WO2020130069A1 - Electrode layer of solid-state battery and solid-state battery - Google Patents

Electrode layer of solid-state battery and solid-state battery Download PDF

Info

Publication number
WO2020130069A1
WO2020130069A1 PCT/JP2019/049776 JP2019049776W WO2020130069A1 WO 2020130069 A1 WO2020130069 A1 WO 2020130069A1 JP 2019049776 W JP2019049776 W JP 2019049776W WO 2020130069 A1 WO2020130069 A1 WO 2020130069A1
Authority
WO
WIPO (PCT)
Prior art keywords
conductive material
solid electrolyte
less
mass
electrode layer
Prior art date
Application number
PCT/JP2019/049776
Other languages
French (fr)
Japanese (ja)
Inventor
中村　武志
武内　正隆
Original Assignee
昭和電工株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 昭和電工株式会社 filed Critical 昭和電工株式会社
Publication of WO2020130069A1 publication Critical patent/WO2020130069A1/en

Links

Images

Classifications

    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the electrode layer of the present invention has high density and low electric resistance.
  • the solid state battery of the present invention has low internal resistance and high capacity.
  • the electrode layer of the present invention has an excellent balance of macro-conductivity, micro-conductivity and ionic conductivity.
  • Macroconductivity is the degree of conductivity between the current collector and the electrode layer and within the electrode layer. Macro-conductivity is thought to affect the apparent electrical resistance.
  • Microconductivity is the degree of movement of electrons or holes or the degree of uneven distribution of electron paths or hole paths between a solid electrolyte and an active material, between two or more active materials, and the like. Microconductivity is considered to affect energy density and battery capacity.
  • Ionic conductivity is the degree of migration of ions (eg, lithium ions) between the active material and the solid electrolyte and within the compression molding phase of the solid electrolyte powder. Ionic conductivity is considered to affect energy density and battery capacity.
  • the electrode layer of the present invention with respect to the total area of the portion where the active material and the solid electrolyte are in direct contact, in the portion where the granular conductive material is interposed between the active material and the solid electrolyte, the granular conductive material, the granular conductive material,
  • the ratio of the total area of the parts in direct contact with the active material and the total area of the parts in direct contact with the granular conductive material and the solid electrolyte (hereinafter, sometimes referred to as contact area ratio). , 0.85 or more and 4.70 or less, preferably 1.07 or more and 3.70 or less, and more preferably 1.30 or more and 2.0 or less.
  • Direct contact between the granular conductive material and the active material in the area where the granular conductive material is present between the active material and the solid electrolyte, relative to the total area of the area where the active material and the solid electrolyte are in direct contact The ratio of the total area of the contacting parts and the total area of the parts in which the granular conductive material and the solid electrolyte are in direct contact (contact area ratio), was calculated. Note that ⁇ represents the total length of the line segments.
  • LiPS 4 powder 35.7 parts by mass of LiPS 4 powder and 1 part by mass of the granular conductive material (HS-100) were mixed in a mortar for 10 minutes.
  • LiCoO 2 lithium cobalt oxide
  • VGCF fibrous conductive material
  • Comparative Example 6 35 parts by mass of LiPS 4 powder and 5 parts by mass of vapor grown carbon fiber (VGCF (registered trademark)-H) were mixed in a mortar for 10 minutes. 60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 ⁇ m was added thereto and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used.
  • the positive electrode layer had a density ⁇ of 2.76 g/cm 3 and an electric conductivity ⁇ of 0.8560 S/cm ⁇ 1 .
  • the discharge capacity C was 102.9 mAh/g.
  • the impedance Z and the DC internal resistance Rs were over 1000 ⁇ and 1828 ⁇ , respectively.

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

This electrode layer of a solid-state battery includes an active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte, wherein the total amount of the fibrous conductive material and the granular conductive material is 0.5-7.0 parts by mass inclusive with respect to 100 parts by mass of the total amount of the active material, the fibrous conductive material, the granular conductive material, and the solid electrolyte, and the ratio of the sum total of the total area of sections where the granular conductive material and the active material are in direct contact with each other, and the total area of sections where the granular conductive material and the solid electrolyte are in direct contact with each other in a portion where the granular conductive material is interposed between the active material and the solid electrolyte to the total area of sections where the active material and the solid electrolyte are in direct contact with each other is 0.85-4.70 inclusive.

Description

固体電池の電極層、および固体電池Solid battery electrode layer, and solid battery
　本発明は、固体電池（Solid-state battery）の電極層、および固体電池に関する。より詳細に、本発明は、高密度且つ低電気抵抗の電極層、および低内部抵抗且つ高容量の固体電池に関する。 The present invention relates to an electrode layer of a solid-state battery and a solid-state battery. More specifically, the present invention relates to a high density and low electric resistance electrode layer, and a low internal resistance and high capacity solid state battery.
　陽極と陰極との間のイオン伝導を固体電解質が担う固体電池は、イオン伝導のために電解質溶液を用いる電池に比べて安全性に優れているといわれている。そのような固体電池に関して種々の提案がされている。 ㆍSolid batteries, in which the solid electrolyte takes charge of ionic conduction between the anode and the cathode, are said to be superior in safety to batteries that use an electrolyte solution for ionic conduction. Various proposals have been made regarding such solid state batteries.
　例えば、特許文献１は、正極活物質層であって、正極活物質、固体電解質、及び導電助剤を含有し、正極活物質層における固体電解質及び導電助剤の合計含有量が、正極活物質層の合計体積に対して１０体積％～４０体積％であり、かつ電子伝導度／リチウムイオン伝導度比が２～５００である、正極活物質層を開示している。 For example, Patent Document 1 discloses a positive electrode active material layer, which contains a positive electrode active material, a solid electrolyte, and a conductive auxiliary agent, and the total content of the solid electrolyte and the conductive auxiliary agent in the positive electrode active material layer is the positive electrode active material. Disclosed is a positive electrode active material layer having an amount of 10% to 40% by volume based on the total volume of the layer and an electron conductivity/lithium ion conductivity ratio of 2 to 500.
　特許文献２は、正極活物質、固体電解質材料、結着剤、および導電化剤からなり、全固体リチウム二次電池に用いられる正極合剤層であって、前記結着剤がスチレン含有バインダ樹脂であり、前記導電化剤が炭素繊維であることを特徴とする正極合剤層を開示している。 Patent Document 2 is a positive electrode mixture layer used for an all-solid-state lithium secondary battery, which comprises a positive electrode active material, a solid electrolyte material, a binder, and a conductive agent, and the binder is a styrene-containing binder resin. In addition, the positive electrode mixture layer is disclosed in which the conductive agent is carbon fiber.
　特許文献３は、正極活物質と、繊維状炭素とを含み、前記繊維状炭素が前記正極活物質に結合している、正極材料を開示している。 Patent Document 3 discloses a positive electrode material containing a positive electrode active material and fibrous carbon, and the fibrous carbon is bonded to the positive electrode active material.
　特許文献４は、正極活物質と、硫化物固体電解質と、繊維状炭素とを含み、前記繊維状炭素が前記正極活物質の周りに偏在している、正極材料を開示している。 Patent Document 4 discloses a positive electrode material containing a positive electrode active material, a sulfide solid electrolyte, and fibrous carbon, and the fibrous carbon is unevenly distributed around the positive electrode active material.
　特許文献５は、銀イオン導電性固体電解質と、銀バナジウム酸化物電極活物質と、繊維状黒鉛と、球状黒鉛とを含有する電極を有する全固体二次電池を開示している。 Patent Document 5 discloses an all-solid secondary battery having an electrode containing a silver ion conductive solid electrolyte, a silver vanadium oxide electrode active material, fibrous graphite, and spherical graphite.
　特許文献６は、正極層と、固体電解質層と、負極層とを有する全固体リチウム二次電池において、前記正極層に正極活物質の導電助剤として繊維状炭素と球状炭素とが含有されている全固体リチウム二次電池を開示している。 Patent Document 6 discloses an all-solid-state lithium secondary battery having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, wherein the positive electrode layer contains fibrous carbon and spherical carbon as a conduction aid of a positive electrode active material. Discloses an all-solid-state lithium secondary battery.
　特許文献７は、複数の正極活物質粒子と、繊維状導電材と、粒子状導電材と、固体電解質とを含み、前記複数の正極活物質粒子の個数全体を１００％として、前記粒子状導電材を介して前記繊維状導電材と接触している正極活物質粒子の個数が４０％以上である、正極合剤からなる層を有する電極を開示している。 Patent Document 7 includes a plurality of positive electrode active material particles, a fibrous conductive material, a particulate conductive material, and a solid electrolyte, and the total number of the plurality of positive electrode active material particles is 100%, and the particulate conductive material Disclosed is an electrode having a layer made of a positive electrode mixture, in which the number of positive electrode active material particles in contact with the fibrous conductive material through the material is 40% or more.
　特許文献８は、固体電解質、負極および正極を含み、固体電解質は酸化物固体電解質および硫化物固体電解質から選ばれる少なくとも一つであって且つ体積基準累積粒径分布における５０％径が０．１～１０μｍであり、負極は負極活物質３５～４５質量部、導電助剤５～１０質量部および前記固体電解質４５～５５質量部を含み、負極活物質は黒鉛結晶面間隔ｄ002が０．３３６０～０．３３７０ｎｍで且つ体積基準累積粒径分布における５０％径が１～１０μｍの黒鉛粒子を含み、導電助剤は粒子状炭素と繊維状炭素との組み合わせであり得る、全固体リチウムイオン電池を開示している。 Patent Document 8 includes a solid electrolyte, a negative electrode, and a positive electrode, and the solid electrolyte is at least one selected from an oxide solid electrolyte and a sulfide solid electrolyte, and a 50% diameter in a volume-based cumulative particle size distribution is 0.1. The negative electrode contains 35 to 45 parts by mass of the negative electrode active material, 5 to 10 parts by mass of the conductive additive, and 45 to 55 parts by mass of the solid electrolyte, and the negative electrode active material has a graphite crystal plane spacing d 002 of 0.3360. An all-solid-state lithium-ion battery, which contains graphite particles having a particle size of ˜0.3370 nm and a 50% diameter in a volume-based cumulative particle size distribution of 1 to 10 μm, and the conductive additive can be a combination of particulate carbon and fibrous carbon. Disclosure.
　特許文献９は、正極が、７≦２０／（比表面積×平均粒径）≦９を満足するＬｉ－Ｃｏ系複合酸化物粒子からなる活物質と、粒径３μｍ以上の粒状の導電材と、粒径２μｍ以下の粒状の導電材またはアスペクト比が３以上であって繊維径が２μｍ以下の繊維状の導電材とを有するものであり、当該正極と負極の間に、塩と相溶性溶媒とビニリデンフルオライドを主単位とするフッ素ポリマーとを主体成分とする固体電解質層を介在させたことを特徴とするリチウムイオン二次電池を開示している。 Patent Document 9 discloses that a positive electrode has an active material composed of Li—Co-based composite oxide particles satisfying 7≦20/(specific surface area×average particle size)≦9, and a granular conductive material having a particle size of 3 μm or more, A granular conductive material having a particle size of 2 μm or less or a fibrous conductive material having an aspect ratio of 3 or more and a fiber diameter of 2 μm or less, and a salt and a compatible solvent between the positive electrode and the negative electrode. Disclosed is a lithium ion secondary battery in which a solid electrolyte layer containing a fluoropolymer containing vinylidene fluoride as a main unit as a main component is interposed.
特開２０１５－６９７９５号公報JP, 2005-69795, A 特開２０１０－２６２７６４号公報JP, 2010-262764, A ＷＯ２０１４／０７３４７０ＡWO2014/073470A ＷＯ２０１４／０７３４６９ＡWO2014/073469A 特開平４－５６０７７号公報Japanese Patent Laid-Open No. 4-56077 特開２０１６－９６７９号公報JP, 2016-9679, A 特開２０１６－５８２７７号公報JP, 2016-58277, A ＷＯ２０１８／１２３９６７ＡWO2018/123967A 特開２００２－６３９３７号公報JP 2002-63937 A
　本発明の課題は、活物質と繊維状導電材と粒状導電材と固体電解質とを含む新たな電極層および該電極層を有する固体電池を提供することである。 An object of the present invention is to provide a new electrode layer containing an active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte, and a solid battery having the electrode layer.
　本発明は以下の態様を包含する。
〔１〕　活物質と、繊維状導電材と、粒状導電材と、固体電解質とを含み、
　活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して繊維状導電材と粒状導電材との合計量が０．５質量部以上７．０質量部以下であり、
　活物質と固体電解質とが直接に接触している部分の合計面積に対する、粒状導電材が活物質と固体電解質との間に介在している部分における、粒状導電材と活物質とが直接に接触している部分の合計面積および粒状導電材と固体電解質とが直接に接触している部分の合計面積の総和の比が、０．８５以上４．７０以下である、
　固体電池の電極層。 The present invention includes the following aspects.
[1] contains an active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte,
When the total amount of the fibrous conductive material and the granular conductive material is 0.5 parts by mass or more and 7.0 parts by mass or less based on 100 parts by mass of the total amount of the active material, the fibrous conductive material, the granular conductive material, and the solid electrolyte. Yes,
Direct contact between the granular conductive material and the active material in the area where the granular conductive material is present between the active material and the solid electrolyte, relative to the total area of the area where the active material and the solid electrolyte are in direct contact The ratio of the total area of the contacting portion and the total area of the contacting portion of the granular conductive material and the solid electrolyte is 0.85 or more and 4.70 or less,
Electrode layer of solid state battery.
〔２〕　粒状導電材と繊維状導電材との合計量１００質量部に対して粒状導電材の量が１質量部以上５０質量部以下である、〔１〕に記載の電極層。 [2] The electrode layer according to [1], wherein the amount of the granular conductive material is 1 part by mass or more and 50 parts by mass or less based on 100 parts by mass of the total amount of the granular conductive material and the fibrous conductive material.
〔３〕　粒状導電材は、一次粒子の数基準粒度分布における５０％径が５ｎｍ以上１００ｎｍ以下で且つ一次粒子の平均アスペクト比が２未満である炭素質炭素を含有する、〔１〕または〔２〕に記載の電極層。
〔４〕　繊維状導電材は、繊維平均径が１０ｎｍ以上１μｍ以下で且つ繊維平均径に対する繊維平均長さの比が２０以上である炭素質炭素または黒鉛質炭素を含有する、〔１〕～〔３〕のいずれかひとつに記載の電極層。
〔５〕　活物質は、体積基準粒度分布における５０％径が３μｍ以上５０μｍ以下である、〔１〕～〔４〕のいずれかひとつに記載の電極層。
〔６〕　活物質は、一次粒子の数基準粒度分布における５０％径が１００ｎｍ以上３μｍ以下である、〔１〕～〔５〕のいずれかひとつに記載の電極層。
〔７〕　〔１〕～〔６〕のいずれかひとつに記載の電極層と固体電解質層とを有する固体電池。 [3] The granular conductive material contains carbonaceous carbon having a 50% diameter in the number-based particle size distribution of primary particles of 5 nm or more and 100 nm or less and an average aspect ratio of primary particles of less than 2, [1] or [2] ] The electrode layer as described in.
[4] The fibrous conductive material contains carbonaceous carbon or graphitic carbon having an average fiber diameter of 10 nm or more and 1 μm or less and a ratio of the average fiber length to the average fiber diameter of 20 or more, [1] to [1] [3] The electrode layer according to any one of [3].
[5] The electrode layer according to any one of [1] to [4], wherein the active material has a 50% diameter in a volume-based particle size distribution of 3 μm or more and 50 μm or less.
[6] The electrode layer according to any one of [1] to [5], wherein the active material has a 50% diameter in the number-based particle size distribution of primary particles of 100 nm or more and 3 μm or less.
[7] A solid battery having the electrode layer and the solid electrolyte layer according to any one of [1] to [6].
〔８〕　体積基準粒度分布における５０％径が０．１μｍ以上１０μｍ以下である固体電解質の粉末と一次粒子の数基準粒度分布における５０％径が５ｎｍ以上１００ｎｍ以下で且つ一次粒子の平均アスペクト比が２未満である粒状導電材とを混練して混合物Iを得、　混合物Iと一次粒子の数基準粒度分布における５０％径が１００ｎｍ以上３μｍ以下である活物質の粉末とを混練して混合物IIを得、
　混合物IIと繊維平均径が１０ｎｍ以上１μｍ以下で且つ繊維平均径に対する繊維平均長さの比が２０以上である繊維状導電材とを混練して混合物IIIを得、
　次いで混合物IIIを圧縮成形することを有する、
　固体電池の電極層を製造する方法。 [8] Solid electrolyte powder having a 50% diameter in the volume-based particle size distribution of 0.1 μm or more and 10 μm or less and a 50% diameter in the number-based particle size distribution of primary particles of 5 nm or more and 100 nm or less and an average aspect ratio of the primary particles A mixture I of less than 2 is kneaded to obtain a mixture I, and the mixture I is kneaded with a powder of an active material having a 50% diameter in the number-based particle size distribution of primary particles of 100 nm or more and 3 μm or less to obtain a mixture II. Get
Mixture II and a fibrous conductive material having an average fiber diameter of 10 nm or more and 1 μm or less and a ratio of the average fiber length to the average fiber diameter of 20 or more are kneaded to obtain a mixture III,
Then compression molding the mixture III,
A method for manufacturing an electrode layer of a solid-state battery.
〔９〕　固体電解質は、硫化物固体電解質および酸化物固体電解質からなる群から選ばれる少なくとも一つを含有する、〔１〕～〔７〕のいずれかひとつに記載の電極層。
〔１０〕　活物質は、リチウム合金、金属酸化物、グラファイト、ハードカーボン、ソフトカーボン、ケイ素、ケイ素合金、チタン酸リチウムからなる群から選ばれる少なくとも一つを含有する、負極用の、〔１〕～〔７〕のいずれかひとつに記載の電極層。
〔１１〕　活物質は、ＬｉＣｏ酸化物、ＬｉＮｉＣｏ酸化物、ＬｉＮｉＣｏＭｎ酸化物、ＬｉＮｉＭｎ酸化物、ＬｉＭｎ酸化物、ＬｉＭｎ系スピネル、ＬｉＭｎＮｉ酸化物、ＬｉＭｎＡｌ酸化物、ＬｉＭｎＭｇ酸化物、ＬｉＭｎＣｏ酸化物、ＬｉＭｎＦｅ酸化物、ＬｉＭｎＺｎ酸化物、ＬｉＣｒＮｉＭｎ酸化物、ＬｉＣｒＭｎ酸化物、チタン酸リチウム、リン酸金属リチウム、遷移金属酸化物、硫化チタン、グラファイト、ハードカーボン、遷移金属含有リチウム窒化物、酸化ケイ素、ケイ酸リチウム、リチウム金属、リチウム合金、Ｌｉ含有固溶体、およびリチウム貯蔵性金属間化合物からなる群から選ばれる少なくとも一つを含有する、正極用の、〔１〕～〔７〕のいずれかひとつに記載の電極層。
〔１２〕　活物質と、繊維状導電材と、粒状導電材と、固体電解質とを含み、
　活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して繊維状導電材と粒状導電材との合計量が０．５質量部以上５．０質量部未満であり、
　粒状導電材と繊維状導電材との合計量１００質量部に対して粒状導電材の量が１質量部以上５０質量部未満であり、
　固体電解質は、体積基準粒度分布における５０％径が０．１μｍ以上１０μｍ以下であった粉末を活物質、繊維状導電材および粒状導電材のそれぞれの外形に合うように圧縮変形させた形状をなしており、
　活物質と固体電解質とが直接に接触している部分と、粒状導電材が活物質と固体電解質との間に介在している部分と、繊維状導電材が少なくとも２つの活物質の間または固体電解質と活物質との間を橋渡ししている部分とを有する、電極層。 [9] The electrode layer according to any one of [1] to [7], wherein the solid electrolyte contains at least one selected from the group consisting of a sulfide solid electrolyte and an oxide solid electrolyte.
[10] For the negative electrode, the active material contains at least one selected from the group consisting of lithium alloy, metal oxide, graphite, hard carbon, soft carbon, silicon, silicon alloy, and lithium titanate, [1] An electrode layer according to any one of to [7].
[11] The active material is LiCo oxide, LiNiCo oxide, LiNiCoMn oxide, LiNiMn oxide, LiMn oxide, LiMn-based spinel, LiMnNi oxide, LiMnAl oxide, LiMnMg oxide, LiMnCo oxide, LiMnFe oxide. , LiMnZn oxide, LiCrNiMn oxide, LiCrMn oxide, lithium titanate, lithium metal phosphate, transition metal oxide, titanium sulfide, graphite, hard carbon, lithium nitride containing transition metal, silicon oxide, lithium silicate, lithium The electrode layer according to any one of [1] to [7] for a positive electrode, containing at least one selected from the group consisting of a metal, a lithium alloy, a Li-containing solid solution, and a lithium-storing intermetallic compound.
[12] contains an active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte,
When the total amount of the fibrous conductive material and the granular conductive material is 0.5 parts by mass or more and less than 5.0 parts by mass with respect to 100 parts by mass of the total amount of the active material, the fibrous conductive material, the granular conductive material, and the solid electrolyte. Yes,
The amount of the granular conductive material is 1 part by mass or more and less than 50 parts by mass based on 100 parts by mass of the total amount of the granular conductive material and the fibrous conductive material,
The solid electrolyte has a shape obtained by compressing and deforming powder having a 50% diameter in the volume-based particle size distribution of 0.1 μm or more and 10 μm or less so as to fit the outer shapes of the active material, the fibrous conductive material, and the granular conductive material. And
The part where the active material and the solid electrolyte are in direct contact, the part where the granular conductive material is interposed between the active material and the solid electrolyte, and the fibrous conductive material is between at least two active materials or solid. An electrode layer having a portion bridging between the electrolyte and the active material.
　本発明の電極層は、高密度で且つ低電気抵抗である。本発明の固体電池は、低内部抵抗で且つ高容量である。本発明の電極層は、マクロ導電性、ミクロ導電性およびイオン伝導性のバランスに優れる。マクロ導電性は集電体と電極層との間および電極層内の導電の度合いである。マクロ導電性は見掛け上の電気抵抗に影響すると考えられる。ミクロ導電性は固体電解質と活物質との間、２以上の活物質の間などにおける、電子または正孔の移動の度合いまたは電子パスまたは正孔パスの偏在度合いである。ミクロ導電性はエネルギー密度や電池容量に影響すると考えられる。イオン伝導性は、活物質と固体電解質との間および固体電解質粉末の圧縮成形相内におけるイオン（例えば、リチウムイオン）の移動の度合いである。イオン伝導性はエネルギー密度や電池容量に影響すると考えられる。 The electrode layer of the present invention has high density and low electric resistance. The solid state battery of the present invention has low internal resistance and high capacity. The electrode layer of the present invention has an excellent balance of macro-conductivity, micro-conductivity and ionic conductivity. Macroconductivity is the degree of conductivity between the current collector and the electrode layer and within the electrode layer. Macro-conductivity is thought to affect the apparent electrical resistance. Microconductivity is the degree of movement of electrons or holes or the degree of uneven distribution of electron paths or hole paths between a solid electrolyte and an active material, between two or more active materials, and the like. Microconductivity is considered to affect energy density and battery capacity. Ionic conductivity is the degree of migration of ions (eg, lithium ions) between the active material and the solid electrolyte and within the compression molding phase of the solid electrolyte powder. Ionic conductivity is considered to affect energy density and battery capacity.
実施例１のインピーダンス測定データを示す図である。5 is a diagram showing impedance measurement data of Example 1. FIG. 実施例１の直流内部抵抗測定データを示す図である。FIG. 3 is a diagram showing DC internal resistance measurement data of Example 1.
　本発明の電極層は、活物質と、繊維状導電材と、粒状導電材と、固体電解質とを含む。 The electrode layer of the present invention contains an active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte.
　活物質は、電気を起こす反応に関与する物質、または電子の受け渡しに関与する物質であれば特に限定されない。
　負極用の活物質としては、リチウム合金、金属酸化物、グラファイト、ハードカーボン、ソフトカーボン、ケイ素、ケイ素合金、チタン酸リチウムからなる群から選ばれる少なくとも一つを含有するものを挙げることができる。
　正極用の活物質としては、ＬｉＣｏ酸化物、ＬｉＮｉＣｏ酸化物、ＬｉＮｉＣｏＭｎ酸化物、ＬｉＮｉＭｎ酸化物、ＬｉＭｎ酸化物、ＬｉＭｎ系スピネル、ＬｉＭｎＮｉ酸化物、ＬｉＭｎＡｌ酸化物、ＬｉＭｎＭｇ酸化物、ＬｉＭｎＣｏ酸化物、ＬｉＭｎＦｅ酸化物、ＬｉＭｎＺｎ酸化物、ＬｉＣｒＮｉＭｎ酸化物、ＬｉＣｒＭｎ酸化物、チタン酸リチウム、リン酸金属リチウム、遷移金属酸化物、硫化チタン、グラファイト、ハードカーボン、遷移金属含有リチウム窒化物、酸化ケイ素、ケイ酸リチウム、リチウム金属、リチウム合金、Ｌｉ含有固溶体、およびリチウム貯蔵性金属間化合物からなる群から選ばれる少なくとも一つを含有するものを挙げることができる。 The active material is not particularly limited as long as it is a substance involved in a reaction that causes electricity or a substance involved in transfer of electrons.
Examples of the active material for the negative electrode include those containing at least one selected from the group consisting of lithium alloy, metal oxide, graphite, hard carbon, soft carbon, silicon, silicon alloy, and lithium titanate.
Examples of the active material for the positive electrode include LiCo oxide, LiNiCo oxide, LiNiCoMn oxide, LiNiMn oxide, LiMn oxide, LiMn-based spinel, LiMnNi oxide, LiMnAl oxide, LiMnMg oxide, LiMnCo oxide, and LiMnFe oxide. Products, LiMnZn oxides, LiCrNiMn oxides, LiCrMn oxides, lithium titanates, lithium metal phosphates, transition metal oxides, titanium sulfide, graphite, hard carbon, transition metal-containing lithium nitrides, silicon oxides, lithium silicates, Examples thereof include those containing at least one selected from the group consisting of lithium metal, lithium alloys, Li-containing solid solutions, and lithium-storing intermetallic compounds.
　本発明に用いられる活物質は、好ましくは粒状であり、電極層中において、一次粒子の数基準粒度分布における５０％径が、好ましくは１００ｎｍ以上３μｍ以下、より好ましくは５００ｎｍ以上２μｍ以下である。
　本発明に用いられる活物質は、好ましくは粒状であり、電極層中において、二次粒子を形成していてもよい。本発明に用いられる活物質は、体積基準粒度分布における５０％径が、好ましくは３μｍ以上５０μｍ以下、より好ましくは４μｍ以上２０μｍ以下である。
　また、本発明に用いられる活物質は、短径に対する長径の比、すなわちアスペクト比が、好ましくは３未満、より好ましくは２未満である。 The active material used in the present invention is preferably granular, and the 50% diameter in the number-based particle size distribution of primary particles in the electrode layer is preferably 100 nm or more and 3 μm or less, more preferably 500 nm or more and 2 μm or less.
The active material used in the present invention is preferably granular, and may form secondary particles in the electrode layer. The active material used in the present invention has a 50% diameter in a volume-based particle size distribution of preferably 3 μm or more and 50 μm or less, more preferably 4 μm or more and 20 μm or less.
The active material used in the present invention has a ratio of major axis to minor axis, that is, an aspect ratio, of preferably less than 3, more preferably less than 2.
　電極層に含有する活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して、電極層に含有する活物質の量は、好ましくは４０質量部以上、より好ましくは４５質量部以上、さらに好ましくは５０質量部以上である。電極層に含有する活物質の量は、電極層に含有する活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して、上限が、好ましくは９０質量部、より好ましいは８０質量部、さらに好ましくは７０質量部である。電極層に含有する活物質の量は、電極層における電子伝導性およびイオン電導性ならびに固体電池の放電容量を所望の状態とするために適宜設定できる。 The amount of the active material contained in the electrode layer is preferably 40 parts by mass or more, more preferably 100 parts by mass with respect to the total amount of the active material, the fibrous conductive material, the granular conductive material and the solid electrolyte contained in the electrode layer. Is 45 parts by mass or more, more preferably 50 parts by mass or more. The amount of the active material contained in the electrode layer is preferably 90 parts by mass, with respect to the total amount of 100 parts by mass of the active material, the fibrous conductive material, the granular conductive material and the solid electrolyte contained in the electrode layer. It is more preferably 80 parts by mass, further preferably 70 parts by mass. The amount of the active material contained in the electrode layer can be appropriately set in order to bring the electron conductivity and ionic conductivity in the electrode layer and the discharge capacity of the solid state battery into a desired state.
　繊維状導電材は、電極層に導電性を付与できる繊維状物質であればとくに限定されない。例えば、カーボンナノチューブ、カーボンナノファイバ、気相成長炭素繊維（例えば、ＶＧＣＦ（登録商標）など）などの繊維状炭素、繊維状金属、酸化スズ系繊維などの繊維状導電性酸化物、チタン酸カリウムベース繊維などの導電層被覆繊維などを挙げることができる。これらのうち、カーボンナノチューブ、カーボンナノファイバ、気相成長炭素繊維（例えば、ＶＧＣＦ（登録商標）など）などの繊維状炭素が好ましく、炭素質炭素または黒鉛質炭素を含有する繊維状炭素がより好ましく、繊維状の炭素質炭素を含有する繊維状炭素がさらに好ましい。
　なお、炭素質炭素材料は、炭素原子により形成される結晶の発達が低い炭素材料である。炭素質炭素材料は、例えば、炭素前駆体を炭素化することによって製造することができる。黒鉛質炭素材料は、炭素原子により形成される結晶が大きく発達した炭素材料である。黒鉛質炭素材料は、炭素質炭素材料に比べて、滑りやすく、柔らかく、引っ掻き強度が低い炭素材料である。黒鉛質炭素材料は、例えば、炭素前駆体を黒鉛化することによって製造することができる。 The fibrous conductive material is not particularly limited as long as it is a fibrous substance capable of imparting conductivity to the electrode layer. For example, carbon nanotubes, carbon nanofibers, fibrous carbon such as vapor grown carbon fiber (eg, VGCF (registered trademark)), fibrous metal, fibrous conductive oxide such as tin oxide fiber, and potassium titanate. Examples thereof include conductive layer-covered fibers such as base fibers. Of these, carbon nanotubes, carbon nanofibers, fibrous carbon such as vapor grown carbon fibers (for example, VGCF (registered trademark)) and the like are preferable, and fibrous carbon containing carbonaceous carbon or graphitic carbon is more preferable. Further, fibrous carbon containing fibrous carbonaceous carbon is more preferable.
The carbonaceous carbon material is a carbon material in which the growth of crystals formed by carbon atoms is low. The carbonaceous carbon material can be produced, for example, by carbonizing a carbon precursor. The graphitic carbon material is a carbon material in which crystals formed by carbon atoms are greatly developed. The graphitic carbon material is a carbon material that is more slippery, softer, and has a lower scratch strength than the carbonaceous carbon material. The graphitic carbon material can be produced, for example, by graphitizing a carbon precursor.
　本発明に用いられる繊維状導電材は、繊維平均径が、好ましくは１０ｎｍ以上１μｍ以下、より好ましくは２０ｎｍ以上７００ｎｍ以下、さらに好ましくは３０ｎｍ以上５００ｎｍ以下である。また、本発明に用いられる繊維状導電材は、繊維平均径に対する繊維平均長さの比が、好ましくは５以上１５０００以下、より好ましくは１０以上１２５００以下、さらに好ましくは２０以上１００００以下である。なお、繊維平均長さおよび繊維平均径は、走査型電子顕微鏡（ＳＥＭ）像を基に算出した数平均繊維長さ、数平均繊維径である。 The fibrous conductive material used in the present invention has an average fiber diameter of preferably 10 nm or more and 1 μm or less, more preferably 20 nm or more and 700 nm or less, and further preferably 30 nm or more and 500 nm or less. In the fibrous conductive material used in the present invention, the ratio of the average fiber length to the average fiber diameter is preferably 5 or more and 15,000 or less, more preferably 10 or more and 12,500 or less, and further preferably 20 or more and 10000 or less. The fiber average length and fiber average diameter are the number average fiber length and number average fiber diameter calculated based on a scanning electron microscope (SEM) image.
　粒状導電材は、電極層に導電性を付与できる粒状物質であればとくに限定されない。例えば、アセチレンブラック、ケッチェンブラック、チャンネルブラック、ランプブラック、オイルファーネスブラック、サーマルブラックなどの粒状導電性炭素、アルミニウム粉、銅粉、ニッケル粉、チタン粉などの粒状導電性金属、ＩＴＯ、ＡＴＯなどの粒状導電性酸化物などを挙げることができる。これらのうち、粒状導電性炭素粉が好ましく、炭素質炭素を含有する粒状導電性炭素粉がより好ましい。 The granular conductive material is not particularly limited as long as it is a granular substance capable of imparting conductivity to the electrode layer. For example, granular conductive carbon such as acetylene black, Ketjen black, channel black, lamp black, oil furnace black, thermal black, granular conductive metal such as aluminum powder, copper powder, nickel powder, titanium powder, ITO, ATO, etc. Examples thereof include granular conductive oxides. Of these, granular conductive carbon powder is preferable, and granular conductive carbon powder containing carbonaceous carbon is more preferable.
　本発明に用いられる粒状導電材は、一次粒子の数基準粒度分布における５０％径が、好ましくは５ｎｍ以上１００ｎｍ以下、より好ましくは１０ｎｍ以上８０ｎｍ以下、さらに好ましくは１５ｎｍ以上６５ｎｍ以下である。また本発明に用いられる粒状導電材は、一次粒子の平均アスペクト比が、好ましくは２．０未満、より好ましくは１．８未満である。 In the granular conductive material used in the present invention, the 50% diameter in the number-based particle size distribution of primary particles is preferably 5 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, still more preferably 15 nm or more and 65 nm or less. In the granular conductive material used in the present invention, the average aspect ratio of the primary particles is preferably less than 2.0, more preferably less than 1.8.
　電極層に含有する繊維状導電材と粒状導電材との合計量は、電極層に含有する活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して、０．５質量部以上７．０質量部以下、好ましくは１．０質量部以上６．０質量部以下、さらに好ましくは１．５質量部以上５．０質量部以下である。 The total amount of the fibrous conductive material and the granular conductive material contained in the electrode layer is 0 with respect to 100 parts by mass of the total amount of the active material, the fibrous conductive material, the granular conductive material and the solid electrolyte contained in the electrode layer. The amount is 0.5 parts by mass or more and 7.0 parts by mass or less, preferably 1.0 parts by mass or more and 6.0 parts by mass or less, and more preferably 1.5 parts by mass or more and 5.0 parts by mass or less.
　電極層に含有する粒状導電材の量は、電極層に含有する粒状導電材と繊維状導電材との合計量１００質量部に対して、好ましくは１質量部以上５０質量部以下、より好ましくは１０質量部以上４５質量部以下、さらに好ましくは２０質量部以上４０質量部以下である。粒状導電材を５０質量部以下とすることでイオン伝導性を高くすることができる。粒状導電材を１質量部以上とすることで導電性を高くすることができる。 The amount of the granular conductive material contained in the electrode layer is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 100 parts by mass of the total amount of the granular conductive material and the fibrous conductive material contained in the electrode layer. The amount is 10 parts by mass or more and 45 parts by mass or less, more preferably 20 parts by mass or more and 40 parts by mass or less. Ion conductivity can be increased by adjusting the content of the granular conductive material to 50 parts by mass or less. By setting the amount of the granular conductive material to 1 part by mass or more, the conductivity can be increased.
　固体電解質は、硫化物固体電解質および酸化物固体電解質からなる群から選ばれる少なくとも一つを含有するものが好ましく、硫化物固体電解質がより好ましい。 The solid electrolyte preferably contains at least one selected from the group consisting of a sulfide solid electrolyte and an oxide solid electrolyte, more preferably a sulfide solid electrolyte.
　硫化物固体電解質としては、硫化物ガラス、硫化物ガラスセラミックス、Ｔｈｉｏ－ＬＩＳＩＣＯＮ型硫化物などを挙げることができる。より具体的には、例えば、Ｌｉ2Ｓ－Ｐ2Ｓ5、Ｌｉ2Ｓ－Ｐ2Ｓ5－ＬｉＩ、Ｌｉ2Ｓ－Ｐ2Ｓ5－ＬｉＣｌ、Ｌｉ2Ｓ－Ｐ2Ｓ5－ＬｉＢｒ、Ｌｉ2Ｓ－Ｐ2Ｓ5－Ｌｉ2Ｏ、Ｌｉ2Ｓ－Ｐ2Ｓ5－Ｌｉ2Ｏ－ＬｉＩ、Ｌｉ2Ｓ－ＳｉＳ2、Ｌｉ2Ｓ－ＳｉＳ2－ＬｉＩ、Ｌｉ2Ｓ－ＳｉＳ2－ＬｉＢｒ、Ｌｉ2Ｓ－ＳｉＳ2－ＬｉＣｌ、Ｌｉ2Ｓ－ＳｉＳ2－Ｂ2Ｓ3－ＬｉＩ、Ｌｉ2Ｓ－ＳｉＳ2－Ｐ2Ｓ5－ＬｉＩ、Ｌｉ2Ｓ－Ｂ2Ｓ3、Ｌｉ2Ｓ－Ｐ2Ｓ5－ＺmＳn（ただし、ｍ、ｎは正の数。Ｚは、Ｇｅ、Ｚｎ、Ｇａのいずれか。）、Ｌｉ2Ｓ－ＧｅＳ2、Ｌｉ2Ｓ－ＳｉＳ2－Ｌｉ3ＰＯ4、Ｌｉ2Ｓ－ＳｉＳ2－ＬｉxＭＯy（ただし、ｘ、ｙは正の数。Ｍは、Ｐ、Ｓｉ、Ｇｅ、Ｂ、Ａｌ、Ｇａ、Ｉｎのいずれか。）、Ｌｉ10ＧｅＰ2Ｓ12、Ｌｉ3.25Ｇｅ0.25Ｐ0.75Ｓ4、３０Ｌｉ2Ｓ・２６Ｂ2Ｓ3・４４ＬｉＩ、６３Ｌｉ2Ｓ・３６ＳｉＳ2・１Ｌｉ3ＰＯ4、５７Ｌｉ2Ｓ・３８ＳｉＳ2・５Ｌｉ4ＳｉＯ4、７０Ｌｉ2Ｓ・３０Ｐ2Ｓ5、５０ＬｉＳ2・５０ＧｅＳ2、Ｌｉ7Ｐ3Ｓ11、Ｌｉ3.25Ｐ0.95Ｓ4、Ｌｉ3ＰＳ4、Ｌｉ2Ｓ・Ｐ2Ｓ3・Ｐ2Ｓ5等を挙げることができる。また、硫化物固体電解質材料は、非晶質であっても良く、結晶質であっても良く、ガラスセラミックスであっても良い。 Examples of the sulfide solid electrolyte include sulfide glass, sulfide glass ceramics, Thio-LISICON type sulfide, and the like. More specifically, for example, Li 2 S-P 2 S 5 , Li 2 S-P 2 S 5 -LiI, Li 2 S-P 2 S 5 -LiCl, Li 2 S-P 2 S 5 -LiBr, Li 2 S-P 2 S 5 -Li 2 O, Li 2 S-P 2 S 5 -Li 2 O-LiI, Li 2 S-SiS 2 , Li 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 -LiCl, Li 2 S-SiS 2 -B 2 S 3 -LiI, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 S-B 2 S 3, Li 2 S—P 2 S 5 —Z m S n (where m and n are positive numbers; Z is Ge, Zn, or Ga), Li 2 S—GeS 2 , Li 2 S—SiS 2 -Li 3 PO 4 , Li 2 S-SiS 2 -Li x MO y (where x and y are positive numbers, and M is P, Si, Ge, B, Al, Ga or In). Li 10 GeP 2 S 12 , Li 3.25 Ge 0.25 P 0.75 S 4 , 30Li 2 S.26B 2 S 3 .44LiI, 63Li 2 S.36SiS 2 .1Li 3 PO 4 , 57Li 2 S.38SiS 2 .5Li 4 SiO 4 the 70Li 2 S · 30P 2 S 5 , 50LiS 2 · 50GeS 2, Li 7 P 3 S 11, Li 3.25 P 0.95 S 4, Li 3 PS 4, Li 2 S · P 2 S 3 · P 2 S 5 , etc. Can be mentioned. Further, the sulfide solid electrolyte material may be amorphous, crystalline, or glass ceramics.
　酸化物固体電解質としては、ガーネット型複合酸化物、ペロブスカイト型複合酸化物、ＬＩＳＩＣＯＮ型複合酸化物、ＮＡＳＩＣＯＮ型複合酸化物、Ｌｉアルミナ型複合酸化物、ＬＩＰＯＮ、酸化物ガラスなどを挙げることができる。より具体的には、例えば、Ｌａ0.51Ｌｉ0.34ＴｉＯ2.94、Ｌｉ1.3Ａｌ0.3Ｔｉ1.7（ＰＯ4）3、Ｌｉ7Ｌａ3Ｚｒ2Ｏ12、５０Ｌｉ4ＳｉＯ4・５０Ｌｉ3ＢＯ3、Ｌｉ2.9ＰＯ3.3Ｎ0.46、Ｌｉ3.6Ｓｉ0.6Ｐ0.4Ｏ4、Ｌｉ1.07Ａｌ0.69Ｔｉ1.46（ＰＯ4）3、Ｌｉ1.5Ａｌ0.5Ｇｅ1.5（ＰＯ4）3などを挙げることができる。 Examples of the oxide solid electrolyte include garnet-type complex oxide, perovskite-type complex oxide, LISICON-type complex oxide, NASICON-type complex oxide, Li-alumina-type complex oxide, LIPON, and oxide glass. More specifically, for example, La 0.51 Li 0.34 TiO 2.94 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Li 7 La 3 Zr 2 O 12 , 50Li 4 SiO 4 .50Li 3 BO 3 , Li 2.9 PO 3.3. N 0.46, Li 3.6 Si 0.6 P 0.4 O 4, Li 1.07 Al 0.69 Ti 1.46 (PO 4) 3, Li 1.5 Al 0.5 Ge 1.5 (PO 4) and the like 3.
　本発明に用いられる固体電解質は、常温（２５℃）における電気伝導度が、好ましくは１×１０-5Ｓ／ｃｍ以上、より好ましくは１×１０-4Ｓ／ｃｍ以上、さらに好ましくは１×１０-3Ｓ／ｃｍ以上である。 The solid electrolyte used in the present invention has an electric conductivity at room temperature (25° C.) of preferably 1×10 −5 S/cm or more, more preferably 1×10 −4 S/cm or more, and further preferably 1×. It is 10 −3 S/cm or more.
　本発明に用いられる固体電解質は、電極層において、体積基準粒度分布における５０％径が０．１μｍ以上１０μｍ以下であった粉末を活物質、繊維状導電材および粒状導電材のそれぞれの外形に合うように圧縮変形させた形状を成していることが好ましく、さらに該圧縮変形によって固体電解質粉末間の境界が実質的に無い状態を成していることが好ましい。 In the solid electrolyte used in the present invention, in the electrode layer, a powder having a 50% diameter in the volume-based particle size distribution of 0.1 μm or more and 10 μm or less fits the respective outer shapes of the active material, the fibrous conductive material, and the granular conductive material. As described above, the shape is preferably compressed and deformed, and it is preferable that the boundary between solid electrolyte powders is substantially absent due to the compressed deformation.
　電極層にはさらにバインダが含まれていてもよい。バインダとしては、例えば、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、ポリエチレンオキサイド、ポリビニルアセテート、ポリメタクリレート、ポリアクリレート、ポリアクリロニトリル、ポリビニルアルコール、スチレン－ブタジエンラバー、カルボキシメチルセルロース等を挙げることができる。 The electrode layer may further contain a binder. Examples of the binder include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene oxide, polyvinyl acetate, polymethacrylate, polyacrylate, polyacrylonitrile, polyvinyl alcohol, styrene-butadiene rubber, and carboxymethyl cellulose.
　本発明の電極層は、活物質と固体電解質とが直接に接触している部分の合計面積に対する、粒状導電材が活物質と固体電解質との間に介在している部分における、粒状導電材と活物質とが直接に接触している部分の合計面積および粒状導電材と固体電解質とが直接に接触している部分の合計面積の総和の比（以下、接触面積比ということがある。）が、０．８５以上４．７０以下、好ましくは１．０７以上３．７０以下、より好ましくは１．３０以上２．０以下である。 The electrode layer of the present invention, with respect to the total area of the portion where the active material and the solid electrolyte are in direct contact, in the portion where the granular conductive material is interposed between the active material and the solid electrolyte, the granular conductive material, The ratio of the total area of the parts in direct contact with the active material and the total area of the parts in direct contact with the granular conductive material and the solid electrolyte (hereinafter, sometimes referred to as contact area ratio). , 0.85 or more and 4.70 or less, preferably 1.07 or more and 3.70 or less, and more preferably 1.30 or more and 2.0 or less.
　本発明の電極層は、活物質と固体電解質とが直接に接触している部分と、粒状導電材が活物質と固体電解質との間に介在している部分と、繊維状導電材が少なくとも２つの活物質の間または固体電解質と活物質との間を橋渡ししている部分とを有することが好ましい。 The electrode layer of the present invention comprises a portion where the active material and the solid electrolyte are in direct contact with each other, a portion where the granular conductive material is interposed between the active material and the solid electrolyte, and at least two fibrous conductive materials. It is preferable to have a portion bridging between two active materials or a bridge between the solid electrolyte and the active material.
　本発明の固体電池の電極層を製造する方法は、上記のような構造となる方法であれば特に制限されない。本発明の固体電池の電極層を製造するための好ましい方法は、体積基準粒度分布における５０％径が０．１μｍ以上１０μｍ以下である固体電解質の粉末と一次粒子の数基準粒度分布における５０％径が５ｎｍ以上１００ｎｍ以下で且つ一次粒子の平均アスペクト比が２未満である粒状導電材とを混練して混合物Iを得、
　混合物Iと一次粒子の数基準粒度分布における５０％径が１００ｎｍ以上３μｍ以下である活物質の粉末とを混練して混合物IIを得、
　混合物IIと繊維平均径が１０ｎｍ以上１μｍ以下で且つ繊維平均径に対する繊維平均長さの比が２０以上である繊維状導電材とを混練して混合物IIIを得、
　次いで混合物IIIを圧縮成形することを有する。 The method for producing the electrode layer of the solid-state battery of the present invention is not particularly limited as long as it is a method having the above structure. The preferred method for producing the electrode layer of the solid-state battery of the present invention is as follows: the solid electrolyte powder having a 50% diameter in the volume-based particle size distribution of 0.1 μm or more and 10 μm or less and the 50% diameter in the number-based particle size distribution of primary particles. Is 5 nm or more and 100 nm or less and the average aspect ratio of the primary particles is less than 2 to obtain a mixture I by kneading,
A mixture II is obtained by kneading the mixture I and a powder of an active material having a 50% diameter in the number-based particle size distribution of primary particles of 100 nm or more and 3 μm or less,
Mixture II and a fibrous conductive material having an average fiber diameter of 10 nm or more and 1 μm or less and a ratio of the average fiber length to the average fiber diameter of 20 or more are kneaded to obtain a mixture III,
It then comprises compression molding the mixture III.
　混合物I、IIまたはIIIを得る際に行う混練においては、例えば、自転公転ミキサー、プラネタリミキサー、アトライタ、ボールミル、振動ミル、乳鉢、メカノフュージョン（ホソカワミクロン社製）等の混練装置を用いることができる。該混練は不活性ガス雰囲気下または真空下で行うことが好ましい。混練は、乾式または湿式のいずれによって行ってもよい。湿式混練において用いられる液体として、例えば、水、アルコール、Ｎ－メチル－２－ピロリドン等を挙げることができる。混練はメカニカルミリング法を用いて行うことが好ましい。混合物IIIは、スラリー、乾燥粉末などの状態で得られる。 In the kneading performed when obtaining the mixture I, II, or III, for example, a kneading device such as a rotation revolution mixer, a planetary mixer, an attritor, a ball mill, a vibration mill, a mortar, and mechanofusion (manufactured by Hosokawa Micron) can be used. The kneading is preferably performed under an inert gas atmosphere or under vacuum. The kneading may be performed by either a dry method or a wet method. Examples of the liquid used in the wet kneading include water, alcohol, N-methyl-2-pyrrolidone and the like. The kneading is preferably performed using a mechanical milling method. The mixture III is obtained in the form of a slurry, a dry powder or the like.
　固体電池は、一般的に、正極集電体、正電極層、固体電解質層、負電極層および負極集電体がこの順に積層された構造を成している。
　正極若しくは負極の集電体は、その材質が電気化学反応を起こさずに電子を伝導するものであれば特に限定されない。例えば、銅、アルミニウム、鉄等の金属単体若しくは合金、ＩＴＯ，ＡＴＯなどの導電性金属酸化物などで構成される。なお、導電体の表面に導電性接着層を設けてなる集電体を用いることもできる。導電性接着層は粒状導電材や繊維状導電材などを含むことができる。 A solid-state battery generally has a structure in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector are laminated in this order.
The current collector for the positive electrode or the negative electrode is not particularly limited as long as its material conducts electrons without causing an electrochemical reaction. For example, it is composed of a simple metal or alloy such as copper, aluminum and iron, and a conductive metal oxide such as ITO and ATO. A current collector having a conductive adhesive layer on the surface of the conductor can also be used. The conductive adhesive layer may include a granular conductive material, a fibrous conductive material, or the like.
　正極若しくは負極の電極層は、公知の粉末成形法によって得ることができる。例えば、正極集電体、正電極層用の粉末、固体電解質層用の粉末、負電極層用の粉末および負極集電体をこの順に重ね合わせて、それらを同時に粉末成形することによって、正電極層、固体電解質層および負電極層の形成と、正極集電体、正電極層、固体電解質、負電極層および負極集電体のそれぞれの間の接続を同時に行うこともできる。また、各層を逐次に粉末成形することもできる。得られた粉末成形品を、必要に応じて、焼成などの熱処理を施してもよい。 The positive electrode layer or the negative electrode layer can be obtained by a known powder molding method. For example, by stacking the positive electrode current collector, the positive electrode layer powder, the solid electrolyte layer powder, the negative electrode layer powder, and the negative electrode current collector in this order, and simultaneously molding them, the positive electrode The formation of the layer, the solid electrolyte layer and the negative electrode layer and the connection between each of the positive electrode current collector, the positive electrode layer, the solid electrolyte, the negative electrode layer and the negative electrode current collector can be performed at the same time. Further, each layer can be powder-molded sequentially. The obtained powder molded article may be subjected to heat treatment such as firing, if necessary.
　粉末成形法としては、例えば、スラリーを集電体に塗布し、乾燥させ、次いで加圧することを含む方法（ドクターブレード法）；スラリーを吸液性の金型に入れ、乾燥させ、次いで加圧することを含む方法（鋳込成形法）、粉末を所定形状の金型に入れ圧縮成形することを含む方法（金型成形法）、スラリーをダイスから押し出して成形することを含む押出成形法、粉末を遠心力により圧縮して成形することを含む遠心力法、粉末をロールプレス機に供給して圧延成形することを含む圧延成形法、粉末を所定形状の可撓性バッグに入れ、それを圧力媒体に入れて圧を加えることを含む冷間等方圧成形法（cold isostatic pressing）、粉末を所定形状の容器に入れ真空状態にし、その容器に圧力媒体にて圧を加えることを含む熱間等方圧成形法（hot isostatic pressing）などを挙げることができる。 As a powder molding method, for example, a method including applying a slurry to a current collector, drying and then applying pressure (doctor blade method); putting the slurry in a liquid-absorbing mold, drying, and then applying pressure Including the above (casting molding method), a method including placing the powder in a mold of a predetermined shape and compression-molding (mold molding method), an extrusion molding method including extruding the slurry from a die and molding, a powder Centrifugal force method including compressing and molding by centrifugal force, rolling molding method including supplying powder to a roll press machine and rolling forming, putting the powder into a flexible bag of a predetermined shape, and pressing it Cold isostatic pressing, which involves putting pressure in a medium (cold isostatic pressing), placing the powder in a container of a prescribed shape to create a vacuum, and applying pressure to the container with a pressure medium The isostatic pressing method (hot isostatic pressing) etc. can be mentioned.
　金型成形法としては、固定下パンチと固定ダイに粉末を入れ、可動上パンチで粉末に圧を加えることを含む片押し法；固定ダイに粉末を入れ、可動下パンチと可動上パンチで粉末に圧を加えることを含む両押し法；固定下パンチと可動ダイに粉末を入れ、可動上パンチで粉末に圧を加え圧が所定値を超えた時に可動ダイを移動させて固定下パンチが相対的に可動ダイの中に入り込むようにすることを含むフローティングダイ法；固定下パンチと可動ダイに粉末を入れ、可動上パンチで粉末に圧を加えると同時に可動ダイを移動させて固定下パンチが相対的に可動ダイの中に入り込むようにすることを含むウイズドロアル法などを挙げることができる。 The mold forming method includes a one-side pressing method in which powder is put in a fixed lower punch and a fixed die and pressure is applied to the powder by a movable upper punch; the powder is put in a fixed die and the powder is moved by a movable lower punch and a movable upper punch. Double pressing method including applying pressure to the fixed lower punch and the movable die. Put the powder into the fixed lower punch and the movable die, and move the movable die when the pressure exceeds the predetermined value by applying pressure to the powder with the movable upper punch. Floating die method, which involves moving the movable die vertically into the movable die; putting powder into the fixed lower punch and the movable die, applying pressure to the powder with the movable upper punch, and moving the movable die simultaneously There may be mentioned a withdrawal method including the step of moving into a relatively movable die.
　正電極層の厚さは、好ましくは１０～２００μｍ、より好ましくは３０～１５０μｍ、さらに好ましくは５０～１００μｍである。固体電解質層の厚さは、好ましくは５０ｎｍ～１０００μｍ、より好ましくは１００ｎｍ～１００μｍである。負電極層の厚さは、好ましくは１０～２００μｍ、より好ましくは３０～１５０μｍ、さらに好ましくは５０～１００μｍである。 The thickness of the positive electrode layer is preferably 10 to 200 μm, more preferably 30 to 150 μm, and further preferably 50 to 100 μm. The thickness of the solid electrolyte layer is preferably 50 nm to 1000 μm, more preferably 100 nm to 100 μm. The thickness of the negative electrode layer is preferably 10 to 200 μm, more preferably 30 to 150 μm, and further preferably 50 to 100 μm.
　以下に実施例を挙げて本発明を更に具体的に説明する。ただし、本発明の範囲は以下に示す実施例に限定されるものではない。 The present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the examples shown below.
〔体積基準粒度分布における５０％粒子径の測定〕
　試料粉末をイオン交換水に添加し、出力３０ｍＷで超音波処理を２分間行って分散液を得た。この分散液について、レーザー回折散乱式粒度分布測定装置を用いて、体積基準粒度分布を測定し、５０％粒子径を決定した。 [Measurement of 50% particle size in volume-based particle size distribution]
The sample powder was added to ion-exchanged water, and ultrasonic treatment was performed for 2 minutes at an output of 30 mW to obtain a dispersion liquid. The volume-based particle size distribution of this dispersion was measured using a laser diffraction/scattering particle size distribution analyzer, and the 50% particle size was determined.
〔繊維平均径、繊維平均長さ、数基準粒度分布における５０％粒子径〕
　試料を日本電子製ＦＥ－ＳＥＭ（ＪＳＭ－７６００Ｆ）により、ＳＥＩ(加速電圧５．０ｋＶ）のカラムモードにて１０視野観察し、その観察像から、繊維径および繊維長を計測し、それらの算術平均値を算出した。また、数基準粒度分布における５０％粒子径も同様に算出した。 [Fiber average diameter, fiber average length, 50% particle diameter in number standard particle size distribution]
The FE-SEM (JSM-7600F) manufactured by JEOL was used to observe 10 fields of view in the column mode of SEI (accelerating voltage 5.0 kV), and the fiber diameter and fiber length were measured from the observed image, and their arithmetic operations were performed. The average value was calculated. The 50% particle size in the number-based particle size distribution was also calculated in the same manner.
〔接触面積比の決定〕
　電極層を裁断し、断面を、日本電子製ＦＥ－ＳＥＭ（ＪＳＭ－７６００Ｆ）により、ＳＥＩ(加速電圧５．０ｋＶ）のカラムモードにて、１０視野観察した。
　活物質と固体電解質とが直接に接触している部分における、活物質と固体電解質とが直接に接している境界における各線分の長さＬaiを計測した。また、粒状導電材が活物質と固体電解質との間に介在している部分において、粒状導電材と活物質とが直接に接している境界における各線分の長さＬbjと、粒状導電材と固体電解質とが直接に接している境界における各線分の長さＬckとを計測した。
　活物質と固体電解質とが直接に接触している部分の合計面積に対する、粒状導電材が活物質と固体電解質との間に介在している部分における、粒状導電材と活物質とが直接に接触している部分の合計面積および粒状導電材と固体電解質とが直接に接触している部分の合計面積の総和の比（接触面積比）を、
Figure JPOXMLDOC01-appb-I000001
で算出した。なお、Σは各線分の長さの総和を表わす。 [Determination of contact area ratio]
The electrode layer was cut, and the cross section was observed with a FE-SEM (JSM-7600F) manufactured by JEOL in 10 fields of view in a column mode of SEI (accelerating voltage 5.0 kV).
The length La i of each line segment was measured at the boundary where the active material and the solid electrolyte were in direct contact with each other in the part where the active material was in direct contact with the solid electrolyte. Further, in a portion where the granular conductive material is interposed between the active material and the solid electrolyte, the length Lb j of each line segment at the boundary where the granular conductive material and the active material are in direct contact with each other, and the granular conductive material The length Lc k of each line segment at the boundary where the solid electrolyte is in direct contact was measured.
Direct contact between the granular conductive material and the active material in the area where the granular conductive material is present between the active material and the solid electrolyte, relative to the total area of the area where the active material and the solid electrolyte are in direct contact The ratio of the total area of the contacting parts and the total area of the parts in which the granular conductive material and the solid electrolyte are in direct contact (contact area ratio),
Figure JPOXMLDOC01-appb-I000001
Was calculated. Note that Σ represents the total length of the line segments.
〔密度、電気伝導度〕
　正極材粉末１５０ｍｇを電導度測定セル内に入れて、上下から圧力（０～５００ＭＰａ）を印加しながら定電流（１ｍＡ）にて、密度と電気伝導度とを同時に測定した。 [Density, electrical conductivity]
150 mg of the positive electrode material powder was put in an electric conductivity measuring cell, and the density and the electric conductivity were simultaneously measured at a constant current (1 mA) while applying a pressure (0 to 500 MPa) from above and below.
〔インピーダンス〕
　ＶｅｒｓａＳＴＡＴ４（Princeton Applied Research社製）を用いて、周波数:０．１Ｈｚ～１МＨｚ、振幅:５０ｍＶ、温度:２５℃の条件にて、入力の交流電圧信号に対する応答電流を測定した。得られたコールコール（Cole-Cole）プロット上の円弧が実数軸を切る部分の長さをインピーダンスＺとして算出した。円弧は界面での電荷の移動を伴うことを示すのでインピーダンスＺは反応抵抗と解釈できる。 [Impedance]
Using VersaSTAT4 (manufactured by Princeton Applied Research), the response current to the input AC voltage signal was measured under the conditions of frequency: 0.1 Hz to 1 MHZ, amplitude: 50 mV, and temperature: 25°C. The length of the portion where the arc on the obtained Cole-Cole plot cuts the real number axis was calculated as the impedance Z. The impedance Z can be interpreted as a reaction resistance because the arc indicates that the charge is transferred at the interface.
〔直流内部抵抗〕
　下記条件による充放電サイクルにおいて、直流電流の印加を休止した時と休止時から６００秒間経過した時との間における電圧変化（放電停止時は電圧上昇、充電停止時は電圧降下）ΔＶ（分極）を直流電流値Ｉで除することによって直流内部抵抗Ｒsを算出した。この算出法は、非特許文献１に記載されている方法である。
　充電過程：上限電圧３．９Ｖまで１２０ｍｉｎ充電－休止６００ｓｅｃの繰り返し、電流値：０．０５Ｃ相当
　放電過程：下限電圧２．０Ｖまで１２０ｍｉｎ放電－休止６００ｓｅｃの繰り返し、電流値：０．０５Ｃ相当
　温度：７０℃ (DC internal resistance)
In charging/discharging cycle under the following conditions, voltage change between when DC current application is stopped and when 600 seconds have passed from the stop (voltage rise when discharge is stopped, voltage drop when charge is stopped) ΔV (polarization) Was divided by the DC current value I to calculate the DC internal resistance R s . This calculation method is the method described in Non-Patent Document 1.
Charging process: 120 min charge up to 3.9 V upper limit-repetition of 600 sec pause, current value: 0.05 C Discharge process: 120 min discharge up to 2.0 V lower limit-repetition of 600 sec rest, current value: equivalent to 0.05 C Temperature: 70°C
〔原料〕
　粒状導電材（デンカブラック（登録商標）、ＨＳ－１００）： 一次粒子の数基準粒度分布における５０％径５０ｎｍ、一次粒子の平均アスペクト比１．１
　繊維状導電材（気相法炭素繊維（ＶＧＣＦ（登録商標）－Ｈ））：繊維平均径１５０ｎｍ、繊維平均径に対する繊維平均長さの比（アスペクト比）３５ 〔material〕
Granular conductive material (Denka Black (registered trademark), HS-100): 50% diameter 50 nm in number standard particle size distribution of primary particles, average aspect ratio of primary particles 1.1
Fibrous conductive material (vapor grown carbon fiber (VGCF (registered trademark)-H)): average fiber diameter 150 nm, ratio of average fiber length to average fiber diameter (aspect ratio) 35
実施例１
　アルゴン雰囲気下にて、硫化リチウム（Ｌｉ2Ｓ）０．６５１質量部と五硫化二リン（Ｐ2Ｓ5）１．３４９質量部とを混ぜ合わせ、該混合物をジルコニアボールとともに遊星式ボールミルに入れ２０時間、５００ｒｐｓにてメカニカルミリングを行って５０％径８μｍのＬｉＰＳ4粉末を得た。 Example 1
In an argon atmosphere, 0.651 parts by mass of lithium sulfide (Li 2 S) and 1.349 parts by mass of phosphorus pentasulfide (P 2 S 5 ) are mixed, and the mixture is put in a planetary ball mill together with zirconia balls. Mechanical milling was performed at 500 rps for 20 hours to obtain 50% diameter LiPS 4 powder having a diameter of 8 μm.
　ＬｉＰＳ4粉末３５．７質量部と粒状導電材（ＨＳ－１００）１質量部とを乳鉢で１０分間混ぜ合わせた。これに体積基準粒度分布における５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６１．３質量部を加え乳鉢で１０分間混ぜ合わせた。これに繊維状導電材（ＶＧＣＦ（登録商標）－Ｈ）２質量部を加え、乳鉢で１０分間混ぜ合わせ正極材粉末を得た。 35.7 parts by mass of LiPS 4 powder and 1 part by mass of the granular conductive material (HS-100) were mixed in a mortar for 10 minutes. To this, 61.3 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm in volume-based particle size distribution was added and mixed in a mortar for 10 minutes. 2 parts by mass of a fibrous conductive material (VGCF (registered trademark)-H) was added thereto, and mixed in a mortar for 10 minutes to obtain a positive electrode material powder.
　内径１０ｍｍのポリエチレン製ダイとＳＵＳ製の下パンチとを固定し、ＬｉＰＳ4粉末１５０質量部を入れ、上パンチにて２分間、１００ＭＰａで圧力を加え、固体電解質層を得た。上パンチを退かし、固体電解質層の上に正極材粉末１５質量部を入れ、上パンチにて２分間、４００ＭＰａの圧力を加えて、固体電解質層と正電極層との積層体を得た。下パンチを退かし、ダイの中に在る積層体の下に直径１００ｍｍ、厚さ１００μｍのＳＵＳ板を入れた。上パンチを退かし、ダイの中に在る積層体の上に直径１０ｍｍ、厚さ４７μｍのリチウム箔、および直径１０ｍｍ、厚さ２０μｍのアルミニウム箔２枚をこの順で載せた。下パンチ（負極端子）と上パンチ（正極端子）とに、８０ＭＰａの圧力を加え、その状態にてボルト固定して、負極端子、Ａｌ箔、Ｌｉ箔、固体電解質層、正電極層、ＳＵＳ板および正極端子からなる試験用固体電池を得た。正電極層は、接触面積比ＣＲが１．８５、密度ρが２．８１ｇ／ｃｍ3、電気伝導度σが０．１３９０Ｓ／ｃｍ-1であった。 A polyethylene die having an inner diameter of 10 mm and a SUS lower punch were fixed, 150 parts by mass of LiPS 4 powder was put therein, and pressure was applied with the upper punch for 2 minutes at 100 MPa to obtain a solid electrolyte layer. The upper punch was retracted, 15 parts by mass of the positive electrode material powder was put on the solid electrolyte layer, and a pressure of 400 MPa was applied by the upper punch for 2 minutes to obtain a laminate of the solid electrolyte layer and the positive electrode layer. .. The lower punch was retracted, and a SUS plate having a diameter of 100 mm and a thickness of 100 μm was put under the laminated body existing in the die. The upper punch was retracted, and a lithium foil having a diameter of 10 mm and a thickness of 47 μm and two aluminum foils having a diameter of 10 mm and a thickness of 20 μm were placed in this order on the laminate in the die. A pressure of 80 MPa is applied to the lower punch (negative electrode terminal) and the upper punch (positive electrode terminal), and bolts are fixed in that state, and the negative electrode terminal, Al foil, Li foil, solid electrolyte layer, positive electrode layer, SUS plate. A solid-state battery for testing, which was composed of and a positive electrode terminal, was obtained. The positive electrode layer had a contact area ratio CR of 1.85, a density ρ of 2.81 g/cm 3 , and an electrical conductivity σ of 0.1390 S/cm −1 .
　下パンチ（負極端子）および上パンチ（正極端子）に充放電試験器の端子をそれぞれ接続した。 The terminals of the charge/discharge tester were connected to the lower punch (negative electrode terminal) and the upper punch (positive electrode terminal), respectively.
　レストポテンシャルから１．２５ｍＡ（０．０５Ｃ）で４．２Ｖまで定電流充電を行い、次いで４．２Ｖで定電圧充電を４０時間行った。１．２５ｍＡ（０．０５Ｃ）にて２．７５Ｖまで定電流放電を行った。この放電時における正電極層中のＬｉＣｏＯ2の質量当たりの容量（放電容量Ｃ）は１４６．９ｍＡｈ／ｇであった。また、インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ２７６Ωおよび９８５Ωであった。 From the rest potential, constant current charging was performed at 1.25 mA (0.05 C) to 4.2 V, and then constant voltage charging was performed at 4.2 V for 40 hours. Constant current discharge was performed up to 2.75 V at 1.25 mA (0.05 C). The capacity per mass of LiCoO 2 in the positive electrode layer during this discharge (discharge capacity C) was 146.9 mAh/g. The impedance Z and the internal DC resistance Rs were 276Ω and 985Ω, respectively.
実施例２
　ＬｉＰＳ4粉末の量を３５．０質量部に、コバルト酸リチウム（ＬｉＣｏＯ2）の量を６０．０質量部に、繊維状導電材（ＶＧＣＦ（登録商標）－Ｈ）の量を４質量部にそれぞれ変えた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが３．８１、密度ρが２．７６ｇ／ｃｍ3、電気伝導度σが０．９０６０Ｓ／ｃｍ-1であった。また、放電容量Ｃは１３５．２ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ２６０Ωおよび９０８Ωであった。 Example 2
The amount of LiPS 4 powder was 35.0 parts by mass, the amount of lithium cobalt oxide (LiCoO 2 ) was 60.0 parts by mass, and the amount of the fibrous conductive material (VGCF (registered trademark)-H) was 4 parts by mass. A solid-state battery for test was obtained in the same manner as in Example 1 except that the respective conditions were changed. The positive electrode layer had a contact area ratio CR of 3.81, a density ρ of 2.76 g/cm 3 , and an electrical conductivity σ of 0.9060 S/cm −1 . The discharge capacity C was 135.2 mAh/g. The impedance Z and the DC internal resistance Rs were 260Ω and 908Ω, respectively.
比較例１
　５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６０質量部と粒状導電材（ＨＳ－１００）１質量部とを乳鉢で１０分間混ぜ合わせた。これにＬｉＰＳ4粉末３５質量部を加え乳鉢で１０分間混ぜ合わせた。これに繊維状導電材（ＶＧＣＦ（登録商標）－Ｈ）４質量部を加え、乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外が実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが０．０２、密度ρが２．７７ｇ／ｃｍ3、電気伝導度σが０．５２４０Ｓ／ｃｍ-1であった。また、放電容量Ｃは９０．１ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ７２７Ωおよび５３４４Ωであった。 Comparative Example 1
60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm and 1 part by mass of the granular conductive material (HS-100) were mixed in a mortar for 10 minutes. 35 parts by mass of LiPS 4 powder was added thereto and mixed in a mortar for 10 minutes. To this, 4 parts by mass of a fibrous conductive material (VGCF (registered trademark)-H) was added and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a contact area ratio CR of 0.02, a density ρ of 2.77 g/cm 3 , and an electrical conductivity σ of 0.5240 S/cm −1 . The discharge capacity C was 90.1 mAh/g. The impedance Z and the DC internal resistance Rs were 727Ω and 5344Ω, respectively.
比較例２
　ＬｉＰＳ4粉末３５質量部と繊維状導電材（ＶＧＣＦ（登録商標）－Ｈ）２．５質量部と５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６０質量部と粒状導電材（ＨＳ－１００）２．５質量部とを、乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが０．１３、密度ρが２．９５ｇ／ｃｍ3、電気伝導度σが０．４５３０Ｓ／ｃｍ-1であった。また、放電容量Ｃは２９．４ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ５０１Ωおよび９５３４Ωであった。 Comparative example 2
35 parts by mass of LiPS 4 powder, 2.5 parts by mass of fibrous conductive material (VGCF (registered trademark)-H), 60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm, and granular conductive material (HS-100). 2.5 parts by mass were mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a contact area ratio CR of 0.13, a density ρ of 2.95 g/cm 3 , and an electric conductivity σ of 0.4530 S/cm −1 . The discharge capacity C was 29.4 mAh/g. The impedance Z and the DC internal resistance Rs were 501Ω and 9534Ω, respectively.
比較例３
　ＬｉＰＳ4粉末３５質量部と繊維状導電材（ＶＧＣＦ（登録商標）－Ｈ）２質量部とを乳鉢で１０分間混ぜ合わせた。これに５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６０質量部を加え乳鉢で１０分間混ぜ合わせた。これに粒状導電材（ＨＳ－１００）１質量部を、乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが０．０６、密度ρが２．９２ｇ／ｃｍ3、電気伝導度σが０．０６４３Ｓ／ｃｍ-1であった。また、放電容量Ｃは１２５．０ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ１０００Ω超および１５００Ωであった。 Comparative Example 3
35 parts by mass of LiPS 4 powder and 2 parts by mass of fibrous conductive material (VGCF (registered trademark)-H) were mixed in a mortar for 10 minutes. To this, 60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm was added and mixed in a mortar for 10 minutes. 1 part by mass of the granular conductive material (HS-100) was mixed with this in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a contact area ratio CR of 0.06, a density ρ of 2.92 g/cm 3 , and an electrical conductivity σ of 0.0643 S/cm −1 . The discharge capacity C was 125.0 mAh/g. The impedance Z and the DC internal resistance Rs were over 1000Ω and 1500Ω, respectively.
比較例４
　ＬｉＰＳ4粉末３５質量部と粒状導電材（ＨＳ－１００）５質量部とを乳鉢で１０分間混ぜ合わせた。これに５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６０質量部を加え乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが１０．８９、密度ρが２．８０ｇ／ｃｍ3、電気伝導度σが０．００１４Ｓ／ｃｍ-1であった。また、放電容量Ｃは８５．４ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ１０００Ω超および４５５８Ωであった。 Comparative Example 4
35 parts by mass of LiPS 4 powder and 5 parts by mass of granular conductive material (HS-100) were mixed in a mortar for 10 minutes. 60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm was added thereto and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a contact area ratio CR of 10.89, a density ρ of 2.80 g/cm 3 , and an electric conductivity σ of 0.0014 S/cm −1 . The discharge capacity C was 85.4 mAh/g. The impedance Z and the DC internal resistance Rs were over 1000Ω and 4558Ω, respectively.
比較例５
　ＬｉＰＳ4粉末３５．７質量部と粒状導電材（ＨＳ－１００）３質量部とを乳鉢で１０分間混ぜ合わせた。これに５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６１．３質量部を加え乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、接触面積比ＣＲが４．５０、密度ρが２．７３ｇ／ｃｍ3、電気伝導度σが０．０００１Ｓ／ｃｍ-1であった。また、放電容量Ｃは１４２．１ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ３４８Ωおよび７９００Ωであった。 Comparative Example 5
35.7 parts by mass of LiPS 4 powder and 3 parts by mass of the granular conductive material (HS-100) were mixed in a mortar for 10 minutes. To this, 61.3 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm was added and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a contact area ratio CR of 4.50, a density ρ of 2.73 g/cm 3 , and an electrical conductivity σ of 0.0001 S/cm −1 . The discharge capacity C was 142.1 mAh/g. The impedance Z and the DC internal resistance Rs were 348Ω and 7900Ω, respectively.
比較例６
　ＬｉＰＳ4粉末３５質量部と気相法炭素繊維（ＶＧＣＦ（登録商標）－Ｈ）５質量部とを乳鉢で１０分間混ぜ合わせた。これに５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６０質量部を加え乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、密度ρが２．７６ｇ／ｃｍ3、電気伝導度σが０．８５６０Ｓ／ｃｍ-1であった。また、放電容量Ｃは１０２．９ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ１０００Ω超および１８２８Ωであった。 Comparative Example 6
35 parts by mass of LiPS 4 powder and 5 parts by mass of vapor grown carbon fiber (VGCF (registered trademark)-H) were mixed in a mortar for 10 minutes. 60 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm was added thereto and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a density ρ of 2.76 g/cm 3 and an electric conductivity σ of 0.8560 S/cm −1 . The discharge capacity C was 102.9 mAh/g. The impedance Z and the DC internal resistance Rs were over 1000Ω and 1828Ω, respectively.
比較例７
　ＬｉＰＳ4粉末３５．７質量部と気相法炭素繊維（ＶＧＣＦ（登録商標）－Ｈ）３質量部とを乳鉢で１０分間混ぜ合わせた。これに５０％径１０μｍのコバルト酸リチウム（ＬｉＣｏＯ2）６１．３質量部を加え乳鉢で１０分間混ぜ合わせて、正極材粉末を得た。この正極材粉末を用いた以外は実施例１と同じ方法で試験用固体電池を得た。正電極層は、密度ρが２．９３ｇ／ｃｍ3、電気伝導度σが０．０９４３Ｓ／ｃｍ-1であった。また、放電容量Ｃは１４９．１ｍＡｈ／ｇであった。インピーダンスＺおよび直流内部抵抗Ｒｓは、それぞれ１０００Ω超および１１１６Ωであった。 Comparative Example 7
35.7 parts by mass of LiPS 4 powder and 3 parts by mass of vapor grown carbon fiber (VGCF (registered trademark)-H) were mixed in a mortar for 10 minutes. To this, 61.3 parts by mass of lithium cobalt oxide (LiCoO 2 ) having a 50% diameter of 10 μm was added and mixed in a mortar for 10 minutes to obtain a positive electrode material powder. A test solid battery was obtained in the same manner as in Example 1 except that this positive electrode material powder was used. The positive electrode layer had a density ρ of 2.93 g/cm 3 and an electric conductivity σ of 0.0943 S/cm −1 . The discharge capacity C was 149.1 mAh/g. The impedance Z and the DC internal resistance Rs were over 1000Ω and 1116Ω, respectively.
　表１に結果を示す。本発明の電極層が、高い放電容量と、低いインピーダンス（反応抵抗）および低い直流内部抵抗を有する固体電池を提供できることを、示している。 The results are shown in Table 1. It is shown that the electrode layer of the present invention can provide a solid state battery having high discharge capacity, low impedance (reaction resistance) and low DC internal resistance.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002

Claims (8)

  1. 　活物質と、繊維状導電材と、粒状導電材と、固体電解質とを含み、
    　活物質と繊維状導電材と粒状導電材と固体電解質との合計量１００質量部に対して繊維状導電材と粒状導電材との合計量が０．５質量部以上７．０質量部以下であり、
    　活物質と固体電解質とが直接に接触している部分の合計面積に対する、粒状導電材が活物質と固体電解質との間に介在している部分における、粒状導電材と活物質とが直接に接触している部分の合計面積および粒状導電材と固体電解質とが直接に接触している部分の合計面積の総和の比が、０．８５以上４．７０以下である、
    　固体電池の電極層。     An active material, a fibrous conductive material, a granular conductive material, and a solid electrolyte,
    When the total amount of the fibrous conductive material and the granular conductive material is 0.5 parts by mass or more and 7.0 parts by mass or less based on 100 parts by mass of the total amount of the active material, the fibrous conductive material, the granular conductive material, and the solid electrolyte. Yes,
    Direct contact between the granular conductive material and the active material in the area where the granular conductive material is present between the active material and the solid electrolyte, relative to the total area of the area where the active material and the solid electrolyte are in direct contact The ratio of the total area of the contacting portion and the total area of the contacting portion of the granular conductive material and the solid electrolyte is 0.85 or more and 4.70 or less,
    Electrode layer of solid state battery.
  2. 　粒状導電材と繊維状導電材との合計量１００質量部に対して粒状導電材の量が１質量部以上５０質量部以下である、請求項１に記載の電極層。 The electrode layer according to claim 1, wherein the amount of the granular conductive material is 1 part by mass or more and 50 parts by mass or less based on 100 parts by mass of the total amount of the granular conductive material and the fibrous conductive material.
  3. 　粒状導電材は、一次粒子の数基準粒度分布における５０％径が５ｎｍ以上１００ｎｍ以下で且つ一次粒子の平均アスペクト比が２未満である炭素質炭素を含有する、請求項１または２に記載の電極層。 3. The electrode according to claim 1, wherein the granular conductive material contains carbonaceous carbon having a 50% diameter in a number-based particle size distribution of primary particles of 5 nm or more and 100 nm or less and an average aspect ratio of primary particles of less than 2. layer.
  4. 　繊維状導電材は、繊維平均径が１０ｎｍ以上１μｍ以下で且つ繊維平均径に対する繊維平均長さの比が２０以上である炭素質炭素または黒鉛質炭素を含有する、請求項１～３のいずれかひとつに記載の電極層。 The fibrous conductive material contains carbonaceous carbon or graphitic carbon having an average fiber diameter of 10 nm or more and 1 μm or less and a ratio of the average fiber length to the average fiber diameter of 20 or more. The electrode layer described in one.
  5. 　活物質は、体積基準粒度分布における５０％径が３μｍ以上５０μｍ以下である、請求項１～４のいずれかひとつに記載の電極層。 The electrode layer according to any one of claims 1 to 4, wherein the active material has a 50% diameter in a volume-based particle size distribution of 3 μm or more and 50 μm or less.
  6. 　活物質は、一次粒子の数基準粒度分布における５０％径が１００ｎｍ以上３μｍ以下である、請求項１～５のいずれかひとつに記載の電極層。 The electrode layer according to any one of claims 1 to 5, wherein the active material has a 50% diameter in a number-based particle size distribution of primary particles of 100 nm or more and 3 μm or less.
  7. 　請求項１～６のいずれかに記載の電極層と固体電解質層とを有する固体電池。 A solid battery having the electrode layer according to any one of claims 1 to 6 and a solid electrolyte layer.
  8. 　体積基準粒度分布における５０％径が０．１μｍ以上１０μｍ以下である固体電解質の粉末と一次粒子の数基準粒度分布における５０％径が５ｎｍ以上１００ｎｍ以下で且つ一次粒子の平均アスペクト比が２未満である粒状導電材とを混練して混合物Iを得、
    　混合物Iと一次粒子の数基準粒度分布における５０％径が１００ｎｍ以上３μｍ以下である活物質の粉末とを混練して混合物IIを得、
    　混合物IIと繊維平均径が１０ｎｍ以上１μｍ以下で且つ繊維平均径に対する繊維平均長さの比が２０以上である繊維状導電材とを混練して混合物IIIを得、
    　次いで混合物IIIを圧縮成形することを有する、
    　固体電池の電極層を製造する方法。     The solid electrolyte powder having a 50% diameter in the volume-based particle size distribution of 0.1 μm or more and 10 μm or less and the 50% diameter in the number-based particle size distribution of the primary particle is 5 nm or more and 100 nm or less and the average aspect ratio of the primary particles is less than 2. A mixture I is obtained by kneading with a certain granular conductive material,
    A mixture II is obtained by kneading the mixture I and a powder of an active material having a 50% diameter in the number-based particle size distribution of primary particles of 100 nm or more and 3 μm or less,
    Mixture II and a fibrous conductive material having an average fiber diameter of 10 nm or more and 1 μm or less and a ratio of the average fiber length to the average fiber diameter of 20 or more are kneaded to obtain a mixture III,
    Then compression molding the mixture III,
    A method for manufacturing an electrode layer of a solid-state battery.
PCT/JP2019/049776 2018-12-20 2019-12-19 Electrode layer of solid-state battery and solid-state battery WO2020130069A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2018-238620 2018-12-20
JP2018238620 2018-12-20
JP2019108924 2019-06-11
JP2019-108924 2019-06-11

Publications (1)

Publication Number Publication Date
WO2020130069A1 true WO2020130069A1 (en) 2020-06-25

Family

ID=71100863

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/049776 WO2020130069A1 (en) 2018-12-20 2019-12-19 Electrode layer of solid-state battery and solid-state battery

Country Status (2)

Country Link
TW (1) TWI735108B (en)
WO (1) WO2020130069A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023008005A1 (en) 2021-07-27 2023-02-02 パナソニックＩｐマネジメント株式会社 Positive electrode material and battery

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016009679A (en) * 2014-06-26 2016-01-18 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． All-solid-state lithium secondary battery
JP2016058277A (en) * 2014-09-10 2016-04-21 トヨタ自動車株式会社 Positive electrode mixture, positive electrode, solid battery and manufacturing methods thereof
JP2016062706A (en) * 2014-09-17 2016-04-25 積水化学工業株式会社 Method for manufacturing negative electrode for lithium ion secondary battery, and method for manufacturing lithium ion secondary battery
JP2016115636A (en) * 2014-12-17 2016-06-23 日産自動車株式会社 Negative electrode for electric device, and electric device using the same
JP2018041686A (en) * 2016-09-09 2018-03-15 日産自動車株式会社 Positive electrode for electric device and lithium ion battery using the same
WO2018110386A1 (en) * 2016-12-15 2018-06-21 昭和電工株式会社 Granular composite, negative electrode for lithium ion secondary battery, and method for manufacturing same
JP2019175554A (en) * 2018-03-26 2019-10-10 トヨタ自動車株式会社 Method for producing negative electrode mixture

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109417195A (en) * 2016-12-26 2019-03-01 昭和电工株式会社 All-solid-state lithium-ion battery

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016009679A (en) * 2014-06-26 2016-01-18 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． All-solid-state lithium secondary battery
JP2016058277A (en) * 2014-09-10 2016-04-21 トヨタ自動車株式会社 Positive electrode mixture, positive electrode, solid battery and manufacturing methods thereof
JP2016062706A (en) * 2014-09-17 2016-04-25 積水化学工業株式会社 Method for manufacturing negative electrode for lithium ion secondary battery, and method for manufacturing lithium ion secondary battery
JP2016115636A (en) * 2014-12-17 2016-06-23 日産自動車株式会社 Negative electrode for electric device, and electric device using the same
JP2018041686A (en) * 2016-09-09 2018-03-15 日産自動車株式会社 Positive electrode for electric device and lithium ion battery using the same
WO2018110386A1 (en) * 2016-12-15 2018-06-21 昭和電工株式会社 Granular composite, negative electrode for lithium ion secondary battery, and method for manufacturing same
JP2019175554A (en) * 2018-03-26 2019-10-10 トヨタ自動車株式会社 Method for producing negative electrode mixture

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023008005A1 (en) 2021-07-27 2023-02-02 パナソニックＩｐマネジメント株式会社 Positive electrode material and battery

Also Published As

Publication number Publication date
TW202036963A (en) 2020-10-01
TWI735108B (en) 2021-08-01

Similar Documents

Publication Publication Date Title
KR101862665B1 (en) Method for preparing a solid-state battery by sintering under pulsating current
JP5742905B2 (en) Positive electrode active material layer
JP7028354B2 (en) All-solid-state lithium-ion secondary battery
JP6776994B2 (en) Manufacturing method of all-solid-state lithium-ion secondary battery
JP6597701B2 (en) Negative electrode mixture, negative electrode including the negative electrode mixture, and all-solid-state lithium ion secondary battery including the negative electrode
US20170040643A1 (en) Method for preparing a solid-state battery by sintering under pulsating current
JP6927292B2 (en) All-solid-state lithium-ion secondary battery
JP2019160407A (en) All-solid battery
JP6776995B2 (en) Manufacturing method of all-solid-state lithium-ion secondary battery
WO2020130069A1 (en) Electrode layer of solid-state battery and solid-state battery
JP2020170605A (en) Negative electrode mixture layer
US20210151789A1 (en) All-solid-state battery
JP6593381B2 (en) Negative electrode mixture for all solid lithium ion secondary battery, negative electrode including the negative electrode mixture, and all solid lithium ion secondary battery including the negative electrode
JP6992710B2 (en) A composite solid electrolyte layer, a method for manufacturing the same, and a method for manufacturing an all-solid-state battery.
CN116231051B (en) Composite solid electrolyte, preparation method thereof, solid battery and power utilization device
WO2023007939A1 (en) Negative electrode material, negative electrode, battery, and method for producing same
JP2013206739A (en) Nonaqueous electrolyte battery, manufacturing method therefor, and electric vehicle including this battery
EP4329008A1 (en) All-solid-state electrochemical element and sulfur-carbon complex
JP2022156238A (en) All-solid battery
JP2021132005A (en) All-solid battery
TW202410517A (en) Method for producing sheet for solid-state secondary batteries, binder for solid-state secondary battery electrodes, composition for forming electrode, electrode mixture, and electrode
JP2023161322A (en) All-solid battery
JP2020119774A (en) Negative electrode
JP2022029464A (en) All-solid-state lithium-ion battery
JP2021051929A (en) Negative electrode material and manufacturing method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19900482

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19900482

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP