WO2019078307A1 - Électrode composite et batterie au lithium entièrement solide - Google Patents

Électrode composite et batterie au lithium entièrement solide Download PDF

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Publication number
WO2019078307A1
WO2019078307A1 PCT/JP2018/038876 JP2018038876W WO2019078307A1 WO 2019078307 A1 WO2019078307 A1 WO 2019078307A1 JP 2018038876 W JP2018038876 W JP 2018038876W WO 2019078307 A1 WO2019078307 A1 WO 2019078307A1
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lithium
solid electrolyte
layer
active material
electrode
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PCT/JP2018/038876
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English (en)
Japanese (ja)
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努 西▲崎▼
田村　哲也
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セントラル硝子株式会社
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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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • 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 composite electrode containing an electrode active material and a solid electrolyte, which is used for an all solid lithium battery.
  • Secondary batteries are used in portable devices such as mobile phones and notebook computers, transport machines for automobiles and aircraft, and power storage devices for power leveling, and the energy density is required to be improved in any application. There is. At present, the practical secondary battery with the highest energy density is a lithium ion battery, and studies are underway to try to further increase the energy density while maintaining safety. As part of that research, research is being conducted on an all-solid-state battery (a battery using a solid electrolyte instead of an electrolytic solution), which is an improvement technology of a lithium ion battery.
  • the all-solid battery is packaged separately by repeatedly laminating the negative electrode layer, the separator layer (lithium ion conductive layer), the positive electrode layer, and the electron conductive layer, since the negative electrode, the electrolyte and the positive electrode constituting the battery are all solid. Since it is possible to manufacture a battery having a series structure even if it is not used, it is considered to be suitable for automobiles and power storage. Furthermore, by increasing the proportion of the oxide among the negative electrode active material, the solid electrolyte, and the positive electrode active material, the all solid battery can be expected to have an effect on safety and high temperature durability in addition to energy density improvement.
  • Patent Document 1 In an electrode of a lithium ion battery using an electrolytic solution that has been put into practical use, the electrolytic solution that has penetrated into the gap between the positive electrode and the negative electrode functions as a lithium ion conduction path.
  • Patent Document 1 in order to form a lithium ion conduction path to an electrode active material in an electrode layer using a solid electrolyte, a sintered body obtained by combining an electrode active material and an oxide-based solid electrolyte is used as an electrode. Is being considered.
  • Patent Documents 2 and 3 In order to form a lithium ion conduction path to an electrode active material, it has been studied to use a composite in which the electrode active material and a solid electrolyte are mixed as an electrode.
  • Patent Document 4 discloses an electrode laminate in which one or more solid electrolyte layers and one or more active material layers are alternately stacked in order to secure lithium ion conductivity and obtain high capacity density.
  • Patent Document 5 discloses a manufacturing method for obtaining an active material molded body and a solid electrolyte layer by firing a first film and a second film obtained using an inkjet in order to efficiently manufacture an electrode complex. ing.
  • Patent Documents 1 to 3 when the solid electrolyte is randomly distributed in the electrode, there is a solid electrolyte which does not contact the other solid electrolyte and does not contribute to the formation of the lithium ion conduction path. There is a problem that the percentage of the electrode active material still present in the electrode but not contributing to charge and discharge is not small because the solid electrolyte is locally distributed and the lithium ion conduction path does not reach the surface of the electrode. There was a point.
  • Patent Document 4 since sintering is not performed in the manufacturing process and there is a limit to increasing the density of the active material layer and reducing the width, an electrode that is present in the electrode but does not contribute to charge and discharge There is a problem that the proportion of active material is not small. Also in Patent Document 5, since the first film is formed by discharging the first liquid material containing the formation material of the active material by the ink jet, and the width of the first film can not be thinner than the size of the droplets of the ink jet. There has been a problem that the width of the molded article becomes large, and the proportion of the electrode active material which is present in the electrode but does not contribute to charge and discharge is not small.
  • the present invention has been made to solve the problems of the prior art, and by reducing the solid electrolyte not contributing to the formation of the lithium ion conduction path, many electrode activities included in the electrode are realized.
  • An object of the present invention is to provide an electrode having a capacity closer to the theoretical capacity than in the past by contributing a substance to charge and discharge.
  • the inventors of the present invention can provide a lithium ion conduction path in a range in which lithium ions can permeate from the electrode active material, if the lithium ion conduction path is regularly provided in the electrode. It has been found that more electrode active materials in the electrode can contribute to charge and discharge, and the present invention has been completed.
  • the present invention is a composite electrode which is a sintered body containing an electrode active material and a solid electrolyte, and the composite electrode is a sheet-like electrode active material containing an oxide-based electrode active material.
  • Layer and sheet-like solid electrolyte layer containing an oxide-based solid electrolyte are alternately arranged, and the width of the electrode active material layer is 10 nm or more and 20 ⁇ m or less, and the width of the solid electrolyte layer is Provided is a composite electrode having a thickness of 10 nm or more and 20 ⁇ m or less, wherein the solid electrolyte layer penetrates the composite electrode.
  • a method of manufacturing the composite electrode is a method of obtaining a laminate in which a layer containing an electrode active material or a precursor thereof and a layer containing a solid electrolyte or a precursor thereof are alternately laminated. Also provided is a method for producing a composite electrode, comprising the steps of: sintering the laminate; and obtaining a laminated sintered body in which an electrode active material layer and a solid electrolyte layer are alternately laminated.
  • Electrode active materials contained in the electrode are contributed to charge and discharge, and a capacity closer to the theoretical capacity than in the past is realized.
  • An electrode can be provided.
  • FIG. 1 is a schematic view of a composite electrode 10 of the present invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram of the composite electrode 21 of this invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram of the all-solid-state lithium ion battery using the composite electrode 10 of this invention.
  • (A), (b) The schematic diagram of the manufacture process of the composite electrode 10 of this invention.
  • FIG. 1 is a schematic view of a lithium ion battery 101 of the present invention.
  • (A)-(d) is a schematic view of the manufacturing process of the lithium ion battery 101 of the present invention.
  • FIG. 6 is a diagram showing a production flow of LTO calcined particles in Example 1;
  • FIG. 6 is a diagram showing a production flow of LLTO pre-sintered body particles of Example 1.
  • FIG. 6 is a diagram showing a production flow from temporary firing body particles to an arrayed sintered body of Example 1. The figure which shows the powder XRD result which grind
  • the composite electrode 10 of the present invention is a composite electrode which is a sintered body containing an electrode active material and a solid electrolyte, and in the composite electrode 10, as shown in the figure, It is characterized by having a solid electrolyte layer 13 penetrating in the thickness direction of the composite electrode.
  • the composite electrode 10 has a flat plate shape, and the sheet-like electrode active material layer 11 parallel to the thickness direction 15 of the composite electrode and the sheet parallel to the thickness direction 15 of the composite electrode It is preferable that the solid electrolyte layers 13 in the shape of a circle are alternately arranged. In addition, as shown in FIG. 1, it is preferable that the solid electrolyte layer 13 penetrate the composite electrode 10 in the thickness direction of the composite electrode 10. When solid electrolyte 13 penetrates composite electrode 10, solid electrolyte layer 13 can be disposed near electrode active material layer 11, and the lithium ion conduction path can be spread over the entire composite electrode 10. .
  • the lithium ion conduction path can be made to reach the surface of the composite electrode 10, and the lithium ion can be easily from the separator layer 35 described later to the solid electrolyte layer 13. Can be moved.
  • both ends of the alternate arrangement of the electrode active material layer 11 and the solid electrolyte layer 13 are the electrode active material layer 11 in FIG. 1, the end is not limited to the electrode active material layer 11, and the solid electrolyte layer 13 is It may be an end. The same applies to the other composite electrodes in the present embodiment.
  • the thickness C of the composite electrode 10 is preferably 10 ⁇ m or more and 3 mm or less, more preferably 15 ⁇ m or more and 1 mm or less, and particularly preferably 20 ⁇ m or more and 500 ⁇ m or less. However, the thickness C may be 100 ⁇ m or more.
  • the depth Y of the composite electrode 10 depends on the desired device size and battery capacity, and can be determined appropriately.
  • the composite electrode is preferably compact.
  • the degree of compactness can be quantified by the porosity.
  • the method of using a density is mentioned.
  • Porosity (%) 100-(actual density / theoretical density) x 100
  • the theoretical density can be referred to a database or calculated from the composition and crystal structure.
  • the porosity is preferably 40% or less, more preferably 30% or less, and particularly preferably 25% or less.
  • the porosity is exemplified by the porosity calculated by the above equation based on the actual density measured by the Archimedes method, that is, the porosity calculated by the Archimedes method.
  • Both the capacity density and the power density of the composite electrode are preferably large.
  • the capacity density can be increased by increasing the proportion of the active material.
  • the power density can be increased by increasing the conductivity of electrons and lithium ions.
  • the power density can be increased by increasing the proportion of the solid electrolyte and the conductive additive in the composite electrode.
  • coexistence of capacity density and power density can be realized by arranging the electrode active material layer and the solid electrolyte layer efficiently.
  • the capacity density is the power capacity per weight or volume of the battery
  • the power density is the maximum amount of power that can be taken out per weight or volume of the battery.
  • the initial charge capacity and / or the initial discharge capacity of the composite electrode 10 is preferably 10 mAh / g or more, more preferably 30 mAh / g or more, and particularly preferably 50 mAh / g or more.
  • the initial charge capacity and the initial discharge capacity of the composite electrode 10 were obtained by laminating the positive electrode, the separator layer, and the negative electrode in this order using the composite electrode 10 as a positive electrode, a dry polymer electrolyte or the like as a separator layer, and metallic lithium as a negative electrode. It can be evaluated by performing a charge and discharge test at a temperature of 60 ° C. and a rate of 0.002 mA / cm 2 using an all solid type cell.
  • the above capacity means the capacity per unit mass of the composite electrode obtained by dividing the capacity of the all solid cell by the mass of the composite electrode.
  • the width B of the electrode active material layer 11 shown in FIG. 1 is preferably 10 nm or more and 20 ⁇ m or less, more preferably 15 ⁇ m or less, still more preferably 10 ⁇ m or less, and particularly preferably 6 ⁇ m or less . If the width B of the electrode active material layer 11 is too small, the amount of the electrode active material contained in the composite electrode 10 may be small. When the width B of the electrode active material layer 11 is too large, there is a possibility that lithium ions are less likely to conduct to the electrode active material at the center of the electrode active material layer 11. In particular, by setting the width B of the electrode active material layer to 10 ⁇ m or less, more electrode active materials in the electrode can contribute to charge and discharge.
  • the width A of the solid electrolyte layer 13 is preferably 10 nm or more and 20 ⁇ m or less, more preferably 10 ⁇ m or less, and particularly preferably 5 ⁇ m or less.
  • the width A of the solid electrolyte layer 13 is too small, the cross-sectional area of the layer is reduced, the crystallinity of the particles constituting the layer is reduced, or the interface between the solid electrolyte layer 13 and the electrode active material layer 11 is It becomes difficult to ensure sufficient lithium ion conductivity due to resistance increase and the like.
  • the width A of the solid electrolyte layer 13 is too large, the proportion of the electrode active material contained in the composite electrode 10 decreases, and the capacity density of the composite electrode 10 decreases.
  • the electrode active material layer 11 and the solid electrolyte layer 13 do not necessarily have to be flat layers, and may be curved. In addition, there may be partial defects, and adjacent electrode active material layers 11 or adjacent solid electrolyte layers 13 may be in contact with each other.
  • the electrode active material layer 11 and the solid electrolyte layer 13 are preferably parallel to the thickness direction 15 of the composite electrode, but may be inclined up to about 45 degrees.
  • the aspect ratio (C / B or C / A) obtained by dividing the thickness C of the composite electrode 10 by the width A of the solid electrolyte layer 13 or the width B of the electrode active material layer 11 is preferably 10 or more. It is more preferably 50 or more, and particularly preferably 100 or more.
  • the volume of the solid electrolyte layer 13 is reduced by decreasing the width A of the solid electrolyte layer 13 (as C / A increases). The volume can be increased to increase the capacity density of the composite electrode 10.
  • the width B of the electrode active material layer 11 is reduced (as C / B increases), the electrode active material layer 11 is thinner, so lithium ions can be conducted to the central portion of the electrode active material layer 11 .
  • the width X of the composite electrode 10 determined by the widths of the electrode active material layer 11 and the solid electrolyte layer 13 and the number of layers to be laminated, the desired device size, battery capacity and It can be determined appropriately in consideration of mechanical strength and the like.
  • the volume ratio of the electrode active material to the solid electrolyte contained in the composite electrode 10 is preferably 5: 5 or more and 9.5: 0.5 or less. A larger amount of the electrode active material is preferable because the capacity of the composite electrode 10 is increased.
  • the electrode active material layer 11 is a layer containing an electrode active material.
  • the electrode active material include oxide-based electrode active materials, carbon materials, and other materials.
  • oxide-based electrode active material a spinel type or ramsdellite type lithium titanate (a part of elements constituting lithium titanate may be replaced with another element, even if another element is doped
  • Other elements include Mg, Cr, Zn, Co, Fe, Ni, Mn, Al, Zr, Nb, Sn, Mo, and W.
  • LiMg 1/2 Ti 3/2 Examples include O 4 , LiCo 1/2 Ti 3/2 O 4 , LiZn 1/2 Ti 3/2 O 4 , LiCrTiO 4 , LiFeTiO 4, etc.
  • transition metal oxides eg, titanium oxide, niobium oxide, oxide
  • spinel lithium manganate spinel lithium manganate nickel ( LiMn 1.5 Ni 0.5 O 4 )
  • artificial graphite natural graphite, graphitizable carbon, non-graphitizable carbon (hard carbon) having a spacing of (002) plane of 0.37 nm or more, and a spacing of (002) plane of 0. 0. Graphite etc. of 34 nm or less are mentioned.
  • Other materials include elemental silicon, silicon compounds, elemental sulfur, metal sulfides (eg, Li 2 S, SnS, NiS, etc.), metal phosphides (eg, Ni 5 P 4 , NiP 2 etc.), Li 3 PS 4 can be mentioned.
  • the electrode active material layer 11 may contain a sintering aid, a conductive aid, and the like.
  • the sintering aid includes borate, silicate and phosphate, and mixtures thereof.
  • metals such as gold, silver, copper and nickel, conductive oxides such as tin oxide, zinc oxide, titanium oxide and indium tin oxide, materials such as carbon, particles, fibers and rods , Tubes, etc. can be used.
  • Examples of carbon-based conductive assistants include carbon fibers, carbon black, carbon nanotubes, carbon nanofibers, graphene, graphite and the like.
  • the solid electrolyte layer 13 is a layer containing a solid electrolyte.
  • the solid electrolyte include oxide-based solid electrolytes, sulfide-based solid electrolytes, and polymer-based solid electrolytes.
  • perovskite-type oxides containing lithium garnet-type oxides containing lithium, lithium phosphate (Li 3 PO 4 ), lithium niobate (LiNbO 3 ), and LAGP with NASICON structure (Li 1 + x Al) x Ge 2-x (PO 4 ) 3 (0 ⁇ x ⁇ 1), LATP with NASICON structure (Li 1 + x Al x Ti 2-x (PO 4 ) 3 (0 ⁇ x ⁇ 1)), LZP structure with NASICON structure (Li 1 + 4x Zr 2-x (PO 4 ) 3 (0 ⁇ x ⁇ 0.4, part of LZP metal elements may be replaced by another metal element, even if other metal elements are doped As another metal element, Na, Sr, Ca, Mg, La, Y, Sc, Ce, In, Al, Ge, Ti, V, etc. may be mentioned.
  • the lithium-containing perovskite oxide is an oxide represented by ABO 3 having a perovskite crystal structure, and at least one A site is selected from the group consisting of La, Sr, Ba, Na, Ca and Nd. It is preferable that the element contains a species element and Li, and the B site contains at least one element selected from the group consisting of Ti, Ta, Cr, Fe, Co, Ga and Nb.
  • Other elements include Na, K, Rb, Ag, Tl, Mg, Sr, Ca, Ba, Nb, Ta, Ru, Cr, Mn, Fe, Co, Al, Ga, Si, Ge, Zr, hf, Pr, Nd, Sm, Gd, Dy, Y, Eu, Tb and the like, specifically, La (2/3) -x Sr x Li x TiO 3, Li x La 2/3 Ti 1- x Al x O 3 and the like.
  • garnet-type oxides include Li 7 La 3 Zr 2 O 12 , Li 5 La 3 Nb 2 O 12 , Li 5 La 3 Ta 2 O 12 , and Li 6 La 2 BaTa 2 O 12 .
  • glass-based sulfides for example, Li 2 S-P 2 S 5 , Li 2 S-SiS 2 -P 2 S 5 -LiI, etc.
  • algirodite-type sulfides for example, Li 7 PS
  • Li 6 PS 5 Cl Li 6 PS 5 Br
  • Li 6 PS 5 I etc.
  • thiolysicon based sulfides eg, Li 4-x Ge 1-x P x S 4 (0 ⁇ x ⁇ 1 etc)
  • Li 7 P 3 S 11 Li 10 GeP 2 S 12 (LGPS), Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (LiSiPSCl), Li 9.6 P 3 S 12 And Li-Sn-Si-P-S (LSSPS) system.
  • the dry polymer electrolyte layer etc. which contain lithium salt in polymers, such as a polyethylene oxide, are mentioned
  • the solid electrolyte layer 13 may contain a sintering aid, a conductive aid, and the like.
  • the sintering aid may, for example, be a borate, a silicate, a phosphate, a mixture thereof or the like, or a material used for the electrode active material layer.
  • metals such as gold, silver, copper and nickel, conductive oxides such as tin oxide, zinc oxide, titanium oxide and indium tin oxide, materials such as carbon, particles, fibers and rods , Tubes, etc. can be used.
  • Examples of carbon-based conductive assistants include carbon fibers, carbon black, carbon nanotubes, carbon nanofibers, graphene, graphite and the like.
  • the volume of the solid electrolyte contained in the solid electrolyte layer is preferably 40% or more of the volume of the solid electrolyte layer, more preferably 50% or more, and it may be a dense body of 100% solid electrolyte. The higher the volume of the solid electrolyte contained in the solid electrolyte layer, the easier it is to form the lithium ion conduction path in the thickness direction of the composite electrode.
  • a pattern may be formed in which the solid electrolyte layer is divided into a portion mainly composed of the solid electrolyte and a portion mainly composed of the electrode active material.
  • the portion 57 mainly composed of an island-like solid electrolyte that forms a sea-island structure when viewed from above is mainly composed of a sea-like electrode active material in the thickness direction.
  • the portion 57 mainly composed of a strip-like solid electrolyte and the strip-like electrode active material are mainly composed.
  • a laminated sintered body 61 is prepared as shown in FIG. 6 (b), and these laminated sintered bodies 61 are cut.
  • the portion 57 mainly composed of the strip-like solid electrolyte penetrates the electrode active material layer 11 and the electrode active material portion 55 in the thickness direction. It can be arranged.
  • the materials of the electrode active material and the solid electrolyte are not particularly limited, but from the viewpoints of safety and heat resistance, it is preferable to contain an oxide, and in the case of mainly oxide, the electrode active material
  • the weight fraction of the oxide in the layer 11 or the solid electrolyte layer 13 is preferably 60% or more, more preferably 70% or more, and particularly preferably 80% or more.
  • the composite electrode obtained by sintering is a dense sintered body, the volume percentage occupied by the oxide in the composite electrode is preferably 30% or more, and is 50% or more. Is more preferable, and 70% or more is particularly preferable.
  • a composite is formed by sintering, it is preferable that both the electrode active material layer 11 and the solid electrolyte layer 13 contain an oxide.
  • a composite electrode 21 having a metal layer 23 as shown in FIG. 2 may be used as the composite electrode of the present invention.
  • the position of the metal layer 23 is not particularly limited, but as in the solid electrolyte layer 13-electrode active material layer 25-metal layer 23-electrode active material layer 25-solid electrolyte layer 13, the metal layer 23 is a solid electrolyte layer 13. Parallel to the center of the electrode active material layer 25.
  • the electron conductivity in the composite electrode 21 can be enhanced by the metal layer 23, and in particular, parallel to the solid electrolyte layer 13, it is easy to move electrons between the electrode active material layer 25 and the current collector layer. can do.
  • the width D of the metal layer 23 is preferably 1 nm or more and 10 ⁇ m or less, and as the material thereof, gold, silver, copper, nickel, aluminum, niobium, an alloy of two or more of these, and the like can be mentioned. Alternatively, two or more metals may be used to form the metal layer. Since the metal layer 23 can not conduct lithium ions, when the metal layer 23 is sandwiched between two electrode active material layers 25 as shown in FIG. 2, the width E of the electrode active material layer 25 does not have the metal layer 23. It is preferable that the width is half the width B of the electrode active material layer 11.
  • Lithium-ion battery In the lithium ion battery of the present invention, a negative electrode layer for absorbing and desorbing lithium ions, a separator layer for conducting lithium ions, and a positive electrode layer for absorbing and desorbing lithium ions are laminated in this order as a negative electrode layer or a positive electrode layer. It is characterized by using the composite electrode of the present invention.
  • FIG. 3 is a view showing the lithium ion battery 31 of the present invention, in which the composite electrode 10, the separator layer 35 and the counter electrode layer 33 are laminated in order. Furthermore, normally, metal electrodes (not shown) are provided on the composite electrode layer 10 and the counter electrode layer 33.
  • the positive electrode and the negative electrode change depending on the voltage of the electrode active material contained in each of the composite electrode 10 and the counter electrode layer 33, and when the composite electrode 10 is a positive electrode, the counter electrode layer 33 becomes a negative electrode, and the composite electrode 10 is a negative electrode.
  • the counter electrode layer 33 is a positive electrode.
  • the composite electrode when the composite electrode includes spinel type or ramsdellite type lithium titanate as an electrode active material, lithium titanate is often used as a negative electrode active material of a lithium ion secondary battery, but metal lithium When a material having a charge / discharge potential relatively lower than that of lithium titanate, such as lithium alloy, is used for the counter electrode (negative electrode), it can be used as a positive electrode active material.
  • the composite electrode of the present invention can be used as an electrode of a primary battery by using metal lithium or a lithium alloy as a counter electrode.
  • a lithium ion battery includes both a primary battery and a secondary battery, and in addition to a battery using metal lithium or a lithium alloy as an electrode, electricity in which lithium ions move between a positive electrode and a negative electrode Includes the entire chemical device.
  • the separator layer 35 is a layer that easily conducts lithium ions and hardly conducts electrons.
  • the lithium ion battery 31 may be an electrolyte battery, and the separator layer 35 may be a film impregnated with the electrolyte.
  • a film for a separator non-woven fabric or porous sheet made of polyolefin such as polypropylene and polyethylene, cellulose, paper, glass fiber and the like is used. It is preferable that these films be micro-porous so that the electrolyte can penetrate and the ions can easily permeate.
  • the negative electrode layer, the positive electrode layer, and the separator film may be disposed in the electrolytic solution and may be disposed in a coin-type, cylindrical-type, square-type metal can, or a laminate exterior body. It may be sealed.
  • the lithium ion battery 31 may be an all solid battery, and the separator layer 35 may be a solid electrolyte layer.
  • a solid electrolyte contained in a solid electrolyte layer a sulfide type solid electrolyte and an oxide type solid electrolyte can be used.
  • glass-based sulfides for example, Li 2 S-P 2 S 5 , Li 2 S-SiS 2 -P 2 S 5 -LiI, etc.
  • algirodite-type sulfides for example, Li 7 PS
  • Li 6 PS 5 Cl for example, Li 6 PS 5 Br
  • Li 6 PS 5 I etc.
  • thiolysicon based sulfides eg, Li 4-x Ge 1-x P x S 4 (0 ⁇ x ⁇ 1 etc)
  • Li 7 P 3 S 11 Li 10 GeP 2 S 12 (LGPS), Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (LiSiPSCl), Li 9.6 P 3 S 12 And Li-Sn-Si-P-S (LSSPS), etc.
  • a perovskite-type lithium lanthanum niobate Li x La (1-x) / 3 NbO 3
  • a current collector layer may be provided on the surfaces of the composite electrode 10 and the counter electrode layer 33.
  • the current collector layer is provided to exchange electricity with the outside during charge and discharge in the all solid battery, and an electron conductive material, usually an electron conductive substance such as metal or carbon material itself, or an electron conductive substance. Are dispersed in a matrix of oxide or the like.
  • an electron conductive material usually an electron conductive substance such as metal or carbon material itself, or an electron conductive substance.
  • a metal constituting the current collector layer at least one metal selected from the group consisting of nickel, copper, silver, gold and the like can be used.
  • the current collector layer can be obtained by applying a metal paste and baking it in an atmosphere containing a reducing gas containing hydrogen and the like. In the present invention, if materials are appropriately selected, it is also possible to obtain an all-solid battery by collectively sintering all of the current collector layer, the composite electrode, the separator layer, and the counter electrode layer.
  • a layer containing the electrode active material or its precursor hereinafter referred to as an electrode active material layer green sheet
  • a layer containing a solid electrolyte or its precursor hereinafter referred to as a solid electrolyte layer green sheet
  • a green sheet laminate also referred to as a precursor of a composite electrode because it becomes a composite electrode by sintering
  • the laminate is sintered to obtain a laminated sintered body 41.
  • the laminated sintered body 41 is cut out in a plane perpendicular to the plane direction of each layer, and the electrode active material layer 11 and the solid electrolyte layer 13 are alternately arranged in a flat plate. An arrayed sintered body is obtained.
  • the arrayed sintered body can be used as the composite electrode 10.
  • the sintering step may be performed after the cutting step by replacing the sintering step and the cutting step. That is, a green sheet laminate is cut out in a plane perpendicular to the plane direction of each layer, and an electrode active material layer green sheet and a solid electrolyte layer green sheet are alternately arranged to obtain an array on a flat plate, and the array is fired A flat plate-like arrayed sintered body may be obtained by bonding.
  • the laminated sintered body 41 can also be used as a composite electrode without cutting, and can be used, for example, as the negative electrode band 103 or the positive electrode band 107 of the lithium ion battery 101 described later.
  • the precursor of an electrode active material or a solid electrolyte is a material which becomes an electrode active material or a solid electrolyte by heating, such as baking and sintering.
  • the precursor of lithium titanate may be a compound containing lithium and titanium, or may be a mixture of a lithium source and a titanium source.
  • a lithium source a halide, carbonate, hydroxide or the like of lithium can be used, and as a titanium source, an oxide, halide, carbonate, hydroxide or the like of titanium can be used.
  • a precursor of lithium titanate can be obtained by solvothermal treatment of a mixture containing a lithium source, a titanium source and a solvent.
  • the lithium lithium titanate precursor may be a compound containing lithium, titanium and lanthanum, or a mixture of a lithium source, a titanium source and a lanthanum source, It is also good.
  • a lithium source a halide, carbonate, hydroxide or the like of lithium can be used, and as a titanium source, an oxide, halide, carbonate, hydroxide or the like of titanium can be used.
  • a lanthanum source chlorides, oxychlorides, hydroxides, oxides, and nitrates of lanthanum can be used.
  • a precursor of lithium lanthanum titanate can be obtained by solvothermal treatment of a mixture containing a lithium source, a titanium source, a lanthanum source and a solvent.
  • a paste containing an electrode active material or a precursor thereof and a paste containing a solid electrolyte or a precursor thereof are prepared.
  • the paste may contain an organic binder such as acrylic resin, PVA (polyvinyl alcohol), PVB (polyvinyl butyral) and the like.
  • the organic binder maintains the shape of the green sheet, is thermally decomposed by heating, and is removed from the sintered body.
  • the specific surface area of the electrode active material or its precursor calculated by BET method using nitrogen adsorption is preferably 0.5 m 2 / g or more, more preferably 1.2 m 2 / g, and 13 m 2 It is more preferable if it is / g or more.
  • the specific surface area of the solid electrolyte or the precursor thereof is preferably 0.5 m 2 / g or more, more preferably 3 m 2 / g, and further preferably 15 m 2 / g or more. Since the specific surface area tends to increase as the primary particle size decreases, the uniformity of the application process and the sintering process can be obtained by using an electrode active material having a large specific surface area or a precursor thereof, or a solid electrolyte or a precursor thereof. The sinterability can be enhanced, the width of the electrode active material layer or the solid electrolyte layer in the laminated sintered body can be reduced, and the porosity can be reduced.
  • a paste containing an electrode active material or a precursor thereof is applied onto a substrate and dried to form an electrode active material green sheet, and a solid electrolyte or a precursor thereof is contained.
  • a paste containing an electrode active material or a precursor thereof is applied and dried on a substrate to form an electrode active material green sheet, and a paste containing a solid electrolyte or a precursor thereof is further applied and dried thereon.
  • a method in which a solid electrolyte green sheet is formed, the base material is peeled off, and then the binder is removed by heating to form a laminate.
  • the laminate of the electrode active material green sheet and the solid electrolyte green sheet is sintered to obtain a laminated sintered body in which the electrode active material layer and the solid electrolyte layer are laminated.
  • the temperature is preferably 200 ° C. or more and 1300 ° C. or less, preferably 300 ° C. or more and 1250 ° C. or less, more preferably 400 ° C. or more and 1200 ° C. or less, and 500 ° C. or more and 1150 ° C. It is further preferable that the temperature is not higher than ° C. In order to prevent the side reaction of the electrode active material, heating at 1300 ° C. or less is more preferable, and heating at 500 ° C. or more is preferable in order to obtain a dense sintered body.
  • any of an air atmosphere, an inert atmosphere such as nitrogen, a highly oxidizing atmosphere such as oxygen, and a reducing atmosphere such as hydrogen can be used.
  • the environment may be a reduced pressure environment or a pressurized environment, for example, an environment in the range of 0.1 Pa to 1 MPa in absolute pressure, preferably 1 Pa to 500 kPa.
  • the temperature holding time can be appropriately changed according to the temperature etc., but considering production efficiency etc, it is preferably 48 hours or less, more preferably 24 hours or less.
  • the temperature holding time may be a short time of 1 hour or less, and further, the holding time may be 0 minutes and heating may be stopped immediately after reaching the target temperature.
  • the cooling method is also not particularly limited, but may be natural cooling (cooling in a furnace) or may be cooled more rapidly than natural cooling, and a step of holding a predetermined temperature for a predetermined time during cooling You may provide.
  • lithium lanthanum titanate when contained as the solid electrolyte, lithium lanthanum titanate crystal-grows at 700 ° C. or higher, and therefore the resistance of the solid electrolyte layer can be reduced by setting the sintering temperature to 800 ° C. or higher.
  • spinel type lithium titanate can be obtained from the precursor of lithium titanate by setting sintering temperature to 400 degreeC or more and 1000 degrees C or less. Furthermore, by setting the sintering temperature to more than 1000 ° C., ramsdellite lithium titanate can be obtained from a precursor of lithium titanate.
  • sintering in the first stage is more than 1000 ° C., preferably 1100 ° C. or more and 1500 ° C. or less, more preferably 1150 ° C. or more and 1300 ° C.
  • the spinel type lithium titanate can be obtained from the precursor of lithium titanate by carrying out the second stage sintering at 400 ° C. or more and 1000 ° C. or less, and the second stage of sintering is performed from the precursor of lithium lanthanum titanate, Perovskite-type lithium lanthanum titanate can be obtained.
  • lithium lanthanum titanate can be a compact sintered body and the lithium ion conductivity can be enhanced by the step of heating at temperatures exceeding 1000 ° C.
  • lithium titanate is of the ramsdellite type, and by subsequent sintering at 1000 ° C. or less, spinel type lithium titanate more suitable as an electrode active material can be obtained.
  • the ramsdellite lithium titanate contained in the sintered body is maintained for 2 hours or more in a temperature range of 400 ° C. to 1000 ° C., preferably in a temperature range of 500 ° C. to 950 ° C.
  • a phase change to spinel-type lithium titanate can be made by staying for 4 hours or more, more preferably for 8 hours or more in a temperature range of 600 ° C. to 900 ° C. By staying in a temperature range of 600 ° C. to 900 ° C. for 10 hours or more, preferably 15 hours or more, substantially single phase spinel lithium titanate can be obtained.
  • the second-stage sintering may be performed during cooling, or may be heated to 400 ° C. or lower after returning to normal temperature to perform the second-stage sintering.
  • the time of staying in the temperature range of 400 ° C. or more and 1000 ° C. or less during cooling or heating after the first stage sintering can also be included in the staying time in the second stage sintering.
  • lithium titanate and lithium lanthanum titanate are generated from the precursor of lithium titanate and the precursor of lithium lanthanum titanate by heating. Heating causes a change in the crystalline phase from the precursor and / or an improvement in crystallinity. The change in crystal phase and / or the improvement in crystallinity can be confirmed by powder X-ray diffraction. The change in crystal phase is reflected in the change in diffraction pattern, and the improvement in crystallinity is reflected in the X-ray diffraction pattern as the decrease in width of diffraction line.
  • Li 0.94 Ti 2 O 4 [ICDD No. 01-088-0609], lithium titanate having a perovskite crystal structure Lanthanum, for example, Li 3x La 2 / 3-x TiO 3 (0 ⁇ x ⁇ 1/6) [ICDD Nos. 01-074-4217, 00-046-0467, 01-087-0935, 00-046-0466, etc.] Generates.
  • a plane perpendicular to the plane direction of each layer means a plane perpendicular to the plane direction of each layer and an angle within ⁇ 45 degrees.
  • the cutting method is not particularly limited, laser processing, electron beam processing, plasma processing, ultrasonic processing, gas cutting, diamond grinding, etc. can be used as a method capable of cutting a hard sintered body into a thin plate shape.
  • the metal layer 23 In order to obtain the composite electrode 21 having the metal layer 23, the metal layer 23 needs to be laminated in the laminate.
  • the metal layer 23 can be formed by coating / screen-printing a paste in which metal fine particles are dispersed, preparing a green sheet from the paste, and depositing metal under vacuum.
  • a lithium lanthanum titanate precursor used when forming a solid electrolyte layer green sheet be obtained by solvothermal treatment of a mixture containing a Ti element source, a La element source, a Li element source, and a solvent.
  • Aqueous solution preparation process In the aqueous solution preparation step, an aqueous solution containing La cation and Ti cation is prepared.
  • the La cation include La 3+
  • examples of the Ti cation include Ti 4+ .
  • Each of the La cation and the Ti cation may form a complex using water, ammonia, an oxide ion, a hydroxide ion, a counter anion described later, or the like as a ligand.
  • As a counter anion of La cation and Ti cation in addition to oxide ion and hydroxide ion, for example, chlorine-containing anion such as chloride ion, nitrate anion and the like can be mentioned.
  • the above counter anions may be used alone or in combination of two or more.
  • the aqueous solution is prepared, for example, by dissolving a lanthanum compound that generates La cation by dissolution and a titanium compound that generates Ti cation by dissolution in water or an acidic aqueous solution.
  • these lanthanum compounds and titanium compounds for example, chlorides, oxychlorides, hydroxides, oxides, nitrates and the like can be mentioned, and chlorides or oxychlorides are preferred because they are easy to obtain and inexpensive. Is preferred.
  • nitrate is preferable from the viewpoint of easy dissolution. It does not specifically limit as a form of said lanthanum compound and a titanium compound, For example, liquids, such as solid, such as a powder, aqueous solution, etc. are mentioned.
  • Each of the above-mentioned lanthanum compound and titanium compound may be used alone or in combination of two or more.
  • the aqueous solution prepared in the aqueous solution preparation step preferably has a pH of less than 7, ie, acidic.
  • La cation exhibits high aqueous solution in the strongly acidic to weakly acidic region, but Ti cation exhibits high water solubility only in the strongly acidic region. Therefore, from the viewpoint of stability, the aqueous solution prepared in the aqueous solution preparation step is preferably strongly acidic (for example, pH 3 or less).
  • Simultaneous precipitation process In the coprecipitation process step, precipitation comprising an oxide and / or hydroxide of lanthanum and an oxide and / or hydroxide of titanium by mixing the aqueous solution obtained in the aqueous solution preparation step with a basic aqueous solution.
  • the method for mixing the aqueous solution obtained in the aqueous solution preparation step and the basic aqueous solution is not particularly limited, and examples thereof include a method in which the aqueous solution obtained in the aqueous solution preparation step is dropped or sprayed onto the basic aqueous solution.
  • the pH of the basic aqueous solution is preferably 8 or more from the viewpoint of the precipitation rate.
  • the basic aqueous solution is not particularly limited, and examples thereof include aqueous ammonia and an aqueous lithium hydroxide solution. Ammonia water is preferred in terms of availability and low cost. Further, from the viewpoint of preventing contamination to the solid electrolyte, an aqueous lithium hydroxide solution in which the alkali cation is a lithium ion, that is, a cation constituting the solid electrolyte is preferable.
  • the molar equivalent of the base of the basic aqueous solution used in the simultaneous precipitation process step is the molar equivalent of the counter anion of the La cation and Ti cation in the aqueous solution obtained in the aqueous solution preparation process (excluding oxide ion and hydroxide ion) More is preferable, and a large excess (for example, about twice or more) is more preferable.
  • the molar equivalent of the base of the basic aqueous solution is larger than the molar equivalent of the above counter anion, the basicity of the mixed solution can be sufficiently maintained even after the aqueous solution obtained in the aqueous solution preparation step and the basic aqueous solution are mixed.
  • the precipitate obtained in the coprecipitation process step is separated and washed as appropriate.
  • the separation method is not particularly limited, and examples thereof include centrifugation, decantation, and filtration.
  • the solvent used for washing is not particularly limited, and water is preferably exemplified from the viewpoint of easy availability and low cost.
  • the precipitate obtained in the simultaneous precipitation treatment step can prevent a large mass loss caused by the detachment of the organic ligand at the time of sintering, which is generated by the sol-gel method.
  • the pressure is higher than atmospheric pressure by mixing a solid or solution containing La cation and Ti cation such as precipitates obtained in the simultaneous precipitation treatment step, a compound of lithium element source, and a solvent Heat under to obtain a precursor.
  • the compound of the lithium element source is not particularly limited, and examples thereof include lithium carbonate, lithium chloride, lithium fluoride, lithium hydroxide, lithium nitrate, lithium acetate, and hydrates of these. These lithium compounds may be used alone or in combination of two or more. Further, the form of the lithium compound may be, for example, a solid such as a powder or an aqueous solution, and is not particularly limited.
  • the content ratio of La element to Ti element in the mixture before the solvothermal treatment process be La / Ti ⁇ 0.66.
  • La (OH) 3 other than LTO or LLTO is difficult to be retained by firing because more La than the electrode complex containing the lithium lanthanum titanate having the target composition requires is difficult to remain after firing. It is difficult to form an impurity phase such as La 2 O 3 or La 2 Ti 2 O 7 .
  • hydrothermal treatment using water as a solvent is mainly performed.
  • the hydrothermal treatment refers to a compound synthesis method or a crystal growth method performed in the presence of high temperature and high pressure hot water, and a chemical reaction which does not occur in an aqueous solution at normal temperature and pressure may progress.
  • an aqueous solution containing a lithium element is added to a solid or solution containing a La cation and a Ti cation, and a high temperature and high pressure treatment is performed to obtain a lithium element which is water soluble at normal temperature and pressure.
  • Complex chloride can be incorporated into the complex salt, and the complex salt is separated from the solvent to obtain a precursor.
  • water is used as a solvent in the hydrothermal treatment, the same effect can be expected also by a method (solvothermal method) using a solvent other than water (for example, an organic solvent etc.).
  • the absolute pressure is higher than atmospheric pressure and lower than 8.7 MPa, and the temperature is 60 ° C. or more and 300 ° C. or less, more preferably, the absolute pressure is 0.15 MPa or more. It is preferable to heat at about 0 MPa or less and at a temperature of 60 ° C. to 250 ° C. for about 1 hour to 100 hours. If the pressure and temperature are in the above ranges, the reaction is likely to proceed, impurities are less likely to be generated, and a high-pressure pressure container is not required, which is less likely to cause an increase in manufacturing cost. Moreover, productivity is hard to fall that reaction time is in the said range.
  • An acid may be further added to the hydrothermally treated body obtained in the solvothermal treatment step to carry out the second solvothermal treatment step.
  • the solvothermal treatment step is a first solvothermal treatment step.
  • the acid both inorganic acids and organic acids can be used, and hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid and the like can be used.
  • the addition amount of the acid the difference from the molar ratio (Li / Ti) of lithium to titanium in the molar ratio of acid to titanium (acid / Ti) is 0.1 ⁇ [(Li / Ti)-(acid / Ti) It is preferable to satisfy
  • pH of the solution after addition of an acid is 8 or more and 14 or less.
  • the La element source may be added together with the acid when performing the second solvothermal treatment without adding it in the first aqueous solution preparation step.
  • the solvothermal treatment is performed on the precipitate obtained by the simultaneous precipitation method, but the single salt of Ti element and the single element of La element obtained by other than the simultaneous precipitation method.
  • the solvothermal treatment may be performed on a mixture containing a salt, a simple salt of Li element and a solvent.
  • the oxide and / or hydroxide of lanthanum are mentioned. It does not specifically limit as a monosalt of Ti element, The oxide and / or hydroxide of titanium are mentioned.
  • the monosalt of Li element is not particularly limited, and examples thereof include lithium carbonate, lithium chloride, lithium fluoride, lithium hydroxide, lithium nitrate, lithium acetate, and hydrates of these.
  • the average particle diameter of the Ti single salt is preferably 100 nm or less, more preferably 50 nm or less, and particularly preferably 30 nm or less. If the particles of the Ti single salt are in the above range, complex chloride of Li and Ti is likely to progress during the solvothermal treatment.
  • the precursor of lithium titanate used when forming the electrode active material layer green sheet can be obtained by not using the La element source in the process of manufacturing the above-mentioned lithium lanthanum titanate precursor.
  • the precursor obtained in the solvothermal treatment step may be dried.
  • conditions of a drying process 60 degreeC or more and 250 degrees C or less, 1 hour or more and 10 hours or less are mentioned, for example.
  • the precursor obtained in the solvothermal treatment step may be used as it is as a green sheet, it is possible to use as a green sheet temporary calcinated particles obtained by temporarily calcining a lithium titanate precursor and a lithium lanthanum titanate precursor. preferable.
  • the lithium titanate or the lithium titanate precursor is preferably heated at 250 ° C. or more and 1500 ° C. or less, more preferably 400 ° C. or more and 1300 ° C. or less, to form lithium titanate or lithium titanate or The precursor or lithium lanthanum titanate or a precursor thereof is produced.
  • Pre-baking may be performed at a lower temperature to produce only lithium titanate, and lithium lanthanum titanate may not be produced, or pre-baking may be performed at a higher temperature to produce both lithium titanate and lithium lanthanum titanate. You may
  • the laminate of the electrode active material layer and the solid electrolyte layer before or after sintering is cut to obtain the composite electrode 10, and then the separator layer 35 and the counter electrode layer 33 are obtained.
  • the lithium ion battery can also be obtained by forming the composite electrode, the separator, and the counter electrode adjacent to each other without performing the cutting step.
  • the lithium ion battery 101 of the present invention will be described.
  • the current collector 109, the negative electrode band 103, the separator band 105, the positive electrode band 107, and the current collector 111 are adjacent in this order.
  • the negative electrode band 103 is composed of negative electrode active material sheets 113a to 113d and solid electrolyte sheets 123a to 123c stacked alternately. All these layers (all seven layers depicted in FIG. 7) constitute a composite electrode and act as one negative electrode.
  • the positive electrode band 107 is composed of positive electrode active material sheets 117a to 117d and solid electrolyte sheets 127a to 127c alternately stacked, and all of these layers constitute a composite electrode and function as one positive electrode.
  • the negative electrode band 103 and the positive electrode band 107 correspond to the composite electrode 10 of the present invention.
  • the current collectors 109a to 109g and the current collectors 111a to 111g are stacked, respectively, to form current collectors 109 and 111.
  • the separator sheets 115a to 115g are stacked to form one separator band 105.
  • the solid electrolyte sheets 123a to 123c By sandwiching the solid electrolyte sheets 123a to 123c between the negative electrode active material sheets 113a to 113d, a lithium ion conduction path to the negative electrode active material of the negative electrode active material sheet can be provided.
  • the positive electrode active material sheets 117a to 117d lithium ion conductive paths to the positive electrode active material in the positive electrode active material sheet can be provided by the solid electrolyte sheets 127a to 127c.
  • the outermost layer of the negative electrode band 103 is the negative electrode active material sheet 113a and the negative electrode active material sheet 113d in FIG. 7, the outermost layer is not limited to the negative electrode active material sheet, and the solid electrolyte sheet is the outermost surface. It may be a layer of Similarly for the positive electrode zone 107, the solid electrolyte sheet may be the outermost layer.
  • the same material as the above-described electrode active material layer 11 can be used for the negative electrode active material sheets 113a to 113d or the positive electrode active material sheets 117a to 117d.
  • the negative electrode active material and the positive electrode active material may use the same material, they are generally different materials.
  • a known oxide-based positive electrode active material such as lithium transition metal oxide is used as the positive electrode active material of the positive electrode zone 107. It can be used.
  • both negative electrode band 103 and positive electrode band 107 have solid electrolyte sheets 123a-c or 127a-c, but they necessarily have solid electrolyte sheets in both negative electrode band and positive electrode band. It may not be necessary, and only the negative electrode band or the positive electrode band may have the solid electrolyte sheet.
  • the solid electrolyte sheet is provided only in the negative electrode zone and not in the positive electrode zone, the negative electrode zone corresponds to the electrode complex of the present invention, and the positive electrode zone does not correspond to the electrode composite of the present invention.
  • solid electrolyte layer 13 The same material as the solid electrolyte layer 13 described above can be used for the solid electrolyte sheets 123a to 123c.
  • the solid electrolyte sheets 123a to 123c and 127a to 127c may be the same material or different materials.
  • the separator sheets 115a to 115g can use the same material as the separator layer 35 described above, but are preferably formed of a sulfide-based or oxide-based solid electrolyte.
  • the separator sheets 115a to 115g may be the same material as or different from the solid electrolyte sheets 123a to 123c.
  • the same materials as the above-described current collector layers can be used.
  • the thickness D of the negative electrode active material sheets 113 a to 113 d and the thickness D of the positive electrode active material sheets 117 a to 117 d are in the same numerical range as the width B of the electrode active material layer 11.
  • the thickness E of the solid electrolyte sheets 123 a-c and 127 a-c is in the same numerical range as the width A of the solid electrolyte layer 13.
  • the width F of the negative electrode band 103 and the width H of the positive electrode band 107 are in the same numerical range as the thickness C of the composite electrode 10.
  • the width F and the width H may or may not be the same value.
  • the negative electrode band 103 it is preferable to combine 100 or more layers of the negative electrode active material sheet 113 and the solid electrolyte sheet 123, preferably 500 or more layers, and more preferably 1000 or more layers. Is particularly preferred. The same applies to the positive electrode band 107.
  • the width G of the separator band 105 is preferably 1 ⁇ m to 300 ⁇ m, more preferably 5 ⁇ m to 100 ⁇ m, and particularly preferably 10 ⁇ m to 30 ⁇ m.
  • the width G is preferably as small as possible as long as short circuit or dielectric breakdown does not occur, but there is a problem of dimensional accuracy in printing process, lamination process and sintering process at the time of production. difficult.
  • the width I of the current collector 109 and the width J of the current collector 111 be as small as possible so long as electrons can be smoothly exchanged with the negative electrode band or the positive electrode band.
  • the width I and the width J may be the same or different.
  • the current collector is required to be a material which is located between the external terminal and the negative electrode zone or the positive electrode zone to facilitate the movement of electrons and which does not cause lithium ion exchange between the negative electrode zone or the positive electrode zone. If the conditions are satisfied, the current collector may be omitted and the negative electrode band or the positive electrode band may be brought into direct contact with the external terminal, or may be substituted by a coating of an electron conductive material prepared by vapor deposition or coating after sintering. It is good.
  • FIGS. 8 (a) to 8 (d) The method of producing the lithium ion battery 101 of the present invention will be described with reference to FIGS. 8 (a) to 8 (d).
  • the current collector 109a, the negative electrode active material green sheet 133a, the separator green sheet 135a, the positive electrode active material green sheet 137a, and the current collector 111a are formed to be adjacent in this order. .
  • the negative electrode active material green sheet 133a is obtained by forming a paste containing the negative electrode active material or a precursor thereof into a predetermined shape and drying it.
  • the separator green sheet 135a is obtained using a paste containing a solid electrolyte or a precursor thereof
  • the positive electrode active material green sheet 137a is obtained using a paste containing a positive electrode active material or a precursor thereof.
  • the specific surface area of the negative electrode active material or the precursor thereof or the positive electrode active material or the precursor thereof calculated by BET method using nitrogen adsorption is preferably 0.5 m 2 / g or more, and 1.2 m 2 / g Is more preferably 13 m 2 / g or more.
  • the specific surface area of the solid electrolyte or the precursor thereof is preferably 0.5 m 2 / g or more, more preferably 3 m 2 / g, and still more preferably 15 m 2 / g or more. Since the specific surface area tends to increase as the primary particle size decreases, the uniformity of the application process and the sintering process can be obtained by using an electrode active material having a large specific surface area or a precursor thereof, or a solid electrolyte or a precursor thereof. The sinterability can be enhanced, the width of the electrode active material layer or the solid electrolyte layer in the laminated sintered body can be reduced, and the porosity can be reduced.
  • the method of forming the paste of each material by printing is mentioned.
  • a printing method an inkjet method of discharging the paste to a predetermined position, an intaglio printing method of transferring the paste into the concave portion of the plate and transferring, a relief printing method of adhering the paste onto the convex portion of the plate and transferring, A lithographic printing method in which a portion with different affinity to the paste is made and the paste is attached to the affinity portion for transfer, a large open portion of fine holes is made in the plate, and the paste passed through the holes under pressure is transferred And the like.
  • the current collector 109b is on the current collector 109a
  • the solid electrolyte green sheet 143a is on the negative electrode active material green sheet 133a
  • the separator green is on the separator green sheet 135a.
  • the sheet 135b is formed on the positive electrode active material green sheet 137a
  • the solid electrolyte green sheet 147a is formed
  • the current collector 111b is formed on the current collector 111a.
  • the current collector 109b is on the current collector 109b
  • the negative electrode active material green sheet 133b is on the solid electrolyte green sheet 143a
  • the separator green is on the separator green sheet 135b.
  • the positive electrode active material green sheet 137b is formed on the solid electrolyte green sheet 147a
  • the current collector 111c is formed on the current collector 111b.
  • the current collector 109c is on the current collector 109c
  • the solid electrolyte sheet 143b is on the negative electrode active material green sheet 133b
  • the separator green sheet is on the separator green sheet 135c.
  • the sheet 135d is formed on the positive electrode active material green sheet 137b
  • the solid electrolyte green sheet 147b is formed
  • the current collector 111d is formed on the current collector 111c.
  • a method of printing in multilayers may be used, or a method may be used in which a green sheet formed on a release film is peeled off, aligned and placed, and pressure-bonded.
  • the process shown in FIG. 8A is omitted, and in FIG. 8B, the current collector 109a, the negative electrode active material green sheet 133a, and the separator green sheet 135a formed in the process shown in FIG. 8A.
  • the current collector 109b, the solid electrolyte green sheet 143a, the separator green sheet 135b, the solid electrolyte green sheet 147a, and the current collector 111b are formed to be adjacent to each other in this order without the positive electrode active material green sheet 137a and the current collector 111a. May be In addition, the formation of the laminate, which is performed by repeating the above steps a predetermined number of times, may be completed by any of the step shown in FIG. 8C and the step shown in FIG.
  • the laminate of the green sheets is sintered to make the negative electrode active material green sheet the negative electrode active material sheet, the positive electrode active material green sheet the positive electrode active material sheet, the separator green sheet the separator sheet, and the solid electrolyte green sheet
  • the lithium ion battery 101 can be obtained as a solid electrolyte sheet.
  • the lithium ion battery 101 can also be obtained without performing a sintering process. That is, a negative electrode active material sheet 113a containing a negative electrode active material, a separator sheet 115a containing a solid electrolyte, and a positive electrode active material sheet 117a containing a positive electrode active material are formed adjacent to each other, and a solid electrolyte sheet 123a containing a solid electrolyte is formed thereon. Forming the separator sheet 115b and the solid electrolyte sheet 127a containing the solid electrolyte is a process repeated.
  • the step of repeating may be solid, instead of starting from forming the negative electrode active material sheet 113a containing a negative electrode active material, the separator sheet 115a containing a solid electrolyte, and the positive electrode active material sheet 117a containing a positive electrode active material. It may start from adjacently forming a solid electrolyte sheet 123a containing an electrolyte, a separator sheet 115b, and a solid electrolyte sheet 127a containing a solid electrolyte.
  • the process to repeat may be completed by forming the negative electrode active material sheet, the separator sheet, and the positive electrode active material sheet adjacent to each other, or forming the solid electrolyte sheet, the separator sheet, and the solid electrolyte sheet adjacent to each other. You may end with
  • a battery assembly in series connection can be obtained.
  • a current collector 109, a negative electrode band 103a, a separator band 105a, a positive electrode band 107a, an electrode band 153, a negative electrode band 103b, a separator band 105b, and a positive electrode band 107b A battery assembly 151 in series connection in which the current collectors 111 are adjacent in this order is obtained.
  • the battery pack 151 connects two lithium ion batteries 101 in series, more lithium ion batteries 101 can be connected in series.
  • the battery assembly 151 is also formed by laminating the respective layers as shown in FIGS. 8 (a) to 8 (d). You can get it.
  • the width of the electrode band 153 is preferably as small as possible so long as electrons are sufficiently conducted and short-circuiting or dielectric breakdown of lithium ions does not occur.
  • the dimensional accuracy of the printing process, the lamination process, and the sintering process at the time of manufacturing And it is difficult to make it less than 10 ⁇ m.
  • the thickness is preferably 10 ⁇ m to 300 ⁇ m, more preferably 10 ⁇ m to 100 ⁇ m, and particularly preferably 10 ⁇ m to 30 ⁇ m.
  • a battery assembly in parallel connection can be obtained.
  • the current collector 163, the negative electrode band 103a, the separator band 105a, the positive electrode band 107a, the current collector 165, the positive electrode band 107b, the separator band 105b, and the negative electrode band 103b The current collector 167 is adjacent in this order, and a battery assembly 161 in parallel connection in which the current collector 165 and the current collector 167 are connected by the connection portion 169 is obtained.
  • the insulator 171 is preferably filled between the connection portion 169 and the negative electrode band 103 a and the like so as not to cause a short circuit without the current collector 163 and the like.
  • the insulator 171 is drawn transparent.
  • a known insulating material can be used as the insulator 171
  • a metal oxide-based insulating material such as alumina, silica, or titania is used in order to obtain a sintered body together with the lithium ion battery 101. It is preferable to do.
  • FIG. 10 shows a structure in which the positive electrode band 107a and the positive electrode band 107b are inside, the positions of the positive electrode band and the negative electrode band may be interchanged and the negative electrode bands 103a and 103b may be inside.
  • the assembled battery 161 is also as shown in FIGS. 8 (a) to 8 (d). Can be obtained by a method of laminating each layer.
  • FIG. 11 shows a battery assembly 181 in which three lithium ion batteries 101 are connected in parallel.
  • the positive electrode bands 107 a and 107 b are electrically connected to the positive electrode band 107 c through the current collector 165, the connection portion 185, and the current collector 183.
  • the negative electrode band 103a is electrically connected to the negative electrode bands 103b and 103c through the current collector 163, the connection portion 169, and the current collector 167.
  • the insulators 171, 173, 175, and 177 are drawn transparent.
  • the widths of the current collectors 165 and the current collectors 167 can be determined in consideration of the dimensional accuracy problems of the printing process, the lamination process, and the sintering process at the time of manufacturing as in the case of the electrode band 153. Unlike in the case of the band 153, there is no need to consider the problem of lithium ion short circuiting or dielectric breakdown, and if the positive or negative band has sufficient electron conductivity, the portion in the positive or negative band is You may omit it.
  • FIG. 12 shows a flow of preparation of lithium titanate (LTO) calcined particles.
  • An aqueous solution of titanium tetrachloride aqueous solution, Ti concentration 3.45 mmol / g, and Cl concentration 13.79 mmol / g was prepared. The aqueous solution was clear and did not form a precipitate upon standing at room temperature. When 1203 g of this aqueous solution was sprayed into 2000 g of 28 mass% ammonia water, a precipitate was formed. The precipitate is separated off, washed with water, dried at 200 ° C. and mechanically disintegrated.
  • Pre-baking treatment process The hydrothermally treated body obtained in the above step was placed in a firing boat made of alumina, and fired in air at 500 ° C. for 10 hours to obtain lithium titanate (LTO) calcined particles.
  • LTO lithium titanate
  • the specific surface area of the calcined body calculated by the BET method using nitrogen adsorption was 14.8 m 2 / g.
  • FIG. 13 shows a flow of preparation of lithium lanthanum titanate (LLTO) calcined particles.
  • LLTO lithium lanthanum titanate
  • Pre-baking treatment process The hydrothermally treated body obtained in the above step was placed in a firing boat made of alumina, and fired in air at 700 ° C. for 10 hours to obtain lithium lanthanum titanate (LLTO) calcined particles.
  • the specific surface area of the calcined body calculated by the BET method using nitrogen adsorption was 19.3 m 2 / g.
  • FIG. 14 shows a flow from pre-sintered sintered body particles to preparation of arrayed sintered bodies.
  • Paste preparation process Polyvinyl butyral was dissolved in a mixed solvent of toluene and 2-propanol to prepare a binder solution. Each paste was prepared by adding the above-mentioned lithium titanate (LTO) calcined particles or lithium lanthanum titanate (LLTO) calcined particles to the binder solution and kneading.
  • LTO lithium titanate
  • LLTO lithium lanthanum titanate
  • the obtained layer paste was applied onto a polyethylene terephthalate (PET) film by a doctor blade method, and dried at 120 ° C. for 10 minutes to prepare a layer green sheet.
  • PET polyethylene terephthalate
  • the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet produced by the above method were cut into a disk shape having a diameter of 12 mm.
  • Each layer green sheet obtained by cutting and peeling the PET film was alternately stacked, and both ends were made to be a lithium titanate layer green sheet.
  • the lithium titanate layer green sheets at both ends are held between peeled PET films, and after thermocompression bonding with a thermocompression bonding device at 80 ° C. for 30 minutes, the PET films of the uppermost layer and the lowermost layer are peeled off to obtain lithium titanate-titanate
  • a lithium lanthanum laminate was prepared. 51 sheets of lithium titanate layer green sheets and 50 sheets of lithium lanthanum titanate layer green sheets were used.
  • the average value of the width of each layer was 5.3 ⁇ m for lithium titanate and 3.7 ⁇ m for lithium lanthanum titanate (FIG. 16).
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged.
  • the thickness of the sintered body (that is, the thickness C of the composite electrode) was measured with a caliper and found to be 400 ⁇ m.
  • the actual density of the arrayed sintered body calculated by the dimension method is 2.53 g / cm 3 , the relative density is 61%, the porosity is 39%, and the arrayed sintered body calculated by the Archimedes method
  • the actual density was 3.05 g / cm 3 , the relative density was 73%, and the porosity was 27%.
  • the width X of the cut out array sintered body was 400 ⁇ m, and the depth Y was 4 mm.
  • the thickness C / width B was about 75, and the thickness C / width A was about 108.
  • Example 2 A laminated sintered body was produced in the same manner as in Example 1 except that the main sintering for producing the laminated sintered body in Example 1 was changed to 1150 ° C. for 5 hours and then to 850 ° C. for 12 hours.
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged.
  • the actual density of the arrayed sintered body calculated by the dimension method is 2.97 g / cm 3 , the relative density is 72%, the porosity is 28%, and the arrayed sintered body calculated by the Archimedes method
  • the actual density was 3.38 g / cm 3 , the relative density was 81%, and the porosity was 19%.
  • Example 3 A laminated sintered body was produced in the same manner as in Example 1 except that the main sintering for producing the sintered body in Example 1 was changed to 1150 ° C. for 5 hours.
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged. Further, the actual density of the arrayed sintered body calculated by the dimension method is 2.94 g / cm 3 , the relative density is 74%, the porosity is 24%, and the arrayed sintered body calculated by the Archimedes method The actual density was 3.15 g / cm 3 , the relative density was 79%, and the porosity was 21%.
  • Example 4 [Production of green sheet laminate]
  • the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet produced in Example 1 were cut into a disk shape having a diameter of 12 mm.
  • Each layer green sheet obtained by cutting and peeling the PET film was alternately stacked, and both ends were made to be a lithium titanate layer green sheet.
  • the lithium titanate layer green sheets at both ends were sandwiched by the peeled PET film, and thermocompression bonding was performed at 80 ° C. for 10 minutes using a thermocompression bonding apparatus.
  • As a thermocompression-bonded body 11 sheets of lithium titanate layer green sheets and 10 sheets of lithium lanthanum titanate layer green sheets were used.
  • thermocompression-bonded body Gold is vapor-deposited on one side of the obtained thermocompression-bonded body, five gold-deposited thermocompression-bonded bodies are stacked, a lithium titanate green sheet at both ends is sandwiched with a PET film, and thermocompression-bonded at 80 ° C. for 30 minutes with a thermocompression bonding device did.
  • a lithium titanate-lithium lanthanum titanate-gold laminate was produced by peeling the PET film of the top layer and the bottom layer.
  • the green sheet laminate prepared by the above method is sandwiched between alumina plates, and after removing polyvinyl butyral by preliminary baking in the atmosphere at 500 ° C. for 10 hours, air atmosphere atmosphere at 1150 ° C. for 5 hours and 850 ° C. for 12 hours
  • the laminated sintered body was produced by carrying out the main firing in this way.
  • a sintered body (400 ⁇ m thick) in which a lithium titanate layer, a lithium lanthanum titanate layer and a gold layer are arranged is produced by cutting out and processing the laminated sintered body produced by the above method using a grinder. did. Further, the actual density of the arrayed sintered body calculated by the dimension method is 2.92 g / cm 3 , the relative density is 60%, the porosity is 40%, and the arrayed sintered body calculated by the Archimedes method The actual density was 4.04 g / cm 3 , the relative density was 83%, and the porosity was 17%.
  • Example 5 [Preparation of lithium titanate layer and lithium lanthanum titanate layer green sheet] Polyvinyl butyral was dissolved in a mixed solvent of toluene and 2-propanol to prepare a binder solution. The lithium titanate (LTO) calcined particles produced in Example 1 or lithium lanthanum titanate (LLTO) calcined particles and acetylene black (AB) were mixed at a weight ratio of 95: 5 to prepare a mixed powder. Each paste was prepared by adding the mixed powder to the binder solution and kneading. Acetylene black is a type of carbon black.
  • LTO lithium titanate
  • LLTO lithium lanthanum titanate
  • AB acetylene black
  • the obtained layer paste was applied onto a polyethylene terephthalate (PET) film by a doctor blade method, and dried at 120 ° C. for 10 minutes to prepare a layer green sheet.
  • PET polyethylene terephthalate
  • a lithium titanate-lithium lanthanum titanate laminate was produced in the same manner as in Example 1 except that the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet produced by the above method were used.
  • Li 4 Ti 5 O 12 which is a lithium titanate having a spinel type crystal structure [ICDD No. 00-049-0207]
  • Rams Delight type Li 2 Ti 3 O 7 is a lithium titanate having a crystal structure [ICDD No. 00-034-0393, lithium titanate lanthanum having a perovskite crystal structure (LLTO) [ICDD No. 01-087-0935 Diffraction lines identified in [] were detected (FIG. 24).
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged.
  • the actual density of the arrayed sintered body calculated by the dimension method is 3.19 g / cm 3 , the relative density is 77%, the porosity is 23%, and the arrayed sintered body calculated by the Archimedes method
  • the actual density was 3.74 g / cm 3 , the relative density was 90%, and the porosity was 10%.
  • Example 6 Preparation of lithium lanthanum titanate green sheet
  • Polyvinyl butyral was dissolved in a mixed solvent of toluene and 2-propanol to prepare a binder solution.
  • the lithium lanthanum titanate (LLTO) calcined particles prepared in Example 1 and vapor grown carbon fiber (VGCF) were mixed at a weight ratio of 95: 5 to prepare a mixed powder.
  • the paste was prepared by adding the mixed powder to the binder solution and kneading.
  • the obtained paste was applied onto a polyethylene terephthalate (PET) film by a doctor blade method, and dried at 120 ° C. for 10 minutes to produce a green sheet.
  • PET polyethylene terephthalate
  • a lithium titanate-lithium lanthanum titanate laminate is prepared in the same manner as in Example 1 except that the lithium titanate layer green sheet produced in Example 1 and the lithium lanthanum titanate layer green sheet produced by the above method are used. Made.
  • a laminated sintered body was produced in the same manner as in Example 5 except that the green sheet laminate produced by the above method was used.
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged. Further, the actual density of the arrayed sintered body calculated by the dimension method is 3.01 g / cm 3 , the relative density is 73%, the porosity is 27%, and the arrayed sintered body calculated by the Archimedes method The actual density was 3.48 g / cm 3 , the relative density was 84%, and the porosity was 16%.
  • Example 7 (Coating process) The mixed powder paste of LTO and AB prepared in Example 5 and the mixed powder paste of LLTO and VGCF prepared in Example 6 are coated on a polyethylene terephthalate (PET) film by a doctor blade method, 120 ° C. The resultant was dried for 10 minutes to prepare a green sheet.
  • PET polyethylene terephthalate
  • a lithium titanate-lithium lanthanum titanate laminate was produced in the same manner as in Example 1 except that the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet produced by the above method were used. 61 sheets of lithium titanate layer green sheets and 60 sheets of lithium lanthanum titanate layer green sheets were used.
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged. Further, the actual density of the arrayed sintered body calculated by the dimension method is 3.03 g / cm 3 , the relative density is 76%, the porosity is 24%, and the arrayed sintered body calculated by the Archimedes method The actual density was 3.80 g / cm 3 , the relative density was 95%, and the porosity was 5%.
  • Example 8 [Production of green sheet laminate] Example except using the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet prepared in Example 7 and laminating so that the width after sintering is 10 ⁇ m or less in LTO and 5 ⁇ m or less in LLTO A lithium titanate-lithium lanthanum titanate laminate was prepared in the same manner as in (7).
  • a laminated sintered body was produced in the same manner as in Example 7 except that the green sheet laminate produced by the above method was used.
  • Li 4 Ti 5 O 12 which is a lithium titanate having a spinel type crystal structure [ICDD No. 00-049-0207]
  • Rams Delight type Li 2 Ti 3 O 7 is a lithium titanate having a crystal structure [ICDD No. 00-034-0393, lithium titanate lanthanum having a perovskite crystal structure (LLTO) [ICDD No. 01-087-0935 A diffraction line identified in [] was detected (FIG.
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged. Further, the actual density of the arrayed sintered body calculated by the dimension method is 2.77 g / cm 3 , the relative density is 70%, the porosity is 30%, and the arrayed sintered body calculated by the Archimedes method The actual density was 3.78 g / cm 3 , the relative density was 95%, and the porosity was 5%.
  • Example 9 [Production of green sheet laminate]
  • the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet prepared in Example 7 were laminated so that the width after sintering was 15 ⁇ m or less in LTO and 7.5 ⁇ m or less in LLTO
  • a lithium titanate-lithium lanthanum titanate laminate was produced in the same manner as in Example 7.
  • a laminated sintered body was produced in the same manner as in Example 7 except that the green sheet laminate produced by the above method was used.
  • Li 4 Ti 5 O 12 which is a lithium titanate having a spinel type crystal structure [ICDD No. 00-049-0207]
  • Rams Delight type Li 2 Ti 3 O 7 is a lithium titanate having a crystal structure [ICDD No. 00-034-0393, lithium titanate lanthanum having a perovskite crystal structure (LLTO) [ICDD No. 01-087-0935
  • LLTO lithium titanate lanthanum having a perovskite crystal structure
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged. Further, the actual density of the arrayed sintered body calculated by the dimension method is 3.06 g / cm 3 , the relative density is 77%, the porosity is 23%, and the arrayed sintered body calculated by the Archimedes method The actual density was 3.65 g / cm 3 , the relative density was 92%, and the porosity was 8%.
  • Example 10 [Production of green sheet laminate] Example except using the lithium titanate layer green sheet and the lithium lanthanum titanate layer green sheet prepared in Example 7 and laminating so that the width after sintering is 15 ⁇ m or more in LTO and 10 ⁇ m or less in LLTO A lithium titanate-lithium lanthanum titanate laminate was prepared in the same manner as in (7).
  • a laminated sintered body was produced in the same manner as in Example 7 except that the green sheet laminate produced by the above method was used.
  • Li 4 Ti 5 O 12 which is a lithium titanate having a spinel type crystal structure [ICDD No. 00-049-0207]
  • Rams Delight type Li 2 Ti 3 O 7 is a lithium titanate having a crystal structure [ICDD No. 00-034-0393, lithium titanate lanthanum having a perovskite crystal structure (LLTO) [ICDD No. 01-087-0935
  • LLTO lithium titanate lanthanum having a perovskite crystal structure
  • the laminated sintered body produced by the above method was cut out and processed using a grinder to produce a sintered body (400 ⁇ m in thickness) in which a lithium titanate layer and a lithium lanthanum titanate layer were arranged.
  • the actual density of the arrayed sintered body calculated by the dimension method is 3.00 g / cm 3 , the relative density is 75%, the porosity is 25%, and the arrayed sintered body calculated by the Archimedes method
  • the actual density was 3.63 g / cm 3 , the relative density was 91%, and the porosity was 9%.
  • Comparative Example 1 The lithium titanate layer green sheet produced in Example 1 was cut into a disc having a diameter of 12 mm. The green sheet from which the PET film was peeled off was overlapped, and the lithium titanate layer green sheet was sandwiched between the peeled PET film and thermocompression bonded by a thermocompression bonding apparatus at 80 ° C. for 30 minutes, then the PET film of the uppermost layer and the lowermost layer By peeling off, a laminate of lithium titanate layer green sheets was produced.
  • the green sheet laminate prepared by the above method is sandwiched between alumina plates, and after removing polyvinyl butyral by preliminary baking in the atmosphere at 500 ° C. for 10 hours, air atmosphere atmosphere at 1150 ° C. for 5 hours and 850 ° C. for 12 hours
  • the sintered body was produced by performing main firing in this way.
  • Comparative Example 2 A sintered body was produced in the same manner as in Comparative Example 1 except that the main sintering for producing the sintered body was changed to 1150 ° C. for 5 hours.
  • Comparative Example 3 [Preparation of calcined particles of lithium titanate (LTO) -lithium lanthanum titanate (LLTO) composite] (Coprecipitation process) A solution obtained by dissolving lanthanum chloride heptahydrate in water is mixed with an aqueous solution of titanium tetrachloride, and an aqueous solution containing 0.20 mmol / g of La, 3.10 mmol / g of Ti, and 8.67 mmol / g of Cl is prepared. Prepared. The aqueous solution was clear and did not form a precipitate upon standing at room temperature.
  • the obtained paste was applied onto a polyethylene terephthalate (PET) film by a doctor blade method, and dried at 120 ° C. for 10 minutes to prepare a composite green sheet.
  • PET polyethylene terephthalate
  • the composite green sheet produced above was cut into a disk shape having a diameter of 12 mm.
  • the composite green sheet obtained by cutting and peeling the PET film is overlapped, sandwiched by the peeled PET film, and thermocompression bonded by a thermocompression bonding device at 80 ° C. for 30 minutes, and then peeling the PET film of the uppermost layer and the lowermost layer A laminate of composite green sheets was produced.
  • the green sheet laminate prepared by the above method is sandwiched between alumina plates, and after removing polyvinyl butyral by preliminary baking in the atmosphere at 500 ° C. for 10 hours, air atmosphere atmosphere at 1150 ° C. for 5 hours and 850 ° C. for 12 hours
  • the sintered body was produced by performing main firing in this way.
  • Comparative Example 4 A sintered body was produced in the same manner as in Comparative Example 3, except that the main sintering for producing the sintered body was changed to 1150 ° C. for 5 hours.
  • the charge and discharge starts from the discharge, and performs a first discharge with a cut-off potential of 2.5 to 1.25 V at a constant current of 0.002 mA / cm 2 , and a discharge termination voltage of 1.25 V, and then a charge termination voltage of 1.
  • the initial discharge capacity and the initial charge capacity were converted to values per mass of the sintered body.
  • 36 and 37 show initial charge-discharge curves of Examples 1 to 4 at 90 ° C. and Comparative Examples 1 to 4
  • FIG. 38 shows initial charge-discharge curves of Examples 2 and 4 to 60 ° C.
  • FIG. The initial charge-discharge curves of Examples 7 to 10 at 60 ° C. are shown.
  • the coulombic efficiency was determined by dividing the initial charge capacity by the initial discharge capacity.
  • the sample in which LTO having a spinel structure was detected was an S-based sample
  • the sample in which Li 2 Ti 3 O 7 having a ramsdellite structure was detected was an R-based sample.
  • the width of each layer of the composite electrode of each example and the thickness of the electrode are shown in Table 1, and the charge / discharge test results (90 ° C.) of Examples 1, 2 and 4 of the S-based sample and the comparative example are shown in Table 2.
  • Table 3 shows the charge / discharge test results of Example 3 of the R-based sample and the comparative example
  • Table 4 shows the charge / discharge test results (60 ° C.) of Examples 2 and 4 to 10 of the S-based sample.
  • Example 1 and Comparative Example 1 are compared, the initial charge capacity and the Coulomb efficiency increased by using the arrayed sintered body as the positive electrode. This is considered to be because the lithium ion conduction path is in the positive electrode in Example 1 having a solid electrolyte layer, as compared with Comparative Example 1 in which the entire positive electrode is composed of lithium titanate.
  • Comparative Example 3 in which the whole of the positive electrode is composed of the LTO-LLTO complex is considered to be due to the formation of a lithium ion conduction path by LLTO in the positive electrode.
  • Comparative Example 3 is more excellent in initial discharge capacity and initial charge capacity. This is considered to be due to the fact that LLTO becomes a dense sintered body and lithium ion conductivity becomes high because Comparative Example 3 passes a high temperature of 1150 ° C. in the firing step.
  • Example 1 and Example 2 are compared.
  • a dense laminated sintered body can be obtained, and both the initial discharge capacity and the initial charge capacity are excellent.
  • LLTO forms a dense fixed electrolyte layer and a lithium ion conduction path with low resistance is formed, so that the result of the charge and discharge test is good. It is thought that it became.
  • Example 2 and Comparative Example 3 When Example 2 and Comparative Example 3 are compared, although the volume ratio of the solid electrolyte is lower in Example 2, the initial discharge capacity, the initial charge capacity, and the coulombic efficiency are excellent.
  • Example 2 and Comparative Example 3 have the same thermal history in the firing step, but the positive electrode of Example 2 is an array sintered body, and a plurality of solid electrolyte layers penetrating the positive electrode in parallel to the thickness direction of the positive electrode are ordered. In the positive electrode LTO-LLTO complex of Comparative Example 3 and the distribution of LLTO in the positive electrode is random, the lithium ion conductive path of Example 2 is higher Is considered to be formed more.
  • Example 2 and Example 4 When Example 2 and Example 4 are compared, the direction of Example 4 is excellent in first time discharge capacity, first time charge capacity, and coulombic efficiency.
  • Example 2 and Example 4 have the same heat history in the firing step, but in Example 4, a metal layer parallel to the thickness direction of the positive electrode is intentionally provided, and electron conduction is caused to LTO and LLTO. This is considered to be due to the fact that the electron conductivity of the positive electrode is higher than that of Example 2 which relies on it.
  • Example 3 and Comparative Example 2 are compared, the initial discharge capacity and the initial charge capacity were increased by using the array sintered body as the positive electrode. This is considered to be because the lithium ion conduction path is in the positive electrode in Example 3 having a solid electrolyte layer, as compared to Comparative Example 2 in which the entire positive electrode is composed of lithium titanate.
  • Comparative Example 4 in which the whole of the positive electrode is composed of the LTO-LLTO complex is considered to be because the lithium ion conduction path by LLTO is formed in the positive electrode.
  • Example 3 and Comparative Example 4 are compared, although the volume ratio of the solid electrolyte is lower in Example 3, the initial discharge capacity and the initial charge capacity are excellent.
  • Example 3 and Comparative Example 4 have the same thermal history in the firing step, but Example 3 is an arrayed sintered body, since a solid electrolyte layer parallel to the thickness direction of the positive electrode is intentionally provided. It is considered that this is because more lithium ion conduction paths are formed as compared with Comparative Example 4 in which the LLTO distribution is random.
  • Example 2 When Example 2 is compared with Examples 5 to 10, Examples 5 and 6 are more excellent in the initial discharge capacity, the initial charge capacity, and the coulombic efficiency.
  • Example 2 and Example 5 to 10 have the same heat history in the firing step, but in Example 5 to 10, acetylene black and vapor grown carbon fiber as a conductive additive are added, and LTO and LLTO are added. It is considered that the electron conductivity of the positive electrode is higher than that of Example 2 which relies on the electron conductivity.
  • Examples 7 and 8 are compared with Examples 9 and 10, Examples 7 and 8 are superior in initial discharge capacity and initial charge capacity. Further, from the charging curve, it can be understood that the overvoltage is lower in Examples 7 and 8.
  • Examples 7 to 10 have the same heat history in the firing step and the same additives (acetylene black and vapor grown carbon fiber), but Examples 7 and 8 have an LTO layer thickness of 10 ⁇ m or less, so It is considered that this is because the distance in which the lithium ions move in the LTO layer is shorter than in Examples 9 and 10, and the resistance is smaller.

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Abstract

La présente invention concerne une électrode qui contribue à la charge et à la décharge d'une grande quantité d'un matériau actif d'électrode contenu dans l'électrode, et présente une capacité plus proche de la capacité théorique que dans le passé, en réduisant un électrolyte solide qui ne contribue pas à la formation d'un trajet de conduction d'ions lithium. La présente invention concerne une électrode composite, l'électrode composite étant un compact fritté qui contient un matériau actif d'électrode et un électrolyte solide, l'électrode composite étant caractérisée en ce qu'elle est un réseau alterné dans lequel des couches de matériau actif d'électrode en forme de feuille contenant un matériau actif d'électrode de type oxyde et des couches d'électrolyte solide en forme de feuille contenant un électrolyte solide de type oxyde sont alignées en alternance, la largeur des couches de matériau actif d'électrode étant comprise entre 10 nm et 20 µm, la largeur des couches d'électrolyte solide étant comprise entre 10 nm et 20 µm et les couches d'électrolyte solide passant à travers l'électrode composite.
PCT/JP2018/038876 2017-10-20 2018-10-18 Électrode composite et batterie au lithium entièrement solide WO2019078307A1 (fr)

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WO2021029315A1 (fr) * 2019-08-09 2021-02-18 出光興産株式会社 Procédé de production d'électrolyte solide
WO2021085237A1 (fr) * 2019-10-29 2021-05-06 三井金属鉱業株式会社 Électrolyte solide au sulfure, et mélange d'électrodes, couche d'électrolyte solide et batterie solide l'utilisant
WO2021125344A1 (fr) * 2019-12-20 2021-06-24 Ｄｏｗａエレクトロニクス株式会社 Poudre d'oxyde conducteur d'ions lithium amorphe, son procédé de production, et procédé de production de poudre d'oxyde conducteur d'ions lithium ayant une structure cristalline nasicon
CN113991170A (zh) * 2021-10-15 2022-01-28 深圳大学 全固态电池
WO2024095670A1 (fr) * 2022-10-31 2024-05-10 パナソニックエナジー株式会社 Électrode positive pour batteries rechargeables et batterie rechargeable

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KR20220008056A (ko) * 2020-07-13 2022-01-20 주식회사 엘지에너지솔루션 저온 소결공정을 위한 산화물계 고체전해질을 포함하는 전고체전지 및 이의 제조방법
WO2023145783A1 (fr) * 2022-01-27 2023-08-03 日本碍子株式会社 Batterie secondaire au lithium
WO2023162454A1 (fr) * 2022-02-24 2023-08-31 日本碍子株式会社 Batterie secondaire au lithium

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CN113991170A (zh) * 2021-10-15 2022-01-28 深圳大学 全固态电池
CN113991170B (zh) * 2021-10-15 2023-09-05 深圳大学 全固态电池
WO2024095670A1 (fr) * 2022-10-31 2024-05-10 パナソニックエナジー株式会社 Électrode positive pour batteries rechargeables et batterie rechargeable

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