WO2018164051A1 - All-solid-state secondary battery, production method for same, solid electrolyte film for all-solid-state-electrolyte battery, and production method for same - Google Patents

All-solid-state secondary battery, production method for same, solid electrolyte film for all-solid-state-electrolyte battery, and production method for same Download PDF

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WO2018164051A1
WO2018164051A1 PCT/JP2018/008328 JP2018008328W WO2018164051A1 WO 2018164051 A1 WO2018164051 A1 WO 2018164051A1 JP 2018008328 W JP2018008328 W JP 2018008328W WO 2018164051 A1 WO2018164051 A1 WO 2018164051A1
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solid electrolyte
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state secondary
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真二 今井
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富士フイルム株式会社
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    • H—ELECTRICITY
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    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
    • H—ELECTRICITY
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    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/10—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances sulfides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0562—Solid materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
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    • 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
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    • 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 inorganic solid electrolyte material has particles having a large particle diameter and particles having a small particle diameter, and has a particle size distribution satisfying [particle diameter of large particle diameter]> 4 ⁇ [particle diameter of small particle diameter].
  • the inorganic solid electrolyte is an inorganic solid electrolyte, and the solid electrolyte is a solid electrolyte capable of moving ions inside. Since it does not contain organic substances as the main ion conductive material, organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO), etc., organics typified by lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), etc. It is clearly distinguished from the electrolyte salt). In addition, since the inorganic solid electrolyte is solid in a steady state, it is not usually dissociated or released into cations and anions.
  • organic solid electrolytes polymer electrolytes typified by polyethylene oxide (PEO), etc.
  • LiTFSI lithium bis (trifluoromethanesulfonyl) imide
  • transition metal oxides having (MA) layered rock-salt structure LiCoO 2 (lithium cobaltate [LCO]), LiNi 2 O 2 ( lithium nickelate) LiNi 0.85 Co 0.10 Al 0.05 O 2 (lithium nickel cobalt aluminate [NCA]), LiNi 1/3 Co 1/3 Mn 1/3 O 2 (nickel manganese lithium cobaltate [NMC]) and LiNi 0.5 Mn 0.5 O 2 (manganese) Lithium nickelate).
  • the volume average particle diameter of the obtained LPS was measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA), and as a result, it was 8 ⁇ m. Further, in this LPS, the relationship between the particle size of the large particle size and the particle size of the smaller particle size is [particle size of large particle size]> 4 ⁇ [particle size of small particle size] Particles having a relationship satisfying the [diameter].
  • Example 2 and all solid state secondary batteries of Comparative Examples 1 to 3 were obtained in the same manner as the all solid state secondary battery of Example 1, except that the conditions shown in the table below were changed.

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Abstract

Provided are: an all-solid-state secondary battery wherein a solid electrolyte layer has an electrolyte region occupied by an inorganic solid electrolyte material and a filler region closing a gap between the electrolyte region and the inorganic solid electrolyte material, said filler region being formed using a hot melt of an electron-insulating material that is solid at 100°C and thermally melts in a temperate range of 200°C or lower; a solid electrolyte film used in same; and production methods for these. An all-solid-state secondary battery wherein a solid electrolyte layer has an electrolyte region occupied by an inorganic solid electrolyte material and a filler region closing a gap between the electrolyte region and the inorganic solid electrolyte material, said filler region including an electron-insulating material that is solid at 100°C and thermally melts at no more than 200°C, and the ratio between the area FA of the filler region FR contained inside a square region having one side of 5 µm and the outer perimeter length FL of FR fulfilling FL/FA ≥ 0.81; a solid electrolyte film used in same; and production methods for these.

Description

全固体二次電池及びその製造方法、並びに全固体二次電池用固体電解質膜及びその製造方法All solid state secondary battery and method for producing the same, solid electrolyte membrane for all solid state secondary battery and method for producing the same
　本発明は、全固体二次電池及びその製造方法に関する。また本発明は、全固体二次電池用固体電解質膜及びその製造方法に関する。 The present invention relates to an all-solid-state secondary battery and a method for manufacturing the same. The present invention also relates to a solid electrolyte membrane for an all-solid secondary battery and a method for producing the same.
　リチウムイオン二次電池は、負極と、正極と、負極と正極との間に挟まれた電解質とを有し、両極間にリチウムイオンを往復移動させることにより充電と放電を可能とした蓄電池である。リチウムイオン二次電池には従来から、電解質として有機電解液が用いられてきた。しかし有機電解液は液漏れを生じやすく、また、過充電、過放電により電池内部で短絡が生じ発火するおそれもあり、信頼性と安全性のさらなる向上が求められている。
　このような状況下、有機電解液に代えて、不燃性の無機固体電解質を用いた全固体二次電池の開発が進められている。全固体二次電池は負極、電解質及び正極のすべてが固体からなり、有機電解液を用いた電池の課題とされる安全性ないし信頼性を大きく改善することができ、また長寿命化も可能になるとされる。 A lithium ion secondary battery is a storage battery that has a negative electrode, a positive electrode, and an electrolyte sandwiched between the negative electrode and the positive electrode, and enables charging and discharging by reciprocating lithium ions between the two electrodes. . Conventionally, an organic electrolytic solution has been used as an electrolyte in a lithium ion secondary battery. However, organic electrolytes are liable to leak, and overcharge and overdischarge can cause a short circuit inside the battery, resulting in fire, and further improvements in reliability and safety are required.
Under such circumstances, development of an all-solid secondary battery using an incombustible inorganic solid electrolyte instead of the organic electrolyte is being promoted. The all-solid-state secondary battery is composed of a solid anode, electrolyte, and cathode, which can greatly improve safety and reliability, which is a problem for batteries using organic electrolytes, and can also extend the service life. It will be.
　リチウムイオン二次電池は、充電時には正極から負極へと電子が移動し、同時に正極を構成するリチウム酸化物等からリチウムイオンが放出され、このリチウムイオンは電解質を通って負極へと到達して負極に溜め込まれる。こうして負極に溜め込まれたリチウムイオンの一部は電子を取り込み金属リチウムとして析出する現象が生じる。この金属リチウムの析出物が充放電の繰り返しによりデンドライト状に成長してしまうと、やがて正極へと達し、内部短絡が生じて二次電池として機能しなくなってしまう。デンドライトは非常に細く、電解質として固体を用いる全固体二次電池においても、固体電解質層に生じた亀裂ないしピンホール等を通って成長する。したがって、全固体二次電池においてもデンドライトの成長をブロックすることは、電池を長寿命化する上で重要である。
　デンドライトによる内部短絡の問題に対処すべく特許文献１には、固体電解質層中に単体硫黄を過剰に添加し、デンドライトの成長を単体硫黄によりブロックする技術が記載されている。特許文献１記載の技術では、固体電解質粉末に単体硫黄を均一に分散させた混合物を用いて固体電解質層を形成しているため、この固体電解質層は単体硫黄粉末と固体電解質粉末との混合物からなる形態である。 In a lithium ion secondary battery, electrons move from the positive electrode to the negative electrode during charging, and at the same time, lithium ions are released from lithium oxide or the like constituting the positive electrode. Accumulated. In this way, a part of the lithium ions stored in the negative electrode takes in electrons and precipitates as metallic lithium. If this metal lithium deposit grows in a dendrite shape due to repeated charge and discharge, it will eventually reach the positive electrode, causing an internal short circuit, and will not function as a secondary battery. The dendrite is very thin and grows through cracks or pinholes generated in the solid electrolyte layer even in an all-solid secondary battery using a solid as an electrolyte. Therefore, blocking the growth of dendrites in all solid state secondary batteries is important for extending the battery life.
In order to cope with the problem of internal short circuit due to dendrites, Patent Document 1 describes a technique in which elemental sulfur is excessively added to the solid electrolyte layer, and dendrite growth is blocked by elemental sulfur. In the technology described in Patent Document 1, since the solid electrolyte layer is formed using a mixture in which simple sulfur is uniformly dispersed in the solid electrolyte powder, the solid electrolyte layer is formed from a mixture of the simple sulfur powder and the solid electrolyte powder. It is a form.
国際公開第２０１１／０１０５５２号International Publication No. 2011/010552
　電解質として有機電解液を用いたリチウムイオン二次電池は、正極、電解質及び負極からなる層構成の電池シートを軸心に巻きつけて電池シートをロール状（円筒型）の積層状態とし、これにより電池の高出力化が図られている。全固体二次電池においても、高出力化のために電池形状を円筒型にすることも検討されている。しかし、全固体二次電池を円筒型にする場合には、電解質層が固体であるがゆえに電解質層に亀裂、ピンホール等が生じやすい。その結果、デンドライトの成長による内部短絡の問題がより顕在化することになる。上記特許文献１記載の技術は、固体電解質層中に分散させた単体硫黄粉末によりデンドライトの成長をブロックするものであるが、固体電解質層中に単体硫黄粉末を混合するだけでは、固体電解質間の空隙を隙間なく埋めることは難しい。 A lithium ion secondary battery using an organic electrolyte as an electrolyte has a battery sheet having a layer structure composed of a positive electrode, an electrolyte, and a negative electrode wound around an axis to form a battery sheet in a roll (cylindrical) stacked state. The output of the battery is increased. Also in the all-solid-state secondary battery, it is also considered to make the battery shape cylindrical for high output. However, when the all-solid-state secondary battery is made cylindrical, the electrolyte layer is solid, so that the electrolyte layer is likely to be cracked, pinholes, and the like. As a result, the problem of internal short circuit due to the growth of dendrites becomes more obvious. The technique described in Patent Document 1 blocks the growth of dendrites by the simple sulfur powder dispersed in the solid electrolyte layer. It is difficult to fill the gap without gaps.
　本発明は、固体電解質層に生じた亀裂、ピンホール等の空隙が十分に塞がれた、充放電サイクル特性に優れた全固体二次電池及びその製造方法を提供することを課題とする。また本発明は、固体電解質層に生じた亀裂、ピンホール等の空隙が十分に塞がれ、全固体二次電池の固体電解質層として用いることにより、充放電サイクル特性に優れた全固体二次電池を得ることを可能とする固体電解質膜及びその製造方法を提供することを課題とする。 An object of the present invention is to provide an all-solid-state secondary battery excellent in charge / discharge cycle characteristics in which voids such as cracks and pinholes generated in the solid electrolyte layer are sufficiently closed, and a method for manufacturing the same. In addition, the present invention provides an all-solid secondary with excellent charge / discharge cycle characteristics by sufficiently closing voids such as cracks and pinholes generated in the solid electrolyte layer and using it as a solid electrolyte layer of an all-solid secondary battery. It is an object of the present invention to provide a solid electrolyte membrane capable of obtaining a battery and a manufacturing method thereof.
　本発明者は上記課題に鑑み鋭意検討を重ねた結果、１００℃においては固体であり、２００℃以下の温度領域で熱溶融する電子絶縁性の充填材と、固体電解質とを含む混合物を用いて膜を形成し、その後、この膜を加熱して充填材を熱溶融させることにより、毛細管現象を利用して膜中の微小の欠陥（空隙）に充填材を浸透させることができ、膜欠陥が十分に塞がれた形態の固体電解質膜が得られること、この固体電解質膜を全固体二次電池の固体電解質層として用いることにより、負極から析出して成長してくるデンドライトを効果的にブロックすることができ、内部短絡を十分に抑制できることを見い出した。本発明はこれらの知見に基づきさらに検討を重ね、完成されるに至ったものである。 As a result of intensive studies in view of the above problems, the present inventor has used a mixture containing an electronic insulating filler that is solid at 100 ° C. and thermally melted in a temperature range of 200 ° C. or less, and a solid electrolyte. By forming a film and then heating the film to melt the filler, the filler can penetrate into minute defects (voids) in the film by utilizing capillary action. A solid electrolyte membrane in a sufficiently closed form can be obtained, and by using this solid electrolyte membrane as a solid electrolyte layer of an all-solid-state secondary battery, it effectively blocks dendrite that has been deposited and grown from the negative electrode. And found that the internal short circuit can be sufficiently suppressed. The present invention has been further studied based on these findings and has been completed.
　すなわち、上記の課題は以下の手段により解決された。
〔１〕
　固体電解質層が、無機固体電解質材料に占有された電解質領域と、無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
　上記充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料の熱溶融物を用いて形成されたものである、全固体二次電池。
〔２〕
　固体電解質層が、無機固体電解質材料に占有された電解質領域と、無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
　上記充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料を含み、
　１辺が５μｍの正方領域内に収まる充填材領域ＦＲを平面視観察した場合に、ＦＲの面積ＦＡと、ＦＲの外周長さＦＬとの比が、ＦＬ／ＦＡ≧０．８１を満たす、全固体二次電池。
〔３〕
　上記電子絶縁性材料が硫黄及び／又は改質硫黄である、〔１〕又は〔２〕記載の全固体二次電池。
〔４〕
　上記充填材領域が、アルカリ金属を含む化合物及び／又はアルカリ土類金属を含む化合物を含有する、〔１〕～〔３〕のいずれか１つに記載の全固体二次電池。
〔５〕
　上記充填材領域が有機バインダーを含有する、〔１〕～〔４〕のいずれか１つに記載の全固体二次電池。
〔６〕
　上記無機固体電解質材料が硫化物系無機固体電解質及び／又は酸化物系無機固体電解質である、〔１〕～〔５〕のいずれか１つ記載の全固体二次電池。
〔７〕
　上記充填材領域が、上記固体電解質層と正極活物質層との界面には存在しない、〔１〕～〔６〕のいずれか１つに記載の全固体二次電池。
〔８〕
　上記無機固体電解質材料が大粒径の粒子と小粒径の粒子とを有し、[大粒径粒子の粒子径]＞４×[小粒径粒子の粒子径]を満たす粒度分布を有する、〔１〕～〔７〕のいずれか１つに記載の全固体二次電池。
〔９〕
　上記固体電解質層中、無機固体電解質材料の含有量１００体積％に対し、上記電子絶縁性材料の含有量が１５体積％未満である、〔１〕～〔８〕のいずれか１つに記載の全固体二次電池。
〔１０〕
　無機固体電解質材料に占有された電解質領域と、無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
　上記充填材領域は、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料の熱溶融物を用いて形成されたものである、全固体二次電池用固体電解質膜。
〔１１〕
　無機固体電解質材料に占有された電解質領域と、無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
　上記充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料を含み、
　１辺が５μｍの正方領域内に収まる充填材領域ＦＲを平面視観察した場合に、ＦＲの面積ＦＡと、ＦＲの外周長さＦＬとの比が、ＦＬ／ＦＡ≧０．８１を満たす、全固体二次電池用固体電解質膜。
〔１２〕
　上記電子絶縁性材料が硫黄及び／又は改質硫黄である、〔１０〕又は〔１１〕記載の全固体二次電池用固体電解質膜。
〔１３〕
　上記無機固体電解質材料が硫化物系無機固体電解質及び／又は酸化物系無機固体電解質である、〔１０〕～〔１２〕のいずれか１つに記載の全固体二次電池用固体電解質膜。
〔１４〕
　上記無機固体電解質材料が大粒径の粒子と小粒径の粒子とを有し、[大粒径粒子の粒子径]＞４×[小粒径粒子の粒子径]を満たす、〔１０〕～〔１３〕のいずれか１つに記載の全固体二次電池用固体電解質膜。
〔１５〕
　無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した層を加熱し、この層中の硫黄及び／又は改質硫黄を熱溶融させ、次いで冷却して固体電解質層を形成することを含む、〔１〕～〔９〕のいずれか１つに記載の全固体二次電池の製造方法。
〔１６〕
　無機固体電解質材料を用いて形成した層中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却して固体電解質層を形成することを含む、〔１〕～〔９〕のいずれか１つに記載の全固体二次電池の製造方法。
〔１７〕
　無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した膜を加熱し、この膜中の硫黄及び／又は改質硫黄を熱溶融させ、次いで冷却することを含む、〔１０〕～〔１４〕のいずれか１つに記載の全固体二次電池用固体電解質膜の製造方法。
〔１８〕
　無機固体電解質材料を用いて形成した膜中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却することを含む、〔１０〕～〔１４〕のいずれか１つに記載の全固体二次電池用固体電解質膜の製造方法。 That is, the above problem has been solved by the following means.
[1]
The solid electrolyte layer has an electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
The all-solid-state secondary battery, wherein the filler region is formed using a hot melt of an electronic insulating material that is solid at 100 ° C and thermally melts in a temperature region of 200 ° C or lower.
[2]
The solid electrolyte layer has an electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
The filler region includes an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature region of 200 ° C. or less,
When the filler region FR that fits in a square region having one side of 5 μm is observed in plan view, the ratio of the area FA of FR to the outer peripheral length FL of FR satisfies FL / FA ≧ 0.81. Solid secondary battery.
[3]
The all-solid-state secondary battery according to [1] or [2], wherein the electronic insulating material is sulfur and / or modified sulfur.
[4]
The all-solid-state secondary battery according to any one of [1] to [3], wherein the filler region contains a compound containing an alkali metal and / or a compound containing an alkaline earth metal.
[5]
The all-solid-state secondary battery according to any one of [1] to [4], wherein the filler region contains an organic binder.
[6]
The all-solid-state secondary battery according to any one of [1] to [5], wherein the inorganic solid electrolyte material is a sulfide-based inorganic solid electrolyte and / or an oxide-based inorganic solid electrolyte.
[7]
The all-solid-state secondary battery according to any one of [1] to [6], wherein the filler region does not exist at an interface between the solid electrolyte layer and the positive electrode active material layer.
[8]
The inorganic solid electrolyte material has particles having a large particle diameter and particles having a small particle diameter, and has a particle size distribution satisfying [particle diameter of large particle diameter]> 4 × [particle diameter of small particle diameter]. The all solid state secondary battery according to any one of [1] to [7].
[9]
The content of the electronic insulating material is less than 15% by volume with respect to 100% by volume of the inorganic solid electrolyte material in the solid electrolyte layer, according to any one of [1] to [8] All-solid secondary battery.
[10]
An electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
The said filler area | region is a solid electrolyte membrane for all-solid-state secondary batteries formed using the hot melt of the electronic insulating material which is a solid at 100 degreeC, and heat-melts in the temperature range below 200 degreeC.
[11]
An electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
The filler region includes an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature region of 200 ° C. or less,
When the filler region FR that fits in a square region having one side of 5 μm is observed in plan view, the ratio of the area FA of FR to the outer peripheral length FL of FR satisfies FL / FA ≧ 0.81. A solid electrolyte membrane for a solid secondary battery.
[12]
The solid electrolyte membrane for an all-solid-state secondary battery according to [10] or [11], wherein the electronic insulating material is sulfur and / or modified sulfur.
[13]
The solid electrolyte membrane for an all-solid-state secondary battery according to any one of [10] to [12], wherein the inorganic solid electrolyte material is a sulfide-based inorganic solid electrolyte and / or an oxide-based inorganic solid electrolyte.
[14]
The inorganic solid electrolyte material has particles having a large particle diameter and particles having a small particle diameter, and satisfies [particle diameter of large particle diameter]> 4 × [particle diameter of small particle diameter]. [13] The solid electrolyte membrane for an all-solid-state secondary battery according to any one of [13].
[15]
A layer formed using an inorganic solid electrolyte composition containing an inorganic solid electrolyte material and sulfur and / or modified sulfur is heated, and the sulfur and / or modified sulfur in the layer is heated and then cooled. The method for producing an all-solid-state secondary battery according to any one of [1] to [9], comprising forming a solid electrolyte layer.
[16]
[1] to [9], comprising impregnating a layer formed using an inorganic solid electrolyte material with sulfur in a molten state and / or modified sulfur and then cooling to form a solid electrolyte layer. The manufacturing method of the all-solid-state secondary battery as described in any one of these.
[17]
The film formed using the inorganic solid electrolyte composition containing the inorganic solid electrolyte material and sulfur and / or modified sulfur is heated, and the sulfur and / or modified sulfur in the film is heated and then cooled. The method for producing a solid electrolyte membrane for an all-solid-state secondary battery according to any one of [10] to [14].
[18]
The film formed using the inorganic solid electrolyte material is impregnated with sulfur in a hot melt state and / or modified sulfur, and then cooled, and then cooled, according to any one of [10] to [14] The manufacturing method of the solid electrolyte membrane for all-solid-state secondary batteries.
　本明細書において、「～」を用いて表される数値範囲は、「～」の前後に記載される数値を下限値及び上限値として含む範囲を意味する。 In this specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
　本発明の全固体二次電池は、充電時に負極から成長するデンドライトを効果的にブロックすることができ、内部短絡を十分に抑制することができる。また本発明の全固体二次電池用固体電解質膜は、全固体二次電池の固体電解質層として用いることにより、全固体二次電池の充電時に負極から成長するデンドライトを効果的にブロックすることができ、電池の内部短絡を十分に抑制することを可能とする。
　また本発明の全固体二次電池の製造方法によれば、充電時に負極から成長するデンドライトを効果的にブロックすることができ、内部短絡を十分に抑制することができる全固体二次電池を得ることができる。また本発明の全固体二次電池用固体電解質膜の製造方法によれば、全固体二次電池の固体電解質層として用いることにより全固体二次電池の充電時に負極から成長するデンドライトを効果的にブロックすることができ、電池の内部短絡を十分に抑制することを可能とする全固体二次電池用固体電解質膜を得ることができる。 The all-solid-state secondary battery of the present invention can effectively block dendrites that grow from the negative electrode during charging, and can sufficiently suppress internal short circuits. Moreover, the solid electrolyte membrane for an all-solid-state secondary battery of the present invention can effectively block dendrite that grows from the negative electrode during charging of the all-solid-state secondary battery by using it as a solid electrolyte layer of the all-solid-state secondary battery. The internal short circuit of the battery can be sufficiently suppressed.
Moreover, according to the manufacturing method of the all-solid-state secondary battery of this invention, the dendrite which grows from a negative electrode at the time of charge can be blocked effectively, and the all-solid-state secondary battery which can fully suppress an internal short circuit is obtained. be able to. Further, according to the method for producing a solid electrolyte membrane for an all-solid-state secondary battery of the present invention, the dendrite that grows from the negative electrode during the charging of the all-solid-state secondary battery can be effectively obtained by using the solid electrolyte membrane of the all-solid-state secondary battery. A solid electrolyte membrane for an all-solid-state secondary battery that can be blocked and sufficiently suppresses an internal short circuit of the battery can be obtained.
本発明の好ましい実施形態に係る全固体二次電池の基本構造を模式化して示す縦断面図である。It is a longitudinal cross-sectional view which shows typically the basic structure of the all-solid-state secondary battery which concerns on preferable embodiment of this invention. 本発明の好ましい実施形態に係る円筒型全固体二次電池を模式化して示す縦断面図である。1 is a longitudinal sectional view schematically showing a cylindrical all solid state secondary battery according to a preferred embodiment of the present invention.
　本発明の全固体二次電池は、固体電解質層中の無機固体電解質同士の間の空隙が特定の電子絶縁性材料により十分に塞がれており、固体電解質層の厚み方向に向けたデンドライトの成長を効果的にブロックすることができる。
　本発明の好ましい実施形態について説明する。 In the all-solid-state secondary battery of the present invention, the voids between the inorganic solid electrolytes in the solid electrolyte layer are sufficiently closed by a specific electronic insulating material, and the dendrite oriented in the thickness direction of the solid electrolyte layer Growth can be effectively blocked.
A preferred embodiment of the present invention will be described.
［全固体二次電池］
　図１は、本発明の全固体二次電池の一実施形態について、電池を構成する各層の積層状態を模式化して示す断面図である。本実施形態の全固体二次電池１０は、負極側からみて、負極集電体１、負極活物質層２、固体電解質層３、正極活物質層４、正極集電体５を、この順に積層してなる構造を有しており、隣接する層同士は直に接触している。このような構造を採用することで、充電時には、負極側に電子（ｅ－）が供給され、同時に正極活物質を構成するアルカリ金属又はアルカリ土類金属がイオン化して固体電解質層３を通過（伝導）して移動し、負極に蓄積される。例えばリチウムイオン二次電池であれば、負極にリチウムイオン（Ｌｉ＋）が蓄積されることになる。
　一方、放電時には、負極に蓄積された上記のアルカリ金属イオンないしアルカリ土類金属イオンが正極側に戻され、作動部位６に電子を供給することができる。図示した全固体二次電池の例では、作動部位６に電球を採用しており、放電によりこれが点灯するようにされている。 [All-solid secondary battery]
FIG. 1 is a cross-sectional view schematically showing a laminated state of each layer constituting a battery in an embodiment of an all solid state secondary battery of the present invention. The all-solid-state secondary battery 10 according to this embodiment includes a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5 stacked in this order as viewed from the negative electrode side. The adjacent layers are in direct contact with each other. By adopting such a structure, at the time of charging, electrons (e − ) are supplied to the negative electrode side, and at the same time, alkali metal or alkaline earth metal constituting the positive electrode active material is ionized and passes through the solid electrolyte layer 3 ( Conductivity) and move to accumulate in the negative electrode. For example, in the case of a lithium ion secondary battery, lithium ions (Li + ) are accumulated in the negative electrode.
On the other hand, at the time of discharge, the alkali metal ions or alkaline earth metal ions accumulated in the negative electrode are returned to the positive electrode side, and electrons can be supplied to the working part 6. In the example of the all-solid secondary battery shown in the figure, a light bulb is adopted as the operation part 6 and it is lit by discharge.
　また、本発明の全固体二次電池は、負極活物質層２を有さずに、固体電解質層３と負極集電体１とが直に接する形態とすることも好ましい。この形態の全固体二次電池では、充電時に負極に蓄積したアルカリ金属イオンないしアルカリ土類金属イオンの一部が電子と結合し、金属として負極集電体表面に析出する現象を利用する。すなわち、この形態の全固体二次電池は、負極表面に析出した金属を負極活物質層として機能させるものである。例えば金属リチウムは、負極活物質として汎用されている黒鉛に比べて１０倍以上の理論容量を有するとされている。したがって、負極に金属リチウムを析出させてこの析出した金属リチウムに固体電解質層を押しつけた形態とすることにより、集電体表面に金属リチウムの層を形成することができ、高エネルギー密度の二次電池を実現することが可能になるとされる。
　また、負極活物質層を取り除いた形態の全固体二次電池は、電池の厚さが薄くなるために、電池をロール状に巻いた形態とする場合には、固体電解質層の亀裂等の発生をより抑えることが可能になる利点もある。
　なお、本明細書において負極活物質層を有しない形態の全固体二次電池とは、あくまで電池製造における層形成工程において負極活物質層を形成しないことを意味し、上記の通り、充電により固体電解質層と負極集電体との間に負極活物質層が形成されるものである。 Moreover, it is also preferable that the all-solid-state secondary battery of the present invention does not have the negative electrode active material layer 2 and the solid electrolyte layer 3 and the negative electrode current collector 1 are in direct contact with each other. In this form of the all-solid-state secondary battery, a phenomenon is used in which part of alkali metal ions or alkaline earth metal ions accumulated in the negative electrode during charging is combined with electrons and deposited as a metal on the surface of the negative electrode current collector. That is, the all solid state secondary battery of this embodiment is one in which the metal deposited on the negative electrode surface functions as a negative electrode active material layer. For example, metallic lithium is said to have a theoretical capacity 10 times or more that of graphite, which is widely used as a negative electrode active material. Therefore, by depositing metallic lithium on the negative electrode and pressing the solid electrolyte layer against the deposited metallic lithium, a layer of metallic lithium can be formed on the current collector surface, and a high energy density secondary layer can be formed. It is said that a battery can be realized.
In addition, the all-solid-state secondary battery in which the negative electrode active material layer is removed has a thin battery, so that when the battery is rolled up, cracks in the solid electrolyte layer occur. There is also an advantage that it is possible to further suppress.
In the present specification, the all-solid-state secondary battery having no negative electrode active material layer means that the negative electrode active material layer is not formed in the layer formation step in battery manufacture, and as described above, the solid state is obtained by charging. A negative electrode active material layer is formed between the electrolyte layer and the negative electrode current collector.
　図２に示す円筒型全固体二次電池は、図１の層構成を円筒型の形態で実現したものである。この円筒型全固体二次電池は、図１の層構成を基本単位とする発電要素が軸心２２の周りに積層状に形成されている。すなわち、負極集電体２１ｄ、負極活物質層２１ｅ、固体電解質層２１ａ、正極活物質層２１ｃ及び正極集電体２１ｂがこの順に積層された発電要素が複層化された形態を採る。この円筒型全固体二次電池において、隣接する２つの発電要素は集電体１つを共有する形態となる。すなわち、図２に示すように一の集電体の両面に負極活物質層が設けられ、また別の集電体の両面に正極活物質層が設けられた形態となる。また、円筒型全固体二次電池は、必要により電池カバー２３を備えていてもよい。
　図２に示すような積層構造とすることにより、電池を高出力化することが可能となる。 The cylindrical all solid state secondary battery shown in FIG. 2 is obtained by realizing the layer configuration of FIG. 1 in a cylindrical form. In this cylindrical all solid-state secondary battery, a power generation element having the layer configuration of FIG. 1 as a basic unit is formed around the shaft 22 in a laminated form. That is, a power generation element in which the negative electrode current collector 21d, the negative electrode active material layer 21e, the solid electrolyte layer 21a, the positive electrode active material layer 21c, and the positive electrode current collector 21b are stacked in this order is used. In this cylindrical all solid state secondary battery, two adjacent power generation elements share one current collector. That is, as shown in FIG. 2, a negative electrode active material layer is provided on both surfaces of one current collector, and a positive electrode active material layer is provided on both surfaces of another current collector. The cylindrical all solid secondary battery may include a battery cover 23 as necessary.
By adopting the laminated structure as shown in FIG. 2, it becomes possible to increase the output of the battery.
　本発明の全固体二次電池において、正極活物質層、固体電解質層、負極活物質層の厚さは特に限定されない。一般的な電池の寸法を考慮すると、上記各層の厚さは１０～１０００μｍが好ましく、２０μｍ以上５００μｍ未満がより好ましい。 In the all solid state secondary battery of the present invention, the thickness of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is not particularly limited. Considering general battery dimensions, the thickness of each layer is preferably 10 to 1000 μm, more preferably 20 μm or more and less than 500 μm.
　本明細書において、正極活物質層と負極活物質層とを合わせて電極層と称することがある。正極活物質層には正極活物質が含有され、負極活物質層には負極活物質が含有される。正極活物質及び負極活物質のいずれかを示すのに、あるいは両方を合わせて示すのに、単に活物質または電極活物質と称することがある。固体電解質層は通常は正極活物質及び／又は負極活物質を含まない。固体電解質層を構成する無機固体電解質、あるいは固体電解質層を構成する無機固体電解質と活物質との組み合わせを無機固体電解質材料という。　 In this specification, the positive electrode active material layer and the negative electrode active material layer may be collectively referred to as an electrode layer. The positive electrode active material layer contains a positive electrode active material, and the negative electrode active material layer contains a negative electrode active material. In order to indicate either the positive electrode active material or the negative electrode active material, or to indicate both, the active material or the electrode active material may be simply referred to. The solid electrolyte layer usually does not contain a positive electrode active material and / or a negative electrode active material. An inorganic solid electrolyte constituting the solid electrolyte layer or a combination of an inorganic solid electrolyte constituting the solid electrolyte layer and an active material is referred to as an inorganic solid electrolyte material. *
＜固体電解質層＞
　本発明の全固体二次電池は、固体電解質層が無機固体電解質材料に占有された電解質領域と、この無機固体電解質材料間の空隙を塞ぐ充填材領域とを有する。この充填材領域は、デンドライトが貫通可能な固体電解質層中の亀裂ないしピンホール等を塞いでデンドライトの成長をブロックするものである。本発明において「無機固体電解質材料間の空隙を塞ぐ充填材領域を有する」とは、固体電解質層中に存在する無機固体電解質材料間の空隙のうち少なくとも一部が特定の充填材により塞がれ、この充填材により埋められた充填材領域がデンドライトの成長をブロック可能な状態にあることを意味する。 <Solid electrolyte layer>
The all-solid-state secondary battery of the present invention has an electrolyte region in which the solid electrolyte layer is occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material. This filler region blocks dendrite growth by closing cracks or pinholes in the solid electrolyte layer through which the dendrite can penetrate. In the present invention, “having a filler region that closes the gap between the inorganic solid electrolyte materials” means that at least a part of the gap between the inorganic solid electrolyte materials present in the solid electrolyte layer is blocked by a specific filler. This means that the filler region filled with the filler is in a state where dendrite growth can be blocked.
（充填材領域）
　本発明において充填材領域は、単に粒子状の充填材が存在しているのではなく、無機固体電解質材料間の形状に沿って、事実上隙間なく、充填材である電子絶縁性材料が存在している。このような電子絶縁性材料の充填を実現するために、上記電子絶縁性材料としては、１００℃において固体（すなわち融点が１００℃越え）である一方、２００℃以下の温度領域において熱溶融する物性のものを用いる。「２００℃以下の温度領域で熱溶融する」とは、１気圧下において、２００℃以下の温度領域で熱溶融することを意味する。このような電子絶縁性材料を用いることにより、無機固体電解質粉末と電子絶縁性材料とを含む混合物を用いて層を形成した後、電子絶縁性材料が溶融する温度まで容易に加熱することができ、この加熱により、溶融した充填材を毛細管現象によって無機固体電解質材料間の空隙へと移動させることができる。その後冷却して充填材を固化させることにより、無機固体電解質材料間の形状に沿って事実上隙間なく、充填材を埋め込んだ状態を作り出すことができる。
　すなわち、本発明の全固体二次電池において、固体電解質層の充填材領域は、１００℃において固体状でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料の熱溶融物を用いて形成されたもの（すなわち熱溶融凝固物で形成されたもの）である。
　ここで「電子絶縁性」とは、電子を通過させない性質をいう。本発明において「電子絶縁性材料」という場合、測定温度２５℃において導電率が１０－９Ｓ／ｃｍ以下の材料であることが好ましい。 (Filler area)
In the present invention, the filler region is not simply the presence of particulate filler, but is substantially free of gaps along the shape between the inorganic solid electrolyte materials, and there is an electronic insulating material that is the filler. ing. In order to realize the filling of such an electronic insulating material, the electronic insulating material is a solid at 100 ° C. (that is, a melting point exceeding 100 ° C.), while being physically melted in a temperature range of 200 ° C. or lower. Use one. “Heat-melting in a temperature range of 200 ° C. or lower” means to heat-melt in a temperature range of 200 ° C. or lower under 1 atm. By using such an electronic insulating material, after forming a layer using a mixture containing an inorganic solid electrolyte powder and an electronic insulating material, it can be easily heated to a temperature at which the electronic insulating material melts. By this heating, the molten filler can be moved to the gap between the inorganic solid electrolyte materials by capillary action. By subsequently cooling and solidifying the filler, it is possible to create a state in which the filler is embedded with virtually no gap along the shape between the inorganic solid electrolyte materials.
That is, in the all-solid-state secondary battery of the present invention, the filler region of the solid electrolyte layer is formed using a hot melt of an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature range of 200 ° C. or less. (I.e., formed of a hot melt solidified product).
Here, “electron insulating property” refers to a property that does not allow electrons to pass. In the present invention, the “electronic insulating material” is preferably a material having a conductivity of 10 −9 S / cm or less at a measurement temperature of 25 ° C.
　本発明において、充填材領域は電子絶縁性材料の他に、デンドライトの成長をブロック可能な他の材料を含んでもよい。すなわち、本発明において「電子絶縁性材料の熱溶融物を用いて形成された」とは、電子絶縁性材料のみを用いて形成された形態の他、電子絶縁性材料と、電子絶縁性材料以外の他の材料とを組合せて用いて形成された形態を含む意味である。他の材料として、例えば酸化アルミニウム、酸化ケイ素、窒化ホウ素、酸化セリウム、ダイヤモンド、ゼオライト等を挙げることができる。他の材料は通常は微粒子であり、その体積平均粒子径は１μｍ以下が好ましく、７００ｎｍ以下がより好ましい。これらの材料を充填材領域に存在させることにより、熱溶融物が毛細管現象によって固体電解質間の隙間に染み込みやすくなり、デンドライトのブロック作用をより高めることができる。
　充填材領域が電子絶縁性材料に加えて他の材料を含む場合、固体電解質層中において、無機固体電解質材料の含有量１００質量部に対し、他の材料の含有量を１５質量部以下とすることが好ましく、１０質量部以下とすることがより好ましい。 In the present invention, the filler region may include other materials that can block dendrite growth in addition to the electronic insulating material. That is, in the present invention, “formed using a hot melt of an electronic insulating material” means that the electronic insulating material is not only an electronic insulating material and an electronic insulating material other than a form formed using only an electronic insulating material. It is meant to include forms formed using other materials in combination. Examples of other materials include aluminum oxide, silicon oxide, boron nitride, cerium oxide, diamond, and zeolite. The other materials are usually fine particles, and the volume average particle diameter is preferably 1 μm or less, more preferably 700 nm or less. The presence of these materials in the filler region makes it easier for the hot melt to penetrate into the gaps between the solid electrolytes due to the capillary phenomenon, thereby further enhancing the dendrite blocking action.
When the filler region includes other materials in addition to the electronic insulating material, the content of the other material is set to 15 parts by mass or less with respect to 100 parts by mass of the inorganic solid electrolyte material in the solid electrolyte layer. It is preferably 10 parts by mass or less.
　上記のような、無機固体電解質材料間の形状に沿って事実上隙間なく、電子絶縁性材料を含む充填材が埋め込まれた状態は、充填材領域のうち一辺が５μｍの正方領域内に収まる充填材領域ＦＲ（この充填材領域ＦＲの外周（電解質領域との境界）のすべてが５μｍの正方領域内に収まることを意味する）を、固体電解質層の厚み方向に向けて平面視観察（固体電解質層の厚み方向に対して垂直な面を観察）した場合に、ＦＲの面積ＦＡ（μｍ２）と、ＦＲの外周長さＦＬ（μｍ）との比が、ＦＬ／ＦＡ≧０．８１を満たすことが好ましい。
　この平面視観察では、固体電解質層を、走査型電子顕微鏡－エネルギー分散型Ｘ線分光法（ＳＥＭ－ＥＤＸ）を用いて倍率５０００倍で観察して、１辺が５μｍの正方領域内に収まる充填材領域ＦＲを無作為に１０個選抜する。これら１０個の各充填材領域ＦＲにおけるＦＬ／ＦＡを決定し、決定した１０個のＦＬ／ＦＡの平均が０．８１以上である場合に、ＦＬ／ＦＡ≧０．８１を満たすものとする。なお、１つの、１辺が５μｍの正方領域内において、測定する充填材領域の数は１つとする。ＦＬ／ＦＡ≧０．８１を満たすことは、充填材領域が単なる粒子（球状）ではなく、充填材領域の外周が無機固体電解質材料間の形状に追従していることを示す指標となる。
　ＦＬ／ＦＡは１．０以上が好ましく、１．５以上がより好ましく、２．０以上がさらに好ましい。また、ＦＬ／ＦＡは通常は１００以下であり、５０以下であってもよく、２０以下であってもよく、１０以下であってもよい。 As described above, the state in which the filler including the electronic insulating material is embedded substantially without any gap along the shape between the inorganic solid electrolyte materials is filled in a square region having a side of 5 μm in the filler region. The material region FR (which means that the entire outer periphery (boundary with the electrolyte region) of the filler region FR is within the 5 μm square region) is observed in plan view in the thickness direction of the solid electrolyte layer (solid electrolyte) When the surface perpendicular to the thickness direction of the layer is observed), the ratio of the FR area FA (μm 2 ) to the outer peripheral length FL (μm) of FR satisfies FL / FA ≧ 0.81. It is preferable.
In this plan view observation, the solid electrolyte layer is observed at a magnification of 5000 times using a scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), and is filled in a square region having a side of 5 μm. Ten material regions FR are selected at random. FL / FA in each of these 10 filler regions FR is determined, and when the average of the determined 10 FL / FA is 0.81 or more, FL / FA ≧ 0.81 is satisfied. Note that the number of filler regions to be measured is one in a square region with one side of 5 μm. Satisfaction of FL / FA ≧ 0.81 is an index indicating that the filler region is not a simple particle (spherical), and that the outer periphery of the filler region follows the shape between the inorganic solid electrolyte materials.
FL / FA is preferably 1.0 or more, more preferably 1.5 or more, and further preferably 2.0 or more. Further, FL / FA is usually 100 or less, 50 or less, 20 or less, or 10 or less.
　本発明において、固体電解質層の充填材領域を構成する電子絶縁性材料は、デンドライトの成長をブロックするために、固体状態においてデンドライトよりも硬い材料であることが好ましい。
　上記電子絶縁性材料としては、硫黄、改質硫黄、ヨウ素、硫黄とヨウ素の混合物等を挙げることができ、なかでも硫黄及び／又は改質硫黄を好適に用いることができる。充填材として用いうる硫黄は単体硫黄（硫黄そのもののほか多量体で存在するものも含む。）を意味する。
　また、改質硫黄は、硫黄と改質剤とを混練して得られるものである。例えば、純硫黄と改質添加剤であるオレフィン系化合物とを混練し、硫黄の一部を硫黄ポリマーに改質した改質硫黄を得ることができる。充填材領域に硫黄ないし改質硫黄が存在することにより、この充填材領域へと成長してきたデンドライト（アルカリ金属ないしアルカリ土類金属）を物理的にブロックすることができる。
　また、デンドライトと硫黄とが接触することにより、デンドライトと硫黄との反応も生じ得る。例えば金属リチウムのデンドライトと硫黄とが接触すると、２Ｌｉ＋Ｓ→Ｌｉ２Ｓの反応が生じ、デンドライトの成長が止まる。このような反応が生じると、充填材領域中には反応生成物も共存した状態となる。この反応生成物はデンドライト金属よりも硬い電子絶縁性の化合物であるため、デンドライトの成長をブロックすることができる。すなわち、上記充填材領域は、上記の反応により生じたアルカリ金属を含む化合物及び／又はアルカリ土類金属を含む化合物を含有する形態であることも好ましい。このような形態をとることにより、充填材領域の体積が広がり、充填材領域と電解質領域との間にわずかに残っていた空隙をより確実に塞ぐ効果も期待できる。 In the present invention, the electronic insulating material constituting the filler region of the solid electrolyte layer is preferably a material harder than the dendrite in the solid state in order to block the growth of the dendrite.
Examples of the electronic insulating material include sulfur, modified sulfur, iodine, a mixture of sulfur and iodine, and sulfur and / or modified sulfur can be preferably used. Sulfur that can be used as a filler means elemental sulfur (including sulfur itself as well as multimer).
The modified sulfur is obtained by kneading sulfur and a modifying agent. For example, it is possible to obtain modified sulfur obtained by kneading pure sulfur and an olefinic compound that is a modifying additive, and modifying a part of sulfur into a sulfur polymer. By the presence of sulfur or modified sulfur in the filler region, dendrites (alkali metal or alkaline earth metal) that have grown into the filler region can be physically blocked.
In addition, when the dendrite and sulfur come into contact with each other, a reaction between the dendrite and sulfur can also occur. For example, when the lithium metal dendrite comes into contact with sulfur, a reaction of 2Li + S → Li 2 S occurs, and the dendrite growth stops. When such a reaction occurs, the reaction product also coexists in the filler region. Since this reaction product is an electron insulating compound harder than the dendrite metal, it can block the dendrite growth. That is, it is also preferable that the filler region has a form containing a compound containing an alkali metal and / or a compound containing an alkaline earth metal generated by the above reaction. By taking such a form, the volume of the filler region is expanded, and an effect of more reliably closing the void remaining slightly between the filler region and the electrolyte region can be expected.
　上記充填材領域は、有機バインダーを含有してもよい。有機バインダーを含有することにより、例えば全固体二次電池の製造を、電池シートを巻き取りながら製造するような場合においても、固体電解質と基材となる電極層や集電体との密着性を高めて固体電解質層の欠陥の発生を抑えることが可能となる。また、有機バインダーは、無機固体電解質同士の結着性等も高めることができ、よりまとまりのある層構成とすることができるため好ましい。 The filler region may contain an organic binder. By containing an organic binder, for example, in the case of manufacturing an all-solid secondary battery while winding a battery sheet, the adhesion between the solid electrolyte and the electrode layer or current collector as a base material is improved. It is possible to suppress the occurrence of defects in the solid electrolyte layer. In addition, an organic binder is preferable because it can improve the binding property between inorganic solid electrolytes and can form a more coherent layer structure.
－　有機バインダー　－
　上記有機バインダーとしては有機ポリマーが挙げられる。例えば、以下に述べる樹脂からなる有機バインダーが好ましく使用される。 -Organic binder-
Examples of the organic binder include organic polymers. For example, an organic binder made of the resin described below is preferably used.
　含フッ素樹脂としては、例えば、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリビニレンジフルオリド（ＰＶｄＦ）、ポリビニレンジフルオリドとヘキサフルオロプロピレンとの共重合体（ＰＶｄＦ－ＨＦＰ）が挙げられる。
　炭化水素系熱可塑性樹脂としては、例えば、ポリエチレン、ポリプロピレン、スチレンブタジエンゴム（ＳＢＲ）、水素添加スチレンブタジエンゴム（ＨＳＢＲ）、ブチレンゴム、アクリロニトリル－ブタジエンゴム、ポリブタジエン、ポリイソプレンが挙げられる。
　アクリル樹脂としては、各種の（メタ）アクリルモノマー類、（メタ）アクリルアミドモノマー類、およびこれら樹脂を構成するモノマーの共重合体（好ましくは、アクリル酸とアクリル酸メチルとの共重合体）が挙げられる。
　また、そのほかのビニル系モノマーとの共重合体（コポリマー）も好適に用いられる。例えば、（メタ）アクリル酸メチルとスチレンとの共重合体、（メタ）アクリル酸メチルとアクリロニトリルとの共重合体、（メタ）アクリル酸ブチルとアクリロニトリルとスチレンとの共重合体が挙げられる。本願明細書において、コポリマーは、統計コポリマーおよび周期コポリマーのいずれでもよく、ブロックコポリマーが好ましい。
　その他の樹脂としては例えばポリウレタン樹脂、ポリウレア樹脂、ポリアミド樹脂、ポリイミド樹脂、ポリエステル樹脂、ポリエーテル樹脂、ポリカーボネート樹脂、セルロース誘導体樹脂等が挙げられる。
　これらは１種を単独で用いても、２種以上を組み合わせて用いてもよい。 Examples of the fluorine-containing resin include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), and a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVdF-HFP).
Examples of the hydrocarbon-based thermoplastic resin include polyethylene, polypropylene, styrene butadiene rubber (SBR), hydrogenated styrene butadiene rubber (HSBR), butylene rubber, acrylonitrile-butadiene rubber, polybutadiene, and polyisoprene.
Examples of the acrylic resin include various (meth) acrylic monomers, (meth) acrylamide monomers, and copolymers of these monomers (preferably a copolymer of acrylic acid and methyl acrylate). It is done.
Further, a copolymer (copolymer) with other vinyl monomers is also preferably used. Examples thereof include a copolymer of methyl (meth) acrylate and styrene, a copolymer of methyl (meth) acrylate and acrylonitrile, and a copolymer of butyl (meth) acrylate, acrylonitrile, and styrene. In the present specification, the copolymer may be either a statistical copolymer or a periodic copolymer, and a block copolymer is preferred.
Examples of other resins include polyurethane resin, polyurea resin, polyamide resin, polyimide resin, polyester resin, polyether resin, polycarbonate resin, and cellulose derivative resin.
These may be used individually by 1 type, or may be used in combination of 2 or more type.
　上記有機バインダーは、強い結着性を示す（集電体からの剥離抑制および、固体界面の結着によるサイクル寿命の向上）ため、上述のアクリル樹脂、ポリウレタン樹脂、ポリウレア樹脂、ポリイミド樹脂、含フッ素樹脂および炭化水素系熱可塑性樹脂からなる群から選択される少なくとも１種であることが好ましい。 The above organic binder exhibits strong binding properties (inhibition of peeling from the current collector and improvement in cycle life due to binding at the solid interface), so the above-mentioned acrylic resin, polyurethane resin, polyurea resin, polyimide resin, fluorine-containing material It is preferably at least one selected from the group consisting of a resin and a hydrocarbon-based thermoplastic resin.
　上記有機バインダーは、粒子表面への濡れ性や吸着性を高めるため、極性基を有することが好ましい。極性基とは、ヘテロ原子を含む１価の基、例えば、酸素原子、窒素原子および硫黄原子のいずれかと水素原子が結合した構造を含む１価の基が好ましく、具体例としては、カルボキシ基、ヒドロキシ基、アミノ基、リン酸基およびスルホ基等が挙げられる。 The above organic binder preferably has a polar group in order to improve wettability and adsorptivity to the particle surface. The polar group is preferably a monovalent group containing a hetero atom, for example, a monovalent group containing a structure in which any one of an oxygen atom, a nitrogen atom and a sulfur atom is bonded to a hydrogen atom. Specific examples include a carboxy group, Examples include a hydroxy group, an amino group, a phosphate group, and a sulfo group.
　上記有機バインダーの平均粒子径は、通常１０ｎｍ～３０μｍが好ましく、１０～１０００ｎｍのナノ粒子がより好ましい。 The average particle size of the organic binder is usually preferably 10 nm to 30 μm, and more preferably 10 to 1000 nm nanoparticles.
　上記有機バインダーの重量平均分子量（Ｍｗ）は１０，０００以上が好ましく、２０，０００以上がより好ましく、３０，０００以上がさらに好ましい。上限としては、１，０００，０００以下が好ましく、２００，０００以下がより好ましく、１００，０００以下がさらに好ましい。
　上記充填材領域が有機バインダーを含む場合、固体電解質層中の有機バインダーの含有量として、１～１０質量％が好ましく、２～５質量％がより好ましい。 The weight average molecular weight (Mw) of the organic binder is preferably 10,000 or more, more preferably 20,000 or more, and further preferably 30,000 or more. As an upper limit, 1,000,000 or less is preferable, 200,000 or less is more preferable, and 100,000 or less is more preferable.
When the filler region contains an organic binder, the content of the organic binder in the solid electrolyte layer is preferably 1 to 10% by mass, and more preferably 2 to 5% by mass.
　本発明の全固体二次電池において、固体電解質層の充填材領域は、固体電解質層と正極活物質層との界面には存在しないことが好ましい。電子絶縁性材料（例えば硫黄及び／又は改質硫黄）と正極活物質層とが接触すると、電池容量が低下する場合がある。
　本発明において、充填材領域が固体電解質層と正極活物質層との界面に存在しない、とは、充填材領域が固体電解質層と正極活物質層との界面に事実上存在しないことを意味する。すなわち、電池容量を大きく低下させないレベルで、充填材領域が固体電解質層と正極活物質層との界面に存在する形態を排除するものではない。 In the all solid state secondary battery of the present invention, it is preferable that the filler region of the solid electrolyte layer does not exist at the interface between the solid electrolyte layer and the positive electrode active material layer. When the electronic insulating material (for example, sulfur and / or modified sulfur) and the positive electrode active material layer come into contact with each other, the battery capacity may decrease.
In the present invention, that the filler region does not exist at the interface between the solid electrolyte layer and the positive electrode active material layer means that the filler region does not substantially exist at the interface between the solid electrolyte layer and the positive electrode active material layer. . That is, it does not exclude the form in which the filler region exists at the interface between the solid electrolyte layer and the positive electrode active material layer at a level that does not greatly reduce the battery capacity.
　本発明の二次電池を構成する固体電解質層中、後述する無機固体電解質材料の含有量を１００体積％とした場合、電子絶縁性材料の含有量は１５体積％未満が好ましく、１２体積％未満がより好ましく、１０体積％未満であることも好ましい。電子絶縁性材料をこのような含有量とすることにより、イオンの伝導性をあまり損なわずに、デンドライトの成長を効果的にブロックすることができる。固体電解質層中の無機固体電解質材料の含有量を１００体積％とした場合、電子絶縁性材料の含有量は、通常は２体積％以上であり、５体積％以上が好ましく、７体積％以上がより好ましい。 In the solid electrolyte layer constituting the secondary battery of the present invention, when the content of the inorganic solid electrolyte material described later is 100% by volume, the content of the electronic insulating material is preferably less than 15% by volume, and less than 12% by volume. Is more preferable, and it is also preferable that it is less than 10 volume%. By setting the electronic insulating material to such a content, it is possible to effectively block dendrite growth without significantly impairing the ion conductivity. When the content of the inorganic solid electrolyte material in the solid electrolyte layer is 100% by volume, the content of the electronic insulating material is usually 2% by volume or more, preferably 5% by volume or more, and more preferably 7% by volume or more. More preferred.
（電解質領域）
　本発明の固体電解質層を構成する無機固体電解質材料は、無機固体電解質であるか、あるいは無機固体電解質と活物質との混合物であり、通常は無機固体電解質からなる。無機固体電解質の好ましい形態について以下に説明する。なお、活物質については後述する。 (Electrolyte region)
The inorganic solid electrolyte material constituting the solid electrolyte layer of the present invention is an inorganic solid electrolyte or a mixture of an inorganic solid electrolyte and an active material, and is usually composed of an inorganic solid electrolyte. A preferred form of the inorganic solid electrolyte will be described below. The active material will be described later.
　無機固体電解質とは、無機の固体電解質のことであり、固体電解質とは、その内部においてイオンを移動させることができる固体状の電解質のことである。主たるイオン伝導性材料として有機物を含むものではないことから、有機固体電解質（ポリエチレンオキシド（ＰＥＯ）などに代表される高分子電解質、リチウムビス（トリフルオロメタンスルホニル）イミド（ＬｉＴＦＳＩ）などに代表される有機電解質塩）とは明確に区別される。また、無機固体電解質は定常状態では固体であるため、通常カチオンおよびアニオンに解離または遊離していない。この点で、電解液やポリマー中でカチオンおよびアニオンが解離または遊離している無機電解質塩（ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＦＳＩ、ＬｉＣｌなど）とも明確に区別される。無機固体電解質は周期律表第１族または第２族に属する金属のイオンの伝導性を有するものであれば特に限定されず電子伝導性を有さないものが一般的である。 The inorganic solid electrolyte is an inorganic solid electrolyte, and the solid electrolyte is a solid electrolyte capable of moving ions inside. Since it does not contain organic substances as the main ion conductive material, organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO), etc., organics typified by lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), etc. It is clearly distinguished from the electrolyte salt). In addition, since the inorganic solid electrolyte is solid in a steady state, it is not usually dissociated or released into cations and anions. In this respect, it is also clearly distinguished from inorganic electrolyte salts (such as LiPF 6 , LiBF 4 , LiFSI, LiCl, etc.) in which cations and anions are dissociated or liberated in the electrolyte or polymer. The inorganic solid electrolyte is not particularly limited as long as it has conductivity of ions of metals belonging to Group 1 or Group 2 of the periodic table, and generally does not have electron conductivity.
　本発明において、無機固体電解質は、周期律表第１族または第２族に属する金属のイオン伝導性を有する。上記無機固体電解質は、この種の製品に適用される固体電解質材料を適宜選定して用いることができる。無機固体電解質として、一般的には（ｉ）硫化物系無機固体電解質及び／又は（ｉｉ）酸化物系無機固体電解質が用いられる。 In the present invention, the inorganic solid electrolyte has ion conductivity of a metal belonging to Group 1 or Group 2 of the periodic table. As the inorganic solid electrolyte, a solid electrolyte material applied to this type of product can be appropriately selected and used. In general, (i) a sulfide-based inorganic solid electrolyte and / or (ii) an oxide-based inorganic solid electrolyte is used as the inorganic solid electrolyte.
（ｉ）硫化物系無機固体電解質
　硫化物系無機固体電解質は、硫黄原子（Ｓ）を含有し、かつ、周期律表第１族または第２族に属する金属のイオン伝導性を有し、かつ、電子絶縁性を有するものが好ましい。硫化物系無機固体電解質は、元素として少なくともＬｉ、ＳおよびＰを含有し、リチウムイオン伝導性を有しているものが好ましいが、目的または場合に応じて、Ｌｉ、ＳおよびＰ以外の他の元素を含んでもよい。
　例えば下記式（Ｉ）で示される組成を満たすリチウムイオン伝導性無機固体電解質が挙げられる。
 
　　　Ｌａ１Ｍｂ１Ｐｃ１Ｓｄ１Ａｅ１　式（Ｉ）
 
　式中、ＬはＬｉ、ＮａおよびＫから選択される元素を示し、Ｌｉが好ましい。Ｍは、Ｂ、Ｚｎ、Ｓｎ、Ｓｉ、Ｃｕ、Ｇａ、Ｓｂ、Ａｌ及びＧｅから選択される元素を示す。Ａは、Ｉ、Ｂｒ、Ｃｌ及びＦから選択される元素を示す。ａ１～ｅ１は各元素の組成比を示し、ａ１：ｂ１：ｃ１：ｄ１：ｅ１は１～１２：０～５：１：２～１２：０～１０を満たす。ａ１はさらに、１～９が好ましく、１．５～７．５がより好ましい。ｂ１は０～３が好ましい。ｄ１はさらに、２．５～１０が好ましく、３．０～８．５がより好ましい。ｅ１はさらに、０～５が好ましく、０～３がより好ましい。 (I) Sulfide-based inorganic solid electrolyte The sulfide-based inorganic solid electrolyte contains a sulfur atom (S) and has ion conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and Those having electronic insulating properties are preferred. The sulfide-based inorganic solid electrolyte preferably contains at least Li, S and P as elements and has lithium ion conductivity. However, depending on the purpose or the case, other than Li, S and P may be used. An element may be included.
For example, a lithium ion conductive inorganic solid electrolyte satisfying the composition represented by the following formula (I) can be mentioned.

L a1 M b1 P c1 S d1 A e1 Formula (I)

In the formula, L represents an element selected from Li, Na and K, and Li is preferred. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, and Ge. A represents an element selected from I, Br, Cl and F. a1 to e1 indicate the composition ratio of each element, and a1: b1: c1: d1: e1 satisfies 1 to 12: 0 to 5: 1: 2 to 12: 0 to 10. a1 is further preferably 1 to 9, and more preferably 1.5 to 7.5. b1 is preferably 0 to 3. Further, d1 is preferably 2.5 to 10, and more preferably 3.0 to 8.5. Further, e1 is preferably 0 to 5, and more preferably 0 to 3.
　各元素の組成比は、下記のように、硫化物系無機固体電解質を製造する際の原料化合物の配合量を調整することにより制御できる。 The composition ratio of each element can be controlled by adjusting the blending amount of the raw material compound when producing the sulfide-based inorganic solid electrolyte as described below.
　硫化物系無機固体電解質は、非結晶（ガラス）であっても結晶化（ガラスセラミックス化）していてもよく、一部のみが結晶化していてもよい。例えば、Ｌｉ、ＰおよびＳを含有するＬｉ－Ｐ－Ｓ系ガラス、またはＬｉ、ＰおよびＳを含有するＬｉ－Ｐ－Ｓ系ガラスセラミックスを用いることができる。
　硫化物系無機固体電解質は、例えば硫化リチウム（Ｌｉ２Ｓ）、硫化リン（例えば五硫化二燐（Ｐ２Ｓ５））、単体燐、単体硫黄、硫化ナトリウム、硫化水素、ハロゲン化リチウム（例えばＬｉＩ、ＬｉＢｒ、ＬｉＣｌ）及び上記Ｍであらわされる元素の硫化物（例えばＳｉＳ２、ＳｎＳ、ＧｅＳ２）の中の少なくとも２つ以上の原料の反応により製造することができる。 The sulfide-based inorganic solid electrolyte may be amorphous (glass) or crystallized (glass ceramic), or only a part may be crystallized. For example, Li—PS system glass containing Li, P and S, or Li—PS system glass ceramics containing Li, P and S can be used.
The sulfide-based inorganic solid electrolyte includes, for example, lithium sulfide (Li 2 S), phosphorus sulfide (for example, diphosphorus pentasulfide (P 2 S 5 )), simple phosphorus, simple sulfur, sodium sulfide, hydrogen sulfide, lithium halide (for example, LiI, LiBr, LiCl) and a sulfide of an element represented by M (for example, SiS 2 , SnS, GeS 2 ) can be produced by reaction of at least two raw materials.
　Ｌｉ－Ｐ－Ｓ系ガラスおよびＬｉ－Ｐ－Ｓ系ガラスセラミックスにおける、Ｌｉ２ＳとＰ２Ｓ５との比率は、Ｌｉ２Ｓ：Ｐ２Ｓ５のモル比で、好ましくは６０：４０～９０：１０、より好ましくは６８：３２～７８：２２である。Ｌｉ２ＳとＰ２Ｓ５との比率をこの範囲にすることにより、リチウムイオン伝導度を高いものとすることができる。具体的には、リチウムイオン伝導度を好ましくは１×１０－４Ｓ／ｃｍ以上、より好ましくは１×１０－３Ｓ／ｃｍ以上とすることができる。上限は特にないが、１×１０－１Ｓ／ｃｍ以下であることが実際的である。 The ratio of Li 2 S and P 2 S 5 in the Li—PS system glass and Li—PS system glass ceramic is a molar ratio of Li 2 S: P 2 S 5 , preferably 60:40 to 90:10, more preferably 68:32 to 78:22. By setting the ratio of Li 2 S to P 2 S 5 within this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity can be preferably 1 × 10 −4 S / cm or more, more preferably 1 × 10 −3 S / cm or more. Although there is no particular upper limit, it is practical that it is 1 × 10 −1 S / cm or less.
　具体的な硫化物系無機固体電解質の例として、原料の組み合わせ例を下記に示す。たとえばＬｉ２Ｓ－Ｐ２Ｓ５、Ｌｉ２Ｓ－Ｐ２Ｓ５－ＬｉＣｌ、Ｌｉ２Ｓ－Ｐ２Ｓ５－Ｈ２Ｓ、Ｌｉ２Ｓ－Ｐ２Ｓ５－Ｈ２Ｓ－ＬｉＣｌ、Ｌｉ２Ｓ－ＬｉＩ－Ｐ２Ｓ５、Ｌｉ２Ｓ－ＬｉＩ－Ｌｉ２Ｏ－Ｐ２Ｓ５、Ｌｉ２Ｓ－ＬｉＢｒ－Ｐ２Ｓ５、Ｌｉ２Ｓ－Ｌｉ２Ｏ－Ｐ２Ｓ５、Ｌｉ２Ｓ－Ｌｉ３ＰＯ４－Ｐ２Ｓ５、Ｌｉ２Ｓ－Ｐ２Ｓ５－Ｐ２Ｏ５、Ｌｉ２Ｓ－Ｐ２Ｓ５－ＳｉＳ２、Ｌｉ２Ｓ－Ｐ２Ｓ５－ＳｉＳ２－ＬｉＣｌ、Ｌｉ２Ｓ－Ｐ２Ｓ５－ＳｎＳ、Ｌｉ２Ｓ－Ｐ２Ｓ５－Ａｌ２Ｓ３、Ｌｉ２Ｓ－ＧｅＳ２、Ｌｉ２Ｓ－ＧｅＳ２－ＺｎＳ、Ｌｉ２Ｓ－Ｇａ２Ｓ３、Ｌｉ２Ｓ－ＧｅＳ２－Ｇａ２Ｓ３、Ｌｉ２Ｓ－ＧｅＳ２－Ｐ２Ｓ５、Ｌｉ２Ｓ－ＧｅＳ２－Ｓｂ２Ｓ５、Ｌｉ２Ｓ－ＧｅＳ２－Ａｌ２Ｓ３、Ｌｉ２Ｓ－ＳｉＳ２、Ｌｉ２Ｓ－Ａｌ２Ｓ３、Ｌｉ２Ｓ－ＳｉＳ２－Ａｌ２Ｓ３、Ｌｉ２Ｓ－ＳｉＳ２－Ｐ２Ｓ５、Ｌｉ２Ｓ－ＳｉＳ２－Ｐ２Ｓ５－ＬｉＩ、Ｌｉ２Ｓ－ＳｉＳ２－ＬｉＩ、Ｌｉ２Ｓ－ＳｉＳ２－Ｌｉ４ＳｉＯ４、Ｌｉ２Ｓ－ＳｉＳ２－Ｌｉ３ＰＯ４、Ｌｉ１０ＧｅＰ２Ｓ１２などが挙げられる。ただし、各原料の混合比は問わない。このような原料組成物を用いて硫化物系無機固体電解質材料を合成する方法としては、例えば非晶質化法を挙げることができる。非晶質化法としては、例えば、メカニカルミリング法、溶液法および溶融急冷法を挙げられる。常温での処理が可能になり、製造工程の簡略化を図ることができるからである。 Examples of combinations of raw materials are shown below as specific examples of sulfide-based inorganic solid electrolytes. For example, Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiCl, Li 2 S—P 2 S 5 —H 2 S, Li 2 S—P 2 S 5 —H 2 S—LiCl, Li 2 S—LiI—P 2 S 5 , Li 2 S—LiI—Li 2 O—P 2 S 5 , Li 2 S—LiBr—P 2 S 5 , Li 2 S—Li 2 O—P 2 S 5 , Li 2 S—Li 3 PO 4 —P 2 S 5 , Li 2 S—P 2 S 5 —P 2 O 5 , Li 2 S—P 2 S 5 —SiS 2 , Li 2 S—P 2 S 5 —SiS 2 —LiCl, Li 2 S—P 2 S 5 —SnS, Li 2 S—P 2 S 5 —Al 2 S 3 , Li 2 S—GeS 2 , Li 2 S—GeS 2 —ZnS, Li 2 S—Ga 2 S 3, Li 2 S-GeS 2 -Ga 2 S 3, Li 2 S-GeS 2 -P 2 S 5 Li 2 S-GeS 2 -Sb 2 S 5, Li 2 S-GeS 2 -Al 2 S 3, Li 2 S-SiS 2, Li 2 S-Al 2 S 3, Li 2 S-SiS 2 -Al 2 S 3 , Li 2 S—SiS 2 —P 2 S 5 , Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —Li 4 SiO 4 , Li 2 S—SiS 2 —Li 3 PO 4 , Li 10 GeP 2 S 12 and the like. However, the mixing ratio of each raw material does not matter. Examples of a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition include an amorphization method. Examples of the amorphization method include a mechanical milling method, a solution method, and a melt quench method. This is because processing at room temperature is possible, and the manufacturing process can be simplified.
（ｉｉ）酸化物系無機固体電解質
　酸化物系無機固体電解質は、酸素原子（Ｏ）を含有し、かつ、周期律表第１族または第２族に属する金属のイオン伝導性を有し、かつ、電子絶縁性を有する化合物が好ましい。 (Ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte contains an oxygen atom (O) and has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and A compound having an electronic insulating property is preferable.
　具体的な化合物例としては、例えばＬｉｘａＬａｙａＴｉＯ３〔ｘａ＝０．３～０．７、ｙａ＝０．３～０．７〕（ＬＬＴ）、ＬｉｘｂＬａｙｂＺｒｚｂＭｂｂ ｍｂＯｎｂ（ＭｂｂはＡｌ，Ｍｇ，Ｃａ，Ｓｒ，Ｖ，Ｎｂ，Ｔａ，Ｔｉ，Ｇｅ，Ｉｎ，Ｓｎの少なくとも１種以上の元素でありｘｂは５≦ｘｂ≦１０を満たし、ｙｂは１≦ｙｂ≦４を満たし、ｚｂは１≦ｚｂ≦４を満たし、ｍｂは０≦ｍｂ≦２を満たし、ｎｂは５≦ｎｂ≦２０を満たす。）、ＬｉｘｃＢｙｃＭｃｃ ｚｃＯｎｃ（ＭｃｃはＣ，Ｓ，Ａｌ，Ｓｉ，Ｇａ，Ｇｅ，Ｉｎ，Ｓｎの少なくとも１種以上の元素でありｘｃは０≦ｘｃ≦５を満たし、ｙｃは０≦ｙｃ≦１を満たし、ｚｃは０≦ｚｃ≦１を満たし、ｎｃは０≦ｎｃ≦６を満たす。）、Ｌｉｘｄ（Ａｌ，Ｇａ）ｙｄ（Ｔｉ，Ｇｅ）ｚｄＳｉａｄＰｍｄＯｎｄ（ただし、１≦ｘｄ≦３、０≦ｙｄ≦１、０≦ｚｄ≦２、０≦ａｄ≦１、１≦ｍｄ≦７、３≦ｎｄ≦１３）、Ｌｉ（３－２ｘｅ）Ｍｅｅ ｘｅＤｅｅＯ（ｘｅは０以上０．１以下の数を表し、Ｍｅｅは２価の金属原子を表す。Ｄｅｅはハロゲン原子または２種以上のハロゲン原子の組み合わせを表す。）、ＬｉｘｆＳｉｙｆＯｚｆ（１≦ｘｆ≦５、０＜ｙｆ≦３、１≦ｚｆ≦１０）、ＬｉｘｇＳｙｇＯｚｇ（１≦ｘｇ≦３、０＜ｙｇ≦２、１≦ｚｇ≦１０）、Ｌｉ３ＢＯ３－Ｌｉ２ＳＯ４、Ｌｉ２Ｏ－Ｂ２Ｏ３－Ｐ２Ｏ５、Ｌｉ２Ｏ－ＳｉＯ２、Ｌｉ６ＢａＬａ２Ｔａ２Ｏ１２、Ｌｉ３ＰＯ（４－３／２ｗ）Ｎｗ（ｗはｗ＜１）、ＬＩＳＩＣＯＮ（Ｌｉｔｈｉｕｍ　ｓｕｐｅｒ　ｉｏｎｉｃ　ｃｏｎｄｕｃｔｏｒ）型結晶構造を有するＬｉ３．５Ｚｎ０．２５ＧｅＯ４、ペロブスカイト型結晶構造を有するＬａ０．５５Ｌｉ０．３５ＴｉＯ３、ＮＡＳＩＣＯＮ（Ｎａｔｒｉｕｍ　ｓｕｐｅｒ　ｉｏｎｉｃ　ｃｏｎｄｕｃｔｏｒ）型結晶構造を有するＬｉＴｉ２Ｐ３Ｏ１２、Ｌｉ１＋ｘｈ＋ｙｈ（Ａｌ，Ｇａ）ｘｈ（Ｔｉ，Ｇｅ）２－ｘｈＳｉｙｈＰ３－ｙｈＯ１２（ただし、０≦ｘｈ≦１、０≦ｙｈ≦１）、ガーネット型結晶構造を有するＬｉ７Ｌａ３Ｚｒ２Ｏ１２（ＬＬＺ）等が挙げられる。またＬｉ、Ｐ及びＯを含むリン化合物も望ましい。例えばリン酸リチウム（Ｌｉ３ＰＯ４）、リン酸リチウムの酸素の一部を窒素で置換したＬｉＰＯＮ、ＬｉＰＯＤ１（Ｄ１は、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ａｇ、Ｔａ、Ｗ、Ｐｔ、Ａｕ等から選ばれた少なくとも１種）等が挙げられる。また、ＬｉＡ１ＯＮ（Ａ１は、Ｓｉ、Ｂ、Ｇｅ、Ａｌ、Ｃ、Ｇａ等から選ばれた少なくとも１種）等も好ましく用いることができる。 Specific examples of the compound include Li xa La ya TiO 3 [xa = 0.3 to 0.7, ya = 0.3 to 0.7] (LLT), Li xb La yb Zr zb M bb mb O nb ( Mbb is at least one element selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, xb satisfies 5 ≦ xb ≦ 10, and yb satisfies 1 ≦ yb. ≦ 4, zb satisfies 1 ≦ zb ≦ 4, mb satisfies 0 ≦ mb ≦ 2, nb satisfies 5 ≦ nb ≦ 20), Li xc B yc M cc zc Onc (M cc is C, S, Al, Si, Ga, Ge, In, Sn are at least one element, xc satisfies 0 ≦ xc ≦ 5, yc satisfies 0 ≦ yc ≦ 1, and zc satisfies 0 ≦ zc ≦ met 1, nc satisfies 0 ≦ nc ≦ 6.), Li xd ( l, Ga) yd (Ti, Ge) zd Si ad P md O nd ( provided that, 1 ≦ xd ≦ 3,0 ≦ yd ≦ 1,0 ≦ zd ≦ 2,0 ≦ ad ≦ 1,1 ≦ md ≦ 7, 3 ≦ nd ≦ 13), Li (3-2xe) M ee xe D ee O (xe represents a number from 0 to 0.1, and M ee represents a divalent metal atom. D ee represents a halogen atom or Represents a combination of two or more halogen atoms.), Li xf Si yf O zf (1 ≦ xf ≦ 5, 0 <yf ≦ 3, 1 ≦ zf ≦ 10), Li xg S yg O zg (1 ≦ xg ≦ 3, 0 <yg ≦ 2, 1 ≦ zg ≦ 10), Li 3 BO 3 —Li 2 SO 4 , Li 2 O—B 2 O 3 —P 2 O 5 , Li 2 O—SiO 2 , Li 6 BaLa 2 ta 2 O 12, Li 3 PO (4-3 / 2w) N w (w is w <1), LI ICON (Lithium super ionic conductor) type Li 3.5 Zn 0.25 GeO 4 having a crystal structure, La 0.55 Li 0.35 TiO 3 having a perovskite crystal structure, NASICON (Natrium super ionic conductor) type crystal structure LiTi 2 P 3 O 12 , Li 1 + xh + yh (Al, Ga) xh (Ti, Ge) 2-xh Si yh P 3-yh O 12 (where 0 ≦ xh ≦ 1, 0 ≦ yh ≦ 1), garnet Examples include Li 7 La 3 Zr 2 O 12 (LLZ) having a type crystal structure. Phosphorus compounds containing Li, P and O are also desirable. For example, lithium phosphate (Li 3 PO 4 ), LiPON obtained by replacing a part of oxygen of lithium phosphate with nitrogen, LiPOD 1 (D 1 is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr) , Nb, Mo, Ru, Ag, Ta, W, Pt, Au, etc.). LiA 1 ON (A 1 is at least one selected from Si, B, Ge, Al, C, Ga, etc.) and the like can also be preferably used.
　無機固体電解質の粒子径（体積平均粒子径）は特に限定されないが、０．０１μｍ以上であることが好ましく、０．１μｍ以上であることがより好ましい。上限としては、１００μｍ以下であることが好ましく、５０μｍ以下であることがより好ましい。なお、無機固体電解質粒子の平均粒子径の測定は、以下の手順で行う。無機固体電解質粒子を、水（水に不安定な物質の場合はヘプタン）を用いて２０ｍｌサンプル瓶中で１質量％の分散液を希釈調整する。希釈後の分散試料は、１ｋＨｚの超音波を１０分間照射し、その直後に試験に使用する。この分散液試料を用い、レーザ回折／散乱式粒度分布測定装置ＬＡ－９２０（ＨＯＲＩＢＡ社製）を用いて、温度２５℃で測定用石英セルを使用してデータ取り込みを５０回行い、体積平均粒子径を得る。その他の詳細な条件等は必要によりＪＩＳＺ８８２８：２０１３「粒子径解析－動的光散乱法」の記載を参照する。１水準につき５つの試料を作製しその平均値を採用する。 The particle diameter (volume average particle diameter) of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. As an upper limit, it is preferable that it is 100 micrometers or less, and it is more preferable that it is 50 micrometers or less. In addition, the measurement of the average particle diameter of an inorganic solid electrolyte particle is performed in the following procedures. The inorganic solid electrolyte particles are diluted and adjusted in a 20 ml sample bottle using water (heptane in the case of a substance unstable to water). The diluted dispersion sample is irradiated with 1 kHz ultrasonic waves for 10 minutes and used immediately after that. Using this dispersion liquid sample, using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA), data acquisition was performed 50 times using a measurement quartz cell at a temperature of 25 ° C. Get the diameter. For other detailed conditions, the description of JISZ8828: 2013 “Particle Size Analysis—Dynamic Light Scattering Method” is referred to as necessary. Five samples are prepared for each level, and the average value is adopted.
　本発明において無機固体電解質材料は、大粒径の粒子とそれより小粒径の粒子とが混在し、［大粒径粒子の粒子径］＞４×［小粒径粒子の粒子径］を満たす粒子が存在する粒度分布を有することが好ましい。このような粒度分布を有することにより、上述のＦＬ／ＦＡをより高めることができる。すなわち、無機固体電解質材料間の空隙をより低減することができ、かつ、この空隙に充填材が、より隙間なく充填された形態とすることができる。 In the present invention, the inorganic solid electrolyte material is a mixture of particles having a large particle size and particles having a smaller particle size, and satisfies [particle size of large particle size]> 4 × [particle size of small particle size]. It is preferable to have a particle size distribution in which the particles are present. By having such a particle size distribution, the above-mentioned FL / FA can be further increased. That is, the space | gap between inorganic solid electrolyte materials can be reduced more, and it can be set as the form with which the filler was filled more without gap in this space | gap.
＜正極活物質層＞
　上記正極活物質層４は、上述した無機固体電解質と、正極活物質とを含有する。
　正極活物質の好ましい形態について説明する。 <Positive electrode active material layer>
The positive electrode active material layer 4 contains the inorganic solid electrolyte described above and a positive electrode active material.
A preferred form of the positive electrode active material will be described.
（正極活物質）
　正極活物質は、可逆的にリチウムイオンを挿入および放出できるものが好ましい。その材料は、上記特性を有するものであれば、特に制限はなく、遷移金属酸化物や、有機物、硫黄などのＬｉと複合化できる元素や硫黄と金属の複合物などでもよい。
　中でも、正極活物質としては、遷移金属酸化物を用いることが好ましく、遷移金属元素Ｍａ（Ｃｏ、Ｎｉ、Ｆｅ、Ｍｎ、ＣｕおよびＶから選択される１種以上の元素）を有する遷移金属酸化物がより好ましい。また、この遷移金属酸化物に元素Ｍｂ（リチウム以外の金属周期律表の第１（Ｉａ）族の元素、第２（ＩＩａ）族の元素、Ａｌ、Ｇａ、Ｉｎ、Ｇｅ、Ｓｎ、Ｐｂ、Ｓｂ、Ｂｉ、Ｓｉ、ＰまたはＢなどの元素）を混合してもよい。混合量としては、遷移金属元素Ｍａの量（１００ｍｏｌ％）に対して０～３０ｍｏｌ％が好ましい。Ｌｉ／Ｍａのモル比が０．３～２．２になるように混合して合成されたものが、より好ましい。
　遷移金属酸化物の具体例としては、（ＭＡ）層状岩塩型構造を有する遷移金属酸化物、（ＭＢ）スピネル型構造を有する遷移金属酸化物、（ＭＣ）リチウム含有遷移金属リン酸化合物、（ＭＤ）リチウム含有遷移金属ハロゲン化リン酸化合物および（ＭＥ）リチウム含有遷移金属ケイ酸化合物等が挙げられる。 (Positive electrode active material)
The positive electrode active material is preferably one that can reversibly insert and release lithium ions. The material is not particularly limited as long as it has the above characteristics, and may be a transition metal oxide, an organic substance, an element that can be complexed with Li, such as sulfur, or a complex of sulfur and metal.
Among them, as the positive electrode active material, it is preferable to use a transition metal oxide, and a transition metal oxide having a transition metal element M a (one or more elements selected from Co, Ni, Fe, Mn, Cu and V). More preferred. In addition, this transition metal oxide includes an element M b (an element of the first (Ia) group of the metal periodic table other than lithium, an element of the second (IIa) group, Al, Ga, In, Ge, Sn, Pb, Elements such as Sb, Bi, Si, P or B) may be mixed. The mixing amount is preferably 0 ~ 30 mol% relative to the amount of the transition metal element M a (100mol%). Those synthesized by mixing so that the molar ratio of Li / Ma is 0.3 to 2.2 are more preferable.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt structure, (MB) a transition metal oxide having a spinel structure, (MC) a lithium-containing transition metal phosphate compound, (MD And lithium-containing transition metal halide phosphate compounds and (ME) lithium-containing transition metal silicate compounds.
　（ＭＡ）層状岩塩型構造を有する遷移金属酸化物の具体例として、ＬｉＣｏＯ２（コバルト酸リチウム［ＬＣＯ］）、ＬｉＮｉ２Ｏ２（ニッケル酸リチウム）ＬｉＮｉ０．８５Ｃｏ０．１０Ａｌ０．０５Ｏ２（ニッケルコバルトアルミニウム酸リチウム［ＮＣＡ］）、ＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２（ニッケルマンガンコバルト酸リチウム［ＮＭＣ］）およびＬｉＮｉ０．５Ｍｎ０．５Ｏ２（マンガンニッケル酸リチウム）が挙げられる。
　（ＭＢ）スピネル型構造を有する遷移金属酸化物の具体例として、ＬｉＭｎ２Ｏ４（ＬＭＯ）、ＬｉＣｏＭｎＯ４、Ｌｉ２ＦｅＭｎ３Ｏ８、Ｌｉ２ＣｕＭｎ３Ｏ８、Ｌｉ２ＣｒＭｎ３Ｏ８およびＬｉ２ＮｉＭｎ３Ｏ８が挙げられる。　（ＭＣ）リチウム含有遷移金属リン酸化合物としては、例えば、ＬｉＦｅＰＯ４およびＬｉ３Ｆｅ２（ＰＯ４）３等のオリビン型リン酸鉄塩、ＬｉＦｅＰ２Ｏ７等のピロリン酸鉄類、ＬｉＣｏＰＯ４等のリン酸コバルト類ならびにＬｉ３Ｖ２（ＰＯ４）３（リン酸バナジウムリチウム）等の単斜晶ナシコン型リン酸バナジウム塩が挙げられる。
　（ＭＤ）リチウム含有遷移金属ハロゲン化リン酸化合物としては、例えば、Ｌｉ２ＦｅＰＯ４Ｆ等のフッ化リン酸鉄塩、Ｌｉ２ＭｎＰＯ４Ｆ等のフッ化リン酸マンガン塩およびＬｉ２ＣｏＰＯ４Ｆ等のフッ化リン酸コバルト類が挙げられる。
　（ＭＥ）リチウム含有遷移金属ケイ酸化合物としては、例えば、Ｌｉ２ＦｅＳｉＯ４、Ｌｉ２ＭｎＳｉＯ４およびＬｉ２ＣｏＳｉＯ４等が挙げられる。
　本発明では、（ＭＡ）層状岩塩型構造を有する遷移金属酸化物が好ましく、ＬＣＯ、ＬＭＯ、ＮＣＡ又はＮＭＣがより好ましい。 Specific examples of the transition metal oxides having (MA) layered rock-salt structure, LiCoO 2 (lithium cobaltate [LCO]), LiNi 2 O 2 ( lithium nickelate) LiNi 0.85 Co 0.10 Al 0.05 O 2 (lithium nickel cobalt aluminate [NCA]), LiNi 1/3 Co 1/3 Mn 1/3 O 2 (nickel manganese lithium cobaltate [NMC]) and LiNi 0.5 Mn 0.5 O 2 (manganese) Lithium nickelate).
Specific examples of transition metal oxides having (MB) spinel structure include LiMn 2 O 4 (LMO), LiCoMnO 4, Li 2 FeMn 3 O 8 , Li 2 CuMn 3 O 8 , Li 2 CrMn 3 O 8 and Li 2 NiMn 3 O 8 is mentioned. Examples of (MC) lithium-containing transition metal phosphate compounds include olivine-type phosphate iron salts such as LiFePO 4 and Li 3 Fe 2 (PO 4 ) 3 , iron pyrophosphates such as LiFeP 2 O 7 , LiCoPO 4, and the like. And monoclinic Nasicon type vanadium phosphate salts such as Li 3 V 2 (PO 4 ) 3 (vanadium lithium phosphate).
(MD) as the lithium-containing transition metal halogenated phosphate compound, for example, Li 2 FePO 4 F such fluorinated phosphorus iron salt, Li 2 MnPO 4 hexafluorophosphate manganese salts such as F and Li 2 CoPO 4 F Cobalt fluorophosphates such as
Examples of the (ME) lithium-containing transition metal silicate compound include Li 2 FeSiO 4 , Li 2 MnSiO 4, and Li 2 CoSiO 4 .
In the present invention, a transition metal oxide having a (MA) layered rock salt structure is preferable, and LCO, LMO, NCA or NMC is more preferable.
　正極活物質の形状は特に制限されないが粒子状が好ましい。正極活物質の体積平均粒子径（球換算平均粒子径）は特に限定されない。例えば、０．１～５０μｍとすることができる。正極活物質を所定の粒子径にするには、通常の粉砕機や分級機を用いればよい。焼成法によって得られた正極活物質は、水、酸性水溶液、アルカリ性水溶液、有機溶剤にて洗浄した後使用してもよい。正極活物質粒子の体積平均粒子径（球換算平均粒子径）は、レーザ回折／散乱式粒度分布測定装置ＬＡ－９２０（商品名、ＨＯＲＩＢＡ社製）を用いて測定することができる。 The shape of the positive electrode active material is not particularly limited, but is preferably particulate. The volume average particle diameter (sphere conversion average particle diameter) of the positive electrode active material is not particularly limited. For example, the thickness can be 0.1 to 50 μm. In order to make the positive electrode active material have a predetermined particle size, an ordinary pulverizer or classifier may be used. The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent. The volume average particle diameter (sphere-converted average particle diameter) of the positive electrode active material particles can be measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA).
　上記正極活物質は、１種を単独で用いても、２種以上を組み合わせて用いてもよい。
　正極活物質層を形成する場合、正極活物質層の単位面積（ｃｍ２）当たりの正極活物質の質量（ｍｇ）（目付量）は特に限定されるものではない。設計された電池容量に応じて、適宜に決めることができる。 The positive electrode active materials may be used alone or in combination of two or more.
When forming the positive electrode active material layer, the mass (mg) (weight per unit area) of the positive electrode active material per unit area (cm 2 ) of the positive electrode active material layer is not particularly limited. This can be determined as appropriate according to the designed battery capacity.
　正極活物質の、固体電解質組成物中における含有量は、特に限定されず、固形分１００質量％において、１０～９５質量％が好ましく、３０～９０質量％がより好ましく、５０～８５質量がさらに好ましく、５５～８０質量％が特に好ましい。 The content of the positive electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 95% by mass, more preferably 30 to 90% by mass, and even more preferably 50 to 85% by mass at 100% by mass. Preferably, it is 55 to 80% by mass.
＜負極活物質層＞
　上記負極活物質層２は、上述した無機固体電解質と、負極活物質とを含有する。なお、上述した通り、本発明の全固体二次電池は負極活物質層を予め形成しない形態とすることも好ましい。
　負極活物質の好ましい形態について説明する。 <Negative electrode active material layer>
The negative electrode active material layer 2 contains the inorganic solid electrolyte described above and a negative electrode active material. Note that, as described above, the all solid state secondary battery of the present invention preferably has a configuration in which the negative electrode active material layer is not formed in advance.
A preferred form of the negative electrode active material will be described.
（負極活物質）
　負極活物質は、可逆的にリチウムイオンを挿入および放出できるものが好ましい。その材料は、上記特性を有するものであれば、特に制限はなく、炭素質材料、酸化錫等の金属酸化物、酸化ケイ素、金属複合酸化物、リチウム単体およびリチウムアルミニウム合金等のリチウム合金、並びに、Ｓｎ、Ｓｉ、ＡｌおよびＩｎ等のリチウムと合金形成可能な金属等が挙げられる。中でも、炭素質材料又はリチウム複合酸化物が信頼性の点から好ましく用いられる。また、金属複合酸化物としては、リチウムを吸蔵および放出可能であることが好ましい。その材料は、特には制限されないが、構成成分としてチタン及び／又はリチウムを含有していることが、高電流密度充放電特性の観点で好ましい。 (Negative electrode active material)
The negative electrode active material is preferably one that can reversibly insert and release lithium ions. The material is not particularly limited as long as it has the above characteristics, and is a carbonaceous material, a metal oxide such as tin oxide, a silicon oxide, a metal composite oxide, a lithium simple substance and a lithium alloy such as a lithium aluminum alloy, and , Metals such as Sn, Si, Al, and In that can form an alloy with lithium. Among these, a carbonaceous material or a lithium composite oxide is preferably used from the viewpoint of reliability. The metal composite oxide is preferably capable of inserting and extracting lithium. The material is not particularly limited, but preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.
　負極活物質として用いられる炭素質材料とは、実質的に炭素からなる材料である。例えば、石油ピッチ、アセチレンブラック（ＡＢ）等のカーボンブラック、黒鉛（天然黒鉛、気相成長黒鉛等の人造黒鉛等）、及びＰＡＮ（ポリアクリロニトリル）系の樹脂やフルフリルアルコール樹脂等の各種の合成樹脂を焼成した炭素質材料を挙げることができる。さらに、ＰＡＮ系炭素繊維、セルロース系炭素繊維、ピッチ系炭素繊維、気相成長炭素繊維、脱水ＰＶＡ（ポリビニルアルコール）系炭素繊維、リグニン炭素繊維、ガラス状炭素繊維および活性炭素繊維等の各種炭素繊維類、メソフェーズ微小球体、グラファイトウィスカーならびに平板状の黒鉛等を挙げることもできる。 The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. For example, various synthetics such as petroleum pitch, carbon black such as acetylene black (AB), graphite (natural graphite, artificial graphite such as vapor-grown graphite), PAN (polyacrylonitrile) -based resin, furfuryl alcohol resin, etc. The carbonaceous material which baked resin can be mentioned. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA (polyvinyl alcohol) -based carbon fiber, lignin carbon fiber, glassy carbon fiber, and activated carbon fiber. Examples thereof include mesophase microspheres, graphite whiskers, and flat graphite.
　負極活物質として適用される金属酸化物及び金属複合酸化物としては、特に非晶質酸化物が好ましく、さらに金属元素と周期律表第１６族の元素との反応生成物であるカルコゲナイトも好ましく用いられる。ここでいう非晶質とは、ＣｕＫα線を用いたＸ線回折法で、２θ値で２０°～４０°の領域に頂点を有するブロードな散乱帯を有するものを意味し、結晶性の回折線を有してもよい。 As the metal oxide and metal composite oxide applied as the negative electrode active material, an amorphous oxide is particularly preferable, and chalcogenite, which is a reaction product of a metal element and an element of Group 16 of the periodic table, is also preferably used. It is done. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having a peak in the region of 20 ° to 40 ° in terms of 2θ, and is a crystalline diffraction line. You may have.
　上記非晶質酸化物及びカルコゲナイドからなる化合物群の中でも、半金属元素の非晶質酸化物、及びカルコゲナイドがより好ましく、周期律表第１３（ＩＩＩＢ）族～１５（ＶＢ）族の元素、Ａｌ、Ｇａ、Ｓｉ、Ｓｎ、Ｇｅ、Ｐｂ、ＳｂおよびＢｉの１種単独あるいはそれらの２種以上の組み合わせからなる酸化物、ならびにカルコゲナイドが特に好ましい。好ましい非晶質酸化物及びカルコゲナイドの具体例としては、例えば、Ｇａ２Ｏ３、ＳｉＯ、ＧｅＯ、ＳｎＯ、ＳｎＯ２、ＰｂＯ、ＰｂＯ２、Ｐｂ２Ｏ３、Ｐｂ２Ｏ４、Ｐｂ３Ｏ４、Ｓｂ２Ｏ３、Ｓｂ２Ｏ４、Ｓｂ２Ｏ８Ｂｉ２Ｏ３、Ｓｂ２Ｏ８Ｓｉ２Ｏ３、Ｂｉ２Ｏ４、ＳｎＳｉＯ３、ＧｅＳ、ＳｎＳ、ＳｎＳ２、ＰｂＳ、ＰｂＳ２、Ｓｂ２Ｓ３、Ｓｂ２Ｓ５およびＳｎＳｉＳ３が好ましく挙げられる。また、これらは、酸化リチウムとの複合酸化物、例えば、Ｌｉ２ＳｎＯ２であってもよい。 Among the compound group consisting of the amorphous oxide and the chalcogenide, the amorphous oxide of the metalloid element and the chalcogenide are more preferable, and elements of Groups 13 (IIIB) to 15 (VB) of the periodic table, Al , Ga, Si, Sn, Ge, Pb, Sb and Bi are used alone or in combination of two or more thereof, and chalcogenides are particularly preferable. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga 2 O 3 , SiO, GeO, SnO, SnO 2 , PbO, PbO 2 , Pb 2 O 3 , Pb 2 O 4 , Pb 3 O 4 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 8 Bi 2 O 3 , Sb 2 O 8 Si 2 O 3 , Bi 2 O 4 , SnSiO 3 , GeS, SnS, SnS 2 , PbS, PbS 2 , Sb 2 S 3 , Sb 2 S 5 and SnSiS 3 are preferred. Moreover, these may be a complex oxide with lithium oxide, for example, Li 2 SnO 2 .
　負極活物質はチタン原子を含有することも好ましい。より具体的にはＬｉ４Ｔｉ５Ｏ１２（チタン酸リチウム［ＬＴＯ］）がリチウムイオンの吸蔵放出時の体積変動が小さいことから急速充放電特性に優れ、電極の劣化が抑制されリチウムイオン二次電池の寿命向上が可能となる点で好ましい。 It is also preferable that the negative electrode active material contains a titanium atom. More specifically, Li 4 Ti 5 O 12 (lithium titanate [LTO]) is excellent in rapid charge / discharge characteristics due to small volume fluctuations during the insertion and release of lithium ions, and the deterioration of the electrodes is suppressed, and the lithium ion secondary This is preferable in that the battery life can be improved.
　本発明においては、Ｓｉ系の負極を適用することもまた好ましい。一般的にＳｉ負極は、炭素負極（黒鉛およびアセチレンブラックなど）に比べて、より多くのＬｉイオンを吸蔵できる。すなわち、単位質量あたりのＬｉイオンの吸蔵量が増加する。そのため、電池容量を大きくすることができる。その結果、バッテリー駆動時間を長くすることができるという利点がある。 In the present invention, it is also preferable to apply a Si-based negative electrode. In general, a Si negative electrode can occlude more Li ions than a carbon negative electrode (such as graphite and acetylene black). That is, the amount of occlusion of Li ions per unit mass increases. Therefore, the battery capacity can be increased. As a result, there is an advantage that the battery driving time can be extended.
　負極活物質の形状は特に制限されないが粒子状が好ましい。負極活物質の粒子径（体積平均粒子径）は、０．１～６０μｍが好ましい。所定の粒子径にするには、通常の粉砕機や分級機が用いられる。例えば、乳鉢、ボールミル、サンドミル、振動ボールミル、衛星ボールミル、遊星ボールミルおよび旋回気流型ジェットミルや篩などが好適に用いられる。粉砕時には水、あるいはメタノール等の有機溶媒を共存させた湿式粉砕も必要に応じて行うことができる。所望の粒子径とするためには分級を行うことが好ましい。分級方法としては特に限定はなく、篩、風力分級機などを必要に応じて用いることができる。分級は乾式および湿式ともに用いることができる。負極活物質粒子の平均粒子径は、前述の正極活物質の体積平均粒子径の測定方法と同様の方法により測定することができる。 The shape of the negative electrode active material is not particularly limited, but is preferably particulate. The particle diameter (volume average particle diameter) of the negative electrode active material is preferably 0.1 to 60 μm. In order to obtain a predetermined particle size, a normal pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill, and a sieve are preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle diameter, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet. The average particle diameter of the negative electrode active material particles can be measured by the same method as the above-described method for measuring the volume average particle diameter of the positive electrode active material.
　上記焼成法により得られた化合物の化学式は、測定方法として誘導結合プラズマ（ＩＣＰ）発光分光分析法、簡便法として、焼成前後の粉体の質量差から算出できる。 The chemical formula of the compound obtained by the above firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method, and from a mass difference between powders before and after firing as a simple method.
　上記負極活物質は、１種を単独で用いても、２種以上を組み合わせて用いてもよい。
　負極活物質層を形成する場合、負極活物質層の単位面積（ｃｍ２）当たりの負極活物質の質量（ｍｇ）（目付量）は特に限定されるものではない。設計された電池容量に応じて、適宜に決めることができる。 The said negative electrode active material may be used individually by 1 type, or may be used in combination of 2 or more type.
When forming the negative electrode active material layer, the mass (mg) (weight per unit area) of the negative electrode active material per unit area (cm 2 ) of the negative electrode active material layer is not particularly limited. This can be determined as appropriate according to the designed battery capacity.
　負極活物質の、固体電解質組成物中における含有量は、特に限定されず、固形分１００質量％において、１０～８０質量％であることが好ましく、２０～８０質量％がより好ましい。 The content of the negative electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 80% by mass, and more preferably 20 to 80% by mass with a solid content of 100% by mass.
　正極活物質または負極活物質を含む電極表面は硫黄またはリンで表面処理されていてもよい。また、正極活物質または負極活物質の粒子表面は、上記表面被覆の前後において活性光線または活性気体（プラズマ等）により表面処理を施されていても良い。 The electrode surface containing the positive electrode active material or the negative electrode active material may be surface-treated with sulfur or phosphorus. The particle surface of the positive electrode active material or the negative electrode active material may be subjected to surface treatment with actinic rays or an active gas (plasma or the like) before and after the surface coating.
　本発明の全固体二次電池において、固体電解質層、正極活物質層及び負極活物質層には、リチウム塩、導電助剤、バインダー（上記充填材領域に含まれ得る有機バインダーが好ましい）、分散剤等が含まれていることも好ましい。 In the all solid state secondary battery of the present invention, the solid electrolyte layer, the positive electrode active material layer, and the negative electrode active material layer include a lithium salt, a conductive additive, a binder (an organic binder that can be included in the filler region is preferable), a dispersion It is also preferable that an agent or the like is included.
〔集電体（金属箔）〕
　正極集電体５及び負極集電体１は、電子伝導体が好ましい。
　本発明において、正極集電体及び負極集電体のいずれか、又は、両方を合わせて、単に、集電体と称することがある。
　正極集電体を形成する材料としては、アルミニウム、アルミニウム合金、ステンレス鋼、ニッケルおよびチタンなどの他に、アルミニウムまたはステンレス鋼の表面にカーボン、ニッケル、チタンあるいは銀を処理させたもの（薄膜を形成したもの）が好ましく、その中でも、アルミニウムおよびアルミニウム合金がより好ましい。
　負極集電体を形成する材料としては、アルミニウム、銅、銅合金、ステンレス鋼、ニッケルおよびチタンなどの他に、アルミニウム、銅、銅合金またはステンレス鋼の表面にカーボン、ニッケル、チタンあるいは銀を処理させたものが好ましく、アルミニウム、銅、銅合金およびステンレス鋼がより好ましい。 [Current collector (metal foil)]
The positive electrode current collector 5 and the negative electrode current collector 1 are preferably electronic conductors.
In the present invention, either or both of the positive electrode current collector and the negative electrode current collector may be simply referred to as a current collector.
Materials for forming the positive electrode current collector include aluminum, aluminum alloy, stainless steel, nickel and titanium, as well as the surface of aluminum or stainless steel treated with carbon, nickel, titanium or silver (formation of a thin film) Among them, aluminum and aluminum alloys are more preferable.
In addition to aluminum, copper, copper alloy, stainless steel, nickel and titanium, etc., the material for forming the negative electrode current collector is treated with carbon, nickel, titanium or silver on the surface of aluminum, copper, copper alloy or stainless steel. What was made to do is preferable, and aluminum, copper, a copper alloy, and stainless steel are more preferable.
　集電体の形状は、通常フィルムシート状のものが使用されるが、ネット、パンチされたもの、ラス体、多孔質体、発泡体、繊維群の成形体なども用いることができる。
　集電体の厚みは、特に限定されないが、１～５００μｍが好ましい。また、集電体表面は、表面処理により凹凸を付けることも好ましい。 The current collector is usually in the form of a film sheet, but a net, a punched one, a lath, a porous body, a foam, a fiber group molded body, or the like can also be used.
The thickness of the current collector is not particularly limited, but is preferably 1 to 500 μm. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.
　本発明において、負極集電体、負極活物質層、固体電解質層、正極活物質層及び正極集電体の各層の間又はその外側には、機能性の層や部材等を適宜介在ないし配設してもよい。また、各層は単層で構成されていても、複層で構成されていてもよい。 In the present invention, a functional layer, a member, or the like is appropriately interposed or disposed between or outside each of the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector. May be. Each layer may be composed of a single layer or a plurality of layers.
＜全固体二次電池の製造＞
　本発明において、全固体二次電池は、固体電解質層を本発明で規定する形態とすること以外は、常法により製造することができる。本発明の全固体二次電池の製造方法の一例を以下に示すが、本発明の全固体二次電池の製造方法はこれらの形態に限定されるものではない。 <Manufacture of all-solid-state secondary batteries>
In the present invention, the all-solid-state secondary battery can be manufactured by a conventional method except that the solid electrolyte layer is in the form defined by the present invention. Although an example of the manufacturing method of the all-solid-state secondary battery of this invention is shown below, the manufacturing method of the all-solid-state secondary battery of this invention is not limited to these forms.
　基材（例えば、集電体となる金属箔）上に、正極活物質層を構成する成分を含む組成物（正極用組成物）を塗布して正極活物質層を形成し、全固体二次電池用正極シートを作製する。次いで、この正極活物質層の上に、少なくとも上記無機固体電解質材料と上記電子絶縁性材料とを含有する組成物を塗布して層を形成する。次いでこの層の上に負極集電体を重ねる。次いでこの積層体を、電子絶縁性材料が熱溶融する温度（この温度は好ましくは２００℃以下である）まで加熱し、電子絶縁性材料の溶融物を毛細管現象により無機固体電解質材料間の隙間に浸透させる。この毛細管現象により、固体電解質粒子の表層に存在する電子絶縁性材料が層内部の空隙へと移動するため、固体電解質層から正極活物質層への充填材の過剰な染み出しを防ぐことができる。
　その後、冷却して充填材を固化することにより、無機固体電解質材料間の空隙の少なくとも一部が塞がれた固体電解質層を形成することができる。
　こうして、正極活物質層と負極集電体との間に固体電解質層が挟まれた構造の全固体二次電池を得ることができる。必要によりこれを筐体に封入して所望の全固体二次電池とすることができる。また、固体電解質層の上に、負極活物質層と負極集電体と順次重ねることにより、正極活物質層と負極活物質層との間に固体電解質層が挟まれた構造の全固体二次電池を得ることもできる。
　また、各層の形成方法を逆にして、負極集電体上に、負極活物質層、固体電解質層及び正極活物質層を形成し、正極集電体を重ねて、全固体二次電池を製造することもできる。また、基材／負極活物質層からなる２層構造の積層体と、基材／正極活物質層／固体電解質層からなる３層構造の積層体とを調製し、これらを重ねあわせて本発明の全固体二次電池を得ることもできる。また基材／正極活物質層からなる２層構造の積層体と、基材／負極活物質層／固体電解質層からなる３層構造の積層体とを調製し、これらを重ねあわせて本発明の全固体二次電池を得ることもできる。 A composition (a composition for positive electrode) containing a component constituting the positive electrode active material layer is applied onto a base material (for example, a metal foil serving as a current collector) to form a positive electrode active material layer, and an all-solid secondary A positive electrode sheet for a battery is prepared. Next, a layer containing at least the inorganic solid electrolyte material and the electronic insulating material is applied onto the positive electrode active material layer to form a layer. Next, a negative electrode current collector is overlaid on this layer. Next, this laminate is heated to a temperature at which the electronic insulating material is thermally melted (this temperature is preferably 200 ° C. or less), and the melt of the electronic insulating material is put into gaps between the inorganic solid electrolyte materials by capillary action. Infiltrate. Due to this capillary phenomenon, the electronic insulating material present on the surface layer of the solid electrolyte particles moves to the voids inside the layer, so that excessive exudation of the filler from the solid electrolyte layer to the positive electrode active material layer can be prevented. .
Thereafter, by cooling and solidifying the filler, it is possible to form a solid electrolyte layer in which at least part of the voids between the inorganic solid electrolyte materials are closed.
Thus, an all-solid secondary battery having a structure in which the solid electrolyte layer is sandwiched between the positive electrode active material layer and the negative electrode current collector can be obtained. If necessary, this can be enclosed in a housing to obtain a desired all-solid secondary battery. Moreover, an all-solid secondary having a structure in which a solid electrolyte layer is sandwiched between a positive electrode active material layer and a negative electrode active material layer by sequentially stacking a negative electrode active material layer and a negative electrode current collector on the solid electrolyte layer. A battery can also be obtained.
Moreover, the formation method of each layer is reversed, and a negative electrode active material layer, a solid electrolyte layer, and a positive electrode active material layer are formed on the negative electrode current collector, and the positive electrode current collector is stacked to manufacture an all-solid secondary battery. You can also In addition, a laminate having a two-layer structure composed of a substrate / negative electrode active material layer and a laminate having a three-layer structure composed of a substrate / positive electrode active material layer / solid electrolyte layer are prepared, and these are stacked to form the present invention. The all-solid-state secondary battery can be obtained. In addition, a laminate having a two-layer structure composed of a substrate / positive electrode active material layer and a laminate having a three-layer structure composed of a substrate / negative electrode active material layer / solid electrolyte layer were prepared, and these were superposed. An all-solid secondary battery can also be obtained.
　固体電解質層の形成において上記電子絶縁性材料を溶融させるための加熱は、上記無機固体電解質材料と上記電子絶縁性材料とを含有する組成物を用いて層を形成した後であれば、全固体二次電池の製造工程のどの段階で加熱してもよい。また、層形成自体（塗布工程自体）を上記電子絶縁性材料の溶融温以上の温度で行うこともでき、この場合は電子絶縁性材料を溶融させるための加熱工程を別途設ける必要はない。
　また、少なくとも無機固体電解質材料を塗布して形成した層に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却して固体電解質層を形成することもできる。 If the heating for melting the electronic insulating material in the formation of the solid electrolyte layer is after forming the layer using the composition containing the inorganic solid electrolyte material and the electronic insulating material, Heating may be performed at any stage in the manufacturing process of the secondary battery. In addition, the layer formation itself (application process itself) can be performed at a temperature equal to or higher than the melting temperature of the electronic insulating material. In this case, it is not necessary to separately provide a heating step for melting the electronic insulating material.
Further, at least a layer formed by applying an inorganic solid electrolyte material can be impregnated with sulfur in a molten state and / or modified sulfur, and then cooled to form a solid electrolyte layer.
　すなわち、本発明の全固体二次電池の製造方法の好ましい実施形態では、無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した層を加熱し、固体電解質層中の硫黄及び／又は改質硫黄を熱溶融させ、次いで冷却して固体電解質層を形成することを含むものである。本発明において電子絶縁性材料を溶融するために「層を加熱する」形態は、上記電子絶縁性材料を含む層を、この電子絶縁性材料の溶融温度以上の温度に曝すことを意味する。したがって、充填材の溶融温度以上の温度で製膜を行う場合、製膜後、さらに加熱する必要はないのであるが、本発明においては、製膜自体を溶融温度以上の高温で行い、その後に別途加熱処理を行わない形態も、「層を加熱する」形態に含むものとする。このことは、後述する本発明の固体電解質膜の製造においても同様である。 That is, in a preferred embodiment of the method for producing an all solid state secondary battery of the present invention, a layer formed using an inorganic solid electrolyte composition containing an inorganic solid electrolyte material and sulfur and / or modified sulfur is heated. The method includes thermally melting sulfur and / or modified sulfur in the solid electrolyte layer and then cooling to form a solid electrolyte layer. In the present invention, the form of “heating the layer” in order to melt the electronic insulating material means that the layer containing the electronic insulating material is exposed to a temperature equal to or higher than the melting temperature of the electronic insulating material. Therefore, when film formation is performed at a temperature equal to or higher than the melting temperature of the filler, it is not necessary to further heat after film formation.In the present invention, film formation itself is performed at a high temperature equal to or higher than the melting temperature. A form in which heat treatment is not performed separately is also included in the form of “heating the layer”. The same applies to the production of the solid electrolyte membrane of the present invention described later.
　また、本発明の全固体二次電池の製造方法の別の好ましい実施形態は、無機固体電解質材料を用いて形成した層中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却して固体電解質層を形成することを含むものである。 In another preferred embodiment of the method for producing an all-solid-state secondary battery of the present invention, a layer formed using an inorganic solid electrolyte material is impregnated with heat-melted sulfur and / or modified sulfur, Then, it is cooled to form a solid electrolyte layer.
（各層の形成方法）
　本発明の全固体二次電池の製造において、各層の形成方法は特に限定されず、適宜に選択できる。例えば、塗布（好ましくは湿式塗布）、スプレー塗布、スピンコート塗布、ディップコート、スリット塗布、ストライプ塗布およびバーコート塗布が挙げられる。
　各層形成用の塗布液を塗布した後に乾燥処理を施してもよいし、重層塗布した後に乾燥処理をしてもよい。乾燥温度は特に限定されない。下限は３０℃以上が好ましく、６０℃以上がより好ましく、８０℃以上がさらに好ましい。上限は、３００℃以下が好ましく、２５０℃以下がより好ましく、２００℃以下がさらに好ましい。このような温度範囲で加熱することで、（Ｃ）分散媒を除去し、固体状態にすることができる。また、温度を高くしすぎず、全固体二次電池の各部材を損傷せずに済むため好ましい。これにより、全固体二次電池において、優れた総合性能を示し、かつ良好な結着性を得ることができる。 (Method for forming each layer)
In the production of the all solid state secondary battery of the present invention, the method for forming each layer is not particularly limited and can be appropriately selected. Examples thereof include coating (preferably wet coating), spray coating, spin coating coating, dip coating, slit coating, stripe coating, and bar coating coating.
After applying the coating liquid for forming each layer, the drying treatment may be performed, or after the multilayer coating, the drying treatment may be performed. The drying temperature is not particularly limited. The lower limit is preferably 30 ° C or higher, more preferably 60 ° C or higher, and still more preferably 80 ° C or higher. The upper limit is preferably 300 ° C. or lower, more preferably 250 ° C. or lower, and further preferably 200 ° C. or lower. By heating in such a temperature range, (C) a dispersion medium can be removed and it can be set as a solid state. Moreover, it is preferable because the temperature is not excessively raised and each member of the all-solid-state secondary battery is not damaged. Thereby, in the all-solid-state secondary battery, excellent overall performance can be exhibited and good binding properties can be obtained.
　形成した固体電解質層、又は作製した全固体二次電池は、加圧することが好ましい。加圧方法としては油圧シリンダープレス機等が挙げられる。加圧力としては、特に限定されず、一般的には５０～１５００ＭＰａの範囲であることが好ましい。
　また、塗布した固体電解質組成物は、加圧と同時に加熱することが好ましい。加熱温度としては、特に限定されず、一般的には３０～３００℃の範囲である。無機固体電解質のガラス転移温度よりも高い温度でプレスすることもできる。
　加圧は塗布溶媒又は分散媒をあらかじめ乾燥させた状態で行ってもよいし、溶媒又は分散媒が残存している状態で行ってもよい。 The formed solid electrolyte layer or the produced all solid state secondary battery is preferably pressurized. An example of the pressurizing method is a hydraulic cylinder press. The applied pressure is not particularly limited and is generally preferably in the range of 50 to 1500 MPa.
Moreover, it is preferable to heat the applied solid electrolyte composition simultaneously with pressurization. The heating temperature is not particularly limited, and is generally in the range of 30 to 300 ° C. It is also possible to press at a temperature higher than the glass transition temperature of the inorganic solid electrolyte.
The pressurization may be performed in a state where the coating solvent or the dispersion medium is previously dried, or may be performed in a state where the solvent or the dispersion medium remains.
　加圧中の雰囲気としては、特に限定されず、大気下、乾燥空気下（露点－２０℃以下）および不活性ガス中（例えばアルゴンガス中、ヘリウムガス中、窒素ガス中）などいずれでもよい。
　プレス時間は短時間（例えば数時間以内）で高い圧力をかけてもよいし、長時間（１日以上）かけて中程度の圧力をかけてもよい。全固体二次電池用シート以外、例えば全固体二次電池の場合には、中程度の圧力をかけ続けるために、全固体二次電池の拘束具（ネジ締め圧等）を用いることもできる。
　プレス圧はシート面等の被圧部に対して均一であっても異なる圧であってもよい。
　プレス圧は被圧部の面積や膜厚に応じて変化させることができる。また同一部位を段階的に異なる圧力で変えることもできる。
　プレス面は平滑であっても粗面化されていてもよい。 The atmosphere during pressurization is not particularly limited, and may be any of the following: air, dry air (dew point -20 ° C. or lower), and inert gas (for example, argon gas, helium gas, nitrogen gas).
The pressing time may be a high pressure in a short time (for example, within several hours), or a medium pressure may be applied for a long time (1 day or more). In the case of an all-solid-state secondary battery other than the all-solid-state secondary battery sheet, for example, a restraining tool (screw tightening pressure or the like) of the all-solid-state secondary battery can be used in order to keep applying moderate pressure.
The pressing pressure may be uniform or different with respect to the pressed part such as the sheet surface.
The pressing pressure can be changed according to the area and film thickness of the pressed part. Also, the same part can be changed stepwise with different pressures.
The press surface may be smooth or roughened.
　また、電池をシート状に形成し、この電池シートを軸心の外周にロール状に巻いた状態とした円筒型とし、この円筒型電池の最外層から軸心方向に圧力をかける形態とすることもできる。 In addition, the battery is formed into a sheet shape, and the battery sheet is rolled into a roll around the outer periphery of the shaft, and pressure is applied in the axial direction from the outermost layer of the cylindrical battery. You can also.
（初期化）
　上記のようにして製造した全固体二次電池は、製造後又は使用前に初期化を行うことが好ましい。初期化の方法は特に限定されず、例えば、プレス圧を高めた状態で初充放電を行い、その後、全固体二次電池の一般使用圧力になるまで圧力を開放することにより行うことができる。 (Initialization)
The all solid state secondary battery manufactured as described above is preferably initialized after manufacture or before use. The initialization method is not particularly limited. For example, the initial charge / discharge can be performed in a state where the press pressure is increased, and then the pressure can be released until the general use pressure of the all-solid secondary battery is reached.
＜全固体二次電池の用途＞
　本発明の全固体二次電池は種々の用途に適用することができる。適用態様には特に限定はないが、例えば、電子機器に搭載する場合、ノートパソコン、ペン入力パソコン、モバイルパソコン、電子ブックプレーヤー、携帯電話、コードレスフォン子機、ページャー、ハンディーターミナル、携帯ファックス、携帯コピー、携帯プリンター、ヘッドフォンステレオ、ビデオムービー、液晶テレビ、ハンディークリーナー、ポータブルＣＤ、ミニディスク、電気シェーバー、トランシーバー、電子手帳、電卓、メモリーカード、携帯テープレコーダー、ラジオ、バックアップ電源、メモリーカードなどが挙げられる。その他民生用として、自動車、電動車両、モーター、照明器具、玩具、ゲーム機器、ロードコンディショナー、時計、ストロボ、カメラ、医療機器（ペースメーカー、補聴器、肩もみ機など）などが挙げられる。更に、各種軍需用、宇宙用として用いることができる。また、太陽電池と組み合わせることもできる。 <Uses of all-solid-state secondary batteries>
The all solid state secondary battery of the present invention can be applied to various uses. Although there is no particular limitation on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax machine, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, walkie-talkie, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, etc. It is done. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.
　なかでも、高容量かつ高レート放電特性が要求されるアプリケーションに適用することが好ましい。例えば、今後大容量化が予想される蓄電設備等においては高い安全性が必須となりさらに電池性能の両立が要求される。また、電気自動車などは高容量の二次電池を搭載し、家庭で日々充電が行われる用途が想定される。本発明によれば、このような使用形態に好適に対応してその優れた効果を発揮することができる。 Especially, it is preferable to apply to applications that require high capacity and high rate discharge characteristics. For example, in power storage facilities and the like that are expected to increase in capacity in the future, high safety is essential, and further compatibility of battery performance is required. In addition, electric vehicles and the like are equipped with high-capacity secondary batteries and are expected to be charged daily at home. According to the present invention, it is possible to exhibit the excellent effect correspondingly to such a usage pattern.
［全固体二次電池用固体電解質膜］
　本発明の全固体二次電池用固体電解質膜（以下、単に「本発明の電解質膜」という。）は、本発明の全固体二次電池の固体電解質層として好適に用いることができる。すなわち、本発明の電解質膜は、無機固体電解質材料に占有された電解質領域と、無機固体電解質材料の間を埋める充填材領域とを有し、この充填材領域を構成する上記電子絶縁性材料は、固体電解質膜形成時に熱溶融状態として充填されたもの（固体電解質膜形成時における熱溶融履歴を有するもの）である。
　また、本発明の電解質膜は、無機固体電解質材料に占有された電解質領域と、無機固体電解質材料の間を埋める充填材領域とを有し、上記充填材領域のうち一辺が５μｍの正方領域内に収まる充填材領域ＦＲを平面視観察した場合に、ＦＲの面積ＦＡと、ＦＲの外周長さＦＬとの比が、ＦＬ／ＦＡ≧０．８１を満たすことが好ましい。
　本発明の電解質膜の好ましい形態は、上述した本発明の全固体二次電池を構成する固体電解質層の好ましい形態と同じである。 [Solid electrolyte membrane for all-solid-state secondary battery]
The solid electrolyte membrane for an all-solid secondary battery of the present invention (hereinafter simply referred to as “the electrolyte membrane of the present invention”) can be suitably used as the solid electrolyte layer of the all-solid secondary battery of the present invention. That is, the electrolyte membrane of the present invention has an electrolyte region occupied by the inorganic solid electrolyte material and a filler region that fills the space between the inorganic solid electrolyte materials, and the electronic insulating material constituting the filler region is The solid electrolyte membrane is filled as a heat-melted state (having a heat-melting history when the solid electrolyte membrane is formed).
The electrolyte membrane of the present invention has an electrolyte region occupied by the inorganic solid electrolyte material and a filler region that fills the space between the inorganic solid electrolyte materials, and one side of the filler region is within a square region of 5 μm. When the filler region FR that falls within the range is observed in plan view, the ratio of the area FA of the FR to the outer peripheral length FL of the FR preferably satisfies FL / FA ≧ 0.81.
The preferred form of the electrolyte membrane of the present invention is the same as the preferred form of the solid electrolyte layer constituting the all-solid secondary battery of the present invention described above.
＜全固体二次電池用固体電解質膜の製造＞
　本発明の電解質膜は、無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した膜を加熱し、この膜中の硫黄及び／又は改質硫黄を溶融させ、次いで冷却して硫黄及び／又は改質硫黄を固化することにより形成することができる。
　また、本発明の電解質膜は、無機固体電解質材料を用いて形成した膜中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却して硫黄及び／又は改質硫黄を固化することにより形成することができる。
　本発明の電解質膜は、例えば、基材上に形成された状態で得ることができる。また、基材上に電解質膜を形成した後、基材を剥離して電解質膜単体としてもよい。 <Manufacture of solid electrolyte membrane for all solid state secondary battery>
The electrolyte membrane of the present invention heats a membrane formed using an inorganic solid electrolyte composition containing an inorganic solid electrolyte material and sulfur and / or modified sulfur, and the sulfur and / or modified sulfur in the membrane is heated. It can be formed by melting and then cooling to solidify the sulfur and / or modified sulfur.
In the electrolyte membrane of the present invention, the membrane formed using the inorganic solid electrolyte material is impregnated with sulfur and / or modified sulfur in a heat-melted state, and then cooled to obtain sulfur and / or modified sulfur. It can be formed by solidifying.
The electrolyte membrane of this invention can be obtained in the state formed on the base material, for example. Alternatively, after the electrolyte membrane is formed on the substrate, the substrate may be peeled off to form an electrolyte membrane alone.
　本発明を実施例に基づきさらに詳細に説明するが、本発明はこれらの実施形態に限定されるものではない。 The present invention will be described in more detail based on examples, but the present invention is not limited to these embodiments.
［参考例１］　無機固体電解質の合成
　アルゴン雰囲気下（露点－７０℃）のグローブボックス内で、硫化リチウム（Ｌｉ２Ｓ、Ａｌｄｒｉｃｈ社製、純度＞９９．９８％）４．８４ｇ、五硫化二リン（Ｐ２Ｓ５、Ａｌｄｒｉｃｈ社製、純度＞９９％）７．８０ｇをそれぞれ秤量し、メノウ製乳鉢に投入した。Ｌｉ２Ｓ及びＰ２Ｓ５はモル比でＬｉ２Ｓ：Ｐ２Ｓ５＝７５：２５である。メノウ製乳鉢上において、メノウ製乳棒を用いて、５分間混合した。
　ジルコニア製４５ｍＬ容器（フリッチュ社製）に、直径５ｍｍのジルコニアビーズを６６個投入し、上記混合物全量を投入し、アルゴン雰囲気下で容器を完全に密閉した。フリッチュ社製遊星ボールミルＰ－７に容器をセットし、２５℃で、回転数５１０ｒｐｍで２０時間メカニカルミリングを行うことで黄色粉体の硫化物系無機固体電解質（Ｌｉ／Ｐ／Ｓガラス、以下「ＬＰＳ」ともいう。）１２．４ｇを得た。
　得られたＬＰＳの体積平均粒子径を、レーザ回折／散乱式粒度分布測定装置ＬＡ－９２０（商品名、ＨＯＲＩＢＡ社製）を用いて測定した結果、８μｍであった。また、このＬＰＳは、大粒径の粒子の粒子径と、それより小粒径の粒子の粒子径との関係が、[大粒径粒子の粒子径]＞４×[小粒径粒子の粒子径]を満たす関係にある粒子を有するものであった。 Reference Example 1 Synthesis of Inorganic Solid Electrolyte 4.84 g of lithium sulfide (Li 2 S, manufactured by Aldrich, purity> 99.98%) in a glove box under an argon atmosphere (dew point of −70 ° C.), dipentasulfide Each 7.80 g of phosphorus (P 2 S 5 , Aldrich, purity> 99%) was weighed and put into an agate mortar. Li 2 S and P 2 S 5 have a molar ratio of Li 2 S: P 2 S 5 = 75: 25. On an agate mortar, they were mixed for 5 minutes using an agate pestle.
A zirconia 45 mL container (manufactured by Fritsch) was charged with 66 zirconia beads having a diameter of 5 mm, the whole amount of the above mixture was charged, and the container was completely sealed under an argon atmosphere. A container is set on a planetary ball mill P-7 manufactured by Fricht Co. and subjected to mechanical milling at 25 ° C. and a rotation speed of 510 rpm for 20 hours, whereby a yellow powder sulfide-based inorganic solid electrolyte (Li / P / S glass, hereinafter “ Also referred to as “LPS”.) 12.4 g was obtained.
The volume average particle diameter of the obtained LPS was measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA), and as a result, it was 8 μm. Further, in this LPS, the relationship between the particle size of the large particle size and the particle size of the smaller particle size is [particle size of large particle size]> 4 × [particle size of small particle size] Particles having a relationship satisfying the [diameter].
［参考例２］　硫黄と無機固体電解質との混合物の調製
　アルゴン雰囲気下（露点－７０℃）のグローブボックス内で、硫黄（Ｓ、Ａｌｄｒｉｃｈ社製、純度＞９９．９８％）を０．８ｇ、上記ＬＰＳを６．２ｇ、それぞれ秤量し、メノウ製乳鉢に投入した。硫黄及びＬＰＳは質量比でＬＰＳ：Ｓ＝８８：１２、体積比でＬＰＳ：Ｓ＝１００：１１である。メノウ製乳鉢上において、メノウ製乳棒を用いて、１０分間混合した。 [Reference Example 2] Preparation of a mixture of sulfur and an inorganic solid electrolyte In a glove box under an argon atmosphere (dew point -70 ° C), 0.8 g of sulfur (S, manufactured by Aldrich, purity> 99.98%), 6.2 g of the above LPS was weighed and put into an agate mortar. Sulfur and LPS are LPS: S = 88: 12 by mass ratio and LPS: S = 100: 11 by volume ratio. On an agate mortar, they were mixed for 10 minutes using an agate pestle.
［参考例３］　硫黄とアルミナと無機固体電解質との混合物の調製
　アルゴン雰囲気下（露点－７０℃）のグローブボックス内で、硫黄（Ｓ、Ａｌｄｒｉｃｈ社製、純度＞９９．９８％）１．２ｇ、酸化アルミニウムナノ粒子（Ａｌ２Ｏ３、純度＞９９％、粒子サイズ５００ｎｍ、ＥＭジャパン社製）０．６ｇをそれぞれ秤量し、メノウ製乳鉢に投入し、メノウ製乳棒を用いて１０分間混合した。次いで、上記ＬＰＳを８．２ｇ秤量し、上記乳鉢に投入して、メノウ製乳棒を用いて１０分間混合した。ＬＰＳ：アルミナ：硫黄は質量比で８２：６：１２、ＬＰＳ：Ｓは体積比で１００：１１である。 Reference Example 3 Preparation of Mixture of Sulfur, Alumina, and Inorganic Solid Electrolyte 1.2 g of sulfur (S, manufactured by Aldrich, purity> 99.98%) in a glove box under an argon atmosphere (dew point-70 ° C.) , 0.6 g of aluminum oxide nanoparticles (Al 2 O 3 , purity> 99%, particle size 500 nm, manufactured by EM Japan) were weighed, put into an agate mortar, and mixed for 10 minutes using an agate pestle. . Next, 8.2 g of the above LPS was weighed, put into the mortar, and mixed for 10 minutes using an agate pestle. LPS: alumina: sulfur is in a mass ratio of 82: 6: 12, and LPS: S is in a volume ratio of 100: 11.
［製造例］　全固体二次電池の製造
＜全固体二次電池用正極シートの作製＞
　ジルコニア製４５ｍＬ容器（フリッチュ社製）に、直径５ｍｍのジルコニアビーズを１８０個投入し、上記で合成したＬＰＳ２．０ｇと、スチレンブタジエンゴム（商品コード１８２９０７、アルドリッチ社製）０．１ｇと、分散媒としてオクタン２２ｇとを投入した。その後に、この容器をフリッチュ社製遊星ボールミルＰ－７にセットし、温度２５℃で、回転数３００ｒｐｍで２時間攪拌した。その後、正極活物質ＬｉＮｉ０．８５Ｃｏ０．１０Ａｌ０．０５Ｏ２（ニッケルコバルトアルミニウム酸リチウム）７．９ｇを容器に投入し、再びこの容器を遊星ボールミルＰ－７にセットし、温度２５℃、回転数１００ｒｐｍで１５分間混合を続けた。このようにして、正極用組成物を得た。
　次に、集電体となる厚み２０μｍのアルミ箔状に、上記で得られた正極用組成物をベーカー式アプリケーターにより塗布し、８０℃２時間加熱して、正極用組成物を乾燥させた。その後、ヒートプレス機を用いて、所定の密度になるように乾燥させた正極層用組成物を加熱（１２０℃）しながら加圧（６００ＭＰａ、１分）した。このようにして、膜厚１１０μｍの正極活物質層を有する全固体二次電池用正極シートを作製した。 [Production Example] Production of all-solid-state secondary battery <Preparation of cathode sheet for all-solid-state secondary battery>
180 zirconia beads having a diameter of 5 mm are put into a 45 mL container (made by Fritsch) made of zirconia, 2.0 g of LPS synthesized above, 0.1 g of styrene butadiene rubber (product code 182907, made by Aldrich), and a dispersion medium As octane 22 g. Thereafter, the container was set on a planetary ball mill P-7 manufactured by Fritsch, and stirred at a temperature of 25 ° C. and a rotation speed of 300 rpm for 2 hours. Thereafter, 7.9 g of the positive electrode active material LiNi 0.85 Co 0.10 Al 0.05 O 2 (lithium nickel cobalt aluminate) was put into the container, and the container was set again in the planetary ball mill P-7, and the temperature was 25 Mixing was continued for 15 minutes at 100 ° C. and a rotation speed of 100 rpm. In this way, a positive electrode composition was obtained.
Next, the positive electrode composition obtained above was applied to an aluminum foil having a thickness of 20 μm serving as a current collector with a baker type applicator and heated at 80 ° C. for 2 hours to dry the positive electrode composition. Thereafter, using a heat press, the positive electrode layer composition dried to a predetermined density was pressurized (600 MPa, 1 minute) while being heated (120 ° C.). In this way, a positive electrode sheet for an all-solid-state secondary battery having a positive electrode active material layer having a thickness of 110 μm was produced.
＜全固体二次電池の製造＞
　上記参考例２又は３で調製した混合物を、常温トルエン中で分散し固形分２０質量％の塗布液を得た。この塗布液を、常温で上記の正極シート上にバーコート塗布し、１２０℃で乾燥して、膜厚１００μｍの固体電解質層を得た。
　次いで、負極集電体となるＳＵＳ箔を固体電解質層の上に重ね、全固体二次電池用積層体を形成した。
　この積層体に、拘束部材となる拘束板とネジを使い、トルクレンチでネジの締付力を調整し、所定の拘束圧を印加した。
　その後、拘束圧のかかった状態の積層体を、ホットプレート上で１５０℃、１時間の加熱処理に付し、充填材である硫黄を熱溶融させた。
　その後、自然冷却して、拘束圧を８ＭＰａに調整して、実施例１の全固体二次電池とした。 <Manufacture of all-solid-state secondary batteries>
The mixture prepared in Reference Example 2 or 3 was dispersed in room temperature toluene to obtain a coating solution having a solid content of 20% by mass. This coating solution was bar coated on the positive electrode sheet at room temperature and dried at 120 ° C. to obtain a solid electrolyte layer having a thickness of 100 μm.
Subsequently, the SUS foil used as a negative electrode collector was piled up on the solid electrolyte layer, and the laminated body for all-solid-state secondary batteries was formed.
A constraining plate and a screw serving as a constraining member were used for this laminate, and the tightening force of the screw was adjusted with a torque wrench, and a predetermined restraining pressure was applied.
Then, the laminated body in a state where a restraint pressure was applied was subjected to a heat treatment at 150 ° C. for 1 hour on a hot plate, and sulfur as a filler was thermally melted.
Then, it cooled naturally and adjusted the restraint pressure to 8 MPa, and it was set as the all-solid-state secondary battery of Example 1.
　下表に示す条件に変更したこと以外は、実施例１の全固体二次電池と同様にして実施例２、及び比較例１～３の全固体二次電池を得た。 Example 2 and all solid state secondary batteries of Comparative Examples 1 to 3 were obtained in the same manner as the all solid state secondary battery of Example 1, except that the conditions shown in the table below were changed.
［試験例１］　ＦＬ／ＦＡの測定
　上記の固体電解質層を、ＳＥＭ－ＥＤＸ装置を用い、クライオホルダーを用いることで凍結し、冷却した状態で測定を行った。
　まず断面ＳＥＭ像を倍率５０００倍で撮影した。
　次に、同じ断面のＥＤＸ像を元素Ｐと元素Ｓについて取得した。電解質領域と充填材領域（硫黄）の対応づけを、下記のようにＰ（リン）とＳ（硫黄）の有無で実施した。
 
　電解質領域：Ｐ有り、Ｓ有り
　充填材領域：Ｐ無し、Ｓ有り
 
　断面ＳＥＭ画像において、充填材領域として同定された各領域のうち、５μｍの正方領域内（５μｍ×５μｍ）に収まる領域（充填材領域として同定された領域のうち、外周（電解質領域との境界）がすべて、５μｍの正方領域内に収まる領域）を無作為に１０領域選抜し、それらの領域のＦＬ（周長）とＦＡ（面積）を測定した。これらの測定値に基づき決定した各領域のＦＬ／ＦＡの平均（１０領域のＦＬ／ＦＡの平均）を算出した。
　なお、下表中、「ＳＥＭ－ＥＤＸ観察によるＦＲの状態」のカラムにおいて、「空隙」とは、断面ＳＥＭ画像内に観察される、Ｐ無しかつＳ無しの領域を意味する。 [Test Example 1] Measurement of FL / FA The solid electrolyte layer was measured using a SEM-EDX apparatus, frozen using a cryoholder, and cooled.
First, a cross-sectional SEM image was taken at a magnification of 5000 times.
Next, EDX images of the same cross section were acquired for the element P and the element S. The association between the electrolyte region and the filler material region (sulfur) was performed with or without P (phosphorus) and S (sulfur) as described below.

Electrolyte region: with P, with S Filling material region: without P, with S
In the cross-sectional SEM image, among the regions identified as filler regions, the regions that fall within a 5 μm square region (5 μm × 5 μm) (outer regions (boundaries with the electrolyte region) among the regions identified as filler regions) 10 regions were randomly selected (regions that fall within a 5 μm square region), and FL (perimeter) and FA (area) of these regions were measured. The average of FL / FA in each region determined based on these measured values (average of FL / FA in 10 regions) was calculated.
In the table below, in the column “FR state by SEM-EDX observation”, “void” means a region without P and without S, which is observed in the cross-sectional SEM image.
［試験例２］　充放電サイクル特性試験
　上記で作製した各全固体二次電池を用いて、下記条件により充放電を行い、充放電サイクル特性試験を実施した。
（条件）
　３０℃、電流密度０．０９ｍＡ／ｃｍ２（０．０５Ｃに相当）、４．２Ｖ、一定電流条件で充放電 [Test Example 2] Charge / Discharge Cycle Characteristic Test Using each of the all-solid secondary batteries prepared above, charge / discharge was performed under the following conditions, and a charge / discharge cycle characteristic test was performed.
(conditions)
30 ° C, current density 0.09 mA / cm 2 (corresponding to 0.05 C), 4.2 V, charge / discharge under constant current conditions
　内部短絡が生じた場合は充電が完了しないため、５０時間で充電を終了させ、放電させた。内部短絡の有無は、充電時の急激な電圧降下の有無により判断した。
　下記評価基準に基づき、充放電サイクル特性を評価した。
－充放電サイクル特性評価基準－
　Ａ：３サイクル以上でも短絡なし
　Ｂ：２サイクル以上３サイクル未満で短絡
　Ｃ：１サイクル以上２サイクル未満で短絡
　Ｄ：１サイクル未満で短絡
　結果を下表に示す。 Since charging was not completed when an internal short circuit occurred, charging was terminated and discharged in 50 hours. The presence or absence of an internal short circuit was judged by the presence or absence of a sudden voltage drop during charging.
Based on the following evaluation criteria, the charge / discharge cycle characteristics were evaluated.
-Evaluation criteria for charge / discharge cycle characteristics-
A: No short circuit even at 3 cycles or more B: Short circuit at 2 cycles or more and less than 3 cycles C: Short circuit at 1 cycle or more and less than 2 cycles D: Short circuit at less than 1 cycle The results are shown in the table below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表に示される通り、固体電解質層を構成する無機固体電解質の粒子間を、充填材により埋めることにより、短絡を効果的に抑制できることがわかる。 As shown in the above table, it can be seen that short-circuiting can be effectively suppressed by filling the space between the particles of the inorganic solid electrolyte constituting the solid electrolyte layer with a filler.
　本発明をその実施態様とともに説明したが、我々は特に指定しない限り我々の発明を説明のどの細部においても限定しようとするものではなく、添付の請求の範囲に示した発明の精神と範囲に反することなく幅広く解釈されるべきであると考える。 While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.
　本願は、２０１７年３月７日に日本国で特許出願された特願２０１７－０４２６３４に基づく優先権を主張するものであり、これはここに参照してその内容を本明細書の記載の一部として取り込む。 This application claims priority based on Japanese Patent Application No. 2017-042634 filed in Japan on March 7, 2017, which is hereby incorporated herein by reference. Capture as part.
１０　　全固体二次電池
１　　　負極集電体
２　　　負極活物質層
３　　　固体電解質層
４　　　正極活物質層
５　　　正極集電体
６　　　作動部位
２１ａ　固体電解質層
２１ｂ　正極集電体
２１ｃ　正極活物質層
２１ｄ　負極集電体
２１ｅ　負極活物質層
２２　　軸心
２３　　電池カバー DESCRIPTION OF SYMBOLS 10 All-solid-state secondary battery 1 Negative electrode collector 2 Negative electrode active material layer 3 Solid electrolyte layer 4 Positive electrode active material layer 5 Positive electrode collector 6 Actuation site 21a Solid electrolyte layer 21b Positive electrode collector 21c Positive electrode active material layer 21d Negative electrode collector Electrode 21e Negative electrode active material layer 22 Axis 23 Battery cover

Claims (18)

  1. 　固体電解質層が、無機固体電解質材料に占有された電解質領域と、該無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
    　該充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料の熱溶融物を用いて形成されたものである、全固体二次電池。     The solid electrolyte layer has an electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
    The all-solid-state secondary battery, wherein the filler region is formed using a hot melt of an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature region of 200 ° C. or less.
  2. 　固体電解質層が、無機固体電解質材料に占有された電解質領域と、該無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
    　前記充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料を含み、
    　１辺が５μｍの正方領域内に収まる充填材領域ＦＲを平面視観察した場合に、ＦＲの面積ＦＡと、ＦＲの外周長さＦＬとの比が、ＦＬ／ＦＡ≧０．８１を満たす、全固体二次電池。     The solid electrolyte layer has an electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
    The filler region includes an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature region of 200 ° C. or less;
    When the filler region FR that fits in a square region having one side of 5 μm is observed in plan view, the ratio of the area FA of FR to the outer peripheral length FL of FR satisfies FL / FA ≧ 0.81. Solid secondary battery.
  3. 　前記電子絶縁性材料が硫黄及び／又は改質硫黄である、請求項１又は２記載の全固体二次電池。 The all-solid-state secondary battery according to claim 1 or 2, wherein the electronic insulating material is sulfur and / or modified sulfur.
  4. 　前記充填材領域が、アルカリ金属を含む化合物及び／又はアルカリ土類金属を含む化合物を含有する、請求項１～３のいずれか１項記載の全固体二次電池。 The all-solid-state secondary battery according to any one of claims 1 to 3, wherein the filler region contains a compound containing an alkali metal and / or a compound containing an alkaline earth metal.
  5. 　前記充填材領域が有機バインダーを含有する、請求項１～４のいずれか１項記載の全固体二次電池。 The all-solid-state secondary battery according to any one of claims 1 to 4, wherein the filler region contains an organic binder.
  6. 　前記無機固体電解質材料が硫化物系無機固体電解質及び／又は酸化物系無機固体電解質である、請求項１～５のいずれか１項記載の全固体二次電池。 The all-solid-state secondary battery according to any one of claims 1 to 5, wherein the inorganic solid electrolyte material is a sulfide-based inorganic solid electrolyte and / or an oxide-based inorganic solid electrolyte.
  7. 　前記充填材領域が、前記固体電解質層と正極活物質層との界面には存在しない、請求項１～６のいずれか１項記載の全固体二次電池。 The all-solid-state secondary battery according to any one of claims 1 to 6, wherein the filler region does not exist at an interface between the solid electrolyte layer and the positive electrode active material layer.
  8. 　前記無機固体電解質材料が大粒径の粒子と小粒径の粒子とを有し、[大粒径粒子の粒子径]＞４×[小粒径粒子の粒子径]を満たす粒度分布を有する、請求項１～７のいずれか１項記載の全固体二次電池。 The inorganic solid electrolyte material has a large particle size and a small particle size, and has a particle size distribution satisfying [particle size of large particle size]> 4 × [particle size of small particle size]. The all-solid-state secondary battery according to any one of claims 1 to 7.
  9. 　前記固体電解質層中、無機固体電解質材料の含有量１００体積％に対し、前記電子絶縁性材料の含有量が１５体積％未満である、請求項１～８のいずれか１項記載の全固体二次電池。 The all-solid-state secondary battery according to any one of claims 1 to 8, wherein the content of the electronic insulating material is less than 15% by volume with respect to 100% by volume of the inorganic solid electrolyte material in the solid electrolyte layer. Next battery.
  10. 　無機固体電解質材料に占有された電解質領域と、該無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
    　該充填材領域は、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料の熱溶融物を用いて形成されたものである、全固体二次電池用固体電解質膜。     An electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
    The filling material region is a solid electrolyte membrane for an all-solid-state secondary battery, which is formed using a hot melt of an electronic insulating material that is solid at 100 ° C. and thermally melted in a temperature region of 200 ° C. or less.
  11. 　無機固体電解質材料に占有された電解質領域と、該無機固体電解質材料間の空隙を塞ぐ充填材領域とを有し、
    　前記充填材領域が、１００℃において固体でかつ２００℃以下の温度領域で熱溶融する電子絶縁性材料を含み、
    　１辺が５μｍの正方領域内に収まる充填材領域ＦＲを平面視観察した場合に、ＦＲの面積ＦＡと、ＦＲの外周長さＦＬとの比が、ＦＬ／ＦＡ≧０．８１を満たす、全固体二次電池用固体電解質膜。     An electrolyte region occupied by the inorganic solid electrolyte material, and a filler region that closes a gap between the inorganic solid electrolyte material;
    The filler region includes an electronic insulating material that is solid at 100 ° C. and thermally melts in a temperature region of 200 ° C. or less;
    When the filler region FR that fits in a square region having one side of 5 μm is observed in plan view, the ratio of the area FA of FR to the outer peripheral length FL of FR satisfies FL / FA ≧ 0.81. A solid electrolyte membrane for a solid secondary battery.
  12. 　前記電子絶縁性材料が硫黄及び／又は改質硫黄である、請求項１０又は１１記載の全固体二次電池用固体電解質膜。 The solid electrolyte membrane for an all-solid-state secondary battery according to claim 10 or 11, wherein the electronic insulating material is sulfur and / or modified sulfur.
  13. 　前記無機固体電解質材料が硫化物系無機固体電解質及び／又は酸化物系無機固体電解質である、請求項１０～１２のいずれか１項記載の全固体二次電池用固体電解質膜。 The solid electrolyte membrane for an all-solid-state secondary battery according to any one of claims 10 to 12, wherein the inorganic solid electrolyte material is a sulfide-based inorganic solid electrolyte and / or an oxide-based inorganic solid electrolyte.
  14. 　前記無機固体電解質材料が大粒径の粒子と小粒径の粒子とを有し、[大粒径粒子の粒子径]＞４×[小粒径粒子の粒子径]を満たす、請求項１０～１３のいずれか１項記載の全固体二次電池用固体電解質膜。 The inorganic solid electrolyte material has particles having a large particle diameter and particles having a small particle diameter, and satisfies [particle diameter of large particle diameter]> 4 × [particle diameter of small particle diameter]. 14. The solid electrolyte membrane for an all-solid-state secondary battery according to any one of items 13.
  15. 　無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した層を加熱し、該層中の硫黄及び／又は改質硫黄を熱溶融させ、次いで冷却して固体電解質層を形成することを含む、請求項１～９のいずれか１項記載の全固体二次電池の製造方法。 A layer formed using an inorganic solid electrolyte composition containing an inorganic solid electrolyte material and sulfur and / or modified sulfur is heated, and the sulfur and / or modified sulfur in the layer is heated and then cooled. The method for producing an all-solid-state secondary battery according to claim 1, further comprising forming a solid electrolyte layer.
  16. 　無機固体電解質材料を用いて形成した層中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却して固体電解質層を形成することを含む、請求項１～９のいずれか１項記載の全固体二次電池の製造方法。 10. The method according to claim 1, further comprising impregnating a layer formed using the inorganic solid electrolyte material with sulfur in a molten state and / or modified sulfur and then cooling to form a solid electrolyte layer. A method for producing an all-solid-state secondary battery according to claim 1.
  17. 　無機固体電解質材料と硫黄及び／又は改質硫黄とを含有する無機固体電解質組成物を用いて形成した膜を加熱し、該膜中の硫黄及び／又は改質硫黄を熱溶融させ、次いで冷却することを含む、請求項１０～１４のいずれか１項記載の全固体二次電池用固体電解質膜の製造方法。 A film formed using an inorganic solid electrolyte composition containing an inorganic solid electrolyte material and sulfur and / or modified sulfur is heated, and the sulfur and / or modified sulfur in the film is thermally melted and then cooled. The method for producing a solid electrolyte membrane for an all-solid-state secondary battery according to any one of claims 10 to 14, comprising:
  18. 　無機固体電解質材料を用いて形成した膜中に、熱溶融状態にある硫黄及び／又は改質硫黄を含浸させ、次いで冷却することを含む、請求項１０～１４のいずれか１項記載の全固体二次電池用固体電解質膜の製造方法。 The all solid according to any one of claims 10 to 14, comprising impregnating sulfur in a molten state and / or modified sulfur into a film formed using an inorganic solid electrolyte material, and then cooling. A method for producing a solid electrolyte membrane for a secondary battery.
PCT/JP2018/008328 2017-03-07 2018-03-05 All-solid-state secondary battery, production method for same, solid electrolyte film for all-solid-state-electrolyte battery, and production method for same WO2018164051A1 (en)

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