WO2018025649A1 - Pile au lithium tout solide - Google Patents

Pile au lithium tout solide Download PDF

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Publication number
WO2018025649A1
WO2018025649A1 PCT/JP2017/026286 JP2017026286W WO2018025649A1 WO 2018025649 A1 WO2018025649 A1 WO 2018025649A1 JP 2017026286 W JP2017026286 W JP 2017026286W WO 2018025649 A1 WO2018025649 A1 WO 2018025649A1
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Prior art keywords
positive electrode
solid
oriented
electrode plate
lithium
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PCT/JP2017/026286
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English (en)
Japanese (ja)
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雄樹 藤田
小林　伸行
幸信 由良
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日本碍子株式会社
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Priority to JP2018531828A priority Critical patent/JP6906524B2/ja
Publication of WO2018025649A1 publication Critical patent/WO2018025649A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • 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
    • 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
    • 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
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
    • 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
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of 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
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • 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.
  • Patent Document 1 Japanese Patent No. 3427570
  • Patent Document 2 Japanese Patent No. 5775444 discloses a nonaqueous electrolyte battery electrode having a sheet-like conductive core material, a carbon layer, an active material layer, and a coating layer. It is disclosed that the material layer includes a ceramic film having a thickness of 20 to 120 ⁇ m formed of a sintered body of a transition metal oxide capable of occluding and / or releasing lithium.
  • Patent Document 3 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
  • LiPON 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.
  • a thin film lithium secondary battery is manufactured by forming a positive electrode layer made of lithium cobaltate on a substrate, forming a solid electrolyte layer on the positive electrode layer, and forming metal lithium on the solid electrolyte layer. This is done by forming a negative electrode layer.
  • a positive electrode active material composed of a lithium composite oxide having a layered rock salt structure the diffusion of lithium ions (Li + ) therein is a plane parallel to the (003) plane (ie, the (003) plane).
  • lithium ions enter and exit in crystal planes other than the (003) plane (for example, (101) plane or (104) plane). Therefore, in this type of positive electrode active material, a surface that comes into contact with the electrolyte more in a crystal plane (a plane other than the (003) plane, for example, the (101) plane or the (104) plane) on which lithium ions can enter and exit satisfactorily. Attempts have been made to improve the battery characteristics of lithium secondary batteries by exposing them to the above.
  • Patent Document 4 (WO 2010/074304), a sheet containing Co 3 O 4 particles by firing a green sheet (h00) face is oriented parallel to the sheet surface including Co 3 O 4 It is disclosed that a LiCoO 2 ceramic sheet (positive electrode active material film) having a (104) plane oriented parallel to the sheet surface is produced by forming and then introducing Li.
  • the orientation direction of each primary particle exposed on the plate surface can be set to the [101] direction or the [104] direction. If the orientation direction of the primary particles is the [101] direction, the (003) plane of the primary particles is inclined by about 75 degrees with respect to the plate surface. If the orientation direction of the primary particles is the [104] direction, the (003) plane of the primary particles is inclined by about 48 degrees with respect to the plate surface.
  • the lithium composite oxide with a layered rock salt structure has the property that the interlayer distance increases as lithium ions are released. Dimension changes with. For this reason, tensile stress is generated with respect to the solid electrolyte layer, which may cause an electrical short circuit or an increase in resistance due to breakage or peeling of the solid electrolyte layer or generation of cracks.
  • stress is generated between the grains along with charge / discharge, which may cause deterioration of charge / discharge performance.
  • a conductive agent having a sufficiently low resistance in the in-plane direction is uniformly formed on the back surface of the positive electrode plate as a current collecting layer to enable uniform charge and discharge in the plate surface direction of the positive electrode plate. It is possible.
  • a metal film having a thickness of 10 ⁇ m or more is formed on the surface of the positive electrode plate by baking or the like, or a thickness of 5 ⁇ m or more is formed on the surface of the positive electrode plate.
  • a special configuration is required, such as bonding the metal foil (current collector foil) through a conductive adhesive.
  • the positive electrode plate expands and contracts due to charge / discharge, and the contact resistance increases due to deterioration factors such as interfacial peeling during use at a deep charge / discharge depth or for a long period of time. Invited, therefore, there was a problem with reliability.
  • a positive electrode plate made of a dense and thick ceramic sintered body is used as the positive electrode of the all-solid-state lithium battery, further improvement in long-term reliability is desired.
  • the object of the present invention is to improve the resistance increase rate during repeated use while adopting a thick positive electrode plate made of a sintered body, and therefore the long-term reliability is greatly improved.
  • the object is to provide an all-solid-state lithium battery having excellent battery characteristics.
  • a self-supporting oriented positive electrode plate having a thickness of 20 ⁇ m or more made of an oriented sintered body, wherein the oriented sintered body comprises a plurality of lithium composite oxides having a layered rock salt structure.
  • An oriented positive electrode plate comprising crystal grains, wherein the plurality of crystal grains have a (003) plane oriented parallel to a plate surface of the oriented positive electrode plate;
  • a solid electrolyte layer provided on the oriented positive electrode plate and made of a lithium ion conductive material;
  • a positive electrode current collector which is a metal foil having a thickness of 5 ⁇ m or more and 30 ⁇ m or less, which is in full contact with the surface opposite to the solid electrolyte layer of the oriented positive electrode plate in a non-adhesive state not containing an adhesive;
  • An all-solid lithium battery is provided.
  • FIG. 8 is a schematic cross-sectional view for conceptually explaining the lithium ion conduction direction and the expansion / contraction method in the oriented positive electrode plate used in the present invention as shown in FIG. 7. It is a SEM image which shows an example of a cross section perpendicular
  • FIG. 9B is an EBSD image of a cross section of the aligned positive electrode plate in a measurement region specified by a rectangular frame in FIG. 9A.
  • FIGS. 1 and 2 schematically show an example of an all solid lithium battery according to the present invention.
  • An all solid lithium battery 10 shown in FIGS. 1 and 2 includes an oriented positive electrode plate 12, a solid electrolyte layer 14, a negative electrode layer 16, and a positive electrode current collector 20.
  • An all-solid lithium battery 10 shown in FIG. 1 includes two unit batteries each composed of an oriented positive electrode plate 12, a solid electrolyte layer 14, a negative electrode layer 16, and a positive electrode current collector 20 via a negative electrode current collector 24. It has a configuration in which the layers are vertically stacked in parallel. However, the present invention is not limited to this, and may be configured by one unit cell 10 ′ as schematically shown in FIG.
  • the oriented positive electrode plate 12 is a self-supporting plate having a thickness of 20 ⁇ m or more made of an oriented sintered body, and the oriented sintered body includes a plurality of crystal grains composed of a lithium composite oxide having a layered rock salt structure. These crystal grains have a (003) plane oriented parallel to the plate surface of the oriented positive electrode plate 12.
  • the solid electrolyte layer 14 is provided on the oriented positive electrode plate 12 and is made of a lithium ion conductive material.
  • the negative electrode layer 16 is a layer provided on the solid electrolyte layer 14 and containing lithium.
  • the positive electrode current collector 20 is a metal foil having a thickness of 5 ⁇ m or more and 30 ⁇ m or less, and is in full contact with the surface opposite to the solid electrolyte layer 14 of the oriented positive electrode plate 12 in a non-adhesive state not containing an adhesive. Yes.
  • the alignment positive electrode plate is brought into full contact with a thin positive electrode current collector in a non-adhesive state without an adhesive. The rate of increase in resistance during repeated use can be significantly reduced, and as a result, long-term reliability can be greatly improved.
  • the positive electrode current collector 20 which is a metal foil having a thickness of 5 ⁇ m or more and 30 ⁇ m or less, is a flexible thin conductive material, and therefore can be uniformly adhered to the entire surface of the oriented positive electrode plate 12.
  • the positive electrode current collector 20 and the alignment positive electrode plate 12 which are metal foils are in point contact with each other microscopically, current collection unevenness may occur in the plane.
  • the distance between the contact points is significantly smaller than the thickness of the alignment positive electrode plate 12 (20 ⁇ m or more), unevenness of current collection due to misalignment from the contact point causes Li ion diffusion in the thickness direction of the alignment positive electrode plate 12. Therefore, uneven charging / discharging within the plate surface can be eliminated.
  • the aligned positive electrode plate 12 collects current with the positive electrode current collector 20 in an adhesive-free non-adhered state
  • the positive electrode current collector 20 does not basically follow even when the aligned positive electrode plate 12 expands and contracts. Even if this is not the case, since the positive electrode current collector 20 is a thin metal foil, it can follow expansion and contraction to some extent due to its ductility. In any case, the oriented positive electrode plate 12 can move relative to the positive electrode current collector 20 while ensuring contact with the positive electrode current collector 20 according to expansion and contraction. For this reason, the interface stress between the oriented positive electrode plate 12 and the positive electrode current collector 20 does not occur, and therefore, deterioration factors such as interface peeling can be eliminated.
  • long-term reliability is considered to be greatly improved. That is, interfacial peeling caused by expansion and contraction of the alignment positive electrode plate 12 due to charge and discharge and an increase in contact resistance caused thereby can be significantly suppressed, and long-term reliability can be improved.
  • battery characteristics such as rate characteristics and cycle characteristics are also improved by adopting an oriented positive plate whose (003) plane is oriented parallel to the plate surface of the oriented positive plate.
  • the positive current collector 20 is a metal foil.
  • the thickness of the metal foil is 5 to 30 ⁇ m, preferably 5 to 25 ⁇ m, more preferably 10 to 25 ⁇ m, and still more preferably 10 to 20 ⁇ m. By increasing the thickness as described above, a sufficient current collecting function can be ensured.
  • the positive electrode current collector 20 is entirely in contact with the surface of the oriented positive electrode plate 12 opposite to the solid electrolyte layer 14 in a non-adhesive state that does not contain an adhesive. For this reason, since it is rich in flexibility when it is a very thin metal foil as described above, it becomes easy to adhere to the entire surface of the alignment positive electrode plate 12 uniformly.
  • the metal constituting the positive electrode current collector 20 is not particularly limited as long as it does not react with the aligned positive electrode plate 12, and may be an alloy.
  • Preferred examples of such metals include stainless steel, aluminum, copper, platinum, and nickel, and more preferably stainless steel and nickel.
  • the positive electrode current collector 20 also serves as a positive electrode exterior material that covers the outer side of the aligned positive electrode plate 12.
  • the positive electrode current collector 20 also serves as a positive electrode exterior material that covers the outer side of the aligned positive electrode plate 12.
  • two unit cells are stacked in parallel symmetrically via a single negative electrode current collector 24 to expose the positive electrode current collector 20 to the outside of the all-solid-state lithium battery 10. It is good also as a structure.
  • the negative electrode current collector 24 can function as a current collector common to two adjacent unit batteries.
  • the positive electrode current collector 20 is preferably pressed against the aligned positive electrode plate 12. Since the metal foil which is the positive electrode current collector 20 is a flexible thin conductive material, a large number of contact points between the positive electrode current collector 20 and the alignment positive electrode plate 12 can be secured by pressing, and the alignment positive electrode plate 12 can be secured. Can be more uniformly adhered to the entire surface. Thereby, a desirable current collecting effect can be obtained while being in an adhesive-free non-adhered state.
  • the method of pressing is not particularly limited. For example, the pressing is performed from the outside of the positive electrode current collector 20 toward the alignment positive electrode plate 12 using a flexible pressing member (for example, foam metal) that does not damage the positive electrode current collector 20.
  • a method, a method using a pressure difference between the inside and outside of the positive electrode current collector 20, or the like can be employed.
  • the positive current collector 20 is pressed against the oriented positive electrode plate 12 due to a difference in internal and external pressures of the positive current collector 20. That is, it is only necessary that the orientation positive electrode plate 12 side of the positive electrode current collector 20 is depressurized or the side opposite to the orientation positive electrode plate 12 of the positive electrode current collector 20 is pressurized.
  • the metal foil as the positive electrode current collector 20 is a flexible thin conductive material according to the pressing using the internal and external pressure difference of the positive electrode current collector 20, the surface of the oriented positive electrode plate 12 Thus, the contact can be made at more contact points, and the current collecting effect can be further enhanced.
  • the positive electrode current collector 20 and the aligned positive electrode plate 12 are in a non-adhered state. This means that the positive electrode current collector 20 and the aligned positive electrode plate 12 are partially (for example, part of the outer peripheral portion of the aligned positive electrode plate 12) and are adhesive resins. It is not excluded that it is fixed by, for example. Such a resin is used for the purpose of temporary adhesion to prevent misalignment of the oriented positive electrode plate when assembling the battery.
  • the laminate including the oriented positive electrode plate 12, the solid electrolyte layer 14, and the negative electrode layer 16 is packaged or sealed with an exterior material.
  • the positive electrode current collector 20 constitutes a part of the exterior material, and the accommodation space of the laminate that is packaged or sealed with the exterior material is decompressed.
  • the storage space can be depressurized, for example, by packaging or sealing with an exterior material under reduced pressure, or by degassing the storage space after packaging or sealing the exterior material.
  • the metal foil that is the positive electrode current collector 20 is a flexible thin conductive material, the contact point of the positive electrode current collector 20 with the surface of the aligned positive electrode plate 12 is increased by reducing the storage space.
  • the degree of vacuum may be set as appropriate based on the flexibility of the metal and the strength of the laminate.
  • the positive electrode current collector 20 may include a carbon film on the surface on the solid electrolyte layer 14 side.
  • the thickness of the carbon film is preferably 0.01 ⁇ m to 5 ⁇ m, more preferably 0.01 ⁇ m to 1 ⁇ m, and still more preferably 0.05 ⁇ m to 0.5 ⁇ m.
  • the oriented positive electrode plate 12 is a self-supporting plate made of an oriented sintered body and having a thickness of 20 ⁇ m or more.
  • the oriented sintered body includes a plurality of crystal grains composed of a lithium composite oxide having a layered rock salt structure.
  • the lithium composite oxide is Li x MO 2 (0.05 ⁇ x ⁇ 1.10, M is at least one transition metal, and M is typically selected from Co, Ni, and Mn. Oxide containing a species or more).
  • the lithium composite oxide typically has a layered rock salt structure.
  • the layered rock salt structure is a crystal structure in which lithium layers and transition metal layers other than lithium are alternately stacked with oxygen layers in between, that is, the transition metal ion layers and lithium single layers are alternately arranged via oxide ions.
  • an ⁇ -NaFeO 2 type structure, ie a structure in which transition metals and lithium are regularly arranged in the [111] axis direction of a cubic rock salt type structure.
  • lithium composite oxides include lithium cobaltate, lithium nickelate, lithium manganate, nickel / lithium manganate, nickel / lithium cobaltate, cobalt / nickel / lithium manganate, cobalt / lithium manganate, etc. .
  • the lithium composite oxide includes Mg, Al, Si, Ca, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Ag, Sn, Sb, Te, Ba. , Bi, W, etc. may contain one or more elements.
  • a particularly preferable lithium composite oxide is lithium cobalt oxide. That is, it is particularly preferable that the crystal grains are lithium cobalt oxide crystal grains.
  • the (003) plane of the plurality of crystal grains contained in the oriented sintered body is oriented parallel to the plate surface of the oriented positive electrode plate. It is not necessary for all of the crystal grains contained in the oriented sintered body to be parallel, but most of them are preferably parallel.
  • “parallel” is not limited to perfect parallel (that is, 0 degree), but includes an angle equivalent to parallel, which should be substantially parallel.
  • the angle formed by the (003) plane is within 30 degrees, more typically within 25 degrees, even more typically within 20 degrees, particularly typically within 15 degrees, particularly typically within 10 degrees, most typically Specifically, it means within 5 degrees.
  • the layered rock salt structure lithium composite oxide has the property that the interlayer distance increases as lithium ions are released. That is, as conceptually shown in FIG.
  • the lithium composite oxide crystal grains 11 as primary particles have a lithium ion movement direction LiD parallel to the (003) plane, and the expansion / contraction direction perpendicular to the (003) plane.
  • LiD lithium ion movement direction
  • expansion / contraction direction perpendicular to the (003) plane.
  • ECD expansion / contraction direction
  • the oriented positive electrode plate 12 employed in the present invention has the (003) plane parallel to the plate surface as illustrated in the fracture surface SEM image of FIG. 7 and conceptually depicted in FIG.
  • the expansion in the surface direction of the aligned positive electrode plate 12 accompanying the release of lithium ions is reduced.
  • the tensile stress to the solid electrolyte layer 14 due to the expansion and contraction of the oriented positive electrode plate 12 at the time of charging / discharging is reduced, and an electrical short circuit or an increase in resistance due to the breakage or peeling of the solid electrolyte layer 14 or the occurrence of cracks is prevented. Can lead to improved cycle characteristics.
  • the angle of the crystal grain 11 is drawn larger than that shown in FIG. 7, but the crystal grain 11 is parallel to the same degree as in FIG. It should be understood as meaning.
  • the lithium ion moving distance is the same as that of the conventional aligned positive electrode plate 12 shown in FIG. It is much longer than the lithium ion movement distance. Nevertheless, battery characteristics such as rate characteristics and cycle characteristics are good, and this is a surprising finding that is totally unexpected.
  • FIG. 9A shows an SEM image showing an example of a cross section perpendicular to the plate surface of the oriented positive electrode plate
  • FIG. 9B shows an EBSD image of a cross section of the oriented positive electrode plate in the measurement region specified by the rectangular frame in FIG. 9A.
  • the orientation angle of each crystal grain is represented by color shading, and the darker the color, the smaller the orientation angle.
  • the orientation angle is an inclination angle formed by the (003) plane of each crystal grain with respect to the plate surface direction.
  • the portions displayed in black inside the oriented positive plate are pores.
  • the average value of the orientation angles of crystal grains (primary particles) (hereinafter referred to as “average orientation angle”) is more than 0 ° and not more than 30 °.
  • the average orientation angle of crystal grains or primary particles is obtained by arithmetically averaging the orientation angles of about 30 primary particles selected by the method described later in the EBSD image in the cross section of the orientation positive electrode plate as shown in FIG. 9B. can get.
  • the average orientation angle of the primary particles is preferably 30 ° or less and more preferably 25 ° or less in consideration of further improving the rate characteristics.
  • the average orientation angle of the primary particles is preferably 2 ° or more, more preferably 5 ° or more, considering rate characteristics.
  • the primary particles used for calculation of the average degree of orientation are those of the primary particles in the image when the observation magnification is set such that about 30 primary particles are included in the image in the EBSD image in the cross section of the positive electrode plate. All the particles whose outer periphery is completely included are included. Note that primary particles having a maximum ferret diameter of less than 0.5 ⁇ m are not counted.
  • the angle of the (003) plane with respect to the plate surface among the crystal grains included in the analyzed cross section exceeds 0 °.
  • the total area of crystal grains of 30 ° or less is 70% or more with respect to the total area of crystal grains included in the cross section. That is, in the EBSD image as shown in FIG. 9B, the total area of primary particles whose orientation angle is greater than 0 ° and 30 ° or less (hereinafter referred to as “low angle primary particles”) is used for calculating the average orientation angle.
  • the total area of the primary particles is preferably 70% or more.
  • the total area of the low-angle primary particles is preferably more than 70%, more preferably 80% with respect to the total area of about 30 primary particles used for calculating the average orientation angle.
  • the above is more preferable.
  • the total area of the low-angle primary particles having an orientation angle of 20 ° or less is more preferably 50% or more with respect to the total area of about 30 primary particles used for calculation of the average orientation angle. .
  • the total area of the low-angle primary particles having an orientation angle of 10 ° or less is more preferably 15% or more with respect to the total area of 30 primary particles used for calculating the average orientation angle.
  • the thickness of the alignment positive electrode plate 12 is preferably 20 ⁇ m or more, more preferably 30 ⁇ m or more, from the viewpoint of increasing the active material capacity per unit area and ensuring a self-supporting form free of a substrate. More preferably, it is 40 ⁇ m or more, particularly preferably 50 ⁇ m or more, and most preferably 55 ⁇ m or more.
  • the upper limit of the thickness is preferably 100 ⁇ m or less, more preferably 90 ⁇ m or less, still more preferably 80 ⁇ m or less, and particularly preferably from the viewpoint of reducing deterioration of battery characteristics (particularly increase in resistance value) due to repeated charge / discharge. 70 ⁇ m or less.
  • the size of the oriented positive electrode plate is preferably 5 mm ⁇ 5 mm square or more, more preferably 10 mm ⁇ 10 mm to 100 mm ⁇ 100 mm square, and further preferably 20 mm ⁇ 20 mm to 200 mm ⁇ 200 mm square. if, preferably 25 mm 2 or more, more preferably 100 ⁇ 10000 mm 2, more preferably from 400 ⁇ 40000 mm 2.
  • the crystal grains are preferably lithium cobaltate crystal grains.
  • LiCoO 2 constituting the lithium cobaltate crystal grains has a layered rock salt structure, but the oriented sintered plate used in the present invention is typically a plate in which the (003) plane of lithium cobaltate is an oriented positive plate. It is oriented parallel to the surface. This is because the ratio of the diffraction peak intensity due to the (003) plane to the diffraction peak intensity due to the (104) plane when taking the XRD profile of the plate surface is larger than that of the XRD profile of the pulverized powder. Can be judged.
  • the lithium cobalt oxide oriented sintered plate is Mg, Al, Si, Ca, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Sr, Y, and the like within the scope of the present invention.
  • One or more elements such as Zr, Nb, Mo, Ag, Sn, Sb, Te, Ba, Bi, etc. are further doped or equivalent (for example, partial solid solution, segregation, coating, or adhesion to the surface layer of crystal grains) ) May contain a trace amount.
  • the density of the sintered body constituting the oriented positive electrode plate 12 is preferably 90% or more, more preferably 90 to 98%, still more preferably 92 to 98%, and particularly preferably 92 to 95%.
  • the density can be calculated by measuring the bulk density of the sintered body by the Archimedes method and dividing the bulk density by the true density. Alternatively, the density may be calculated by performing SEM observation at 1000 magnifications after CP polishing of the cross section of the aligned positive electrode plate 12, and binarizing the obtained SEM image. From the viewpoint of capacity and energy density, it is basically desirable that the 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 considered that this is because the dense positive electrode plate 12 can be appropriately expanded and contracted as lithium is deinserted and the stress can be relaxed.
  • the oriented positive electrode plate 12 is preferably provided with a conductive film 12a having a thickness of 0.01 ⁇ m or more and less than 5 ⁇ m on the surface opposite to the solid electrolyte layer 14 (surface on the positive electrode current collector 20 side).
  • the conductive film 12a is preferably made of metal and / or carbon. When the conductive film 12a is made of a metal, the conductive film 12a has a low electron conduction resistance with the positive electrode current collector 20 and the alignment positive electrode plate 12 and is a layer made of a metal that does not adversely affect the characteristics of the alignment positive electrode plate 12, in particular.
  • preferred examples include an Au sputtered layer and a Si sputtered layer.
  • a carbon layer may be used instead of a metal conductive film such as an Au sputter layer.
  • the thickness of the conductive film 12a is 0.01 ⁇ m or more and less than 5 ⁇ m, preferably 0.02 ⁇ m or more and 2 ⁇ m or less, more preferably 0.02 ⁇ m or more and 1 ⁇ m or less, and further preferably 0.04 ⁇ m or more and 1 ⁇ m or less.
  • the lithium ion conductive material constituting the solid electrolyte layer 14 is a garnet ceramic material, a nitride ceramic material, a perovskite ceramic material, a phosphate ceramic material, a sulfide ceramic material, or a polymer material.
  • it is at least one selected from the group consisting of garnet-based ceramic materials, nitride-based ceramic materials, perovskite-based ceramic materials, and phosphate-based ceramic materials.
  • garnet based ceramic materials include Li—La—Zr—O based materials (specifically, Li 7 La 3 Zr 2 O 12 etc.), Li—La—Ta—O based materials (specifically, Li 7 La 3 Ta 2 O 12 etc.).
  • nitride ceramic material is Li 3 N.
  • perovskite ceramic materials include Li—La—Zr—O based materials (specifically, LiLa 1-x Ti x O 3 (0.04 ⁇ x ⁇ 0.14), etc.).
  • phosphate ceramic materials include lithium phosphate, nitrogen-substituted lithium phosphate (LiPON), Li—Al—Ti—PO, Li—Al—Ge—PO, and Li—Al—Ti—.
  • Si—P—O specifically, Li 1 + x + y Al x Ti 2 ⁇ x Si y P 3 ⁇ y O 12 (0 ⁇ x ⁇ 0.4, 0 ⁇ y ⁇ 0.6), etc. may be mentioned.
  • the lithium ion conductive material constituting 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 .
  • 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 having this kind of composition is called an LLZ crystal structure, which is referred to as CSD (Cambridge Structure Database) X-ray diffraction file No. 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 manufactured according to a known method or by appropriately modifying it.
  • 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 .
  • 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 0.1 mm, more preferably 0.001 mm to 0.05 mm, and still more preferably, from the viewpoint of charge / discharge rate characteristics and mechanical strength. Is 0.002 to 0.02 mm, particularly preferably 0.003 to 0.01 mm.
  • various particle jet coating methods, solid phase methods, solution methods, and gas phase 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 in the process or formation of a high resistance layer by reaction with an oriented 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.
  • 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.
  • PLD laser deposition
  • PVD evaporation condensation
  • CVD gas phase reaction method
  • MBE molecular beam epitaxy
  • the sputtering method is particularly preferable because there is little composition deviation and a film with relatively high adhesion can be easily obtained.
  • the interface between the oriented 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 oriented 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 coating film can exist at the interface between the oriented positive electrode plate 12 and the solid electrolyte layer 14, but the thickness of the coating film is extremely thin, for example, 20 nm or less.
  • Negative electrode layer The negative electrode layer 16 is a layer containing lithium and is typically composed of lithium metal.
  • the negative electrode layer 16 may be formed by placing lithium metal in the form of a foil on the solid electrolyte layer 14 or the negative electrode current collector 24, or may be formed on the solid electrolyte layer 14 or the negative electrode current collector 24.
  • the thin film can be formed by a vacuum deposition method, a sputtering method, a CVD method, or the like to form a lithium metal layer.
  • the dimensions of the negative electrode layer 16 are not particularly limited, but the thickness is preferably 10 ⁇ m or more, more preferably 50 to 10 ⁇ m, from the viewpoint of securing a large amount of lithium in the all-solid lithium battery 10 with the adoption of the thick oriented positive electrode plate 12. More preferably, it is 40 to 10 ⁇ m, particularly preferably 20 to 10 ⁇ m.
  • an intermediate layer may be interposed between the negative electrode layer 16 and the solid electrolyte layer 14. That is, the all-solid-state lithium battery 10 can further include an intermediate layer containing a metal that can be alloyed with lithium on the surface of the solid electrolyte layer 14 on the negative electrode layer 16 side.
  • a metal alloyed with lithium, an oxide-based material, or the like can be used as a constituent material of the intermediate layer. In this way, even when subjected to a process involving heating such as a reflow soldering process (for example, a process performed at a temperature of 200 ° C. or higher), the melting of lithium metal and the like is significantly suppressed, and therefore an internal short circuit And peeling of the negative electrode layer can be effectively prevented.
  • Metals that can be alloyed with lithium are Al (aluminum), Si (silicon), Zn (zinc), Ga (gallium), Ge (germanium), Ag (silver), Au (gold), Pt (platinum), Cd. It is preferable to include at least one selected from the group consisting of (cadmium), In (indium), Sn (tin), Sb (antimony), Pb (lead), and Bi (bismuth), and more preferably Au ( It contains at least one selected from the group consisting of gold), In (indium), Si (silicon), Sn (tin), Zn (zinc), and Al (aluminum).
  • a preferable metal alloyable with lithium may include at least one selected from Au (gold) and In (indium).
  • the metal that can be 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, a sputtering method, or an evaporation method.
  • the dimension of the intermediate layer is not particularly limited, but the thickness is preferably 0.05 to 1 ⁇ m, more preferably 0.05 to 0.5 ⁇ m, and still more preferably 0.08, from the viewpoint of promoting alloying during heating.
  • the thickness is from 0.2 to 0.2 ⁇ m, particularly preferably from 0.1 to 0.15 ⁇ m.
  • middle layer since the material illustrated as an intermediate
  • the end insulating portion 18 may be provided so as to insulate the end portion of the solid electrolyte layer 14.
  • the end insulating portion 18 preferably includes an organic polymer material that can be adhered or adhered to the solid electrolyte layer 14.
  • the organic polymer material is preferably at least one selected from the group consisting of a binder, a hot melt resin, and an adhesive.
  • the binder include a cellulose resin, an acrylic resin, and a combination thereof.
  • the heat fusion resin include a fluorine resin, a polyolefin resin, and any combination thereof.
  • the hot-melt resin is preferably provided in the form of a heat-sealing film as will be described later.
  • a preferable example of the adhesive is a thermosetting adhesive using a thermosetting resin such as an epoxy resin. Accordingly, it can be said that the organic polymer material is preferably at least one selected from the group consisting of a cellulose resin, an acrylic resin, a fluorine resin, a polyolefin resin, and an epoxy resin.
  • Examples of the cellulose resin include carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose butyrate, cellulose acetate butyrate, and the alkali metal salts and ammonium salts described above.
  • Examples of the acrylic resin include polyacrylic acid esters, polyacrylic acid salts, and maleic anhydride modified products, maleic acid modified products and fumaric acid modified products thereof.
  • fluororesins examples include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP). ), Polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride copolymer, hexafluoropropylene / vinylidene fluoride copolymer, and maleic anhydride-modified products thereof, maleic acid Examples include modified products and fumaric acid modified products. Examples of the polyolefin-based resin include polyethylene, polypropylene, cycloolefin polymer, and maleic anhydride modified products, maleic acid modified products and fumaric acid modified products thereof.
  • the end insulating portion 18 is preferably formed by applying a liquid or slurry containing an organic polymer material (preferably a binder) and optionally a filler or the like.
  • a liquid or slurry application method include a dispensing method, a screen printing method, a spray method, a stamping method, and the like.
  • the negative electrode current collector 24 is preferably provided outside the negative electrode current collector negative electrode layer 16.
  • the negative electrode current collector 24 may also serve as a negative electrode exterior material that covers the outside of the negative electrode.
  • two unit cells are stacked vertically and symmetrically via one positive current collector 20 to form a negative current collector 24. May be exposed to the outside of the all-solid-state lithium battery.
  • the positive electrode current collector 20 can function as a current collector common to two adjacent unit batteries.
  • the negative electrode current collector 24 may be made of the same or different material as the positive electrode current collector 20, but is preferably made of the same kind of material.
  • the metal constituting the negative electrode current collector 24 is not particularly limited as long as it does not react with the negative electrode layer 16 and may be an alloy. Preferred examples of such metals include stainless steel, aluminum, copper, platinum, and nickel, and more preferably stainless steel.
  • the negative electrode current collector 24 is preferably a metal plate or a metal foil, and more preferably a metal foil. Therefore, it can be said that the most preferred current collector is a stainless steel foil.
  • the preferred thickness of the metal foil is 1 to 30 ⁇ m, more preferably 5 to 25 ⁇ m, and still more preferably 10 to 20 ⁇ m.
  • the end-sealing portion all solid lithium battery 10 is not coated with the positive electrode current collector 20 and the negative electrode current collector 24, and is aligned with the positive electrode plate 12, the solid electrolyte layer 14, the negative electrode layer 16, and (if present) It is preferable that an end sealing portion 26 made of a sealing material for sealing the exposed portion of the end insulating portion 18 is further provided. An end sealing portion 26 is provided to expose exposed portions of the oriented positive electrode plate 12, the solid electrolyte layer 14, the negative electrode layer 16, and the end insulating portion 18 that are not covered with the positive electrode current collector 20 and the negative electrode current collector 24. By sealing, excellent moisture resistance (desirably moisture resistance at high temperature) can be ensured.
  • the end sealing portion 26 is made of a sealing material.
  • the sealing material can seal the exposed portion not covered with the positive electrode current collector 20, the negative electrode current collector 24, and the end insulating portion 18 to ensure excellent moisture resistance (preferably moisture resistance at high temperature). If it is a thing, it will not specifically limit. However, it goes without saying that it is desirable that the sealing material ensure electrical insulation between the positive electrode current collector 20 and the negative electrode current collector 24.
  • the sealing material preferably has a resistivity of 1 ⁇ 10 6 ⁇ cm or more, more preferably 1 ⁇ 10 7 ⁇ cm or more, and further preferably 1 ⁇ 10 8 ⁇ cm or more. Such a resistivity can significantly reduce self-discharge.
  • the thickness of the end sealing portion 26 is preferably 10 to 300 ⁇ m, more preferably 15 to 200 ⁇ m, still more preferably 20 to 150 ⁇ m.
  • the intrusion of moisture into the battery can only occur through the end sealing portion 26. This is because moisture is not transmitted when the positive electrode current collector and the negative electrode current collector are made of metal. Therefore, the thinner the end sealing portion 26 (that is, the narrower the entrance of moisture intrusion) is, and the greater the width of the end sealing portion (ie, the longer the path of moisture intrusion), the more the device enters the battery.
  • the amount of moisture is reduced, that is, moisture resistance is improved. From such a viewpoint, it can be said that the thickness within the above range is preferable.
  • the width of the end sealing portion 26 (also referred to as the thickness of the solid electrolyte layer 14 in the layer surface direction) is preferably 0.5 to 3 mm, more preferably 0.7 to 2 mm, and further preferably 1 to 2 mm. It is. When the width is within the above range, the end sealing portion 26 does not become too large, so that the volume energy density of the battery can be secured high.
  • the sealing material is preferably a resin-based sealing material containing a resin.
  • the end sealing portion 26 can be formed at a relatively low temperature (for example, 400 ° C. or lower), and as a result, battery destruction and alteration due to sealing accompanied by heating can be effectively prevented. be able to.
  • the resin preferably has a thermal expansion coefficient of 7 ⁇ 10 ⁇ 6 / ° C. or more, more preferably 9 ⁇ 10 ⁇ 6 to 20 ⁇ 10 ⁇ 6 / ° C., and still more preferably 10 ⁇ 10 ⁇ 6 to 19 ⁇ 10 ⁇ .
  • the resin is preferably an insulating resin.
  • the insulating resin is preferably a resin (adhesive resin that can be bonded with heat, an adhesive, or the like) that can be bonded while maintaining insulating properties.
  • preferable insulating resins include olefin resins, fluorine resins, acrylic resins, epoxy resins, urethane resins, and silicon resins.
  • particularly preferable resins include, as a low moisture-permeable resin sealing material, polypropylene (PP), polyethylene (PE), cycloolefin polymer, and polychlorotrifluoroethylene (PCTFE), and modified maleic anhydrides thereof, Examples thereof include an adhesive resin having a low water permeability and a heat fusion type typified by a maleic acid modified product and a fumaric acid modified product.
  • the insulating resin can be composed of at least one or a plurality of types of laminates. Further, a thermoplastic resin molded sheet or a resin having a reactive adhesive component may be used as at least one kind of insulating resin.
  • the resin-based sealing material may be made of a mixture of a resin (preferably an insulating resin) and an inorganic material.
  • a resin preferably an insulating resin
  • inorganic materials include silica, alumina, zinc oxide, magnesia, calcium carbonate, calcium hydroxide, barium sulfate, mica and talc, and silica is more preferable.
  • a resin-based sealing material made of a mixture of an epoxy resin and silica is preferably exemplified.
  • the end sealing portion 26 may be formed by laminating a resin film on the positive electrode current collector (thermal fusion or bonding via an adhesive), dispensing a liquid resin, or the like. It is preferable that gaps that can be formed between the end side surfaces of the alignment positive electrode plate 12, the solid electrolyte layer 14, and the negative electrode layer 16 and the end sealing portion 26 are sufficiently filled with the end insulating portion 18.
  • the sealing material may be a glass-based sealing material containing glass. It is preferable that the glass-based sealing material contains at least one selected from the group consisting of V, Sn, Te, P, Bi, B, Zn, and Pb from the viewpoint of easily obtaining a desired softening temperature and thermal expansion coefficient. Of course, these elements may be present in the glass in the form of V 2 O 5 , SnO, TeO 2 , P 2 O 5 , Bi 2 O 3 , B 2 O 3 , ZnO, and PbO. However, it is more preferable that the glass-based sealing material does not contain Pb or PbO which can be a harmful substance.
  • the glass-based sealing material preferably has a softening temperature of 400 ° C.
  • the softening temperature is not particularly limited with respect to the lower limit value, but may be, for example, 300 ° C or higher, 310 ° C or higher, or 320 ° C or higher.
  • the end sealing portion 26 can be formed at a relatively low temperature, and as a result, sealing with heating is performed. It is possible to effectively prevent the destruction and alteration of the battery due to the wearing.
  • the glass-based sealing material preferably has a thermal expansion coefficient of 7 ⁇ 10 ⁇ 6 / ° C.
  • the all-solid lithium battery preferably has a thickness of 60 to 5000 ⁇ m, more preferably 70 to 4000 ⁇ m, still more preferably 80 to 3000 ⁇ m, and particularly preferably. Is from 90 to 2000 ⁇ m, most preferably from 100 to 1000 ⁇ m.
  • the oriented positive electrode plate can be made relatively thick, while the current collector also serves as an exterior material, so that the thickness of the entire battery can be made relatively thin.
  • the oriented positive electrode plate or oriented sintered plate used in the all solid lithium battery of the present invention may be produced by any method, but preferably, as exemplified below (1) Production of LiCoO 2 template particles, (2) Production of matrix particles, (3) Production of green sheets, and (4) Production of oriented sintered plates.
  • LiCoO 2 Template Particles Co 3 O 4 raw material powder and Li 2 CO 3 raw material powder are mixed and fired (500 to 900 ° C., 1 to 20 hours) to synthesize LiCoO 2 powder.
  • the obtained LiCoO 2 powder is pulverized to a volume-based D50 particle size of 0.2 ⁇ m to 10 ⁇ m by a pot mill to obtain plate-like LiCoO 2 particles capable of conducting lithium ions in parallel with the plate surface.
  • Such LiCoO 2 particles can be obtained by a method of crushing after growing a green sheet using LiCoO 2 powder slurry, a plate method such as a flux method, hydrothermal synthesis, single crystal growth using a melt, or a sol-gel method.
  • the obtained LiCoO 2 particles are easily cleaved along the cleavage plane. It is to cleave by crushing the LiCoO 2 particles to prepare a LiCoO 2 template particles.
  • Co 3 O 4 raw material powder is used as matrix particles.
  • the volume-based D50 particle size of the Co 3 O 4 raw material powder is not particularly limited and can be, for example, 0.1 to 1.0 ⁇ m, but is preferably smaller than the volume-based D50 particle size of LiCoO 2 template particles.
  • the matrix particles can also be obtained by subjecting a Co (OH) 2 raw material to heat treatment at 500 ° C. to 800 ° C. for 1 to 10 hours.
  • Co (OH) 2 particles or LiCoO 2 particles may be used as matrix particles.
  • the slurry compact is placed on a zirconia setter and subjected to heat treatment (500 ° C. to 900 ° C., 1 to 10 hours) to obtain a sintered plate as an intermediate.
  • the sintered plate is sandwiched between lithium sheets so that the Li / Co ratio is 1.0, and the synthesized lithium sheet is placed on a zirconia setter.
  • the setter is put into an alumina sheath and fired in the atmosphere (700 to 850 ° C., 1 to 20 hours), and then the sintered plate is sandwiched between lithium sheets and further fired (750 to 900 ° C., 1 to 40 Time) to obtain a LiCoO 2 sintered plate.
  • This firing step may be performed in two steps or may be performed once. When firing twice, it is preferable that the first firing temperature is lower than the second firing temperature.
  • Examples A1 to A8 (1) Preparation of LCO template particles Co 3 O 4 raw material powder (volume basis D50 particle size 0.8 ⁇ m, manufactured by Shodo Chemical Co., Ltd.) and Li 2 CO 3 raw material powder (volume basis D50 particle size 2.5 ⁇ m, Honjo) Chemical) was mixed and baked at 800 ° C. to 900 ° C. for 5 hours to synthesize LiCoO 2 raw material powder. At this time, the volume-based D50 particle size of the LiCoO 2 raw material powder was adjusted as shown in Table 1 by adjusting the heat treatment temperature and the Li / Co ratio.
  • the obtained LiCoO 2 powder was pulverized to obtain plate-like LiCoO 2 particles (LCO template particles).
  • LCO template particles plate-like LiCoO 2 particles
  • a pot mill was used, and in Example A3, a wet jet mill was used.
  • the volume-based D50 particle size of the LCO template particles was adjusted as shown in Table 1 by adjusting the grinding time.
  • the aspect ratio of LiCoO 2 template particles were as shown in Table 1.
  • the aspect ratio of LiCoO 2 template particles was measured by observing the particles with SEM.
  • Co 3 O 4 raw material powder (manufactured by Shodo Chemical Industry Co., Ltd.) was used as matrix particles.
  • the volume-based D50 particle size of the matrix particles was as shown in Table 1. However, Example A4 did not use matrix particles.
  • a binder polyvinyl butyral: product number BM-2, manufactured by Sekisui Chemical Co., Ltd.
  • a plasticizer DOP : 4 parts by weight of Di (2-ethylhexyl) phthalate (manufactured by Kurokin Kasei Co., Ltd.) and 2 parts by weight of a dispersant (product name: Leodol SP-O30, manufactured by Kao Corporation) were mixed.
  • the mixture was degassed by stirring under reduced pressure, and a slurry was prepared by adjusting the viscosity to 40960000 cP.
  • the viscosity was measured with an LVT viscometer manufactured by Brookfield.
  • the prepared slurry was formed into a sheet on a PET film by a doctor blade method so that the thickness after drying was 40 ⁇ m at a forming speed of 100 m / h to obtain a green sheet.
  • the synthesized lithium sheet is subjected to secondary firing by placing it on a zirconia setter with the Co 3 O 4 sintered plate sandwiched between the lithium sheets so that the Li / Co ratio is as shown in Table 1.
  • a LiCoO 2 sintered plate Specifically, the zirconia setter was placed in a 90 mm square alumina sheath, held in the atmosphere at 800 ° C. for 5 hours, and then further sandwiched between lithium sheets and fired at 900 ° C. for 20 hours.
  • tungsten boat with lithium metal was prepared.
  • a vacuum deposition apparatus carbon coater SVC-700, manufactured by Sanyu Denshi
  • vapor deposition was performed in which Li was evaporated by resistance heating to form a thin film on the surface of the intermediate layer.
  • the size of the negative electrode layer was set to 9.5 mm square so that the negative electrode layer was within the 10 mm square positive electrode region. In this way, a unit cell was produced in which a Li-deposited film having a thickness of 10 ⁇ m was formed as a negative electrode layer on the solid electrolyte layer.
  • a 20 ⁇ m thick stainless steel foil was cut into a 13 mm square to form a positive electrode current collector. Also, a 1 mm wide frame-shaped modified polypropylene resin film (thickness: 100 ⁇ m) having an outer edge shape of 13 mm square and an 11 mm square hole punched inside thereof was prepared. This frame-shaped resin film was laminated on the outer peripheral portion on the positive electrode current collector plate, and heat-pressed to form an end sealing portion. The unit cell was placed in a region surrounded by the end sealing portion on the positive electrode current collector plate. Similarly to the above, a stainless steel foil having a thickness of 20 ⁇ m was placed on the negative electrode side of the placed unit cell, and heated at 200 ° C. under reduced pressure while applying a load to the end sealing portion. Thus, the end sealing part and the upper and lower two stainless steel foils were bonded together over the entire outer periphery to seal the unit cell. Thus, an all solid lithium battery in a sealed form was obtained.
  • the average orientation angle of the primary particles was calculated by arithmetically averaging the orientation angles of about 30 primary particles selected under the above conditions.
  • the calculation results were as shown in Table 2.
  • the angle formed between the plate surface and the (003) plane is within 30 degrees, more typically within 25 degrees, more typically within 20 degrees, particularly typically within 15 degrees, particularly typical.
  • it includes a plurality of crystal grains (primary particles) within 10 degrees, most typically within 5 degrees, and the (003) plane is oriented parallel to the plate surface of the oriented positive electrode plate. It was confirmed that a plurality of crystal grains were included.
  • the ratio (%) of the total area of primary particles having an orientation angle of more than 0 ° and 30 ° or less to the total area of about 30 primary particles used for calculating the average orientation angle was calculated.
  • the calculation results were as shown in Table 2.
  • the lithium ion battery was charged to 4.2 [V] at a constant current of 0.1 [mA], and then charged to 0.05 [mA] at a constant voltage. And it discharged to 3.0 [V] with a 0.2 [mA] constant current, and measured the discharge capacity W0. Moreover, after charging to 4.2 [V] at a constant current of 0.1 [mA], charging is performed until the current reaches 0.05 [mA] at a constant voltage, and then 3 at a constant current of 2.0 [mA]. The battery was discharged to 0.0 [V], and the discharge capacity W1 was measured. The rate performance was evaluated by dividing W1 by W0.
  • Example B1 (comparison) In this example, the (104) plane is aligned in parallel to the plate surface (that is, the (003) plane is not aligned in parallel to the plate surface), and an all-solid-state in which the aligned positive plate is bonded to the current collector plate. It is the comparative example which produced and evaluated the lithium battery.
  • a binder polyvinyl butyral: product number BM-2, manufactured by Sekisui Chemical Co., Ltd.
  • a plasticizer DOP : 4 parts by weight of di (2-ethylhexyl) phthalate (manufactured by Kurokin Kasei Co., Ltd.) and 2 parts by weight of a dispersant (product name: Leodol SP-O30, Kao Corporation) were mixed.
  • the mixture was defoamed by stirring under reduced pressure and adjusted to a viscosity of 4000 cP.
  • the viscosity was measured with an LVT viscometer manufactured by Brookfield.
  • the slurry prepared as described above was formed into a sheet shape on a PET (polyethylene terephthalate) film so that the thickness after drying was 40 ⁇ m by a doctor blade method to obtain a green sheet.
  • the bulk density of the obtained sintered plate was measured by Archimedes method, and the density was calculated by dividing the bulk density by the true density of lithium cobaltate of 5.05 g / cm 3 . As a result, the density of the sintered plate was 97%.
  • the lithium cobaltate oriented sintered plate is cut into a 10 mm square, and the conductive film surface of the oriented sintered plate is made of an epoxy resin-based conductive adhesive in which conductive carbon is dispersed.
  • a current collector plate positive electrode outer packaging material, 13 mm square, thickness 100 ⁇ m
  • a flat plate-like laminated positive electrode plate / conductive adhesive / positive electrode outer packaging layer plate was obtained.
  • end sealing portion was produced by laminating a modified polypropylene resin film (thickness: 100 ⁇ m) on the end portion of the unit cell (the outer peripheral portion of the positive electrode current collector plate). .
  • the all-solid-state lithium battery was charged to 4.1 V at a constant current of 0.1 mA, and then charged to a current of 0.02 mA at a constant voltage to obtain a charge capacity. Then, it discharged to 3.0V with a 0.1 mA constant current. This operation was repeated 50 times.
  • the internal resistance R of the battery was calculated from the IR drop 10 seconds after the start of discharge, and the internal resistance at the fifth discharge was R 5 and the internal resistance R 50 at the 50th discharge. To R 50 have the value obtained by dividing the rate of change in resistance R 5. When five batteries were produced and evaluated and the average was taken, the resistance change rate was 220%.
  • Example B2 (comparison) In this example, the (104) plane is aligned in parallel with the plate surface (that is, the (003) plane is not aligned in parallel with the plate surface) and the aligned positive plate is not bonded to the current collector plate. It is the comparative example which produced and evaluated the solid lithium battery.
  • a binder polyvinyl butyral: product number BM-2, manufactured by Sekisui Chemical Co., Ltd.
  • a plasticizer DOP : 4 parts by weight of di (2-ethylhexyl) phthalate (manufactured by Kurokin Kasei Co., Ltd.) and 2 parts by weight of a dispersant (product name: Leodol SP-O30, Kao Corporation) were mixed.
  • the mixture was defoamed by stirring under reduced pressure and adjusted to a viscosity of 4000 cP.
  • the viscosity was measured with an LVT viscometer manufactured by Brookfield.
  • the slurry prepared as described above was formed into a sheet shape on a PET (polyethylene terephthalate) film so that the thickness after drying was 40 ⁇ m by a doctor blade method to obtain a green sheet.
  • the battery thus obtained is in a state where the aligned positive electrode plate is not bonded to the current collector plate. That is, in the obtained battery, the positive electrode current collector is entirely in contact with the surface of the oriented positive electrode plate opposite to the solid electrolyte layer in a non-adhesive state that does not contain an adhesive.
  • Example B3 This example is an example in which an all-solid-state lithium battery was prepared and evaluated in a state in which an oriented positive plate with the (003) plane oriented parallel to the plate surface was not bonded to the current collector plate.
  • Example A2 (1) Production of Oriented Positive Electrode Plate
  • an oriented positive plate having a (003) plane oriented parallel to the plate surface was produced according to the conditions shown in Table 1.
  • the characteristics of the obtained oriented positive electrode plate are as shown in Table 2.

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  • Battery Electrode And Active Subsutance (AREA)

Abstract

L'invention porte sur une pile au lithium tout solide ayant de bonnes caractéristiques de cellule, avec laquelle il est possible de réduire de manière significative le taux d'augmentation de la résistance pendant une utilisation répétée, même lorsqu'une plaque d'électrode positive épaisse comprenant un compact fritté est utilisée, ce qui permet d'améliorer considérablement la fiabilité à long terme. Cette pile au lithium tout solide est pourvue : d'une plaque d'électrode positive orientée indépendante ayant une épaisseur de 20 µm ou plus et comprenant un corps fritté orienté; une couche d'électrolyte solide constituée d'un matériau conducteur d'ions lithium; une couche d'électrode négative contenant du lithium; et un collecteur d'électrode positive, qui est une feuille métallique ayant une épaisseur de 5 à 30 µm et qui est en contact de surface totale avec la surface de la plaque d'électrode positive orientée sur le côté opposé à la couche d'électrolyte solide dans un état non adhésif dépourvu d'adhésif. Cette plaque d'électrode positive orientée comprend une pluralité de grains cristallins composés d'un oxyde composite de lithium dans lequel le corps fritté orienté a une structure stratifiée de sel gemme, la pluralité de grains cristallins ayant le plan (003) orienté parallèlement à la surface de plaque de la plaque d'électrode positive orientée.
PCT/JP2017/026286 2016-08-02 2017-07-20 Pile au lithium tout solide WO2018025649A1 (fr)

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US10903500B2 (en) * 2018-10-10 2021-01-26 Panasonic Intellectual Property Management Co., Ltd. Battery and cell stack
WO2021124945A1 (fr) * 2019-12-19 2021-06-24 日本電気硝子株式会社 Élément pour dispositifs de stockage d'électricité, et dispositif de stockage d'électricité
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WO2023080216A1 (fr) * 2021-11-04 2023-05-11 大日本印刷株式会社 Film isolant, batterie tout solide, et procédé de fabrication de batterie tout solide
EP4002513A4 (fr) * 2019-07-18 2024-02-14 Murata Manufacturing Co., Ltd. Batterie à électrolyte solide
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GB2601794A (en) * 2020-12-10 2022-06-15 Dyson Technology Ltd Electrode structure and method of making an electrode structure
WO2022209172A1 (fr) * 2021-03-31 2022-10-06 パナソニックＩｐマネジメント株式会社 Électrode pour batterie secondaire, batterie secondaire et procédé de fabrication d'électrode pour batterie secondaire
WO2023080216A1 (fr) * 2021-11-04 2023-05-11 大日本印刷株式会社 Film isolant, batterie tout solide, et procédé de fabrication de batterie tout solide

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