とリチウムイオン層とが酸化物イオンを挟んで交互に積層された結晶構造（典型的にはα－ＮａＦｅＯ２型構造：立方晶岩塩型構造の［１１１］軸方向に遷移金属とリチウムとが規則配列した構造）をいう。本発明に用いる層状岩塩構造を有するリチウム遷移金属酸化物粒子は、Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０＜ｘ＜０．８、０＜ｙ＜１、０≦ｚ≦０．７、ｘ＋ｙ＋ｚ＝１（好ましくは０．９５≦ｐ≦１．１、０．１≦ｘ＜０．７、０．１≦ｙ＜０．９、０≦ｚ≦０．６、ｘ＋ｙ＋ｚ＝１）又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０．６＜ｘ＜０．９、０．１＜ｙ≦０．３、０≦ｚ≦０．２、ｘ＋ｙ＋ｚ＝１（好ましくは０．９５≦ｐ≦１．１、０．７＜ｘ＜０．９、０．１＜ｙ≦０．２５、０≦ｚ≦０．１、ｘ＋ｙ＋ｚ＝１））で表される基本組成を有する。これらの組成は、層状岩塩構造を有するリチウム遷移金属酸化物のうちニッケル及びコバルトを含む組成である。ニッケル及びコバルトを含むことで充放電時の正極板１２の膨張収縮率が有意に低減されうる。そのような組成を典型例としては、ニッケル・コバルト酸リチウム、コバルト・ニッケル・マンガン酸リチウム、ニッケル・コバルト・アルミニウム酸リチウム等が挙げられる。リチウム遷移金属酸化物粒子ないしその配向多結晶体には、Ｍｇ，Ａｌ，Ｓｉ，Ｃａ，Ｔｉ，Ｖ，Ｃｒ，Ｆｅ，Ｃｕ，Ｚｎ，Ｇａ，Ｇｅ，Ｓｒ，Ｙ，Ｚｒ，Ｎｂ，Ｍｏ，Ａｇ，Ｓｎ，Ｓｂ，Ｔｅ，Ｂａ，Ｂｉ等の元素が１種以上更にドーピング又はそれに準ずる形態（例えば結晶粒子の表層への部分的な固溶、又は偏析）で微量添加されていてもよい。 The positive electrode plate 12 is made of an oriented polycrystal composed of a plurality of lithium transition metal oxide particles having a layered rock salt structure. The layered rock salt structure has a property that the oxidation-reduction potential decreases due to occlusion of lithium ions and the oxidation-reduction potential increases due to elimination of lithium ions, and a composition containing a large amount of Ni is particularly preferable. Here, the layered rock salt structure is a crystal structure in which transition metal layers other than lithium and lithium layers are alternately stacked with an oxygen atom layer interposed therebetween, that is, an ion layer and lithium ions of transition metals other than lithium. Crystal structure in which layers are alternately stacked with oxide ions (typically α-NaFeO 2 type structure: a structure in which transition metal and lithium are regularly arranged in the [111] axis direction of cubic rock salt type structure ). Lithium transition metal oxide particles having a layered rock salt structure used in the present invention, Li p (Ni x, Co y, Mn z) O 2 ( wherein, 0.9 ≦ p ≦ 1.3,0 <x <0 .8, 0 <y <1, 0 ≦ z ≦ 0.7, x + y + z = 1 (preferably 0.95 ≦ p ≦ 1.1, 0.1 ≦ x <0.7, 0.1 ≦ y <0 .9, 0 ≦ z ≦ 0.6, x + y + z = 1) or Li p (Ni x , Co y , Al z ) O 2 (where 0.9 ≦ p ≦ 1.3, 0.6 <x < 0.9, 0.1 <y ≦ 0.3, 0 ≦ z ≦ 0.2, x + y + z = 1 (preferably 0.95 ≦ p ≦ 1.1, 0.7 <x <0.9,. 1 <y ≦ 0.25, 0 ≦ z ≦ 0.1, x + y + z = 1)) These compositions are nickel and cobalt among lithium transition metal oxides having a layered rock salt structure. By including nickel and cobalt, the expansion / contraction rate of the positive electrode plate 12 during charging / discharging can be significantly reduced.Typical examples of such a composition include nickel-lithium cobaltate, cobalt-nickel- Examples thereof include lithium manganate, nickel / cobalt / lithium aluminum oxide, etc. The lithium transition metal oxide particles or their oriented polycrystals include Mg, Al, Si, Ca, Ti, V, Cr, Fe, Cu, Zn. , Ga, Ge, Sr, Y, Zr, Nb, Mo, Ag, Sn, Sb, Te, Ba, Bi, etc. are further doped or in a form equivalent thereto (for example, a partial surface layer of crystal grains) A small amount may be added by solid solution or segregation).
　前述のとおり、正極板１２は、複数のリチウム遷移金属酸化物粒子からなる配向多結晶体からなる。この配向多結晶体は、一定の方向に配向された複数のリチウム遷移金属酸化物粒子からなるのが好ましい。この一定の方向は、リチウムイオンの伝導方向であるのが好ましく、典型的には、正極板１２を構成する各粒子の特定の結晶面が正極板１２から負極層１６に向かう方向に配向されてなる。リチウム遷移金属酸化物粒子は、厚さが２～１００μｍ程度の板状に形成された粒子が好ましい。特に、上述の特定の結晶面が（００３）面であり、該（００３）面が正極板１２から負極層１６に向かう方向に配向されていることが好ましい。これにより、リチウムイオンの正極板１２に対する脱挿入の際の抵抗にならず、高入力時（充電時）に、多くのリチウムイオンを放出することができ、高出力時（放電時）に、多くのリチウムイオンを受け入れることができる。（００３）面以外の例えば（１０１）面や（１０４）面は、正極板１２の板面に沿うように配向させてもよい。上述の粒子や配向多結晶体の詳細については、特許文献３～５を参照することができ、これらの文献の開示内容は参照により本明細書に組み込まれる。 As described above, the positive electrode plate 12 is made of an oriented polycrystal formed of a plurality of lithium transition metal oxide particles. This oriented polycrystal is preferably composed of a plurality of lithium transition metal oxide particles oriented in a certain direction. The certain direction is preferably a lithium ion conduction direction. Typically, a specific crystal plane of each particle constituting the positive electrode plate 12 is oriented in a direction from the positive electrode plate 12 toward the negative electrode layer 16. Become. The lithium transition metal oxide particles are preferably particles formed in a plate shape having a thickness of about 2 to 100 μm. In particular, it is preferable that the specific crystal plane described above is a (003) plane, and the (003) plane is oriented in a direction from the positive electrode plate 12 toward the negative electrode layer 16. Thereby, it does not become a resistance at the time of insertion / removal of the lithium ion with respect to the positive electrode plate 12, but can release many lithium ions at the time of high input (charge) and much at the time of high output (discharge). Can accept lithium ions. For example, the (101) plane or the (104) plane other than the (003) plane may be oriented along the plate surface of the positive electrode plate 12. For details of the above-described particles and oriented polycrystals, Patent Documents 3 to 5 can be referred to, and the disclosure contents of these documents are incorporated herein by reference.
　すなわち、正極板１２は配向多結晶体からなり、この配向多結晶体は１５～８５％、好ましくは２０～８０％、より好ましくは３０～７５％、さらに好ましくは４０～７５％、特に好ましくは４５～７５％、最も好ましくは４０～７０％の配向度を有する。もっとも、これらの様々な配向度範囲の上限値及び下限値は任意に組み合わせてよい。換言すれば、配向度は、下限値に関して、１５％以上、好ましくは２０％以上、より好ましくは３０％以上、さらに好ましくは４０％以上、特に好ましくは４５％以上であり、かつ、上限値に関して、８５％以下、好ましくは８０％以下であり、より好ましくは７５％以下であり、最も好ましくは７０％以下である。なお、この配向度は、正極板１２の板面を試料面とし、ＸＲＤ装置（例えば、株式会社リガク製、ＴＴＲ－ＩＩＩ）を用いて、Ｘ線回折を２θで１０°から７０°の範囲を２°／ｍｉｎ、ステップ幅０．０２°の条件で行い、得られたＸＲＤプロファイルをロットゲーリング法に従い下記式に基づいて配向度を算出すればよい。
Figure JPOXMLDOC01-appb-M000001
 （上記式中、Ｉは正極板試料の回折強度であり、Ｉ０は無配向の参照試料の回折強度である。（ＨＫＬ）は配向度を評価したい回折線であり、（００ｌ）（ｌは例えば３、６及び９である）以外の回折線に相当にする。（ｈｋｌ）は全ての回折線に相当する。） That is, the positive electrode plate 12 is made of an oriented polycrystal, and this oriented polycrystal is 15 to 85%, preferably 20 to 80%, more preferably 30 to 75%, still more preferably 40 to 75%, particularly preferably. It has an orientation degree of 45-75%, most preferably 40-70%. However, the upper limit value and the lower limit value of these various orientation degree ranges may be arbitrarily combined. In other words, the degree of orientation is at least 15%, preferably at least 20%, more preferably at least 30%, even more preferably at least 40%, particularly preferably at least 45% with respect to the lower limit, and with respect to the upper limit. 85% or less, preferably 80% or less, more preferably 75% or less, and most preferably 70% or less. Note that this degree of orientation is such that the plate surface of the positive electrode plate 12 is the sample surface, and X-ray diffraction is in the range of 10 ° to 70 ° at 2θ using an XRD apparatus (eg, TTR-III, manufactured by Rigaku Corporation). The degree of orientation may be calculated based on the following formula using the obtained XRD profile according to the Lotgering method, under the conditions of 2 ° / min and a step width of 0.02 °.
Figure JPOXMLDOC01-appb-M000001
 (In the above formula, I is the diffraction intensity of the positive electrode plate sample, I 0 is the diffraction intensity of the non-oriented reference sample. (HKL) is the diffraction line for which the degree of orientation is to be evaluated, and (00l) (l is (For example, 3, 6 and 9.) (hkl) corresponds to all diffraction lines.)
　なお、この無配向の参照試料は、無配向であること以外は正極板試料と同様の構成の試料であり、例えば正極板試料を乳鉢で粉砕して無配向状態にすることで得ることができる。また、上記式において、（ＨＫＬ）に関して、（００ｌ）の回折線が除かれているのは、この回折線に相当する面（例えば（００３）面）はその面内方向（当該面と平行方向）にしかリチウムイオンが移動できないため、当該面が正極板１２の板面に沿って配向されているとリチウムイオンの移動が妨げられるからである。したがって、複数のリチウム遷移金属酸化物粒子は、層状岩塩構造の（００３）面が正極板１２の板面と交差するような方向に配向されてなるのが好ましい。すなわち、この正極板１２の板面と交差するような方向がリチウムイオンの伝導方向であり、この構成によれば、正極板１２を構成する各粒子の（００３）面が正極板１２から負極層１６に向かう方向に配向されることになる。 The non-oriented reference sample is a sample having the same configuration as the positive electrode plate sample except that it is non-oriented. For example, the non-oriented reference sample can be obtained by pulverizing the positive electrode plate sample with a mortar to make it non-oriented. . In the above formula, with respect to (HKL), the (001) diffraction line is removed because the plane corresponding to this diffraction line (for example, the (003) plane) is the in-plane direction (the direction parallel to the plane). This is because the movement of lithium ions is hindered when the surface is oriented along the plate surface of the positive electrode plate 12. Therefore, the plurality of lithium transition metal oxide particles are preferably oriented in such a direction that the (003) plane of the layered rock salt structure intersects the plate surface of the positive electrode plate 12. That is, the direction that intersects the plate surface of the positive electrode plate 12 is the lithium ion conduction direction. According to this configuration, the (003) surface of each particle constituting the positive electrode plate 12 extends from the positive electrode plate 12 to the negative electrode layer. It will be oriented in the direction towards 16.
　前述したとおり、正極板１２を構成する配向多結晶体は、無配向の多結晶体よりも、厚くするのに適している。配向多結晶体の厚さは、単位面積当りの活物質容量を高くする観点から、１０μｍ以上が好ましく、より好ましくは１３μｍ以上であり、さらに好ましくは１６μｍ以上、特に好ましくは２０μｍ以上、最も好ましくは２５μｍ以上である。厚さの上限値は特に限定されないが、充放電の繰り返しに伴う電池特性の劣化（特に抵抗値の上昇）を低減する観点から、好ましくは１００μｍ未満、より好ましくは９０μｍ以下、さらに好ましくは８０μｍ以下、特に好ましくは７０μｍ以下、最も好ましくは６０μｍである。 As described above, the oriented polycrystalline body constituting the positive electrode plate 12 is suitable for making it thicker than the non-oriented polycrystalline body. The thickness of the oriented polycrystal is preferably 10 μm or more, more preferably 13 μm or more, further preferably 16 μm or more, particularly preferably 20 μm or more, and most preferably from the viewpoint of increasing the active material capacity per unit area. It is 25 μm or more. The upper limit value of the thickness is not particularly limited, but is preferably less than 100 μm, more preferably 90 μm or less, and even more preferably 80 μm or less from the viewpoint of reducing deterioration of battery characteristics (particularly increase in resistance value) due to repeated charge / discharge. Particularly preferably, it is 70 μm or less, and most preferably 60 μm.
　正極板１２はシート状に形成されるのが好ましい。このシート状に形成された正極活物質（以下、正極活物質シートという）の好ましい製造方法については後述する。なお、１枚の正極活物質シートで正極板１２を構成してもよいし、正極活物質シートを分割して得られた複数個の小片を層状に配列させて正極板１２を構成してもよい。 The positive electrode plate 12 is preferably formed in a sheet shape. A preferred method for producing a positive electrode active material (hereinafter referred to as a positive electrode active material sheet) formed in the form of a sheet will be described later. The positive electrode plate 12 may be constituted by one positive electrode active material sheet, or the positive electrode plate 12 may be constituted by arranging a plurality of small pieces obtained by dividing the positive electrode active material sheet in layers. Good.
　正極板１２の固体電解質層１４側の表面は、０．０５μｍより大きく３．０μｍ未満の算術平均粗さＲａを有するのが好ましく、より好ましくは０．１０～２．５μｍ、さらに好ましくは０．１３～２．０μｍ、特に好ましくは０．１６～１．５μｍ、最も好ましくは０．２０～１．０μｍの算術平均粗さＲａを有する。算術平均粗さＲａはＪＩＳ　Ｂ　０６０１－２００１に準拠して決定される値であり、市販の表面粗さ測定機で測定することができる。このように正極板１２の固体電解質層１４側の表面粗さを上記範囲内に制御することで、適度な表面粗さにより正極板１２と固体電解質層１４との接触点（これはリチウムイオン伝導経路になる）を十分に確保しながら、適度に高い平滑性により正極板１２と固体電解質層１４との間で、充放電の繰り返しによっても抵抗値が上昇しにくい密着性に優れた望ましい界面を形成することができる。上記範囲内の算術平均粗さＲａは、正極板１２の製造条件を適宜調整すること（例えば原料粒径の微細化、焼成スケジュール、成形体の高密度化等）によって実現してもよいし、正極板の表面をラッピングフィルム、リューター等で研磨することにより実現してもよい。 The surface of the positive electrode plate 12 on the solid electrolyte layer 14 side preferably has an arithmetic average roughness Ra of more than 0.05 μm and less than 3.0 μm, more preferably 0.10 to 2.5 μm, and still more preferably 0.8. It has an arithmetic average roughness Ra of 13 to 2.0 μm, particularly preferably 0.16 to 1.5 μm, most preferably 0.20 to 1.0 μm. The arithmetic average roughness Ra is a value determined according to JIS B 0601-2001, and can be measured with a commercially available surface roughness measuring machine. In this way, by controlling the surface roughness of the positive electrode plate 12 on the solid electrolyte layer 14 side within the above range, the contact point between the positive electrode plate 12 and the solid electrolyte layer 14 (this is lithium ion conduction) with an appropriate surface roughness. A desirable interface excellent in adhesion, in which the resistance value is not easily increased by repeated charge / discharge between the positive electrode plate 12 and the solid electrolyte layer 14 due to moderately high smoothness. Can be formed. The arithmetic average roughness Ra within the above range may be realized by appropriately adjusting the manufacturing conditions of the positive electrode plate 12 (for example, refining the raw material particle size, firing schedule, densification of the molded body, etc.) You may implement | achieve by grind | polishing the surface of a positive electrode plate with a wrapping film, a leuter, etc.
　正極板１２を構成する配向多結晶体は７５～９９．９７％の相対密度を有するのが好ましく、より好ましくは８０～９９．９５％、さらに好ましくは９０～９９．９０％、特に好ましくは９５～９９．８８％、最も好ましくは９７～９９．８５％の相対密度を有する。容量及びエネルギー密度の観点から相対密度は基本的には高い方が望ましいが、上記範囲内であると充放電の繰り返しによっても抵抗値が上昇しにくい。これは上記相対密度であるとリチウムの脱挿入に伴い正極板１２が適度に膨張収縮でき、それにより応力を緩和できるためではないかと考えられる。 The oriented polycrystalline body constituting the positive electrode plate 12 preferably has a relative density of 75 to 99.97%, more preferably 80 to 99.95%, still more preferably 90 to 99.90%, and particularly preferably 95. It has a relative density of ˜99.88%, most preferably 97-99.85%. From the viewpoint of capacity and energy density, it is basically desirable that the relative density be high, but if it is within the above range, the resistance value is unlikely to increase even after repeated charge and discharge. It is thought that this is because the positive electrode plate 12 can be appropriately expanded and contracted as lithium is deinserted and the stress can be relieved by the relative density.
　固体電解質層１４はＬｉ－Ｌａ－Ｚｒ－Ｏ系セラミックス材料及び／又はリン酸リチウムオキシナイトライド（ＬｉＰＯＮ）系セラミックス材料で構成される。Ｌｉ－Ｌａ－Ｚｒ－Ｏ系材料は、Ｌｉ、Ｌａ、Ｚｒ及びＯを含んで構成されるガーネット型又はガーネット型類似の結晶構造を有する酸化物焼結体であり、具体的には、Ｌｉ７Ｌａ３Ｚｒ２Ｏ１２などのガーネット系セラミックス材料である。このような材料としては、特許文献６～８に記載されるものも用いることができ、これらの文献の開示内容は参照により本明細書に組み込まれる。ガーネット系セラミックス材料は、負極リチウムと直接接触しても反応が起きないリチウムイオン伝導材料であるが、とりわけ、Ｌｉ、Ｌａ、Ｚｒ及びＯを含んで構成されるガーネット型又はガーネット型類似の結晶構造を有する酸化物焼結体が、焼結性に優れて緻密化しやすく、かつ、イオン伝導率も高い。この種の組成のガーネット型又はガーネット型類似の結晶構造はＬＬＺ結晶構造と呼ばれ、ＣＳＤ（Cambridge Structural Database）のＸ線回折ファイルＮｏ．４２２２５９（Ｌｉ７Ｌａ３Ｚｒ２Ｏ１２）に類似のＸＲＤパターンを有する。なお、Ｎｏ．４２２２５９と比較すると構成元素が異なり、またセラミックス中のＬｉ濃度などが異なる可能性があるため、回折角度や回折強度比が異なる場合もある。Ｌａに対するＬｉのモル数の比Ｌｉ／Ｌａは２．０以上２．５以下であることが好ましく、Ｌａに対するＺｒのモル比Ｚｒ／Ｌａは０．５以上０．６７以下であるのが好ましい。このガーネット型又はガーネット型類似の結晶構造はＮｂ及び／又はＴａをさらに含んで構成されるものであってもよい。すなわち、ＬＬＺのＺｒの一部がＮｂ及びＴａのいずれか一方又は双方で置換されることにより、置換前に比べて伝導率を向上させることができる。ＺｒのＮｂ及び／又はＴａによる置換量（モル比）は、（Ｎｂ＋Ｔａ）／Ｌａのモル比が０．０３以上０．２０以下となる量にすることが好ましい。また、このガーネット系酸化物焼結体はＡｌをさらに含んでいるのが好ましく、これらの元素は結晶格子に存在してもよいし、結晶格子以外に存在していてもよい。Ａｌの添加量は焼結体の０．０１～１質量％とするのが好ましく、Ｌａに対するＡｌのモル比Ａｌ／Ｌａは、０．００８～０．１２であるのが好ましい。このようなＬＬＺ系セラミックスの製造は、特許文献６～８に記載されるような公知の手法に従って又はそれを適宜修正することにより行うことができ、これらの文献の開示内容は本明細書に参照により組み込まれる。また、リン酸リチウムオキシナイトライド（ＬｉＰＯＮ）系セラミックス材料も好ましい。ＬｉＰＯＮは、Ｌｉ２．９ＰＯ３．３Ｎ０．４６の組成によって代表されるような化合物群であり、例えばＬｉａＰＯｂＮｃ（式中、ａは２～４、ｂは３～５、ｃは０．１～０．９である）で表される化合物群である。 The solid electrolyte layer 14 is composed of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material. The Li—La—Zr—O-based material is an oxide sintered body having a garnet-type or garnet-type similar crystal structure including Li, La, Zr, and O. Specifically, Li 7 A garnet-based ceramic material such as La 3 Zr 2 O 12 . As such materials, those described in Patent Documents 6 to 8 can also be used, and the disclosure content of these documents is incorporated herein by reference. The garnet-based ceramic material is a lithium ion conductive material that does not react even when directly contacted with the negative electrode lithium, and in particular, a garnet-type or garnet-type similar crystal structure including Li, La, Zr, and O Oxide sintered bodies having excellent sinterability and easy densification and high ionic conductivity. A garnet-type or garnet-like crystal structure of this type of composition is called an LLZ crystal structure, and is referred to as an X-ray diffraction file No. of CSD (Cambridge Structural Database). It has an XRD pattern similar to 422259 (Li 7 La 3 Zr 2 O 12 ). In addition, No. Compared to 422259, the constituent elements are different and the Li concentration in the ceramics may be different, so the diffraction angle and the diffraction intensity ratio may be different. The molar ratio Li / La of Li to La is preferably 2.0 or more and 2.5 or less, and the molar ratio Zr / La to La is preferably 0.5 or more and 0.67 or less. This garnet-type or garnet-like crystal structure may further comprise Nb and / or Ta. That is, by replacing a part of Zr of LLZ with one or both of Nb and Ta, the conductivity can be improved as compared with that before the substitution. The substitution amount (molar ratio) of Zr with Nb and / or Ta is preferably set such that the molar ratio of (Nb + Ta) / La is 0.03 or more and 0.20 or less. The garnet-based oxide sintered body preferably further contains Al, and these elements may exist in the crystal lattice or may exist in other than the crystal lattice. The amount of Al added is preferably 0.01 to 1% by mass of the sintered body, and the molar ratio Al / La to La is preferably 0.008 to 0.12. Such LLZ-based ceramics can be produced according to a known technique as described in Patent Documents 6 to 8, or by appropriately modifying it, and the disclosure of these documents is referred to in this specification. Is incorporated. A lithium phosphate oxynitride (LiPON) ceramic material is also preferable. LiPON is a group of compounds represented by the composition of Li 2.9 PO 3.3 N 0.46 . For example, Li a PO b N c (wherein a is 2 to 4 and b is 3 to 5 , C is 0.1 to 0.9).
　固体電解質層１４の寸法は特に限定されないが、厚さは充放電レート特性と機械的強度の観点から、０．０００５ｍｍ～０．５ｍｍが好ましく、より好ましくは０．００１ｍｍ～０．１ｍｍ、さらに好ましくは０．００５～０．０５ｍｍである。 The dimensions of the solid electrolyte layer 14 are not particularly limited, but the thickness is preferably 0.0005 mm to 0.5 mm, more preferably 0.001 mm to 0.1 mm, and still more preferably, from the viewpoints of charge / discharge rate characteristics and mechanical strength. Is 0.005 to 0.05 mm.
　固体電解質層１４の形成方法としては、各種パーティクルジェットコーティング法、固相法、溶液法、気相法、直接接合（ダイレクトボンディング）法を用いることができる。パーティクルジェットコーティング法の例としては、エアロゾルデポジション（ＡＤ）法、ガスデポジション（ＧＤ）法、パウダージェットデポジション（ＰＪＤ）法、コールドスプレー（ＣＳ）法、溶射法等がある。中でも、エアロゾルデポジション（ＡＤ）法は、常温成膜が可能であることから、プロセス中の組成ズレや、正極板との反応による高抵抗層の形成がなく特に好ましい。固相法の例としては、テープ積層法、印刷法等がある。中でも、テープ積層法は固体電解質層１４を薄く形成することが可能であり、また、厚さの制御が容易であることから好ましい。溶液法の例としては、ソルボサーマル法、水熱合成法、ゾルゲル法、沈殿法、マイクロエマルション法、溶媒蒸発法等がある。これらの方法の中でも、水熱合成法は、低温で結晶性の高い結晶粒を得やすい点で特に好ましい。また、これらの方法を用いて合成した微結晶を、正極上に堆積させてもよいし、正極上に直接析出させてもよい。気相法の例としては、レーザー堆積（ＰＬＤ）法、スパッタ法、蒸発凝縮（ＰＶＤ）法、気相反応法（ＣＶＤ）法、真空蒸着法、分子線エピタキシ（ＭＢＥ）法等がある。この中でも、レーザー堆積（ＰＬＤ）法は組成ズレが少なく、比較的結晶性の高い膜を得られやすく特に好ましい。直接接合（ダイレクトボンディング）法は、予め形成した固体電解質層１４と正極板１２の各々の表面を化学的に活性な状態にして、低温で接合する方法である。界面の活性化については、プラズマ等を用いてもよいし、水酸基等の官能基の化学修飾を用いてもよい。 As the method for forming the solid electrolyte layer 14, various particle jet coating methods, solid phase methods, solution methods, gas phase methods, and direct bonding methods can be used. Examples of the particle jet coating method include an aerosol deposition (AD) method, a gas deposition (GD) method, a powder jet deposition (PJD) method, a cold spray (CS) method, and a thermal spraying method. Among these, the aerosol deposition (AD) method is particularly preferable because it can form a film at room temperature, and does not cause a composition shift during the process or formation of a high resistance layer due to a reaction with the positive electrode plate. Examples of the solid phase method include a tape lamination method and a printing method. Among these, the tape lamination method is preferable because the solid electrolyte layer 14 can be formed thin and the thickness can be easily controlled. Examples of the solution method include a solvothermal method, a hydrothermal synthesis method, a sol-gel method, a precipitation method, a microemulsion method, and a solvent evaporation method. Among these methods, the hydrothermal synthesis method is particularly preferable in that it is easy to obtain crystal grains having high crystallinity at a low temperature. In addition, microcrystals synthesized using these methods may be deposited on the positive electrode or may be directly deposited on the positive electrode. Examples of the gas phase method include laser deposition (PLD) method, sputtering method, evaporation condensation (PVD) method, gas phase reaction method (CVD) method, vacuum deposition method, molecular beam epitaxy (MBE) method and the like. Among these, the laser deposition (PLD) method is particularly preferable because there is little composition deviation and a film with relatively high crystallinity can be easily obtained. The direct bonding (direct bonding) method is a method in which the surfaces of the solid electrolyte layer 14 and the positive electrode plate 12 formed in advance are chemically activated and bonded at a low temperature. For activation of the interface, plasma or the like may be used, or chemical modification of a functional group such as a hydroxyl group may be used.
　正極板１２と固体電解質層１４の間の界面には界面抵抗を下げるための処理が施されていてもよい。例えば、そのような処理は、ニオブ酸化物、チタン酸化物、タングステン酸化物、タンタル酸化物、リチウム・ニッケル複合酸化物、リチウム・チタン複合酸化物、リチウム・ニオブ化合物、リチウム・タンタル化合物、リチウム・タングステン化合物、リチウム・チタン化合物、及びこれらの任意の組み合わせ若しくは複合酸化物で正極板１２の表面及び／又は固体電解質層１４の表面を被覆することにより行うことができる。このような処理によって正極板１２と固体電解質層１４の間の界面には被膜が存在しうることになるが、その被膜の厚さは例えば２０ｎｍ以下といったような極めて薄いものである。 The interface between the positive electrode plate 12 and the solid electrolyte layer 14 may be subjected to a treatment for reducing the interface resistance. For example, such treatment includes niobium oxide, titanium oxide, tungsten oxide, tantalum oxide, lithium-nickel composite oxide, lithium-titanium composite oxide, lithium-niobium compound, lithium-tantalum compound, lithium- This can be done by coating the surface of the positive electrode plate 12 and / or the surface of the solid electrolyte layer 14 with a tungsten compound, a lithium / titanium compound, and any combination or composite oxide thereof. By such treatment, a film can exist at the interface between the positive electrode plate 12 and the solid electrolyte layer 14, and the thickness of the film is extremely thin, for example, 20 nm or less.
　負極層１６は負極活物質を含んでなり、この負極活物質は全固体リチウム電池に使用可能な公知各種の負極活物質であってよい。負極活物質の好ましい例としては、リチウム金属、リチウム合金、炭素質材料、チタン酸リチウム（ＬＴＯ）等が挙げられる。好ましくは、負極層１６は、負極集電体１７（銅箔等）の上に、リチウム金属あるいはリチウムと合金化する金属の薄膜を真空蒸着法、スパッタリング法、ＣＶＤ法等で形成して、リチウム金属あるいはリチウムと合金化する金属の層を形成することにより作製することができる。 The negative electrode layer 16 includes a negative electrode active material, and this negative electrode active material may be any of various known negative electrode active materials that can be used in an all-solid lithium battery. Preferable examples of the negative electrode active material include lithium metal, lithium alloy, carbonaceous material, lithium titanate (LTO) and the like. Preferably, the negative electrode layer 16 is formed by forming a thin film of lithium metal or a metal alloying with lithium on the negative electrode current collector 17 (copper foil or the like) by vacuum deposition, sputtering, CVD, or the like. It can be produced by forming a metal or metal layer that is alloyed with lithium.
　負極層１６と固体電解質層１４の間に中間層を介在させるのが好ましい。中間層の構成材料としては、リチウムと合金化する金属、酸化物系材料等を用いることができる。この場合、充放電サイクル特性を向上させることができる。リチウムと合金化する金属の例としては、Ａｌ（アルミニウム）、Ｓｉ（シリコン）、Ｚｎ（亜鉛）、Ｇａ（ガリウム）、Ｇｅ（ゲルマニウム）、Ａｇ（銀）、Ａｕ（金）、Ｃｄ（カドミウム）、Ｉｎ（インジウム）、Ｓｎ（スズ）、Ｓｂ（アンチモン）、Ｐｂ（鉛）、Ｂｉ（ビスマス）、及びそれらの任意の組み合わせが挙げられる。リチウムと合金化する金属は、Ｍｇ２ＳｉやＭｇ２Ｓｎ等の２種類以上の元素により構成された合金であってもよい。酸化物系材料の例としては、Ｌｉ４Ｔｉ５Ｏ１２、ＴｉＯ２、ＳｉＯ等が挙げられる。中間層の形成は、エアロゾルデポジション（ＡＤ）法、パルスレーザー堆積（ＰＬＤ）法、スパッタリング法等の公知の方法により行えばよい。 It is preferable to interpose an intermediate layer between the negative electrode layer 16 and the solid electrolyte layer 14. As a constituent material of the intermediate layer, a metal alloyed with lithium, an oxide-based material, or the like can be used. In this case, charge / discharge cycle characteristics can be improved. Examples of metals alloyed with lithium include Al (aluminum), Si (silicon), Zn (zinc), Ga (gallium), Ge (germanium), Ag (silver), Au (gold), and Cd (cadmium). , In (indium), Sn (tin), Sb (antimony), Pb (lead), Bi (bismuth), and any combination thereof. The metal alloyed with lithium may be an alloy composed of two or more elements such as Mg 2 Si and Mg 2 Sn. Examples of the oxide material include Li 4 Ti 5 O 12 , TiO 2 , and SiO. The intermediate layer may be formed by a known method such as an aerosol deposition (AD) method, a pulse laser deposition (PLD) method, or a sputtering method.
　正極板１２及び／又は負極層１６には正極集電体１３及び／又は負極集電体１７が設けられるのが好ましい。典型的には、図１に示されるように、正極集電体１３は正極板１２の固体電解質層１４と反対側の面に設けられる一方、負極集電体１７は負極層１６の固体電解質層１４と反対側の面に設けられる。正極集電体１３及び負極集電体１７を構成する材料の例としては、白金（Ｐｔ）、白金（Ｐｔ）／パラジウム（Ｐｄ）、金（Ａｕ）、銀（Ａｇ）、アルミニウム（Ａｌ）、銅（Ｃｕ）、ＩＴＯ（インジウム－錫酸化膜）、Ｎｉ（ニッケル）等が挙げられる。 The positive electrode plate 12 and / or the negative electrode layer 16 are preferably provided with a positive electrode current collector 13 and / or a negative electrode current collector 17. Typically, as shown in FIG. 1, the positive electrode current collector 13 is provided on the surface of the positive electrode plate 12 opposite to the solid electrolyte layer 14, while the negative electrode current collector 17 is formed of the solid electrolyte layer of the negative electrode layer 16. 14 is provided on the opposite side of the surface. Examples of materials constituting the positive electrode current collector 13 and the negative electrode current collector 17 include platinum (Pt), platinum (Pt) / palladium (Pd), gold (Au), silver (Ag), aluminum (Al), Examples thereof include copper (Cu), ITO (indium-tin oxide film), and Ni (nickel).
　容器１８は、単位電池又はそれを複数個直列若しくは並列に積層させたスタックを収容可能な容器であれば特に限定されない。特に、全固体リチウム電池１０は電解液の漏れの懸念が無いため、容器１８は比較的簡素な容器形態を採用可能である。例えば、電子回路に実装するためのチップ形態、薄く幅広の空間用途のためのラミネートセル形態（例えばアルミニウム（Ａｌ）／ポリプロピレン（ＰＰ）の複層品）、樹脂モールド形態、金属板で電池構成部材を挟む形態等が採用可能である。 The container 18 is not particularly limited as long as it can accommodate a unit battery or a stack in which a plurality of unit batteries are stacked in series or in parallel. In particular, since the all-solid lithium battery 10 has no fear of electrolyte leakage, the container 18 can adopt a relatively simple container form. For example, a chip configuration for mounting on an electronic circuit, a laminate cell configuration for thin and wide space applications (for example, a multilayer product of aluminum (Al) / polypropylene (PP)), a resin mold configuration, a battery component in a metal plate The form etc. which pinch | interpose can be employ | adopted.
　正極活物質シートの製造方法
　正極活物質シートの好ましい製造方法について以下に説明する。 Method for Producing Positive Electrode Active Material Sheet A preferred method for producing the positive electrode active material sheet is described below.
（１）原料粒子の準備
　原料粒子としては、合成後の組成が層状岩塩構造を有する正極活物質ＬｉＭＯ２となるように、Ｌｉ、Ｃｏ、Ｎｉ、Ｍｎ、Ａｌなどの化合物の粒子を適宜混合したものが用いられる。あるいは、原料粒子として、ＬｉＭＯ２の組成からなるもの（合成済みのもの）を用いることができる。 (1) Preparation of raw material particles As raw material particles, particles of a compound such as Li, Co, Ni, Mn, and Al were appropriately mixed so that the composition after synthesis was a positive electrode active material LiMO 2 having a layered rock salt structure. Things are used. Alternatively, raw material particles having a composition of LiMO 2 (synthesized particles) can be used.
　あるいは、必要に応じて、リチウム化合物を含まない原料粒子を用いてもよい。この場合、成形体の焼成工程の後、焼成された成形体とリチウム化合物とをさらに反応させることでＬｉＭＯ２が得られる。リチウムを含まない原料粒子としては、Ｃｏ、Ｎｉ、Ｍｎ、Ａｌ等の各化合物の混合粒子（（Ｃｏ，Ｎｉ，Ｍｎ）Ｏｘ、（Ｃｏ，Ｎｉ，Ａｌ）Ｏｘ、（Ｃｏ，Ｎｉ，Ｍｎ）ＯＨｘ、（Ｃｏ，Ｎｉ，Ａｌ）ＯＨｘ等の組成を有する混合粒子）等を用いることができる。好ましくは、少なくとも１種の金属化合物が、Ｃｏ、Ｎｉ、Ｍｎ及びＡｌからなる群から選択される少なくとも１種の金属の、酸化物、水酸化物及び／又は炭酸塩である。また、これらの粒子は二種以上の金属化合物粒子の混合粉の形態でもよいし、共沈法により合成した複合化合物からなる粒子であってもよい。 Or you may use the raw material particle | grains which do not contain a lithium compound as needed. In this case, LiMO 2 is obtained by further reacting the fired molded body with the lithium compound after the firing process of the molded body. As raw material particles not containing lithium, mixed particles ((Co, Ni, Mn) O x , (Co, Ni, Al) O x , (Co, Ni, Mn) of compounds such as Co, Ni, Mn, and Al are used. ) OH x , (Co, Ni, Al) OH x, etc.). Preferably, the at least one metal compound is an oxide, hydroxide and / or carbonate of at least one metal selected from the group consisting of Co, Ni, Mn and Al. These particles may be in the form of a mixed powder of two or more kinds of metal compound particles, or may be particles made of a composite compound synthesized by a coprecipitation method.
　粒成長を促進する、もしくは焼成中に揮発する分を補償する目的で、リチウム化合物を０．５～３０ｍｏｌ％過剰に入れてもよい。また、粒成長を促進する目的で、酸化ビスマスなどの低融点酸化物、ホウケイ酸ガラスなどの低融点ガラスを０．００１～３０ｗｔ％添加してもよい。 For the purpose of promoting grain growth or compensating for volatilization during firing, a lithium compound may be added in an excess of 0.5 to 30 mol%. For the purpose of promoting grain growth, 0.001 to 30 wt% of a low melting point oxide such as bismuth oxide or a low melting point glass such as borosilicate glass may be added.
（２）原料粒子の成形工程
　原料粒子を、シート状の自立した成形体に成形する。すなわち、「自立した成形体」は、典型的には、それ単体でシート状の成形体の形状を保つことができるものである。なお、それ単体ではシート状の成形体の形状を保つことができないものであっても、何らかの基板上に貼り付けたり成膜したりして焼成前又は焼成後に、この基板から剥離したものも、「自立した成形体」に含まれる。 (2) Forming step of raw material particles The raw material particles are formed into a sheet-like self-supporting compact. That is, the “self-supporting molded body” typically can maintain the shape of a sheet-shaped molded body by itself. In addition, even if it alone can not keep the shape of the sheet-like molded body, it may be attached to any substrate or formed into a film and peeled off from this substrate before or after firing, Included in “self-supported compact”.
　成形体の成形方法としては、例えば、原料粒子を含むスラリーを用いたドクターブレード法が用いられ得る。また、成形体の成形には、熱したドラム上へ原料を含むスラリーを塗布し、乾燥させたものをスクレイパーで掻きとる、ドラムドライヤーが用いられ得る。また、成形体の成形には、熱した円板面へスラリーを塗布し、これを乾燥させてスクレイパーで掻きとる、ディスクドライヤーを用いることもできる。また、スプレードライヤーの条件を適宜設定することで得られる中空の造粒体も、曲率をもったシート状成形体とみることができるので、成形体として好適に用いることができる。さらに、原料粒子を含む坏土を用いた押出成形法も成形体の成形方法として利用可能である。 As a molding method of the molded body, for example, a doctor blade method using a slurry containing raw material particles can be used. In addition, a drum dryer may be used for forming a formed body, in which a slurry containing a raw material is applied onto a heated drum and the dried material is scraped off with a scraper. In addition, a disk drier can be used for forming the formed body, in which a slurry is applied to a heated disk surface, dried and scraped with a scraper. Moreover, since the hollow granulated body obtained by setting the conditions of a spray dryer suitably can also be regarded as the sheet-like molded object with a curvature, it can be used suitably as a molded object. Furthermore, an extrusion molding method using a clay containing raw material particles can also be used as a molding method of the molded body.
　ドクターブレード法を用いる場合、可撓性を有する板（例えばＰＥＴフィルムなどの有機ポリマー板など）にスラリーを塗布し、塗布したスラリーを乾燥固化して成形体とし、この成形体と板とを剥離することにより、板状多結晶粒子の焼成前の成形体を作製してもよい。成形前にスラリーや坏土を調製するときには、無機粒子を適当な分散媒に分散させ、バインダーや可塑剤などを適宜加えてもよい。また、スラリーは、粘度が５００～４０００ｃＰとなるように調製するのが好ましく、減圧化で脱泡するのが好ましい。 When using the doctor blade method, the slurry is applied to a flexible plate (for example, an organic polymer plate such as a PET film), and the applied slurry is dried and solidified to form a molded product, and the molded product and the plate are peeled off. By doing so, you may produce the molded object before baking of a plate-like polycrystalline particle. When preparing a slurry or clay before molding, inorganic particles may be dispersed in a suitable dispersion medium, and a binder, a plasticizer, or the like may be added as appropriate. The slurry is preferably prepared so as to have a viscosity of 500 to 4000 cP, and is preferably degassed under reduced pressure.
（３）成形体の焼成工程
　この焼成工程においては、成形工程で得られた成形体は、例えば、成形されたそのままの状態（シート状態）で、セッターに載せて焼成される。あるいは、焼成工程は、シート状の成形体を適宜切断、破砕したものを、鞘に入れて焼成するものであってもよい。 (3) Baking process of molded body In this baking process, the molded body obtained in the molding process is placed on a setter and fired, for example, in a molded state (a sheet state). Alternatively, the firing step may be one in which a sheet-like formed body is appropriately cut and crushed and placed in a sheath and fired.
　原料粒子が合成前の混合粒子である場合は、この焼成工程において、合成、さらには、焼結及び粒成長が生じる。本発明では、成形体がシート状であるため、厚さ方向の粒成長が限られる。このため、成形体の厚さ方向に結晶粒が１個となるまで粒成長した後は、成形体の面内方向にのみ粒成長が進む。このとき、エネルギー的に安定な特定の結晶面がシート表面（板面）に広がる。したがって、特定の結晶面がシート表面（板面）と平行になるように配向した膜状のシート（自立膜）が得られる。 If the raw material particles are mixed particles before synthesis, synthesis, further sintering and grain growth occur in this firing step. In this invention, since a molded object is a sheet form, the grain growth of the thickness direction is restricted. For this reason, after the grains have grown until the number of crystal grains becomes one in the thickness direction of the compact, grain growth proceeds only in the in-plane direction of the compact. At this time, a specific crystal plane which is stable in terms of energy spreads on the sheet surface (plate surface). Therefore, a film-like sheet (self-supporting film) oriented such that a specific crystal plane is parallel to the sheet surface (plate surface) is obtained.
　原料粒子をＬｉＭＯ２とした場合、リチウムイオンの出入りが良好に行われる結晶面である（１０１）面や（１０４）面を、シート表面（板面）に露出するように配向させることができる。一方、原料粒子を、リチウムを含まないもの（例えばスピネル構造のＭ３Ｏ４）とした場合、リチウム化合物と反応させてＬｉＭＯ２としたときに（１０４）面となる、（ｈ００）面を、シート表面（板面）に露出するように配向させることができる。 When the raw material particles are LiMO 2 , the (101) plane and (104) plane, which are crystal planes in which lithium ions can enter and exit satisfactorily, can be oriented so as to be exposed on the sheet surface (plate surface). On the other hand, when the raw material particles do not contain lithium (for example, M 3 O 4 having a spinel structure), the (h00) plane, which becomes the (104) plane when reacted with a lithium compound to form LiMO 2 , It can be oriented so as to be exposed on the sheet surface (plate surface).
　焼成温度は、７００℃～１３５０℃が好ましい。７００℃より低温では、粒成長が不十分で、配向度が低くなる。一方、１３５０℃より高温では、分解・揮発が進んでしまう。焼成時間は、１～５０時間の間とするのが好ましい。１時間より短いと、配向度が低くなる。一方、５０時間より長いと、消費エネルギーが大きくなりすぎる。焼成雰囲気は、焼成中に分解が進まないように適宜設定される。リチウムの揮発が進むような場合は、炭酸リチウムなどを同じ鞘内に配置してリチウム雰囲気とすることが好ましい。焼成中に酸素の放出や、さらには還元が進むような場合、酸素分圧の高い雰囲気で焼成することが好ましい。 The firing temperature is preferably 700 ° C to 1350 ° C. When the temperature is lower than 700 ° C., the grain growth is insufficient and the degree of orientation becomes low. On the other hand, decomposition and volatilization proceeds at a temperature higher than 1350 ° C. The firing time is preferably between 1 and 50 hours. If it is shorter than 1 hour, the degree of orientation becomes low. On the other hand, if it is longer than 50 hours, energy consumption becomes too large. The firing atmosphere is appropriately set so that decomposition does not proceed during firing. When the volatilization of lithium proceeds, it is preferable to arrange lithium carbonate or the like in the same sheath to create a lithium atmosphere. When oxygen release or further reduction proceeds during firing, firing is preferably performed in an atmosphere having a high oxygen partial pressure.
　リチウム化合物を含まない原料粒子から、焼成により配向したシート得た場合、これとリチウム化合物（硝酸リチウムや炭酸リチウムなど）を反応させることで、リチウムイオンの出入りが良好に行われる結晶面が板面に露出するように配向した、正極活物質膜が得られる。例えば、配向シート硝酸リチウムを、ＬｉとＭとのモル比Ｌｉ／Ｍが１以上となるようにふりかけて、熱処理することで、リチウム導入が行われる。ここで、熱処理温度は、６００℃～８００℃が好ましい。６００℃より低温では、反応が十分に進まない。９００℃より高温では、配向性が低下する。 When a sheet oriented by firing is obtained from raw material particles that do not contain a lithium compound, the crystal plane on which lithium ions can enter and exit satisfactorily by reacting this with a lithium compound (lithium nitrate, lithium carbonate, etc.) Thus, a positive electrode active material film oriented so as to be exposed to the surface is obtained. For example, lithium is introduced by sprinkling the orientation sheet lithium nitrate so that the molar ratio Li / M of Li and M is 1 or more and heat-treating. Here, the heat treatment temperature is preferably 600 ° C. to 800 ° C. At a temperature lower than 600 ° C., the reaction does not proceed sufficiently. When the temperature is higher than 900 ° C., the orientation deteriorates.
（好適組成の正極活物質シートの製造例）
　Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２粒子を用いた正極活物質シートは、例えば、以下のようにして製造してもよい。先ず、ＮｉＯ粉末とＣｏ３Ｏ４粉末とＡｌＯＯＨ又はＭｎ３Ｏ４粉末とを含有するグリーンシートを形成し、このグリーンシートを１０００℃～１４００℃の範囲内の温度で、大気雰囲気で所定時間焼成することで、（ｈ００）配向した多数の板状の（Ｎｉ，Ｃｏ，Ａｌ）Ｏ又は（Ｎｉ，Ｃｏ，Ｍｎ）Ｏ粒子からなる、独立した膜状のシート（自立膜）が形成される。ここで、助剤としてＭｎＯ２、ＺｎＯ等を添加することにより、粒成長が促進され、結果として板状結晶粒子の（ｈ００）配向性を高めることができる。ここで、「独立した」シートとは、焼成後に他の支持体から独立して単体で取り扱い可能なシートのことをいう。すなわち、「独立した」シートには、焼成により他の支持体（基板等）に固着されて当該支持体と一体化された（分離不能あるいは分離困難となった）ものは含まれない。このように自立膜状に形成されたグリーンシートにおいては、板面方向、すなわち、面内方向（厚さ方向と直交する方向）に比べて、厚さ方向に存在する材料の量がきわめて少ない。このため、厚さ方向に複数個の粒子がある初期段階には、ランダムな方向に粒成長する。一方、粒成長が進み厚さ方向の材料が消費されると、粒成長方向は面内の二次元方向に制限される。これにより、面方向への粒成長が確実に促進される。特に、グリーンシートの厚さが１００μｍ程度もしくはそれ以上と比較的厚めであっても粒成長を可能な限り大きく促進したりすることで、面方向への粒成長がより確実に促進される。すなわち、表面エネルギーの低い面が板面方向、すなわち、面内方向（厚さ方向と直交する方向）と平行な粒子の面方向への粒成長が優先的に促進される。従って、上述のように膜状に形成されたグリーンシートを焼成することで、特定の結晶面が粒子の板面と平行となるように配向した薄板状の多数の粒子が、粒界部にて面方向に結合した自立膜が得られる。すなわち、実質的に厚さ方向についての結晶粒子の個数が１個となるような自立膜が形成される。ここで、「実質的に厚さ方向についての結晶粒子の個数が１個」の意義は、面方向に隣り合う結晶粒子の一部分（例えば端部）が厚さ方向に互いに重なり合うことを排除しない。この自立膜は、上述のような薄板状の多数の粒子が隙間なく結合した、緻密なセラミックスシートとなり得る。上述の工程によって得られた、（ｈ００）配向した（Ｎｉ，Ｃｏ，Ａｌ）Ｏ又は（Ｎｉ，Ｃｏ，Ｍｎ）Ｏセラミックスシートと、硝酸リチウム（ＬｉＮＯ３）とを混合して、所定時間加熱することで、（Ｎｉ，Ｃｏ，Ａｌ）Ｏ又は（Ｎｉ，Ｃｏ，Ｍｎ）Ｏ粒子にリチウムが導入される。これにより、（００３）面が正極板１２から負極層１６の方向に配向し、（１０４）面が板面に沿って配向した膜状の正極板１２用のＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２シート又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２シートが得られる。 (Production example of positive electrode active material sheet of preferred composition)
Li p (Ni x, Co y , Al z) O 2 or Li p (Ni x, Co y , Mn z) positive electrode active material sheet using O 2 particles, for example, be prepared in the following manner Good. First, a green sheet containing NiO powder, Co 3 O 4 powder, and AlOOH or Mn 3 O 4 powder is formed, and the green sheet is fired at a temperature within a range of 1000 ° C. to 1400 ° C. in an air atmosphere for a predetermined time. By doing so, an independent film-like sheet (self-supporting film) composed of a large number of (h00) -oriented (Ni, Co, Al) O or (Ni, Co, Mn) O particles is formed. Here, by adding MnO 2 , ZnO or the like as an auxiliary agent, grain growth is promoted, and as a result, the (h00) orientation of the plate-like crystal grains can be enhanced. Here, the “independent” sheet refers to a sheet that can be handled by itself independently from another support after firing. That is, the “independent” sheet does not include a sheet that is fixed to another support (substrate or the like) by firing and integrated with the support (unseparable or difficult to separate). Thus, in the green sheet formed in a self-supporting film shape, the amount of the material existing in the thickness direction is very small compared to the plate surface direction, that is, the in-plane direction (direction orthogonal to the thickness direction). For this reason, in the initial stage where there are a plurality of grains in the thickness direction, grains grow in random directions. On the other hand, when the grain growth proceeds and the material in the thickness direction is consumed, the grain growth direction is limited to the in-plane two-dimensional direction. This reliably promotes grain growth in the surface direction. In particular, even if the thickness of the green sheet is relatively thick, such as about 100 μm or more, the grain growth in the plane direction is more surely promoted by promoting the grain growth as much as possible. That is, the grain growth in the plane direction of the grains parallel to the plate surface direction, that is, the in-plane direction (direction orthogonal to the thickness direction) is promoted preferentially. Therefore, by firing the green sheet formed in a film shape as described above, a large number of thin plate-like particles oriented so that a specific crystal plane is parallel to the plate surface of the particles are formed at the grain boundary portion. A free-standing film bonded in the plane direction can be obtained. That is, a self-supporting film is formed so that the number of crystal grains in the thickness direction is substantially one. Here, the meaning of “substantially one crystal grain in the thickness direction” does not exclude that a part (for example, end portions) of crystal grains adjacent in the plane direction overlap each other in the thickness direction. This self-supporting film can be a dense ceramic sheet in which a large number of thin plate-like particles as described above are bonded without gaps. The (h00) -oriented (Ni, Co, Al) O or (Ni, Co, Mn) O ceramic sheet obtained by the above process is mixed with lithium nitrate (LiNO 3 ) and heated for a predetermined time. Thus, lithium is introduced into the (Ni, Co, Al) O or (Ni, Co, Mn) O particles. As a result, the (003) plane is oriented in the direction from the positive electrode plate 12 to the negative electrode layer 16, and the (104) plane is oriented along the plate surface for Li p (Ni x , Co y , Mn z) O 2 sheet or Li p (Ni x, Co y , Al z) O 2 sheet is obtained.
　リチウムイオン伝導材料の製造方法
　以下に固体電解質層１４を構成するリチウムイオン伝導材料の代表例の一つである、Ａｌ添加ＬＬＺセラミックス焼結体の好ましい製造方法を説明する。 Method for Producing Lithium Ion Conductive Material A preferred method for producing an Al-added LLZ ceramic sintered body, which is one of the representative examples of the lithium ion conductive material constituting the solid electrolyte layer 14, will be described below.
　先ず、第１焼成工程にて、Ｌｉ成分、Ｌａ成分及びＺｒ成分を含む原料を焼成して、ＬｉとＬａとＺｒと酸素を含むセラミックス合成用の一次焼成粉末を得る。その後、第２焼成工程において、第１焼成工程で得られた一次焼成粉末を焼成して、ＬｉとＬａとＺｒと酸素を含むガーネット型又はガーネット型類似の結晶構造を有するセラミックスを合成する。これにより、ＬＬＺ結晶構造を有し、且つ、アルミニウムを含有してハンドリング可能な焼結性（密度）及び伝導性を備えるセラミックス粉末又は焼結体を容易に得ることができる。 First, in the first firing step, a raw material containing a Li component, a La component and a Zr component is fired to obtain a primary fired powder for ceramic synthesis containing Li, La, Zr and oxygen. Thereafter, in the second firing step, the primary fired powder obtained in the first firing step is fired to synthesize a ceramic having a garnet-type or garnet-like crystal structure containing Li, La, Zr, and oxygen. Thereby, it is possible to easily obtain a ceramic powder or sintered body having a LLZ crystal structure and having sinterability (density) and conductivity that contains aluminum and can be handled.
（Ｌｉ成分、Ｌａ成分及びＺｒ成分）
　これらの各種成分は、特に限定されないで、それぞれの金属成分を含む、金属酸化物、金属水酸化物、金属炭酸塩等、各種金属塩を適宜選択して用いることができる。例えば、Ｌｉ成分としてはＬｉ２ＣＯ３又はＬｉＯＨを用い、Ｌａ成分としてはＬａ（ＯＨ）３又はＬａ２Ｏ３を用い、Ｚｒ成分としてはＺｒＯ２を用いることができる。なお、酸素は、通常、これら構成金属元素を含む化合物の一部を構成する元素として含まれている。セラミックス材料を得るための原料は、各Ｌｉ成分、Ｌａ成分及びＺｒ成分等から固相反応等によりＬＬＺ結晶構造が得られる程度にＬｉ成分、Ｌａ成分及びＺｒ成分を含むことができる。Ｌｉ成分、Ｌａ成分及びＺｒ成分は、ＬＬＺの化学量論組成に従えば、７：３：２あるいは組成比に近似した組成で用いることができる。Ｌｉ成分の消失を考慮する場合には、Ｌｉ成分は、ＬＬＺにおけるＬｉの化学量論に基づくモル比相当量よりも約１０％増量した量を含み、Ｌａ成分及びＺｒ成分は、それぞれＬＬＺモル比に相当する量となるように含有することができる。例えば、Ｌｉ：Ｌａ：Ｚｒのモル比が７．７：３：２となるように、含有することができる。具体的な化合物を用いた場合のモル比としては、Ｌｉ２ＣＯ３：Ｌａ（ＯＨ）３：ＺｒＯ２のとき、約３．８５：約３：約２のモル比となり、Ｌｉ２ＣＯ３：Ｌａ２Ｏ３：ＺｒＯ２のとき、約３．８５：約１．５：約２のモル比となり、ＬｉＯＨ：Ｌａ（ＯＨ）３：ＺｒＯ２のとき、約７．７：約３：約２となり、ＬｉＯＨ：Ｌａ２Ｏ３：ＺｒＯ２のとき、約７．７：約１．５：約２となる。なお、原料粉末の調製にあたっては、公知のセラミックス粉末の合成における原料粉末調製方法を適宜採用することができる。例えば、ライカイ機等や適当なボールミル等に投入して均一に混合することができる。 (Li component, La component and Zr component)
These various components are not particularly limited, and various metal salts such as metal oxides, metal hydroxides, and metal carbonates containing the respective metal components can be appropriately selected and used. For example, Li 2 CO 3 or LiOH can be used as the Li component, La (OH) 3 or La 2 O 3 can be used as the La component, and ZrO 2 can be used as the Zr component. Note that oxygen is usually included as an element constituting a part of a compound containing these constituent metal elements. The raw material for obtaining the ceramic material can contain a Li component, a La component, and a Zr component to such an extent that an LLZ crystal structure can be obtained from each Li component, La component, Zr component, and the like by a solid phase reaction or the like. According to the stoichiometric composition of LLZ, the Li component, La component and Zr component can be used in a composition close to 7: 3: 2 or a composition ratio. When considering the disappearance of the Li component, the Li component includes an amount increased by about 10% from the molar ratio equivalent amount based on the stoichiometry of Li in LLZ, and the La component and the Zr component are each in an LLZ molar ratio. It can contain so that it may become the quantity equivalent to. For example, it can be contained so that the molar ratio of Li: La: Zr is 7.7: 3: 2. When a specific compound is used, the molar ratio is about 3.85: about 3: about 2 when Li 2 CO 3 : La (OH) 3 : ZrO 2 , and Li 2 CO 3 : When La 2 O 3 : ZrO 2 , the molar ratio is about 3.85: about 1.5: about 2, and when LiOH: La (OH) 3 : ZrO 2 is about 7.7: about 3: about 2. When LiOH: La 2 O 3 : ZrO 2 , it is about 7.7: about 1.5: about 2. In preparing the raw material powder, a known raw material powder preparation method in the synthesis of ceramic powder can be appropriately employed. For example, the mixture can be mixed uniformly by putting it into a reiki machine or a suitable ball mill.
（第１焼成工程）
　第１焼成工程は、少なくともＬｉ成分やＬａ成分等の熱分解を行い第２焼成工程でＬＬＺ結晶構造を形成しやくするための一次焼成粉末を得る工程である。一次焼成粉末は、ＬＬＺ結晶構造をすでに有している場合もある。焼成温度は、好ましくは、８５０℃以上１１５０℃以下の温度である。第１焼成工程は、上記温度範囲内において、より低い加熱温度で加熱するステップとより高い加熱温度で加熱するステップとを備えていてもよい。こうした加熱ステップを備えることで、より均一な状態なセラミックス粉末を得ることができ、第２焼成工程によって良質な焼結体を得ることができる。このような複数ステップで第１焼成工程を実施するときには、各焼成ステップ終了後、ライカイ機、ボールミル及び振動ミル等を用いて混練・粉砕することが好ましい。また、粉砕手法は乾式で行うことが望ましい。こうすることで、第２焼成工程により一層均一なＬＬＺ相を得ることができる。第１焼成工程を構成する熱処理ステップは、好ましくは８５０℃以上９５０℃以下の熱処理ステップと１０７５℃以上１１５０℃以下の熱処理ステップを実施することが好ましい。さらに好ましくは８７５℃以上９２５℃以下（約９００℃であることがより好ましい）の熱処理ステップと、１１００℃以上１１５０℃以下（約１１２５℃であることがより好ましい）の熱処理ステップとする。第１焼成工程は、全体で加熱温度として設定した最高温度での加熱時間の合計として１０時間以上１５時間以下程度とすることが好ましい。第１焼成工程を２つの熱処理ステップで構成する場合には、それぞれ最高温度での加熱時間を５～６時間程度とすることが好ましい。一方で、出発原料の１つ又は複数の成分を変更することにより、第１焼成工程を短縮化することができる。例えば、ＬｉＯＨを出発原料に含まれる成分の１つとして用いる場合、ＬＬＺ結晶構造を得るには、Ｌｉ、Ｌａ及びＺｒを含むＬＬＺ構成成分を８５０℃以上９５０℃以下の熱処理ステップで最高温度での加熱時間を１０時間以下にすることができる。これは、出発原料に用いたＬｉＯＨが低温で液相を形成するため、より低温で他の成分と反応しやすくなるからである。 (First firing step)
The first firing step is a step of obtaining a primary fired powder for facilitating the thermal decomposition of at least the Li component and the La component to easily form the LLZ crystal structure in the second firing step. The primary fired powder may already have an LLZ crystal structure. The firing temperature is preferably 850 ° C. or higher and 1150 ° C. or lower. The first baking step may include a step of heating at a lower heating temperature and a step of heating at a higher heating temperature within the above temperature range. By providing such a heating step, a more uniform ceramic powder can be obtained, and a high-quality sintered body can be obtained by the second firing step. When the first firing step is performed in such a plurality of steps, it is preferable to knead and pulverize using a raikai machine, a ball mill, a vibration mill, or the like after the completion of each firing step. Moreover, it is desirable to carry out the pulverization method by a dry method. By doing so, a more uniform LLZ phase can be obtained by the second firing step. The heat treatment step constituting the first firing step is preferably performed by a heat treatment step of 850 ° C. or more and 950 ° C. or less and a heat treatment step of 1075 ° C. or more and 1150 ° C. or less. More preferably, a heat treatment step of 875 ° C. to 925 ° C. (more preferably about 900 ° C.) and a heat treatment step of 1100 ° C. to 1150 ° C. (more preferably about 1125 ° C.) are used. In the first baking step, the total heating time at the maximum temperature set as the heating temperature as a whole is preferably about 10 hours to 15 hours. In the case where the first baking step is composed of two heat treatment steps, it is preferable that the heating time at the maximum temperature is about 5 to 6 hours. On the other hand, the first firing step can be shortened by changing one or more components of the starting material. For example, when LiOH is used as one of the components contained in the starting material, in order to obtain an LLZ crystal structure, an LLZ component containing Li, La and Zr is heated at a maximum temperature in a heat treatment step of 850 ° C. or more and 950 ° C. or less. The heating time can be 10 hours or less. This is because LiOH used as a starting material forms a liquid phase at a low temperature, and thus easily reacts with other components at a lower temperature.
（第２焼成工程）
　第２焼成工程は、第１焼成工程で得られた一次焼成粉末を９５０℃以上１２５０℃以下の温度で加熱する工程とすることができる。第２焼成工程によれば、第１焼成工程で得た一次焼成粉末を焼成し、最終的に複合酸化物であるＬＬＺ結晶構造を有するセラミックスを得ることができる。ＬＬＺ結晶構造を得るには、例えば、Ｌｉ、Ｌａ及びＺｒを含むＬＬＺ構成成分を１１２５℃以上１２５０℃以下の温度で熱処理するようにする。Ｌｉ原料としてＬｉ２ＣＯ３を用いるときには、１１２５℃以上１２５０℃以下で熱処理することが好ましい。１１２５℃未満であるとＬＬＺの単相が得られにくくＬｉ伝導率が小さく、１２５０℃を超えると、異相（Ｌａ２Ｚｒ２Ｏ７等）の形成が見られるようになりＬｉ伝導率が小さく、また結晶成長が著しくなるため、固体電解質としての強度を保つことが難しくなる傾向があるからである。より好ましくは、約１１８０℃から１２３０℃である。一方で、出発原料の１つ又は複数の成分を変更することにより、第２焼成工程を低温化することができる。例えば、Ｌｉ原料としてＬｉＯＨを出発原料に用いる場合、ＬＬＺ結晶構造を得るには、Ｌｉ、Ｌａ及びＺｒを含むＬＬＺ構成成分を９５０℃以上１１２５℃未満の温度でも熱処理することができる。これは、出発原料に用いたＬｉＯＨが低温で液相を形成するため、より低温で他の成分と反応しやすくなるからである。第２焼成工程における上記加熱温度での加熱時間は１８時間以上５０時間以下程度であることが好ましい。時間が１８時間よりも短い場合、ＬＬＺ系セラミックスの形成が十分ではなく、５０時間よりも長い場合、埋め粉を介してセッターと反応しやすくなるほか、結晶成長が著しくサンプルとして強度を保てなくなるからである。好ましくは３０時間以上である。第２焼成工程は、一次焼成粉末を周知のプレス手法を用いて加圧成形して所望の三次元形状（例えば、全固体リチウム電池の固体電解質として使用可能な形状及びサイズ）を付与した成形体とした上で実施することが好ましい。成形体とすることで固相反応が促進されるほか、焼結体を得ることができる。なお、第２焼成工程後に、第２焼成工程で得られたセラミックス粉末を成形体として、第２焼成工程における加熱温度と同様の温度で焼結工程を別途実施してもよい。第２焼成工程で一次焼成粉末を含む成形体を焼成して焼結させる場合、成形体を同じ粉末内に埋没させるようにして実施することが好ましい。こうすることでＬｉの損失を抑制して第２焼成工程前後における組成の変化を抑制できる。なお、原料粉末の成形体は、通常、原料粉末を敷き詰めた上に載置した状態で原料粉末内に埋没される。こうすることで、セッターとの反応を抑制することができる。また、必要に応じて成形体を埋め粉の上下からセッターで押さえ込むことにより、焼結体の焼成時の反りを防止することができる。一方で、第２焼成工程においてＬｉ原料としてＬｉＯＨを用いる等して低温化した場合、一次焼成粉末の成形体を同じ粉末内に埋没させなくても焼結させることができる。これは、第２焼成工程が低温化したことで、Ｌｉの損失が比較的抑制され、またセッターとの反応を抑制することができるからである。 (Second firing step)
A 2nd baking process can be made into the process of heating the primary baking powder obtained at the 1st baking process at the temperature of 950 degreeC or more and 1250 degrees C or less. According to the second firing step, the primary firing powder obtained in the first firing step is fired, and finally a ceramic having an LLZ crystal structure that is a composite oxide can be obtained. In order to obtain the LLZ crystal structure, for example, an LLZ component including Li, La, and Zr is heat-treated at a temperature of 1125 ° C. or higher and 1250 ° C. or lower. When Li 2 CO 3 is used as the Li raw material, it is preferable to perform heat treatment at 1125 ° C. or higher and 1250 ° C. or lower. When the temperature is lower than 1125 ° C., it is difficult to obtain a single phase of LLZ, and the Li conductivity is small. When the temperature exceeds 1250 ° C., formation of a heterogeneous phase (La 2 Zr 2 O 7 or the like) is observed, and the Li conductivity is small. Moreover, since crystal growth becomes remarkable, it tends to be difficult to maintain the strength as a solid electrolyte. More preferably, it is about 1180 to 1230 ° C. On the other hand, the temperature of the second firing step can be lowered by changing one or more components of the starting material. For example, when LiOH is used as a Li raw material as a Li raw material, in order to obtain an LLZ crystal structure, an LLZ constituent component including Li, La, and Zr can be heat-treated at a temperature of 950 ° C. or higher and lower than 1125 ° C. This is because LiOH used as a starting material forms a liquid phase at a low temperature, and thus easily reacts with other components at a lower temperature. The heating time at the heating temperature in the second firing step is preferably about 18 hours or more and 50 hours or less. When the time is shorter than 18 hours, the formation of the LLZ ceramics is not sufficient. When the time is longer than 50 hours, it becomes easy to react with the setter via the filling powder, and the crystal growth is not able to maintain the strength as a sample. Because. Preferably it is 30 hours or more. In the second firing step, the primary fired powder is pressure-molded using a well-known pressing technique to give a desired three-dimensional shape (for example, a shape and size that can be used as a solid electrolyte of an all-solid lithium battery). It is preferable to implement the above. By using a molded body, a solid phase reaction is promoted and a sintered body can be obtained. In addition, you may implement separately a sintering process at the temperature similar to the heating temperature in a 2nd baking process by using the ceramic powder obtained by the 2nd baking process as a molded object after a 2nd baking process. When the molded body containing the primary fired powder is fired and sintered in the second firing step, it is preferable to carry out the process so that the molded body is buried in the same powder. By doing so, the loss of Li can be suppressed and the change in composition before and after the second firing step can be suppressed. In addition, the molded body of the raw material powder is usually buried in the raw material powder in a state where the raw material powder is spread and placed. By carrying out like this, reaction with a setter can be suppressed. Moreover, the curvature at the time of baking of a sintered compact can be prevented by pressing a molded object with a setter from the upper and lower sides of a filling powder as needed. On the other hand, when the temperature is lowered by using LiOH as a Li raw material in the second firing step, the primary fired powder compact can be sintered without being embedded in the same powder. This is because the loss of Li is relatively suppressed and the reaction with the setter can be suppressed by lowering the temperature of the second baking step.
　以上の焼成工程を経た粉末も用いることで、ＬＬＺ結晶構造を有する固体電解質層１４を得ることができる。なお、第１焼成工程及び第２焼成工程のいずれかあるいは双方の工程をアルミニウム（Ａｌ）含有化合物の存在下に実施することにより、結晶構造を有し、且つ、アルミニウムを含有する固体電解質層を製造するようにしてもよい。 The solid electrolyte layer 14 having the LLZ crystal structure can be obtained by using the powder that has undergone the above baking process. The solid electrolyte layer having a crystal structure and containing aluminum is obtained by carrying out either or both of the first firing step and the second firing step in the presence of an aluminum (Al) -containing compound. You may make it manufacture.
　本発明を以下の例によってさらに具体的に説明する。なお、以下の例における正極板及び全固体電池に関する各種パラメータの評価方法は以下のとおりとした。 The present invention will be described more specifically with reference to the following examples. In addition, the evaluation method of the various parameters regarding the positive electrode plate and the all solid state battery in the following examples was as follows.
＜厚さ＞
　正極板を、クロスセクションポリッシャ（ＣＰ）により断面研磨面が観察できるように研磨し、ＳＥＭ（走査型子顕微鏡）（ＪＳＭ－６３９０ＬＡ、日本電子社製）によって断面画像を取得した。得られた断面画像に基づいて正極板の厚さを決定した。 <Thickness>
The positive electrode plate was polished with a cross-section polisher (CP) so that the cross-section polished surface could be observed, and a cross-sectional image was obtained with an SEM (scanning microscope) (JSM-6390LA, manufactured by JEOL Ltd.). The thickness of the positive electrode plate was determined based on the obtained cross-sectional image.
＜相対密度＞
　正極板のサイズ及び厚さに基づいて体積を算出した。また、正極板の重量を測定し、この重量を上記体積で除することにより密度を算出した。この密度を、正極板を構成する物質の真密度（理論密度）で除することにより相対密度を得た。 <Relative density>
The volume was calculated based on the size and thickness of the positive electrode plate. The weight of the positive electrode plate was measured, and the density was calculated by dividing this weight by the above volume. A relative density was obtained by dividing this density by the true density (theoretical density) of the substance constituting the positive electrode plate.
＜配向度＞
　正極板の板面を試料面とし、ＸＲＤ装置（株式会社リガク製、ＴＴＲ－ＩＩＩ）を用いて、Ｘ線回折を２θで１０°から７０°の範囲を２°／ｍｉｎ、ステップ幅０．０２°の条件で行った。得られたＸＲＤプロファイルをロットゲーリング法に従い下記式に基づいて配向度を算出した。
Figure JPOXMLDOC01-appb-M000002
 （上記式中、Ｉは正極板試料の回折強度であり、Ｉ０は無配向の参照試料（正極板試料を乳鉢で粉砕して無配向状態にしたもの）の回折強度である。（ＨＫＬ）は配向度を評価したい回折線であり、（００ｌ）以外の回折線に相当にする。（ｈｋｌ）は全ての回折線に相当する。） <Orientation degree>
The plate surface of the positive electrode plate is used as a sample surface, and an XRD apparatus (manufactured by Rigaku Corporation, TTR-III) is used. It was performed under the condition of °. The degree of orientation of the obtained XRD profile was calculated based on the following formula according to the Lotgering method.
Figure JPOXMLDOC01-appb-M000002
 (In the above formula, I is the diffraction intensity of the positive electrode plate sample, and I 0 is the diffraction intensity of a non-oriented reference sample (a non-oriented state obtained by pulverizing the positive electrode plate sample with a mortar) (HKL). Is a diffraction line for which the degree of orientation is to be evaluated, and corresponds to a diffraction line other than (00l) (hkl) corresponds to all diffraction lines.)
＜表面粗さＲａ＞
　正極板の固体電解質層と接合される側の表面に対して、レーザー顕微鏡（オリンパス社製、ＯＬＳ４０００）を用いて、１３０μｍ×１３０μｍの範囲で表面粗さの測定を行い、正極板表面の算術平均粗さＲａを求めた。 <Surface roughness Ra>
Using a laser microscope (OLS4000, manufactured by Olympus Corporation), the surface roughness of the surface of the positive electrode plate joined to the solid electrolyte layer is measured in the range of 130 μm × 130 μm, and the arithmetic average of the positive electrode plate surface The roughness Ra was determined.
＜抵抗値の上昇率＞
　作製した電池について、ソーラトロン社製の電気化学測定システム（ポテンショ／ガルバノスタッド－周波数応答アナライザ）を用い、周波数１ＭＨｚ～０．１Ｈｚ、電圧１０ｍＶにて交流インピーダンス測定を行い、得られた電池の抵抗値を充放電前の抵抗値とした。次いで、この電池を０．０５Ｃレートの電流値で電池電圧が４．３Ｖとなるまで定電流充電した。その後、電池電圧を４．３Ｖに維持する電流条件で、その電流値が１／２０に低下するまで定電圧充電した。１０分間休止した後、０．０５Ｃレートの電流値で電池電圧が２．５Ｖになるまで定電流放電し、その後１０分間休止した。これらの充放電操作を１サイクルとし、２５℃の条件下で合計３サイクル繰り返した後に、再度交流インピーダンス測定を行なった。充放電後の抵抗値を充放電前の抵抗値で除することで、抵抗値の上昇率とした。 <Rise rate of resistance value>
The produced battery was subjected to AC impedance measurement at a frequency of 1 MHz to 0.1 Hz and a voltage of 10 mV using a Solartron electrochemical measurement system (potentiometer / galvano stud-frequency response analyzer), and the resistance value of the obtained battery was measured. Was the resistance value before charging and discharging. Next, this battery was charged with a constant current at a current value of 0.05 C rate until the battery voltage reached 4.3V. Thereafter, constant voltage charging was performed until the current value decreased to 1/20 under the current condition of maintaining the battery voltage at 4.3V. After resting for 10 minutes, the battery was discharged at a constant current at a current value of 0.05 C until the battery voltage reached 2.5 V, and then rested for 10 minutes. These charging / discharging operations were set as 1 cycle, and after repeating a total of 3 cycles on 25 degreeC conditions, alternating current impedance measurement was performed again. By dividing the resistance value after charging / discharging by the resistance value before charging / discharging, the increase rate of the resistance value was obtained.
　例１～２１
（１）正極板の作製
　表１に示されるモル比で（ＮｉｘＣｏｘＭｎｚ）（ＯＨ）２（式中、ｘ＋ｙ＋ｚ＝１）の組成を有するニッケル・コバルト・マンガン複合水酸化物粉末を用意した。この複合水酸化物粉末は板状一次粒子の配向集合体である。この粉末をボールミルで所定時間（例えば２４時間）粉砕して原料粉末とした。この原料粉末とＬｉＯＨ・Ｈ２Ｏ粉末をＬｉ／（ＮｉｘＣｏｙＭｎｚ）のモル比が１．０５となるように秤量して混合した後、６００℃で３時間仮焼した。得られた粉末１００重量部と、分散媒（トルエン及びイソプロパノールを１：１の重量比で含む混合溶媒）１００重量部と、バインダー（ポリビニルブチラール、ＢＭ－２、積水化学工業株式会社製）１０重量部と、可塑剤（ＤＯＰ（ジ（２－エチルヘキシル）フタレート）、黒金化成株式会社製）４重量部と、分散剤（レオドールＳＰ－Ｏ３０、花王株式会社製）２重量部とを混合した。この混合物を、減圧下で撹拌することで脱泡するとともに、３０００～４０００ｃＰの粘度に調製した。なお、粘度は、ブルックフィールド社製ＬＶＴ型粘度計で測定した。 Examples 1 to 21
(1) Production of Positive Electrode Plate A nickel / cobalt / manganese composite hydroxide powder having a composition of (Ni x Co x Mn z ) (OH) 2 (where x + y + z = 1) in the molar ratio shown in Table 1. Prepared. This composite hydroxide powder is an oriented aggregate of plate-like primary particles. This powder was pulverized with a ball mill for a predetermined time (for example, 24 hours) to obtain a raw material powder. The raw material powder and the LiOH.H 2 O powder were weighed and mixed so that the molar ratio of Li / (Ni x Co y Mn z ) was 1.05, and then calcined at 600 ° C. for 3 hours. 100 parts by weight of the obtained powder, 100 parts by weight of a dispersion medium (a mixed solvent containing toluene and isopropanol at a weight ratio of 1: 1), and 10 parts by weight of a binder (polyvinyl butyral, BM-2, manufactured by Sekisui Chemical Co., Ltd.) Parts, 4 parts by weight of a plasticizer (DOP (di (2-ethylhexyl) phthalate), manufactured by Kurokin Kasei Co., Ltd.) and 2 parts by weight of a dispersant (Rheidol SP-O30, manufactured by Kao Corporation) were mixed. The mixture was degassed by stirring under reduced pressure and adjusted to a viscosity of 3000 to 4000 cP. The viscosity was measured with an LVT viscometer manufactured by Brookfield.
　上述のようにして調製されたスラリーを、ドクターブレード法によって、ＰＥＴフィルムの上に、乾燥後の厚さが６０μｍとなるようにシート状に成形した。得られたシートをＰＥＴフィルムから剥がし、２ｃｍ×２ｃｍとなるように切り取った。切り取ったシートを４００層積層し、積層機にて１２０℃で仮プレスを行ない、グリーンバルクを得た。得られたグリーンバルクを２０℃／ｈで６００℃まで昇温し、６０時間保持し、２０℃／ｈで降温することで脱脂した。得られた脱脂バルクを真空パック後、ＣＩＰにて所定のプレス圧（例えば３ｔ）でプレスした。得られた脱脂バルクを１００℃／ｈで所定の焼成温度（例えば８７５℃）まで大気雰囲気で昇温し、２０時間保持した。得られた焼結バルクを、断面方向が板面となるように、加工により切り出し、板面の表面を研磨することで正極板を得た。得られた正極板を、集電体としてのＡｌ箔上にカーボンを含有した導電性エポキシ接着剤にて接着した。こうして得られた正極板について、厚さ、相対密度、配向度及び表面粗さＲａを前述した方法により測定した。その結果を表１に示す。表１に示されるように例１～２１で作製された正極板は様々な厚さ、相対密度、配向度及び表面粗さＲａを有するが、これらは製造条件を適宜調整することによって任意に付与されたものである（例えば、配向度や相対密度の制御は、原料の粉砕時間、焼成温度、成形時の圧力を適宜調整することにより行った）。 The slurry prepared as described above was formed into a sheet shape on a PET film by a doctor blade method so that the thickness after drying was 60 μm. The obtained sheet was peeled off from the PET film and cut to 2 cm × 2 cm. 400 layers of the cut sheets were laminated and pre-pressed at 120 ° C. with a laminator to obtain a green bulk. The obtained green bulk was heated to 600 ° C. at 20 ° C./h, held for 60 hours, and degreased by lowering the temperature at 20 ° C./h. The obtained degreased bulk was vacuum packed and then pressed with CIP at a predetermined pressing pressure (for example, 3 t). The obtained degreased bulk was heated up to a predetermined firing temperature (for example, 875 ° C.) at 100 ° C./h in an air atmosphere and held for 20 hours. The obtained sintered bulk was cut out by processing so that the cross-sectional direction was the plate surface, and the positive electrode plate was obtained by polishing the surface of the plate surface. The obtained positive electrode plate was bonded to an Al foil as a current collector with a conductive epoxy adhesive containing carbon. About the positive electrode plate obtained in this way, thickness, relative density, orientation degree, and surface roughness Ra were measured by the method mentioned above. The results are shown in Table 1. As shown in Table 1, the positive electrode plates produced in Examples 1 to 21 have various thicknesses, relative densities, orientation degrees, and surface roughness Ra, which are arbitrarily given by appropriately adjusting the production conditions. (For example, the degree of orientation and the relative density were controlled by appropriately adjusting the pulverization time of the raw material, the firing temperature, and the pressure during molding).
（２）固体電解質層の作製
　固体電解質層として、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系固体電解質ＡＤ膜を以下のようにして正極板上に作製した。焼成用原料調製のための各原料成分として、水酸化リチウム（関東化学株式会社）、水酸化ランタン（信越化学工業株式会社）、酸化ジルコニウム（東ソー株式会社）、酸化タンタルを用意した。これらの粉末をＬｉＯＨ：Ｌａ（ＯＨ）３：ＺｒＯ２：Ｔａ２Ｏ５＝７：３：１．６２５：０．１８７５になるように秤量及び配合し、ライカイ機にて混合して焼成用原料を得た。第一の焼成工程として、上記焼成用原料をアルミナ坩堝に入れて大気雰囲気で６００℃／時間にて昇温し９００℃にて６時間保持した。第二の焼成工程として、第一の焼成工程で得られた粉末に対しγ－Ａｌ２Ｏ３を０．６質量％の濃度となるように添加し、この粉末と玉石を混合し振動ミルを用いて３時間粉砕して、出発原料組成がＬｉ７．０Ｌａ３．０Ｚｒ１．６２５Ｔａ０．３７５Ｏ１２Ａｌ０．１の粉末を得た。なお、このγ－Ａｌ２Ｏ３の添加量は、一次焼成粉末が仕込み組成通りの組成を有しているものと想定した組成式Ｌｉ７．０Ｌａ３．０Ｚｒ１．６２５Ｔａ０．３７５Ｏ１２に対するモル比で０．１のＡｌとなる量に相当している。得られた原料粉末をマグネシア製のサヤに入れ、Ａｒ雰囲気中にて８００℃で１時間熱処理して、原料粉末に含有されうるＣＯ２及びＨ２Ｏを除去した。こうして得られた原料粉末は、Ｌｉ及びＯは焼成時の欠損等により仕込み組成のモル数である７及び１２からずれている可能性があるものの、仕込み組成のＬｉ７．０Ｌａ３．０Ｚｒ１．６２５Ｔａ０．３７５Ｏ１２Ａｌ０．１に概ね基づく組成を有し、炭酸リチウムを含まない。 (2) Production of Solid Electrolyte Layer A Li—La—Zr—O-based solid electrolyte AD film was produced as a solid electrolyte layer on the positive electrode plate as follows. Lithium hydroxide (Kanto Chemical Co., Inc.), lanthanum hydroxide (Shin-Etsu Chemical Co., Ltd.), zirconium oxide (Tosoh Corp.), and tantalum oxide were prepared as raw material components for preparing the raw material for firing. These powders are weighed and blended so as to be LiOH: La (OH) 3 : ZrO 2 : Ta 2 O 5 = 7: 3: 1.625: 0.1875, and mixed by a laika machine to be a raw material for firing. Got. As the first firing step, the firing raw material was placed in an alumina crucible, heated at 600 ° C./hour in the air atmosphere, and held at 900 ° C. for 6 hours. As the second firing step, γ-Al 2 O 3 is added to the powder obtained in the first firing step so as to have a concentration of 0.6% by mass, and this powder and cobblestone are mixed to form a vibration mill. And pulverized for 3 hours to obtain a powder having a starting material composition of Li 7.0 La 3.0 Zr 1.625 Ta 0.375 O 12 Al 0.1 . The amount of γ-Al 2 O 3 added is such that the compositional formula Li 7.0 La 3.0 Zr 1.625 Ta 0.375 assumes that the primary fired powder has a composition as charged. This corresponds to an amount of 0.1 Al in molar ratio to O 12 . The obtained raw material powder was put in a magnesia sheath and heat-treated at 800 ° C. for 1 hour in an Ar atmosphere to remove CO 2 and H 2 O that can be contained in the raw material powder. In the raw material powder thus obtained, although Li and O may deviate from 7 and 12, which are the number of moles of the charged composition, due to defects during firing, etc., the charged composition of Li 7.0 La 3.0 Zr It has a composition generally based on 1.625 Ta 0.375 O 12 Al 0.1 and does not contain lithium carbonate.
　熱処理後の原料粉末をＡｒ雰囲気のグローブボックス中で、開口径７５μｍのナイロンメッシュを用いて解砕した後、キャリアガスとしてＮ２ガスを用いてエアロゾルデポジション（ＡＤ）法により成膜を行った。このＡＤ成膜は、図２に示されるような成膜装置２０を用いて行った。図２に示される成膜装置２０は、大気圧より低い気圧の雰囲気下で原料粉末を基板上に噴射するＡＤ法に用いられる装置として構成されている。この成膜装置２０は、原料成分を含む原料粉末のエアロゾルを生成するエアロゾル生成部２２と、原料粉末を基板２１に噴射して原料成分を含む膜を形成する成膜部３０とを備えている。エアロゾル生成部２２は、原料粉末を収容し図示しないガスボンベからのキャリアガスの供給を受けてエアロゾルを生成するエアロゾル生成室２３と、生成したエアロゾルを成膜部３０へ供給する原料供給管２４と、エアロゾル生成室２３及びその中のエアロゾルに１０～１００Ｈｚの振動数で振動が付与する加振器２５とを備えている。成膜部３０は、基板２１にエアロゾルを噴射する成膜チャンバ３２と、成膜チャンバ３２の内部に配設され基板２１を固定する基板ホルダ３４と、基板ホルダ３４をＸ軸－Ｙ軸方向に移動するＸ－Ｙステージ３３とを備えている。また、成膜部３０は、先端にスリット３７が形成されエアロゾルを基板２１へ噴射する噴射ノズル３６と、成膜チャンバ３２を減圧する真空ポンプ３８とを備えている。この成膜装置２０は、成膜チャンバ３２内に加熱装置や耐熱部材等を設けて原料粉末を加熱できるように構成されてもよい。例えば、原料粉末が単結晶化する温度での加熱処理を行えるように石英ガラスやセラミックス等の耐熱部材を用いてもよい。成膜装置２０による固体電解質膜の作製条件は以下のとおりとした。基板としては、先に合成した正極板を用いた。また、キャリアガスとして流量２Ｌ／ｍｉｎの酸素ガスを使用し、成膜チャンバ内の圧力が０．１～０．２ｋＰａ、エアロゾル化室の圧力を５０～７０ｋＰａになるように調整して、成膜を行った。その際、ノズルの開口サイズは１０ｍｍ×１．８ｍｍとし、ノズルの短辺方向に走査距離１０ｍｍ、走査速度５ｍｍ／ｓｅｃで６０往復分、成膜と同時に走査させた。こうして、厚さ２μｍのＬｉ－Ｌａ－Ｚｒ－Ｏ系固体電解質ＡＤ膜を正極板上に形成した。 The raw material powder after the heat treatment was crushed in a glove box under an Ar atmosphere using a nylon mesh having an opening diameter of 75 μm, and then deposited by an aerosol deposition (AD) method using N 2 gas as a carrier gas. . This AD film formation was performed using a film formation apparatus 20 as shown in FIG. A film forming apparatus 20 shown in FIG. 2 is configured as an apparatus used for the AD method in which a raw material powder is injected onto a substrate in an atmosphere at a pressure lower than atmospheric pressure. The film forming apparatus 20 includes an aerosol generating unit 22 that generates an aerosol of a raw material powder containing a raw material component, and a film forming unit 30 that sprays the raw material powder onto a substrate 21 to form a film containing the raw material component. . The aerosol generation unit 22 contains a raw material powder, receives an supply of a carrier gas from a gas cylinder (not shown), generates an aerosol, a raw material supply pipe 24 that supplies the generated aerosol to the film forming unit 30, and An aerosol generation chamber 23 and a vibrator 25 for applying vibration to the aerosol in the chamber at a frequency of 10 to 100 Hz are provided. The film forming unit 30 includes a film forming chamber 32 for injecting aerosol onto the substrate 21, a substrate holder 34 disposed in the film forming chamber 32 for fixing the substrate 21, and the substrate holder 34 in the X-axis-Y-axis directions. And an XY stage 33 that moves. The film forming unit 30 includes a spray nozzle 36 that has a slit 37 formed at the tip thereof and sprays aerosol onto the substrate 21, and a vacuum pump 38 that decompresses the film forming chamber 32. The film forming apparatus 20 may be configured to heat the raw material powder by providing a heating device, a heat-resistant member, or the like in the film forming chamber 32. For example, a heat-resistant member such as quartz glass or ceramics may be used so that heat treatment can be performed at a temperature at which the raw material powder is single-crystallized. The production conditions of the solid electrolyte membrane by the film forming apparatus 20 were as follows. As the substrate, the previously synthesized positive electrode plate was used. In addition, oxygen gas having a flow rate of 2 L / min is used as a carrier gas, and the pressure in the deposition chamber is adjusted to 0.1 to 0.2 kPa and the pressure in the aerosol chamber is adjusted to 50 to 70 kPa. Went. At that time, the opening size of the nozzle was set to 10 mm × 1.8 mm, and scanning was performed simultaneously with the film formation for 60 reciprocations at a scanning distance of 10 mm and a scanning speed of 5 mm / sec in the short side direction of the nozzle. In this way, a Li—La—Zr—O-based solid electrolyte AD film having a thickness of 2 μm was formed on the positive electrode plate.
（３）全固体リチウム電池の組み立て
　イオンスパッタリング装置（日本電子製、ＪＦＣ－１５００）を用いたスパッタリングにより、固体電解質層上に厚さ５００ÅのＡｕ膜を形成した。得られたＡｕ膜上に、Ａｒ雰囲気のグローブボックス中で、Ｌｉ金属箔、及び集電層としてのＣｕ箔を載置し、２００℃のホットプレート上にて加圧圧着した。こうして得られた素子をラミネートパックして、全固体リチウム電池パックを得た。 (3) Assembly of all solid lithium battery An Au film having a thickness of 500 mm was formed on the solid electrolyte layer by sputtering using an ion sputtering apparatus (manufactured by JEOL, JFC-1500). On the obtained Au film, a Li metal foil and a Cu foil as a current collecting layer were placed in a glove box in an Ar atmosphere, and pressure-bonded on a hot plate at 200 ° C. The device thus obtained was laminated and a full solid lithium battery pack was obtained.
　例２２～２５
　原料粉末としてニッケル・コバルト・マンガン複合水酸化物粉末を用いる代わりに、表１に示されるモル比となるように（ＮｉｘＣｏｙ）（ＯＨ）２の組成を有するニッケル・コバルト複合水酸化物粉末とＡｌＯＯＨ（ＳＡＳＯＬ社製）粉末とを秤量して得た混合粉末を用いたこと、及び脱脂バルクの焼成を酸素雰囲気にて７７５℃で２０時間保持することにより行ったこと以外は、例１～２１と同様の基本手順にて全固体リチウム電池の作製及び各種評価を行った。なお、このニッケル・コバルト複合水酸化物粉末は板状一次粒子の配向集合体である。結果は表１に示されるとおりであった。 Examples 22-25
Instead of using nickel-cobalt-manganese composite hydroxide powder as the raw material powder, nickel-cobalt composite hydroxide having a composition of (Ni x Co y ) (OH) 2 so as to have the molar ratio shown in Table 1 Example 1 except that a mixed powder obtained by weighing powder and AlOOH (made by SASOL) was used, and that the degreasing bulk was fired by holding at 775 ° C. for 20 hours in an oxygen atmosphere. All-solid lithium batteries were prepared and evaluated in the same basic procedure as in -21. The nickel / cobalt composite hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 1.
　例２６～２８
　原料粉末としてニッケル・コバルト・マンガン複合水酸化物粉末を用いる代わりに、水酸化コバルト（Ｃｏ（ＯＨ）２）粉末を用いたこと以外は、例１～２１と同様の基本手順にて全固体リチウム電池の作製及び各種評価を行った。なお、この水酸化コバルト粉末は板状一次粒子の配向集合体である。結果は表１に示されるとおりであった。 Examples 26-28
All solid lithium was obtained by the same basic procedure as in Examples 1 to 21 except that cobalt hydroxide (Co (OH) 2 ) powder was used instead of nickel / cobalt / manganese composite hydroxide powder as raw material powder. Battery preparation and various evaluations were performed. The cobalt hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 1.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　例２９～３４
　固体電解質層として、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系固体電解質ＡＤ膜の代わりに、ＬｉＰＯＮ系固体電解質スパッタ膜を以下のようにして作製したこと以外は、例１～２１と同様の基本手順にて全固体リチウム電池の作製及び各種評価を行った。結果は表２に示されるとおりであった。 Examples 29-34
The same basic procedure as in Examples 1 to 21, except that a LiPON-based solid electrolyte sputtered film was prepared as follows instead of the Li-La-Zr-O-based solid electrolyte AD film as the solid electrolyte layer. An all-solid lithium battery was prepared and subjected to various evaluations. The results were as shown in Table 2.
（ＬｉＰＯＮ系固体電解質スパッタ膜の作製）
　直径４インチ（約１０ｃｍ）のリン酸リチウム焼結体ターゲットを準備した。このターゲットを用いてスパッタリング装置（キャノンアネルバ製、ＳＰＦ－４３０Ｈ）を用いてＲＦマグネトロン方式にてガス種Ｎ２を０．２Ｐａ、出力０．２ｋＷにて膜厚１μｍとなる様にスパッタリングを行なった。こうして、厚さ１μｍのＬｉＰＯＮ系固体電解質スパッタ膜を正極板上に形成した。 (Preparation of LiPON-based solid electrolyte sputtered film)
A lithium phosphate sintered compact target having a diameter of 4 inches (about 10 cm) was prepared. Using this target, sputtering was performed using a sputtering apparatus (SPF-430H, manufactured by Canon Anelva) with an RF magnetron method so that the gas type N 2 was 0.2 Pa, the output was 0.2 kW, and the film thickness was 1 μm. . Thus, a LiPON-based solid electrolyte sputtered film having a thickness of 1 μm was formed on the positive electrode plate.
　例３５
　原料粉末としてニッケル・コバルト・マンガン複合水酸化物粉末を用いる代わりに、表２に示されるモル比となるように（ＮｉｘＣｏｙ）（ＯＨ）２の組成を有するニッケル・コバルト複合水酸化物粉末とＡｌＯＯＨ（ＳＡＳＯＬ社製）粉末とを秤量して得た混合粉末を用いたこと、及び脱脂バルクの焼成を酸素雰囲気にて７７５℃で２０時間保持することにより行ったこと以外は、例２９～３４と同様の基本手順にて全固体リチウム電池の作製及び各種評価を行った。なお、このニッケル・コバルト複合水酸化物粉末は板状一次粒子の配向集合体である。結果は表２に示されるとおりであった。 Example 35
Instead of using nickel-cobalt-manganese composite hydroxide powder as a raw material powder, nickel-cobalt composite hydroxide having a composition of (Ni x Co y ) (OH) 2 so as to have a molar ratio shown in Table 2 Example 29, except that a mixed powder obtained by weighing powder and AlOOH (manufactured by SASOL) was used, and that the degreasing bulk was fired by holding at 775 ° C. for 20 hours in an oxygen atmosphere. All-solid lithium batteries were prepared and evaluated in the same basic procedure as in .about.34. The nickel / cobalt composite hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 2.
　例３６
　原料粉末としてニッケル・コバルト・マンガン複合水酸化物粉末を用いる代わりに、水酸化コバルト（Ｃｏ（ＯＨ）２）粉末を用いたこと以外は、例２９～３４と同様の基本手順にて全固体リチウム電池の作製及び各種評価を行った。なお、この水酸化コバルト粉末は板状一次粒子の配向集合体である。結果は表２に示されるとおりであった。 Example 36
All solid lithium was prepared in the same basic procedure as in Examples 29 to 34 except that cobalt hydroxide (Co (OH) 2 ) powder was used instead of nickel / cobalt / manganese composite hydroxide powder as raw material powder. Battery preparation and various evaluations were performed. The cobalt hydroxide powder is an oriented aggregate of plate-like primary particles. The results were as shown in Table 2.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004

Claims (10)

  1. 　１０μｍ以上の厚さ及び１５～８５％の配向度を有する配向多結晶体からなる正極板であって、該配向多結晶体が、Ｌｉｐ（Ｎｉｘ，Ｃｏｙ，Ｍｎｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０＜ｘ＜０．８、０＜ｙ＜１、０≦ｚ≦０．７、ｘ＋ｙ＋ｚ＝１）又はＬｉｐ（Ｎｉｘ，Ｃｏｙ，Ａｌｚ）Ｏ２（式中、０．９≦ｐ≦１．３、０．６＜ｘ＜０．９、０．１＜ｙ≦０．３、０≦ｚ≦０．２、ｘ＋ｙ＋ｚ＝１）で表される基本組成の層状岩塩構造を有する複数のリチウム遷移金属酸化物粒子からなる、正極板と、
    　前記正極板上に設けられ、Ｌｉ－Ｌａ－Ｚｒ－Ｏ系セラミックス材料及び／又はリン酸リチウムオキシナイトライド（ＬｉＰＯＮ）系セラミックス材料で構成される固体電解質層と、
    　前記固体電解質層上に設けられる負極層と、
    を備えた、全固体リチウム電池。     A positive electrode plate made of an oriented polycrystal having a thickness of 10 μm or more and an orientation degree of 15 to 85%, wherein the oriented polycrystal is Li p (Ni x , Co y , Mn z ) O 2 (formula Medium, 0.9 ≦ p ≦ 1.3, 0 <x <0.8, 0 <y <1, 0 ≦ z ≦ 0.7, x + y + z = 1) or Li p (Ni x , Co y , Al z ) O 2 (where 0.9 ≦ p ≦ 1.3, 0.6 <x <0.9, 0.1 <y ≦ 0.3, 0 ≦ z ≦ 0.2, x + y + z = 1) A positive electrode plate comprising a plurality of lithium transition metal oxide particles having a layered rock salt structure of the basic composition represented;
    A solid electrolyte layer provided on the positive electrode plate and composed of a Li—La—Zr—O based ceramic material and / or a lithium phosphate oxynitride (LiPON) based ceramic material;
    A negative electrode layer provided on the solid electrolyte layer;
    An all-solid-state lithium battery.
  2. 　前記配向度が４５～７５％である、請求項１に記載の全固体リチウム電池。 The all-solid-state lithium battery according to claim 1, wherein the degree of orientation is 45 to 75%.
  3. 　前記正極板の前記固体電解質層側の表面が０．０５μｍより大きく３．０μｍ未満の算術平均粗さＲａを有する、請求項１又は２に記載の全固体リチウム電池。 The all-solid-state lithium battery according to claim 1 or 2, wherein the surface of the positive electrode plate on the solid electrolyte layer side has an arithmetic average roughness Ra of more than 0.05 µm and less than 3.0 µm.
  4. 　前記正極板の前記固体電解質層側の表面が０．１～２．０μｍの算術平均粗さＲａを有する、請求項１～３のいずれか一項に記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 3, wherein the surface of the positive electrode plate on the solid electrolyte layer side has an arithmetic average roughness Ra of 0.1 to 2.0 µm.
  5. 　前記配向多結晶体が７５～９９．９０％の相対密度を有する、請求項１～４のいずれか一項に記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 4, wherein the oriented polycrystal has a relative density of 75 to 99.90%.
  6. 　前記配向多結晶体が９５～９９．８５％の相対密度を有する、請求項１～５のいずれか一項に記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 5, wherein the oriented polycrystal has a relative density of 95 to 99.85%.
  7. 　前記配向多結晶体が１００μｍ未満の厚さを有する、請求項１～６のいずれか一項に記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 6, wherein the oriented polycrystal has a thickness of less than 100 µm.
  8. 　前記配向多結晶体が１５～６０μｍの厚さを有する、請求項１～７のいずれか一項に記載のに記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 7, wherein the oriented polycrystal has a thickness of 15 to 60 µm.
  9. 　前記複数のリチウム遷移金属酸化物粒子が、前記層状岩塩構造の（００３）面が前記正極板の板面と交差するような方向に配向されてなる、請求項１～８のいずれか一項に記載の全固体リチウム電池。 The plurality of lithium transition metal oxide particles are oriented in a direction such that the (003) plane of the layered rock salt structure intersects the plate surface of the positive electrode plate. All-solid lithium battery as described.
  10. 　正極集電体及び／又は負極集電体をさらに備えた、請求項１～９のいずれか一項に記載の全固体リチウム電池。 The all-solid-state lithium battery according to any one of claims 1 to 9, further comprising a positive electrode current collector and / or a negative electrode current collector.
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