WO2017146105A1 - Laminate green sheet and continuous laminate green sheet, method for manufacturing same, and method for manufacturing all-solid-state secondary battery - Google Patents

Laminate green sheet and continuous laminate green sheet, method for manufacturing same, and method for manufacturing all-solid-state secondary battery Download PDF

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Publication number
WO2017146105A1
WO2017146105A1 PCT/JP2017/006630 JP2017006630W WO2017146105A1 WO 2017146105 A1 WO2017146105 A1 WO 2017146105A1 JP 2017006630 W JP2017006630 W JP 2017006630W WO 2017146105 A1 WO2017146105 A1 WO 2017146105A1
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Prior art keywords
green sheet
binder
electrode layer
layer green
solid electrolyte
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PCT/JP2017/006630
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French (fr)
Japanese (ja)
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晴菜 倉田
浩視 上田
幹裕 ▲高▼野
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凸版印刷株式会社
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Priority to JP2018501738A priority Critical patent/JPWO2017146105A1/en
Publication of WO2017146105A1 publication Critical patent/WO2017146105A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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 laminate green sheet, a continuous laminate green sheet, a production method thereof, and a production method of an all-solid-state secondary battery.
  • the most prominent secondary battery used in electronic devices is an all-solid lithium ion secondary battery (hereinafter, also referred to as an all-solid secondary battery) in which the entire structure of the negative electrode layer, the electrolyte layer, and the positive electrode layer is made of a solid material. ).
  • an all-solid secondary battery in which the entire structure of the negative electrode layer, the electrolyte layer, and the positive electrode layer is made of a solid material.
  • Patent Documents 1 to 3 disclose techniques related to the all-solid-state secondary battery.
  • JP 2000-340255 A Japanese Patent No. 4845244 Patent No. 5430930
  • Patent Document 1 when a laminated fired body including a positive electrode layer, a solid electrolyte layer, and a negative electrode layer is sandwiched between a positive electrode current collector and a negative electrode current collector, the positive electrode current collector and the positive electrode layer There is a problem that the interface resistance between the negative electrode current collector and the negative electrode layer is increased, and the battery performance may be deteriorated. Moreover, in order to produce an all-solid-state secondary battery, it is necessary to pass through a baking process twice, and there exists a subject that manufacturing efficiency may worsen.
  • Patent Document 3 a laminate in which a positive electrode current collector green sheet, a positive electrode layer green sheet, a solid electrolyte layer green sheet, a negative electrode layer green sheet, and a negative electrode current collector green sheet are laminated.
  • the interface resistance between the positive electrode current collector and the positive electrode layer and between the negative electrode current collector and the negative electrode layer is considered to be reduced.
  • the positive electrode layer green sheet and the negative electrode layer green sheet are printed on both sides of the solid electrolyte layer green sheet, and the metal foil current collector paste is printed on the upper layer, which may make the manufacturing method complicated. There is a problem.
  • the present invention has been made in view of these points, and an object thereof is to provide an all-solid-state secondary battery having high battery performance by a simple manufacturing process.
  • the present invention also provides a laminate green sheet and a continuous laminate green sheet used for obtaining an all-solid secondary battery having high battery performance by a simple production process, a method for producing the same, and production of an all-solid secondary battery. It aims to provide a method.
  • a laminate green sheet according to an aspect of the present invention is provided with a metal foil current collector, and a first electrode layer green sheet provided on the metal foil current collector and including a first binder.
  • the ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, and the ease of decomposition of the third binder is It is larger than the easiness of decomposition of the first binder and equal to or easier than the easiness of decomposition of the second binder.
  • the continuous laminated body green sheet which concerns on 1 aspect of this invention is provided on the said metal foil electrical power collector, the said metal foil electrical power collector, the 1st electrode layer green sheet containing a 1st binder, and the said 1st A laminate green comprising: a solid electrolyte layer green sheet including a second binder provided on an electrode layer green sheet; and a second electrode layer green sheet including a third binder provided on the solid electrolyte layer green sheet. Sheets are continuously laminated, and the ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, and the third binder is decomposed. The ease is greater than the ease of decomposing the first binder, and is equal to the ease of decomposing the second binder, or the easiness of decomposing the second binder. It is larger than is.
  • the method for producing a laminate green sheet according to an aspect of the present invention includes applying a first electrode slurry containing a first binder on a metal foil current collector or printing and then drying the first electrode layer green.
  • a first electrode layer green sheet forming step for forming a sheet, and a solid electrolyte slurry containing a second binder is applied or printed on the first electrode layer green sheet and then dried to form a solid electrolyte layer green sheet.
  • the ease of decomposing the third binder is greater than the easiness of decomposing the first binder, and the easiness of decomposing the first binder is greater than the decomposability of the second binder, or It is characterized by greater than ease of disassembly.
  • the method for producing a continuous laminate green sheet includes applying a first electrode slurry containing a first binder onto a metal foil current collector or printing and then drying the first electrode layer.
  • a first electrode layer green sheet forming step for forming a green sheet, and a solid electrolyte slurry containing a second binder is applied or printed on the first electrode layer green sheet and then dried to form a solid electrolyte layer green sheet
  • And forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying the slurry.
  • Layer green sheet forming step, the metal foil current collector, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second electrode A green sheet laminating step of continuously laminating a plurality of laminated green sheets in which layer green sheets are sequentially laminated, and the ease of decomposing the second binder is equal to the ease of decomposing the first binder Or the easiness of decomposition of the first binder, the easiness of decomposition of the third binder is greater than the easiness of decomposition of the first binder and the same as the easiness of decomposition of the second binder, or It is larger than the ease of decomposition of the second binder.
  • the first electrode slurry containing the first binder is applied or printed on the first metal foil current collector and then dried.
  • a second electrode layer green sheet formed by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying to form a second electrode layer green sheet
  • a method for producing an all-solid-state secondary battery wherein a first electrode slurry containing a first binder is applied or printed on a first metal foil current collector and then dried.
  • the ease of decomposing the third binder is equal to or greater than the ease of decomposing the first binder. Greater than the decomposition ease of loaders, and being greater than the decomposition ease of decomposition ease equal to or said second binder of said second binder.
  • the present invention it is possible to provide an all solid state secondary battery having high battery performance with a simple manufacturing process. Moreover, according to this invention, the laminated body green sheet used in order to obtain the above all-solid-state secondary battery and a continuous laminated body green sheet can be obtained. Furthermore, according to this invention, the manufacturing method of the laminated body green sheet, the continuous laminated body green sheet, and an all-solid-state secondary battery for obtaining an all-solid-state secondary battery with high battery performance easily can be obtained.
  • FIG. 1 is a cross-sectional view of an all solid state secondary battery described in the first embodiment.
  • the all-solid-state secondary battery 1 in the first embodiment includes a positive electrode current collector 11 made of a metal foil current collector (first metal foil current collector), and a positive electrode current collector 11.
  • this configuration is such that at least the positive electrode current collector 11 and the negative electrode current collector 15 are formed on a laminate green sheet in which a positive electrode layer green sheet 12a, a solid electrolyte layer green sheet 13a, and a negative electrode layer green sheet 14a are stacked.
  • This is realized by the manufacturing method of the all-solid-state secondary battery 1 in which batch firing is performed in a state where the is bonded.
  • the solid electrolyte layer 13 includes at least one of a solid electrolyte and glass that becomes a solid electrolyte after firing.
  • the solid electrolyte contained in the solid electrolyte layer 13 and the glass that becomes the solid electrolyte after firing are not particularly limited as long as the material has low electron conductivity and high lithium ion conductivity.
  • an oxide solid electrolyte or An amorphous body (glass body), crystal body, glass ceramic, or the like of a sulfide-based solid electrolyte is used.
  • an oxide-based solid electrolyte that can be fired at a high temperature is preferable.
  • a NASICON (Na super ionic conductor) type oxide, a perovskite type oxide, a LISICON (Lithium super ionic conductor) type oxide, a garnet type oxide, an oxide glass Etc. are preferably used.
  • the oxide-based solid electrolyte that can be fired at such a high temperature include Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 0.29 La 0.571 TiO 3 , Li 4 SiO 4 —Li 3 PO 4 , Li 3 BO 3 —Li 3 PO 4 , Li 7 La 3 Zr 2 O 12 , Li 3.4 V 0 .6 Si 0.4 O 4 or the like can be used.
  • the thickness of the solid electrolyte layer 13 is preferably in the range of 1 ⁇ m to 500 ⁇ m.
  • the thickness of the solid electrolyte layer 13 is thinner than 1 ⁇ m, the positive electrode layer 12 and the negative electrode layer 14 are easily short-circuited, and not only the performance of the all-solid-state secondary battery 1 may be reduced but also the safety may be reduced. There is.
  • the thickness of the solid electrolyte layer 13 is thicker than 500 ⁇ m, the movement of conductive ions such as lithium ions in the solid electrolyte layer 13 is likely to be inhibited, and the output of the all-solid secondary battery 1 may be lowered. .
  • the positive electrode layer 12 includes a positive electrode active material and at least one of a solid electrolyte and a glass that becomes a solid electrolyte after firing.
  • the positive electrode active material contained in the positive electrode layer 12 may be any material that can occlude and release lithium ions, and is not particularly limited.
  • the positive electrode layer 12 contains, as a positive electrode active material, an active material that exhibits a higher potential than the active material contained in the negative electrode layer 14.
  • lithium nickel cobalt manganese oxide LiNi x Co 1-y- x Mn y O 2
  • lithium cobalt oxide LiCoO 2
  • lithium nickelate LiNiO 2
  • lithium manganate LiMn 2 Li transition such as O 4
  • lithium iron phosphate LiFePO 4
  • lithium cobalt phosphate LiCoPO 4
  • lithium manganese phosphate LiMnPO 4
  • lithium vanadium phosphate Li 3 V 2 (PO 4 ) 3
  • Metal compounds can be used as the solid electrolyte contained in the positive electrode layer 12
  • the same material as the solid electrolyte contained in the solid electrolyte layer 13 can be used as the solid electrolyte contained in the solid electrolyte layer 13 can be used.
  • Two or more solid electrolytes contained in the positive electrode layer 12 may be mixed and used. Further, the solid electrolyte contained in the positive electrode layer 12 may be the same as or different from the solid electrolyte contained in the solid electrolyte layer 13 and the negative electrode layer 14 described later.
  • the positive electrode layer 12 may contain a conductive additive.
  • the conductive auxiliary agent is not particularly limited as long as it has conductivity.
  • a conductive carbon material particularly carbon black, activated carbon, carbon carbon fiber, or the like can be used.
  • the content of the conductive additive in the positive electrode layer 12 is preferably in the range of more than 0% and less than 90% by weight with respect to the weight of the positive electrode active material. This is because if the content of the conductive auxiliary is 90% by weight or more, the amount of the positive electrode active material in the positive electrode layer 12 may be insufficient and the lithium storage capacity may be reduced.
  • the positive electrode layer 12 can be selected to have an arbitrary thickness according to a desired battery capacity.
  • the negative electrode layer 14 includes a negative electrode active material and at least one of a solid electrolyte and glass that becomes a solid electrolyte after firing.
  • the negative electrode active material included in the negative electrode layer 14 may be any material that can occlude and release lithium ions, and is not particularly limited.
  • the negative electrode layer 14 contains, as a negative electrode active material, an active material that shows a lower potential than the active material contained in the positive electrode layer 12.
  • the negative electrode active material examples include carbon materials such as hard carbon, soft carbon, and graphite, alloy materials such as Sn-based alloys and Si-based alloys, nitrides such as LiCoN, and lithium titanate (Li 4 Ti 5 O 12 ). Lithium transition metal oxides such as lithium vanadium phosphate (Li 3 V 2 (PO 4 ) 3 ) can be used. Moreover, you may use metal lithium foil as a negative electrode active material.
  • the solid electrolyte contained in the negative electrode layer 14 the same material as the solid electrolyte contained in the solid electrolyte layer 13 and the positive electrode layer 12 can be used. Two or more kinds of solid electrolytes contained in the negative electrode layer 14 may be mixed and used. Further, the solid electrolyte contained in the negative electrode layer 14 may be the same as or different from the solid electrolyte contained in the solid electrolyte layer 13 and the positive electrode layer 12.
  • the negative electrode layer 14 may contain a conductive additive.
  • the conductive auxiliary agent is not particularly limited as long as it has conductivity similar to the conductive auxiliary agent contained in the positive electrode layer 12.
  • a conductive carbon material particularly carbon black, activated carbon, carbon carbon fiber, or the like is used. be able to.
  • the content of the conductive additive in the negative electrode layer 14 is preferably in the range of more than 0% and less than 90% by weight with respect to the weight of the negative electrode active material. This is because when the content of the conductive auxiliary is 90% by weight or more, the amount of the negative electrode active material in the negative electrode layer 14 is insufficient, and the lithium storage capacity may be reduced.
  • the negative electrode layer 14 can be selected to have an arbitrary thickness according to a desired battery capacity.
  • the positive electrode current collector 11 provided in close contact with the positive electrode layer 12 and the negative electrode current collector 15 provided in close contact with the negative electrode layer 14 are each made of a metal foil current collector.
  • the electric conductor 15 may be described as “metal foil current collector”.
  • the material of the metal foil current collector is not particularly limited as long as it is a conductive material. For example, metal materials such as stainless steel, nickel, aluminum, iron, titanium, copper, palladium, gold, and platinum are used. Can do.
  • the material of the metal foil current collector is preferably selected in consideration of not being melted and decomposed under the firing conditions described later, and the battery operating potential and conductivity of the metal foil current collector.
  • the thickness of the metal foil current collector is preferably in the range of 3 ⁇ m to 50 ⁇ m.
  • the thickness of the metal foil current collector is in the range of 3 ⁇ m or more and 50 ⁇ m or less, the metal foil current collector is not easily cracked during the production of the laminated fired body, and sufficiently supports the laminated green sheet 10 Thickness to be obtained.
  • FIG. 2 is a cross-sectional view of the laminate green sheet 10 used in the first embodiment.
  • the laminate green sheet 10 in the first embodiment includes a positive electrode current collector 11 made of a metal foil current collector, and a positive electrode layer green sheet 12a provided on the positive electrode current collector 11.
  • the solid electrolyte layer green sheet 13a provided on the positive electrode layer green sheet 12a and the negative electrode layer green sheet 14a provided on the solid electrolyte layer green sheet 13a are provided.
  • the binder contained in each of the positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a is a binder that is more easily decomposed in a layer farther than the positive electrode current collector 11 of the laminate green sheet 10.
  • the laminate green sheet 10 is formed so as to include a binder that is more easily decomposed in layers farther from the positive electrode current collector 11.
  • each green sheet will be described.
  • Solid electrolyte layer green sheet The solid electrolyte layer green sheet 13a is coated or printed on a positive electrode layer green sheet 12a or a negative electrode layer green sheet 14a, which will be described later, and a solid electrolyte slurry in which a binder made of a solid electrolyte and an organic resin is dispersed in a solvent, and then dried. Is formed.
  • the method for preparing the solid electrolyte slurry is not particularly limited.
  • the solid electrolyte layer 13 is obtained by firing the solid electrolyte layer green sheet 13a.
  • a positive electrode slurry in which a binder made of a positive electrode active material, a solid electrolyte, and an organic substance is dispersed in a solvent is placed on the positive electrode current collector 11 made of a metal foil current collector or the solid electrolyte layer green sheet 13a. It is formed by coating or printing and drying.
  • the method for preparing the positive electrode slurry is not particularly limited.
  • the positive electrode layer 12 is obtained by firing the positive electrode layer green sheet 12a.
  • Negative electrode layer green sheet In the negative electrode layer green sheet 14a, a negative electrode slurry in which a binder made of a negative electrode active material, a solid electrolyte and an organic substance is dispersed in a solvent is formed on the negative electrode current collector 15 made of a metal foil current collector or the solid electrolyte layer green sheet 13a. It is formed by coating or printing and drying. The method for preparing the negative electrode slurry is not particularly limited. The negative electrode layer green sheet 14a is fired, whereby the negative electrode layer 14 is obtained.
  • the metal foil current collector is the positive electrode current collector 11 provided in close contact with the positive electrode layer green sheet 12a or the negative electrode current collector 15 provided in close contact with the negative electrode layer green sheet 14a when the laminate green sheet 10 is manufactured.
  • the positive electrode current collector 11 and the negative electrode current collector 15 are the positive electrode current collector 11 and the negative electrode current collector 15 used in the all solid state secondary battery 1.
  • the laminate green sheet 10 includes a metal foil current collector, a first electrode layer green sheet provided on the metal foil current collector, and a solid electrolyte layer green sheet provided on the first electrode layer green sheet. And a second electrode layer green sheet provided on the solid electrolyte layer green sheet. Therefore, in addition to the configuration shown in FIG. 2, the laminate green sheet 10 includes a negative electrode current collector 15 made of a metal foil current collector, a negative electrode layer green sheet 14a provided on the negative electrode current collector 15, The structure provided with the solid electrolyte layer green sheet 13a provided on the negative electrode layer green sheet 14a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be sufficient. In this case, each layer is formed so as to include a binder that is more easily decomposed as the layer farther from the negative electrode current collector 15 of the multilayer green sheet 10.
  • the solid electrolyte layer green sheet 13a is formed by applying or printing a solid electrolyte slurry formed by mixing a solid electrolyte and an organic substance binder together with a solvent, and then drying.
  • the solid electrolyte slurry is applied on, for example, a positive electrode layer green sheet 12a or a negative electrode layer green sheet 14a described later.
  • the method for preparing the solid electrolyte slurry is not particularly limited.
  • the positive electrode layer green sheet 12 a is formed by mixing a positive electrode active material, a solid electrolyte, and an organic substance binder together with a solvent and applying or printing a positive electrode slurry, followed by drying.
  • the positive electrode slurry is applied on the positive electrode current collector 11 or a solid electrolyte layer green sheet 13a described later.
  • the method for preparing the positive electrode slurry is not particularly limited.
  • the negative electrode layer green sheet 14a is formed by mixing a negative electrode active material, a solid electrolyte, and an organic substance binder together with a solvent and applying or printing a negative electrode slurry, followed by drying.
  • the negative electrode slurry is applied on the negative electrode current collector 15 or a solid electrolyte layer green sheet 13a described later.
  • the method for preparing the negative electrode slurry is not particularly limited.
  • the thermal weight reduction peak temperature is used.
  • the following conditions are satisfied. That is, in the laminate green sheet, the binder contained in the first electrode layer green sheet provided on the current collector is the first binder, and the binder contained in the solid electrolyte layer green sheet provided on the first electrode layer green sheet. Is the second binder, and the binder contained in the second electrode layer green sheet provided on the solid electrolyte layer green sheet is the third binder.
  • the ease of decomposition of the second binder is as follows: (Ii) The ease of decomposing the third binder is greater than the easiness of decomposing the first binder and the decomposing of the second binder. It is equal to the ease or greater than the ease of decomposing the second binder.
  • thermogravimetric decrease peak temperature (Tse) of the first binder the thermogravimetric decrease peak temperature (Tse) of the second binder, and the thermogravimetric decrease peak temperature (Tb) of the third binder are: It is more preferable to satisfy both the following formulas (1) and (2).
  • the first electrode layer green sheet and the second electrode layer green sheet when the first electrode layer green sheet is the positive electrode layer green sheet 12a, the second electrode layer green sheet is the negative electrode layer green sheet 14a.
  • the first electrode layer green sheet is the negative electrode layer green sheet 14a, the second electrode layer green sheet is the positive electrode layer green sheet 12a.
  • a firing process in which the temperature is raised to the sintering temperature of the particles in one step can shorten the production time and reduce the production cost, but in such a firing process, a large amount of binder decomposition gas is generated at one time. .
  • the gas generated by the decomposition of the first binder is converted into the solid electrolyte layer green sheet or the second electrode layer. May affect green sheets.
  • the binder is decomposed first from the layer far from the current collector, so that the electrolyte layer or the solid electrolyte layer is formed from the layer far from the current collector.
  • binder for example, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinylidene fluoride, polytetrafluoroethylene, ethyl cellulose, acrylic resin, and the like can be used.
  • each binder is preferably included in the range of 3 wt% to 40 wt%, and is preferably 3 wt% to 25 wt%. It is more preferable to be within the range. That is, the binder content relative to the entire solid content excluding the solvent from each slurry is preferably in the range of 3 wt% to 40 wt%, and preferably in the range of 3 wt% to 25 wt%. More preferred. When the binder content is less than 3% by weight, for example, active materials or solid electrolytes may not be sufficiently bound. On the other hand, when the content of the binder is larger than 40% by weight, the battery capacity per volume decreases.
  • the positive electrode layer green sheet 12a, the negative electrode layer green sheet 14a, and the solid electrolyte layer green sheet 13a may contain a firing aid that promotes formation of a matrix structure in each green sheet during firing and lowers the firing temperature.
  • the firing aid is not particularly limited as long as it does not react with the positive electrode active material, the negative electrode active material, and the solid electrolyte, and the softening point temperature is lower than the fusion temperature of the positive electrode active material, the negative electrode active material, and the solid electrolyte. Can be used.
  • the firing aid may be a material having lithium ion conductivity or a material having no lithium ion conductivity, but a material having lithium ion conductivity is preferable.
  • the content of the firing aid having no lithium ion conductivity is preferably 5% by weight or less, more preferably 3% by weight or less, based on the weight of the solid electrolyte contained in each green sheet.
  • the content of the sintering aid having lithium ion conductivity is preferably included within a range of 50% by weight or less with respect to the weight of the solid electrolyte contained in each green sheet. If the firing aid is excessively contained, the lithium ion conductivity in the laminated fired body obtained by firing each green sheet is lowered, and the battery performance may be lowered.
  • the solvent used in the positive electrode slurry, the negative electrode slurry, and the solid electrolyte slurry is not particularly limited as long as the above-described binder can be dissolved.
  • alcohols such as ethanol, isopropanol, and n-butanol, toluene, terpineol, and acetic acid.
  • the positive electrode slurry and the negative electrode slurry can be prepared by mixing the above-described positive electrode active material or negative electrode active material, solid electrolyte, binder, conductive auxiliary agent, baking auxiliary agent, and the like with a solvent.
  • the slurry for solid electrolyte can be produced by mixing the solid electrolyte, the binder, the conductive aid, the firing aid and the like described above with a solvent.
  • the method for mixing the slurry is not particularly limited, and additives such as thickeners, plasticizers, antifoaming agents, leveling agents, and adhesion imparting agents may be added as necessary.
  • coating and printing methods for positive electrode slurry, negative electrode slurry, and solid electrolyte slurry include a doctor blade method, a calendar method, a spin coating method, a dip coating method, an ink jet method, an offset method, a die coating method, and a spray. Method, screen printing method and the like.
  • the drying method of the slurry for positive electrodes, the slurry for negative electrodes, and the slurry for solid electrolytes is not specifically limited, For example, heat drying, reduced pressure drying, heating reduced pressure drying, etc. can be used.
  • the drying atmosphere is not particularly limited, and can be performed, for example, in an air atmosphere or an inert atmosphere (a nitrogen atmosphere or an argon atmosphere).
  • the positive electrode layer green sheet, the solid electrolyte layer green sheet, and the negative electrode layer green sheet constitute a laminated green sheet that is sequentially laminated.
  • the all-solid-state secondary battery 1 of the present embodiment is formed by firing the laminated green sheet 10 at once. That is, the manufacturing method of the all-solid-state secondary battery 1 of this embodiment includes a positive electrode layer green sheet forming step of forming the positive electrode layer green sheet 12a on the positive electrode current collector 11, and a solid electrolyte layer on the positive electrode layer green sheet 12a.
  • the laminate green sheet 10 is generated including a solid electrolyte layer green sheet forming step for forming the green sheet 13a and a negative electrode layer green sheet forming step for forming the negative electrode green sheet 14a on the solid electrolyte layer green sheet 13a.
  • a laminate green sheet forming step is provided.
  • the manufacturing method of the all-solid-state secondary battery 1 of this embodiment is the negative electrode which consists of a metal foil collector on the negative electrode layer green sheet 14a exposed on the surface of the laminated body green sheet 10, as shown in FIG. A negative electrode current collector bonding step of bonding the current collector 15; and a baking step of baking the multilayer body 1a including the multilayer green sheet 10 and the negative electrode current collector 15.
  • the heating temperature in the firing step is a temperature equal to or higher than the thermal decomposition temperature of the binder contained in the laminate green sheet 10 and lower than the oxidation temperature of the positive electrode active material and the negative electrode active material or lower than the combustion temperature of the metal foil current collector. Is preferred. Specifically, the heating temperature is preferably in the range of 300 ° C. to 1100 ° C., more preferably in the range of 300 ° C. to 900 ° C. When the heating temperature is lower than 300 ° C., the binder does not completely burn out in the baking step and becomes a residue, which may hinder electronic conduction or ionic conduction.
  • the heating temperature is higher than 1100 ° C.
  • the positive electrode active material, the negative electrode active material, and the solid electrolyte may be melted / altered to deteriorate the battery performance.
  • the atmosphere in the firing step is not particularly limited, and can be performed, for example, in an air atmosphere or an inert atmosphere (a nitrogen atmosphere or an argon atmosphere).
  • an inert atmosphere a nitrogen atmosphere or an argon atmosphere.
  • the firing time in the firing step is not particularly limited as long as the binder used is sufficiently decomposed.
  • the all-solid-state secondary battery 1 of the present embodiment is formed on the positive electrode layer green sheet 12a or the negative electrode layer green sheet 14a formed at the position farthest from the metal foil current collector of the laminate green sheet 10.
  • the laminated body 1a bonded with the metal foil current collector can be formed by batch firing. That is, as shown in FIG. 2, when the laminate green sheet 10 includes the positive electrode current collector 11, the negative electrode current collector is disposed on the negative electrode layer green sheet 14 a formed farthest from the positive electrode current collector 11.
  • the all-solid-state secondary battery 1 is obtained by laminating 15 and firing together.
  • the method for attaching the metal foil current collector is not particularly limited, and for example, a flat plate press, a roll press, a hot press, a cold isostatic press, a hot isostatic press, or the like can be used.
  • the laminate green sheet 10 is provided on the metal foil current collector, the first electrode layer green sheet provided on the metal foil current collector, and the first electrode layer green sheet.
  • the solid electrolyte layer green sheet and the second electrode layer green sheet provided on the solid electrolyte layer green sheet may be provided. Therefore, the laminate green sheet 10 is provided on the negative electrode current collector 15, the negative electrode layer green sheet 14a provided on the negative electrode current collector 15, and the negative electrode layer green sheet 14a in addition to the configuration described above.
  • the solid electrolyte layer green sheet 13a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be used.
  • a negative electrode slurry containing a negative electrode active material is applied or printed on the negative electrode current collector 15 and then dried to form a negative electrode layer green sheet 14a.
  • a solid containing a solid electrolyte material on the negative electrode layer green sheet 14a The electrolyte slurry is applied or printed and then dried to form the solid electrolyte layer green sheet 13a.
  • the positive electrode slurry containing the positive electrode active material is applied or printed on the solid electrolyte layer green sheet 13a and then dried to form the positive electrode layer green.
  • the laminated body green sheet 10 is formed by forming the sheet 12a.
  • disassembly of the binder contained in the solid electrolyte layer green sheet 13a is equal to the ease of decomposition
  • the easiness of decomposition of the binder contained in the positive electrode layer green sheet 12a is greater than the easiness of decomposition of the binder contained in the negative electrode layer green sheet 14a, and the easiness of decomposition of the binder contained in the solid electrolyte layer green sheet 13a. Or greater than the ease of decomposition of the binder contained in the solid electrolyte layer green sheet 13a.
  • the all-solid-state secondary battery 1 is obtained by baking the laminated body which bonded the positive electrode electrical power collector 11 on the positive electrode layer green sheet 12a exposed on the surface of the laminated body green sheet produced as mentioned above. It is done.
  • Second Embodiment In the second embodiment, a stacked-type all-solid secondary battery (series all-solid secondary battery) and an all-solid secondary battery manufacturing method according to the present invention will be described. Moreover, in the following 2nd Embodiment, the manufacturing method of the continuous laminated body green sheet used for manufacture of the all-solid-state secondary battery which concerns on this invention, and a continuous laminated body green sheet is demonstrated. Moreover, when the all-solid-state secondary battery of 2nd Embodiment has the structure similar to the all-solid-state secondary battery 1 demonstrated in 1st Embodiment, it demonstrates using a common referential mark.
  • a series all solid state secondary battery (hereinafter referred to as an all solid state secondary battery) 21 in the second embodiment includes a positive electrode layer 12 and a solid electrolyte layer 13 provided on the positive electrode layer 12. , And a negative electrode layer 14 provided on the solid electrolyte layer 13.
  • the all-solid-state secondary battery 21 is in close contact with the positive electrode layer 12 or the negative electrode layer 14 between the stacked electrode stacks 20 and on the outer side in the stacking direction of the stacked electrode stacks 20. And provided with a plurality of metal foil current collectors (positive electrode current collector 11 or negative electrode current collector 15).
  • a plurality of stacked green sheets each including a positive electrode layer green sheet 12a, a solid electrolyte layer green sheet 13a, and a negative electrode layer green sheet 14a are stacked via the positive electrode current collector 11, This is realized by the manufacturing method of the all-solid-state secondary battery 21 in which batch firing is performed with the outer surface sandwiched between the positive electrode current collector 11 and the negative electrode current collector 15.
  • the positive electrode layer 12, the solid electrolyte layer 13 and the negative electrode layer 14, and the positive electrode current collector 11 or the negative electrode current collector 15 are the positive electrode layer 12, the solid electrolyte layer 13 and the negative electrode layer 14, and the positive electrode current collector of the first embodiment. Since it is the same as that of the body 11 or the negative electrode current collector 15, the description thereof is omitted.
  • the continuous laminate green sheet 30 in the second embodiment includes a positive electrode current collector 11 made of a metal foil current collector, and a positive electrode layer green sheet 12 a provided on the positive electrode current collector 11.
  • a laminated green sheet 10 (10a to 10e) comprising: a solid electrolyte layer green sheet 13a provided on the positive electrode layer green sheet 12a; and a negative electrode layer green sheet 14a provided on the solid electrolyte layer green sheet 13a. are continuously laminated.
  • the positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a are the positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a of the multilayer green sheet 10 of the first embodiment. Since it is the same as that of FIG. Moreover, since the binder contained in each layer is the same as the binder described in the first embodiment, the description thereof is omitted.
  • the method for producing the continuous laminate green sheet 30 is to apply or print a positive electrode slurry containing a positive electrode active material on the positive electrode current collector 11 made of a metal foil current collector, and then dry to form the positive electrode layer green sheet 12a.
  • the manufacturing method of the continuous laminate green sheet 30 includes a green sheet lamination step of continuously laminating a plurality of laminate green sheets 10 (10a to 10e).
  • the continuous laminate green sheet 30 is, for example, the positive electrode current collector 11 side of one laminate green sheet 10 (eg, laminate green sheet 10b) among the plurality of laminate green sheets 10 (10a to 10e) and the other.
  • the laminated green sheet 10 (for example, the laminated green sheet 10a) is bonded to the negative electrode layer green sheet 14a so as to be adjacent to each other.
  • the method for laminating the laminate green sheets 10 is not particularly limited, and for example, a flat plate press, a roll press, a hot press, a cold isostatic press, a hot isostatic press, or the like can be used.
  • the all-solid-state secondary battery 21 of the second embodiment is formed by degreasing the binder from the continuous laminate green sheet 30 and firing it. That is, the manufacturing method of the all-solid-state secondary battery 21 of the present embodiment is such that a positive electrode slurry containing a positive electrode active material is applied or printed on a positive electrode current collector 11 made of a metal foil current collector, and then dried.
  • a laminate green sheet forming step for forming the laminate green sheet 10 (10a to 10e) is provided.
  • the method for manufacturing the all-solid-state secondary battery 21 of the present embodiment includes a continuous laminate green sheet forming step in which a plurality of laminate green sheets 10 (10a to 10e) are laminated to form a continuous laminate green sheet 30; As shown in FIG. 6, a negative electrode current collector bonding step of bonding a negative electrode current collector 15 made of a metal foil current collector on the negative electrode layer green sheet 14 a exposed on the surface of the continuous laminate green sheet 30; And a firing step of firing the laminate 21 a including the continuous laminate green sheet 30 and the negative electrode current collector 15.
  • the heating temperature in the firing step of the second embodiment, the method for attaching the metal foil current collector, and the like are the same as those of the first embodiment, and thus the description thereof is omitted.
  • the all-solid-state secondary battery 21 of the second embodiment includes the electrode layer green sheet (positive electrode layer green sheet 12a) formed at the position farthest from the metal foil current collector of the continuous laminate green sheet 30.
  • the laminated body 21a which bonded the metal foil electrical power collector on the negative electrode layer green sheet 14a) can be formed by baking collectively. That is, when the continuous laminate green sheet 30 includes the positive electrode current collector 11, the negative electrode current collector 15 is bonded together on the negative electrode layer green sheet 14 a formed farthest from the positive electrode current collector 11.
  • the all-solid-state secondary battery 21 is obtained.
  • the laminate green sheet 10 includes a metal foil current collector, and a first electrode layer green sheet provided on the metal foil current collector.
  • the solid electrolyte layer green sheet provided on the first electrode layer green sheet and the second electrode layer green sheet provided on the solid electrolyte layer green sheet may be provided at least. Therefore, the laminate green sheet 10 is provided on the negative electrode current collector 15, the negative electrode layer green sheet 14a provided on the negative electrode current collector 15, and the negative electrode layer green sheet 14a in addition to the configuration described above.
  • the solid electrolyte layer green sheet 13a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be used.
  • a negative electrode slurry containing a negative electrode active material is applied or printed on the negative electrode current collector 15 and then dried to form a negative electrode layer green sheet 14a.
  • a solid containing a solid electrolyte material on the negative electrode layer green sheet 14a The electrolyte slurry is applied or printed and then dried to form the solid electrolyte layer green sheet 13a.
  • the positive electrode slurry containing the positive electrode active material is applied or printed on the solid electrolyte layer green sheet 13a and then dried to form the positive electrode layer green.
  • a sheet green is formed by forming the sheet 12a.
  • the all-solid-state secondary battery 21 is formed by continuously laminating the laminated green sheets produced as described above, and the positive electrode current collector on the positive electrode layer green sheet 12a exposed on the surface of the continuous laminated green sheet. 11 is obtained by firing the laminated body to which 11 is bonded.
  • thermogravimetric decrease peak temperature each binder (polyvinyl butyral (PVB) resin, acrylic resin) used for each of the first active material layer, the solid electrolyte layer, and the second active material layer of the laminate green sheet of each of the following Examples and Comparative Examples
  • the thermogravimetric decrease peak temperatures of A and acrylic resin B) were measured.
  • the thermogravimetric decrease peak temperature was measured by using a thermogravimetric measuring device and raising the temperature from room temperature to 700 ° C. at a rate of temperature rise of 100 ° C./min in a nitrogen stream.
  • the thermogravimetric decrease peak temperature of the polyvinyl butyral (PVB) resin was 400 ° C.
  • thermogravimetric decrease peak temperature of the acrylic resin A was 380 ° C.
  • thermogravimetric decrease peak temperature of the acrylic resin B was 330 ° C.
  • Example 1 [Slurry preparation process] ⁇ Preparation of slurry for positive electrode> 50 parts by weight of lithium cobaltate (LiCoO 2 ) powder as a positive electrode active material, 50 parts by weight of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (hereinafter also referred to as LAGP) powder as a solid electrolyte, conductive 20 parts by weight of acetylene black as an auxiliary agent and 16 parts by weight of polyvinyl butyral (PVB) resin as a binder were mixed with terpineol as a solvent to form a slurry, and the slurry was defoamed to prepare a positive electrode slurry.
  • LiCoO 2 lithium cobaltate
  • LAGP Li 1.5 Al 0.5 Ge 1.5
  • PV 4 polyvinyl butyral
  • the slurry was mixed with terpineol, and the slurry was defoamed to prepare a negative electrode slurry.
  • a stainless steel metal current collector foil with a thickness of 20 ⁇ m was used as the positive electrode current collector.
  • a positive electrode slurry as a first active material slurry was applied to one surface of the current collector foil and dried to prepare a positive electrode layer green sheet as a first active material layer.
  • the solid electrolyte slurry was applied on the surface of the positive electrode layer green sheet opposite to the surface facing the metal current collector foil and dried to prepare a solid electrolyte layer green sheet.
  • a negative electrode slurry as a second active material slurry is applied and dried on the surface of the solid electrolyte layer green sheet opposite to the positive electrode layer facing the green sheet, and the negative electrode layer as the second active material layer A green sheet was produced. Thereby, the laminated body green sheet as shown in FIG. 2 was produced.
  • a negative electrode current collector made of a metal current collector foil having a thickness of 20 ⁇ m similar to the positive electrode current collector was bonded. Then, the laminated body which consists of a laminated body green sheet which bonded the negative electrode collector was pressurized at 80 degreeC and 1000 kgf / cm ⁇ 2 > (98 MPa). Thereafter, the positive electrode current collector and the negative electrode current collector were cut into individual elements so as to be exposed on different surfaces of the laminate.
  • Tse peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Example 2 A laminated fired body was produced in the same manner as in Example 1 except that the negative electrode current collector was not bonded to the negative electrode layer green sheet of the produced laminated green sheet and was not cut.
  • a negative electrode current collector made of a stainless steel metal current collector foil having a thickness of 20 ⁇ m was bonded onto the negative electrode layer of the produced laminated fired body.
  • the laminated fired body on which the negative electrode current collector was bonded was pressed at 80 ° C. and 1000 kgf / cm 2 (98 MPa). Thereafter, the positive electrode current collector and the negative electrode current collector are cut into individual elements so as to be exposed on different surfaces of the laminated fired body, and the all-solid-state secondary battery of Example 2 as shown in FIG. Produced.
  • Tse peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Example 3 An all-solid secondary battery of Example 3 as shown in FIG. 1 was produced in the same manner as in Example 1 except that acrylic resin B was used as the binder to be mixed in the solid electrolyte slurry.
  • the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin B) contained in the solid electrolyte layer Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ⁇ Tse ⁇ Ta and Tb ⁇ Ta were satisfied.
  • Example 4 An all-solid secondary battery of Example 4 as shown in FIG. 1 was produced in the same manner as in Example 1 except that the binder mixed in the solid electrolyte slurry was PVB resin.
  • the binder mixed in the solid electrolyte slurry was PVB resin.
  • Ta thermogravimetric decrease peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Example 5 Continuous laminate green sheet production process> A laminate green sheet produced in the same manner as in Example 1 was cut into a predetermined size to produce a laminate. Five laminates were produced. Subsequently, five laminates were sequentially laminated to form a continuous laminate green sheet as shown in FIG. Finally, on the negative electrode layer green sheet not in contact with the metal current collector foil, a negative electrode current collector made of stainless steel metal current collector foil having a thickness of 20 ⁇ m similar to the positive electrode current collector is placed, as shown in FIG. A continuous laminate was obtained. Subsequently, the whole continuous laminate was pressurized at 80 ° C. and 1000 kgf / cm 2 (98 MPa).
  • Example 5 The continuous laminate was heated from room temperature to 700 ° C. in a nitrogen stream at a heating rate of 80 ° C./min, held at that temperature for 30 minutes, then cooled to room temperature by standing in the furnace, as shown in FIG. A serial all-solid secondary battery of Example 5 which is a continuous laminated fired body was produced.
  • Tse peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Comparative Example 1 The binder mixed with the positive electrode slurry, which is the first active material slurry, is acrylic resin B, the binder mixed with the solid electrolyte slurry is the PVB resin, and the binder mixed with the negative electrode slurry, which is the second active material slurry, An all-solid secondary battery of Comparative Example 1 was produced in the same manner as in Example 1 except that the acrylic resin A was used.
  • Tse peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Comparative Example 2 The binder mixed with the positive electrode slurry, which is the first active material slurry, is PVB resin, the binder mixed with the solid electrolyte slurry is acrylic resin B, and the binder mixed with the negative electrode slurry, which is the second active material slurry, An all-solid secondary battery of Comparative Example 2 was produced in the same manner as in Example 1 except that the acrylic resin A was used.
  • Tse peak temperature
  • Tb thermogravimetric decrease peak temperature
  • Comparative Example 3 Comparative Example as in Example 1 except that the binder mixed in the first active material slurry, the positive electrode slurry, the solid electrolyte slurry, and the second active material slurry, the negative electrode slurry was all PVB resin. 3 all-solid-state secondary batteries were produced.
  • the binder used in Comparative Example 3 the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease peak of the binder (PVB resin) contained in the solid electrolyte layer.
  • Tse temperature
  • Tb thermogravimetric decrease peak temperature
  • the electrochemical evaluation was performed about the produced all-solid-state secondary battery and series all-solid-state secondary battery as follows. (Evaluation method for all-solid-state secondary batteries of Examples 1 to 4 and Comparative Examples 1 to 3) Ten all solid state secondary batteries of each Example and Comparative Example were prepared and evaluated. The all solid state secondary batteries of Examples and Comparative Examples were charged with a constant current of 0.2 C until the voltage reached 2.7 V, and then discharged with a constant current of 0.2 C to a voltage of 1.5 V. The discharge capacity (0.2 C discharge capacity) at this time was defined as the reference capacity A. The reference capacity A was an average value of discharge capacities of ten all solid state secondary batteries.
  • the all solid state secondary batteries of the examples and comparative examples were charged to a voltage of 2.7 V at a constant current of 0.2 C, and then discharged to a voltage of 1.5 V at a constant current of 5 C.
  • the discharge capacity at this time was set to 5C discharge capacity B.
  • the 5C discharge capacity B was also an average value of the discharge capacity of 10 all solid state secondary batteries.
  • a discharge capacity maintenance ratio represented by a ratio (B / A (%)) of the discharge capacity of the 5C discharge capacity B to the reference capacity A is obtained. This was used as an evaluation standard for electrochemical evaluation.
  • the series all solid state secondary battery of Example 5 was charged to a voltage of 13.5 V at a constant current of 0.2 C, and then discharged to a voltage of 7.5 V at a constant current of 5 C.
  • the discharge capacity at this time was set to 5C discharge capacity B.
  • the 5C discharge capacity B was also set to the average value of the discharge capacity of 10 series all solid state secondary batteries.
  • a discharge capacity maintenance ratio represented by a ratio (B / A (%)) of 5C discharge capacity B to reference capacity A is obtained. Evaluation criteria for electrochemical evaluation were used.
  • Table 1 below shows the evaluation results of the electrochemical evaluation.
  • each of the all-solid-state secondary batteries of Examples 1 to 5 satisfying both the conditions of Tb ⁇ Tse ⁇ Ta and Tb ⁇ Ta shows an electrochemical evaluation indicating a sufficient discharge capacity maintenance rate. Results were obtained.
  • the all-solid-state secondary battery of Example 2 has a slightly lower discharge capacity retention rate than the all-solid-state secondary battery of Example 1, and the negative electrode current collector pasted after firing the negative electrode layer and the laminate green sheet It was estimated that the interfacial resistance between the body and the body was higher than that in Example 1. In the all-solid-state secondary battery of Example 5, the binder was less likely to be decomposed due to the continuous laminated structure. However, the rate of temperature increase was lower than in Examples 1 to 4, so that electrochemical evaluation was a problem.
  • Comparative Example 1 the all-solid-state secondary battery of Comparative Example 1 was subjected to electrochemical evaluation because delamination occurred between the positive electrode current collector and the positive electrode as the first active material layer in the firing process, and the electrode was destroyed. could not. Further, in Comparative Example 2 and Comparative Example 3, the reference capacity A and 5C discharge capacity B and the discharge capacity retention rate were significantly reduced. This was presumed to be because the binder in each layer remained up to the sintering temperature of the inorganic particles, so that the sintering was inhibited and the interface resistance was high.
  • the first binder included in the first electrode layer green sheet provided on the current collector and the solid electrolyte layer green sheet provided on the first electrode layer green sheet.
  • the thermogravimetric decrease peak temperature of the third binder contained in the second electrode layer green sheet provided on the solid electrolyte layer green sheet An all-solid secondary battery with good battery performance could be obtained without causing a significant decrease in the reference capacity A and 5C discharge capacity B and the discharge capacity retention rate.
  • the all-solid-state secondary battery manufactured by the manufacturing method of the present embodiment can be manufactured by firing the laminated green sheet at once, the manufacturing process of the all-solid-state secondary battery is simplified.
  • the most promising secondary battery that satisfies these requirements is an all-solid lithium ion secondary battery in which the entire structure of the negative electrode layer, the electrolyte layer, and the positive electrode layer is made of a solid material.
  • This all-solid-state lithium ion secondary battery is being developed as a battery having high energy density, high safety, and long life.
  • the all-solid-state lithium ion secondary battery currently in practical use is an all-solid-state secondary battery in which each of the negative electrode layer, the solid electrolyte layer, and the positive electrode layer is very thin, and its energy density is not high. Furthermore, since the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are produced by vapor deposition or sputtering, it is necessary to produce an all-solid lithium ion secondary battery in a reduced-pressure atmosphere. Is unsuitable.
  • Patent Document 1 to Patent Document 3 all the solid lithium ions that enable large area production and mass production by firing the green sheets of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer. Techniques for producing secondary batteries are being studied.
  • Patent Document 1 a positive electrode layer green sheet and a negative electrode layer green sheet are fired to produce a positive electrode layer fired body and a negative electrode layer fired body, and then a positive electrode layer fired body and a negative electrode through an ion conductive inorganic material layer green sheet. It describes that a layered fired body is sandwiched and refired to form a laminated fired body. Patent Document 1 discloses an all-solid secondary battery produced by sandwiching the laminated fired body between two current collector plates.
  • Patent Document 2 a positive electrode layer green sheet, an ion conductive inorganic material layer green sheet, and a negative electrode layer green sheet are laminated in order to form a laminated body and then collectively fired to form a laminated fired body.
  • Patent Document 3 discloses a laminate green in which a positive electrode layer green sheet and a negative electrode layer green sheet are printed on both surfaces of an ion conductive inorganic material layer green sheet, and each metal foil current collector paste is printed on the upper layer.
  • An all-solid secondary battery produced by batch firing sheets is disclosed.

Abstract

Provided are: a laminate green sheet and a continuous laminate green sheet, which are used to obtain an all-solid-state secondary battery having high battery performance through a simple manufacturing process; a method for manufacturing the same; and a method for manufacturing an all-solid-state secondary battery. A laminate green sheet (10) according to an aspect of the present invention is provided with: a positive electrode current collector (11); a positive electrode layer green sheet (12a) including a first binder; a solid electrolyte layer green sheet (13a) including a second binder; and a negative electrode layer green sheet (14a) including a third binder, wherein the ease of decomposition of the second binder is equal to or greater than that of the first binder, and the ease of decomposition of the third binder is greater than that of the first binder and equal to or greater than that of the second binder.

Description

積層体グリーンシート及び連続積層体グリーンシート、並びにそれらの製造方法及び全固体二次電池の製造方法LAMINATE GREEN SHEET, CONTINUOUS LAMINATE GREEN SHEET, METHOD FOR PRODUCING THEM,
　本発明は、積層体グリーンシート及び連続積層体グリーンシート、並びにそれらの製造方法及び全固体二次電池の製造方法に関する。 The present invention relates to a laminate green sheet, a continuous laminate green sheet, a production method thereof, and a production method of an all-solid-state secondary battery.
　電子機器に用いられる二次電池として最も有力であるのが、負極層、電解質層及び正極層の全構成が固体材料から成る全固体リチウムイオン二次電池（以下、全固体二次電池とも記載する）である。この全固体二次電池に関する技術としては、例えば、特許文献１～３に記載されたものがある。 The most prominent secondary battery used in electronic devices is an all-solid lithium ion secondary battery (hereinafter, also referred to as an all-solid secondary battery) in which the entire structure of the negative electrode layer, the electrolyte layer, and the positive electrode layer is made of a solid material. ). For example, Patent Documents 1 to 3 disclose techniques related to the all-solid-state secondary battery.
特開２０００－３４０２５５号JP 2000-340255 A 特許第４８４５２４４号Japanese Patent No. 4845244 特許第５４３０９３０号Patent No. 5430930
　しかしながら、特許文献１に開示された発明のように、正極層、固体電解質層、負極層から成る積層焼成体を正極集電体、負極集電体で挟み込んだ場合、正極集電体と正極層、負極集電体と負極層との界面抵抗が高くなり、電池性能が悪くなる可能性があるといった課題がある。また、全固体二次電池を作製するために焼成工程を２度経る必要があり、製造効率が悪くなる可能性があるという課題がある。 However, as in the invention disclosed in Patent Document 1, when a laminated fired body including a positive electrode layer, a solid electrolyte layer, and a negative electrode layer is sandwiched between a positive electrode current collector and a negative electrode current collector, the positive electrode current collector and the positive electrode layer There is a problem that the interface resistance between the negative electrode current collector and the negative electrode layer is increased, and the battery performance may be deteriorated. Moreover, in order to produce an all-solid-state secondary battery, it is necessary to pass through a baking process twice, and there exists a subject that manufacturing efficiency may worsen.
　また、特許文献２に開示された発明のように、正極層、固体電解質層、負極層の各グリーンシートを貼り合わせた積層体グリーンシートを一括焼成した場合、焼成工程は一工程であり、特許文献１と比較して製造効率は高い。しかしながら、特許文献２に開示された発明は、正極集電板と正極層との界面抵抗及び負極集電板と負極層との界面抵抗が高くなる可能性があるという課題がある。 In addition, as in the invention disclosed in Patent Document 2, when the laminated green sheet obtained by bonding the green sheets of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer is collectively fired, the firing process is a single process. Compared with Document 1, the production efficiency is high. However, the invention disclosed in Patent Document 2 has a problem that the interface resistance between the positive electrode current collector plate and the positive electrode layer and the interface resistance between the negative electrode current collector plate and the negative electrode layer may increase.
　さらに、特許文献３に開示された発明のように、正極集電体グリーンシート、正極層グリーンシート、固体電解質層グリーンシート、負極層グリーンシート及び負極集電体グリーンシートが積層されて成る積層体グリーンシートを一括焼成した場合、正極集電体と正極層、負極集電体と負極層との界面抵抗は低減すると考えられる。しかしながら、固体電解質層グリーンシートの両面に正極層グリーンシート、負極層グリーンシートを印刷形成し、その上層に金属箔集電体ペーストを印刷形成しており、製造方法が煩雑になる可能性があるという課題がある。 Further, as in the invention disclosed in Patent Document 3, a laminate in which a positive electrode current collector green sheet, a positive electrode layer green sheet, a solid electrolyte layer green sheet, a negative electrode layer green sheet, and a negative electrode current collector green sheet are laminated. When the green sheets are fired at once, the interface resistance between the positive electrode current collector and the positive electrode layer and between the negative electrode current collector and the negative electrode layer is considered to be reduced. However, the positive electrode layer green sheet and the negative electrode layer green sheet are printed on both sides of the solid electrolyte layer green sheet, and the metal foil current collector paste is printed on the upper layer, which may make the manufacturing method complicated. There is a problem.
　本発明は、このような点に鑑みてなされたものであり、簡易な作製工程で電池性能の高い全固体二次電池を提供することを目的とする。また、本発明は、簡易な作製工程で電池性能の高い全固体二次電池を得るために用いられる積層体グリーンシート及び連続積層体グリーンシート、並びにそれらの製造方法及び全固体二次電池の製造方法を提供することを目的とする。 The present invention has been made in view of these points, and an object thereof is to provide an all-solid-state secondary battery having high battery performance by a simple manufacturing process. The present invention also provides a laminate green sheet and a continuous laminate green sheet used for obtaining an all-solid secondary battery having high battery performance by a simple production process, a method for producing the same, and production of an all-solid secondary battery. It aims to provide a method.
　以上の課題を解決するため、本発明の一態様に係る積層体グリーンシートは、金属箔集電体と、前記金属箔集電体上に設けられ、第１バインダーを含む第１電極層グリーンシートと、前記第１電極層グリーンシート上に設けられ、第２バインダーを含む固体電解質層グリーンシートと、前記固体電解質層グリーンシート上に設けられ、第３バインダーを含む第２電極層グリーンシートと、を備え、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 In order to solve the above problems, a laminate green sheet according to an aspect of the present invention is provided with a metal foil current collector, and a first electrode layer green sheet provided on the metal foil current collector and including a first binder. A solid electrolyte layer green sheet provided on the first electrode layer green sheet and containing a second binder; a second electrode layer green sheet provided on the solid electrolyte layer green sheet and containing a third binder; The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, and the ease of decomposition of the third binder is It is larger than the easiness of decomposition of the first binder and equal to or easier than the easiness of decomposition of the second binder. To.
　また、本発明の一態様に係る連続積層体グリーンシートは、金属箔集電体と、前記金属箔集電体上に設けられ、第１バインダーを含む第１電極層グリーンシートと、前記第１電極層グリーンシート上に設けられ、第２バインダーを含む固体電解質層グリーンシートと、前記固体電解質層グリーンシート上に設けられ、第３バインダーを含む第２電極層グリーンシートと、を備える積層体グリーンシートが連続的に積層され、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 Moreover, the continuous laminated body green sheet which concerns on 1 aspect of this invention is provided on the said metal foil electrical power collector, the said metal foil electrical power collector, the 1st electrode layer green sheet containing a 1st binder, and the said 1st A laminate green comprising: a solid electrolyte layer green sheet including a second binder provided on an electrode layer green sheet; and a second electrode layer green sheet including a third binder provided on the solid electrolyte layer green sheet. Sheets are continuously laminated, and the ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, and the third binder is decomposed. The ease is greater than the ease of decomposing the first binder, and is equal to the ease of decomposing the second binder, or the easiness of decomposing the second binder. It is larger than is.
　また、本発明の一態様に係る積層体グリーンシートの製造方法は、金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程と、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程と、前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程と、を備え、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 The method for producing a laminate green sheet according to an aspect of the present invention includes applying a first electrode slurry containing a first binder on a metal foil current collector or printing and then drying the first electrode layer green. A first electrode layer green sheet forming step for forming a sheet, and a solid electrolyte slurry containing a second binder is applied or printed on the first electrode layer green sheet and then dried to form a solid electrolyte layer green sheet. Solid electrolyte layer green sheet forming step, and second electrode layer for forming second electrode layer green sheet by applying or printing slurry for second electrode containing third binder on said solid electrolyte layer green sheet and then drying A green sheet forming step, wherein the ease of decomposing the second binder is equal to the easiness of decomposing the first binder or the first The ease of decomposing the third binder is greater than the easiness of decomposing the first binder, and the easiness of decomposing the first binder is greater than the decomposability of the second binder, or It is characterized by greater than ease of disassembly.
　また、本発明の一態様に係る連続積層体グリーンシートの製造方法は、金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程と、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程と、前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程と、前記金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートが順に積層された積層体グリーンシートを、複数連続的に積層するグリーンシート積層工程と、を備え、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 The method for producing a continuous laminate green sheet according to an aspect of the present invention includes applying a first electrode slurry containing a first binder onto a metal foil current collector or printing and then drying the first electrode layer. A first electrode layer green sheet forming step for forming a green sheet, and a solid electrolyte slurry containing a second binder is applied or printed on the first electrode layer green sheet and then dried to form a solid electrolyte layer green sheet And forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying the slurry. Layer green sheet forming step, the metal foil current collector, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second electrode A green sheet laminating step of continuously laminating a plurality of laminated green sheets in which layer green sheets are sequentially laminated, and the ease of decomposing the second binder is equal to the ease of decomposing the first binder Or the easiness of decomposition of the first binder, the easiness of decomposition of the third binder is greater than the easiness of decomposition of the first binder and the same as the easiness of decomposition of the second binder, or It is larger than the ease of decomposition of the second binder.
　また、本発明の一態様に係る全固体二次電池の製造方法は、第１金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程、及び前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程を含み、前記第１金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートをこの順に備えた積層体グリーンシートを生成する積層体グリーンシート形成工程と、前記積層体グリーンシートの表面に露出する前記第２電極層グリーンシート上に、第２金属箔集電体を貼り合わせる第２金属箔集電体貼り合わせ工程と、前記積層体グリーンシート及び前記積層体グリーンシートに貼り合わされた前記第２金属箔集電体を含む積層体を一括して焼成する焼成工程と、を備え、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 In addition, in the method for manufacturing an all-solid-state secondary battery according to one aspect of the present invention, the first electrode slurry containing the first binder is applied or printed on the first metal foil current collector and then dried. A first electrode layer green sheet forming step of forming an electrode layer green sheet; a solid electrolyte slurry containing a second binder is applied or printed on the first electrode layer green sheet and then dried to form a solid electrolyte layer green sheet; A solid electrolyte layer green sheet forming step to be formed, and a second electrode layer green sheet formed by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying to form a second electrode layer green sheet Including an electrode layer green sheet forming step, the first metal foil current collector, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second A laminated green sheet forming step for producing a laminated green sheet having the extreme green sheets in this order, and a second metal foil current collector on the second electrode layer green sheet exposed on the surface of the laminated green sheet A second metal foil current collector pasting step for pasting the body, and firing to collectively fire the laminate including the laminate green sheet and the second metal foil current collector pasted to the laminate green sheet And the ease of decomposing the second binder is equal to or greater than the ease of decomposing the first binder, and the easiness of decomposing the third binder. Is greater than the ease of decomposition of the first binder, and is equal to the ease of decomposition of the second binder or the ease of decomposition of the second binder. And wherein the large.
　また、本発明の他の態様に係る全固体二次電池の製造方法は、第１金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程、及び前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程を含み、前記第１金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートをこの順に備えた積層体グリーンシートを生成する積層体グリーンシート形成工程と、前記積層体グリーンシートを複数積層して連続積層体グリーンシートを生成する連続積層体グリーンシート形成工程と、前記連続積層体グリーンシートの表面に露出する前記第２電極層グリーンシート上に、第２金属箔集電体を貼り合わせる第２金属箔集電体貼り合わせ工程と、前記連続積層体グリーンシート及び前記積層体グリーンシートに貼り合わされた前記第２金属箔集電体を含む積層体を一括して焼成する焼成工程と、を備え、前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きいことを特徴とする。 According to another aspect of the present invention, there is provided a method for producing an all-solid-state secondary battery, wherein a first electrode slurry containing a first binder is applied or printed on a first metal foil current collector and then dried. A first electrode layer green sheet forming step for forming a one electrode layer green sheet, a solid electrolyte slurry containing a second binder applied or printed on the first electrode layer green sheet, and then dried to form a solid electrolyte layer green sheet A solid electrolyte layer green sheet forming step of forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying the slurry. Including a two-electrode layer green sheet forming step, the first metal foil current collector, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the first A laminated green sheet forming step for producing a laminated green sheet having electrode layer green sheets in this order, and a continuous laminated green sheet forming step for producing a continuous laminated green sheet by laminating a plurality of the laminated green sheets, A second metal foil current collector bonding step of bonding a second metal foil current collector onto the second electrode layer green sheet exposed on the surface of the continuous multilayer green sheet, and the continuous multilayer green sheet And a firing step that collectively fires the laminate including the second metal foil current collector bonded to the laminate green sheet, and the ease of decomposing the second binder is the first binder. The ease of decomposing the third binder is equal to or greater than the ease of decomposing the first binder. Greater than the decomposition ease of loaders, and being greater than the decomposition ease of decomposition ease equal to or said second binder of said second binder.
　本発明によれば、簡易な作製工程で電池性能の高い全固体二次電池を提供することができる。また、本発明によれば、上述したような全固体二次電池を得るために用いられる積層体グリーンシート、連続積層体グリーンシートを得ることができる。さらに、本発明によれば、簡易に電池性能の高い全固体二次電池を得るための積層体グリーンシート、連続積層体グリーンシート及び全固体二次電池の製造方法を得ることができる。 According to the present invention, it is possible to provide an all solid state secondary battery having high battery performance with a simple manufacturing process. Moreover, according to this invention, the laminated body green sheet used in order to obtain the above all-solid-state secondary battery and a continuous laminated body green sheet can be obtained. Furthermore, according to this invention, the manufacturing method of the laminated body green sheet, the continuous laminated body green sheet, and an all-solid-state secondary battery for obtaining an all-solid-state secondary battery with high battery performance easily can be obtained.
本願の第１の実施形態に記載の全固体二次電池の構成を示す断面図である。It is sectional drawing which shows the structure of the all-solid-state secondary battery as described in 1st Embodiment of this application. 本願の第１の実施形態に記載の積層体グリーンシートの構成を示す断面図である。It is sectional drawing which shows the structure of the laminated body green sheet as described in 1st Embodiment of this application. 本願の第１の実施形態に記載の積層体グリーンシートの表面に負極集電体を貼り合わせた積層体の構成を示す断面図である。It is sectional drawing which shows the structure of the laminated body which bonded together the negative electrode collector on the surface of the laminated body green sheet as described in 1st Embodiment of this application. 本願の第２の実施形態に記載の直列全固体二次電池の構成を示す断面図である。It is sectional drawing which shows the structure of the series all-solid-state secondary battery as described in 2nd Embodiment of this application. 本願の第２の実施形態に記載の連続積層体グリーンシートの構成を示す断面図である。It is sectional drawing which shows the structure of the continuous laminated body green sheet as described in 2nd Embodiment of this application. 本願の第２の実施形態に記載の連続積層体グリーンシートの表面に負極集電体を貼り合わせた積層体の構成を示す断面図である。It is sectional drawing which shows the structure of the laminated body which bonded together the negative electrode collector on the surface of the continuous laminated body green sheet as described in 2nd Embodiment of this application.
　次に、本発明の各実施形態について図面を参照して説明する。
　ここで、図面は模式的なものであり、厚さと平面寸法との関係、各層の厚さの比率等は現実のものとは異なる。他にも、図面を簡潔にするために、周知の構造が略図で示されている。また、各図において、同一又は類似した機能を発揮する構成要素には同一の参照符号を付し、重複する説明は省略する。また、以下に示す実施形態は、本発明の技術的思想を具体化するための構成を例示するものであって、本発明の技術的思想は、構成部品の材質、形状、及び構造等が下記のものに特定するものでない。本発明の技術的思想は、特許請求の範囲に記載された請求項が規定する技術的範囲内において、種々の変更を加えることができる。 Next, each embodiment of the present invention will be described with reference to the drawings.
Here, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. In other instances, well-known structures are shown in schematic form in order to simplify the drawing. Moreover, in each figure, the same referential mark is attached | subjected to the component which exhibits the same or similar function, and the overlapping description is abbreviate | omitted. Further, the embodiment described below exemplifies a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is that the material, shape, structure, etc. of the component parts are as follows. It is not something specific. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
１．第１の実施形態
　以下の第１の実施形態において、本発明に係る単層の全固体二次電池及び全固体二次電池の製造方法について説明する。また、以下の第１の実施形態において、本発明に係る全固体二次電池の製造に用いられる積層体グリーンシート及び積層体グリーンシートの製造方法について説明する。 1. First Embodiment In the following first embodiment, a single-layer all-solid secondary battery and a method for manufacturing an all-solid secondary battery according to the present invention will be described. In the following first embodiment, a laminate green sheet used for producing an all solid state secondary battery according to the present invention and a method for producing the laminate green sheet will be described.
（１－１）全固体二次電池の構成
［全固体二次電池の構成］
　図１は、第１の実施形態で説明する全固体二次電池の断面図である。
　図１に示すように、第１の実施形態における全固体二次電池１は、金属箔集電体（第１金属箔集電体）からなる正極集電体１１と、正極集電体１１上に設けられた正極層１２と、正極層１２上に設けられた無機固体電解質層（以下、固体電解質層と記載する）１３と、固体電解質層１３上に設けられた負極層１４と、負極層１４上に設けられた金属箔集電体（第２金属箔集電体）からなる負極集電体１５と、を備えている。この構成は、後に詳細に説明するように、正極層グリーンシート１２ａ、固体電解質層グリーンシート１３ａ及び負極層グリーンシート１４ａを積層した積層体グリーンシートに少なくとも正極集電体１１及び負極集電体１５が貼り合わされた状態で一括焼成を行うという全固体二次電池１の製造方法により実現される。 (1-1) Configuration of all-solid secondary battery [Configuration of all-solid secondary battery]
FIG. 1 is a cross-sectional view of an all solid state secondary battery described in the first embodiment.
As shown in FIG. 1, the all-solid-state secondary battery 1 in the first embodiment includes a positive electrode current collector 11 made of a metal foil current collector (first metal foil current collector), and a positive electrode current collector 11. A positive electrode layer 12 provided on the positive electrode layer 12, an inorganic solid electrolyte layer (hereinafter referred to as a solid electrolyte layer) 13 provided on the positive electrode layer 12, a negative electrode layer 14 provided on the solid electrolyte layer 13, and a negative electrode layer 14, and a negative electrode current collector 15 made of a metal foil current collector (second metal foil current collector) provided on 14. As will be described in detail later, this configuration is such that at least the positive electrode current collector 11 and the negative electrode current collector 15 are formed on a laminate green sheet in which a positive electrode layer green sheet 12a, a solid electrolyte layer green sheet 13a, and a negative electrode layer green sheet 14a are stacked. This is realized by the manufacturing method of the all-solid-state secondary battery 1 in which batch firing is performed in a state where the is bonded.
（固体電解質層）
　固体電解質層１３は、固体電解質及び焼成後に固体電解質となるガラスの少なくとも一方を含んでいる。
　固体電解質層１３に含まれる固体電解質及び焼成後に固体電解質となるガラスは、電子の伝導性が小さく、リチウムイオンの伝導性が高い材料であれば特に限定されず、例えば、酸化物系固体電解質や硫化物系固体電解質の非晶質体（ガラス体）、結晶体、及びガラスセラミックス等が用いられる。特に、高温焼成が可能な酸化物系固体電解質が好ましく、ＮＡＳＩＣＯＮ（Ｎａ　ｓｕｐｅｒ　ｉｏｎｉｃ　ｃｏｎｄｕｃｔｏｒ）型酸化物、ペロブスカイト型酸化物、ＬＩＳＩＣＯＮ（Ｌｉｔｈｉｕｍ　ｓｕｐｅｒ　ｉｏｎｉｃ　ｃｏｎｄｕｃｔｏｒ）型酸化物、ガーネット型酸化物、酸化物ガラスなどを用いることが好ましい。このような高温焼成が可能な酸化物系固体電解質としては、例えば、Ｌｉ１．３Ａｌ０．３Ｔｉ１．７（ＰＯ４）３、Ｌｉ１．５Ａｌ０．５Ｇｅ１．５（ＰＯ４）３、Ｌｉ０．２９Ｌａ０．５７１ＴｉＯ３、Ｌｉ４ＳｉＯ４－Ｌｉ３ＰＯ４、Ｌｉ３ＢＯ３－Ｌｉ３ＰＯ４、Ｌｉ７Ｌａ３Ｚｒ２Ｏ１２、Ｌｉ３．４Ｖ０．６Ｓｉ０．４Ｏ４などを用いることができる。 (Solid electrolyte layer)
The solid electrolyte layer 13 includes at least one of a solid electrolyte and glass that becomes a solid electrolyte after firing.
The solid electrolyte contained in the solid electrolyte layer 13 and the glass that becomes the solid electrolyte after firing are not particularly limited as long as the material has low electron conductivity and high lithium ion conductivity. For example, an oxide solid electrolyte or An amorphous body (glass body), crystal body, glass ceramic, or the like of a sulfide-based solid electrolyte is used. In particular, an oxide-based solid electrolyte that can be fired at a high temperature is preferable. A NASICON (Na super ionic conductor) type oxide, a perovskite type oxide, a LISICON (Lithium super ionic conductor) type oxide, a garnet type oxide, an oxide glass Etc. are preferably used. Examples of the oxide-based solid electrolyte that can be fired at such a high temperature include Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 0.29 La 0.571 TiO 3 , Li 4 SiO 4 —Li 3 PO 4 , Li 3 BO 3 —Li 3 PO 4 , Li 7 La 3 Zr 2 O 12 , Li 3.4 V 0 .6 Si 0.4 O 4 or the like can be used.
　固体電解質層１３の厚さは、１μｍ以上５００μｍ以下の範囲内であることが好ましい。固体電解質層１３の厚さが１μｍよりも薄い場合、正極層１２と負極層１４とが短絡しやすくなり、全固体二次電池１の性能が低下するだけでなく、安全性も低下する可能性がある。また、固体電解質層１３の厚さが５００μｍよりも厚い場合、固体電解質層１３におけるリチウムイオン等の伝導イオンの移動が阻害されやすくなり、全固体二次電池１の出力が低くなる可能性がある。 The thickness of the solid electrolyte layer 13 is preferably in the range of 1 μm to 500 μm. When the thickness of the solid electrolyte layer 13 is thinner than 1 μm, the positive electrode layer 12 and the negative electrode layer 14 are easily short-circuited, and not only the performance of the all-solid-state secondary battery 1 may be reduced but also the safety may be reduced. There is. Moreover, when the thickness of the solid electrolyte layer 13 is thicker than 500 μm, the movement of conductive ions such as lithium ions in the solid electrolyte layer 13 is likely to be inhibited, and the output of the all-solid secondary battery 1 may be lowered. .
（正極層）
　正極層１２は、正極活物質と、固体電解質及び焼成後に固体電解質となるガラスの少なくとも一方とを含んでいる。
　正極層１２に含まれる正極活物質は、リチウムイオンを吸蔵放出することができる材料であればよく、特に限定されない。正極層１２は、負極層１４に含まれる活物質より貴な電位を示す活物質を正極活物質として含有する。 (Positive electrode layer)
The positive electrode layer 12 includes a positive electrode active material and at least one of a solid electrolyte and a glass that becomes a solid electrolyte after firing.
The positive electrode active material contained in the positive electrode layer 12 may be any material that can occlude and release lithium ions, and is not particularly limited. The positive electrode layer 12 contains, as a positive electrode active material, an active material that exhibits a higher potential than the active material contained in the negative electrode layer 14.
　正極活物質としては、例えば、ニッケルコバルトマンガン酸リチウム（ＬｉＮｉｘＣｏ１－ｙ－ｘＭｎｙＯ２）、コバルト酸リチウム（ＬｉＣｏＯ２）、ニッケル酸リチウム（ＬｉＮｉＯ２）、マンガン酸リチウム（ＬｉＭｎ２Ｏ４）、リン酸鉄リチウム（ＬｉＦｅＰＯ４）、リン酸コバルトリチウム（ＬｉＣｏＰＯ４）、リン酸マンガンリチウム（ＬｉＭｎＰＯ４）、リン酸バナジウムリチウム（Ｌｉ３Ｖ２（ＰＯ４）３）などのリチウム遷移金属化合物を用いることができる。
　また、正極層１２に含まれる固体電解質としては、固体電解質層１３に含まれる固体電解質と同様の材料を用いることができる。正極層１２に含まれる固体電解質は、２種以上を混合して用いてもよい。また、正極層１２に含まれる固体電解質は、固体電解質層１３及び後述する負極層１４に含まれる固体電解質と同じであってもよく、異なっていてもよい。 As the positive electrode active material, for example, lithium nickel cobalt manganese oxide (LiNi x Co 1-y- x Mn y O 2), lithium cobalt oxide (LiCoO 2), lithium nickelate (LiNiO 2), lithium manganate (LiMn 2 Li transition such as O 4 ), lithium iron phosphate (LiFePO 4 ), lithium cobalt phosphate (LiCoPO 4 ), lithium manganese phosphate (LiMnPO 4 ), lithium vanadium phosphate (Li 3 V 2 (PO 4 ) 3 ) Metal compounds can be used.
Further, as the solid electrolyte contained in the positive electrode layer 12, the same material as the solid electrolyte contained in the solid electrolyte layer 13 can be used. Two or more solid electrolytes contained in the positive electrode layer 12 may be mixed and used. Further, the solid electrolyte contained in the positive electrode layer 12 may be the same as or different from the solid electrolyte contained in the solid electrolyte layer 13 and the negative electrode layer 14 described later.
　正極層１２は、導電助剤を含有していてもよい。導電助剤としては、導電性を有するものであれば特に限定されず、例えば、導電性炭素材料、特にカーボンブラックや活性炭、カーボン炭素繊維等を用いることができる。
　正極層１２における導電助剤の含有量は、正極活物質の重量に対して０重量％超９０重量％未満の範囲内であることが好ましい。導電助剤の含有量が９０重量％以上であると、正極層１２中の正極活物質量が不足してリチウム吸蔵容量が低下してしまうことがあるためである。
　正極層１２は、所望の電池容量に応じて任意の厚さを選択することができる。 The positive electrode layer 12 may contain a conductive additive. The conductive auxiliary agent is not particularly limited as long as it has conductivity. For example, a conductive carbon material, particularly carbon black, activated carbon, carbon carbon fiber, or the like can be used.
The content of the conductive additive in the positive electrode layer 12 is preferably in the range of more than 0% and less than 90% by weight with respect to the weight of the positive electrode active material. This is because if the content of the conductive auxiliary is 90% by weight or more, the amount of the positive electrode active material in the positive electrode layer 12 may be insufficient and the lithium storage capacity may be reduced.
The positive electrode layer 12 can be selected to have an arbitrary thickness according to a desired battery capacity.
（負極層）
　負極層１４は、負極活物質と、固体電解質及び焼成後に固体電解質となるガラスの少なくとも一方とを含んでいる。
　負極層１４に含まれる負極活物質は、リチウムイオンを吸蔵放出することができる材料であればよく、特に限定されない。負極層１４は、正極層１２に含まれる活物質より卑な電位を示す活物質を負極活物質として含有する。 (Negative electrode layer)
The negative electrode layer 14 includes a negative electrode active material and at least one of a solid electrolyte and glass that becomes a solid electrolyte after firing.
The negative electrode active material included in the negative electrode layer 14 may be any material that can occlude and release lithium ions, and is not particularly limited. The negative electrode layer 14 contains, as a negative electrode active material, an active material that shows a lower potential than the active material contained in the positive electrode layer 12.
　負極活物質としては、例えば、ハードカーボン、ソフトカーボン、グラファイト等の炭素材料や、Ｓｎ系合金、Ｓｉ系合金などの合金材料、ＬｉＣｏＮなどの窒化物、チタン酸リチウム（Ｌｉ４Ｔｉ５Ｏ１２）、リン酸バナジウムリチウム（Ｌｉ３Ｖ２（ＰＯ４）３）などのリチウム遷移金属酸化物を用いることができる。また、負極活物質として金属リチウム箔を用いてもよい。
　また、負極層１４に含まれる固体電解質としては、固体電解質層１３及び正極層１２に含まれる固体電解質と同様の材料を用いることができる。負極層１４に含まれる固体電解質は、２種以上を混合して用いてもよい。また、負極層１４に含まれる固体電解質は、固体電解質層１３及び正極層１２に含まれる固体電解質と同じであってもよく、異なっていてもよい。 Examples of the negative electrode active material include carbon materials such as hard carbon, soft carbon, and graphite, alloy materials such as Sn-based alloys and Si-based alloys, nitrides such as LiCoN, and lithium titanate (Li 4 Ti 5 O 12 ). Lithium transition metal oxides such as lithium vanadium phosphate (Li 3 V 2 (PO 4 ) 3 ) can be used. Moreover, you may use metal lithium foil as a negative electrode active material.
In addition, as the solid electrolyte contained in the negative electrode layer 14, the same material as the solid electrolyte contained in the solid electrolyte layer 13 and the positive electrode layer 12 can be used. Two or more kinds of solid electrolytes contained in the negative electrode layer 14 may be mixed and used. Further, the solid electrolyte contained in the negative electrode layer 14 may be the same as or different from the solid electrolyte contained in the solid electrolyte layer 13 and the positive electrode layer 12.
　負極層１４は、導電助剤を含有していてもよい。導電助剤としては、正極層１２に含まれる導電助剤と同様に導電性を有するものであれば特に限定されず、例えば、導電性炭素材料、特にカーボンブラックや活性炭、カーボン炭素繊維等を用いることができる。
　負極層１４における導電助剤の含有量は、負極活物質の重量に対して０重量％超９０重量％未満の範囲内であることが好ましい。導電助剤の含有量が９０重量％以上であると、負極層１４中の負極活物質量が不足してリチウム吸蔵容量が低下してしまうことがあるためである。
　負極層１４は、所望の電池容量に応じて任意の厚さを選択することができる。 The negative electrode layer 14 may contain a conductive additive. The conductive auxiliary agent is not particularly limited as long as it has conductivity similar to the conductive auxiliary agent contained in the positive electrode layer 12. For example, a conductive carbon material, particularly carbon black, activated carbon, carbon carbon fiber, or the like is used. be able to.
The content of the conductive additive in the negative electrode layer 14 is preferably in the range of more than 0% and less than 90% by weight with respect to the weight of the negative electrode active material. This is because when the content of the conductive auxiliary is 90% by weight or more, the amount of the negative electrode active material in the negative electrode layer 14 is insufficient, and the lithium storage capacity may be reduced.
The negative electrode layer 14 can be selected to have an arbitrary thickness according to a desired battery capacity.
（金属箔集電体）
　正極層１２と密着して設けられる正極集電体１１と、負極層１４と密着して設けられる負極集電体１５とは、それぞれ金属箔集電体からなる。なお、以下、正極集電体１１と負極集電体１５との双方を指す場合、又は正極集電体１１と負極集電体１５とを区別しない場合には、正極集電体１１及び負極集電体１５を「金属箔集電体」と記載する場合がある。
　金属箔集電体の材料としては、導電性を有する材料であれば特に限定はされず、例えば、ステンレス、ニッケル、アルミニウム、鉄、チタン、銅、パラジウム、金及び白金などの金属材料を用いることができる。また、金属箔集電体の材料として、後述する焼成条件で溶融及び分解しないことや、金属箔集電体にかかる電池作動電位や導電性を考慮して選択することが好ましい。 (Metal foil current collector)
The positive electrode current collector 11 provided in close contact with the positive electrode layer 12 and the negative electrode current collector 15 provided in close contact with the negative electrode layer 14 are each made of a metal foil current collector. Hereinafter, when referring to both the positive electrode current collector 11 and the negative electrode current collector 15, or when the positive electrode current collector 11 and the negative electrode current collector 15 are not distinguished from each other, the positive electrode current collector 11 and the negative electrode current collector 15 are referred to. The electric conductor 15 may be described as “metal foil current collector”.
The material of the metal foil current collector is not particularly limited as long as it is a conductive material. For example, metal materials such as stainless steel, nickel, aluminum, iron, titanium, copper, palladium, gold, and platinum are used. Can do. The material of the metal foil current collector is preferably selected in consideration of not being melted and decomposed under the firing conditions described later, and the battery operating potential and conductivity of the metal foil current collector.
　金属箔集電体の厚さは、３μｍ以上５０μｍ以下の範囲内であることが好ましい。金属箔集電体の厚さが３μｍ以上５０μｍ以下の範囲内である場合、積層焼成体の製造時において金属箔集電体にクラック等が入りにくく、また、積層体グリーンシート１０を十分に支持する厚みが得られる。 The thickness of the metal foil current collector is preferably in the range of 3 μm to 50 μm. When the thickness of the metal foil current collector is in the range of 3 μm or more and 50 μm or less, the metal foil current collector is not easily cracked during the production of the laminated fired body, and sufficiently supports the laminated green sheet 10 Thickness to be obtained.
（１－２）積層体グリーンシートの構成
　以下、積層体グリーンシート１０について説明する。
［積層体グリーンシートの構成］
　図２は、第１の実施形態で用いられる積層体グリーンシート１０の断面図である。
　図２に示すように、第１の実施形態における積層体グリーンシート１０は、金属箔集電体からなる正極集電体１１と、正極集電体１１上に設けられた正極層グリーンシート１２ａと、正極層グリーンシート１２ａ上に設けられた固体電解質層グリーンシート１３ａと、固体電解質層グリーンシート１３ａ上に設けられた負極層グリーンシート１４ａと、を備えている。後述するように、正極層グリーンシート１２ａ、固体電解質層グリーンシート１３ａ及び負極層グリーンシート１４ａのそれぞれに含まれるバインダーは、積層体グリーンシート１０の正極集電体１１より遠い層程分解しやすいバインダーを含むように形成する。すなわち、積層体グリーンシート１０では、正極集電体１１より遠い層程分解しやすいバインダーを含むように形成する。
　以下、各グリーンシートについて説明する。 (1-2) Configuration of Laminated Green Sheet Hereinafter, the laminated green sheet 10 will be described.
[Configuration of laminated green sheet]
FIG. 2 is a cross-sectional view of the laminate green sheet 10 used in the first embodiment.
As shown in FIG. 2, the laminate green sheet 10 in the first embodiment includes a positive electrode current collector 11 made of a metal foil current collector, and a positive electrode layer green sheet 12a provided on the positive electrode current collector 11. The solid electrolyte layer green sheet 13a provided on the positive electrode layer green sheet 12a and the negative electrode layer green sheet 14a provided on the solid electrolyte layer green sheet 13a are provided. As will be described later, the binder contained in each of the positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a is a binder that is more easily decomposed in a layer farther than the positive electrode current collector 11 of the laminate green sheet 10. To include. That is, the laminate green sheet 10 is formed so as to include a binder that is more easily decomposed in layers farther from the positive electrode current collector 11.
Hereinafter, each green sheet will be described.
（固体電解質層グリーンシート）
　固体電解質層グリーンシート１３ａは、固体電解質及び有機樹脂からなるバインダーが溶媒に分散された固体電解質用スラリーが後述する正極層グリーンシート１２ａ又は負極層グリーンシート１４ａ上に塗布もしくは印刷され、乾燥されることにより形成される。固体電解質用スラリーの調製方法は特に限定されない。
　固体電解質層グリーンシート１３ａが焼成されることにより、固体電解質層１３が得られる。 (Solid electrolyte layer green sheet)
The solid electrolyte layer green sheet 13a is coated or printed on a positive electrode layer green sheet 12a or a negative electrode layer green sheet 14a, which will be described later, and a solid electrolyte slurry in which a binder made of a solid electrolyte and an organic resin is dispersed in a solvent, and then dried. Is formed. The method for preparing the solid electrolyte slurry is not particularly limited.
The solid electrolyte layer 13 is obtained by firing the solid electrolyte layer green sheet 13a.
（正極層グリーンシート）
　正極層グリーンシート１２ａは、正極活物質、固体電解質及び有機物からなるバインダーが溶媒に分散された正極用スラリーが、金属箔集電体からなる正極集電体１１又は固体電解質層グリーンシート１３ａ上に塗布もしくは印刷され、乾燥されることにより形成される。正極用スラリーの調製方法は特に限定されない。
　正極層グリーンシート１２ａが焼成されることにより、正極層１２が得られる。 (Positive layer green sheet)
In the positive electrode layer green sheet 12a, a positive electrode slurry in which a binder made of a positive electrode active material, a solid electrolyte, and an organic substance is dispersed in a solvent is placed on the positive electrode current collector 11 made of a metal foil current collector or the solid electrolyte layer green sheet 13a. It is formed by coating or printing and drying. The method for preparing the positive electrode slurry is not particularly limited.
The positive electrode layer 12 is obtained by firing the positive electrode layer green sheet 12a.
（負極層グリーンシート）
　負極層グリーンシート１４ａは、負極活物質、固体電解質及び有機物からなるバインダーが溶媒に分散された負極用スラリーが、金属箔集電体からなる負極集電体１５又は固体電解質層グリーンシート１３ａ上に塗布もしくは印刷され、乾燥されることにより形成される。負極用スラリーの調製方法は特に限定されない。
　負極層グリーンシート１４ａが焼成されることにより、負極層１４が得られる。 (Negative electrode layer green sheet)
In the negative electrode layer green sheet 14a, a negative electrode slurry in which a binder made of a negative electrode active material, a solid electrolyte and an organic substance is dispersed in a solvent is formed on the negative electrode current collector 15 made of a metal foil current collector or the solid electrolyte layer green sheet 13a. It is formed by coating or printing and drying. The method for preparing the negative electrode slurry is not particularly limited.
The negative electrode layer green sheet 14a is fired, whereby the negative electrode layer 14 is obtained.
（金属箔集電体）
　金属箔集電体は、積層体グリーンシート１０製造時に正極層グリーンシート１２ａと密着して設けられる正極集電体１１又は負極層グリーンシート１４ａと密着して設けられる負極集電体１５である。正極集電体１１及び負極集電体１５は、全固体二次電池１に用いられる正極集電体１１及び負極集電体１５である。 (Metal foil current collector)
The metal foil current collector is the positive electrode current collector 11 provided in close contact with the positive electrode layer green sheet 12a or the negative electrode current collector 15 provided in close contact with the negative electrode layer green sheet 14a when the laminate green sheet 10 is manufactured. The positive electrode current collector 11 and the negative electrode current collector 15 are the positive electrode current collector 11 and the negative electrode current collector 15 used in the all solid state secondary battery 1.
　なお、積層体グリーンシート１０は、金属箔集電体と、金属箔集電体上に設けられた第１電極層グリーンシートと、第１電極層グリーンシート上に設けられた固体電解質層グリーンシートと、固体電解質層グリーンシート上に設けられた第２電極層グリーンシートと、を少なくとも備えていればよい。
　このため、積層体グリーンシート１０は、図２に示す構成以外にも、金属箔集電体からなる負極集電体１５と、負極集電体１５上に設けられた負極層グリーンシート１４ａと、負極層グリーンシート１４ａ上に設けられた固体電解質層グリーンシート１３ａと、固体電解質層グリーンシート１３ａ上に設けられた正極層グリーンシート１２ａと、を備えた構成であってもよい。この場合、積層体グリーンシート１０の負極集電体１５から遠い層程分解しやすいバインダーを含むように各層を形成する。 The laminate green sheet 10 includes a metal foil current collector, a first electrode layer green sheet provided on the metal foil current collector, and a solid electrolyte layer green sheet provided on the first electrode layer green sheet. And a second electrode layer green sheet provided on the solid electrolyte layer green sheet.
Therefore, in addition to the configuration shown in FIG. 2, the laminate green sheet 10 includes a negative electrode current collector 15 made of a metal foil current collector, a negative electrode layer green sheet 14a provided on the negative electrode current collector 15, The structure provided with the solid electrolyte layer green sheet 13a provided on the negative electrode layer green sheet 14a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be sufficient. In this case, each layer is formed so as to include a binder that is more easily decomposed as the layer farther from the negative electrode current collector 15 of the multilayer green sheet 10.
（１－３）積層体グリーンシートの製造方法
　以下、積層体グリーンシート１０及び全固体二次電池１の製造方法について説明する。
　積層体グリーンシート１０の製造方法は、金属箔集電体からなる正極集電体１１上に、正極活物質を含む正極用スラリーを塗布又は印刷したのち乾燥して正極層グリーンシート１２ａを形成する正極層グリーンシート形成工程と、正極層グリーンシート１２ａ上に固体電解質を含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシート１３ａを形成する固体電解質層グリーンシート形成工程と、固体電解質層グリーンシート１３ａ上に、負極活物質を含む負極用スラリーを塗布又は印刷したのち乾燥して負極層グリーンシート１４ａを形成する負極層グリーンシート形成工程と、を備えている。 (1-3) Method for Producing Laminate Green Sheet Hereinafter, a method for producing the laminate green sheet 10 and the all-solid-state secondary battery 1 will be described.
In the method of manufacturing the laminate green sheet 10, a positive electrode slurry containing a positive electrode active material is applied or printed on a positive electrode current collector 11 made of a metal foil current collector and then dried to form a positive electrode layer green sheet 12a. A positive electrode layer green sheet forming step, a solid electrolyte layer green sheet forming step of forming a solid electrolyte layer green sheet 13a by applying or printing a slurry for solid electrolyte containing a solid electrolyte on the positive electrode layer green sheet 12a and then drying; A negative electrode layer green sheet forming step in which a negative electrode slurry containing a negative electrode active material is applied or printed on the solid electrolyte layer green sheet 13a and then dried to form a negative electrode layer green sheet 14a.
（固体電解質層グリーンシートの製造方法）
　固体電解質層グリーンシート１３ａは、固体電解質及び有機物からなるバインダーを溶媒と共に混合して形成された固体電解質用スラリーを塗布もしくは印刷したのち、乾燥して形成される。固体電解質用スラリーは、例えば後述する正極層グリーンシート１２ａ又は負極層グリーンシート１４ａ上に塗布される。固体電解質用スラリーの調製方法は特に限定されない。 (Method for producing solid electrolyte layer green sheet)
The solid electrolyte layer green sheet 13a is formed by applying or printing a solid electrolyte slurry formed by mixing a solid electrolyte and an organic substance binder together with a solvent, and then drying. The solid electrolyte slurry is applied on, for example, a positive electrode layer green sheet 12a or a negative electrode layer green sheet 14a described later. The method for preparing the solid electrolyte slurry is not particularly limited.
（正極層グリーンシートの製造方法）
　正極層グリーンシート１２ａは、正極活物質、固体電解質及び有機物からなるバインダーを溶媒と共に混合して正極用スラリーを塗布もしくは印刷したのち、乾燥して形成される。正極用スラリーは、正極集電体１１又は後述する固体電解質層グリーンシート１３ａ上に塗布される。正極用スラリーの調製方法は特に限定されない。 (Method for producing positive electrode layer green sheet)
The positive electrode layer green sheet 12 a is formed by mixing a positive electrode active material, a solid electrolyte, and an organic substance binder together with a solvent and applying or printing a positive electrode slurry, followed by drying. The positive electrode slurry is applied on the positive electrode current collector 11 or a solid electrolyte layer green sheet 13a described later. The method for preparing the positive electrode slurry is not particularly limited.
（負極層グリーンシートの製造方法）
　負極層グリーンシート１４ａは、負極活物質、固体電解質及び有機物からなるバインダーを溶媒と共に混合して負極用スラリーを塗布もしくは印刷したのち、乾燥して形成される。負極用スラリーは、負極集電体１５又は後述する固体電解質層グリーンシート１３ａ上に塗布される。負極用スラリーの調製方法は特に限定されない。 (Method for producing negative electrode layer green sheet)
The negative electrode layer green sheet 14a is formed by mixing a negative electrode active material, a solid electrolyte, and an organic substance binder together with a solvent and applying or printing a negative electrode slurry, followed by drying. The negative electrode slurry is applied on the negative electrode current collector 15 or a solid electrolyte layer green sheet 13a described later. The method for preparing the negative electrode slurry is not particularly limited.
　正極用スラリー、負極用スラリー及び固体電解質用スラリーに含まれるバインダーは、積層体グリーンシートの焼成条件においてバインダーが熱により分解する際の重量減少量の最も大きい温度を熱重量減少ピーク温度としたときに、以下の条件を満たす。
　すなわち、積層体グリーンシートにおいて集電体上に設けられた第１電極層グリーンシートに含まれるバインダーを第１バインダー、第１電極層グリーンシート上に設けられた固体電解質層グリーンシートに含まれるバインダーを第２バインダー、固体電解質層グリーンシート上に設けられた第２電極層グリーンシートに含まれるバインダーを第３バインダーとした際に、（ｉ）第２バインダーの分解しやすさは、第１バインダーの分解しやすさと同等か又は第１バインダーの分解しやすさよりも大きく、（ii）第３バインダーの分解しやすさは、第１バインダーの分解しやすさよりも大きく、かつ第２バインダーの分解しやすさと同等か又は第２バインダーの分解しやすさよりも大きい。 When the binder contained in the positive electrode slurry, the negative electrode slurry, and the solid electrolyte slurry has a maximum weight loss amount when the binder decomposes by heat under the firing conditions of the laminate green sheet, the thermal weight reduction peak temperature is used. In addition, the following conditions are satisfied.
That is, in the laminate green sheet, the binder contained in the first electrode layer green sheet provided on the current collector is the first binder, and the binder contained in the solid electrolyte layer green sheet provided on the first electrode layer green sheet. Is the second binder, and the binder contained in the second electrode layer green sheet provided on the solid electrolyte layer green sheet is the third binder. (I) The ease of decomposition of the second binder is as follows: (Ii) The ease of decomposing the third binder is greater than the easiness of decomposing the first binder and the decomposing of the second binder. It is equal to the ease or greater than the ease of decomposing the second binder.
　また、上述した各バインダーについて、第１バインダーの熱重量減少ピーク温度（Ｔａ）と、第２バインダーの熱重量減少ピーク温度（Ｔｓｅ）と、第３バインダーの熱重量減少ピーク温度（Ｔｂ）とが、下記の式（１）及び式（２）の双方を満たすことがより好ましい。
　　　　Ｔｂ≦Ｔｓｅ≦Ｔａ　　　　　　　　　・・・（１）
　　　　Ｔｂ＜Ｔａ　　　　　　　　　　　　　・・・（２）
　なお、第１電極層グリーンシート及び第２電極層グリーンシートは、第１電極層グリーンシートが正極層グリーンシート１２ａである場合、第２電極層グリーンシートは負極層グリーンシート１４ａである。また、第１電極層グリーンシートが負極層グリーンシート１４ａである場合、第２電極層グリーンシートは正極層グリーンシート１２ａである。 For each of the binders described above, the thermogravimetric decrease peak temperature (Tse) of the first binder, the thermogravimetric decrease peak temperature (Tse) of the second binder, and the thermogravimetric decrease peak temperature (Tb) of the third binder are: It is more preferable to satisfy both the following formulas (1) and (2).
Tb ≦ Tse ≦ Ta (1)
Tb <Ta (2)
In the first electrode layer green sheet and the second electrode layer green sheet, when the first electrode layer green sheet is the positive electrode layer green sheet 12a, the second electrode layer green sheet is the negative electrode layer green sheet 14a. When the first electrode layer green sheet is the negative electrode layer green sheet 14a, the second electrode layer green sheet is the positive electrode layer green sheet 12a.
　一段階で粒子の焼結温度まで昇温するような焼成工程は製造時間が短縮でき、製造コストの低減が可能だが、このような焼成工程においては、バインダーの分解ガスが一度に多量に発生する。このため、例えば集電体に近い第１電極層グリーンシート内の第１バインダーが分解する際には、第１バインダーが分解されることにより生じたガスが固体電解質層グリーンシートや第２電極層グリーンシートに影響を及ぼす可能性がある。
　しかしながら、本実施形態では、積層体グリーンシートの焼成時において、集電体に遠い層から先にバインダーが分解することにより、集電体に遠い層から電解質層又は固体電解質層が形成される。このため、集電体に近い側の層のバインダーが分解する際にも、集電体に遠い側の層にガスの影響が及びにくく、全固体二次電池製造時における電極破壊が生じたり、電池性能が低下したりすることを防止することができる。 A firing process in which the temperature is raised to the sintering temperature of the particles in one step can shorten the production time and reduce the production cost, but in such a firing process, a large amount of binder decomposition gas is generated at one time. . For this reason, for example, when the first binder in the first electrode layer green sheet close to the current collector is decomposed, the gas generated by the decomposition of the first binder is converted into the solid electrolyte layer green sheet or the second electrode layer. May affect green sheets.
However, in this embodiment, when the laminated green sheet is fired, the binder is decomposed first from the layer far from the current collector, so that the electrolyte layer or the solid electrolyte layer is formed from the layer far from the current collector. For this reason, even when the binder on the layer near the current collector is decomposed, the gas on the layer far from the current collector is less likely to be affected by the gas, causing electrode destruction during the production of an all-solid-state secondary battery, It can prevent that battery performance falls.
　バインダーとしては、例えば、ポリビニルアルコール、ポリビニルブチラール、ポリビニルアセタール、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、エチルセルロース、アクリル樹脂などを用いることができる。 As the binder, for example, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinylidene fluoride, polytetrafluoroethylene, ethyl cellulose, acrylic resin, and the like can be used.
　正極層グリーンシート１２ａ、負極層グリーンシート１４ａ及び固体電解質層グリーンシート１３ａにおいて、各バインダーは、３重量％以上４０重量％以下の範囲内で含まれることが好ましく、３重量％以上２５重量％以下の範囲内であることがより好ましい。すなわち、各スラリーから溶媒を除いた固形分全体に対するバインダーの含有量が３重量％以上４０重量％以下の範囲内であることが好ましく、３重量％以上２５重量％以下の範囲内であることがより好ましい。
　バインダーの含有量が３重量％より少ない場合、例えば活物質同士又は固体電解質同士が十分に結着することできない場合がある。また、バインダーの含有量が４０重量％より大きい場合には、体積あたりの電池容量が低下する。 In the positive electrode layer green sheet 12a, the negative electrode layer green sheet 14a, and the solid electrolyte layer green sheet 13a, each binder is preferably included in the range of 3 wt% to 40 wt%, and is preferably 3 wt% to 25 wt%. It is more preferable to be within the range. That is, the binder content relative to the entire solid content excluding the solvent from each slurry is preferably in the range of 3 wt% to 40 wt%, and preferably in the range of 3 wt% to 25 wt%. More preferred.
When the binder content is less than 3% by weight, for example, active materials or solid electrolytes may not be sufficiently bound. On the other hand, when the content of the binder is larger than 40% by weight, the battery capacity per volume decreases.
　正極層グリーンシート１２ａ、負極層グリーンシート１４ａ及び固体電解質層グリーンシート１３ａは、焼成時に各グリーンシート内においてマトリックス構造の形成を促進し、焼成温度を低下させる焼成助剤を含有していてもよい。焼成助剤は正極活物質、負極活物質及び固体電解質と反応せず、正極活物質、負極活物質及び固体電解質の融着温度よりも軟化点温度が低ければ特に限定はされず、例えばホウ素化合物を用いることができる。正極層グリーンシート１２ａ、負極層グリーンシート１４ａ及び固体電解質層グリーンシート１３ａの焼成助剤の含有量と焼成温度を調整することで、積層焼成体を焼成により形成する際に、各層の内部歪や内部応力によるクラックを防止するとともに、マトリックス構造の形成を促進することができる。 The positive electrode layer green sheet 12a, the negative electrode layer green sheet 14a, and the solid electrolyte layer green sheet 13a may contain a firing aid that promotes formation of a matrix structure in each green sheet during firing and lowers the firing temperature. . The firing aid is not particularly limited as long as it does not react with the positive electrode active material, the negative electrode active material, and the solid electrolyte, and the softening point temperature is lower than the fusion temperature of the positive electrode active material, the negative electrode active material, and the solid electrolyte. Can be used. By adjusting the content and firing temperature of the firing aid of the positive electrode layer green sheet 12a, the negative electrode layer green sheet 14a, and the solid electrolyte layer green sheet 13a, While preventing cracks due to internal stress, formation of a matrix structure can be promoted.
　焼成助剤は、リチウムイオン伝導性を有する材料でもリチウムイオン伝導性を有しない材料でも構わないが、リチウムイオン伝導性を有する材料が好ましい。リチウムイオン伝導性を有しない焼成助剤の含有量は各グリーンシート内に含有される固体電解質重量に対して５重量％以下が好ましく、より好ましくは３重量％以下である。リチウムイオン伝導性を有する焼成助剤の含有量は各グリーンシート内に含有される固体電解質重量に対して５０重量％以下の範囲内で含まれることが好ましい。焼成助剤が、過剰に含まれると各グリーンシートを焼成して得た積層焼成体におけるリチウムイオン伝導性が低下し、電池性能が低下する場合がある。 The firing aid may be a material having lithium ion conductivity or a material having no lithium ion conductivity, but a material having lithium ion conductivity is preferable. The content of the firing aid having no lithium ion conductivity is preferably 5% by weight or less, more preferably 3% by weight or less, based on the weight of the solid electrolyte contained in each green sheet. The content of the sintering aid having lithium ion conductivity is preferably included within a range of 50% by weight or less with respect to the weight of the solid electrolyte contained in each green sheet. If the firing aid is excessively contained, the lithium ion conductivity in the laminated fired body obtained by firing each green sheet is lowered, and the battery performance may be lowered.
　正極用スラリー、負極用スラリー及び固体電解質用スラリーに用いられる溶媒は、上述したバインダーを溶解可能であれば特に限定されないが、例えばエタノール、イソプロパノール、ｎ－ブタノール等のアルコール類、トルエン、ターピネオール、酢酸エチル、酢酸ブチル、アセトン、メチルエチルケトン、メチルイソブチルケトン、エチレングリコールエチルエーテル、イソホロン、乳酸ブチル、ジオクチルフタレート、ジオクチルアジペート、ベンジルアルコール、Ｎ，Ｎ－ジメチルホルムアミド（ＤＭＦ）、Ｎ－メチル－２－ピロリドン（ＮＭＰ）などの有機溶剤、及び水を用いることができる。なお、これらの溶媒は単独で用いてもよく、２種以上を併用してもよい。スラリーの乾燥が容易であることから、溶媒の沸点は２００℃以下であることが好ましい。 The solvent used in the positive electrode slurry, the negative electrode slurry, and the solid electrolyte slurry is not particularly limited as long as the above-described binder can be dissolved. For example, alcohols such as ethanol, isopropanol, and n-butanol, toluene, terpineol, and acetic acid. Ethyl, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol ethyl ether, isophorone, butyl lactate, dioctyl phthalate, dioctyl adipate, benzyl alcohol, N, N-dimethylformamide (DMF), N-methyl-2-pyrrolidone ( Organic solvents such as NMP) and water can be used. In addition, these solvents may be used independently and may use 2 or more types together. Since the slurry can be easily dried, the boiling point of the solvent is preferably 200 ° C. or lower.
　正極用スラリー及び負極用スラリーは、上述した正極活物質又は負極活物質、固体電解質、バインダー、導電助剤、焼成助剤などと、溶媒とを混合することで作製できる。また、固体電解質用スラリーは、上述した固体電解質、バインダー、導電助剤、焼成助剤などと、溶媒とを混合することで作製できる。スラリーの混合方法は特に限定されず、必要に応じて、増粘剤、可塑剤、消泡剤、レベリング剤、密着性付与剤のような添加剤を添加してもよい。 The positive electrode slurry and the negative electrode slurry can be prepared by mixing the above-described positive electrode active material or negative electrode active material, solid electrolyte, binder, conductive auxiliary agent, baking auxiliary agent, and the like with a solvent. Moreover, the slurry for solid electrolyte can be produced by mixing the solid electrolyte, the binder, the conductive aid, the firing aid and the like described above with a solvent. The method for mixing the slurry is not particularly limited, and additives such as thickeners, plasticizers, antifoaming agents, leveling agents, and adhesion imparting agents may be added as necessary.
　正極用スラリー、負極用スラリー及び固体電解質用スラリーの塗布及び印刷方法としては、具体的には、ドクターブレード法、カレンダー法、スピンコート法、ディップコート法、インクジェット法、オフセット法、ダイコート法、スプレー法、スクリーン印刷法等を用いることができる。
　正極用スラリー、負極用スラリー及び固体電解質用スラリーの乾燥方法は、特に限定されないが、例えば、加熱乾燥、減圧乾燥、加熱減圧乾燥などを用いることができる。乾燥雰囲気は、特に限定されず、例えば、大気雰囲気下、不活性雰囲気（窒素雰囲気、アルゴン雰囲気）下で行うことができる。
　正極層グリーンシート、固体電解質層グリーンシート及び負極層グリーンシートは、順に積層された積層体グリーンシートを構成する。 Specific examples of coating and printing methods for positive electrode slurry, negative electrode slurry, and solid electrolyte slurry include a doctor blade method, a calendar method, a spin coating method, a dip coating method, an ink jet method, an offset method, a die coating method, and a spray. Method, screen printing method and the like.
Although the drying method of the slurry for positive electrodes, the slurry for negative electrodes, and the slurry for solid electrolytes is not specifically limited, For example, heat drying, reduced pressure drying, heating reduced pressure drying, etc. can be used. The drying atmosphere is not particularly limited, and can be performed, for example, in an air atmosphere or an inert atmosphere (a nitrogen atmosphere or an argon atmosphere).
The positive electrode layer green sheet, the solid electrolyte layer green sheet, and the negative electrode layer green sheet constitute a laminated green sheet that is sequentially laminated.
（１－４）全固体二次電池の製造方法
　本実施形態の全固体二次電池１は、積層体グリーンシート１０を一括焼成することで形成される。
　すなわち、本実施形態の全固体二次電池１の製造方法は、正極集電体１１上に正極層グリーンシート１２ａを形成する正極層グリーンシート形成工程と、正極層グリーンシート１２ａ上に固体電解質層グリーンシート１３ａを形成する固体電解質層グリーンシート形成工程と、固体電解質層グリーンシート１３ａ上に負極層グリーンシート１４ａを形成する負極層グリーンシート形成工程と、を含んで積層体グリーンシート１０を生成する積層体グリーンシート形成工程を備えている。また、本実施形態の全固体二次電池１の製造方法は、図３に示すように、積層体グリーンシート１０の表面に露出する負極層グリーンシート１４ａ上に、金属箔集電体からなる負極集電体１５を貼り合わせる負極集電体貼り合わせ工程と、積層体グリーンシート１０及び負極集電体１５を含む積層体１ａを焼成する焼成工程と、を備える。 (1-4) Manufacturing Method of All-Solid Secondary Battery The all-solid-state secondary battery 1 of the present embodiment is formed by firing the laminated green sheet 10 at once.
That is, the manufacturing method of the all-solid-state secondary battery 1 of this embodiment includes a positive electrode layer green sheet forming step of forming the positive electrode layer green sheet 12a on the positive electrode current collector 11, and a solid electrolyte layer on the positive electrode layer green sheet 12a. The laminate green sheet 10 is generated including a solid electrolyte layer green sheet forming step for forming the green sheet 13a and a negative electrode layer green sheet forming step for forming the negative electrode green sheet 14a on the solid electrolyte layer green sheet 13a. A laminate green sheet forming step is provided. Moreover, the manufacturing method of the all-solid-state secondary battery 1 of this embodiment is the negative electrode which consists of a metal foil collector on the negative electrode layer green sheet 14a exposed on the surface of the laminated body green sheet 10, as shown in FIG. A negative electrode current collector bonding step of bonding the current collector 15; and a baking step of baking the multilayer body 1a including the multilayer green sheet 10 and the negative electrode current collector 15.
　焼成工程における加熱温度は、積層体グリーンシート１０に含まれるバインダーの熱分解温度以上、且つ、正極活物質及び負極活物質の酸化温度未満又は金属箔集電体の燃焼温度未満の温度であることが好ましい。加熱温度は、具体的には３００℃以上１１００℃以下の範囲内が好ましく、３００℃以上９００℃以下の範囲内がより好ましい。加熱温度が３００℃より低い場合、焼成工程においてバインダーが燃焼しきらずに残渣となり、電子伝導やイオン伝導を阻害する可能性がある。また、加熱温度が１１００℃よりも高い場合、正極活物質及び負極活物質や固体電解質が溶融・変質し、電池性能を劣化させる可能性がある。
　焼成工程での雰囲気は特に限定されず、例えば、大気雰囲気下、不活性雰囲気（窒素雰囲気、アルゴン雰囲気）下で行うことができる。正極活物質及び負極活物質と金属箔集電体の反応や金属箔集電体の導電性低下が懸念される場合は、焼成工程を不活性雰囲気下で行うことが望ましい。
　焼成工程における焼成時間は、使用するバインダーが十分に分解される時間であればよく、特に限定されない。 The heating temperature in the firing step is a temperature equal to or higher than the thermal decomposition temperature of the binder contained in the laminate green sheet 10 and lower than the oxidation temperature of the positive electrode active material and the negative electrode active material or lower than the combustion temperature of the metal foil current collector. Is preferred. Specifically, the heating temperature is preferably in the range of 300 ° C. to 1100 ° C., more preferably in the range of 300 ° C. to 900 ° C. When the heating temperature is lower than 300 ° C., the binder does not completely burn out in the baking step and becomes a residue, which may hinder electronic conduction or ionic conduction. On the other hand, when the heating temperature is higher than 1100 ° C., the positive electrode active material, the negative electrode active material, and the solid electrolyte may be melted / altered to deteriorate the battery performance.
The atmosphere in the firing step is not particularly limited, and can be performed, for example, in an air atmosphere or an inert atmosphere (a nitrogen atmosphere or an argon atmosphere). When there is a concern about the reaction between the positive electrode active material and the negative electrode active material and the metal foil current collector or the decrease in conductivity of the metal foil current collector, it is desirable to perform the firing step in an inert atmosphere.
The firing time in the firing step is not particularly limited as long as the binder used is sufficiently decomposed.
　以上のように、本実施形態の全固体二次電池１は、積層体グリーンシート１０の金属箔集電体から最も離れた位置に形成される正極層グリーンシート１２ａもしくは負極層グリーンシート１４ａ上に金属箔集電体を貼り合わせた積層体１ａを一括焼成して形成することができる。すなわち、図２に示すように、積層体グリーンシート１０が正極集電体１１を備える場合、正極集電体１１から最も離れた位置に形成された負極層グリーンシート１４ａ上に、負極集電体１５を貼り合わせて一括焼成することにより、全固体二次電池１が得られる。
　これにより、正極集電体１１及び正極層１２、負極集電体１５と負極層１４との界面抵抗を抑制しつつ、１回の焼成工程で全固体二次電池１を製造することが可能となった。金属箔集電体の貼り合わせ方法は特に限定されないが、例えば平板プレス、ロールプレス、ホットプレス、冷間静水圧プレス、熱間静水圧プレスなどを用いることができる。 As described above, the all-solid-state secondary battery 1 of the present embodiment is formed on the positive electrode layer green sheet 12a or the negative electrode layer green sheet 14a formed at the position farthest from the metal foil current collector of the laminate green sheet 10. The laminated body 1a bonded with the metal foil current collector can be formed by batch firing. That is, as shown in FIG. 2, when the laminate green sheet 10 includes the positive electrode current collector 11, the negative electrode current collector is disposed on the negative electrode layer green sheet 14 a formed farthest from the positive electrode current collector 11. The all-solid-state secondary battery 1 is obtained by laminating 15 and firing together.
As a result, it is possible to manufacture the all-solid-state secondary battery 1 in a single firing step while suppressing the interface resistance between the positive electrode current collector 11 and the positive electrode layer 12, the negative electrode current collector 15 and the negative electrode layer 14. became. The method for attaching the metal foil current collector is not particularly limited, and for example, a flat plate press, a roll press, a hot press, a cold isostatic press, a hot isostatic press, or the like can be used.
（１－５）他の構成
　積層体グリーンシート１０は、金属箔集電体と、金属箔集電体上に設けられた第１電極層グリーンシートと、第１電極層グリーンシート上に設けられた固体電解質層グリーンシートと、固体電解質層グリーンシート上に設けられた第２電極層グリーンシートと、を少なくとも備えていればよい。
　このため、積層体グリーンシート１０は、上述した構成以外にも、負極集電体１５と、負極集電体１５上に設けられた負極層グリーンシート１４ａと、負極層グリーンシート１４ａ上に設けられた固体電解質層グリーンシート１３ａと、固体電解質層グリーンシート１３ａ上に設けられた正極層グリーンシート１２ａと、を備えた構成であってもよい。 (1-5) Other Configurations The laminate green sheet 10 is provided on the metal foil current collector, the first electrode layer green sheet provided on the metal foil current collector, and the first electrode layer green sheet. The solid electrolyte layer green sheet and the second electrode layer green sheet provided on the solid electrolyte layer green sheet may be provided.
Therefore, the laminate green sheet 10 is provided on the negative electrode current collector 15, the negative electrode layer green sheet 14a provided on the negative electrode current collector 15, and the negative electrode layer green sheet 14a in addition to the configuration described above. The solid electrolyte layer green sheet 13a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be used.
　この場合、負極集電体１５上に、負極活物質を含む負極用スラリーを塗布又は印刷したのち乾燥して負極層グリーンシート１４ａを形成し、負極層グリーンシート１４ａ上に固体電解質材料を含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシート１３ａを形成し、固体電解質層グリーンシート１３ａ上に正極活物質を含む正極用スラリーを塗布又は印刷したのち乾燥して正極層グリーンシート１２ａを形成して積層体グリーンシート１０が形成される。そして、固体電解質層グリーンシート１３ａに含まれるバインダーの分解しやすさは、負極層グリーンシート１４ａに含まれるバインダーの分解しやすさと同等か又は負極層グリーンシート１４ａの分解しやすさよりも大きい。また、正極層グリーンシート１２ａに含まれるバインダーの分解しやすさは、負極層グリーンシート１４ａに含まれるバインダーの分解しやすさよりも大きく、かつ固体電解質層グリーンシート１３ａに含まれるバインダーの分解しやすさと同等か又は固体電解質層グリーンシート１３ａに含まれるバインダーの分解しやすさよりも大きい。 In this case, a negative electrode slurry containing a negative electrode active material is applied or printed on the negative electrode current collector 15 and then dried to form a negative electrode layer green sheet 14a. A solid containing a solid electrolyte material on the negative electrode layer green sheet 14a The electrolyte slurry is applied or printed and then dried to form the solid electrolyte layer green sheet 13a. The positive electrode slurry containing the positive electrode active material is applied or printed on the solid electrolyte layer green sheet 13a and then dried to form the positive electrode layer green. The laminated body green sheet 10 is formed by forming the sheet 12a. And the ease of decomposition | disassembly of the binder contained in the solid electrolyte layer green sheet 13a is equal to the ease of decomposition | disassembly of the binder contained in the negative electrode layer green sheet 14a, or larger than the ease of decomposition | disassembly of the negative electrode layer green sheet 14a. Further, the easiness of decomposition of the binder contained in the positive electrode layer green sheet 12a is greater than the easiness of decomposition of the binder contained in the negative electrode layer green sheet 14a, and the easiness of decomposition of the binder contained in the solid electrolyte layer green sheet 13a. Or greater than the ease of decomposition of the binder contained in the solid electrolyte layer green sheet 13a.
　また、全固体二次電池１は、上述のようにして作製した積層体グリーンシートの表面に露出する正極層グリーンシート１２ａ上に正極集電体１１を貼り合わせた積層体を焼成することにより得られる。 Moreover, the all-solid-state secondary battery 1 is obtained by baking the laminated body which bonded the positive electrode electrical power collector 11 on the positive electrode layer green sheet 12a exposed on the surface of the laminated body green sheet produced as mentioned above. It is done.
２．第２の実施形態
　第２の実施形態では、本発明に係る積層型の全固体二次電池（直列全固体二次電池）及び全固体二次電池の製造方法について説明する。また、以下の第２の実施形態において、本発明に係る全固体二次電池の製造に用いられる連続積層体グリーンシート及び連続積層体グリーンシートの製造方法について説明する。
　また、第２の実施形態の全固体二次電池が、第１の実施形態で説明した全固体二次電池１と同様の構成を有する場合には共通の参照符号を用いて説明する。 2. Second Embodiment In the second embodiment, a stacked-type all-solid secondary battery (series all-solid secondary battery) and an all-solid secondary battery manufacturing method according to the present invention will be described. Moreover, in the following 2nd Embodiment, the manufacturing method of the continuous laminated body green sheet used for manufacture of the all-solid-state secondary battery which concerns on this invention, and a continuous laminated body green sheet is demonstrated.
Moreover, when the all-solid-state secondary battery of 2nd Embodiment has the structure similar to the all-solid-state secondary battery 1 demonstrated in 1st Embodiment, it demonstrates using a common referential mark.
（２－１）直列全固体二次電池の構成
［直列全固体二次電池の構成］ (2-1) Configuration of series all solid state secondary battery [Configuration of series all solid state secondary battery]
　図４に示すように、第２の実施形態における直列全固体二次電池（以下、全固体二次電池と記載する）２１は、正極層１２、正極層１２上に設けられた固体電解質層１３、及び固体電解質層１３上に設けられた負極層１４、を備える複数の電極積層体２０を備えている。また、全固体二次電池２１は、積層された複数の電極積層体２０同士の間及び積層された複数の電極積層体２０の積層方向外面のさらに外側に、正極層１２又は負極層１４と密着して設けられた、複数の金属箔集電体（正極集電体１１又は負極集電体１５）を備えている。この構成は、後に詳細に説明するように、正極層グリーンシート１２ａ、固体電解質層グリーンシート１３ａ及び負極層グリーンシート１４ａを積層した積層体グリーンシートが正極集電体１１を介して複数積層され、正極集電体１１及び負極集電体１５で外面を挟持された状態で一括焼成を行うという全固体二次電池２１の製造方法により実現される。 As shown in FIG. 4, a series all solid state secondary battery (hereinafter referred to as an all solid state secondary battery) 21 in the second embodiment includes a positive electrode layer 12 and a solid electrolyte layer 13 provided on the positive electrode layer 12. , And a negative electrode layer 14 provided on the solid electrolyte layer 13. In addition, the all-solid-state secondary battery 21 is in close contact with the positive electrode layer 12 or the negative electrode layer 14 between the stacked electrode stacks 20 and on the outer side in the stacking direction of the stacked electrode stacks 20. And provided with a plurality of metal foil current collectors (positive electrode current collector 11 or negative electrode current collector 15). In this configuration, as will be described in detail later, a plurality of stacked green sheets each including a positive electrode layer green sheet 12a, a solid electrolyte layer green sheet 13a, and a negative electrode layer green sheet 14a are stacked via the positive electrode current collector 11, This is realized by the manufacturing method of the all-solid-state secondary battery 21 in which batch firing is performed with the outer surface sandwiched between the positive electrode current collector 11 and the negative electrode current collector 15.
　正極層１２、固体電解質層１３及び負極層１４、並びに正極集電体１１又は負極集電体１５は、第１の実施形態の正極層１２、固体電解質層１３及び負極層１４、並びに正極集電体１１又は負極集電体１５と同様であるため、説明を省略する。 The positive electrode layer 12, the solid electrolyte layer 13 and the negative electrode layer 14, and the positive electrode current collector 11 or the negative electrode current collector 15 are the positive electrode layer 12, the solid electrolyte layer 13 and the negative electrode layer 14, and the positive electrode current collector of the first embodiment. Since it is the same as that of the body 11 or the negative electrode current collector 15, the description thereof is omitted.
（２－２）連続積層体グリーンシートの構成
　以下、連続積層体グリーンシートについて説明する。
［積層体グリーンシートの構成］
　図５に示すように、第２の実施形態における連続積層体グリーンシート３０は、金属箔集電体からなる正極集電体１１と、正極集電体１１上に設けられた正極層グリーンシート１２ａと、正極層グリーンシート１２ａ上に設けられた固体電解質層グリーンシート１３ａと、固体電解質層グリーンシート１３ａ上に設けられた負極層グリーンシート１４ａと、を備える積層体グリーンシート１０（１０ａ～１０ｅ）が連続的に積層されている。
　正極層グリーンシート１２ａ、固体電解質層グリーンシート１３ａ及び負極層グリーンシート１４ａは、第１の実施形態の積層体グリーンシート１０の正極層グリーンシート１２ａ、固体電解質層グリーンシート１３ａ及び負極層グリーンシート１４ａと同様であるため、説明を省略する。また、各層に含まれるバインダーについても、第１の実施形態で説明したバインダーと同様であるため、説明を省略する。 (2-2) Configuration of Continuous Laminated Green Sheet Hereinafter, the continuous laminated green sheet will be described.
[Configuration of laminated green sheet]
As shown in FIG. 5, the continuous laminate green sheet 30 in the second embodiment includes a positive electrode current collector 11 made of a metal foil current collector, and a positive electrode layer green sheet 12 a provided on the positive electrode current collector 11. A laminated green sheet 10 (10a to 10e), comprising: a solid electrolyte layer green sheet 13a provided on the positive electrode layer green sheet 12a; and a negative electrode layer green sheet 14a provided on the solid electrolyte layer green sheet 13a. Are continuously laminated.
The positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a are the positive electrode layer green sheet 12a, the solid electrolyte layer green sheet 13a, and the negative electrode layer green sheet 14a of the multilayer green sheet 10 of the first embodiment. Since it is the same as that of FIG. Moreover, since the binder contained in each layer is the same as the binder described in the first embodiment, the description thereof is omitted.
（２－３）連続積層体グリーンシートの製造方法
　以下、連続積層体グリーンシート３０及び全固体二次電池２１の製造方法について説明する。
　連続積層体グリーンシート３０の製造方法は、金属箔集電体からなる正極集電体１１上に、正極活物質を含む正極用スラリーを塗布又は印刷したのち乾燥して正極層グリーンシート１２ａを形成する正極層グリーンシート形成工程と、正極層グリーンシート１２ａ上に固体電解質を含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシート１３ａを形成する固体電解質層グリーンシート形成工程と、固体電解質層グリーンシート１３ａ上に、負極活物質を含む負極用スラリーを塗布又は印刷したのち乾燥して負極層グリーンシート１４ａを形成する負極層グリーンシート形成工程とにより積層体グリーンシート１０（１０ａ～１０ｅ）を形成する。また、連続積層体グリーンシート３０の製造方法は、図２に示すように、積層体グリーンシート１０（１０ａ～１０ｅ）を、複数連続的に積層するグリーンシート積層工程と、を備えている。 (2-3) Manufacturing Method of Continuous Laminate Green Sheet Hereinafter, a manufacturing method of the continuous laminate green sheet 30 and the all-solid secondary battery 21 will be described.
The method for producing the continuous laminate green sheet 30 is to apply or print a positive electrode slurry containing a positive electrode active material on the positive electrode current collector 11 made of a metal foil current collector, and then dry to form the positive electrode layer green sheet 12a. A positive electrode layer green sheet forming step, a solid electrolyte layer green sheet forming step of forming a solid electrolyte layer green sheet 13a by applying or printing a solid electrolyte slurry containing a solid electrolyte on the positive electrode layer green sheet 12a and then drying the solid electrolyte layer green sheet 13a; The negative electrode layer green sheet forming step of forming the negative electrode layer green sheet 14a by applying or printing the negative electrode slurry containing the negative electrode active material on the solid electrolyte layer green sheet 13a and then drying the laminate green sheet 10 (10a To 10e). Further, as shown in FIG. 2, the manufacturing method of the continuous laminate green sheet 30 includes a green sheet lamination step of continuously laminating a plurality of laminate green sheets 10 (10a to 10e).
　連続積層体グリーンシート３０は、例えば、複数個の積層体グリーンシート１０（１０ａ～１０ｅ）のうち、一の積層体グリーンシート１０（例えば積層体グリーンシート１０ｂ）の正極集電体１１側と他の積層体グリーンシート１０（例えば積層体グリーンシート１０ａ）の負極層グリーンシート１４ａとを隣接するように貼り合わせて形成される。積層体グリーンシート１０同士の貼り合わせ方法は特に限定されず、例えば平板プレス、ロールプレス、ホットプレス、冷間静水圧プレス、熱間静水圧プレスなどを用いることができる。 The continuous laminate green sheet 30 is, for example, the positive electrode current collector 11 side of one laminate green sheet 10 (eg, laminate green sheet 10b) among the plurality of laminate green sheets 10 (10a to 10e) and the other. The laminated green sheet 10 (for example, the laminated green sheet 10a) is bonded to the negative electrode layer green sheet 14a so as to be adjacent to each other. The method for laminating the laminate green sheets 10 is not particularly limited, and for example, a flat plate press, a roll press, a hot press, a cold isostatic press, a hot isostatic press, or the like can be used.
（２－４）直列全固体二次電池の製造方法
　第２の実施形態の全固体二次電池２１は、連続積層体グリーンシート３０からバインダーを脱脂し、焼成することで形成される。
　すなわち、本実施形態の全固体二次電池２１の製造方法は、金属箔集電体からなる正極集電体１１上に、正極活物質を含む正極用スラリーを塗布又は印刷したのち乾燥して正極層グリーンシート１２ａを形成する正極層グリーンシート形成工程、正極層グリーンシート１２ａ上に、固体電解質を含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシート１３ａを形成する固体電解質層グリーンシート形成工程、及び固体電解質層グリーンシート１３ａ上に、負極活物質を含む負極用スラリーを塗布又は印刷したのち乾燥して負極層グリーンシート１４ａを形成する負極層グリーンシート形成工程を含んで積層体グリーンシート１０（１０ａ～１０ｅ）を形成する積層体グリーンシート形成工程を備えている。
　また、本実施形態の全固体二次電池２１の製造方法は、積層体グリーンシート１０（１０ａ～１０ｅ）を複数積層して連続積層体グリーンシート３０を形成する連続積層体グリーンシート形成工程と、図６に示すように、連続積層体グリーンシート３０の表面に露出する負極層グリーンシート１４ａ上に、金属箔集電体からなる負極集電体１５を貼り合わせる負極集電体貼り合わせ工程と、連続積層体グリーンシート３０及び負極集電体１５を含む積層体２１ａを焼成する焼成工程と、を備えている。 (2-4) Manufacturing Method of Series All-Solid Secondary Battery The all-solid-state secondary battery 21 of the second embodiment is formed by degreasing the binder from the continuous laminate green sheet 30 and firing it.
That is, the manufacturing method of the all-solid-state secondary battery 21 of the present embodiment is such that a positive electrode slurry containing a positive electrode active material is applied or printed on a positive electrode current collector 11 made of a metal foil current collector, and then dried. Step of forming positive electrode layer green sheet 12a for forming green layer 12a, solid electrolyte for forming solid electrolyte layer green sheet 13a by applying or printing slurry for solid electrolyte containing solid electrolyte on positive electrode layer green sheet 12a and drying And a negative electrode layer green sheet forming step of forming a negative electrode layer green sheet 14a by applying or printing a negative electrode slurry containing a negative electrode active material on the solid electrolyte layer green sheet 13a and then drying it. A laminate green sheet forming step for forming the laminate green sheet 10 (10a to 10e) is provided.
In addition, the method for manufacturing the all-solid-state secondary battery 21 of the present embodiment includes a continuous laminate green sheet forming step in which a plurality of laminate green sheets 10 (10a to 10e) are laminated to form a continuous laminate green sheet 30; As shown in FIG. 6, a negative electrode current collector bonding step of bonding a negative electrode current collector 15 made of a metal foil current collector on the negative electrode layer green sheet 14 a exposed on the surface of the continuous laminate green sheet 30; And a firing step of firing the laminate 21 a including the continuous laminate green sheet 30 and the negative electrode current collector 15.
　第２の実施形態の焼成工程における加熱温度、金属箔集電体の貼り合わせ方法などは、第１の実施形態と同様であるため説明を省略する。 The heating temperature in the firing step of the second embodiment, the method for attaching the metal foil current collector, and the like are the same as those of the first embodiment, and thus the description thereof is omitted.
　以上のように、第２の実施形態の全固体二次電池２１は、連続積層体グリーンシート３０の金属箔集電体から最も離れた位置に形成される電極層グリーンシート（正極層グリーンシート１２ａもしくは負極層グリーンシート１４ａ）上に金属箔集電体を貼り合わせた積層体２１ａを一括焼成して形成することができる。すなわち、連続積層体グリーンシート３０が正極集電体１１を備える場合、正極集電体１１から最も離れた位置に形成された負極層グリーンシート１４ａ上に、負極集電体１５を貼り合わせて一括焼成することにより、全固体二次電池２１が得られる。
　これにより、正極集電体１１及び正極層１２、負極集電体１５と負極層１４との界面抵抗を抑制しつつ、１回の焼成工程で全固体二次電池２１を製造することが可能となった。 As described above, the all-solid-state secondary battery 21 of the second embodiment includes the electrode layer green sheet (positive electrode layer green sheet 12a) formed at the position farthest from the metal foil current collector of the continuous laminate green sheet 30. Or the laminated body 21a which bonded the metal foil electrical power collector on the negative electrode layer green sheet 14a) can be formed by baking collectively. That is, when the continuous laminate green sheet 30 includes the positive electrode current collector 11, the negative electrode current collector 15 is bonded together on the negative electrode layer green sheet 14 a formed farthest from the positive electrode current collector 11. By firing, the all-solid-state secondary battery 21 is obtained.
As a result, it is possible to manufacture the all-solid-state secondary battery 21 in one firing step while suppressing the interface resistance between the positive electrode current collector 11 and the positive electrode layer 12, the negative electrode current collector 15 and the negative electrode layer 14. became.
（２－５）他の構成
　第１の実施形態に記載したように、積層体グリーンシート１０は、金属箔集電体と、金属箔集電体上に設けられた第１電極層グリーンシートと、第１電極層グリーンシート上に設けられた固体電解質層グリーンシートと、固体電解質層グリーンシート上に設けられた第２電極層グリーンシートと、を少なくとも備えていればよい。
　このため、積層体グリーンシート１０は、上述した構成以外にも、負極集電体１５と、負極集電体１５上に設けられた負極層グリーンシート１４ａと、負極層グリーンシート１４ａ上に設けられた固体電解質層グリーンシート１３ａと、固体電解質層グリーンシート１３ａ上に設けられた正極層グリーンシート１２ａと、を備えた構成であってもよい。 (2-5) Other Configurations As described in the first embodiment, the laminate green sheet 10 includes a metal foil current collector, and a first electrode layer green sheet provided on the metal foil current collector. The solid electrolyte layer green sheet provided on the first electrode layer green sheet and the second electrode layer green sheet provided on the solid electrolyte layer green sheet may be provided at least.
Therefore, the laminate green sheet 10 is provided on the negative electrode current collector 15, the negative electrode layer green sheet 14a provided on the negative electrode current collector 15, and the negative electrode layer green sheet 14a in addition to the configuration described above. The solid electrolyte layer green sheet 13a and the positive electrode layer green sheet 12a provided on the solid electrolyte layer green sheet 13a may be used.
　この場合、負極集電体１５上に、負極活物質を含む負極用スラリーを塗布又は印刷したのち乾燥して負極層グリーンシート１４ａを形成し、負極層グリーンシート１４ａ上に固体電解質材料を含む固体電解質用スラリーを塗布又は印刷したのち乾燥して固体電解質層グリーンシート１３ａを形成し、固体電解質層グリーンシート１３ａ上に正極活物質を含む正極用スラリーを塗布又は印刷したのち乾燥して正極層グリーンシート１２ａを形成して積層体グリーンシートが形成される。
　また、全固体二次電池２１は、上述のようにして作製した積層体グリーンシートを連続的に積層し、この連続積層体グリーンシートの表面に露出する正極層グリーンシート１２ａ上に正極集電体１１を貼り合わせた積層体を焼成することにより得られる。 In this case, a negative electrode slurry containing a negative electrode active material is applied or printed on the negative electrode current collector 15 and then dried to form a negative electrode layer green sheet 14a. A solid containing a solid electrolyte material on the negative electrode layer green sheet 14a The electrolyte slurry is applied or printed and then dried to form the solid electrolyte layer green sheet 13a. The positive electrode slurry containing the positive electrode active material is applied or printed on the solid electrolyte layer green sheet 13a and then dried to form the positive electrode layer green. A sheet green is formed by forming the sheet 12a.
In addition, the all-solid-state secondary battery 21 is formed by continuously laminating the laminated green sheets produced as described above, and the positive electrode current collector on the positive electrode layer green sheet 12a exposed on the surface of the continuous laminated green sheet. 11 is obtained by firing the laminated body to which 11 is bonded.
［実施例］
　以下に、本実施形態で説明した全固体二次電池に関して、具体的な実施例及び比較例を挙げて説明する。なお、本発明に係る全固体二次電池の構成は、以下の実施例によって制限されるものではない。 [Example]
The all solid state secondary battery described in the present embodiment will be described below with specific examples and comparative examples. In addition, the structure of the all-solid-state secondary battery which concerns on this invention is not restrict | limited by a following example.
＜熱重量減少ピーク温度の測定＞
　まず、以下の各実施例及び比較例の積層体グリーンシートの第１の活物質層、固体電解質層、及び第２の活物質層の各層に用いる各バインダー（ポリビニルブチラール（ＰＶＢ）樹脂、アクリル樹脂Ａ及びアクリル樹脂Ｂ）の熱重量減少ピーク温度を測定した。熱重量減少ピーク温度は、熱重量測定装置を使用し、窒素気流中、昇温速度１００℃／ｍｉｎで室温から７００℃まで昇温して測定を行った。
　測定の結果、ポリビニルブチラール（ＰＶＢ）樹脂の熱重量減少ピーク温度は４００℃であった。また、アクリル樹脂Ａの熱重量減少ピーク温度は３８０℃であった。さらに、アクリル樹脂Ｂの熱重量減少ピーク温度は３３０℃であった。
　このようなバインダーを用いて、以下の各実施例及び比較例の全固体二次電池を作製した。 <Measurement of thermogravimetric decrease peak temperature>
First, each binder (polyvinyl butyral (PVB) resin, acrylic resin) used for each of the first active material layer, the solid electrolyte layer, and the second active material layer of the laminate green sheet of each of the following Examples and Comparative Examples The thermogravimetric decrease peak temperatures of A and acrylic resin B) were measured. The thermogravimetric decrease peak temperature was measured by using a thermogravimetric measuring device and raising the temperature from room temperature to 700 ° C. at a rate of temperature rise of 100 ° C./min in a nitrogen stream.
As a result of the measurement, the thermogravimetric decrease peak temperature of the polyvinyl butyral (PVB) resin was 400 ° C. Moreover, the thermogravimetric decrease peak temperature of the acrylic resin A was 380 ° C. Furthermore, the thermogravimetric decrease peak temperature of the acrylic resin B was 330 ° C.
Using such a binder, all-solid secondary batteries of the following examples and comparative examples were produced.
（実施例１）
［スラリー作製工程］
＜正極用スラリーの作製＞
　正極活物質としてコバルト酸リチウム（ＬｉＣｏＯ２）粉末５０重量部、固体電解質としてＬｉ１．５Ａｌ０．５Ｇｅ１．５（ＰＯ４）３（以下、ＬＡＧＰとも記載する）粉末５０重量部、導電助剤としてアセチレンブラック２０重量部、バインダーとしてポリビニルブチラール（ＰＶＢ）樹脂１６重量部を、溶剤であるターピネオールに混合してスラリーとし、このスラリーを脱泡して正極用スラリーを作製した。 Example 1
[Slurry preparation process]
<Preparation of slurry for positive electrode>
50 parts by weight of lithium cobaltate (LiCoO 2 ) powder as a positive electrode active material, 50 parts by weight of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (hereinafter also referred to as LAGP) powder as a solid electrolyte, conductive 20 parts by weight of acetylene black as an auxiliary agent and 16 parts by weight of polyvinyl butyral (PVB) resin as a binder were mixed with terpineol as a solvent to form a slurry, and the slurry was defoamed to prepare a positive electrode slurry.
＜固体電解質用スラリーの作製＞
　固体電解質としてＬＡＧＰ粉末１００重量部、バインダーとしてアクリル樹脂Ａ１６重量部を、溶剤であるターピネオールに混合してスラリーとし、このスラリーを脱泡して固体電解質用スラリーを作製した。 <Preparation of slurry for solid electrolyte>
100 parts by weight of LAGP powder as a solid electrolyte and 16 parts by weight of acrylic resin A as a binder were mixed with terpineol as a solvent to form a slurry, and this slurry was defoamed to prepare a solid electrolyte slurry.
＜負極用スラリーの作製＞
　負極活物質としてチタン酸リチウム（Ｌｉ４Ｔｉ５Ｏ１２）粉末５０重量部、固体電解質としてＬＡＧＰ粉末５０重量部、導電助剤としてグラファイト２０重量部、バインダーとしてアクリル樹脂Ｂ１６重量部を、溶剤であるターピネオールに混合してスラリーとし、このスラリーを脱泡して負極用スラリーを作製した。 <Preparation of slurry for negative electrode>
50 parts by weight of lithium titanate (Li 4 Ti 5 O 12 ) powder as a negative electrode active material, 50 parts by weight of LAGP powder as a solid electrolyte, 20 parts by weight of graphite as a conductive additive, and 16 parts by weight of acrylic resin B as a binder are solvents. The slurry was mixed with terpineol, and the slurry was defoamed to prepare a negative electrode slurry.
＜積層体グリーンシート作製工程＞
　正極集電体として厚さ２０μｍのステンレス製の金属集電箔を使用した。この集電箔の一方の面に、第１の活物質スラリーとして正極用スラリーを塗布、乾燥し、第１の活物質層である正極層グリーンシートを作製した。
　続いて、正極層グリーンシートの金属集電箔対向面とは反対側の面上に、固体電解質用スラリーを塗布、乾燥し、固体電解質層グリーンシートを作製した。
　最後に、固体電解質層グリーンシートの正極層グリーンシート対向面とは反対側の面上に、第２の活物質スラリーとして負極用スラリーを塗布、乾燥し、第２の活物質層である負極層グリーンシートを作製した。これにより、図２に示すような積層体グリーンシートを作製した。 <Laminated green sheet production process>
A stainless steel metal current collector foil with a thickness of 20 μm was used as the positive electrode current collector. A positive electrode slurry as a first active material slurry was applied to one surface of the current collector foil and dried to prepare a positive electrode layer green sheet as a first active material layer.
Subsequently, the solid electrolyte slurry was applied on the surface of the positive electrode layer green sheet opposite to the surface facing the metal current collector foil and dried to prepare a solid electrolyte layer green sheet.
Finally, a negative electrode slurry as a second active material slurry is applied and dried on the surface of the solid electrolyte layer green sheet opposite to the positive electrode layer facing the green sheet, and the negative electrode layer as the second active material layer A green sheet was produced. Thereby, the laminated body green sheet as shown in FIG. 2 was produced.
＜切断工程＞
　作製した積層体グリーンシートの負極層グリーンシート上に、正極集電体と同様の厚さ２０μｍの金属集電箔からなる負極集電体に貼り合わせた。続いて、負極集電体を貼り合わせた積層体グリーンシートからなる積層体を８０℃、１０００ｋｇｆ／ｃｍ２（９８ＭＰａ）で加圧した。この後、正極集電体及び負極集電体が、積層体のそれぞれ異なる面で露出するように個々の要素に切断した。 <Cutting process>
On the negative electrode layer green sheet of the produced laminate green sheet, a negative electrode current collector made of a metal current collector foil having a thickness of 20 μm similar to the positive electrode current collector was bonded. Then, the laminated body which consists of a laminated body green sheet which bonded the negative electrode collector was pressurized at 80 degreeC and 1000 kgf / cm < 2 > (98 MPa). Thereafter, the positive electrode current collector and the negative electrode current collector were cut into individual elements so as to be exposed on different surfaces of the laminate.
＜焼成工程＞
　個々の要素に切断した積層体を、窒素気流中、昇温速度１００℃／ｍｉｎで室温から７００℃まで昇温し、その温度で３０分間保持し焼成を実施した。その後、積層体を炉内放冷で室温まで冷却し、図１に示すような実施例１の全固体二次電池を作製した。
　なお、実施例１に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（アクリル樹脂Ａ）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たした。 <Baking process>
The laminate cut into individual elements was heated from room temperature to 700 ° C. at a temperature rising rate of 100 ° C./min in a nitrogen stream, and held at that temperature for 30 minutes for firing. Thereafter, the laminate was allowed to cool to room temperature in a furnace, and an all-solid secondary battery of Example 1 as shown in FIG. 1 was produced.
In the binder used in Example 1, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin A) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta were satisfied.
（実施例２）
　作製した積層体グリーンシートの負極層グリーンシート上に負極集電体の貼り合わせを行わず、また切断を行わない以外は実施例１と同様にして積層焼成体を作製した。作製された積層焼成体の負極層上に、厚さ２０μｍのステンレス製の金属集電箔からなる負極集電体を貼り合わせた。負極集電体を貼り合わせた積層焼成体を８０℃、１０００ｋｇｆ／ｃｍ２（９８ＭＰａ）で加圧した。この後、正極集電体及び負極集電体が、積層焼成体のそれぞれ異なる面で露出するように個々の要素に切断して、図１に示すような実施例２の全固体二次電池を作製した。
　なお、実施例２に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（アクリル樹脂Ａ）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たした。 (Example 2)
A laminated fired body was produced in the same manner as in Example 1 except that the negative electrode current collector was not bonded to the negative electrode layer green sheet of the produced laminated green sheet and was not cut. A negative electrode current collector made of a stainless steel metal current collector foil having a thickness of 20 μm was bonded onto the negative electrode layer of the produced laminated fired body. The laminated fired body on which the negative electrode current collector was bonded was pressed at 80 ° C. and 1000 kgf / cm 2 (98 MPa). Thereafter, the positive electrode current collector and the negative electrode current collector are cut into individual elements so as to be exposed on different surfaces of the laminated fired body, and the all-solid-state secondary battery of Example 2 as shown in FIG. Produced.
In the binder used in Example 2, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin A) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta were satisfied.
（実施例３)
　固体電解質用スラリーに混合するバインダーをアクリル樹脂Ｂとした以外は実施例１と同様にして、図１に示すような実施例３の全固体二次電池を作製した。
　なお、実施例３に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たした。 (Example 3)
An all-solid secondary battery of Example 3 as shown in FIG. 1 was produced in the same manner as in Example 1 except that acrylic resin B was used as the binder to be mixed in the solid electrolyte slurry.
In the binder used in Example 3, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin B) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta were satisfied.
（実施例４）
　固体電解質用スラリーに混合するバインダーをＰＶＢ樹脂とした以外は実施例１と同様にして、図１に示すような実施例４の全固体二次電池を作製した。
　なお、実施例４に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たした。 (Example 4)
An all-solid secondary battery of Example 4 as shown in FIG. 1 was produced in the same manner as in Example 1 except that the binder mixed in the solid electrolyte slurry was PVB resin.
In the binder used in Example 4, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer, the thermogravimetric decrease peak of the binder (PVB resin) contained in the solid electrolyte layer. Regarding the temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta were satisfied.
（実施例５）
＜連続積層体グリーンシート作製工程＞
　実施例１と同様にして作製した積層体グリーンシートを所定の大きさに切断して積層体を作製した。この積層体を５個作製した。続いて、５個の積層体を順に積層し、図５に示すような連続積層体グリーンシートを形成した。最後に、金属集電箔と接していない負極層グリーンシート上に、正極集電体と同様の厚さ２０μｍのステンレス製の金属集電箔からなる負極集電体を乗せて図６に示すような連続積層体を得た。続いて、この連続積層体を、全体を８０℃、１０００ｋｇｆ／ｃｍ２（９８ＭＰａ）で加圧した。 (Example 5)
<Continuous laminate green sheet production process>
A laminate green sheet produced in the same manner as in Example 1 was cut into a predetermined size to produce a laminate. Five laminates were produced. Subsequently, five laminates were sequentially laminated to form a continuous laminate green sheet as shown in FIG. Finally, on the negative electrode layer green sheet not in contact with the metal current collector foil, a negative electrode current collector made of stainless steel metal current collector foil having a thickness of 20 μm similar to the positive electrode current collector is placed, as shown in FIG. A continuous laminate was obtained. Subsequently, the whole continuous laminate was pressurized at 80 ° C. and 1000 kgf / cm 2 (98 MPa).
＜焼成工程＞
　連続積層体を、窒素気流中、昇温速度８０℃／ｍｉｎで室温から７００℃まで昇温し、その温度で３０分間保持した後、炉内放冷で室温まで冷却し、図４に示すような連続積層焼成体である実施例５の直列全固体二次電池を作製した。
　なお、実施例５に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（アクリル樹脂Ａ）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たした。 <Baking process>
The continuous laminate was heated from room temperature to 700 ° C. in a nitrogen stream at a heating rate of 80 ° C./min, held at that temperature for 30 minutes, then cooled to room temperature by standing in the furnace, as shown in FIG. A serial all-solid secondary battery of Example 5 which is a continuous laminated fired body was produced.
In the binder used in Example 5, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin A) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin B) contained in the second active material layer, both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta were satisfied.
（比較例１）
　第１の活物質スラリーである正極用スラリーに混合するバインダーをアクリル樹脂Ｂとし、固体電解質用スラリーに混合するバインダーをＰＶＢ樹脂とし、第２の活物質スラリーである負極用スラリーに混合するバインダーをアクリル樹脂Ａとした以外は、実施例１と同様にして比較例１の全固体二次電池を作製した。
　なお、比較例１に用いるバインダーでは、第１の活物質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ａ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦Ｔａ及びＴｂ＜Ｔａの双方を満たさなかった。 (Comparative Example 1)
The binder mixed with the positive electrode slurry, which is the first active material slurry, is acrylic resin B, the binder mixed with the solid electrolyte slurry is the PVB resin, and the binder mixed with the negative electrode slurry, which is the second active material slurry, An all-solid secondary battery of Comparative Example 1 was produced in the same manner as in Example 1 except that the acrylic resin A was used.
In the binder used in Comparative Example 1, the thermogravimetric decrease peak temperature (Ta) of the binder (acrylic resin B) contained in the first active material layer and the thermogravimetric decrease of the binder (PVB resin) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin A) contained in the second active material layer, both Tb ≦ Tse ≦ Ta and Tb <Ta were not satisfied.
（比較例２）
　第１の活物質スラリーである正極用スラリーに混合するバインダーをＰＶＢ樹脂とし、固体電解質用スラリーに混合するバインダーをアクリル樹脂Ｂとし、第２の活物質スラリーである負極用スラリーに混合するバインダーをアクリル樹脂Ａとした以外は、実施例１と同様にして比較例２の全固体二次電池を作製した。
　なお、比較例２に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（アクリル樹脂Ｂ）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（アクリル樹脂Ａ）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦Ｔａの条件を満たさないものの、Ｔｂ＜Ｔａの条件を満たした。 (Comparative Example 2)
The binder mixed with the positive electrode slurry, which is the first active material slurry, is PVB resin, the binder mixed with the solid electrolyte slurry is acrylic resin B, and the binder mixed with the negative electrode slurry, which is the second active material slurry, An all-solid secondary battery of Comparative Example 2 was produced in the same manner as in Example 1 except that the acrylic resin A was used.
In the binder used in Comparative Example 2, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease of the binder (acrylic resin B) contained in the solid electrolyte layer. Regarding the peak temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (acrylic resin A) contained in the second active material layer, the condition of Tb ≦ Tse ≦ Ta is satisfied, but the condition of Tb <Ta is satisfied. Satisfied.
（比較例３）
第１の活物質スラリーである正極用スラリー、固体電解質用スラリー及び第２の活物質スラリーである負極用スラリーに混合するバインダーを全てＰＶＢ樹脂とした以外は、実施例１と同様にして比較例３の全固体二次電池を作製した。
　なお、比較例３に用いるバインダーでは、第１の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔａ）、固体電解質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔｓｅ）及び第２の活物質層に含まれるバインダー（ＰＶＢ樹脂）の熱重量減少ピーク温度（Ｔｂ）について、Ｔｂ≦Ｔｓｅ≦Ｔａの条件は満たすものの、Ｔｂ＜Ｔａの条件は満たさなかった。 (Comparative Example 3)
Comparative Example as in Example 1 except that the binder mixed in the first active material slurry, the positive electrode slurry, the solid electrolyte slurry, and the second active material slurry, the negative electrode slurry was all PVB resin. 3 all-solid-state secondary batteries were produced.
In the binder used in Comparative Example 3, the thermogravimetric decrease peak temperature (Ta) of the binder (PVB resin) contained in the first active material layer and the thermogravimetric decrease peak of the binder (PVB resin) contained in the solid electrolyte layer. Regarding the temperature (Tse) and the thermogravimetric decrease peak temperature (Tb) of the binder (PVB resin) contained in the second active material layer, the condition of Tb ≦ Tse ≦ Ta was satisfied, but the condition of Tb <Ta was not satisfied. .
［電気化学評価］
　以下のようにして、作製した全固体二次電池及び直列全固体二次電池について電気化学評価を行った。
（実施例１から実施例４、比較例１から比較例３の全固体二次電池の評価方法）
　各実施例及び比較例の全固体二次電池を１０個ずつ準備し、評価を行った。
　各実施例及び比較例の全固体二次電池を０.２Ｃの定電流によって電圧が２．７Ｖとなるまで充電した後、０．２Ｃの定電流にて電圧１．５Ｖまで放電した。このときの放電容量（０．２Ｃ放電容量）を基準容量Ａとした。基準容量Ａは１０個の全固体二次電池の放電容量の平均値とした。 [Electrochemical evaluation]
The electrochemical evaluation was performed about the produced all-solid-state secondary battery and series all-solid-state secondary battery as follows.
(Evaluation method for all-solid-state secondary batteries of Examples 1 to 4 and Comparative Examples 1 to 3)
Ten all solid state secondary batteries of each Example and Comparative Example were prepared and evaluated.
The all solid state secondary batteries of Examples and Comparative Examples were charged with a constant current of 0.2 C until the voltage reached 2.7 V, and then discharged with a constant current of 0.2 C to a voltage of 1.5 V. The discharge capacity (0.2 C discharge capacity) at this time was defined as the reference capacity A. The reference capacity A was an average value of discharge capacities of ten all solid state secondary batteries.
　次に、各実施例及び比較例の全固体二次電池を０．２Ｃの定電流にて電圧２．７Ｖまで充電した後、５Ｃの定電流にて電圧１．５Ｖまで放電した。このときの放電容量を５Ｃ放電容量Ｂとした。５Ｃ放電容量Ｂも基準容量Ａと同様に、１０個の全固体二次電池の放電容量の平均値とした。
　最後に、各実施例及び比較例の全固体二次電池のそれぞれについて、５Ｃ放電容量Ｂと基準容量Ａの放電容量の比（Ｂ／Ａ（％））で表される放電容量維持率を求め、これを電気化学評価の評価基準とした。 Next, the all solid state secondary batteries of the examples and comparative examples were charged to a voltage of 2.7 V at a constant current of 0.2 C, and then discharged to a voltage of 1.5 V at a constant current of 5 C. The discharge capacity at this time was set to 5C discharge capacity B. Similarly to the reference capacity A, the 5C discharge capacity B was also an average value of the discharge capacity of 10 all solid state secondary batteries.
Finally, for each of the all-solid-state secondary batteries of each Example and Comparative Example, a discharge capacity maintenance ratio represented by a ratio (B / A (%)) of the discharge capacity of the 5C discharge capacity B to the reference capacity A is obtained. This was used as an evaluation standard for electrochemical evaluation.
（実施例５の直列全固体二次電池の評価方法）
　各実施例及び比較例の直列全固体二次電池を１０個ずつ準備し、評価を行った。
　実施例５の直列全固体二次電池を０.２Ｃの定電流によって電圧が１３．５Ｖとなるまで充電した後、０．２Ｃの定電流にて電圧７．５Ｖまで放電した。このときの放電容量（０．２Ｃ放電容量）を基準容量Ａとした。基準容量Ａは１０個の直列全固体二次電池の放電容量の平均値とした。 (Evaluation method of serial all solid state secondary battery of Example 5)
Ten serial all solid state secondary batteries of each Example and Comparative Example were prepared and evaluated.
The series all solid state secondary battery of Example 5 was charged with a constant current of 0.2 C until the voltage reached 13.5 V, and then discharged with a constant current of 0.2 C to a voltage of 7.5 V. The discharge capacity (0.2 C discharge capacity) at this time was defined as the reference capacity A. The reference capacity A was the average value of the discharge capacity of 10 serial all solid state secondary batteries.
　次に、実施例５の直列全固体二次電池を０．２Ｃの定電流にて電圧１３．５Ｖまで充電した後、５Ｃの定電流にて電圧７．５Ｖまで放電した。このときの放電容量を５Ｃ放電容量Ｂとした。５Ｃ放電容量Ｂも基準容量Ａと同様に、１０個の直列全固体二次電池の放電容量の平均値とした。
　最後に、実施例５の全固体二次電池のそれぞれについて、５Ｃ放電容量Ｂと基準容量Ａの放電容量の比（Ｂ／Ａ（％））で表される放電容量維持率を求め、これを電気化学評価の評価基準とした。 Next, the series all solid state secondary battery of Example 5 was charged to a voltage of 13.5 V at a constant current of 0.2 C, and then discharged to a voltage of 7.5 V at a constant current of 5 C. The discharge capacity at this time was set to 5C discharge capacity B. Similarly to the reference capacity A, the 5C discharge capacity B was also set to the average value of the discharge capacity of 10 series all solid state secondary batteries.
Finally, for each of the all-solid-state secondary batteries of Example 5, a discharge capacity maintenance ratio represented by a ratio (B / A (%)) of 5C discharge capacity B to reference capacity A is obtained. Evaluation criteria for electrochemical evaluation were used.
　以下の表１に、電気化学評価の評価結果を示す。 Table 1 below shows the evaluation results of the electrochemical evaluation.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、Ｔｂ≦Ｔｓｅ≦ＴａかつＴｂ＜Ｔａの条件を双方満たす実施例１から実施例５の各全固体二次電池は、いずれも十分な放電容量維持率を示す電気化学評価結果が得られた。実施例２の全固体二次電池は、実施例１の全固体二次電池と比較すると放電容量維持率がやや低下しており、負極層と積層体グリーンシートの焼成後に貼り付けた負極集電体との間の界面抵抗が実施例１よりも増加していると推測された。実施例５の全固体二次電池は、連続積層構造であることによりバインダーが分解しにくくなったが、昇温速度を実施例１から実施例４よりも下げているため、電気化学評価は問題ない性能を示したと推測された。
　一方、比較例１の全固体二次電池は、焼成工程において正極集電体と第１の活物質層である正極との間で層間剥離が生じて電極が破壊されたため、電気化学評価を実施できなかった。また、比較例２及び比較例３は、基準容量Ａ及び５Ｃ放電容量Ｂ並びに放電容量維持率が著しく低下した。これは、各層のバインダーが無機粒子の焼結温度まで残存したため焼結が阻害されて、界面抵抗が高かったためであると推測された。 As shown in Table 1, each of the all-solid-state secondary batteries of Examples 1 to 5 satisfying both the conditions of Tb ≦ Tse ≦ Ta and Tb <Ta shows an electrochemical evaluation indicating a sufficient discharge capacity maintenance rate. Results were obtained. The all-solid-state secondary battery of Example 2 has a slightly lower discharge capacity retention rate than the all-solid-state secondary battery of Example 1, and the negative electrode current collector pasted after firing the negative electrode layer and the laminate green sheet It was estimated that the interfacial resistance between the body and the body was higher than that in Example 1. In the all-solid-state secondary battery of Example 5, the binder was less likely to be decomposed due to the continuous laminated structure. However, the rate of temperature increase was lower than in Examples 1 to 4, so that electrochemical evaluation was a problem. It was speculated that it showed no performance.
On the other hand, the all-solid-state secondary battery of Comparative Example 1 was subjected to electrochemical evaluation because delamination occurred between the positive electrode current collector and the positive electrode as the first active material layer in the firing process, and the electrode was destroyed. could not. Further, in Comparative Example 2 and Comparative Example 3, the reference capacity A and 5C discharge capacity B and the discharge capacity retention rate were significantly reduced. This was presumed to be because the binder in each layer remained up to the sintering temperature of the inorganic particles, so that the sintering was inhibited and the interface resistance was high.
　以上のとおり、積層体グリーンシートにおいて、集電体上に設けられた第１電極層グリーンシートに含まれる第１バインダー、第１電極層グリーンシート上に設けられた固体電解質層グリーンシートに含まれる第２バインダー、固体電解質層グリーンシート上に設けられた第２電極層グリーンシートに含まれる第３バインダーの熱重量減少ピーク温度を調整することにより、全固体二次電池製造時における電極破壊や、基準容量Ａ及び５Ｃ放電容量Ｂ並びに放電容量維持率の著しい低下を招くことなく電池性能が良好な全固体二次電池を得ることができた。 As described above, in the laminate green sheet, the first binder included in the first electrode layer green sheet provided on the current collector, and the solid electrolyte layer green sheet provided on the first electrode layer green sheet. By adjusting the second binder, the thermogravimetric decrease peak temperature of the third binder contained in the second electrode layer green sheet provided on the solid electrolyte layer green sheet, An all-solid secondary battery with good battery performance could be obtained without causing a significant decrease in the reference capacity A and 5C discharge capacity B and the discharge capacity retention rate.
　また、本実施形態の製造方法で製造される全固体二次電池は、積層体グリーンシートを一括焼成して作製することができるため、全固体二次電池の作製工程が簡易となった。 Moreover, since the all-solid-state secondary battery manufactured by the manufacturing method of the present embodiment can be manufactured by firing the laminated green sheet at once, the manufacturing process of the all-solid-state secondary battery is simplified.
　本発明の範囲は、図示され記載された例示的な実施形態に限定されるものではなく、本発明が目的とするものと均等な効果をもたらす全ての実施形態をも含む。さらに、本発明の範囲は、請求項により画される発明の特徴の組み合わせに限定されるものではなく、全ての開示されたそれぞれの特徴のうち特定の特徴のあらゆる所望する組み合わせによって画されうる。 The scope of the present invention is not limited to the illustrated and described exemplary embodiments, but includes all embodiments that provide the same effects as those intended by the present invention. Further, the scope of the invention is not limited to the combinations of features of the invention defined by the claims, but can be defined by any desired combination of specific features among all the disclosed features.
（参考例）
　上述した本実施形態に係る積層体グリーンシート及び連続積層体グリーンシート、並びにそれらの製造方法及び全固体二次電池の製造方法が有する技術的特徴を備えない積層体グリーンシート及び連続積層体グリーンシート、並びにそれらの製造方法及び全固体二次電池の製造方法について、本実施形態の参考例として、以下、簡単に説明する。 (Reference example)
Laminated green sheet and continuous laminated green sheet according to the present embodiment described above, laminated green sheet and continuous laminated green sheet that do not have the technical characteristics of the production method and the production method of the all-solid-state secondary battery A manufacturing method thereof and a manufacturing method of an all solid state secondary battery will be briefly described below as a reference example of the present embodiment.
　ノート型パーソナルコンピュータ、スマートフォンに代表される携帯電話、デジタルカメラ等の電子機器の高機能化に伴い、これら電子機器の消費電力が増大している。また、これら電子機器の小型化が求められている。このため、電子機器に用いられる二次電池に対してさらなる高エネルギー密度化が求められている。
　また、定置用途である家庭用蓄電池においても高エネルギー密度化が求められている。更に、近年、ハイブリッド車や電気自動車などの車載用途の二次電池の需要拡大に伴い、二次電池の高出力密度化、高エネルギー密度化の両立が求められている。この他にも、二次電池には電解液に有機溶媒が使用されている為、電解液の漏液や熱暴走の促進などのおそれがあり、二次電池の安全性向上も求められている。 As electronic devices such as notebook personal computers, mobile phones typified by smartphones, and digital cameras become more sophisticated, the power consumption of these electronic devices is increasing. In addition, miniaturization of these electronic devices is required. For this reason, the further high energy density is calculated | required with respect to the secondary battery used for an electronic device.
High energy density is also required for household storage batteries that are stationary applications. Further, in recent years, with the expansion of demand for secondary batteries for in-vehicle applications such as hybrid vehicles and electric vehicles, it is required to achieve both higher output density and higher energy density of secondary batteries. In addition to this, since an organic solvent is used for the electrolyte in the secondary battery, there is a risk of leakage of the electrolyte or acceleration of thermal runaway, and there is a demand for improved safety of the secondary battery. .
　そして、これらの要求を満たす二次電池として最も有力であるのが、負極層、電解質層及び正極層の全構成が固体材料から成る全固体リチウムイオン二次電池である。この全固体リチウムイオン二次電池は、高エネルギー密度、高い安全性、長寿命を兼ね備えた電池として、開発が進んでいる。 And, the most promising secondary battery that satisfies these requirements is an all-solid lithium ion secondary battery in which the entire structure of the negative electrode layer, the electrolyte layer, and the positive electrode layer is made of a solid material. This all-solid-state lithium ion secondary battery is being developed as a battery having high energy density, high safety, and long life.
　しかしながら、現在実用化されている全固体リチウムイオン二次電池は、負極層、固体電解質層及び正極層の各層が非常に薄膜な全固体二次電池であり、エネルギー密度は高くない。さらに、正極層、固体電解質層及び負極層を、蒸着法又はスパッタ法により作製している為、減圧雰囲気下で全固体リチウムイオン二次電池を製造する必要があり、大面積化、大量生産には不適である。 However, the all-solid-state lithium ion secondary battery currently in practical use is an all-solid-state secondary battery in which each of the negative electrode layer, the solid electrolyte layer, and the positive electrode layer is very thin, and its energy density is not high. Furthermore, since the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are produced by vapor deposition or sputtering, it is necessary to produce an all-solid lithium ion secondary battery in a reduced-pressure atmosphere. Is unsuitable.
　そこで、特許文献１から特許文献３に開示されているように、正極層、固体電解質層及び負極層の各層グリーンシートを焼成することで、大面積化かつ大量生産を可能にする全固体リチウムイオン二次電池を作製する手法が検討されている。 Therefore, as disclosed in Patent Document 1 to Patent Document 3, all the solid lithium ions that enable large area production and mass production by firing the green sheets of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer. Techniques for producing secondary batteries are being studied.
　特許文献１には、正極層グリーンシート、負極層グリーンシートを焼成して正極層焼成体、負極層焼成体を作製した後、イオン伝導性無機物質層グリーンシートを介して正極層焼成体、負極層焼成体を挟み込み、再焼成して積層焼成体を形成することが記載されている。特許文献１では、この積層焼成体を２枚の集電板で挟み込んで作製した全固体二次電池が開示されている。 In Patent Document 1, a positive electrode layer green sheet and a negative electrode layer green sheet are fired to produce a positive electrode layer fired body and a negative electrode layer fired body, and then a positive electrode layer fired body and a negative electrode through an ion conductive inorganic material layer green sheet. It describes that a layered fired body is sandwiched and refired to form a laminated fired body. Patent Document 1 discloses an all-solid secondary battery produced by sandwiching the laminated fired body between two current collector plates.
　特許文献２には、正極層グリーンシート、イオン伝導性無機物質層グリーンシート及び負極層グリーンシートを順に貼り合わせて積層体を形成して一括焼成して積層焼成体を形成した後、積層焼成体を２枚の集電板で挟み込んで作製した全固体二次電池が開示されている。 In Patent Document 2, a positive electrode layer green sheet, an ion conductive inorganic material layer green sheet, and a negative electrode layer green sheet are laminated in order to form a laminated body and then collectively fired to form a laminated fired body. Discloses an all-solid-state secondary battery produced by sandwiching a battery between two current collector plates.
　特許文献３には、イオン伝導性無機物質層グリーンシートの両面に正極層グリーンシート及び負極層グリーンシートをそれぞれ印刷形成し、更にその上層に各金属箔集電体ペーストを印刷形成した積層体グリーンシートを一括焼成して作製した全固体二次電池が開示されている。 Patent Document 3 discloses a laminate green in which a positive electrode layer green sheet and a negative electrode layer green sheet are printed on both surfaces of an ion conductive inorganic material layer green sheet, and each metal foil current collector paste is printed on the upper layer. An all-solid secondary battery produced by batch firing sheets is disclosed.
１　全固体二次電池
１ａ　積層体
１０，１０ａ，１０ｂ，１０ｃ，１０ｄ，１０ｅ　積層体グリーンシート
１１　正極集電体
１２　正極層
１２ａ　正極層グリーンシート
１３　固体電解質層
１３ａ　固体電解質層グリーンシート
１４　負極層
１４ａ　負極層グリーンシート
１５　負極集電体
２０　電極積層体
２１　直列全固体二次電池
２１ａ　積層体
３０　連続積層体グリーンシート DESCRIPTION OF SYMBOLS 1 All-solid-state secondary battery 1a Laminated body 10,10a, 10b, 10c, 10d, 10e Laminated body green sheet 11 Positive electrode collector 12 Positive electrode layer 12a Positive electrode layer green sheet 13 Solid electrolyte layer 13a Solid electrolyte layer green sheet 14 Negative electrode layer 14a Negative electrode layer green sheet 15 Negative electrode current collector 20 Electrode laminate 21 Series all solid state secondary battery 21a Laminate 30 Continuous laminate green sheet

Claims (8)

  1. 　金属箔集電体と、
    　前記金属箔集電体上に設けられ、第１バインダーを含む第１電極層グリーンシートと、
    　前記第１電極層グリーンシート上に設けられ、第２バインダーを含む固体電解質層グリーンシートと、
    　前記固体電解質層グリーンシート上に設けられ、第３バインダーを含む第２電極層グリーンシートと、
    を備え、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    積層体グリーンシート。     A metal foil current collector,
    A first electrode layer green sheet provided on the metal foil current collector and containing a first binder;
    A solid electrolyte layer green sheet provided on the first electrode layer green sheet and containing a second binder;
    A second electrode layer green sheet provided on the solid electrolyte layer green sheet and containing a third binder;
    With
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    Laminate green whose easiness of decomposing the third binder is greater than the easiness of decomposing of the first binder and equal to the easiness of decomposing of the second binder or greater than the easiness of decomposing of the second binder. Sheet.
  2. 　前記第１バインダーの熱重量減少ピーク温度Ｔａ、前記第２バインダーの熱重量減少ピーク温度Ｔｓｅ及び前記第３バインダーの熱重量減少ピーク温度Ｔｂは、以下の式（１）及び式（２）を満たす
    請求項１に記載の積層体グリーンシート。
    　　　Ｔｂ≦Ｔｓｅ≦Ｔａ　　　　　　　　　・・・（１）
    　　　Ｔｂ＜Ｔａ　　　　　　　　　　　　　・・・（２）     The thermogravimetric decrease peak temperature Ta of the first binder, the thermogravimetric decrease peak temperature Tse of the second binder, and the thermogravimetric decrease peak temperature Tb of the third binder satisfy the following formulas (1) and (2). The laminate green sheet according to claim 1.
    Tb ≦ Tse ≦ Ta (1)
    Tb <Ta (2)
  3. 　金属箔集電体と、
    　前記金属箔集電体上に設けられ、第１バインダーを含む第１電極層グリーンシートと、
    　前記第１電極層グリーンシート上に設けられ、第２バインダーを含む固体電解質層グリーンシートと、
    　前記固体電解質層グリーンシート上に設けられ、第３バインダーを含む第２電極層グリーンシートと、
    を備える積層体グリーンシートが連続的に積層され、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    連続積層体グリーンシート。     A metal foil current collector,
    A first electrode layer green sheet provided on the metal foil current collector and containing a first binder;
    A solid electrolyte layer green sheet provided on the first electrode layer green sheet and containing a second binder;
    A second electrode layer green sheet provided on the solid electrolyte layer green sheet and containing a third binder;
    Laminated green sheets comprising are continuously laminated,
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    The ease of decomposing the third binder is greater than the easiness of decomposing the first binder and is equal to the easiness of decomposing the second binder or greater than the easiness of decomposing the second binder. Green sheet.
  4. 　前記第１バインダーの熱重量減少ピーク温度Ｔａ、前記第２バインダーの熱重量減少ピーク温度Ｔｓｅ及び前記第３バインダーの熱重量減少ピーク温度Ｔｂは、以下の式（１）及び式（２）を満たす
    請求項３に記載の連続積層体グリーンシート。
    　　　Ｔｂ≦Ｔｓｅ≦Ｔａ　　　　　　　　　・・・（１）
    　　　Ｔｂ＜Ｔａ　　　　　　　　　　　　　・・・（２）     The thermogravimetric decrease peak temperature Ta of the first binder, the thermogravimetric decrease peak temperature Tse of the second binder, and the thermogravimetric decrease peak temperature Tb of the third binder satisfy the following formulas (1) and (2). The continuous laminated body green sheet of Claim 3.
    Tb ≦ Tse ≦ Ta (1)
    Tb <Ta (2)
  5. 　金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して、第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程と、
    　前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して、固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程と、
    　前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して、第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程と、
    を備え、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    積層体グリーンシートの製造方法。     A first electrode layer green sheet forming step of forming a first electrode layer green sheet by applying or printing a first electrode slurry containing a first binder on a metal foil current collector and then drying;
    A solid electrolyte layer green sheet forming step of forming a solid electrolyte layer green sheet by applying or printing a slurry for a solid electrolyte containing a second binder on the first electrode layer green sheet and then drying,
    A second electrode layer green sheet forming step of forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying;
    With
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    Laminate green whose easiness of decomposing the third binder is greater than the easiness of decomposing of the first binder and equal to the easiness of decomposing of the second binder or greater than the easiness of decomposing of the second binder. Sheet manufacturing method.
  6. 　金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して、第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程と、
    　前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して、固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程と、
    　前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して、第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程と、
    　前記金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートが順に積層された積層体グリーンシートを、複数連続的に積層するグリーンシート積層工程と、
    を備え、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    連続積層体グリーンシートの製造方法。     A first electrode layer green sheet forming step of forming a first electrode layer green sheet by applying or printing a first electrode slurry containing a first binder on a metal foil current collector and then drying;
    A solid electrolyte layer green sheet forming step of forming a solid electrolyte layer green sheet by applying or printing a slurry for a solid electrolyte containing a second binder on the first electrode layer green sheet and then drying,
    A second electrode layer green sheet forming step of forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder on the solid electrolyte layer green sheet and then drying;
    A green sheet laminating step of continuously laminating a plurality of laminate green sheets in which the metal foil current collector, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second electrode layer green sheet are sequentially laminated. When,
    With
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    The ease of decomposing the third binder is greater than the easiness of decomposing the first binder and is equal to the easiness of decomposing the second binder or greater than the easiness of decomposing the second binder. Green sheet manufacturing method.
  7. 　第１金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して、第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して、固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程、及び前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して、第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程を含み、前記第１金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートをこの順に備えた積層体グリーンシートを生成する積層体グリーンシート形成工程と、
    　前記積層体グリーンシートの表面に露出する前記第２電極層グリーンシート上に、第２金属箔集電体を貼り合わせる第２金属箔集電体貼り合わせ工程と、
    　前記積層体グリーンシート及び前記積層体グリーンシートに貼り合わされた前記第２金属箔集電体を含む積層体を一括して焼成する焼成工程と、
    を備え、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    全固体二次電池の製造方法。     A first electrode layer green sheet forming step of forming a first electrode layer green sheet by applying or printing a first electrode slurry containing a first binder on the first metal foil current collector and then drying the slurry; A solid electrolyte layer green sheet forming step for forming a solid electrolyte layer green sheet by applying or printing a slurry for solid electrolyte containing a second binder on one electrode layer green sheet and then drying, and the solid electrolyte layer green sheet A second electrode layer green sheet forming step of forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder and then drying the slurry; Body, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second electrode layer green sheet in this order. A laminate green sheet formation process of generating over bets,
    A second metal foil current collector bonding step of bonding a second metal foil current collector onto the second electrode layer green sheet exposed on the surface of the laminate green sheet;
    A firing step of firing together the laminate including the laminate green sheet and the second metal foil current collector bonded to the laminate green sheet;
    With
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    The ease of decomposition of the third binder is greater than the ease of decomposition of the first binder, and is equal to the ease of decomposition of the second binder or greater than the ease of decomposition of the second binder. A method for manufacturing a secondary battery.
  8. 　第１金属箔集電体上に、第１バインダーを含む第１電極用スラリーを塗布又は印刷したのち乾燥して、第１電極層グリーンシートを形成する第１電極層グリーンシート形成工程、前記第１電極層グリーンシート上に、第２バインダーを含む固体電解質用スラリーを塗布又は印刷したのち乾燥して、固体電解質層グリーンシートを形成する固体電解質層グリーンシート形成工程、及び前記固体電解質層グリーンシート上に、第３バインダーを含む第２電極用スラリーを塗布又は印刷したのち乾燥して、第２電極層グリーンシートを形成する第２電極層グリーンシート形成工程を含み、前記第１金属箔集電体、前記第１電極層グリーンシート、前記固体電解質層グリーンシート及び前記第２電極層グリーンシートをこの順に備えた積層体グリーンシートを生成する積層体グリーンシート形成工程と、
    　前記積層体グリーンシートを複数積層して連続積層体グリーンシートを生成する連続積層体グリーンシート形成工程と、
    　前記連続積層体グリーンシートの表面に露出する前記第２電極層グリーンシート上に、第２金属箔集電体を貼り合わせる第２金属箔集電体貼り合わせ工程と、
    　前記連続積層体グリーンシート及び前記連続積層体グリーンシートに貼り合わされた前記第２金属箔集電体を含む積層体を一括して焼成する焼成工程と、
    を備え、
    　前記第２バインダーの分解しやすさは、前記第１バインダーの分解しやすさと同等か又は前記第１バインダーの分解しやすさよりも大きく、
    　前記第３バインダーの分解しやすさは、前記第１バインダーの分解しやすさよりも大きく、かつ前記第２バインダーの分解しやすさと同等か又は前記第２バインダーの分解しやすさよりも大きい
    全固体二次電池の製造方法。     A first electrode layer green sheet forming step of forming a first electrode layer green sheet by applying or printing a first electrode slurry containing a first binder on the first metal foil current collector and then drying the slurry; A solid electrolyte layer green sheet forming step for forming a solid electrolyte layer green sheet by applying or printing a slurry for solid electrolyte containing a second binder on one electrode layer green sheet and then drying, and the solid electrolyte layer green sheet A second electrode layer green sheet forming step of forming a second electrode layer green sheet by applying or printing a slurry for a second electrode containing a third binder and then drying the slurry; Body, the first electrode layer green sheet, the solid electrolyte layer green sheet, and the second electrode layer green sheet in this order. A laminate green sheet formation process of generating over bets,
    A continuous laminate green sheet forming step of producing a continuous laminate green sheet by laminating a plurality of laminate green sheets;
    A second metal foil current collector bonding step of bonding a second metal foil current collector onto the second electrode layer green sheet exposed on the surface of the continuous laminate green sheet;
    A firing step of firing the laminate including the continuous laminate green sheet and the second metal foil current collector bonded to the continuous laminate green sheet together;
    With
    The ease of decomposition of the second binder is equal to or greater than the ease of decomposition of the first binder, or greater than the ease of decomposition of the first binder,
    The ease of decomposition of the third binder is greater than the ease of decomposition of the first binder, and is equal to the ease of decomposition of the second binder or greater than the ease of decomposition of the second binder. A method for manufacturing a secondary battery.
PCT/JP2017/006630 2016-02-23 2017-02-22 Laminate green sheet and continuous laminate green sheet, method for manufacturing same, and method for manufacturing all-solid-state secondary battery WO2017146105A1 (en)

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WO2013035525A1 (en) * 2011-09-09 2013-03-14 株式会社 村田製作所 Laminated molded body for all-solid-state battery, all-solid-state battery, and production method therefor
JP2015069843A (en) * 2013-09-30 2015-04-13 Fdk株式会社 All-solid battery, and method for manufacturing all-solid battery

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013035525A1 (en) * 2011-09-09 2013-03-14 株式会社 村田製作所 Laminated molded body for all-solid-state battery, all-solid-state battery, and production method therefor
JP2015069843A (en) * 2013-09-30 2015-04-13 Fdk株式会社 All-solid battery, and method for manufacturing all-solid battery

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