WO2022080404A1 - Solid-state battery - Google Patents

Solid-state battery Download PDF

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Publication number
WO2022080404A1
WO2022080404A1 PCT/JP2021/037860 JP2021037860W WO2022080404A1 WO 2022080404 A1 WO2022080404 A1 WO 2022080404A1 JP 2021037860 W JP2021037860 W JP 2021037860W WO 2022080404 A1 WO2022080404 A1 WO 2022080404A1
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Prior art keywords
electrode layer
solid
state battery
layer
external electrode
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PCT/JP2021/037860
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French (fr)
Japanese (ja)
Inventor
修 近川
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株式会社村田製作所
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Publication of WO2022080404A1 publication Critical patent/WO2022080404A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M10/058—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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/54—Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/547—Terminals characterised by the disposition of the terminals on the cells
    • H01M50/548—Terminals characterised by the disposition of the terminals on the cells on opposite sides of the cell
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • 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 a solid-state battery.
  • Secondary batteries that can be repeatedly charged and discharged have been used for various purposes.
  • a secondary battery is used as a power source for electronic devices such as smartphones and notebook computers.
  • the conventional solid-state battery 500' has a battery element 100'with a positive electrode layer 10A' facing each other, a negative electrode layer 10B', and a solid electrolyte layer 20' intervening between the positive electrode layer 10A'and the negative electrode layer 10B'. And an external electrode 200'provided on the surface of the battery element 100'(see FIGS. 8 and 9).
  • the inventor of the present application has newly found that the conventional solid-state battery 500'may have the following technical problems.
  • the interface region 300'between the battery element 100'and the external electrode 200' has a substantially planar shape in a cross-sectional view of the battery. That is, the substantially planar end faces of the battery element 100'and the substantially planar end faces of the external electrode 200' are merely in opposite contact with each other.
  • the electrode layer 10'of the positive electrode layer 10A'and the negative electrode layer 10B' has at least an electrode material layer of a non-metal material such as an oxide material as a main constituent member.
  • the external electrode 200'provided on the surface of the battery element 100' is made of a metal material.
  • the constituent material of the electrode material layer as the main constituent member of the electrode layer 10'and the constituent material of the external electrode 200' can be different from each other. Due to the difference in the materials, the degree of integral sintering of the electrode layer 10'and the external electrode 200' is not sufficient.
  • the substantially planar end faces of the battery element 100'and the substantially planar end faces of the external electrode 200' are in facing contact with each other, and (ii) the degree of integral sintering of the electrode layer 10'and the external electrode 200'.
  • the degree of interconnection between the electrode layer 10'and the external electrode 200' is not strong, and it may be difficult to maintain the interconnection.
  • stress is applied to the interconnected portion due to the expansion and contraction of the electrode layer 10'during charging and discharging, so that the interconnection between the two may not be maintained. ..
  • a main object of the present invention is to provide a solid-state battery capable of suitably maintaining the interconnection between the electrode layer and the external electrode.
  • a battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer, and a battery element. Equipped with an external electrode provided on the surface of the battery element, A solid-state battery is provided in which a fitting portion in which at least one of the positive electrode layer and the negative electrode layer and the external electrode are fitted to each other is formed in an interface region between the battery element and the external electrode.
  • the interconnection between the electrode layer and the external electrode can be suitably maintained.
  • FIG. 1 is a sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • FIG. 2 is an enlarged cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • FIG. 3 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 4 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 5 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 6 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 1 is a sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • FIG. 2 is an enlarged cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • FIG. 3 is a sectional view schematic
  • FIG. 7 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 8 is a cross-sectional view schematically showing a conventional solid-state battery.
  • FIG. 9 is an enlarged cross-sectional view schematically showing a conventional solid-state battery.
  • solid-state battery refers to a battery whose constituent elements are composed of solids in a broad sense, and in a narrow sense, all the constituent elements (particularly all constituent elements) are composed of solids.
  • the solid-state battery of the present invention is a laminated solid-state battery in which the layers forming the battery building unit are laminated to each other, and preferably such layers are made of a sintered body.
  • the "solid-state battery” as used herein can include not only a secondary battery that can be repeatedly charged and discharged, but also a primary battery that can only be discharged.
  • the solid-state battery is a secondary battery.
  • the "secondary battery” is not overly bound by its name and may include, for example, a power storage device.
  • the "cross-sectional view” as used herein is a state when the solid-state battery is viewed from a direction substantially perpendicular to the thickness direction based on the stacking direction of the material layers constituting the solid-state battery.
  • the "vertical direction” and “horizontal direction” used directly or indirectly in the present specification correspond to the vertical direction and the horizontal direction in the figure, respectively. Unless otherwise specified, the same sign or symbol shall indicate the same member / part or the same meaning. In one preferred embodiment, it can be considered that the vertical downward direction (that is, the direction in which gravity acts) corresponds to the "downward direction” and the opposite direction corresponds to the "upward direction”.
  • the solid-state battery has at least an electrode layer of a positive electrode / a negative electrode and a solid electrolyte.
  • the solid-state battery includes a battery element (corresponding to a solid-state battery laminate) including a battery constituent unit composed of a positive electrode layer, a negative electrode layer, and a solid electrolyte interposed therein at least.
  • each layer constituting the solid-state battery may be formed by firing, and the positive electrode layer, the negative electrode layer, the solid electrolyte, and the like may form the firing layer.
  • the positive electrode layer, the negative electrode layer and the solid electrolyte are integrally fired with each other, and therefore the battery elements (corresponding to the solid-state battery laminate) form an integrally fired body.
  • the positive electrode layer is an electrode layer containing at least a positive electrode active material.
  • the positive electrode layer may further contain a solid electrolyte.
  • the positive electrode layer is composed of a calcined body containing at least positive electrode active material particles and solid electrolyte particles.
  • the negative electrode layer is an electrode layer containing at least a negative electrode active material.
  • the negative electrode layer may further contain a solid electrolyte.
  • the negative electrode layer is composed of a sintered body containing at least negative electrode active material particles and solid electrolyte particles.
  • the positive electrode active material and the negative electrode active material are substances involved in the transfer of electrons in a solid-state battery. Ions move (conduct) between the positive electrode layer and the negative electrode layer via the solid electrolyte, and electrons are transferred to charge and discharge. It is particularly preferable that each of the electrode layers of the positive electrode layer and the negative electrode layer is a layer capable of occluding and releasing lithium ions or sodium ions. That is, the solid-state battery is preferably an all-solid-state secondary battery in which lithium ions or sodium ions move between the positive electrode layer and the negative electrode layer via the solid electrolyte to charge and discharge the battery.
  • Examples of the positive electrode active material contained in the positive electrode layer include a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing layered oxide, and lithium having a spinel-type structure. At least one selected from the group consisting of oxides and the like can be mentioned.
  • Examples of lithium-containing phosphoric acid compounds having a pear-con type structure include Li 3 V 2 (PO 4 ) 3 .
  • Examples of lithium-containing phosphoric acid compounds having an olivine-type structure include Li 3 Fe 2 (PO 4 ) 3 , LiFePO 4 , and / or LiMnPO 4 .
  • lithium-containing layered oxides examples include LiCoO 2 and / or LiCo 1/3 Ni 1/3 Mn 1/3 O 2 and the like.
  • lithium-containing oxides having a spinel-type structure examples include LiMn 2 O 4 and / or LiNi 0.5 Mn 1.5 O 4 and the like.
  • the type of the lithium compound is not particularly limited, and may be, for example, a lithium transition metal composite oxide and a lithium transition metal phosphoric acid compound.
  • the lithium transition metal composite oxide is a general term for oxides containing lithium and one or more kinds of transition metal elements as constituent elements, and the lithium transition metal phosphoric acid compound is one or more kinds with lithium. It is a general term for phosphoric acid compounds containing the transition metal element of.
  • the type of the transition metal element is not particularly limited, and is, for example, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), and the like.
  • a sodium-containing phosphoric acid compound having a nacicon-type structure a sodium-containing phosphoric acid compound having an olivine-type structure, a sodium-containing layered oxide, and sodium having a spinel-type structure are contained.
  • At least one selected from the group consisting of oxides and the like can be mentioned.
  • sodium-containing phosphoric acid compounds Na 3 V 2 (PO 4 ) 3 , NaCoFe 2 (PO 4 ) 3 , Na 2 Ni 2 Fe (PO 4 ) 3 , Na 3 Fe 2 (PO 4 ) 3 , Na. 2 FeP 2 O 7 , Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ), and at least one selected from the group consisting of NaFeO 2 as a sodium-containing layered oxide.
  • the positive electrode active material may be, for example, an oxide, a disulfide, a chalcogenide, a conductive polymer, or the like.
  • the oxide may be, for example, titanium oxide, vanadium oxide, manganese dioxide, or the like.
  • the disulfide is, for example, titanium disulfide or molybdenum sulfide.
  • the chalcogenide may be, for example, niobium selenate or the like.
  • the conductive polymer may be, for example, disulfide, polypyrrole, polyaniline, polythiophene, polyparastyrene, polyacetylene, polyacene and the like.
  • Examples of the negative electrode active material contained in the negative electrode layer include oxides containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb and Mo, carbon materials such as graphite, and graphite-lithium. At least one selected from the group consisting of compounds, lithium alloys, lithium-containing phosphoric acid compounds having a pearcon-type structure, lithium-containing phosphoric acid compounds having an olivine-type structure, lithium-containing oxides having a spinel-type structure, and the like. Be done. Examples of lithium alloys include Li-Al and the like.
  • lithium-containing phosphoric acid compounds having a pear-con type structure examples include Li 3 V 2 (PO 4 ) 3 and / or LiTi 2 (PO 4 ) 3 .
  • lithium-containing phosphoric acid compounds having an olivine-type structure examples include Li 3 Fe 2 (PO 4 ) 3 and / or LiCuPO 4 .
  • lithium-containing oxides having a spinel-type structure include Li 4 Ti 5 O 12 .
  • the negative electrode active material capable of absorbing and releasing sodium ions includes a sodium-containing phosphoric acid compound having a nacicon-type structure, a sodium-containing phosphoric acid compound having an olivine-type structure, a sodium-containing oxide having a spinel-type structure, and the like. There is at least one selected from the group consisting of.
  • the positive electrode layer and the negative electrode layer may be made of the same material.
  • the positive electrode layer and / or the negative electrode layer may contain a conductive material.
  • the conductive material contained in the positive electrode layer and the negative electrode layer include at least one metal material such as silver, palladium, gold, platinum, aluminum, copper and nickel, and carbon.
  • the positive electrode layer and / or the negative electrode layer may contain a sintering aid.
  • a sintering aid at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide and phosphorus oxide can be mentioned.
  • the thicknesses of the positive electrode layer and the negative electrode layer are not particularly limited, but may be, for example, 2 ⁇ m or more and 50 ⁇ m or less, particularly 5 ⁇ m or more and 30 ⁇ m or less, respectively.
  • the positive electrode layer and the negative electrode layer may include a positive electrode current collector layer and a negative electrode current collector layer, respectively.
  • the positive electrode current collector layer and the negative electrode current collector layer may each have the form of a foil.
  • the positive electrode current collector layer and the negative electrode current collector layer are in the form of a fired body, respectively. May have.
  • the positive electrode current collector constituting the positive electrode current collector layer and the negative electrode current collector constituting the negative electrode current collector it is preferable to use a material having a high conductivity, for example, silver, palladium, gold, platinum, aluminum, copper. , And / or nickel and the like may be used.
  • Each of the positive electrode current collector and the negative electrode current collector may have an electrical connection portion for electrically connecting to the outside, and may be configured to be electrically connectable to the external electrode.
  • the positive electrode current collector layer and the negative electrode current collector layer have the form of a fired body, they may be composed of a fired body containing a conductive material and a sintering aid.
  • the conductive material contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the conductive material that can be contained in the positive electrode layer and the negative electrode layer.
  • the sintering aid contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the sintering aid that can be contained in the positive electrode layer and the negative electrode layer.
  • the positive electrode collector layer and the negative electrode current collector layer are not essential in the solid-state battery, and a solid-state battery in which such a positive electrode current collector layer and the negative electrode current collector layer are not provided is also conceivable. That is, the solid-state battery included in the package of the present invention may be a solid-state battery without a current collector layer.
  • the solid electrolyte is a material capable of conducting lithium ions or sodium ions.
  • the solid electrolyte that forms a battery constituent unit in a solid-state battery may form a layer in which lithium ions can be conducted between the positive electrode layer and the negative electrode layer.
  • Specific examples of the solid electrolyte include a lithium-containing phosphoric acid compound having a pearcon structure, an oxide having a perovskite structure, an oxide having a garnet type or a garnet type similar structure, and an oxide glass ceramics-based lithium ion conductor. Can be mentioned.
  • Li x My (PO 4 ) 3 (1 ⁇ x ⁇ 2, 1 ⁇ y ⁇ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected).
  • Examples of the lithium-containing phosphoric acid compound having a pear-con structure include Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 .
  • Examples of oxides having a perovskite structure include La 0.55 Li 0.35 TiO 3 and the like.
  • Li 7 La 3 Zr 2 O 12 and the like can be mentioned.
  • oxide glass ceramics-based lithium ion conductor for example, a phosphoric acid compound (LATP) containing lithium, aluminum and titanium as a constituent element, and a phosphoric acid compound (LAGP) containing lithium, aluminum and germanium as constituent elements are used. Can be done.
  • LATP phosphoric acid compound
  • LAGP phosphoric acid compound
  • Examples of the solid electrolyte in which sodium ions can be conducted include sodium-containing phosphoric acid compounds having a nacicon structure, oxides having a perovskite structure, oxides having a garnet type or a garnet type similar structure, and the like.
  • sodium-containing phosphoric acid compound having a pearcon structure Na x My (PO 4 ) 3 (1 ⁇ x ⁇ 2, 1 ⁇ y ⁇ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected).
  • the solid electrolyte may contain a sintering aid.
  • the sintering aid contained in the solid electrolyte may be selected from, for example, the same materials as the sintering aid that can be contained in the positive electrode layer and the negative electrode layer.
  • the thickness of the solid electrolyte is not particularly limited.
  • the thickness of the solid electrolyte layer located between the positive electrode layer and the negative electrode layer may be, for example, 1 ⁇ m or more and 15 ⁇ m or less, particularly 1 ⁇ m or more and 5 ⁇ m or less.
  • the solid-state battery is generally provided with an external electrode.
  • an external electrode is provided on the side of the solid-state battery.
  • an external electrode on the positive electrode side connected to the positive electrode layer and an external electrode on the negative electrode side connected to the negative electrode layer are provided on the side portion of the solid-state battery.
  • the external electrode on the positive electrode layer side is joined to an end portion of the positive electrode layer, specifically, a drawer portion formed at the end portion of the positive electrode layer.
  • the external electrode on the negative electrode layer side is joined to an end portion of the negative electrode layer, specifically, a drawer portion formed at the end portion of the negative electrode layer.
  • the external electrode preferably comprises glass or glass ceramics from the viewpoint of joining to the extraction portion of the electrode layer.
  • the external electrode preferably contains a material having a high conductivity.
  • the specific material of the external electrode is not particularly limited, but may include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin and nickel.
  • the exterior can generally be formed on the outermost side of the solid state battery and is intended for electrical, physical and / or chemical protection.
  • the material constituting the exterior is preferably excellent in insulation, durability and / or moisture resistance, and is environmentally safe.
  • the exterior is a layer that covers the surface of the battery element so that the drawer portion of each electrode layer and each external electrode can be joined. Specifically, the exterior covers the surface of the battery element so that the drawer portion of the positive electrode layer and the external electrode on the positive electrode side can be bonded, and the extraction portion of the negative electrode layer and the external electrode on the negative electrode side can be bonded to the battery element. Cover the surface of the. That is, the exterior does not cover the entire surface of the battery element without gaps, but the drawer portion of the electrode layer (the end portion of the electrode layer) is exposed in order to join the drawer portion of the electrode layer of the battery element and the external electrode. Cover the battery elements as such.
  • the inventor of the present application has diligently studied a solution for making it possible to suitably maintain the interconnection between the electrode layer and the external electrode.
  • the inventor of the present application has come up with the present invention based on the following technical idea.
  • the electrode layer and the external electrode are brought into contact with each other, instead of bringing the electrode layer, which is a component of the battery element, and the external electrode provided on the surface of the battery element into end face contact as in the conventional case. It is based on the technical idea of fitting.
  • the “interface region between the battery element and the external electrode” as used herein refers to a boundary region where the battery element and the external electrode are in contact with each other.
  • the “fitting portion” as used herein refers to a portion in which the electrode layer and the external electrode are fitted to each other in a broad sense, and in a narrow sense, an end portion of the electrode layer, that is, one side of a drawer portion and an external electrode. Refers to the part where the main surface of the is fitted to each other. It should be noted that the “fitting portion” is not limited to a mode in which one of the electrode layer and the external electrode have a convex shape and the other has a concave shape as long as the electrode layer and the external electrode fit each other. I will add it.
  • the term “electrode layer” as used herein is a general term for a positive electrode layer and a negative electrode layer, and is used when the positive electrode layer and the negative electrode layer are not particularly distinguished.
  • FIG. 1 is a sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • FIG. 2 is an enlarged cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
  • the solid-state battery 500 includes a positive electrode layer 10A, a negative electrode layer 10B, and a battery element 20 having a solid electrolyte layer 20 interposed between the positive electrode layer 10A and the negative electrode layer 10B. Consists of having 100.
  • the battery element 100 includes at least one battery building unit including the positive electrode layer 10A, the negative electrode layer 10B, and the solid electrolyte layer 20 along the stacking direction.
  • the positive electrode layer 10A includes at least a positive electrode material layer (which may also be referred to as a positive electrode active material layer or a positive electrode mixture layer), and the negative electrode layer 10B includes at least a negative electrode material layer (which may also be referred to as a negative electrode active material layer or a negative electrode mixture layer).
  • the electrode layer 10 does not necessarily have to have a current collector layer.
  • the electrode layer 10 includes a body portion extending in a direction different from the stacking direction, for example, a substantially vertical direction, and an end portion extending in the stacking direction.
  • the end portion includes an end portion (corresponding to a drawer portion) 10a on the external electrode connection side and an end portion on the external electrode non-connection side.
  • the electrode material layer contained in the electrode layer 10 contains a non-metal material such as an oxide material.
  • the external electrode 200 is made of a metal material. That is, the constituent material of the electrode material layer included in the electrode layer 10 and the constituent material of the external electrode 200 may be different from each other.
  • one embodiment of the present invention is based on the technical idea of fitting the electrode layer 10 and the external electrode 200, which are the constituent elements of the battery element 100, to each other.
  • a fitting portion in which the electrode layer 10 and the external electrode 200 are fitted to each other is formed in the interface region 300 between the battery element 100 and the external electrode 200.
  • the fact that the fitting portion is formed means that one of the electrode layer 10 and the external electrode 200 is provided so as to be partially inserted into the other of the electrode layer 10 and the external electrode 200.
  • the fact that the fitting portion is formed means that one of the electrode layer 10 and the external electrode 200 is partially surrounded by the other of the electrode layer 10 and the external electrode 200 in the interface region 300. It means that it is.
  • the substantially planar end face of the battery element including the electrode layer and the substantially planar end face of the external electrode are in opposite contact with each other. Focusing on the electrode layer, the electrode layer also has a substantially planar end face. Therefore, between the electrode layer and the external electrode, the end faces having a substantially planar shape are merely in opposition contact with each other. Further, the difference between the constituent material of the electrode material layer contained in the electrode layer 10 and the constituent material of the external electrode 200 may lead to the difficulty of integral sintering of the electrode layer 10 and the external electrode 200.
  • the end faces having a substantially planar shape of both face each other as before.
  • the end faces of the electrode layer and the external electrode having a substantially planar shape are merely opposed to each other. Therefore, for example, the electrode layer (specifically, the drawer portion of the electrode layer) and the external electrode are fitted to each other.
  • the electrode layer specifically, the drawer portion of the electrode layer
  • the external electrode are fitted to each other.
  • a fitting portion in which the two are fitted together is formed in the “part where integral sintering is not easy between the electrode layer 10 and the external electrode 200”, such fitting results in the fitting.
  • the contact area between the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 and the external electrode 200 can be relatively increased.
  • This provides a so-called “anchor effect”, which can improve the degree of interconnection between the electrode layer 10 and the external electrode 200. That is, this combined portion can function as an anchor effect providing portion.
  • a thermal shock is applied to the fitting portion or the solid-state battery 500 is repeatedly charged and discharged, it is possible to suitably maintain the interconnection between the two.
  • the contact resistance can be made smaller than that of the conventional solid-state battery, thereby increasing the internal resistance of the solid-state battery 500. Can be made smaller. From the above, it is possible to suitably charge and discharge the solid-state battery 500 as a whole. That is, improvement in the characteristics of the solid-state battery according to the embodiment of the present invention can be expected.
  • the electrode layer 10 can have a convex end (corresponding to a drawer), and the external electrode 200 can locally have a concave portion.
  • the electrode layer 10 can have a convex end (corresponding to a drawer), and the external electrode 200 can locally have a concave portion.
  • FIGS. 1 and 2 such a form will be described as an example (see FIGS. 1 and 2).
  • the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 has a convex portion shape.
  • the end surface of the external electrode 200 locally has a concave shape into which the end portion 10a of the electrode layer 10 having the convex shape can be fitted.
  • the end portion 10a of the convex portion-shaped electrode layer 10 is configured to be inserted into the concave portion-shaped portion of the external electrode 200 at the fitting portion.
  • the concave portion of the external electrode 200 mateably receives the end portion 10a of the convex electrode layer 10.
  • the end portion 10a of the convex portion-shaped electrode layer 10 can be inserted into the concave portion-shaped portion of the external electrode 200.
  • the end portion 10a of the electrode layer 10 has an outer curved surface in a cross-sectional view of the battery.
  • the fitting surface itself between the end portion 10a of the electrode layer 10 and the recess of the external electrode 200 has a fine uneven shape (corresponding to a jagged shape).
  • the present invention is not limited to this, and from the viewpoint of realizing fitting, at least a part of the convex portion-shaped end portion of the electrode layer 10 may be positioned in the concave portion portion of the external electrode 200.
  • the degree of insertion of the convex end portion of the electrode layer 10 into the external electrode 200 is fitted from the viewpoint of both suitable fitting of the two and prevention of protrusion of the electrode layer 10 from the outer surface of the external electrode 200. It is preferably 5% or more and 70% or less, 10% or more and 60% or less, and 20% or more and 50% or less, for example, about 50% of the thickness of the external electrode 200 in the portion where the joint portion is not formed.
  • the cross-sectional shape of the interface region between the battery element and the external electrode is a substantially planar shape as a whole.
  • the interface region 300 is composed of a substantially planar main interface region 301 and a non-planar sub-interface region continuous with the main portion 301. It will be configured. That is, it can be said that the shape of the interface region 300 is a combination of a substantially planar shape and a non-planar shape as compared with the conventional solid-state battery.
  • the interface region 300 composed of a combination of a substantially planar shape and a non-planar shape
  • the following aspects can be adopted.
  • an embodiment in which the non-planar sub-interface region itself is composed of only the region 302 forming the fitting portion can be adopted.
  • the region 302 is positioned outside the main interface region 301 having a substantially planar shape.
  • FIG. 3 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 4 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • the non-planar sub-interface region is a region 302I having an outwardly curved shape forming a fitting portion, and a region 302I continuous with the region 302I and opposite to the region 302I. It is possible to take an embodiment composed of the region 303I having a shape curved in the direction. In this case, the outer curved region 302I is positioned inside the substantially planar main interface region 301I.
  • the region 303I having a shape curved in the opposite direction is not itself an interface region forming a fitting portion between the electrode layer 10I and the external electrode 200I.
  • the region 303I is an interface region forming a portion where the convex external electrode 200I locally and the concave portion of the corresponding solid electrolyte 20I are fitted.
  • FIG. 5 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • FIG. 6 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • the interface region 300II between the battery element 100II and the external electrode 200II can have a slope morphology.
  • the interface region 300II is composed of a main interface region 301II having a slope and a substantially planar shape and a sub-interface region having a non-planar shape continuous with the main portion 301II.
  • the non-planar sub-interface region itself is composed of only the region 302II forming the fitting portion, and the region 302II is positioned outside the sloped and substantially planar main interface region 301.
  • the embodiments shown in FIGS. 5 and 6 are more preferable than the embodiments shown in FIG. 1 in the following points.
  • the main interface region 301 extends in the substantially vertical direction and has a substantially planar shape.
  • the main interface region 301II has a slope and a substantially planar shape.
  • an increase in the area size of the fitting portion means an increase in the contact area between the end portion 10aII of the electrode layer 10II and the external electrode 200II.
  • the contact resistance can be made smaller as compared with the embodiment shown in FIG. 1, and the internal resistance of the solid-state battery 500II can also be made smaller. From the above, it is possible to suitably charge and discharge the solid-state battery 500II as a whole.
  • the fitting portion where the end portion (corresponding to the drawer portion) of the electrode layer and the external electrode are fitted to each other is at a predetermined interval. It is preferable that two or more of them are formed (see FIGS. 1, 3 and 5). It was
  • the single fitting portion has been focused on according to the embodiments shown in FIGS. 1, 3 and 5.
  • the technical effect that can be achieved by the fitting portions is more preferable. Can be played.
  • the contact resistance can be made smaller by increasing the number of portions where the contact area between the end of the electrode layer and the external electrode increases, so that the internal resistance of the solid-state battery can also be made smaller. Therefore, it becomes possible to more preferably charge and discharge the solid-state battery as a whole.
  • FIG. 7 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
  • the electrode layer and the external electrode are fitted to each other in the "fitting portion" formed by the end portion (corresponding to the drawer portion) of the electrode layer and the external electrode.
  • the relationship is not limited to a mode in which one of the two has a convex shape and the other has a concave shape.
  • the embodiment shown in FIGS. 1 to 6 is based on an embodiment in which the electrode layer has a convex shape and the external electrode has a concave shape.
  • the embodiment shown in FIGS. 1 to 6 is only an example for forming the fitting portion, and as shown in FIG. 7, the external electrode has a convex shape and the electrode layer has a concave shape. It can also be based on aspects.
  • the electrode layer 10III may have a concave end portion 10aIII (corresponding to a drawer portion), and the external electrode 200III may locally have a convex end surface.
  • the convex portion-shaped portion of the external electrode 200III is locally inserted into the end portion 10aIII of the concave-shaped electrode layer 10III.
  • the concave electrode layer 10III mateably accepts the convex portion of the external electrode 20033.
  • a fitting portion in which both are fitted is formed in the "part where integral sintering is not easy between the electrode layer 10III and the external electrode 200III". Therefore, such fitting can relatively increase the contact area between the end portion 10aIII (corresponding to the drawer portion) of the electrode layer 10III and the external electrode 200III as compared with the conventional solid-state battery. This provides a so-called “anchor effect” and can improve the degree of interconnection between the electrode layer 10III and the external electrode 200III.
  • the solid-state battery according to the embodiment of the present invention can be manufactured by a printing method such as a screen printing method, a green sheet method using a green sheet, or a composite method thereof.
  • Step of forming unfired laminate First, on each base material (for example, PET film), a paste for a solid electrolyte layer, a paste for a positive electrode material layer, a paste for a positive electrode current collector layer, a paste for a negative electrode material layer, a paste for a negative electrode current collector layer, and a paste for an insulating portion. , And the protective layer paste is applied.
  • base material for example, PET film
  • Each paste uses a predetermined constituent material of each layer appropriately selected from the group consisting of a positive electrode active material, a negative electrode active material, a conductive material, a solid electrolyte material, an insulating material, and a sintering aid, and an organic material as a solvent. It can be produced by wet mixing with a dissolved organic vehicle.
  • the paste for the positive electrode material layer includes, for example, a positive electrode active material, a conductive material, a solid electrolyte material, an organic material and a solvent.
  • the paste for the negative electrode material layer includes, for example, a negative electrode active material, a conductive material, a solid electrolyte material, an organic material and a solvent.
  • the paste for the positive electrode current collector layer / the paste for the negative electrode current collector layer at least one may be selected from the group consisting of, for example, silver, palladium, gold, platinum, aluminum, copper, and nickel.
  • the paste for the solid electrolyte layer includes, for example, a solid electrolyte material, a sintering aid, an organic material and a solvent.
  • Protective layer pastes include, for example, insulating material materials, organic materials and solvents. Insulating pastes include, for example, insulating material materials, organic materials and solvents.
  • Media can be used in wet mixing, and specifically, a ball mill method, a viscomill method, or the like can be used. On the other hand, a wet mixing method that does not use a medium may be used, and a sand mill method, a high-pressure homogenizer method, a kneader dispersion method, or the like can be used.
  • a paste for a predetermined solid electrolyte layer can be prepared by wet-mixing a predetermined solid electrolyte material, a sintering aid, and an organic vehicle in which an organic material is dissolved in a solvent.
  • the solid electrolyte material include a lithium-containing phosphoric acid compound having a pearcon structure, an oxide having a perovskite structure, an oxide having a garnet type or a garnet type similar structure, and the like.
  • the lithium-containing phosphoric acid compound having a pear-con structure Li x My (PO 4 ) 3 (1 ⁇ x ⁇ 2, 1 ⁇ y ⁇ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected).
  • Examples of the lithium-containing phosphoric acid compound having a pear-con structure include Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 .
  • Examples of oxides having a perovskite structure include La 0.55 Li 0.35 TiO 3 and the like.
  • As an example of an oxide having a garnet type or a garnet type-like structure Li 7 La 3 Zr 2 O 12 and the like can be mentioned.
  • Examples of the positive electrode active material contained in the positive electrode material layer paste include a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing layered oxide, and a spinel-type structure. At least one is selected from the group consisting of lithium-containing oxides and the like.
  • the insulating material contained in the paste for the insulating portion may be composed of, for example, a glass material, a ceramic material, or the like.
  • the insulating material material contained in the protective layer paste for example, it is preferable to use at least one selected from the group consisting of glass materials, ceramic materials, thermosetting resin materials, photocurable resin materials and the like.
  • the organic material contained in the paste is not particularly limited, but at least one polymer material selected from the group consisting of polyvinyl acetal resin, cellulose resin, polyacrylic resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin and the like can be used. Can be used.
  • the solvent is not particularly limited as long as it can dissolve the organic material, and for example, toluene and / or ethanol can be used.
  • Examples of the negative electrode active material contained in the paste for the negative electrode material layer include an oxide containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo, and graphite-lithium. It is selected from at least one group consisting of a compound, a lithium alloy, a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing oxide having a spinel-type structure, and the like.
  • the sintering aid may be at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, and silicon oxide.
  • the coated paste is dried on a hot plate heated to 30 to 50 ° C. to form a solid electrolyte layer sheet, a positive electrode layer sheet, and a negative electrode layer sheet having a predetermined thickness on a substrate (for example, PET film), respectively.
  • a substrate for example, PET film
  • a solid electrolyte sheet or an insulating sheet is provided in the side region of the electrode sheet by screen printing.
  • a solid electrolyte portion sheet or an insulating portion sheet is provided so as to surround the external electrode non-connecting portion excluding the portion of the side portion of the electrode sheet to which the external electrode is connected later.
  • thermocompression bonding at a predetermined pressure (for example, about 50 to about 100 MPa) and subsequent isotropic pressure pressing at a predetermined pressure (for example, about 150 to about 300 MPa). From the above, a predetermined laminated body can be formed.
  • the end face of the laminated body is pressed against a predetermined mold.
  • the end portion (specifically, the end portion on the external electrode connection side) of the portion to be the electrode layer can be exposed from the end surface (corresponding to the side surface) of the laminated body.
  • a predetermined laminate in which the end of the portion to be the electrode layer is exposed is subjected to firing.
  • the firing is carried out by heating at, for example, 600 ° C. to 1000 ° C. in a nitrogen gas atmosphere.
  • the laminated body may be further subjected to an individualization step if necessary.
  • the exposure of the end of the electrode layer is not limited to the method of pressing the end face of the laminated body against a predetermined mold.
  • an external electrode is attached to the side surface of the laminate having the electrode layer with the exposed end.
  • an external electrode is attached to the side surface of the laminate (corresponding to a battery element) so as to cover the end of the exposed electrode layer.
  • External electrodes are provided so as to be electrically connectable to the positive electrode layer and the negative electrode layer, respectively.
  • the external electrode is preferably composed of at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel. Further, it is preferable to provide a protective layer to the extent that the external electrode is not covered by sputtering, spray coating or the like.
  • the solid-state battery 500 according to the embodiment of the present invention can be suitably manufactured (see FIG. 1).
  • a fitting portion in which both are fitted is formed at "a portion where integral sintering is not easy between the electrode layer 10 and the external electrode 200".
  • the contact area between the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 and the external electrode 200 can be relatively increased as compared with the conventional solid-state battery.
  • This provides a so-called “anchor effect”, which can improve the degree of interconnection between the electrode layer 10 and the external electrode 200.
  • anchor effect which can improve the degree of interconnection between the electrode layer 10 and the external electrode 200.
  • the solid-state battery according to the embodiment of the present invention can be used in various fields where storage is expected. Although only an example, the solid-state battery according to the embodiment of the present invention is used in the fields of electricity, information, and communication (for example, mobile phones, smartphones, smart watches, laptop computers, digital cameras, activities, etc.) in which mobile devices and the like are used.
  • the solid-state battery according to the embodiment of the present invention is used in the fields of electricity, information, and communication (for example, mobile phones, smartphones, smart watches, laptop computers, digital cameras, activities, etc.) in which mobile devices and the like are used.
  • Mobile device fields such as scales, arm computers, and electronic paper), home / small industrial applications (eg, power tools, golf carts, home / nursing / industrial robot fields), large industrial applications (eg, forklifts, etc.) Elevators, Gulf Cranes), Transportation Systems (eg, Hybrid Vehicles, Electric Vehicles, Buses, Trains, Electric Assisted Bicycles, Electric motorcycles, etc.), Power Systems Applications (eg, Power Generation, Road Conditioners, Smart Grids) , General household installation type power storage system, etc.), medical use (medical equipment field such as earphone hearing aid), pharmaceutical use (dose management system, etc.), IoT field, space / deep sea use (for example, space exploration) It can be used in fields such as aircraft and submersible research vessels).
  • home / small industrial applications eg, power tools, golf carts, home / nursing / industrial robot fields
  • large industrial applications eg, forklifts, etc.
  • Elevators Gulf Cranes
  • Transportation Systems eg,

Abstract

In one embodiment of the present invention, a solid-state battery is provided. The solid-state battery is characterized by comprising: a battery element provided with a positive-electrode layer, a negative-electrode layer, and a solid electrolyte layer interposed between the positive-electrode layer and the negative-electrode layer; and an external electrode provided on the surface of the battery element, a fitting portion in which the positive-electrode layer and/or the negative-electrode layer is fitted to the external electrode being formed in the interface region between the battery element and the external electrode.

Description

固体電池Solid state battery
　本発明は、固体電池に関する。 The present invention relates to a solid-state battery.
　従前より充放電が繰り返し可能な二次電池が様々な用途に用いられている。例えば、二次電池は、スマートフォン、ノートパソコン等の電子機器の電源として用いられている。 Secondary batteries that can be repeatedly charged and discharged have been used for various purposes. For example, a secondary battery is used as a power source for electronic devices such as smartphones and notebook computers.
　当該二次電池においてはイオンを移動させるための媒体として有機溶媒等の液体の電解質（電解液）が従来より使用されている。しかしながら、電解液を用いた二次電池においては、電解液の漏液等の問題がある。そのため、液体の電解質に代えて固体電解質を有して成る固体電池の開発が進められている。 In the secondary battery, a liquid electrolyte (electrolyte solution) such as an organic solvent has been conventionally used as a medium for moving ions. However, in the secondary battery using the electrolytic solution, there is a problem such as leakage of the electrolytic solution. Therefore, the development of a solid-state battery having a solid electrolyte instead of the liquid electrolyte is underway.
特開２０１５－２２０１０４号公報JP-A-2015-220104
　従前の固体電池５００’は、相互に対向する正極層１０Ａ’、負極層１０Ｂ’、および正極層１０Ａ’と負極層１０Ｂ’との間に介在する固体電解質層２０’を備えた電池要素１００’と、電池要素１００’の表面に設けられた外部電極２００’とを備える（図８および図９参照）。 The conventional solid-state battery 500'has a battery element 100'with a positive electrode layer 10A' facing each other, a negative electrode layer 10B', and a solid electrolyte layer 20' intervening between the positive electrode layer 10A'and the negative electrode layer 10B'. And an external electrode 200'provided on the surface of the battery element 100'(see FIGS. 8 and 9).
　ここで、本願発明者は、従前の固体電池５００’では以下の技術的課題があり得ることを新たに見出した。第１に、従前の固体電池５００’では、電池の断面視で、電池要素１００’と外部電極２００’との界面領域３００’は略平面形状となっている。即ち、電池要素１００’の略平面形状の端面と外部電極２００’の略平面形状の端面同士が対向接触しているにすぎない。第２に、正極層１０Ａ’と負極層１０Ｂ’の電極層１０’はメイン構成部材として酸化物材等の非金属材の電極材層を少なくとも有して成る。一方、電池要素１００’の表面に設けられる外部電極２００’は金属材から構成される。即ち、電極層１０’のメイン構成部材としての電極材層と外部電極２００’の構成材料が互いに相違し得る。かかる材料の相違により、電極層１０’と外部電極２００’との一体焼結の程度が十分ではない。 Here, the inventor of the present application has newly found that the conventional solid-state battery 500'may have the following technical problems. First, in the conventional solid-state battery 500', the interface region 300'between the battery element 100'and the external electrode 200' has a substantially planar shape in a cross-sectional view of the battery. That is, the substantially planar end faces of the battery element 100'and the substantially planar end faces of the external electrode 200' are merely in opposite contact with each other. Second, the electrode layer 10'of the positive electrode layer 10A'and the negative electrode layer 10B' has at least an electrode material layer of a non-metal material such as an oxide material as a main constituent member. On the other hand, the external electrode 200'provided on the surface of the battery element 100' is made of a metal material. That is, the constituent material of the electrode material layer as the main constituent member of the electrode layer 10'and the constituent material of the external electrode 200'can be different from each other. Due to the difference in the materials, the degree of integral sintering of the electrode layer 10'and the external electrode 200' is not sufficient.
　（ｉ）電池要素１００’の略平面形状の端面と外部電極２００’の略平面形状の端面同士が対向接触し、かつ（ｉｉ）電極層１０’と外部電極２００’との一体焼結の程度が十分ではないという状況下では、電極層１０’と外部電極２００’との間の相互接続の程度が強くなく、その相互接続を維持することが困難となる虞がある。特に、固体電池５００’を充放電させると、充放電時に電極層１０’が膨張収縮することに起因して、応力がこの相互接続部分にかかるため、両者の相互接続の維持ができない虞がある。その結果として、固体電池５００’の充放電を好適に実施することが困難となり得る。 (I) The substantially planar end faces of the battery element 100'and the substantially planar end faces of the external electrode 200' are in facing contact with each other, and (ii) the degree of integral sintering of the electrode layer 10'and the external electrode 200'. However, the degree of interconnection between the electrode layer 10'and the external electrode 200' is not strong, and it may be difficult to maintain the interconnection. In particular, when the solid-state battery 500'is charged and discharged, stress is applied to the interconnected portion due to the expansion and contraction of the electrode layer 10'during charging and discharging, so that the interconnection between the two may not be maintained. .. As a result, it may be difficult to suitably charge and discharge the solid-state battery 500'.
　本発明はかかる事情に鑑みて為されたものである。即ち、本発明の主たる目的は、電極層と外部電極との間の相互接続を好適に維持可能な固体電池を提供することである。 The present invention was made in view of such circumstances. That is, a main object of the present invention is to provide a solid-state battery capable of suitably maintaining the interconnection between the electrode layer and the external electrode.
　上記目的を達成するために、本発明の一実施形態では、
　正極層、負極層、および該正極層と該負極層との間に介在する固体電解質層を備えた電池要素と、
　電池要素の表面に設けられた外部電極と
を備え、
　前記電池要素と前記外部電極との界面領域において、前記正極層と前記負極層の少なくとも一方の電極層と前記外部電極とが互いに嵌り合った嵌合部分が形成されている、固体電池が供される。 In order to achieve the above object, in one embodiment of the present invention,
A battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer, and a battery element.
Equipped with an external electrode provided on the surface of the battery element,
A solid-state battery is provided in which a fitting portion in which at least one of the positive electrode layer and the negative electrode layer and the external electrode are fitted to each other is formed in an interface region between the battery element and the external electrode. To.
　本発明の一実施形態によれば、電極層と外部電極との間の相互接続を好適に維持可能である。 According to one embodiment of the present invention, the interconnection between the electrode layer and the external electrode can be suitably maintained.
図１は、本発明の一実施形態に係る固体電池を模式的に示す断面図である。FIG. 1 is a sectional view schematically showing a solid-state battery according to an embodiment of the present invention. 図２は、本発明の一実施形態に係る固体電池を模式的に示す拡大断面図である。FIG. 2 is an enlarged cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention. 図３は、本発明の別実施形態に係る固体電池を模式的に示す断面図である。FIG. 3 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention. 図４は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。FIG. 4 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention. 図５は、本発明の別実施形態に係る固体電池を模式的に示す断面図である。FIG. 5 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention. 図６は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。FIG. 6 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention. 図７は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。FIG. 7 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention. 図８は、従前の固体電池を模式的に示す断面図である。FIG. 8 is a cross-sectional view schematically showing a conventional solid-state battery. 図９は、従前の固体電池を模式的に示す拡大断面図である。FIG. 9 is an enlarged cross-sectional view schematically showing a conventional solid-state battery.
　本発明の一実施形態に係る固体電池について説明する前に、固体電池の基本的構成について説明しておく。本明細書でいう「固体電池」とは、広義にはその構成要素が固体から構成されている電池を指し、狭義にはその構成要素（特に全ての構成要素）が固体から構成されている全固体電池を指す。ある好適な態様では、本発明の固体電池は、電池構成単位を成す各層が互いに積層するように構成された積層型固体電池であり、好ましくはそのような各層が焼結体から成っている。本明細書でいう「固体電池」は、充電および放電の繰り返しが可能な二次電池のみならず、放電のみが可能な一次電池をも包含し得る。本発明のある好適な態様では、固体電池は二次電池である。「二次電池」は、その名称に過度に拘泥されるものではなく、例えば、蓄電デバイスなども包含し得る。 Before explaining the solid-state battery according to the embodiment of the present invention, the basic configuration of the solid-state battery will be described. The term "solid-state battery" as used herein refers to a battery whose constituent elements are composed of solids in a broad sense, and in a narrow sense, all the constituent elements (particularly all constituent elements) are composed of solids. Refers to a solid-state battery. In one preferred embodiment, the solid-state battery of the present invention is a laminated solid-state battery in which the layers forming the battery building unit are laminated to each other, and preferably such layers are made of a sintered body. The "solid-state battery" as used herein can include not only a secondary battery that can be repeatedly charged and discharged, but also a primary battery that can only be discharged. In one preferred embodiment of the invention, the solid-state battery is a secondary battery. The "secondary battery" is not overly bound by its name and may include, for example, a power storage device.
　本明細書でいう「断面視」とは、固体電池を構成する材層の積層方向に基づく厚み方向に対して略垂直な方向から固体電池をみたときの状態のことである。本明細書で直接的または間接的に用いる“上下方向”および“左右方向”は、それぞれ図中における上下方向および左右方向に相当する。特記しない限り、同じ符号または記号は、同じ部材・部位または同じ意味内容を示すものとする。ある好適な態様では、鉛直方向下向き（すなわち、重力が働く方向）が「下方向」に相当し、その逆向きが「上方向」に相当すると捉えることができる。 The "cross-sectional view" as used herein is a state when the solid-state battery is viewed from a direction substantially perpendicular to the thickness direction based on the stacking direction of the material layers constituting the solid-state battery. The "vertical direction" and "horizontal direction" used directly or indirectly in the present specification correspond to the vertical direction and the horizontal direction in the figure, respectively. Unless otherwise specified, the same sign or symbol shall indicate the same member / part or the same meaning. In one preferred embodiment, it can be considered that the vertical downward direction (that is, the direction in which gravity acts) corresponds to the "downward direction" and the opposite direction corresponds to the "upward direction".
　本明細書で言及する各種の数値範囲は、特段の説明が付されない限り、下限および上限の数値そのものを含むことを意図している。つまり、例えば１～１０といった数値範囲を例にとれば、特段の説明の付記がない限り、下限値の“１”を含むと共に、上限値の“１０”をも含むものとして解釈され得る。 The various numerical ranges referred to herein are intended to include the lower and upper limits themselves, unless otherwise stated. That is, taking a numerical range such as 1 to 10 as an example, it can be interpreted as including the lower limit value "1" and the upper limit value "10" unless otherwise specified.
［固体電池の基本的構成］
　固体電池は、正極・負極の電極層と固体電解質とを少なくとも有して成る。具体的には固体電池は、正極層、負極層、およびそれらの間に少なくとも介在する固体電解質から成る電池構成単位を含んだ電池要素（固体電池積層体に相当）を有して成る。 [Basic configuration of solid-state battery]
The solid-state battery has at least an electrode layer of a positive electrode / a negative electrode and a solid electrolyte. Specifically, the solid-state battery includes a battery element (corresponding to a solid-state battery laminate) including a battery constituent unit composed of a positive electrode layer, a negative electrode layer, and a solid electrolyte interposed therein at least.
　固体電池は、それを構成する各層が焼成によって形成されていてもよく、正極層、負極層および固体電解質などが焼成層をなしていてもよい。好ましくは、正極層、負極層および固体電解質は、それぞれが互いに一体焼成されており、それゆえ電池要素（固体電池積層体に相当）が一体焼成体を成していることが好ましい。 In the solid-state battery, each layer constituting the solid-state battery may be formed by firing, and the positive electrode layer, the negative electrode layer, the solid electrolyte, and the like may form the firing layer. Preferably, the positive electrode layer, the negative electrode layer and the solid electrolyte are integrally fired with each other, and therefore the battery elements (corresponding to the solid-state battery laminate) form an integrally fired body.
　正極層は、少なくとも正極活物質を含んで成る電極層である。正極層は、更に固体電解質を含んで成っていてよい。ある好適な態様では、正極層は、正極活物質粒子と固体電解質粒子とを少なくとも含む焼成体から構成されている。一方、負極層は、少なくとも負極活物質を含んで成る電極層である。負極層は、更に固体電解質を含んで成っていてよい。ある好適な態様では、負極層は、負極活物質粒子と固体電解質粒子とを少なくとも含む焼結体から構成されている。 The positive electrode layer is an electrode layer containing at least a positive electrode active material. The positive electrode layer may further contain a solid electrolyte. In one preferred embodiment, the positive electrode layer is composed of a calcined body containing at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer is an electrode layer containing at least a negative electrode active material. The negative electrode layer may further contain a solid electrolyte. In one preferred embodiment, the negative electrode layer is composed of a sintered body containing at least negative electrode active material particles and solid electrolyte particles.
　正極活物質および負極活物質は、固体電池において電子の受け渡しに関与する物質である。固体電解質を介してイオンは正極層と負極層との間で移動（伝導）して電子の受け渡しが行われることで充放電がなされる。正極層および負極層の各電極層は特にリチウムイオンまたはナトリウムイオンを吸蔵放出可能な層であることが好ましい。つまり、固体電池は、固体電解質を介してリチウムイオンまたはナトリウムイオンが正極層と負極層との間で移動して電池の充放電が行われる全固体型二次電池であることが好ましい。 The positive electrode active material and the negative electrode active material are substances involved in the transfer of electrons in a solid-state battery. Ions move (conduct) between the positive electrode layer and the negative electrode layer via the solid electrolyte, and electrons are transferred to charge and discharge. It is particularly preferable that each of the electrode layers of the positive electrode layer and the negative electrode layer is a layer capable of occluding and releasing lithium ions or sodium ions. That is, the solid-state battery is preferably an all-solid-state secondary battery in which lithium ions or sodium ions move between the positive electrode layer and the negative electrode layer via the solid electrolyte to charge and discharge the battery.
（正極活物質）
　正極層に含まれる正極活物質としては、例えば、ナシコン型構造を有するリチウム含有リン酸化合物、オリビン型構造を有するリチウム含有リン酸化合物、リチウム含有層状酸化物、および、スピネル型構造を有するリチウム含有酸化物等から成る群から選択される少なくとも一種が挙げられる。ナシコン型構造を有するリチウム含有リン酸化合物の一例としては、Ｌｉ3Ｖ2（ＰＯ4）3等が挙げられる。オリビン型構造を有するリチウム含有リン酸化合物の一例としては、Ｌｉ3Ｆｅ2（ＰＯ4）3、ＬｉＦｅＰＯ4、および／またはＬｉＭｎＰＯ4等が挙げられる。リチウム含有層状酸化物の一例としては、ＬｉＣｏＯ2、および／またはＬｉＣｏ1/3Ｎｉ1/3Ｍｎ1/3Ｏ2等が挙げられる。スピネル型構造を有するリチウム含有酸化物の一例としては、ＬｉＭｎ2Ｏ4、および／またはＬｉＮｉ0.5Ｍｎ1.5Ｏ4等が挙げられる。リチウム化合物の種類は、特に限定されないが、例えば、リチウム遷移金属複合酸化物およびリチウム遷移金属リン酸化合物としてよい。リチウム遷移金属複合酸化物は、リチウムと１種類または２種類以上の遷移金属元素とを構成元素として含む酸化物の総称であると共に、リチウム遷移金属リン酸化合物は、リチウムと１種類または２種類以上の遷移金属元素とを構成元素として含むリン酸化合物の総称である。遷移金属元素の種類は、特に限定されないが、例えば、コバルト（Ｃｏ）、ニッケル（Ｎｉ）、マンガン（Ｍｎ）および鉄（Ｆｅ）などである。 (Positive electrode active material)
Examples of the positive electrode active material contained in the positive electrode layer include a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing layered oxide, and lithium having a spinel-type structure. At least one selected from the group consisting of oxides and the like can be mentioned. Examples of lithium-containing phosphoric acid compounds having a pear-con type structure include Li 3 V 2 (PO 4 ) 3 . Examples of lithium-containing phosphoric acid compounds having an olivine-type structure include Li 3 Fe 2 (PO 4 ) 3 , LiFePO 4 , and / or LiMnPO 4 . Examples of lithium-containing layered oxides include LiCoO 2 and / or LiCo 1/3 Ni 1/3 Mn 1/3 O 2 and the like. Examples of lithium-containing oxides having a spinel-type structure include LiMn 2 O 4 and / or LiNi 0.5 Mn 1.5 O 4 and the like. The type of the lithium compound is not particularly limited, and may be, for example, a lithium transition metal composite oxide and a lithium transition metal phosphoric acid compound. The lithium transition metal composite oxide is a general term for oxides containing lithium and one or more kinds of transition metal elements as constituent elements, and the lithium transition metal phosphoric acid compound is one or more kinds with lithium. It is a general term for phosphoric acid compounds containing the transition metal element of. The type of the transition metal element is not particularly limited, and is, for example, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), and the like.
　また、ナトリウムイオンを吸蔵放出可能な正極活物質としては、ナシコン型構造を有するナトリウム含有リン酸化合物、オリビン型構造を有するナトリウム含有リン酸化合物、ナトリウム含有層状酸化物およびスピネル型構造を有するナトリウム含有酸化物等から成る群から選択される少なくとも１種が挙げられる。例えば、ナトリウム含有リン酸化合物の場合、Ｎａ3Ｖ2（ＰＯ4）3、ＮａＣｏＦｅ2（ＰＯ4）3、Ｎａ2Ｎｉ2Ｆｅ（ＰＯ4）3、Ｎａ3Ｆｅ2（ＰＯ4）3、Ｎａ2ＦｅＰ2Ｏ7、Ｎａ4Ｆｅ3（ＰＯ4）2（Ｐ2Ｏ7）、およびナトリウム含有層状酸化物としてＮａＦｅＯ2から成る群から選択される少なくとも一種が挙げられる。 In addition, as the positive electrode active material capable of absorbing and releasing sodium ions, a sodium-containing phosphoric acid compound having a nacicon-type structure, a sodium-containing phosphoric acid compound having an olivine-type structure, a sodium-containing layered oxide, and sodium having a spinel-type structure are contained. At least one selected from the group consisting of oxides and the like can be mentioned. For example, in the case of sodium-containing phosphoric acid compounds, Na 3 V 2 (PO 4 ) 3 , NaCoFe 2 (PO 4 ) 3 , Na 2 Ni 2 Fe (PO 4 ) 3 , Na 3 Fe 2 (PO 4 ) 3 , Na. 2 FeP 2 O 7 , Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ), and at least one selected from the group consisting of NaFeO 2 as a sodium-containing layered oxide.
　この他、正極活物質は、例えば、酸化物、二硫化物、カルコゲン化物または導電性高分子等でもよい。酸化物は、例えば、酸化チタン、酸化バナジウムまたは二酸化マンガン等でもよい。二硫化物は、例えば、二硫化チタンまたは硫化モリブデン等である。カルコゲン化物は、例えば、セレン化ニオブ等でもよい。導電性高分子は、例えば、ジスルフィド、ポリピロール、ポリアニリン、ポリチオフェン、ポリパラスチレン、ポリアセチレンまたはポリアセン等でもよい。 In addition, the positive electrode active material may be, for example, an oxide, a disulfide, a chalcogenide, a conductive polymer, or the like. The oxide may be, for example, titanium oxide, vanadium oxide, manganese dioxide, or the like. The disulfide is, for example, titanium disulfide or molybdenum sulfide. The chalcogenide may be, for example, niobium selenate or the like. The conductive polymer may be, for example, disulfide, polypyrrole, polyaniline, polythiophene, polyparastyrene, polyacetylene, polyacene and the like.
（負極活物質）
　負極層に含まれる負極活物質としては、例えば、Ｔｉ、Ｓｉ、Ｓｎ、Ｃｒ、Ｆｅ、ＮｂおよびＭｏから成る群より選ばれる少なくとも一種の元素を含む酸化物、黒鉛などの炭素材料、黒鉛－リチウム化合物、リチウム合金、ナシコン型構造を有するリチウム含有リン酸化合物、オリビン型構造を有するリチウム含有リン酸化合物、ならびに、スピネル型構造を有するリチウム含有酸化物等から成る群から選択される少なくとも一種が挙げられる。リチウム合金の一例としては、Ｌｉ－Ａｌ等が挙げられる。ナシコン型構造を有するリチウム含有リン酸化合物の一例としては、Ｌｉ3Ｖ2（ＰＯ4）3、および／またはＬｉＴｉ2（ＰＯ4）3等が挙げられる。オリビン型構造を有するリチウム含有リン酸化合物の一例としては、Ｌｉ3Ｆｅ2（ＰＯ4）3、および／またはＬｉＣｕＰＯ4等が挙げられる。スピネル型構造を有するリチウム含有酸化物の一例としては、Ｌｉ4Ｔｉ5Ｏ12等が挙げられる。 (Negative electrode active material)
Examples of the negative electrode active material contained in the negative electrode layer include oxides containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb and Mo, carbon materials such as graphite, and graphite-lithium. At least one selected from the group consisting of compounds, lithium alloys, lithium-containing phosphoric acid compounds having a pearcon-type structure, lithium-containing phosphoric acid compounds having an olivine-type structure, lithium-containing oxides having a spinel-type structure, and the like. Be done. Examples of lithium alloys include Li-Al and the like. Examples of lithium-containing phosphoric acid compounds having a pear-con type structure include Li 3 V 2 (PO 4 ) 3 and / or LiTi 2 (PO 4 ) 3 . Examples of lithium-containing phosphoric acid compounds having an olivine-type structure include Li 3 Fe 2 (PO 4 ) 3 and / or LiCuPO 4 . Examples of lithium-containing oxides having a spinel-type structure include Li 4 Ti 5 O 12 .
　また、ナトリウムイオンを吸蔵放出可能な負極活物質としては、ナシコン型構造を有するナトリウム含有リン酸化合物、オリビン型構造を有するナトリウム含有リン酸化合物、および、スピネル型構造を有するナトリウム含有酸化物等から成る群から選択される少なくとも１種が挙げられる。 The negative electrode active material capable of absorbing and releasing sodium ions includes a sodium-containing phosphoric acid compound having a nacicon-type structure, a sodium-containing phosphoric acid compound having an olivine-type structure, a sodium-containing oxide having a spinel-type structure, and the like. There is at least one selected from the group consisting of.
　なお、固体電池において、正極層と負極層とが同一材料から成っていてもよい。 In the solid-state battery, the positive electrode layer and the negative electrode layer may be made of the same material.
　正極層および／または負極層は、導電性材料を含んでいてもよい。正極層および負極層に含まれる導電性材料として、銀、パラジウム、金、プラチナ、アルミニウム、銅およびニッケル等の金属材料、ならびに炭素などから成る少なくとも１種を挙げることができる。 The positive electrode layer and / or the negative electrode layer may contain a conductive material. Examples of the conductive material contained in the positive electrode layer and the negative electrode layer include at least one metal material such as silver, palladium, gold, platinum, aluminum, copper and nickel, and carbon.
　さらに、正極層および／または負極層は、焼結助剤を含んでいてもよい。焼結助剤としては、リチウム酸化物、ナトリウム酸化物、カリウム酸化物、酸化ホウ素、酸化ケイ素、酸化ビスマスおよび酸化リンから成る群から選択される少なくとも１種を挙げることができる。 Further, the positive electrode layer and / or the negative electrode layer may contain a sintering aid. As the sintering aid, at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide and phosphorus oxide can be mentioned.
　正極層および負極層の厚みは特に限定されないが、例えば、それぞれ独立して２μｍ以上５０μｍ以下、特に５μｍ以上３０μｍ以下であってよい。 The thicknesses of the positive electrode layer and the negative electrode layer are not particularly limited, but may be, for example, 2 μm or more and 50 μm or less, particularly 5 μm or more and 30 μm or less, respectively.
（正極集電層／負極集電層）
　電極層の必須要素ではないものの、正極層および負極層は、それぞれ正極集電層および負極集電層を備えていてもよい。正極集電層および負極集電層はそれぞれ箔の形態を有していてもよい。しかしながら、一体焼成による電子伝導性向上、固体電池の製造コスト低減および／または固体電池の内部抵抗低減などの観点をより重視するならば、正極集電層および負極集電層はそれぞれ焼成体の形態を有していてもよい。正極集電層を構成する正極集電体および負極集電体を構成する負極集電体としては、導電率が大きい材料を用いることが好ましく、例えば、銀、パラジウム、金、プラチナ、アルミニウム、銅、および／またはニッケルなどを用いてよい。正極集電体および負極集電体はそれぞれ、外部と電気的に接続するための電気接続部を有してよく、外部電極と電気的に接続可能に構成されていてよい。なお、正極集電層および負極集電層が焼成体の形態を有する場合、それらは導電性材料および焼結助剤を含む焼成体により構成されてもよい。正極集電層および負極集電層に含まれる導電性材料は、例えば、正極層および負極層に含まれ得る導電性材料と同様の材料から選択されてよい。正極集電層および負極集電層に含まれる焼結助剤は、例えば、正極層・負極層に含まれ得る焼結助剤と同様の材料から選択されてよい。上述したように、固体電池において、正極集電層および負極集電層が必須というわけではなく、そのような正極集電層および負極集電層が設けられていない固体電池も考えられる。つまり、本発明のパッケージに含まれる固体電池は、集電層レスの固体電池であってもよい。 (Positive current collector layer / Negative electrode current collector layer)
Although not an essential element of the electrode layer, the positive electrode layer and the negative electrode layer may include a positive electrode current collector layer and a negative electrode current collector layer, respectively. The positive electrode current collector layer and the negative electrode current collector layer may each have the form of a foil. However, if more emphasis is placed on improving electron conductivity by integral firing, reducing the manufacturing cost of the solid-state battery, and / or reducing the internal resistance of the solid-state battery, the positive electrode current collector layer and the negative electrode current collector layer are in the form of a fired body, respectively. May have. As the positive electrode current collector constituting the positive electrode current collector layer and the negative electrode current collector constituting the negative electrode current collector, it is preferable to use a material having a high conductivity, for example, silver, palladium, gold, platinum, aluminum, copper. , And / or nickel and the like may be used. Each of the positive electrode current collector and the negative electrode current collector may have an electrical connection portion for electrically connecting to the outside, and may be configured to be electrically connectable to the external electrode. When the positive electrode current collector layer and the negative electrode current collector layer have the form of a fired body, they may be composed of a fired body containing a conductive material and a sintering aid. The conductive material contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the conductive material that can be contained in the positive electrode layer and the negative electrode layer. The sintering aid contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the sintering aid that can be contained in the positive electrode layer and the negative electrode layer. As described above, the positive electrode collector layer and the negative electrode current collector layer are not essential in the solid-state battery, and a solid-state battery in which such a positive electrode current collector layer and the negative electrode current collector layer are not provided is also conceivable. That is, the solid-state battery included in the package of the present invention may be a solid-state battery without a current collector layer.
（固体電解質）
　固体電解質は、リチウムイオンまたはナトリウムイオンが伝導可能な材質である。特に固体電池で電池構成単位を成す固体電解質は、正極層と負極層との間においてリチウムイオンが伝導可能な層を成していてよい。具体的な固体電解質としては、例えば、ナシコン構造を有するリチウム含有リン酸化合物、ペロブスカイト構造を有する酸化物、ガーネット型またはガーネット型類似構造を有する酸化物、酸化物ガラスセラミックス系リチウムイオン伝導体等が挙げられる。ナシコン構造を有するリチウム含有リン酸化合物としては、ＬｉxＭy（ＰＯ4）3（１≦ｘ≦２、１≦ｙ≦２、Ｍは、Ｔｉ、Ｇｅ、Ａｌ、ＧａおよびＺｒから成る群より選ばれた少なくとも一種）が挙げられる。ナシコン構造を有するリチウム含有リン酸化合物の一例としては、例えば、Ｌｉ1.2Ａｌ0.2Ｔｉ1.8（ＰＯ4）3等が挙げられる。ペロブスカイト構造を有する酸化物の一例としては、Ｌａ0.55Ｌｉ0.35ＴｉＯ3等が挙げられる。ガーネット型またはガーネット型類似構造を有する酸化物の一例としては、Ｌｉ7Ｌａ3Ｚｒ2Ｏ12等が挙げられる。酸化物ガラスセラミックス系リチウムイオン伝導体としては、例えば、リチウム、アルミニウムおよびチタンを構成元素に含むリン酸化合物（ＬＡＴＰ）、リチウム、アルミニウムおよびゲルマニウムを構成元素に含むリン酸化合物（ＬＡＧＰ）を用いることができる。 (Solid electrolyte)
The solid electrolyte is a material capable of conducting lithium ions or sodium ions. In particular, the solid electrolyte that forms a battery constituent unit in a solid-state battery may form a layer in which lithium ions can be conducted between the positive electrode layer and the negative electrode layer. Specific examples of the solid electrolyte include a lithium-containing phosphoric acid compound having a pearcon structure, an oxide having a perovskite structure, an oxide having a garnet type or a garnet type similar structure, and an oxide glass ceramics-based lithium ion conductor. Can be mentioned. As the lithium-containing phosphoric acid compound having a pear-con structure, Li x My (PO 4 ) 3 (1 ≦ x ≦ 2, 1 ≦ y ≦ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected). Examples of the lithium-containing phosphoric acid compound having a pear-con structure include Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 . Examples of oxides having a perovskite structure include La 0.55 Li 0.35 TiO 3 and the like. As an example of an oxide having a garnet type or a garnet type-like structure, Li 7 La 3 Zr 2 O 12 and the like can be mentioned. As the oxide glass ceramics-based lithium ion conductor, for example, a phosphoric acid compound (LATP) containing lithium, aluminum and titanium as a constituent element, and a phosphoric acid compound (LAGP) containing lithium, aluminum and germanium as constituent elements are used. Can be done.
　また、ナトリウムイオンが伝導可能な固体電解質としては、例えば、ナシコン構造を有するナトリウム含有リン酸化合物、ペロブスカイト構造を有する酸化物、ガーネット型またはガーネット型類似構造を有する酸化物等が挙げられる。ナシコン構造を有するナトリウム含有リン酸化合物としては、ＮａxＭy（ＰＯ4）3（１≦ｘ≦２、１≦ｙ≦２、Ｍは、Ｔｉ、Ｇｅ、Ａｌ、ＧａおよびＺｒから成る群より選ばれた少なくとも一種）が挙げられる。 Examples of the solid electrolyte in which sodium ions can be conducted include sodium-containing phosphoric acid compounds having a nacicon structure, oxides having a perovskite structure, oxides having a garnet type or a garnet type similar structure, and the like. As the sodium-containing phosphoric acid compound having a pearcon structure, Na x My (PO 4 ) 3 (1 ≦ x ≦ 2, 1 ≦ y ≦ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected).
　固体電解質は、焼結助剤を含んでいてもよい。固体電解質に含まれる焼結助剤は、例えば、正極層・負極層に含まれ得る焼結助剤と同様の材料から選択されてよい。 The solid electrolyte may contain a sintering aid. The sintering aid contained in the solid electrolyte may be selected from, for example, the same materials as the sintering aid that can be contained in the positive electrode layer and the negative electrode layer.
　固体電解質の厚みは特に限定されない。正極層と負極層との間に位置する固体電解質層の厚みは、例えば１μｍ以上１５μｍ以下、特に１μｍ以上５μｍ以下であってよい。 The thickness of the solid electrolyte is not particularly limited. The thickness of the solid electrolyte layer located between the positive electrode layer and the negative electrode layer may be, for example, 1 μm or more and 15 μm or less, particularly 1 μm or more and 5 μm or less.
（外部電極）
　固体電池には、一般に外部電極が設けられている。特に、固体電池の側部に外部電極が設けられている。具体的には、正極層と接続された正極側の外部電極と、負極層と接続された負極側の外部電極とが固体電池の側部に設けられている。正極層側の外部電極は、正極層の端部、具体的には正極層端部に形成された引出し部と接合されている。又、負極層側の外部電極は、負極層の端部、具体的には負極層端部に形成された引出し部と接合されている。好ましい１つの態様では、外部電極は、電極層の引出し部と接合させる観点から、ガラスまたはガラスセラミックスを含んでなることが好ましい。又、外部電極は、導電率が大きい材料を含んで成ることが好ましい。外部電極の具体的な材質としては、特に制限されるわけではないが、銀、金、プラチナ、アルミニウム、銅、スズおよびニッケルから成る群から選択される少なくとも一種を挙げることができる。 (External electrode)
The solid-state battery is generally provided with an external electrode. In particular, an external electrode is provided on the side of the solid-state battery. Specifically, an external electrode on the positive electrode side connected to the positive electrode layer and an external electrode on the negative electrode side connected to the negative electrode layer are provided on the side portion of the solid-state battery. The external electrode on the positive electrode layer side is joined to an end portion of the positive electrode layer, specifically, a drawer portion formed at the end portion of the positive electrode layer. Further, the external electrode on the negative electrode layer side is joined to an end portion of the negative electrode layer, specifically, a drawer portion formed at the end portion of the negative electrode layer. In one preferred embodiment, the external electrode preferably comprises glass or glass ceramics from the viewpoint of joining to the extraction portion of the electrode layer. Further, the external electrode preferably contains a material having a high conductivity. The specific material of the external electrode is not particularly limited, but may include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin and nickel.
（外装）
　外装は、一般に固体電池の最外側に形成され得るもので、電気的、物理的および／または化学的に保護するためのものである。外装を構成する材料としては絶縁性、耐久性および／または耐湿性に優れ、環境的に安全であることが好ましい。 (Exterior)
The exterior can generally be formed on the outermost side of the solid state battery and is intended for electrical, physical and / or chemical protection. The material constituting the exterior is preferably excellent in insulation, durability and / or moisture resistance, and is environmentally safe.
　外装は、各電極層の引出し部と各外部電極とがそれぞれ接合可能に電池要素の表面を覆う層である。具体的には、外装は、正極層の引出し部と正極側の外部電極とが接合可能に電池要素の表面を覆うと共に、負極層の引出し部と負極側の外部電極とが接合可能に電池要素の表面を覆う。即ち、外装は、電池要素の全面を隙間なく覆うのではなく、電池要素の電極層の引出し部と外部電極とを接合させるために、電極層の引出し部（電極層の端部）が露出するように電池要素を覆う。 The exterior is a layer that covers the surface of the battery element so that the drawer portion of each electrode layer and each external electrode can be joined. Specifically, the exterior covers the surface of the battery element so that the drawer portion of the positive electrode layer and the external electrode on the positive electrode side can be bonded, and the extraction portion of the negative electrode layer and the external electrode on the negative electrode side can be bonded to the battery element. Cover the surface of the. That is, the exterior does not cover the entire surface of the battery element without gaps, but the drawer portion of the electrode layer (the end portion of the electrode layer) is exposed in order to join the drawer portion of the electrode layer of the battery element and the external electrode. Cover the battery elements as such.
［本発明の固体電池の特徴部分］
　固体電池の基本的構成を考慮した上で、以下、本発明の一実施形態に係る固体電池の特徴部分について説明する。 [Characteristic Part of Solid State Battery of the Present Invention]
After considering the basic configuration of the solid-state battery, the characteristic portion of the solid-state battery according to the embodiment of the present invention will be described below.
　本願発明者は、電極層と外部電極との間の相互接続を好適に維持可能とするための解決策について鋭意検討した。その結果、本願発明者は、下記の技術的思想に基づき本発明を案出するに至った。具体的には、本発明は、従来のように電池要素の構成要素である電極層と電池要素の表面に設けられた外部電極とを端面接触させるのではなく、電極層と外部電極とを互いに嵌合させるという技術的思想に基づいている。 The inventor of the present application has diligently studied a solution for making it possible to suitably maintain the interconnection between the electrode layer and the external electrode. As a result, the inventor of the present application has come up with the present invention based on the following technical idea. Specifically, in the present invention, the electrode layer and the external electrode are brought into contact with each other, instead of bringing the electrode layer, which is a component of the battery element, and the external electrode provided on the surface of the battery element into end face contact as in the conventional case. It is based on the technical idea of fitting.
　本明細書でいう「電池要素と外部電極の界面領域」とは、電池要素と外部電極とが相互に接する境界領域を指す。本明細書でいう「嵌合部分」とは、広義には電極層と外部電極とが相互に嵌り合う部分を指し、狭義には電極層の端部、即ち引出し部と外部電極の一方の側の主面とが相互に嵌り合う部分を指す。なお、「嵌合部分」については、電極層と外部電極とが互いに嵌り合う関係であれば、両者の一方が凸部形態を有し他方が凹部形態を有する態様に限定されないことを確認的に付言しておく。本明細書でいう「電極層」とは正極層と負極層の総括名称であり、正極層と負極層とを特に区別しない場合に用いるものである。 The "interface region between the battery element and the external electrode" as used herein refers to a boundary region where the battery element and the external electrode are in contact with each other. The "fitting portion" as used herein refers to a portion in which the electrode layer and the external electrode are fitted to each other in a broad sense, and in a narrow sense, an end portion of the electrode layer, that is, one side of a drawer portion and an external electrode. Refers to the part where the main surface of the is fitted to each other. It should be noted that the "fitting portion" is not limited to a mode in which one of the electrode layer and the external electrode have a convex shape and the other has a concave shape as long as the electrode layer and the external electrode fit each other. I will add it. The term "electrode layer" as used herein is a general term for a positive electrode layer and a negative electrode layer, and is used when the positive electrode layer and the negative electrode layer are not particularly distinguished.
　以下、図面を用いて、本発明の一実施形態に係る固体電池の特徴部分について具体的に説明する。 Hereinafter, the characteristic portion of the solid-state battery according to the embodiment of the present invention will be specifically described with reference to the drawings.
　図１は本発明の一実施形態に係る固体電池を模式的に示す断面図である。図２は、本発明の一実施形態に係る固体電池を模式的に示す拡大断面図である。 FIG. 1 is a sectional view schematically showing a solid-state battery according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention.
　図１に示すように、本発明の一実施形態に係る固体電池５００は、正極層１０Ａ、負極層１０Ｂ、および正極層１０Ａと負極層１０Ｂとの間に介在する固体電解質層２０を備える電池要素１００を有して成る。具体的には、電池要素１００は、正極層１０Ａ、負極層１０Ｂ、および固体電解質層２０を備える電池構成単位を積層方向に沿って少なくとも１つ有して成る。 As shown in FIG. 1, the solid-state battery 500 according to the embodiment of the present invention includes a positive electrode layer 10A, a negative electrode layer 10B, and a battery element 20 having a solid electrolyte layer 20 interposed between the positive electrode layer 10A and the negative electrode layer 10B. Consists of having 100. Specifically, the battery element 100 includes at least one battery building unit including the positive electrode layer 10A, the negative electrode layer 10B, and the solid electrolyte layer 20 along the stacking direction.
　正極層１０Ａは少なくとも正極材層（正極活物質層、正極合材層とも称し得る）を含み、負極層１０Ｂは少なくとも負極材層（負極活物質層、負極合材層とも称し得る）を含む。換言すれば、電極層１０（正極層１０Ａ／負極層１０Ｂ）は集電層を必ずしも有することを必須とはしない。電極層１０は、積層方向に対して異なる方向に、例えば略垂直方向に延在するボディ部および積層方向に延在する端部を備える。当該端部としては、外部電極接続側の端部（引出し部分に相当）１０ａと外部電極非接続側の端部とがある。 The positive electrode layer 10A includes at least a positive electrode material layer (which may also be referred to as a positive electrode active material layer or a positive electrode mixture layer), and the negative electrode layer 10B includes at least a negative electrode material layer (which may also be referred to as a negative electrode active material layer or a negative electrode mixture layer). In other words, the electrode layer 10 (positive electrode layer 10A / negative electrode layer 10B) does not necessarily have to have a current collector layer. The electrode layer 10 includes a body portion extending in a direction different from the stacking direction, for example, a substantially vertical direction, and an end portion extending in the stacking direction. The end portion includes an end portion (corresponding to a drawer portion) 10a on the external electrode connection side and an end portion on the external electrode non-connection side.
　又、電極層１０に少なくとも含まれる電極材層は酸化物材等の非金属材を含む。一方、外部電極２００は金属材から構成される。即ち、電極層１０に含まれる電極材層の構成材料と外部電極２００の構成材料は互いに相違し得る。 Further, at least the electrode material layer contained in the electrode layer 10 contains a non-metal material such as an oxide material. On the other hand, the external electrode 200 is made of a metal material. That is, the constituent material of the electrode material layer included in the electrode layer 10 and the constituent material of the external electrode 200 may be different from each other.
　かかる構成を前提として、上述のように、本発明の一実施形態は、電池要素１００の構成要素である電極層１０と外部電極２００とを互いに嵌合させるという技術的思想に基づいている。具体的には、本発明の一実施形態では、電池要素１００と外部電極２００との界面領域３００にて、電極層１０および外部電極２００とが互いに嵌り合った嵌合部分が形成されている。 As described above, on the premise of such a configuration, one embodiment of the present invention is based on the technical idea of fitting the electrode layer 10 and the external electrode 200, which are the constituent elements of the battery element 100, to each other. Specifically, in one embodiment of the present invention, a fitting portion in which the electrode layer 10 and the external electrode 200 are fitted to each other is formed in the interface region 300 between the battery element 100 and the external electrode 200.
　別の観点からいうと、嵌合部分が形成されているということは、電極層１０および外部電極２００の一方が電極層１０および外部電極２００の他方に部分的に差し込まれるように設けられていることを意味する。更に別の観点からいうと、嵌合部分が形成されているということは、界面領域３００にて、電極層１０および外部電極２００の一方が電極層１０および外部電極２００の他方により部分的に取り囲まれていることを意味する。 From another point of view, the fact that the fitting portion is formed means that one of the electrode layer 10 and the external electrode 200 is provided so as to be partially inserted into the other of the electrode layer 10 and the external electrode 200. Means that. From yet another point of view, the fact that the fitting portion is formed means that one of the electrode layer 10 and the external electrode 200 is partially surrounded by the other of the electrode layer 10 and the external electrode 200 in the interface region 300. It means that it is.
　従前の固体電池では、電極層を含む電池要素の略平面形状の端面と外部電極の略平面形状の端面同士が対向接触する構成が採られていた。電極層に着目した場合、電極層も略平面形状の端面を有する。そのため、電極層と外部電極との間では、略平面形状の端面同士が対向接触していたにすぎない。更に、電極層１０に少なくとも含まれる電極材層の構成材料と外部電極２００の構成材料の違いは電極層１０と外部電極２００との一体焼結が容易ではないことにつながり得る。 In the conventional solid-state battery, the substantially planar end face of the battery element including the electrode layer and the substantially planar end face of the external electrode are in opposite contact with each other. Focusing on the electrode layer, the electrode layer also has a substantially planar end face. Therefore, between the electrode layer and the external electrode, the end faces having a substantially planar shape are merely in opposition contact with each other. Further, the difference between the constituent material of the electrode material layer contained in the electrode layer 10 and the constituent material of the external electrode 200 may lead to the difficulty of integral sintering of the electrode layer 10 and the external electrode 200.
　これに対して、本発明の一実施形態は、『電極層１０と外部電極２００との間の一体焼結が容易ではない部分』において、従前のように両者の略平面形状の端面同士を対向接触させる形態を採るのではなく、両者が嵌り合った嵌合部分を形成する形態を採る点に技術的特徴がある。従前の形態では、電極層と外部電極の略平面形状の端面同士を対向接触させるにすぎないため、例えば電極層（具体的には電極層の引出し部）と外部電極とが相互に嵌り合うといった概念、電極層が外部電極に部分的に差し込まれるといった概念、更には電極層が電外部電極により部分的に取り囲まれるといった概念がそもそも存在しない。 On the other hand, in one embodiment of the present invention, in the "portion where integral sintering between the electrode layer 10 and the external electrode 200 is not easy", the end faces having a substantially planar shape of both face each other as before. There is a technical feature in that it does not adopt a form of contact, but adopts a form of forming a fitted portion in which the two are fitted together. In the conventional form, the end faces of the electrode layer and the external electrode having a substantially planar shape are merely opposed to each other. Therefore, for example, the electrode layer (specifically, the drawer portion of the electrode layer) and the external electrode are fitted to each other. There is no concept, the concept that the electrode layer is partially inserted into the external electrode, and the concept that the electrode layer is partially surrounded by the electrical external electrode.
　本発明の一実施形態では、『電極層１０と外部電極２００との間の一体焼結が容易ではない部分』にて両者が嵌り合った嵌合部分が形成されているため、かかる嵌合により、従前の固体電池と比べて、電極層１０の端部１０ａ（引出し部に相当）と外部電極２００との接触面積を相対的に増大させることができる。これにより、いわゆる“アンカー効果”が供され、それにより電極層１０と外部電極２００との間の相互接続の程度を向上させることができる。即ち、この篏合部分はアンカー効果提供部分として機能し得る。その結果、かかる嵌合部分に熱衝撃が加わったり、固体電池５００の充放電が繰り返し実施されたとしても、両者の相互接続を好適に維持することが可能となる。これに加えて、かかる電極層１０の端部１０ａと外部電極２００との接触面積の増大により、従前の固体電池と比べて接触抵抗も小さくすることができ、それにより固体電池５００の内部抵抗も小さくできる。以上の事からも、全体として固体電池５００の充放電を好適に実施することが可能となる。即ち、本発明の一実施形態に係る固体電池の特性の向上が期待できる。 In one embodiment of the present invention, since a fitting portion in which the two are fitted together is formed in the “part where integral sintering is not easy between the electrode layer 10 and the external electrode 200”, such fitting results in the fitting. Compared with the conventional solid-state battery, the contact area between the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 and the external electrode 200 can be relatively increased. This provides a so-called "anchor effect", which can improve the degree of interconnection between the electrode layer 10 and the external electrode 200. That is, this combined portion can function as an anchor effect providing portion. As a result, even if a thermal shock is applied to the fitting portion or the solid-state battery 500 is repeatedly charged and discharged, it is possible to suitably maintain the interconnection between the two. In addition to this, by increasing the contact area between the end portion 10a of the electrode layer 10 and the external electrode 200, the contact resistance can be made smaller than that of the conventional solid-state battery, thereby increasing the internal resistance of the solid-state battery 500. Can be made smaller. From the above, it is possible to suitably charge and discharge the solid-state battery 500 as a whole. That is, improvement in the characteristics of the solid-state battery according to the embodiment of the present invention can be expected.
　以下では、本発明の例示的な実施形態について説明する。 Hereinafter, exemplary embodiments of the present invention will be described.
　一例として、電極層１０が凸部形態の端部（引出し部に相当）を有し、外部電極２００が凹部形状部分を局所的に有することができる。以下では、かかる形態を例に採り説明する（図１および図２参照）。 As an example, the electrode layer 10 can have a convex end (corresponding to a drawer), and the external electrode 200 can locally have a concave portion. Hereinafter, such a form will be described as an example (see FIGS. 1 and 2).
　図１および図２に示すように、電極層１０の端部１０ａ（引出し部に相当）は凸部形態を有する。一方、外部電極２００の端面は当該凸部形態の電極層１０の端部１０ａが嵌合可能な凹部形態を局所的に有する。この場合、かかる嵌合部分にて、凸部形状の電極層１０の端部１０ａが外部電極２００の凹部形状部分に差し込まれるように構成されている。換言すれば、外部電極２００の凹部形状部分が凸部形状の電極層１０の端部１０ａを嵌合可能に受容している。 As shown in FIGS. 1 and 2, the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 has a convex portion shape. On the other hand, the end surface of the external electrode 200 locally has a concave shape into which the end portion 10a of the electrode layer 10 having the convex shape can be fitted. In this case, the end portion 10a of the convex portion-shaped electrode layer 10 is configured to be inserted into the concave portion-shaped portion of the external electrode 200 at the fitting portion. In other words, the concave portion of the external electrode 200 mateably receives the end portion 10a of the convex electrode layer 10.
　凸部形状の電極層１０の端部１０ａが外部電極２００の凹部形状部分に差し込み可能であれば、特に限定されない。嵌合を円滑に実現する観点から、電極層１０の端部１０ａは電池の断面視で外側湾曲面を有することが好ましい。又、嵌合を強化する観点から、電極層１０の端部１０ａと外部電極２００の凹部との嵌合面自体が微細な凹凸形状（ギザギザ形状に相当）を有することが好ましい。 There is no particular limitation as long as the end portion 10a of the convex portion-shaped electrode layer 10 can be inserted into the concave portion-shaped portion of the external electrode 200. From the viewpoint of smoothly realizing the fitting, it is preferable that the end portion 10a of the electrode layer 10 has an outer curved surface in a cross-sectional view of the battery. Further, from the viewpoint of strengthening the fitting, it is preferable that the fitting surface itself between the end portion 10a of the electrode layer 10 and the recess of the external electrode 200 has a fine uneven shape (corresponding to a jagged shape).
　更に、嵌合を強化する観点から、電極層１０の凸部形状の端部の全てが外部電極２００の凹部部分内に位置づけられていることが好ましい。ただし、これに限定されることなく、嵌合実現の観点からは、電極層１０の凸部形状の端部の少なくとも一部が外部電極２００の凹部部分内に位置づけられていればよい。外部電極２００内への電極層１０の凸部形状の端部の差込みの程度は、好適な両者の嵌合および外部電極２００の外表面からの電極層１０の突出し防止の両立の観点から、嵌合部分が形成されていない箇所の外部電極２００の厚さの５％以上７０％以下、１０％以上６０％以下、２０％以上５０％以下、例えば５０％程度であることが好ましい。 Further, from the viewpoint of strengthening the fitting, it is preferable that all the convex end portions of the electrode layer 10 are positioned in the concave portion portion of the external electrode 200. However, the present invention is not limited to this, and from the viewpoint of realizing fitting, at least a part of the convex portion-shaped end portion of the electrode layer 10 may be positioned in the concave portion portion of the external electrode 200. The degree of insertion of the convex end portion of the electrode layer 10 into the external electrode 200 is fitted from the viewpoint of both suitable fitting of the two and prevention of protrusion of the electrode layer 10 from the outer surface of the external electrode 200. It is preferably 5% or more and 70% or less, 10% or more and 60% or less, and 20% or more and 50% or less, for example, about 50% of the thickness of the external electrode 200 in the portion where the joint portion is not formed.
（界面領域の構成）
　電池要素と外部電極との間の界面領域の構成を全体的な視点でみると、以下のことが言える。具体的には、従前の固体電池では、電池要素と外部電極との界面領域の断面形状は全体として略平面形状となっている。これに対して、本発明の一実施形態では、嵌合部分の存在により、界面領域３００は、略平面形状のメイン界面領域３０１と当該メイン部分３０１に連続する非平面形状のサブ界面領域とから構成されることとなる。すなわち、従前の固体電池と比べると、界面領域３００の形状は略平面形状および非平面形状もの組合せからなっていると言える。 (Structure of interface area)
Looking at the configuration of the interface region between the battery element and the external electrode from an overall perspective, the following can be said. Specifically, in the conventional solid-state battery, the cross-sectional shape of the interface region between the battery element and the external electrode is a substantially planar shape as a whole. On the other hand, in one embodiment of the present invention, due to the presence of the fitting portion, the interface region 300 is composed of a substantially planar main interface region 301 and a non-planar sub-interface region continuous with the main portion 301. It will be configured. That is, it can be said that the shape of the interface region 300 is a combination of a substantially planar shape and a non-planar shape as compared with the conventional solid-state battery.
　略平面形状と非平面形状の組合せからなる界面領域３００としては、例えば以下の態様を採ることができる。一例としては、図１に示すように、非平面形状のサブ界面領域自体が嵌合部分を形作る領域３０２のみから構成される態様を採ることができる。この場合、当該領域３０２が略平面形状のメイン界面領域３０１よりも外側に位置づけられる。 As the interface region 300 composed of a combination of a substantially planar shape and a non-planar shape, for example, the following aspects can be adopted. As an example, as shown in FIG. 1, an embodiment in which the non-planar sub-interface region itself is composed of only the region 302 forming the fitting portion can be adopted. In this case, the region 302 is positioned outside the main interface region 301 having a substantially planar shape.
　図３は、本発明の別実施形態に係る固体電池を模式的に示す断面図である。図４は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。 FIG. 3 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
　別例としては、図３および図４に示すように、非平面形状のサブ界面領域が、嵌合部分を形作る外側方向に湾曲する形状の領域３０２Ｉと、これに連続しかつ領域３０２Ｉとは反対方向に湾曲する形状の領域３０３Ｉから構成される態様を採ることができる。この場合、外側湾曲形状の領域３０２Ｉが略平面形状のメイン界面領域３０１Ｉよりも内側に位置づけられる。 As another example, as shown in FIGS. 3 and 4, the non-planar sub-interface region is a region 302I having an outwardly curved shape forming a fitting portion, and a region 302I continuous with the region 302I and opposite to the region 302I. It is possible to take an embodiment composed of the region 303I having a shape curved in the direction. In this case, the outer curved region 302I is positioned inside the substantially planar main interface region 301I.
　図３および図４に示す態様は図１に示す態様よりも以下の点でより好ましい態様である。具体的には、反対方向に湾曲する形状の領域３０３Ｉはそれ自体電極層１０Ｉと外部電極２００Ｉの嵌合部分を形作る界面領域ではない。しかしながら、同領域３０３Ｉは局所的に凸部形状の外部電極２００Ｉとこれに対応する固体電解質２０Ｉの凹部形状部分とが嵌合する部分を形作る界面領域となる。 The embodiments shown in FIGS. 3 and 4 are more preferable than the embodiments shown in FIG. 1 in the following points. Specifically, the region 303I having a shape curved in the opposite direction is not itself an interface region forming a fitting portion between the electrode layer 10I and the external electrode 200I. However, the region 303I is an interface region forming a portion where the convex external electrode 200I locally and the concave portion of the corresponding solid electrolyte 20I are fitted.
　以上の事から、図３および図４に示す態様に従えば、単一の非平面形状のサブ界面領域に着目した場合、（１）電極層１０Ｉと外部電極２００Ｉとの嵌合部分と（２）外部電極２００Ｉと固体電解質２０Ｉとの嵌合部分、即ち少なくとも２つの嵌合部分が形成されることとなる。これにより、図１および図２に示す態様と比べて、『電極層１０Ｉと外部電極２００Ｉとの間の一体焼結が容易ではない部分』にて少なくとも２つの嵌合部分が形成されることとなる。これにより、いわゆる“アンカー効果”をより供され、電極層１０Ｉと外部電極２００Ｉとの間の相互接続の程度をより向上させることができる。その結果、両者の相互接続をより好適に維持することが可能となる。 From the above, according to the embodiments shown in FIGS. 3 and 4, when focusing on a single non-planar sub-interface region, (1) the fitting portion between the electrode layer 10I and the external electrode 200I and (2). ) A fitting portion between the external electrode 200I and the solid electrolyte 20I, that is, at least two fitting portions are formed. As a result, at least two fitting portions are formed in the "portion where integral sintering between the electrode layer 10I and the external electrode 200I is not easy" as compared with the embodiments shown in FIGS. 1 and 2. Become. As a result, the so-called "anchor effect" is further provided, and the degree of interconnection between the electrode layer 10I and the external electrode 200I can be further improved. As a result, it becomes possible to more preferably maintain the interconnection between the two.
　図５は、本発明の別実施形態に係る固体電池を模式的に示す断面図である。図６は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。 FIG. 5 is a sectional view schematically showing a solid-state battery according to another embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
　更なる別例としては、図５および図６に示すように、電池要素１００ＩＩと外部電極２００ＩＩとの間の界面領域３００ＩＩが斜面形態を有する態様を採ることができる。具体的には、界面領域３００ＩＩは、斜面かつ略平面形状のメイン界面領域３０１ＩＩと当該メイン部分３０１ＩＩに連続する非平面形状のサブ界面領域とから構成されることとなる。この場合、非平面形状のサブ界面領域自体が嵌合部分を形作る領域３０２ＩＩのみから構成され、当該領域３０２ＩＩが斜面かつ略平面形状のメイン界面領域３０１よりも外側に位置づけられる。 As a further alternative example, as shown in FIGS. 5 and 6, the interface region 300II between the battery element 100II and the external electrode 200II can have a slope morphology. Specifically, the interface region 300II is composed of a main interface region 301II having a slope and a substantially planar shape and a sub-interface region having a non-planar shape continuous with the main portion 301II. In this case, the non-planar sub-interface region itself is composed of only the region 302II forming the fitting portion, and the region 302II is positioned outside the sloped and substantially planar main interface region 301.
　図５および図６に示す態様は図１に示す態様よりも以下の点でより好ましい態様である。具体的には、図１に示す態様では、メイン界面領域３０１は略鉛直方向に延在しかつ略平面形状となっている。これに対して、図５および図６に示す態様では、メイン界面領域３０１ＩＩは斜面かつ略平面形状となっている。これにより、電極層１０ＩＩの大きさ、形状、および材料組成等が同一であるという前提下にて、電極層１０ＩＩの端部１０ａ（引出し部に相当）と外部電極２００ＩＩとの嵌合部分の領域サイズを大きくすることができる。 The embodiments shown in FIGS. 5 and 6 are more preferable than the embodiments shown in FIG. 1 in the following points. Specifically, in the embodiment shown in FIG. 1, the main interface region 301 extends in the substantially vertical direction and has a substantially planar shape. On the other hand, in the embodiment shown in FIGS. 5 and 6, the main interface region 301II has a slope and a substantially planar shape. As a result, on the premise that the size, shape, material composition, etc. of the electrode layer 10II are the same, the region of the fitting portion between the end portion 10a (corresponding to the drawer portion) of the electrode layer 10II and the external electrode 200II. You can increase the size.
　かかる嵌合部分の領域サイズの増大により、図１に示す態様と比べて、『電極層１０ＩＩと外部電極２００ＩＩとの間の一体焼結が容易ではない部分』にていわゆる“アンカー効果”をより供することができる。その結果、電極層１０ＩＩと外部電極２００ＩＩとの間の相互接続の程度をより向上させることができ、それによって両者の相互接続をより好適に維持することが可能となる。これに加えて、嵌合部分の領域サイズの増大は、電極層１０ＩＩの端部１０ａＩＩと外部電極２００ＩＩとの接触面積の増大を意味する。これにより、図１に示す態様と比べて接触抵抗もより小さくすることができ、それにより固体電池５００ＩＩの内部抵抗もより小さくできる。以上の事からも、全体として固体電池５００ＩＩの充放電を好適に実施することが可能となる。 Due to the increase in the area size of the fitting portion, the so-called "anchor effect" is further enhanced in the "part where integral sintering between the electrode layer 10II and the external electrode 200II is not easy" as compared with the embodiment shown in FIG. Can be served. As a result, the degree of interconnection between the electrode layer 10II and the external electrode 200II can be further improved, whereby the interconnection between the two can be more preferably maintained. In addition to this, an increase in the area size of the fitting portion means an increase in the contact area between the end portion 10aII of the electrode layer 10II and the external electrode 200II. As a result, the contact resistance can be made smaller as compared with the embodiment shown in FIG. 1, and the internal resistance of the solid-state battery 500II can also be made smaller. From the above, it is possible to suitably charge and discharge the solid-state battery 500II as a whole.
　更に、本発明の一実施形態では、電池要素と外部電極との間の界面領域において、電極層の端部（引出し部に相当）と外部電極とが互いに嵌り合う上記嵌合部分が所定の間隔をおいて２つ以上形成されていることが好ましい（図１、図３および図５参照）。　 Further, in one embodiment of the present invention, in the interface region between the battery element and the external electrode, the fitting portion where the end portion (corresponding to the drawer portion) of the electrode layer and the external electrode are fitted to each other is at a predetermined interval. It is preferable that two or more of them are formed (see FIGS. 1, 3 and 5). It was
　上記では、図１、図３および図５に図示される態様に従い、単一の上記嵌合部分に着目して説明した。この点につき、電池要素と外部電極との間の界面領域において、当該嵌合部分が所定の間隔をおいて２つ以上形成されていると、嵌合部分により奏され得る技術的効果をより好適に奏することができる。 In the above description, the single fitting portion has been focused on according to the embodiments shown in FIGS. 1, 3 and 5. In this regard, if two or more fitting portions are formed at predetermined intervals in the interface region between the battery element and the external electrode, the technical effect that can be achieved by the fitting portions is more preferable. Can be played.
　具体的には、『電極層と外部電極との間の一体焼結が容易ではない部分』が２つ以上ある場合において、両者が嵌り合った嵌合部分が２つ以上形成されていると、嵌合部分の数が多いことにより、電極層１０の端部（引出し部に相当）と外部電極との接触面積が相対的に増大する部分の数を増やすことができる。これにより、いわゆる“アンカー効果”が生じる箇所の数が増え、電極層と外部電極との間の相互接続を向上できる箇所の数も増やすことができる。 Specifically, when there are two or more "parts where integral sintering is not easy between the electrode layer and the external electrode", and two or more fitting parts in which the two are fitted are formed. Due to the large number of fitting portions, the number of portions where the contact area between the end portion (corresponding to the drawer portion) of the electrode layer 10 and the external electrode relatively increases can be increased. As a result, the number of locations where the so-called "anchor effect" occurs increases, and the number of locations where the interconnection between the electrode layer and the external electrode can be improved can also be increased.
　その結果、固体電池の充放電が繰り返し実施されたとしても、両者の相互接続を好適に維持できる箇所も増やすことが可能となる。これに加えて、電極層の端部と外部電極との接触面積が増大する部分の数が増えることで、接触抵抗もより小さくすることができ、それにより固体電池の内部抵抗もより小さくできる。それ故、全体として固体電池の充放電をより好適に実施することが可能となる。 As a result, even if the solid-state battery is repeatedly charged and discharged, it is possible to increase the number of places where the interconnection between the two can be appropriately maintained. In addition to this, the contact resistance can be made smaller by increasing the number of portions where the contact area between the end of the electrode layer and the external electrode increases, so that the internal resistance of the solid-state battery can also be made smaller. Therefore, it becomes possible to more preferably charge and discharge the solid-state battery as a whole.
　本発明の一実施形態は下記態様を採ることもできる。図７は、本発明の別実施形態に係る固体電池を模式的に示す拡大断面図である。 One embodiment of the present invention can also take the following aspects. FIG. 7 is an enlarged cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention.
　上述のように、本発明の一実施形態にて、電極層の端部（引出し部に相当）と外部電極とにより形成される「嵌合部分」は、電極層および外部電極とが互いに嵌り合う関係であれば、両者の一方が凸部形態を有し他方が凹部形態を有する態様に限定されない。上記図１～図６に図示する態様では、電極層が凸部形態を有し外部電極が凹部形態を有する態様に基づいている。しかしながら、上記図１～図６に図示する態様は、当該嵌合部分を形成するための一例にすぎず、図７に示すように外部電極が凸部形態を有し電極層が凹部形態を有する態様に基づくこともできる。 As described above, in one embodiment of the present invention, the electrode layer and the external electrode are fitted to each other in the "fitting portion" formed by the end portion (corresponding to the drawer portion) of the electrode layer and the external electrode. The relationship is not limited to a mode in which one of the two has a convex shape and the other has a concave shape. The embodiment shown in FIGS. 1 to 6 is based on an embodiment in which the electrode layer has a convex shape and the external electrode has a concave shape. However, the embodiment shown in FIGS. 1 to 6 is only an example for forming the fitting portion, and as shown in FIG. 7, the external electrode has a convex shape and the electrode layer has a concave shape. It can also be based on aspects.
　具体的には、一例として、電極層１０ＩＩＩが凹部形態の端部１０ａＩＩＩ（引出し部に相当）を有し、外部電極２００ＩＩＩが凸部形態の端面を局所的に有することもできる。この場合、かかる嵌合部分では、凹部形状の電極層１０ＩＩＩの端部１０ａＩＩＩに外部電極２００ＩＩＩの凸部形状部分が局所的に差し込まれるように構成されている。換言すれば、凹部形状の電極層１０ＩＩＩが外部電極２００ＩＩＩの凸部形状部分を嵌合可能に受容している。 Specifically, as an example, the electrode layer 10III may have a concave end portion 10aIII (corresponding to a drawer portion), and the external electrode 200III may locally have a convex end surface. In this case, in such a fitting portion, the convex portion-shaped portion of the external electrode 200III is locally inserted into the end portion 10aIII of the concave-shaped electrode layer 10III. In other words, the concave electrode layer 10III mateably accepts the convex portion of the external electrode 20033.
　この場合にも、『電極層１０ＩＩＩと外部電極２００ＩＩＩとの間の一体焼結が容易ではない部分』にて両者が嵌り合った嵌合部分が形成されている。そのため、かかる嵌合により、従前の固体電池と比べて、電極層１０ＩＩＩの端部１０ａＩＩＩ（引出し部に相当）と外部電極２００ＩＩＩとの接触面積を相対的に増大させることができる。これにより、いわゆる“アンカー効果”が供され、電極層１０ＩＩＩと外部電極２００ＩＩＩとの間の相互接続の程度を向上させることができる。 Also in this case, a fitting portion in which both are fitted is formed in the "part where integral sintering is not easy between the electrode layer 10III and the external electrode 200III". Therefore, such fitting can relatively increase the contact area between the end portion 10aIII (corresponding to the drawer portion) of the electrode layer 10III and the external electrode 200III as compared with the conventional solid-state battery. This provides a so-called "anchor effect" and can improve the degree of interconnection between the electrode layer 10III and the external electrode 200III.
［本発明の固体電池の製造方法］
　以下、図１に示す本発明の一実施形態に係る固体電池の製造方法について説明する。 [Method for manufacturing solid-state battery of the present invention]
Hereinafter, a method for manufacturing a solid-state battery according to an embodiment of the present invention shown in FIG. 1 will be described.
　本発明の一実施形態に係る固体電池は、スクリーン印刷法等の印刷法、グリーンシートを用いるグリーンシート法、またはそれらの複合法により製造することができる。 The solid-state battery according to the embodiment of the present invention can be manufactured by a printing method such as a screen printing method, a green sheet method using a green sheet, or a composite method thereof.
（未焼成積層体の形成工程）
　まず、各基材（例えばＰＥＴフィルム）上に固体電解質層用ペースト、正極材層用ペースト、正極集電体層用ペースト、負極材層用ペースト、負極集電体層用ペースト、絶縁部用ペースト、および保護層用ペーストを塗工する。 (Step of forming unfired laminate)
First, on each base material (for example, PET film), a paste for a solid electrolyte layer, a paste for a positive electrode material layer, a paste for a positive electrode current collector layer, a paste for a negative electrode material layer, a paste for a negative electrode current collector layer, and a paste for an insulating portion. , And the protective layer paste is applied.
　各ペーストは、正極活物質、負極活物質、導電性材料、固体電解質材料、絶縁性物質、および焼結助剤から成る群から適宜選択される各層の所定の構成材料と、有機材料を溶剤に溶解した有機ビヒクルとを湿式混合することによって作製することができる。正極材層用ペーストは、例えば、正極活物質、導電材料、固体電解質材料、有機材料および溶剤を含む。負極材層用ペーストは、例えば、負極活物質、導電材料、固体電解質材料、有機材料および溶剤を含む。正極集電体層用ペースト／負極集電体層用ペーストとしては、例えば、銀、パラジウム、金、プラチナ、アルミニウム、銅、およびニッケルから成る群から少なくとも一種選択されてよい。固体電解質層用ペーストは、例えば、固体電解質材料、焼結助剤、有機材料および溶剤を含む。保護層用ペーストは、例えば、絶縁性物質材料、有機材料および溶剤を含む。絶縁部用ペーストは、例えば絶縁性物質材料、有機材料および溶剤を含む。 Each paste uses a predetermined constituent material of each layer appropriately selected from the group consisting of a positive electrode active material, a negative electrode active material, a conductive material, a solid electrolyte material, an insulating material, and a sintering aid, and an organic material as a solvent. It can be produced by wet mixing with a dissolved organic vehicle. The paste for the positive electrode material layer includes, for example, a positive electrode active material, a conductive material, a solid electrolyte material, an organic material and a solvent. The paste for the negative electrode material layer includes, for example, a negative electrode active material, a conductive material, a solid electrolyte material, an organic material and a solvent. As the paste for the positive electrode current collector layer / the paste for the negative electrode current collector layer, at least one may be selected from the group consisting of, for example, silver, palladium, gold, platinum, aluminum, copper, and nickel. The paste for the solid electrolyte layer includes, for example, a solid electrolyte material, a sintering aid, an organic material and a solvent. Protective layer pastes include, for example, insulating material materials, organic materials and solvents. Insulating pastes include, for example, insulating material materials, organic materials and solvents.
　湿式混合ではメディアを用いることができ、具体的には、ボールミル法またはビスコミル法等を用いることができる。一方、メディアを用いない湿式混合方法を用いてもよく、サンドミル法、高圧ホモジナイザー法またはニーダー分散法等を用いることができる。 Media can be used in wet mixing, and specifically, a ball mill method, a viscomill method, or the like can be used. On the other hand, a wet mixing method that does not use a medium may be used, and a sand mill method, a high-pressure homogenizer method, a kneader dispersion method, or the like can be used.
　所定の固体電解質材料と焼結助剤と、有機材料を溶剤に溶解した有機ビヒクルとを湿式混合することによって、所定の固体電解質層用ペーストを作製することができる。なお、既述のとおり、固体電解質材としては、例えば、ナシコン構造を有するリチウム含有リン酸化合物、ペロブスカイト構造を有する酸化物、ガーネット型またはガーネット型類似構造を有する酸化物等が挙げられる。ナシコン構造を有するリチウム含有リン酸化合物としては、ＬｉxＭy（ＰＯ4）3（１≦ｘ≦２、１≦ｙ≦２、Ｍは、Ｔｉ、Ｇｅ、Ａｌ、ＧａおよびＺｒからなる群より選ばれた少なくとも一種）が挙げられる。ナシコン構造を有するリチウム含有リン酸化合物の一例としては、例えば、Ｌｉ1.2Ａｌ0.2Ｔｉ1.8（ＰＯ4）3等が挙げられる。ペロブスカイト構造を有する酸化物の一例としては、Ｌａ0.55Ｌｉ0.35ＴｉＯ3等が挙げられる。ガーネット型またはガーネット型類似構造を有する酸化物の一例としては、Ｌｉ7Ｌａ3Ｚｒ2Ｏ12等が挙げられる。 A paste for a predetermined solid electrolyte layer can be prepared by wet-mixing a predetermined solid electrolyte material, a sintering aid, and an organic vehicle in which an organic material is dissolved in a solvent. As described above, examples of the solid electrolyte material include a lithium-containing phosphoric acid compound having a pearcon structure, an oxide having a perovskite structure, an oxide having a garnet type or a garnet type similar structure, and the like. As the lithium-containing phosphoric acid compound having a pear-con structure, Li x My (PO 4 ) 3 (1 ≦ x ≦ 2, 1 ≦ y ≦ 2, M is from the group consisting of Ti, Ge, Al, Ga and Zr. At least one selected). Examples of the lithium-containing phosphoric acid compound having a pear-con structure include Li 1.2 Al 0.2 Ti 1.8 (PO 4 ) 3 . Examples of oxides having a perovskite structure include La 0.55 Li 0.35 TiO 3 and the like. As an example of an oxide having a garnet type or a garnet type-like structure, Li 7 La 3 Zr 2 O 12 and the like can be mentioned.
　正極材層用ペーストに含まれる正極活物質材としては、例えば、ナシコン型構造を有するリチウム含有リン酸化合物、オリビン型構造を有するリチウム含有リン酸化合物、リチウム含有層状酸化物、およびスピネル型構造を有するリチウム含有酸化物等から成る群から少なくとも一種を選択する。 Examples of the positive electrode active material contained in the positive electrode material layer paste include a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing layered oxide, and a spinel-type structure. At least one is selected from the group consisting of lithium-containing oxides and the like.
　絶縁部用ペーストに含まれる絶縁性物質材料としては、例えば、ガラス材、セラミック材等から構成され得る。保護層用ペーストに含まれる絶縁性物質材料としては、例えば、ガラス材、セラミックス材、熱硬化性樹脂材、光硬化性樹脂材等から成る群から選択される少なくとも１種を用いることが好ましい。 The insulating material contained in the paste for the insulating portion may be composed of, for example, a glass material, a ceramic material, or the like. As the insulating material material contained in the protective layer paste, for example, it is preferable to use at least one selected from the group consisting of glass materials, ceramic materials, thermosetting resin materials, photocurable resin materials and the like.
　ペーストに含まれる有機材料は特に限定されないが、ポリビニルアセタール樹脂、セルロース樹脂、ポリアクリル樹脂、ポリウレタン樹脂、ポリ酢酸ビニル樹脂およびポリビニルアルコール樹脂などから成る群から選択される少なくとも１種の高分子材料を用いることができる。溶剤は上記有機材料を溶解可能な限り特に限定されず、例えば、トルエンおよび／またはエタノールなどを用いることができる。 The organic material contained in the paste is not particularly limited, but at least one polymer material selected from the group consisting of polyvinyl acetal resin, cellulose resin, polyacrylic resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin and the like can be used. Can be used. The solvent is not particularly limited as long as it can dissolve the organic material, and for example, toluene and / or ethanol can be used.
　負極材層用ペーストに含まれる負極活物質材としては、例えば、Ｔｉ、Ｓｉ、Ｓｎ、Ｃｒ、Ｆｅ、Ｎｂ、および、Ｍｏからなる群より選ばれる少なくとも一種の元素を含む酸化物、黒鉛－リチウム化合物、リチウム合金、ナシコン型構造を有するリチウム含有リン酸化合物、オリビン型構造を有するリチウム含有リン酸化合物、およびスピネル型構造を有するリチウム含有酸化物等から成る群から少なくとも一種から選択する。 Examples of the negative electrode active material contained in the paste for the negative electrode material layer include an oxide containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo, and graphite-lithium. It is selected from at least one group consisting of a compound, a lithium alloy, a lithium-containing phosphoric acid compound having a pearcon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing oxide having a spinel-type structure, and the like.
　焼結助剤としては、リチウム酸化物、ナトリウム酸化物、カリウム酸化物、酸化ホウ素、および酸化ケイ素からなる群から選択される少なくとも１種であり得る。 The sintering aid may be at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, and silicon oxide.
　塗工したペーストを、３０～５０℃に加熱したホットプレート上で乾燥させることで、基材（例えばＰＥＴフィルム）上に所定厚みを有する固体電解質層シート、正極層シート、および負極層シートをそれぞれ形成する。 The coated paste is dried on a hot plate heated to 30 to 50 ° C. to form a solid electrolyte layer sheet, a positive electrode layer sheet, and a negative electrode layer sheet having a predetermined thickness on a substrate (for example, PET film), respectively. Form.
　次に、各シートを基材から剥離する。剥離後、積層方向に沿って電池構成単位の各構成要素のシートを順に積層する。 Next, peel off each sheet from the base material. After peeling, the sheets of each component of the battery constituent unit are laminated in order along the stacking direction.
　当該積層の段階において、電極シートの側部領域にスクリーン印刷により固体電解質部シート又は絶縁部シートを設ける。具体的には、電極シートの側部のうち後刻に外部電極が接続される部分を除く外部電極非接続部分を取り囲むように固体電解質部シート又は絶縁部シートを設ける。 At the stage of laminating, a solid electrolyte sheet or an insulating sheet is provided in the side region of the electrode sheet by screen printing. Specifically, a solid electrolyte portion sheet or an insulating portion sheet is provided so as to surround the external electrode non-connecting portion excluding the portion of the side portion of the electrode sheet to which the external electrode is connected later.
　次いで、所定圧力（例えば約５０～約１００ＭＰａ）による熱圧着と、これに続く所定圧力（例えば約１５０～約３００ＭＰａ）での等方圧プレスを実施することが好ましい。以上により、所定の積層体を形成することができる。 Next, it is preferable to perform thermocompression bonding at a predetermined pressure (for example, about 50 to about 100 MPa) and subsequent isotropic pressure pressing at a predetermined pressure (for example, about 150 to about 300 MPa). From the above, a predetermined laminated body can be formed.
　次いで、かかる積層体の端面を所定の型に押し付ける。これにより、積層体端面（側面に相当）から電極層となる部分の端部（具体的には外部電極接続側の端部）を露出させることができる。 Next, the end face of the laminated body is pressed against a predetermined mold. As a result, the end portion (specifically, the end portion on the external electrode connection side) of the portion to be the electrode layer can be exposed from the end surface (corresponding to the side surface) of the laminated body.
（焼成工程）
　電極層となる部分の端部が露出した所定の積層体を焼成に付す。当該焼成は、窒素ガス雰囲気中で例えば６００℃～１０００℃で加熱することで実施する。積層体については、必要に応じて個片化工程を更に付してもよい。なお、電極層の端部露出は積層体の端面を所定の型に押し付ける方法に限定されない。電極層の電極材層の材料組成と固体電解質部又は絶縁部の材料組成を事前に適宜調整することで、焼成時に収縮挙動の違いにより電極層の端部を露出させることも可能である。 (Baking process)
A predetermined laminate in which the end of the portion to be the electrode layer is exposed is subjected to firing. The firing is carried out by heating at, for example, 600 ° C. to 1000 ° C. in a nitrogen gas atmosphere. The laminated body may be further subjected to an individualization step if necessary. The exposure of the end of the electrode layer is not limited to the method of pressing the end face of the laminated body against a predetermined mold. By appropriately adjusting the material composition of the electrode material layer of the electrode layer and the material composition of the solid electrolyte portion or the insulating portion in advance, it is possible to expose the end portion of the electrode layer due to the difference in shrinkage behavior during firing.
　次いで、端部が露出した電極層を備える積層体の側面に外部電極をつける。具体的には、露出した電極層の端部を覆うように積層体（電池要素に相当）の側面に外部電極をつける。外部電極は正極層と負極層にそれぞれ電気的に接続可能に設ける。例えば、スパッタ等により外部電極を形成することが好ましい。特に限定されるものではないが、外部電極としては、銀、金、プラチナ、アルミニウム、銅、スズ、およびニッケルから選択される少なくとも一種から構成されることが好ましい。更に、スパッタ、スプレーコート等により外部電極が覆われない程度で保護層を設けることが好ましい。 Next, an external electrode is attached to the side surface of the laminate having the electrode layer with the exposed end. Specifically, an external electrode is attached to the side surface of the laminate (corresponding to a battery element) so as to cover the end of the exposed electrode layer. External electrodes are provided so as to be electrically connectable to the positive electrode layer and the negative electrode layer, respectively. For example, it is preferable to form an external electrode by sputtering or the like. Although not particularly limited, the external electrode is preferably composed of at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel. Further, it is preferable to provide a protective layer to the extent that the external electrode is not covered by sputtering, spray coating or the like.
　以上により、本発明の一実施形態に係る固体電池５００を好適に製造することができる（図１参照）。 From the above, the solid-state battery 500 according to the embodiment of the present invention can be suitably manufactured (see FIG. 1).
　得られた本発明の一実施形態にかかる固体電池では、『電極層１０と外部電極２００との間の一体焼結が容易ではない部分』にて両者が嵌り合った嵌合部分が形成されている。かかる嵌合により、従前の固体電池と比べて、電極層１０の端部１０ａ（引出し部に相当）と外部電極２００との接触面積を相対的に増大させることができる。これにより、いわゆる“アンカー効果”が供され、それにより電極層１０と外部電極２００との間の相互接続の程度を向上させることができる。その結果、両者の相互接続を好適に維持することが可能となる。その他の作用効果等については、上記で既に述べているため、記載の重複を回避する観点から省略する。 In the obtained solid-state battery according to the embodiment of the present invention, a fitting portion in which both are fitted is formed at "a portion where integral sintering is not easy between the electrode layer 10 and the external electrode 200". There is. By such fitting, the contact area between the end portion 10a (corresponding to the drawer portion) of the electrode layer 10 and the external electrode 200 can be relatively increased as compared with the conventional solid-state battery. This provides a so-called "anchor effect", which can improve the degree of interconnection between the electrode layer 10 and the external electrode 200. As a result, it becomes possible to suitably maintain the interconnection between the two. Since other actions and effects have already been described above, they will be omitted from the viewpoint of avoiding duplication of description.
　以上、本発明の一実施形態について説明してきたが、本発明の適用範囲のうちの典型例を例示したに過ぎない。従って、本発明はこれに限定されず、種々の改変がなされ得ることを当業者は容易に理解されよう。 Although one embodiment of the present invention has been described above, it merely exemplifies a typical example of the scope of application of the present invention. Therefore, those skilled in the art will easily understand that the present invention is not limited to this, and various modifications can be made.
　本発明の一実施形態に係る固体電池は、蓄電が想定される様々な分野に利用することができる。あくまでも例示にすぎないが、本発明の一実施形態に係る固体電池は、モバイル機器などが使用される電気・情報・通信分野（例えば、携帯電話、スマートフォン、スマートウォッチ、ノートパソコンおよびデジタルカメラ、活動量計、アームコンピューター、電子ペーパーなどのモバイル機器分野）、家庭・小型産業用途（例えば、電動工具、ゴルフカート、家庭用・介護用・産業用ロボットの分野）、大型産業用途（例えば、フォークリフト、エレベーター、湾港クレーンの分野）、交通システム分野（例えば、ハイブリッド車、電気自動車、バス、電車、電動アシスト自転車、電動二輪車などの分野）、電力系統用途（例えば、各種発電、ロードコンディショナー、スマートグリッド、一般家庭設置型蓄電システムなどの分野）、医療用途（イヤホン補聴器などの医療用機器分野）、医薬用途（服用管理システムなどの分野）、ならびに、ＩｏＴ分野、宇宙・深海用途（例えば、宇宙探査機、潜水調査船などの分野）などに利用することができる。 The solid-state battery according to the embodiment of the present invention can be used in various fields where storage is expected. Although only an example, the solid-state battery according to the embodiment of the present invention is used in the fields of electricity, information, and communication (for example, mobile phones, smartphones, smart watches, laptop computers, digital cameras, activities, etc.) in which mobile devices and the like are used. Mobile device fields such as scales, arm computers, and electronic paper), home / small industrial applications (eg, power tools, golf carts, home / nursing / industrial robot fields), large industrial applications (eg, forklifts, etc.) Elevators, Gulf Cranes), Transportation Systems (eg, Hybrid Vehicles, Electric Vehicles, Buses, Trains, Electric Assisted Bicycles, Electric Motorcycles, etc.), Power Systems Applications (eg, Power Generation, Road Conditioners, Smart Grids) , General household installation type power storage system, etc.), medical use (medical equipment field such as earphone hearing aid), pharmaceutical use (dose management system, etc.), IoT field, space / deep sea use (for example, space exploration) It can be used in fields such as aircraft and submersible research vessels).
　１０、１０Ｉ，１０ＩＩ，１０ＩＩＩ　　電極層
　１０ａ、１０ａＩ，１０ａＩＩ，１０ａＩＩＩ　　電極層
　１０Ａ、１０ＡＩ、１０ＡＩＩ、１０Ａ’　　正極層
　１０Ｂ、１０ＢＩ、１０ＢＩＩ、１０Ｂ’　　負極層
　
　２０、２０Ｉ，２０ＩＩ，２０ＩＩＩ，２０’　　固体電解質層
　
　１００、１００Ｉ、１００ＩＩ、１００’　電池要素
　２００，２００’　　　　　　　　　　　　　　　　　外部電極
　３００、３００Ｉ、３００ＩＩ、３００’　　　電池要素と外部電極との間の界面領域
　５００、５００Ｉ，５００ＩＩ，５００’　　固体電池 10, 10I, 10II, 10III Electrode layer 10a, 10aI, 10aII, 10aIII Electrode layer 10A, 10AI, 10AII, 10A'Positive layer 10B, 10BI, 10BII, 10B' Negative layer
20, 20I, 20II, 20III, 20'Solid electrolyte layer
100, 100I, 100II, 100'Battery element 200,200' External electrode 300, 300I, 300II, 300' Interface area between battery element and external electrode 500, 500I, 500II, 500'Solid-state battery

Claims (13)

  1. 　正極層、負極層、および該正極層と該負極層との間に介在する固体電解質層を備えた電池要素と、
    　電池要素の表面に設けられた外部電極と
    を備え、
    　前記電池要素と前記外部電極との界面領域において、前記正極層と前記負極層の少なくとも一方の電極層と前記外部電極とが互いに嵌り合った嵌合部分が形成されている、固体電池。     A battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer.
    Equipped with an external electrode provided on the surface of the battery element,
    A solid-state battery in which a fitting portion in which at least one of the positive electrode layer and the negative electrode layer and the external electrode are fitted to each other is formed in an interface region between the battery element and the external electrode.
  2. 　前記電極層および前記外部電極の一方が、該電極層および該外部電極の他方に部分的に差し込まれるように設けられている、請求項１に記載の固体電池。 The solid-state battery according to claim 1, wherein one of the electrode layer and the external electrode is provided so as to be partially inserted into the electrode layer and the other of the external electrodes.
  3. 　前記界面領域において、前記電極層および前記外部電極の一方が前記電極層および前記外部電極の他方により部分的に取り囲まれている、請求項１又は２に記載の固体電池。 The solid-state battery according to claim 1 or 2, wherein in the interface region, one of the electrode layer and the external electrode is partially surrounded by the electrode layer and the other of the external electrodes.
  4. 　前記嵌合部分において、凸部形状の前記電極層の端部が凹部形状の前記外部電極に差し込まれている、請求項１～３のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 3, wherein the end portion of the convex electrode layer is inserted into the concave external electrode in the fitting portion.
  5. 　前記篏合部分がアンカー効果提供部分である、請求項１～４のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 4, wherein the combined portion is an anchor effect providing portion.
  6. 　前記界面領域が、略平面形状のメイン界面領域と該メイン部分に連続する非平面形状のサブ界面領域とから構成されている、請求項１～５のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 5, wherein the interface region is composed of a substantially planar main interface region and a non-planar sub-interface region continuous with the main portion.
  7. 　電池の断面視で、前記非平面形状の前記サブ界面領域に前記嵌合部分が位置づけられている、請求項６に記載の固体電池。 The solid-state battery according to claim 6, wherein the fitting portion is positioned in the sub-interface region of the non-planar shape in a cross-sectional view of the battery.
  8. 　電池の断面視で、前記界面領域が傾斜形態をなしている、請求項１～７のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 7, wherein the interface region has an inclined shape in a cross-sectional view of the battery.
  9. 　前記電極層の外部電極非接続側の端部が固体電解質部又は絶縁部により取り囲まれており、前記非平面形状の前記サブ界面領域において、該固体電解質部又は該絶縁部と前記外部電極とが互いに嵌り合った嵌合部分が更に形成されている、請求項１～８のいずれかに記載の固体電池。 The end of the electrode layer on the non-connecting side of the external electrode is surrounded by a solid electrolyte portion or an insulating portion, and in the non-planar shape of the sub-interface region, the solid electrolyte portion or the insulating portion and the external electrode are formed. The solid-state battery according to any one of claims 1 to 8, wherein the fitting portions that are fitted to each other are further formed.
  10. 　前記界面領域において、前記嵌合部分が所定の間隔をおいて２つ以上形成されている、請求項１～９のいずれかに記載の固体電池。　 The solid-state battery according to any one of claims 1 to 9, wherein two or more fitting portions are formed at predetermined intervals in the interface region. It was
  11. 　前記電極層は少なくとも電極材層を有して成り、該電極材層と前記外部電極とが互いに異なる材料からなっている、請求項１～１０のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 10, wherein the electrode layer has at least an electrode material layer, and the electrode material layer and the external electrode are made of different materials.
  12. 　前記電極材層が非金属材から構成される一方、前記外部電極が金属材から構成される、請求項１１に記載の固体電池。 The solid-state battery according to claim 11, wherein the electrode material layer is made of a non-metal material, while the external electrode is made of a metal material.
  13. 　前記正極層および前記負極層がリチウムイオンを吸蔵放出可能な層となっている、請求項１～１２のいずれかに記載の固体電池。 The solid-state battery according to any one of claims 1 to 12, wherein the positive electrode layer and the negative electrode layer are layers capable of storing and releasing lithium ions.
PCT/JP2021/037860 2020-10-16 2021-10-13 Solid-state battery WO2022080404A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020100683A1 (en) * 2018-11-16 2020-05-22 株式会社村田製作所 Solid battery
WO2020100682A1 (en) * 2018-11-16 2020-05-22 株式会社村田製作所 Solid-state battery

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020100683A1 (en) * 2018-11-16 2020-05-22 株式会社村田製作所 Solid battery
WO2020100682A1 (en) * 2018-11-16 2020-05-22 株式会社村田製作所 Solid-state battery

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