WO2020189705A1 - Lithium-containing oxide crystal, battery and method for producing lithium-containing oxide crystal - Google Patents

Lithium-containing oxide crystal, battery and method for producing lithium-containing oxide crystal Download PDF

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WO2020189705A1
WO2020189705A1 PCT/JP2020/011916 JP2020011916W WO2020189705A1 WO 2020189705 A1 WO2020189705 A1 WO 2020189705A1 JP 2020011916 W JP2020011916 W JP 2020011916W WO 2020189705 A1 WO2020189705 A1 WO 2020189705A1
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lithium
containing oxide
oxide crystal
crystal
cracks
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PCT/JP2020/011916
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French (fr)
Japanese (ja)
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悠宗 石田
智紀 有賀
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アダマンド並木精密宝石株式会社
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Priority to CN202080019417.6A priority Critical patent/CN113544317A/en
Priority to JP2021507388A priority patent/JP7572730B2/en
Publication of WO2020189705A1 publication Critical patent/WO2020189705A1/en

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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/34—Edge-defined film-fed crystal-growth using dies or slits
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/22—Complex oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a lithium-containing oxide crystal, a battery, and a method for producing a lithium-containing oxide crystal.
  • lithium-ion batteries have been used for batteries for smartphones and batteries for electric vehicles.
  • an electrolytic solution is used as an electrolyte in which Li (lithium) ions can move.
  • Li (lithium) ions can move.
  • an all-solid-state battery that uses a solid electrolyte instead of an electrolytic solution is being developed.
  • the solid electrolyte used in the all-solid-state lithium-ion battery include sulfide-based and oxide-based lithium-ion crystals.
  • the sulfide-based solid electrolyte is suitable for a battery having high Li ion conductivity and emphasizing energy density.
  • harmful substances hydrogen sulfide (H 2 S)
  • H 2 S hydrogen sulfide
  • the oxide-based solid electrolyte has a problem that the Li ion conductivity is lower than that of the sulfide-based solid electrolyte.
  • an oxide-based solid electrolyte having a conductivity of 10 -3 (S / cm) or more at room temperature is desirable.
  • an oxide-based solid electrolyte exhibiting a conductivity of about 10 -3 (S / cm) for example, lithium-containing oxide crystals such as perovskite type La 0.51 Li 0.34 TiO 2.94 are known ( For example, see Non-Patent Document 1).
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a lithium-containing oxide crystal having a large area without cracks, and also to provide a method for producing the lithium-containing oxide crystal. Another object of the present invention is to provide a battery including at least a part of the lithium-containing oxide crystal.
  • the lithium-containing oxide crystal of the present invention is characterized by having no cracks, having a cross section of 0.38 cm 2 or more, and containing oxygen.
  • the lithium-containing oxide crystal of the present invention has a large area without cracks, so that the capacity and conductivity of the all-solid-state battery can be increased.
  • the cross-sectional area is 1.76 cm 2 or more 100 cm 2 or less.
  • it has a dimension in the longitudinal direction, and the dimension in the longitudinal direction is 10 mm or more.
  • the battery of the present invention is characterized in that at least a part of the lithium-containing oxide crystals described in any one of the above is used.
  • the method for producing a lithium-containing oxide crystal of the present invention includes a melted portion forming step of melting at least a part of an oxygen-containing lithium-containing oxide crystal raw material to form a melted portion. It has a growth step of growing and forming lithium-containing oxide crystals from the molten portion, and the dew point of the atmosphere in the growth step is in the range of ⁇ 70 ° C. or higher and ⁇ 35 ° C. or lower, and the lithium-containing oxide crystal is 0.38 cm. It is characterized by having a cross-sectional area of 2 or more.
  • the growth of the lithium-containing oxide crystal having an area of from the molten portion 1.76 cm 2 or more 100 cm 2 or less Form.
  • the dew point is set within the range of ⁇ 65 ° C. or higher and ⁇ 45 ° C. or lower, and the lithium-containing oxide crystal is grown and formed at a dimension in the longitudinal direction of 10 mm or more from the molten portion.
  • the CZ method or the EFG method is used for the growth step.
  • the present invention it is possible to provide a lithium-containing oxide crystal having a large area without cracks and a method for producing the same. Further, it is possible to provide a battery including at least a part of the lithium-containing oxide crystal.
  • the first feature of the present embodiment is that the lithium-containing oxide crystal has no cracks, has a cross section of 0.38 cm 2 or more, and contains oxygen.
  • the second feature is that the cross-sectional area was 1.76 cm 2 or more 100 cm 2 or less.
  • the third feature is that it has a longitudinal dimension, and the longitudinal dimension is 10 mm or more.
  • the fourth feature is that the battery uses at least a part of the lithium-containing oxide crystals described in any one of the above.
  • the fifth feature is that the method for producing a lithium-containing oxide crystal is a melt portion forming step of melting at least a part of an oxygen-containing lithium-containing oxide crystal raw material to form a melt portion, and a lithium-containing oxidation from the melt portion. It has a growth step of growing and forming a physical crystal, the dew point of the atmosphere in the growth step is in the range of -70 ° C or higher and -35 ° C or lower, and the lithium-containing oxide crystal has a cross-sectional area of 0.38 cm 2 or more. That is.
  • the seventh feature is that the dew point is set within the range of -65 ° C or higher and -45 ° C or lower, and lithium-containing oxide crystals are grown and formed in the longitudinal dimension of 10 mm or more from the molten portion.
  • the eighth feature is that the CZ method or the EFG method is used for the growth process.
  • the crack includes oxygen has no 0.38 cm 2 or more cross-sectional area, the general formula Li 7-x-y La 3 Zr 2-x-y Nb x Ta y O It is represented by 12 (0.2 ⁇ x + y ⁇ 1.0, 0 ⁇ x ⁇ 1.0, 0 ⁇ y ⁇ 1.0) and has a cubic garnet-type structure. More preferably, in the range sectional area of 1.76 cm 2 or more 100 cm 2 or less. Further, the lithium-containing oxide crystal has a dimension in the longitudinal direction, and the dimension in the longitudinal direction is preferably 10 mm or more.
  • the lithium-containing oxide crystal has no cracks and has a large area and volume, it is possible to improve productivity, increase the capacity of the all-solid-state battery, and increase the conductivity.
  • the high conductivity means that the conductivity of the solid electrolyte inside the battery is, for example, 0.5 (mS / cm) or more.
  • the crack refers to a crack that can be confirmed with an optical microscope and exceeds 1 mm among the cracks generated in the lithium-containing oxide crystal.
  • the lithium-containing oxide crystal having no cracks it is preferable that there are no cracks in the entire crystal in as-grown immediately after crystal growth, but it also includes a case where a region without cracks is partially formed. Further, the case where cracks are removed by polishing or cutting the surface after crystal growth is also included.
  • the crack-free cross-sectional area means the area of the lithium ion oxide crystal in the direction in which the crack-free region is maximized, but is the cross-sectional area in the plane perpendicular to the crystal growth direction. Is preferable because the crystal quality in the plane can be made uniform.
  • FIG. 1 is a cross-sectional observation photograph showing a lithium-containing oxide crystal and cracks formed in the crystal.
  • the scale shown in the lower part of FIG. 1 is 1 mm
  • the lithium-containing oxide crystal shown in the figure has a disk shape having a diameter of about 7 mm.
  • FIG. 1 when the lithium-containing oxide crystal is cut in a plane perpendicular to the growth direction, it can be seen that a plurality of cracks extend from the outer periphery of the crystal toward the inside.
  • problems such as a decrease in reliability, a decrease in capacity, and a decrease in life may occur when used in an all-solid-state battery, which is not preferable.
  • a lithium-containing oxide crystal having no cracks within a diameter of about 7 mm has a cross section of 0.38 cm 2 or more, and the capacity and conductivity of the all-solid-state battery should be increased. Can be done.
  • various raw materials of lithium-containing oxide crystals are prepared as a raw material preparation step, crushed and mixed at a predetermined ratio to process the raw materials into powder.
  • the method of pulverization and mixing is not limited, and known methods can be used.
  • the powdered raw material is pressure-molded and fired to obtain a raw material sintered body.
  • the methods of pressure molding and firing are not limited, and known methods can be used.
  • a lithium compound, a lanthanum compound, a zirconium compound, a tantalum compound, and a niobium compound can be used as a raw material for the lithium-containing oxide crystal.
  • the lithium compound include Li 2 O and Li 2 CO 3 .
  • the lanthanum compound include La 2 O 3 and La (OH) 3 .
  • the zirconium compound include ZrO 2 , ZrC l4 , La 2 Zr 2 O 7 , Li 2 ZrO 3, and the like.
  • the tantalum compound include Ta 2 O 5 and Ta C l 5 .
  • the niobium compound include Nb 2 O 5 , LiNbO 3 , and LaNbO 4 .
  • the method of the molten portion forming step and the growing step is not limited, and the crystal can be grown by using various known melting methods.
  • the FZ (Floating Zone) method the Bridgeman method, the kiloporous method, and the TSSG (Top Edged Solution).
  • the Growth includes the Growth) method, the LPE (Liquid Phase Epitaxy) method, the CZ (Czochralski) method, and the EFG (Edge-defined Film-fed Growth) method.
  • the CZ method In order to increase the diameter of the lithium-containing oxide crystal, it is preferable to use the CZ method or the EFG method. In the case of a growth method using a crucible, it is preferable to use Ir, which does not react with the raw material melt, as a material for the crucible.
  • the atmosphere used in the growth step is preferably N 2 or Ar, and dry air, and the dew point of the atmosphere is in the range of ⁇ 70 ° C. or higher and ⁇ 35 ° C. or lower.
  • the dew point of the atmosphere means a temperature at which the amount of water vapor contained in the atmosphere becomes the saturated water vapor amount at the same atmospheric pressure.
  • a capacitance type dew point meter online dew point meter TK-100 manufactured by Tekne Corporation was used for measuring the dew point of the atmosphere.
  • the Li content contained in the crystal changes depending on the dew point of the atmosphere in the growth process, and cracks occur.
  • white turbidity and cracks occur in the appearance as the Li content changes, and the characteristics in the crystal vary.
  • the dew point of the atmosphere in the growth process to the range of -70 ° C or higher and -35 ° C or lower, white turbidity and cracks are suppressed and variation in characteristics is suppressed, and a uniform lithium content having a cross section of 0.38 cm 2 or more is contained. Oxide crystals can be obtained.
  • the dew point of the atmosphere in the growth step in the range of -70 ° C. or higher -40 °C less, grown form a lithium-containing oxide crystal having an area of 1.76 cm 2 or more 100 cm 2 or less from the molten portion be able to. Further, by setting the dew point of the atmosphere in the growth step within the range of -65 ° C. or higher and -45 ° C. or lower, the dimension in the longitudinal direction of 10 mm or more from the molten portion (that is, the length in the growth direction of the lithium-containing oxide crystal). ) Can grow and form lithium-containing oxide crystals.
  • Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 which is a lithium-containing oxide crystal was grown by using the FZ method.
  • the amount of Li contained in the raw material was 108% of Li contained in the obtained lithium-containing oxide crystal.
  • air (dry air) at room temperature of 1 atm was flowed at a flow rate of 7 liters per minute, and the dew points of Examples 1 and 2 and Comparative Example 1 were ⁇ 35 ° C., ⁇ 55 ° C., and ⁇ , respectively.
  • the condition was set to 20 ° C.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 2 is a table showing evaluations of Examples 1 and 2 and Comparative Example 1 of lithium-containing oxide crystals grown by the FZ method.
  • the area column in FIG. 2 shows the cross-sectional area in the non-cracked portion, and the length column shows the length in the growth direction of the non-cracked portion having a cross-sectional area of 0.38 cm 2 or more.
  • There is. 3 (a) to 3 (c) are photographs showing the appearance of the lithium-containing oxide crystals of Examples 1 and 2, respectively.
  • the left side in FIGS. 3 (a) to 3 (c) is the start side of crystal growth, and the state of as-grown in which the raw material is melted and grown is shown toward the right side.
  • Example 1 As shown in FIGS. 2 and 3, in Example 1, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 10 mm, and no crack was generated in the region. Further, in Example 2, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 existed in an area of 40 mm, and no crack was generated in the region. On the other hand, in Comparative Example 1, there were cracks on the entire surface of the lithium-containing oxide crystal, and there was no region not containing the cracks. Therefore, when the dew point is larger than ⁇ 35 ° C., it can be seen that a lithium-containing oxide crystal having a cross section of 0.38 cm 2 or more and without cracks cannot be obtained. (Examples 3 to 6 and Comparative Example 2)
  • Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 which is a lithium-containing oxide crystal
  • the amount of Li contained in the raw material was 108% of Li contained in the obtained lithium-containing oxide crystal.
  • the atmosphere during the growth process was such that 1 atm of air (dry air) was flowed at a flow rate of 7 liters per minute at room temperature, and the dew points of Examples 3 to 6 and Comparative Example 2 were ⁇ 40 ° C., ⁇ 43 ° C., and ⁇ , respectively.
  • the conditions were set at 48 ° C., ⁇ 62 ° C., and ⁇ 68 ° C.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 4 is a table showing external photographs of lithium-containing oxide crystals of Examples 3 to 6 and Comparative Example 2 grown by using the FZ method under different dew point conditions.
  • a dew point of ⁇ 40 ° C. is Example 3
  • a dew point of ⁇ 43 ° C. is Example 4
  • a dew point of ⁇ 48 ° C. is Example 5
  • a dew point of ⁇ 62 ° C. is Example 6
  • a dew point of ⁇ 68 ° C. is Comparative Example 2.
  • a region having a cross section of 0.38 cm 2 existed, and no crack was generated in the region.
  • Example 3 white turbidity was partially generated due to lack of Li, and the cross section was 0.38 cm 2 or more and the crack-free region was less than 10 mm. Further, also in Example 4, the cross section was 0.38 cm 2 or more and the region without cracks was less than 10 mm. Therefore, it can be seen that by setting the dew point within the range of ⁇ 65 ° C. or higher and ⁇ 45 ° C. or lower, a region having a cross section of 0.38 cm 2 or more and no cracks can be formed with a size of 10 mm or more. (Examples 7 to 10)
  • Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 and Li 6.5 La 3 Zr 1.5 which are lithium-containing oxide crystals, are used.
  • Nb 0.25 Ta 0.25 O 12 was grown.
  • N 2 at 1 atm at room temperature was flowed at a flow rate of 2 to 4 liters per minute, and the dew points of Examples 7 to 10 were ⁇ 40 ° C., ⁇ 65 ° C., ⁇ 66 ° C., and ⁇ 69, respectively.
  • the condition was set to °C.
  • Ir material was used for the crucible.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 5 is a table showing the evaluation of Examples 7 to 10 of the lithium-containing oxide crystals grown by the CZ method.
  • the area column in FIG. 5 shows the cross-sectional area in the non-cracked portion, and the length column shows the length in the growth direction of the non-cracked portion having a cross-sectional area of 0.38 cm 2 or more.
  • Examples 7, 8 and 10 have Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12
  • Example 9 has Li 6.5 La 3 Zr 1.5 Nb 0.25 containing Ta. It is Ta 0.25 O 12 .
  • 6 (a) to 6 (d) are photographs showing the appearance of the lithium-containing oxide crystals of Examples 7 to 10, respectively.
  • the left side in FIGS. 6 (a) to 6 (d) is the start side of crystal growth, and the state of as-grown in which the raw material is melted and grown is shown toward the right side.
  • Example 7 a crack-free region having a diameter of 18 mm and a cross section of 2.76 cm 2 was formed in the initial stage of growth, and cracks were formed when the cross section was 0.38 cm 2 or more. There was also a portion of 11 mm in which was not generated. Further, in Example 8, a crack-free region having a diameter of 15 mm and a cross section of 1.77 cm 2 was formed, and a portion having a cross section of 0.38 cm 2 or more and no cracks was also present at 38 mm.
  • Example 9 a crack-free region having a diameter of 9.6 mm and a cross section of 0.72 cm 2 was formed, and there was a portion having a cross section of 0.38 cm 2 or more and no cracks of 27 mm. .. Further, in Example 10, although cracks were partially generated, a crack-free region having a diameter of 16 mm and a cross section of 2.0 cm 2 was formed, and cracks were not generated when the cross section was 0.38 cm 2 or more. The part was also present at 24 mm.
  • the lithium-containing oxide crack no cross-sectional area has an area of 1.76 cm 2 or more 100 cm 2 or less crystals are obtained .. (Example 11)
  • Example 11 a lithium-containing oxide crystal, Li 6.8 La 3 Zr 1.8 Nb 0.2 O 12, was grown using the CZ method.
  • the atmosphere during the growth process was set to a dew point of ⁇ 65 ° C. by flowing N 2 at room temperature at a flow rate of 2 to 4 liters per minute. Ir material was used for the crucible.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 7 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 11.
  • the right side in FIG. 7 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the left side.
  • a crack-free region is formed with a diameter of 9.5 mm and a cross section of 0.70 cm 2 , and a portion having a cross section of 0.38 cm 2 or more and no cracks. Also existed in the longitudinal dimension (length in the growth direction) of 30 mm.
  • Example 12 a lithium-containing oxide crystal, Li 6.0 La 3 Zr 1.0 Nb 1.0 O 12, was grown using the CZ method.
  • the amount of Li contained in the raw material was 110% of Li contained in the obtained lithium-containing oxide crystal.
  • N 2 at 1 atm at room temperature was flowed at a flow rate of 4 liters per minute, and the dew point was set to ⁇ 62 ° C.
  • Ir material was used for the crucible.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 8 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 12.
  • the left side in FIG. 8 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the right side.
  • Example 12 As shown in FIG. 8, in Example 12, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 11 mm, and no crack was generated in the region. (Example 13)
  • Example 13 a lithium-containing oxide crystal, Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12, was grown using the CZ method.
  • N 2 at 1 atm at room temperature was flowed at a flow rate of 4 liters per minute, and the dew point was set to ⁇ 69 ° C.
  • Ir material was used for the crucible.
  • the obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
  • FIG. 9 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 13.
  • the left side in FIG. 9 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the right side.
  • Example 13 As shown in FIG. 9, in Example 13, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 12 mm, and no crack was generated in the region.

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Abstract

[Problem] To provide: a lithium-containing oxide crystal which is free from cracks, while having a large area; a battery which uses this lithium-containing oxide crystal; and a method for producing this lithium-containing oxide crystal. [Solution] The present invention comprises a molten part formation step wherein at least some of the starting material of the lithium-containing oxide crystal, said starting material containing oxygen, is melted so as to form a molten part, and a growth step wherein a lithium-containing oxide crystal is grown form the molten part; the dew point of the atmosphere of the growth step is within the range of from -70°C to -35°C; and the lithium-containing oxide crystal is free from cracks, while having a cross-sectional area of 0.38 cm2 or more.

Description

リチウム含有酸化物結晶、電池およびリチウム含有酸化物結晶の製造方法Lithium-containing oxide crystals, batteries and methods for producing lithium-containing oxide crystals
　本発明は、リチウム含有酸化物結晶、電池およびリチウム含有酸化物結晶の製造方法に関する。 The present invention relates to a lithium-containing oxide crystal, a battery, and a method for producing a lithium-containing oxide crystal.
　従来から、スマートフォン向けのバッテリーや電気自動車向けのバッテリー等にリチウムイオン電池が採用されている。従来のリチウムイオン電池では、Ｌｉ（リチウム）イオンが移動可能な電解質として電解液を用いていた。しかし、電解液を用いたリチウムイオン電池では、さらなる高容量化、高電圧化、高エネルギー密度化、及び急速充電性能を図ることが困難になってきている。そこで、これらの各種要求を満たすリチウムイオン電池として、電解液の代わりに固体電解質を用いる全固体電池の開発が進められている。全固体のリチウムイオン電池に用いられる固体電解質としては、硫化物系及び酸化物系のリチウムイオン結晶が挙げられる。 Conventionally, lithium-ion batteries have been used for batteries for smartphones and batteries for electric vehicles. In the conventional lithium ion battery, an electrolytic solution is used as an electrolyte in which Li (lithium) ions can move. However, in a lithium ion battery using an electrolytic solution, it has become difficult to further increase the capacity, increase the voltage, increase the energy density, and achieve quick charging performance. Therefore, as a lithium ion battery that meets these various requirements, an all-solid-state battery that uses a solid electrolyte instead of an electrolytic solution is being developed. Examples of the solid electrolyte used in the all-solid-state lithium-ion battery include sulfide-based and oxide-based lithium-ion crystals.
　硫化物系固体電解質は、Ｌｉイオン伝導度が高くエネルギー密度を重視した電池に適している。しかし固体電解質の結晶構造が高温により壊れた場合、有害物質（硫化水素（Ｈ２Ｓ））が放出されるという課題がある。そこで有害な物質が放出されず、より安全性と安定性が求められる用途向けに、酸化物系固体電解質の開発が進められている。 The sulfide-based solid electrolyte is suitable for a battery having high Li ion conductivity and emphasizing energy density. However, if the crystal structure of the solid electrolyte is broken by the high temperature, there is a problem that harmful substances (hydrogen sulfide (H 2 S)) is released. Therefore, the development of oxide-based solid electrolytes is underway for applications that do not release harmful substances and require greater safety and stability.
　一方で酸化物系固体電解質は、硫化物系固体電解質と比べてＬｉイオン伝導度が低いという課題がある。バルク型全固体電池へ応用する為には、室温に於ける導電率で１０－３（Ｓ／ｃｍ）以上を示す酸化物系固体電解質が望ましい。１０－３（Ｓ／ｃｍ）程度の導電率を示す酸化物系固体電解質として、例えばペロブスカイト型のＬａ０．５１Ｌｉ０．３４ＴｉＯ２．９４等のリチウム含有酸化物結晶が知られている（例えば、非特許文献１参照）。 On the other hand, the oxide-based solid electrolyte has a problem that the Li ion conductivity is lower than that of the sulfide-based solid electrolyte. In order to apply it to a bulk type all-solid-state battery, an oxide-based solid electrolyte having a conductivity of 10 -3 (S / cm) or more at room temperature is desirable. As an oxide-based solid electrolyte exhibiting a conductivity of about 10 -3 (S / cm), for example, lithium-containing oxide crystals such as perovskite type La 0.51 Li 0.34 TiO 2.94 are known ( For example, see Non-Patent Document 1).
　しかしリチウム含有酸化物結晶では、ＦＺ（Ｆｌｏａｔｉｎｇ　Ｚｏｎｅ）法、ＣＺ（Ｃｚｏｃｈｒａｌｓｋｉ）法、及びＥＦＧ（Ｅｄｇｅ－ｄｅｆｉｎｅｄ　Ｆｉｌｍ－ｆｅｄ　Ｇｒｏｗｔｈ）法等を用いて成長させた結晶に、クラックが発生するという問題があった。詳述すると、リチウム含有酸化物結晶原料の少なくとも一部を溶融して溶融部を形成し、溶融部からリチウム含有酸化物結晶を成長形成させた際に、結晶成長方向において溶融部の粘性の変化が発生すると共に、成長途中で急激に溶融部のメルトが切れて（ＦＺ法では垂れて）、結晶にクラックが生じてしまう。 However, in the lithium-containing oxide crystal, there is a problem that cracks occur in the crystal grown by using the FZ (Floating Zone) method, the CZ (Czochralski) method, the EFG (Edge-defined Film-fed Growth) method, or the like. there were. More specifically, when at least a part of the lithium-containing oxide crystal raw material is melted to form a molten portion and the lithium-containing oxide crystal is grown and formed from the molten portion, the viscosity of the molten portion changes in the crystal growth direction. At the same time, the melt of the molten part is suddenly cut off during the growth (dripping in the FZ method), and cracks occur in the crystal.
　リチウム含有酸化物結晶では、成長形成させる結晶の外形寸法を大きくする程クラックが生じやすく、歩留まり低下を招いていた。これにより、クラックが無く結晶品質の良好な大型のリチウム含有酸化物結晶を、歩留まり良く製造することは困難であった。 In the lithium-containing oxide crystal, the larger the external dimension of the crystal to be grown and formed, the more easily cracks are likely to occur, resulting in a decrease in yield. As a result, it has been difficult to produce a large-sized lithium-containing oxide crystal having no cracks and having good crystal quality with good yield.
　本発明は上記課題に鑑みてなされたものであり、クラックが無く大面積を有するリチウム含有酸化物結晶の提供を目的とするとともに、そのリチウム含有酸化物結晶の製造方法の提供も目的とする。さらに、そのリチウム含有酸化物結晶の少なくとも一部を備える電池の提供も目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a lithium-containing oxide crystal having a large area without cracks, and also to provide a method for producing the lithium-containing oxide crystal. Another object of the present invention is to provide a battery including at least a part of the lithium-containing oxide crystal.
　上記課題を解決するために、本発明のリチウム含有酸化物結晶は、クラックが無く、０．３８ｃｍ２以上の断面積を有し、酸素を含むことを特徴とする。 In order to solve the above problems, the lithium-containing oxide crystal of the present invention is characterized by having no cracks, having a cross section of 0.38 cm 2 or more, and containing oxygen.
　このような本発明のリチウム含有酸化物結晶では、クラックが無い大面積を有することで、全固体電池の高容量化と高導電率化を図ることが可能となる。 The lithium-containing oxide crystal of the present invention has a large area without cracks, so that the capacity and conductivity of the all-solid-state battery can be increased.
　また本発明の一態様では、前記断面積が１．７６ｃｍ２以上１００ｃｍ２以下である。 In the aspect of the present invention, the cross-sectional area is 1.76 cm 2 or more 100 cm 2 or less.
　また本発明の一態様では、長手方向の寸法を有し、前記長手方向の寸法が１０ｍｍ以上である。 Further, in one aspect of the present invention, it has a dimension in the longitudinal direction, and the dimension in the longitudinal direction is 10 mm or more.
　また上記課題を解決するために、本発明の電池は、上記何れか一つに記載のリチウム含有酸化物結晶の少なくとも一部を用いることを特徴とする。 Further, in order to solve the above-mentioned problems, the battery of the present invention is characterized in that at least a part of the lithium-containing oxide crystals described in any one of the above is used.
　また上記課題を解決するために、本発明のリチウム含有酸化物結晶の製造方法は、酸素を含むリチウム含有酸化物結晶原料の少なくとも一部を溶融して溶融部を形成する溶融部形成工程と、前記溶融部からリチウム含有酸化物結晶を成長形成する成長工程を有し、前記成長工程における雰囲気の露点は－７０℃以上－３５℃以下の範囲であり、前記リチウム含有酸化物結晶は０．３８ｃｍ２以上の断面積を有することを特徴とする。 Further, in order to solve the above problems, the method for producing a lithium-containing oxide crystal of the present invention includes a melted portion forming step of melting at least a part of an oxygen-containing lithium-containing oxide crystal raw material to form a melted portion. It has a growth step of growing and forming lithium-containing oxide crystals from the molten portion, and the dew point of the atmosphere in the growth step is in the range of −70 ° C. or higher and −35 ° C. or lower, and the lithium-containing oxide crystal is 0.38 cm. It is characterized by having a cross-sectional area of 2 or more.
　また本発明の一態様では、前記露点を－７０℃以上－４０℃以下の範囲内に設定し、前記溶融部から１．７６ｃｍ２以上１００ｃｍ２以下の面積を有する前記リチウム含有酸化物結晶を成長形成する。 In the aspect of the present invention, by setting the dew point in the range of -70 ° C. or higher -40 ℃ less, the growth of the lithium-containing oxide crystal having an area of from the molten portion 1.76 cm 2 or more 100 cm 2 or less Form.
　また本発明の一態様では、前記露点を－６５℃以上－４５℃以下の範囲内に設定し、前記溶融部から１０ｍｍ以上の長手方向の寸法で前記リチウム含有酸化物結晶を成長形成する。 Further, in one aspect of the present invention, the dew point is set within the range of −65 ° C. or higher and −45 ° C. or lower, and the lithium-containing oxide crystal is grown and formed at a dimension in the longitudinal direction of 10 mm or more from the molten portion.
　また本発明の一態様では、前記成長工程は、ＣＺ法又はＥＦＧ法を用いる。 Further, in one aspect of the present invention, the CZ method or the EFG method is used for the growth step.
　本発明によれば、クラックが無く大面積を有するリチウム含有酸化物結晶およびその製造方法を提供することができる。また、そのリチウム含有酸化物結晶の少なくとも一部を備える電池を提供することができる。 According to the present invention, it is possible to provide a lithium-containing oxide crystal having a large area without cracks and a method for producing the same. Further, it is possible to provide a battery including at least a part of the lithium-containing oxide crystal.
リチウム含有酸化物結晶に生じたクラックを示す断面観察写真である。It is a cross-sectional observation photograph which shows the crack which occurred in the lithium-containing oxide crystal. ＦＺ法を用いて成長したリチウム含有酸化物結晶の実施例１，２および比較例についての評価を示す表である。It is a table which shows the evaluation about Examples 1 and 2 and the comparative example of the lithium-containing oxide crystal grown by the FZ method. （ａ）～（ｃ）は、それぞれ実施例１，２および比較例１のリチウム含有酸化物結晶の外観を示す写真である。(A) to (c) are photographs showing the appearance of lithium-containing oxide crystals of Examples 1 and 2, respectively, and Comparative Example 1. 露点条件を変えてＦＺ法を用いて成長した実施例３～６および比較例２のリチウム含有酸化物結晶の外観写真を示す表である。It is a table which shows the appearance photograph of the lithium-containing oxide crystal of Examples 3-6 and Comparative Example 2 which grew by using the FZ method under the dew point condition. ＣＺ法を用いて成長したリチウム含有酸化物結晶の実施例７～１０についての評価を示す表である。It is a table which shows the evaluation about Examples 7-10 of the lithium-containing oxide crystal grown by the CZ method. （ａ）～（ｄ）は、それぞれ実施例７～１０のリチウム含有酸化物結晶の外観を示す写真である。(A) to (d) are photographs showing the appearance of the lithium-containing oxide crystals of Examples 7 to 10, respectively. 実施例１１のリチウム含有酸化物結晶の外観を示す写真である。It is a photograph which shows the appearance of the lithium-containing oxide crystal of Example 11. 実施例１２のリチウム含有酸化物結晶の外観を示す写真である。It is a photograph which shows the appearance of the lithium-containing oxide crystal of Example 12. 実施例１３のリチウム含有酸化物結晶の外観を示す写真である。It is a photograph which shows the appearance of the lithium-containing oxide crystal of Example 13.
　本実施の形態の第一の特徴は、リチウム含有酸化物結晶はクラックが無く、０．３８ｃｍ２以上の断面積を有し、酸素を含むとしたことである。 The first feature of the present embodiment is that the lithium-containing oxide crystal has no cracks, has a cross section of 0.38 cm 2 or more, and contains oxygen.
　この構成に依れば、クラックが無い大面積を有することで、全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to increase the capacity and conductivity of the all-solid-state battery by having a large area without cracks.
　第二の特徴は、断面積が１．７６ｃｍ２以上１００ｃｍ２以下としたことである。 The second feature is that the cross-sectional area was 1.76 cm 2 or more 100 cm 2 or less.
　この構成に依れば、より大型のリチウム含有酸化物結晶を形成し、さらなる全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to form a larger lithium-containing oxide crystal and further increase the capacity and conductivity of the all-solid-state battery.
　第三の特徴は、長手方向の寸法を有し、長手方向の寸法が１０ｍｍ以上としたことである。 The third feature is that it has a longitudinal dimension, and the longitudinal dimension is 10 mm or more.
　この構成に依れば、リチウム含有酸化物結晶の体積を増加させて、生産性の向上やさらなる全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to increase the volume of the lithium-containing oxide crystal to improve productivity, further increase the capacity of the all-solid-state battery, and increase the conductivity.
　第四の特徴は、上記何れか一つに記載のリチウム含有酸化物結晶の少なくとも一部を用いる電池としたことである。 The fourth feature is that the battery uses at least a part of the lithium-containing oxide crystals described in any one of the above.
　この構成に依れば、大型のリチウム含有酸化物結晶を用いることで、例えば０．５（ｍＳ／ｃｍ）以上の高導電率で高容量な全固体電池を実現できる。 According to this configuration, by using a large lithium-containing oxide crystal, it is possible to realize an all-solid-state battery having a high conductivity of 0.5 (mS / cm) or more and a high capacity.
　第五の特徴は、リチウム含有酸化物結晶の製造方法は、酸素を含むリチウム含有酸化物結晶原料の少なくとも一部を溶融して溶融部を形成する溶融部形成工程と、溶融部からリチウム含有酸化物結晶を成長形成する成長工程を有し、成長工程における雰囲気の露点は－７０℃以上－３５℃以下の範囲であり、リチウム含有酸化物結晶は０．３８ｃｍ２以上の断面積を有するとしたことである。 The fifth feature is that the method for producing a lithium-containing oxide crystal is a melt portion forming step of melting at least a part of an oxygen-containing lithium-containing oxide crystal raw material to form a melt portion, and a lithium-containing oxidation from the melt portion. It has a growth step of growing and forming a physical crystal, the dew point of the atmosphere in the growth step is in the range of -70 ° C or higher and -35 ° C or lower, and the lithium-containing oxide crystal has a cross-sectional area of 0.38 cm 2 or more. That is.
　この構成に依れば、酸素を含むリチウム含有酸化物結晶を、クラックが無く、少なくとも０．３８ｃｍ２以上の面積を有する大型に実現可能となる。さらに、得られたリチウム含有酸化物結晶を電池に使用することにより、高容量の電池を容易に形成することが可能となる。 According to this configuration, it is possible to realize a large-sized lithium-containing oxide crystal containing oxygen without cracks and having an area of at least 0.38 cm 2 or more. Further, by using the obtained lithium-containing oxide crystal in the battery, it becomes possible to easily form a high-capacity battery.
　第六の特徴は、露点を－７０℃以上－４０℃以下の範囲内に設定し、溶融部から１．７６ｃｍ２以上１００ｃｍ２以下の面積を有するリチウム含有酸化物結晶を成長形成するとしたことである。 Sixth aspect, by setting the dew point in the range of -70 ° C. or higher -40 ℃ below were to grow forming a lithium-containing oxide crystal having an area of 1.76 cm 2 or more 100 cm 2 or less from the molten portion is there.
　この構成に依れば、より大型のリチウム含有酸化物結晶を形成し、さらなる全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to form a larger lithium-containing oxide crystal and further increase the capacity and conductivity of the all-solid-state battery.
　第七の特徴は、露点を－６５℃以上－４５℃以下の範囲内に設定し、溶融部から１０ｍｍ以上の長手方向の寸法でリチウム含有酸化物結晶を成長形成するとしたことである。 The seventh feature is that the dew point is set within the range of -65 ° C or higher and -45 ° C or lower, and lithium-containing oxide crystals are grown and formed in the longitudinal dimension of 10 mm or more from the molten portion.
　この構成に依れば、リチウム含有酸化物結晶の体積を増加させて、生産性の向上やさらなる全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to increase the volume of the lithium-containing oxide crystal to improve productivity, further increase the capacity of the all-solid-state battery, and increase the conductivity.
　第八の特徴は、成長工程は、ＣＺ法又はＥＦＧ法を用いるとしたことである。 The eighth feature is that the CZ method or the EFG method is used for the growth process.
　この構成に依れば、リチウム含有酸化物結晶の大口径化を図ることができ、さらなる全固体電池の高容量化と高導電率化を図ることが可能となる。 According to this configuration, it is possible to increase the diameter of the lithium-containing oxide crystal, and further increase the capacity and conductivity of the all-solid-state battery.
　以下、本発明の実施の形態について、図面を参照して詳細に説明する。各図面に示される同一または同等の構成要素、部材、処理には、同一の符号を付すものとし、適宜重複した説明は省略する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate.
　本実施形態のリチウム含有酸化物結晶は、酸素を含みクラックが無く０．３８ｃｍ２以上の断面積を有し、一般式Ｌｉ７－ｘ－ｙＬａ３Ｚｒ２－ｘ－ｙＮｂｘＴａｙＯ１２（０．２≦ｘ＋ｙ≦１．０、０≦ｘ≦１．０、０≦ｙ≦１．０）で表され、立方晶系のガーネット型構造を有している。より好ましくは、断面積が１．７６ｃｍ２以上１００ｃｍ２以下の範囲である。またリチウム含有酸化物結晶は、長手方向の寸法を有し、長手方向の寸法が１０ｍｍ以上であることが好ましい。リチウム含有酸化物結晶にクラックが無く大きな面積と体積を有することで、生産性の向上や全固体電池の高容量化と高導電率化を図ることが可能となる。ここで高導電率とは、電池内部の固体電解質の伝導率が、例えば０．５（ｍＳ／ｃｍ）以上である。 Lithium-containing oxide crystal of the present embodiment, the crack includes oxygen has no 0.38 cm 2 or more cross-sectional area, the general formula Li 7-x-y La 3 Zr 2-x-y Nb x Ta y O It is represented by 12 (0.2 ≦ x + y ≦ 1.0, 0 ≦ x ≦ 1.0, 0 ≦ y ≦ 1.0) and has a cubic garnet-type structure. More preferably, in the range sectional area of 1.76 cm 2 or more 100 cm 2 or less. Further, the lithium-containing oxide crystal has a dimension in the longitudinal direction, and the dimension in the longitudinal direction is preferably 10 mm or more. Since the lithium-containing oxide crystal has no cracks and has a large area and volume, it is possible to improve productivity, increase the capacity of the all-solid-state battery, and increase the conductivity. Here, the high conductivity means that the conductivity of the solid electrolyte inside the battery is, for example, 0.5 (mS / cm) or more.
　本実施形態においてクラックとは、リチウム含有酸化物結晶に発生する割れのうち、光学顕微鏡で確認可能であり１ｍｍを超える割れを指す。また、クラックが無いリチウム含有酸化物結晶としては、結晶成長直後のａｓ－ｇｒｏｗｎで結晶全体にクラックが存在しないことが好ましいが、部分的にクラックが無い領域が形成されている場合も含む。さらに、結晶成長後に表面を研磨または切断することでクラックを除去した場合も含む。また、クラックが無い断面積とは、リチウムイオン酸化物結晶のうち、クラックの含まれていない領域が最大となる方向の面積を意味するが、結晶成長方向に垂直な面における断面積であることが面内における結晶品質の均一化を図ることができるため好ましい。 In the present embodiment, the crack refers to a crack that can be confirmed with an optical microscope and exceeds 1 mm among the cracks generated in the lithium-containing oxide crystal. Further, as the lithium-containing oxide crystal having no cracks, it is preferable that there are no cracks in the entire crystal in as-grown immediately after crystal growth, but it also includes a case where a region without cracks is partially formed. Further, the case where cracks are removed by polishing or cutting the surface after crystal growth is also included. The crack-free cross-sectional area means the area of the lithium ion oxide crystal in the direction in which the crack-free region is maximized, but is the cross-sectional area in the plane perpendicular to the crystal growth direction. Is preferable because the crystal quality in the plane can be made uniform.
　図１は、リチウム含有酸化物結晶と結晶に生じたクラックを示す断面観察写真である。ここで、図１の下方に示された目盛りは１ｍｍであり、図中に示したリチウム含有酸化物結晶は直径が７ｍｍ程度の円盤状である。図１に示したように、リチウム含有酸化物結晶を成長方向に垂直な面で切断すると、結晶の外周から内部に向かって複数のクラックが伸びていることがわかる。このように、リチウム含有酸化物結晶にクラックが含まれていると、全固体電池に用いた場合に信頼性の低下や容量の低下、寿命の低下などの不具合が生じるおそれがあるため好ましくない。それに対して、直径が７ｍｍ程度の範囲内にクラックが無いリチウム含有酸化物結晶では、０．３８ｃｍ２以上の断面積を有しており全固体電池の高容量化と高導電率化を図ることができる。 FIG. 1 is a cross-sectional observation photograph showing a lithium-containing oxide crystal and cracks formed in the crystal. Here, the scale shown in the lower part of FIG. 1 is 1 mm, and the lithium-containing oxide crystal shown in the figure has a disk shape having a diameter of about 7 mm. As shown in FIG. 1, when the lithium-containing oxide crystal is cut in a plane perpendicular to the growth direction, it can be seen that a plurality of cracks extend from the outer periphery of the crystal toward the inside. As described above, if the lithium-containing oxide crystal contains cracks, problems such as a decrease in reliability, a decrease in capacity, and a decrease in life may occur when used in an all-solid-state battery, which is not preferable. On the other hand, a lithium-containing oxide crystal having no cracks within a diameter of about 7 mm has a cross section of 0.38 cm 2 or more, and the capacity and conductivity of the all-solid-state battery should be increased. Can be done.
　はじめに、本実施形態のリチウム含有酸化物結晶の製造方法は、原料準備工程としてリチウム含有酸化物結晶の各種原料を準備し、粉砕したうえ所定比率で混合して原料を粉末状に加工する。粉砕および混合の方法は限定されず、公知の方法を用いることができる。その後に、成形工程で粉末状の原料を加圧成形して焼成し、原料焼結体を得る。加圧成形および焼成の方法が限定されず、公知の方法を用いることができる。 First, in the method for producing lithium-containing oxide crystals of the present embodiment, various raw materials of lithium-containing oxide crystals are prepared as a raw material preparation step, crushed and mixed at a predetermined ratio to process the raw materials into powder. The method of pulverization and mixing is not limited, and known methods can be used. After that, in the molding step, the powdered raw material is pressure-molded and fired to obtain a raw material sintered body. The methods of pressure molding and firing are not limited, and known methods can be used.
　リチウム含有酸化物結晶の原料としては、リチウム化合物、ランタン化合物、ジルコニウム化合物、タンタル化合物、ニオブ化合物を用いることができる。リチウム化合物としては、例えばＬｉ２ＯやＬｉ２ＣＯ３などが挙げられる。ランタン化合物としては、例えばＬａ２Ｏ３やＬａ（ＯＨ）３などが挙げられる。ジルコニウム化合物としては、例えばＺｒＯ２、ＺｒＣｌ４、Ｌａ２Ｚｒ２Ｏ７、Ｌｉ２ＺｒＯ３などが挙げられる。タンタル化合物としては、例えばＴａ２Ｏ５やＴａＣｌ５などが挙げられる。ニオブ化合物としては、例えばＮｂ２Ｏ５、ＬｉＮｂＯ３、ＬａＮｂＯ４などが挙げられる。 As a raw material for the lithium-containing oxide crystal, a lithium compound, a lanthanum compound, a zirconium compound, a tantalum compound, and a niobium compound can be used. Examples of the lithium compound include Li 2 O and Li 2 CO 3 . Examples of the lanthanum compound include La 2 O 3 and La (OH) 3 . Examples of the zirconium compound include ZrO 2 , ZrC l4 , La 2 Zr 2 O 7 , Li 2 ZrO 3, and the like. Examples of the tantalum compound include Ta 2 O 5 and Ta C l 5 . Examples of the niobium compound include Nb 2 O 5 , LiNbO 3 , and LaNbO 4 .
　次に、溶融部形成工程で原料焼結体の少なくとも一部を溶融して溶融部を形成し、成長工程で溶融部を冷却してリチウム含有酸化物結晶を成長させる。溶融部形成工程および成長工程の方法は限定されず、公知の各種溶融法を用いて結晶成長することができ、例えばＦＺ（Ｆｌｏａｔｉｎｇ　Ｚｏｎｅ）法、ブリッジマン法、キロポーラス法、ＴＳＳＧ（Ｔｏｐ　Ｓｅｅｄｅｄ　Ｓｏｌｕｔｉｏｎ　Ｇｒｏｗｔｈ）法、ＬＰＥ（Ｌｉｑｕｉｄ　Ｐｈａｓｅ　Ｅｐｉｔａｘｙ）法、ＣＺ（Ｃｚｏｃｈｒａｌｓｋｉ）法、ＥＦＧ（Ｅｄｇｅ－ｄｅｆｉｎｅｄ　Ｆｉｌｍ－ｆｅｄ　Ｇｒｏｗｔｈ）法が挙げられる。リチウム含有酸化物結晶の大口径化を図るためには、ＣＺ法又はＥＦＧ法を用いることが好ましい。坩堝を用いる成長方法の場合には、原料メルトと反応しないＩｒを坩堝の材料として用いることが好ましい。 Next, at least a part of the raw material sintered body is melted to form a melted portion in the melted portion forming step, and the melted portion is cooled in the growth step to grow a lithium-containing oxide crystal. The method of the molten portion forming step and the growing step is not limited, and the crystal can be grown by using various known melting methods. For example, the FZ (Floating Zone) method, the Bridgeman method, the kiloporous method, and the TSSG (Top Edged Solution). Examples include the Growth) method, the LPE (Liquid Phase Epitaxy) method, the CZ (Czochralski) method, and the EFG (Edge-defined Film-fed Growth) method. In order to increase the diameter of the lithium-containing oxide crystal, it is preferable to use the CZ method or the EFG method. In the case of a growth method using a crucible, it is preferable to use Ir, which does not react with the raw material melt, as a material for the crucible.
　成長工程において用いる雰囲気はＮ２またはＡｒ、ドライエアーが好適であり、雰囲気の露点を－７０℃以上－３５℃以下の範囲とする。本実施形態において雰囲気の露点とは、雰囲気中に含まれる水蒸気量が同気圧における飽和水蒸気量となる温度のことを意味する。なお、本実施形態及び後述する実施例と比較例において、雰囲気の露点測定には静電容量式の露点計（株式会社テクネ計測製　オンライン露点計ＴＫ－１００）を用いた。 The atmosphere used in the growth step is preferably N 2 or Ar, and dry air, and the dew point of the atmosphere is in the range of −70 ° C. or higher and −35 ° C. or lower. In the present embodiment, the dew point of the atmosphere means a temperature at which the amount of water vapor contained in the atmosphere becomes the saturated water vapor amount at the same atmospheric pressure. In this embodiment and the examples and comparative examples described later, a capacitance type dew point meter (online dew point meter TK-100 manufactured by Tekne Corporation) was used for measuring the dew point of the atmosphere.
　本出願人は、成長工程における雰囲気の露点によって、結晶に含まれるＬｉ含有量が変化し、クラックが発生することを見出した。リチウム含有酸化物結晶では、Ｌｉ含有量の変化に伴い外観に白濁やクラックが発生し、結晶内における特性のばらつきが生じてしまう。成長工程における雰囲気の露点を－７０℃以上－３５℃以下の範囲とすることで、白濁やクラックを抑制して特性のばらつきを抑制して０．３８ｃｍ２以上の断面積を有する均一なリチウム含有酸化物結晶を得ることができる。 The applicant has found that the Li content contained in the crystal changes depending on the dew point of the atmosphere in the growth process, and cracks occur. In the lithium-containing oxide crystal, white turbidity and cracks occur in the appearance as the Li content changes, and the characteristics in the crystal vary. By setting the dew point of the atmosphere in the growth process to the range of -70 ° C or higher and -35 ° C or lower, white turbidity and cracks are suppressed and variation in characteristics is suppressed, and a uniform lithium content having a cross section of 0.38 cm 2 or more is contained. Oxide crystals can be obtained.
　また、成長工程における雰囲気の露点を－７０℃以上－４０℃以下の範囲内に設定することで、溶融部から１．７６ｃｍ２以上１００ｃｍ２以下の面積を有するリチウム含有酸化物結晶を成長形成することができる。さらに、成長工程における雰囲気の露点を－６５℃以上－４５℃以下の範囲内に設定することで、溶融部から１０ｍｍ以上の長手方向の寸法（即ち、リチウム含有酸化物結晶の成長方向における長さ）でリチウム含有酸化物結晶を成長形成することができる。 Further, by setting the dew point of the atmosphere in the growth step in the range of -70 ° C. or higher -40 ℃ less, grown form a lithium-containing oxide crystal having an area of 1.76 cm 2 or more 100 cm 2 or less from the molten portion be able to. Further, by setting the dew point of the atmosphere in the growth step within the range of -65 ° C. or higher and -45 ° C. or lower, the dimension in the longitudinal direction of 10 mm or more from the molten portion (that is, the length in the growth direction of the lithium-containing oxide crystal). ) Can grow and form lithium-containing oxide crystals.
　以下に本発明に係る実施例を説明するが、本発明は以下の実施例のみに限定されない。
（実施例１，２および比較例１） Examples of the present invention will be described below, but the present invention is not limited to the following examples.
(Examples 1 and 2 and Comparative Example 1)
　まず、実施例１，２および比較例１として、ＦＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．５Ｏ１２を成長させた。原料に含まれるＬｉの量は、得られるリチウム含有酸化物結晶に含まれるＬｉの１０８％とした。成長工程中の雰囲気は、室温で１気圧の空気（ドライエアー）を毎分７リットルの流量で流し、実施例１，２および比較例１は、それぞれ露点が－３５℃、－５５℃、－２０℃の条件に設定した。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 First, as Examples 1 and 2 and Comparative Example 1, Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 which is a lithium-containing oxide crystal was grown by using the FZ method. The amount of Li contained in the raw material was 108% of Li contained in the obtained lithium-containing oxide crystal. In the atmosphere during the growth process, air (dry air) at room temperature of 1 atm was flowed at a flow rate of 7 liters per minute, and the dew points of Examples 1 and 2 and Comparative Example 1 were −35 ° C., −55 ° C., and −, respectively. The condition was set to 20 ° C. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　図２は、ＦＺ法を用いて成長したリチウム含有酸化物結晶の実施例１，２および比較例１についての評価を示す表である。図２中の面積の欄は、クラックが生じていない部分における断面積を示し、長さの欄は断面積が０．３８ｃｍ２以上でクラックが生じていない部分の成長方向における長さを示している。図３（ａ）～（ｃ）は、それぞれ実施例１，２および比較例１のリチウム含有酸化物結晶の外観を示す写真である。図３（ａ）～（ｃ）における左側が結晶成長の開始側であり、右側に向かって原料の溶融および成長をさせたａｓ－ｇｒｏｗｎの状態を示している。 FIG. 2 is a table showing evaluations of Examples 1 and 2 and Comparative Example 1 of lithium-containing oxide crystals grown by the FZ method. The area column in FIG. 2 shows the cross-sectional area in the non-cracked portion, and the length column shows the length in the growth direction of the non-cracked portion having a cross-sectional area of 0.38 cm 2 or more. There is. 3 (a) to 3 (c) are photographs showing the appearance of the lithium-containing oxide crystals of Examples 1 and 2, respectively. The left side in FIGS. 3 (a) to 3 (c) is the start side of crystal growth, and the state of as-grown in which the raw material is melted and grown is shown toward the right side.
　図２および図３に示したように、実施例１では直径７ｍｍで断面積が０．３８ｃｍ２の領域が１０ｍｍ存在しており、当該領域内においてクラックは生じていなかった。また実施例２では直径７ｍｍで断面積が０．３８ｃｍ２の領域が４０ｍｍ存在しており、当該領域内においてクラックは生じていなかった。一方、比較例１ではリチウム含有酸化物結晶の全面にクラックがあり、クラックが含まれない領域が存在しなかった。したがって、露点が－３５℃より大きい場合には、断面積が０．３８ｃｍ２以上のクラックが無いリチウム含有酸化物結晶を得られないことがわかる。
（実施例３～６および比較例２） As shown in FIGS. 2 and 3, in Example 1, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 10 mm, and no crack was generated in the region. Further, in Example 2, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 existed in an area of 40 mm, and no crack was generated in the region. On the other hand, in Comparative Example 1, there were cracks on the entire surface of the lithium-containing oxide crystal, and there was no region not containing the cracks. Therefore, when the dew point is larger than −35 ° C., it can be seen that a lithium-containing oxide crystal having a cross section of 0.38 cm 2 or more and without cracks cannot be obtained.
(Examples 3 to 6 and Comparative Example 2)
　次に、実施例３～６および比較例２として、ＦＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．５Ｏ１２を成長させた。原料に含まれるＬｉの量は、得られるリチウム含有酸化物結晶に含まれるＬｉの１０８％とした。成長工程中の雰囲気は、室温で１気圧の空気（ドライエアー）を毎分７リットルの流量で流し、実施例３～６および比較例２は、それぞれ露点が－４０℃、－４３℃、－４８℃、－６２℃、－６８℃の条件に設定した。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 Next, as Examples 3 to 6 and Comparative Example 2, Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 , which is a lithium-containing oxide crystal, was grown using the FZ method. The amount of Li contained in the raw material was 108% of Li contained in the obtained lithium-containing oxide crystal. The atmosphere during the growth process was such that 1 atm of air (dry air) was flowed at a flow rate of 7 liters per minute at room temperature, and the dew points of Examples 3 to 6 and Comparative Example 2 were −40 ° C., −43 ° C., and −, respectively. The conditions were set at 48 ° C., −62 ° C., and −68 ° C. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　図４は、露点条件を変えてＦＺ法を用いて成長した実施例３～６および比較例２のリチウム含有酸化物結晶の外観写真を示す表である。図４に於いて、露点－４０℃が実施例３、露点－４３℃が実施例４、露点－４８℃が実施例５、露点－６２℃が実施例６、露点－６８℃が比較例２である、実施例３～６の何れにおいても、断面積が０．３８ｃｍ２の領域が存在しており、当該領域内においてクラックは生じていなかった。また、実施例３～６および比較例２の何れにおいても、導電率は０．６５（ｍＳ／ｃｍ）以上であり、特に実施例５では０．８５（ｍＳ／ｃｍ）であった。一方、比較例２ではリチウム含有酸化物結晶の結晶成長方向に沿ってクラックが生じており、クラックが含まれない領域が存在しなかった。 FIG. 4 is a table showing external photographs of lithium-containing oxide crystals of Examples 3 to 6 and Comparative Example 2 grown by using the FZ method under different dew point conditions. In FIG. 4, a dew point of −40 ° C. is Example 3, a dew point of −43 ° C. is Example 4, a dew point of −48 ° C. is Example 5, a dew point of −62 ° C. is Example 6, and a dew point of −68 ° C. is Comparative Example 2. In each of Examples 3 to 6, a region having a cross section of 0.38 cm 2 existed, and no crack was generated in the region. Further, in both Examples 3 to 6 and Comparative Example 2, the conductivity was 0.65 (mS / cm) or more, and in particular, in Example 5, it was 0.85 (mS / cm). On the other hand, in Comparative Example 2, cracks were generated along the crystal growth direction of the lithium-containing oxide crystal, and there was no region containing no cracks.
　図４に示したように、実施例３ではＬｉ不足による白濁が部分的に生じており、断面積が０．３８ｃｍ２以上でクラックの無い領域は１０ｍｍ未満であった。また、実施例４でも断面積が０．３８ｃｍ２以上でクラックの無い領域は１０ｍｍ未満であった。したがって、露点を－６５℃以上－４５℃以下の範囲内に設定することで、断面積が０．３８ｃｍ２以上でクラックの無い領域を１０ｍｍ以上の寸法で形成できることがわかる。
（実施例７～１０） As shown in FIG. 4, in Example 3, white turbidity was partially generated due to lack of Li, and the cross section was 0.38 cm 2 or more and the crack-free region was less than 10 mm. Further, also in Example 4, the cross section was 0.38 cm 2 or more and the region without cracks was less than 10 mm. Therefore, it can be seen that by setting the dew point within the range of −65 ° C. or higher and −45 ° C. or lower, a region having a cross section of 0.38 cm 2 or more and no cracks can be formed with a size of 10 mm or more.
(Examples 7 to 10)
　次に、実施例７～１０として、ＣＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．５Ｏ１２とＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．２５Ｔａ０．２５Ｏ１２を成長させた。成長工程中の雰囲気は、室温で１気圧のＮ２を毎分２～４リットルの流量で流し、実施例７～１０は、それぞれ露点が－４０℃、－６５℃、－６６℃、－６９℃の条件に設定した。坩堝にはＩｒ材料を用いた。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 Next, as Examples 7 to 10, using the CZ method, Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 and Li 6.5 La 3 Zr 1.5 , which are lithium-containing oxide crystals, are used. Nb 0.25 Ta 0.25 O 12 was grown. In the atmosphere during the growth process, N 2 at 1 atm at room temperature was flowed at a flow rate of 2 to 4 liters per minute, and the dew points of Examples 7 to 10 were −40 ° C., −65 ° C., −66 ° C., and −69, respectively. The condition was set to ℃. Ir material was used for the crucible. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　図５は、ＣＺ法を用いて成長したリチウム含有酸化物結晶の実施例７～１０についての評価を示す表である。図５中の面積の欄は、クラックが生じていない部分における断面積を示し、長さの欄は断面積が０．３８ｃｍ２以上でクラックが生じていない部分の成長方向における長さを示している。また、実施例７，８，１０はＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．５Ｏ１２とあり、実施例９はＴａを含むＬｉ６．５Ｌａ３Ｚｒ１．５Ｎｂ０．２５Ｔａ０．２５Ｏ１２である。図６（ａ）～（ｄ）は、それぞれ実施例７～１０のリチウム含有酸化物結晶の外観を示す写真である。図６（ａ）～（ｄ）における左側が結晶成長の開始側であり、右側に向かって原料の溶融および成長をさせたａｓ－ｇｒｏｗｎの状態を示している。 FIG. 5 is a table showing the evaluation of Examples 7 to 10 of the lithium-containing oxide crystals grown by the CZ method. The area column in FIG. 5 shows the cross-sectional area in the non-cracked portion, and the length column shows the length in the growth direction of the non-cracked portion having a cross-sectional area of 0.38 cm 2 or more. There is. Further, Examples 7, 8 and 10 have Li 6.5 La 3 Zr 1.5 Nb 0.5 O 12 , and Example 9 has Li 6.5 La 3 Zr 1.5 Nb 0.25 containing Ta. It is Ta 0.25 O 12 . 6 (a) to 6 (d) are photographs showing the appearance of the lithium-containing oxide crystals of Examples 7 to 10, respectively. The left side in FIGS. 6 (a) to 6 (d) is the start side of crystal growth, and the state of as-grown in which the raw material is melted and grown is shown toward the right side.
　図５および図６に示したように、実施例７では成長初期段階において直径１８ｍｍで断面積が２．７６ｃｍ２のクラックが無い領域が形成されており、断面積が０．３８ｃｍ２以上でクラックが生じていない部分も１１ｍｍ存在していた。また実施例８では、直径１５ｍｍで断面積が１．７７ｃｍ２のクラックが無い領域が形成されており、断面積が０．３８ｃｍ２以上でクラックが生じていない部分も３８ｍｍ存在していた。また実施例９では、直径９．６ｍｍで断面積が０．７２ｃｍ２のクラックが無い領域が形成されており、断面積が０．３８ｃｍ２以上でクラックが生じていない部分も２７ｍｍ存在していた。また実施例１０では、部分的に割れが生じたものの、直径１６ｍｍで断面積が２．０ｃｍ２のクラックが無い領域が形成されており、断面積が０．３８ｃｍ２以上でクラックが生じていない部分も２４ｍｍ存在していた。 As shown in FIGS. 5 and 6, in Example 7, a crack-free region having a diameter of 18 mm and a cross section of 2.76 cm 2 was formed in the initial stage of growth, and cracks were formed when the cross section was 0.38 cm 2 or more. There was also a portion of 11 mm in which was not generated. Further, in Example 8, a crack-free region having a diameter of 15 mm and a cross section of 1.77 cm 2 was formed, and a portion having a cross section of 0.38 cm 2 or more and no cracks was also present at 38 mm. Further, in Example 9, a crack-free region having a diameter of 9.6 mm and a cross section of 0.72 cm 2 was formed, and there was a portion having a cross section of 0.38 cm 2 or more and no cracks of 27 mm. .. Further, in Example 10, although cracks were partially generated, a crack-free region having a diameter of 16 mm and a cross section of 2.0 cm 2 was formed, and cracks were not generated when the cross section was 0.38 cm 2 or more. The part was also present at 24 mm.
　したがって、露点を－７０℃以上－４０℃以下の範囲内に設定することで、断面積が１．７６ｃｍ２以上１００ｃｍ２以下の面積を有するクラックが無いリチウム含有酸化物結晶が得られることがわかる。
（実施例１１） Therefore, by setting the dew point in the range of -70 ° C. or higher -40 ℃ less, it can be seen that the lithium-containing oxide crack no cross-sectional area has an area of 1.76 cm 2 or more 100 cm 2 or less crystals are obtained ..
(Example 11)
　次に、実施例１１として、ＣＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．８Ｌａ３Ｚｒ１．８Ｎｂ０．２Ｏ１２を成長させた。成長工程中の雰囲気は、室温で１気圧のＮ２を毎分２～４リットルの流量で流し、露点が－６５℃の条件に設定した。坩堝にはＩｒ材料を用いた。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 Next, as Example 11, a lithium-containing oxide crystal, Li 6.8 La 3 Zr 1.8 Nb 0.2 O 12, was grown using the CZ method. The atmosphere during the growth process was set to a dew point of −65 ° C. by flowing N 2 at room temperature at a flow rate of 2 to 4 liters per minute. Ir material was used for the crucible. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　以下に、ＣＺ法を用いて成長したリチウム含有酸化物結晶の実施例１１についての評価を示す。また図７は実施例１１のリチウム含有酸化物結晶の外観を示す写真である。図７における右側が結晶成長の開始側であり、左側に向かって原料の溶融および成長をさせたａｓ－ｇｒｏｗｎの状態を示している。 The evaluation of Example 11 of the lithium-containing oxide crystal grown by the CZ method is shown below. Further, FIG. 7 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 11. The right side in FIG. 7 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the left side.
　図７に示したように、実施例１１ではクラックが無い領域が、直径９．５ｍｍ、断面積０．７０ｃｍ２で形成されており、断面積が０．３８ｃｍ２以上でクラックが生じていない部分も長手方向の寸法（成長方向における長さ）で３０ｍｍ存在していた。 As shown in FIG. 7, in Example 11, a crack-free region is formed with a diameter of 9.5 mm and a cross section of 0.70 cm 2 , and a portion having a cross section of 0.38 cm 2 or more and no cracks. Also existed in the longitudinal dimension (length in the growth direction) of 30 mm.
　したがって、露点を－６５℃に設定することで、断面積が０．３８ｃｍ２以上の面積で、且つ長手方向の寸法で１０ｍｍ以上に亘ってクラックが無いリチウム含有酸化物結晶が得られることがわかる。 Therefore, it can be seen that by setting the dew point to −65 ° C., a lithium-containing oxide crystal having a cross-sectional area of 0.38 cm 2 or more and a longitudinal dimension of 10 mm or more without cracks can be obtained. ..
　上述したように本実施形態では、クラックが無く大面積を有するリチウム含有酸化物結晶およびその製造方法を提供することができる。また、そのリチウム含有酸化物結晶の少なくとも一部を備える電池を提供することができる。
（実施例１２） As described above, in the present embodiment, it is possible to provide a lithium-containing oxide crystal having a large area without cracks and a method for producing the same. Further, it is possible to provide a battery including at least a part of the lithium-containing oxide crystal.
(Example 12)
  次に、実施例１２として、ＣＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．０Ｌａ３Ｚｒ１．０Ｎｂ１．０Ｏ１２を成長させた。原料に含まれるＬｉの量は、得られるリチウム含有酸化物結晶に含まれるＬｉの１１０％とした。成長工程中の雰囲気は、室温で１気圧のＮ２を毎分４リットルの流量で流し、露点を－６２℃の条件に設定した。坩堝にはＩｒ材料を用いた。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 Next, as Example 12, a lithium-containing oxide crystal, Li 6.0 La 3 Zr 1.0 Nb 1.0 O 12, was grown using the CZ method. The amount of Li contained in the raw material was 110% of Li contained in the obtained lithium-containing oxide crystal. As for the atmosphere during the growth process, N 2 at 1 atm at room temperature was flowed at a flow rate of 4 liters per minute, and the dew point was set to −62 ° C. Ir material was used for the crucible. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　図８は、実施例１２のリチウム含有酸化物結晶の外観を示す写真である。図８における左側が結晶成長の開始側であり、右側に向かって原料の溶融および成長をさせたａｓ－ｇｒｏｗｎの状態を示している。 FIG. 8 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 12. The left side in FIG. 8 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the right side.
　図８に示したように、実施例１２では直径７ｍｍで断面積が０．３８ｃｍ２の領域が１１ｍｍ存在しており、当該領域内においてクラックは生じていなかった。
（実施例１３） As shown in FIG. 8, in Example 12, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 11 mm, and no crack was generated in the region.
(Example 13)
　次に、実施例１３として、ＣＺ法を用いて、リチウム含有酸化物結晶であるＬｉ６．５Ｌａ３Ｚｒ１．５Ｔａ０．５Ｏ１２を成長させた。成長工程中の雰囲気は、室温で１気圧のＮ２を毎分４リットルの流量で流し、露点を－６９℃の条件に設定した。坩堝にはＩｒ材料を用いた。得られたリチウム含有酸化物結晶について、光学顕微鏡を用いて外観検査を行った。 Next, as Example 13, a lithium-containing oxide crystal, Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12, was grown using the CZ method. As for the atmosphere during the growth process, N 2 at 1 atm at room temperature was flowed at a flow rate of 4 liters per minute, and the dew point was set to −69 ° C. Ir material was used for the crucible. The obtained lithium-containing oxide crystals were visually inspected using an optical microscope.
　図９は、実施例１３のリチウム含有酸化物結晶の外観を示す写真である。図９における左側が結晶成長の開始側であり、右側に向かって原料の溶融および成長をさせたａｓ－ｇｒｏｗｎの状態を示している。 FIG. 9 is a photograph showing the appearance of the lithium-containing oxide crystal of Example 13. The left side in FIG. 9 is the start side of crystal growth, and the state of as-grown in which the raw materials are melted and grown is shown toward the right side.
　図９に示したように、実施例１３では直径７ｍｍで断面積が０．３８ｃｍ２の領域が１２ｍｍ存在しており、当該領域内においてクラックは生じていなかった。 As shown in FIG. 9, in Example 13, a region having a diameter of 7 mm and a cross section of 0.38 cm 2 was present at 12 mm, and no crack was generated in the region.
　本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。 The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

Claims (8)

  1. 　クラックが無く、０．３８ｃｍ２以上の断面積を有し、酸素を含むことを特徴とするリチウム含有酸化物結晶。 A lithium-containing oxide crystal characterized by having no cracks, having a cross section of 0.38 cm 2 or more, and containing oxygen.
  2. 　請求項１に記載のリチウム含有酸化物結晶であって、
    前記断面積が１．７６ｃｍ２以上１００ｃｍ２以下であることを特徴とするリチウム含有酸化物結晶。     The lithium-containing oxide crystal according to claim 1.
    Lithium-containing oxide crystal wherein the cross-sectional area is 1.76 cm 2 or more 100 cm 2 or less.
  3. 　請求項１または２に記載のリチウム含有酸化物結晶であって、
    　長手方向の寸法を有し、前記長手方向の寸法が１０ｍｍ以上であることを特徴とするリチウム含有酸化物結晶。     The lithium-containing oxide crystal according to claim 1 or 2.
    A lithium-containing oxide crystal having a longitudinal dimension and having a longitudinal dimension of 10 mm or more.
  4. 　請求項１から３の何れか一つに記載のリチウム含有酸化物結晶の少なくとも一部を用いることを特徴とする電池。 A battery characterized in that at least a part of the lithium-containing oxide crystal according to any one of claims 1 to 3 is used.
  5. 　酸素を含むリチウム含有酸化物結晶原料の少なくとも一部を溶融して溶融部を形成する溶融部形成工程と、
    前記溶融部からリチウム含有酸化物結晶を成長形成する成長工程を有し、
    前記成長工程における雰囲気の露点は－７０℃以上－３５℃以下の範囲であり、
    前記リチウム含有酸化物結晶は０．３８ｃｍ２以上の断面積を有することを特徴とするリチウム含有酸化物結晶の製造方法。     A melting part forming step of melting at least a part of a lithium-containing oxide crystal raw material containing oxygen to form a melting part, and
    It has a growth step of growing and forming lithium-containing oxide crystals from the molten portion.
    The dew point of the atmosphere in the growth step is in the range of −70 ° C. or higher and −35 ° C. or lower.
    A method for producing a lithium-containing oxide crystal, wherein the lithium-containing oxide crystal has a cross section of 0.38 cm 2 or more.
  6. 　請求項５に記載のリチウム含有酸化物結晶の製造方法であって、
    　前記露点を－７０℃以上－４０℃以下の範囲内に設定し、
    　前記溶融部から１．７６ｃｍ２以上１００ｃｍ２以下の面積を有する前記リチウム含有酸化物結晶を成長形成することを特徴とするリチウム含有酸化物結晶の製造方法。     The method for producing a lithium-containing oxide crystal according to claim 5.
    The dew point is set within the range of −70 ° C. or higher and −40 ° C. or lower.
    Method for producing a lithium-containing oxide crystals, characterized in that said lithium-containing oxide crystal growth form having an area of 1.76 cm 2 or more 100 cm 2 or less from the molten portion.
  7. 　請求項５または６に記載のリチウム含有酸化物結晶の製造方法であって、
    　前記露点を－６５℃以上－４５℃以下の範囲内に設定し、
    　前記溶融部から１０ｍｍ以上の長手方向の寸法で前記リチウム含有酸化物結晶を成長形成することを特徴とするリチウム含有酸化物結晶の製造方法。     The method for producing a lithium-containing oxide crystal according to claim 5 or 6.
    Set the dew point within the range of -65 ° C or higher and -45 ° C or lower.
    A method for producing a lithium-containing oxide crystal, which comprises growing and forming the lithium-containing oxide crystal in a dimension of 10 mm or more in the longitudinal direction from the molten portion.
  8. 　請求項５から７の何れか一つに記載のリチウム含有酸化物結晶の製造方法であって、
    前記成長工程は、ＣＺ法又はＥＦＧ法を用いることを特徴とするリチウム含有酸化物結晶の製造方法。     The method for producing a lithium-containing oxide crystal according to any one of claims 5 to 7.
    The growth step is a method for producing a lithium-containing oxide crystal, which comprises using a CZ method or an EFG method.
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Citations (3)

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Publication number Priority date Publication date Assignee Title
JP2005119950A (en) * 2003-09-26 2005-05-12 Shin Etsu Chem Co Ltd Method for manufacturing monopolarized lithium tantalate crystal and monopolarized lithium tantalate crystal
JP2006124223A (en) * 2004-10-28 2006-05-18 Shin Etsu Chem Co Ltd Method for manufacturing oxide single crystal
WO2017203954A1 (en) * 2016-05-26 2017-11-30 国立研究開発法人産業技術総合研究所 Lowly symmetric garnet-related structured solid electrolyte and lithium secondary battery

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005119950A (en) * 2003-09-26 2005-05-12 Shin Etsu Chem Co Ltd Method for manufacturing monopolarized lithium tantalate crystal and monopolarized lithium tantalate crystal
JP2006124223A (en) * 2004-10-28 2006-05-18 Shin Etsu Chem Co Ltd Method for manufacturing oxide single crystal
WO2017203954A1 (en) * 2016-05-26 2017-11-30 国立研究開発法人産業技術総合研究所 Lowly symmetric garnet-related structured solid electrolyte and lithium secondary battery

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